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33 files changed, 4757 insertions, 7 deletions
diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile index 300e1707893..e471bc466a7 100644 --- a/Documentation/DocBook/Makefile +++ b/Documentation/DocBook/Makefile @@ -9,7 +9,7 @@ DOCBOOKS := wanbook.xml z8530book.xml mcabook.xml videobook.xml \ kernel-hacking.xml kernel-locking.xml deviceiobook.xml \ procfs-guide.xml writing_usb_driver.xml networking.xml \ - kernel-api.xml filesystems.xml lsm.xml usb.xml \ + kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \ gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \ genericirq.xml s390-drivers.xml uio-howto.xml scsi.xml diff --git a/Documentation/DocBook/kgdb.tmpl b/Documentation/DocBook/kgdb.tmpl new file mode 100644 index 00000000000..97618bed4d6 --- /dev/null +++ b/Documentation/DocBook/kgdb.tmpl @@ -0,0 +1,447 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" + "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []> + +<book id="kgdbOnLinux"> + <bookinfo> + <title>Using kgdb and the kgdb Internals</title> + + <authorgroup> + <author> + <firstname>Jason</firstname> + <surname>Wessel</surname> + <affiliation> + <address> + <email>jason.wessel@windriver.com</email> + </address> + </affiliation> + </author> + </authorgroup> + + <authorgroup> + <author> + <firstname>Tom</firstname> + <surname>Rini</surname> + <affiliation> + <address> + <email>trini@kernel.crashing.org</email> + </address> + </affiliation> + </author> + </authorgroup> + + <authorgroup> + <author> + <firstname>Amit S.</firstname> + <surname>Kale</surname> + <affiliation> + <address> + <email>amitkale@linsyssoft.com</email> + </address> + </affiliation> + </author> + </authorgroup> + + <copyright> + <year>2008</year> + <holder>Wind River Systems, Inc.</holder> + </copyright> + <copyright> + <year>2004-2005</year> + <holder>MontaVista Software, Inc.</holder> + </copyright> + <copyright> + <year>2004</year> + <holder>Amit S. Kale</holder> + </copyright> + + <legalnotice> + <para> + This file is licensed under the terms of the GNU General Public License + version 2. This program is licensed "as is" without any warranty of any + kind, whether express or implied. + </para> + + </legalnotice> + </bookinfo> + +<toc></toc> + <chapter id="Introduction"> + <title>Introduction</title> + <para> + kgdb is a source level debugger for linux kernel. It is used along + with gdb to debug a linux kernel. The expectation is that gdb can + be used to "break in" to the kernel to inspect memory, variables + and look through a cal stack information similar to what an + application developer would use gdb for. It is possible to place + breakpoints in kernel code and perform some limited execution + stepping. + </para> + <para> + Two machines are required for using kgdb. One of these machines is a + development machine and the other is a test machine. The kernel + to be debugged runs on the test machine. The development machine + runs an instance of gdb against the vmlinux file which contains + the symbols (not boot image such as bzImage, zImage, uImage...). + In gdb the developer specifies the connection parameters and + connects to kgdb. Depending on which kgdb I/O modules exist in + the kernel for a given architecture, it may be possible to debug + the test machine's kernel with the development machine using a + rs232 or ethernet connection. + </para> + </chapter> + <chapter id="CompilingAKernel"> + <title>Compiling a kernel</title> + <para> + To enable <symbol>CONFIG_KGDB</symbol>, look under the "Kernel debugging" + and then select "KGDB: kernel debugging with remote gdb". + </para> + <para> + Next you should choose one of more I/O drivers to interconnect debugging + host and debugged target. Early boot debugging requires a KGDB + I/O driver that supports early debugging and the driver must be + built into the kernel directly. Kgdb I/O driver configuration + takes place via kernel or module parameters, see following + chapter. + </para> + <para> + The kgdb test compile options are described in the kgdb test suite chapter. + </para> + + </chapter> + <chapter id="EnableKGDB"> + <title>Enable kgdb for debugging</title> + <para> + In order to use kgdb you must activate it by passing configuration + information to one of the kgdb I/O drivers. If you do not pass any + configuration information kgdb will not do anything at all. Kgdb + will only actively hook up to the kernel trap hooks if a kgdb I/O + driver is loaded and configured. If you unconfigure a kgdb I/O + driver, kgdb will unregister all the kernel hook points. + </para> + <para> + All drivers can be reconfigured at run time, if + <symbol>CONFIG_SYSFS</symbol> and <symbol>CONFIG_MODULES</symbol> + are enabled, by echo'ing a new config string to + <constant>/sys/module/<driver>/parameter/<option></constant>. + The driver can be unconfigured by passing an empty string. You cannot + change the configuration while the debugger is attached. Make sure + to detach the debugger with the <constant>detach</constant> command + prior to trying unconfigure a kgdb I/O driver. + </para> + <sect1 id="kgdbwait"> + <title>Kernel parameter: kgdbwait</title> + <para> + The Kernel command line option <constant>kgdbwait</constant> makes + kgdb wait for a debugger connection during booting of a kernel. You + can only use this option you compiled a kgdb I/O driver into the + kernel and you specified the I/O driver configuration as a kernel + command line option. The kgdbwait parameter should always follow the + configuration parameter for the kgdb I/O driver in the kernel + command line else the I/O driver will not be configured prior to + asking the kernel to use it to wait. + </para> + <para> + The kernel will stop and wait as early as the I/O driver and + architecture will allow when you use this option. If you build the + kgdb I/O driver as a kernel module kgdbwait will not do anything. + </para> + </sect1> + <sect1 id="kgdboc"> + <title>Kernel parameter: kgdboc</title> + <para> + The kgdboc driver was originally an abbreviation meant to stand for + "kgdb over console". Kgdboc is designed to work with a single + serial port. It was meant to cover the circumstance + where you wanted to use a serial console as your primary console as + well as using it to perform kernel debugging. Of course you can + also use kgdboc without assigning a console to the same port. + </para> + <sect2 id="UsingKgdboc"> + <title>Using kgdboc</title> + <para> + You can configure kgdboc via sysfs or a module or kernel boot line + parameter depending on if you build with CONFIG_KGDBOC as a module + or built-in. + <orderedlist> + <listitem><para>From the module load or build-in</para> + <para><constant>kgdboc=<tty-device>,[baud]</constant></para> + <para> + The example here would be if your console port was typically ttyS0, you would use something like <constant>kgdboc=ttyS0,115200</constant> or on the ARM Versatile AB you would likely use <constant>kgdboc=ttyAMA0,115200</constant> + </para> + </listitem> + <listitem><para>From sysfs</para> + <para><constant>echo ttyS0 > /sys/module/kgdboc/parameters/kgdboc</constant></para> + </listitem> + </orderedlist> + </para> + <para> + NOTE: Kgdboc does not support interrupting the target via the + gdb remote protocol. You must manually send a sysrq-g unless you + have a proxy that splits console output to a terminal problem and + has a separate port for the debugger to connect to that sends the + sysrq-g for you. + </para> + <para>When using kgdboc with no debugger proxy, you can end up + connecting the debugger for one of two entry points. If an + exception occurs after you have loaded kgdboc a message should print + on the console stating it is waiting for the debugger. In case you + disconnect your terminal program and then connect the debugger in + its place. If you want to interrupt the target system and forcibly + enter a debug session you have to issue a Sysrq sequence and then + type the letter <constant>g</constant>. Then you disconnect the + terminal session and connect gdb. Your options if you don't like + this are to hack gdb to send the sysrq-g for you as well as on the + initial connect, or to use a debugger proxy that allows an + unmodified gdb to do the debugging. + </para> + </sect2> + </sect1> + <sect1 id="kgdbcon"> + <title>Kernel parameter: kgdbcon</title> + <para> + Kgdb supports using the gdb serial protocol to send console messages + to the debugger when the debugger is connected and running. There + are two ways to activate this feature. + <orderedlist> + <listitem><para>Activate with the kernel command line option:</para> + <para><constant>kgdbcon</constant></para> + </listitem> + <listitem><para>Use sysfs before configuring an io driver</para> + <para> + <constant>echo 1 > /sys/module/kgdb/parameters/kgdb_use_con</constant> + </para> + <para> + NOTE: If you do this after you configure the kgdb I/O driver, the + setting will not take effect until the next point the I/O is + reconfigured. + </para> + </listitem> + </orderedlist> + </para> + <para> + IMPORTANT NOTE: Using this option with kgdb over the console + (kgdboc) or kgdb over ethernet (kgdboe) is not supported. + </para> + </sect1> + </chapter> + <chapter id="ConnectingGDB"> + <title>Connecting gdb</title> + <para> + If you are using kgdboc, you need to have used kgdbwait as a boot + argument, issued a sysrq-g, or the system you are going to debug + has already taken an exception and is waiting for the debugger to + attach before you can connect gdb. + </para> + <para> + If you are not using different kgdb I/O driver other than kgdboc, + you should be able to connect and the target will automatically + respond. + </para> + <para> + Example (using a serial port): + </para> + <programlisting> + % gdb ./vmlinux + (gdb) set remotebaud 115200 + (gdb) target remote /dev/ttyS0 + </programlisting> + <para> + Example (kgdb to a terminal server): + </para> + <programlisting> + % gdb ./vmlinux + (gdb) target remote udp:192.168.2.2:6443 + </programlisting> + <para> + Example (kgdb over ethernet): + </para> + <programlisting> + % gdb ./vmlinux + (gdb) target remote udp:192.168.2.2:6443 + </programlisting> + <para> + Once connected, you can debug a kernel the way you would debug an + application program. + </para> + <para> + If you are having problems connecting or something is going + seriously wrong while debugging, it will most often be the case + that you want to enable gdb to be verbose about its target + communications. You do this prior to issuing the <constant>target + remote</constant> command by typing in: <constant>set remote debug 1</constant> + </para> + </chapter> + <chapter id="KGDBTestSuite"> + <title>kgdb Test Suite</title> + <para> + When kgdb is enabled in the kernel config you can also elect to + enable the config parameter KGDB_TESTS. Turning this on will + enable a special kgdb I/O module which is designed to test the + kgdb internal functions. + </para> + <para> + The kgdb tests are mainly intended for developers to test the kgdb + internals as well as a tool for developing a new kgdb architecture + specific implementation. These tests are not really for end users + of the Linux kernel. The primary source of documentation would be + to look in the drivers/misc/kgdbts.c file. + </para> + <para> + The kgdb test suite can also be configured at compile time to run + the core set of tests by setting the kernel config parameter + KGDB_TESTS_ON_BOOT. This particular option is aimed at automated + regression testing and does not require modifying the kernel boot + config arguments. If this is turned on, the kgdb test suite can + be disabled by specifying "kgdbts=" as a kernel boot argument. + </para> + </chapter> + <chapter id="CommonBackEndReq"> + <title>KGDB Internals</title> + <sect1 id="kgdbArchitecture"> + <title>Architecture Specifics</title> + <para> + Kgdb is organized into three basic components: + <orderedlist> + <listitem><para>kgdb core</para> + <para> + The kgdb core is found in kernel/kgdb.c. It contains: + <itemizedlist> + <listitem><para>All the logic to implement the gdb serial protocol</para></listitem> + <listitem><para>A generic OS exception handler which includes sync'ing the processors into a stopped state on an multi cpu system.</para></listitem> + <listitem><para>The API to talk to the kgdb I/O drivers</para></listitem> + <listitem><para>The API to make calls to the arch specific kgdb implementation</para></listitem> + <listitem><para>The logic to perform safe memory reads and writes to memory while using the debugger</para></listitem> + <listitem><para>A full implementation for software breakpoints unless overridden by the arch</para></listitem> + </itemizedlist> + </para> + </listitem> + <listitem><para>kgdb arch specific implementation</para> + <para> + This implementation is generally found in arch/*/kernel/kgdb.c. + As an example, arch/x86/kernel/kgdb.c contains the specifics to + implement HW breakpoint as well as the initialization to + dynamically register and unregister for the trap handlers on + this architecture. The arch specific portion implements: + <itemizedlist> + <listitem><para>contains an arch specific trap catcher which + invokes kgdb_handle_exception() to start kgdb about doing its + work</para></listitem> + <listitem><para>translation to and from gdb specific packet format to pt_regs</para></listitem> + <listitem><para>Registration and unregistration of architecture specific trap hooks</para></listitem> + <listitem><para>Any special exception handling and cleanup</para></listitem> + <listitem><para>NMI exception handling and cleanup</para></listitem> + <listitem><para>(optional)HW breakpoints</para></listitem> + </itemizedlist> + </para> + </listitem> + <listitem><para>kgdb I/O driver</para> + <para> + Each kgdb I/O driver has to provide an implemenation for the following: + <itemizedlist> + <listitem><para>configuration via builtin or module</para></listitem> + <listitem><para>dynamic configuration and kgdb hook registration calls</para></listitem> + <listitem><para>read and write character interface</para></listitem> + <listitem><para>A cleanup handler for unconfiguring from the kgdb core</para></listitem> + <listitem><para>(optional) Early debug methodology</para></listitem> + </itemizedlist> + Any given kgdb I/O driver has to operate very closely with the + hardware and must do it in such a way that does not enable + interrupts or change other parts of the system context without + completely restoring them. The kgdb core will repeatedly "poll" + a kgdb I/O driver for characters when it needs input. The I/O + driver is expected to return immediately if there is no data + available. Doing so allows for the future possibility to touch + watch dog hardware in such a way as to have a target system not + reset when these are enabled. + </para> + </listitem> + </orderedlist> + </para> + <para> + If you are intent on adding kgdb architecture specific support + for a new architecture, the architecture should define + <constant>HAVE_ARCH_KGDB</constant> in the architecture specific + Kconfig file. This will enable kgdb for the architecture, and + at that point you must create an architecture specific kgdb + implementation. + </para> + <para> + There are a few flags which must be set on every architecture in + their <asm/kgdb.h> file. These are: + <itemizedlist> + <listitem> + <para> + NUMREGBYTES: The size in bytes of all of the registers, so + that we can ensure they will all fit into a packet. + </para> + <para> + BUFMAX: The size in bytes of the buffer GDB will read into. + This must be larger than NUMREGBYTES. + </para> + <para> + CACHE_FLUSH_IS_SAFE: Set to 1 if it is always safe to call + flush_cache_range or flush_icache_range. On some architectures, + these functions may not be safe to call on SMP since we keep other + CPUs in a holding pattern. + </para> + </listitem> + </itemizedlist> + </para> + <para> + There are also the following functions for the common backend, + found in kernel/kgdb.c, that must be supplied by the + architecture-specific backend unless marked as (optional), in + which case a default function maybe used if the architecture + does not need to provide a specific implementation. + </para> +!Iinclude/linux/kgdb.h + </sect1> + <sect1 id="kgdbocDesign"> + <title>kgdboc internals</title> + <para> + The kgdboc driver is actually a very thin driver that relies on the + underlying low level to the hardware driver having "polling hooks" + which the to which the tty driver is attached. In the initial + implementation of kgdboc it the serial_core was changed to expose a + low level uart hook for doing polled mode reading and writing of a + single character while in an atomic context. When kgdb makes an I/O + request to the debugger, kgdboc invokes a call back in the serial + core which in turn uses the call back in the uart driver. It is + certainly possible to extend kgdboc to work with non-uart based + consoles in the future. + </para> + <para> + When using kgdboc with a uart, the uart driver must implement two callbacks in the <constant>struct uart_ops</constant>. Example from drivers/8250.c:<programlisting> +#ifdef CONFIG_CONSOLE_POLL + .poll_get_char = serial8250_get_poll_char, + .poll_put_char = serial8250_put_poll_char, +#endif + </programlisting> + Any implementation specifics around creating a polling driver use the + <constant>#ifdef CONFIG_CONSOLE_POLL</constant>, as shown above. + Keep in mind that polling hooks have to be implemented in such a way + that they can be called from an atomic context and have to restore + the state of the uart chip on return such that the system can return + to normal when the debugger detaches. You need to be very careful + with any kind of lock you consider, because failing here is most + going to mean pressing the reset button. + </para> + </sect1> + </chapter> + <chapter id="credits"> + <title>Credits</title> + <para> + The following people have contributed to this document: + <orderedlist> + <listitem><para>Amit Kale<email>amitkale@linsyssoft.com</email></para></listitem> + <listitem><para>Tom Rini<email>trini@kernel.crashing.org</email></para></listitem> + </orderedlist> + In March 2008 this document was completely rewritten by: + <itemizedlist> + <listitem><para>Jason Wessel<email>jason.wessel@windriver.com</email></para></listitem> + </itemizedlist> + </para> + </chapter> +</book> + diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index f9ea0803d5d..c867f506366 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -941,6 +941,11 @@ and is between 256 and 4096 characters. It is defined in the file kstack=N [X86-32,X86-64] Print N words from the kernel stack in oops dumps. + kgdboc= [HW] kgdb over consoles. + Requires a tty driver that supports console polling. + (only serial suported for now) + Format: <serial_device>[,baud] + l2cr= [PPC] lapic [X86-32,APIC] Enable the local APIC even if BIOS diff --git a/MAINTAINERS b/MAINTAINERS index e4677586801..3eceebb48c9 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2319,6 +2319,12 @@ L: linux-kernel@vger.kernel.org L: kexec@lists.infradead.org S: Maintained +KGDB +P: Jason Wessel +M: jason.wessel@windriver.com +L: kgdb-bugreport@lists.sourceforge.net +S: Maintained + KPROBES P: Ananth N Mavinakayanahalli M: ananth@in.ibm.com diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 701c4a27a73..2a59dbb2824 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -23,6 +23,7 @@ config X86 select HAVE_KPROBES select HAVE_KRETPROBES select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64) + select HAVE_ARCH_KGDB config GENERIC_LOCKBREAK diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 530ed6a4a03..c3920ea8ac5 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -67,6 +67,7 @@ obj-$(CONFIG_MODULES) += module_$(BITS).o obj-$(CONFIG_ACPI_SRAT) += srat_32.o obj-$(CONFIG_EFI) += efi.o efi_$(BITS).o efi_stub_$(BITS).o obj-$(CONFIG_DOUBLEFAULT) += doublefault_32.o +obj-$(CONFIG_KGDB) += kgdb.o obj-$(CONFIG_VM86) += vm86_32.o obj-$(CONFIG_EARLY_PRINTK) += early_printk.o diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c new file mode 100644 index 00000000000..8c7e555f6d3 --- /dev/null +++ b/arch/x86/kernel/kgdb.c @@ -0,0 +1,571 @@ +/* + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2, or (at your option) any + * later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + */ + +/* + * Copyright (C) 2004 Amit S. Kale <amitkale@linsyssoft.com> + * Copyright (C) 2000-2001 VERITAS Software Corporation. + * Copyright (C) 2002 Andi Kleen, SuSE Labs + * Copyright (C) 2004 LinSysSoft Technologies Pvt. Ltd. + * Copyright (C) 2007 MontaVista Software, Inc. + * Copyright (C) 2007-2008 Jason Wessel, Wind River Systems, Inc. + */ +/**************************************************************************** + * Contributor: Lake Stevens Instrument Division$ + * Written by: Glenn Engel $ + * Updated by: Amit Kale<akale@veritas.com> + * Updated by: Tom Rini <trini@kernel.crashing.org> + * Updated by: Jason Wessel <jason.wessel@windriver.com> + * Modified for 386 by Jim Kingdon, Cygnus Support. + * Origianl kgdb, compatibility with 2.1.xx kernel by + * David Grothe <dave@gcom.com> + * Integrated into 2.2.5 kernel by Tigran Aivazian <tigran@sco.com> + * X86_64 changes from Andi Kleen's patch merged by Jim Houston + */ +#include <linux/spinlock.h> +#include <linux/kdebug.h> +#include <linux/string.h> +#include <linux/kernel.h> +#include <linux/ptrace.h> +#include <linux/sched.h> +#include <linux/delay.h> +#include <linux/kgdb.h> +#include <linux/init.h> +#include <linux/smp.h> +#include <linux/nmi.h> + +#include <asm/apicdef.h> +#include <asm/system.h> + +#ifdef CONFIG_X86_32 +# include <mach_ipi.h> +#else +# include <asm/mach_apic.h> +#endif + +/* + * Put the error code here just in case the user cares: + */ +static int gdb_x86errcode; + +/* + * Likewise, the vector number here (since GDB only gets the signal + * number through the usual means, and that's not very specific): + */ +static int gdb_x86vector = -1; + +/** + * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs + * @gdb_regs: A pointer to hold the registers in the order GDB wants. + * @regs: The &struct pt_regs of the current process. + * + * Convert the pt_regs in @regs into the format for registers that + * GDB expects, stored in @gdb_regs. + */ +void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs) +{ + gdb_regs[GDB_AX] = regs->ax; + gdb_regs[GDB_BX] = regs->bx; + gdb_regs[GDB_CX] = regs->cx; + gdb_regs[GDB_DX] = regs->dx; + gdb_regs[GDB_SI] = regs->si; + gdb_regs[GDB_DI] = regs->di; + gdb_regs[GDB_BP] = regs->bp; + gdb_regs[GDB_PS] = regs->flags; + gdb_regs[GDB_PC] = regs->ip; +#ifdef CONFIG_X86_32 + gdb_regs[GDB_DS] = regs->ds; + gdb_regs[GDB_ES] = regs->es; + gdb_regs[GDB_CS] = regs->cs; + gdb_regs[GDB_SS] = __KERNEL_DS; + gdb_regs[GDB_FS] = 0xFFFF; + gdb_regs[GDB_GS] = 0xFFFF; +#else + gdb_regs[GDB_R8] = regs->r8; + gdb_regs[GDB_R9] = regs->r9; + gdb_regs[GDB_R10] = regs->r10; + gdb_regs[GDB_R11] = regs->r11; + gdb_regs[GDB_R12] = regs->r12; + gdb_regs[GDB_R13] = regs->r13; + gdb_regs[GDB_R14] = regs->r14; + gdb_regs[GDB_R15] = regs->r15; +#endif + gdb_regs[GDB_SP] = regs->sp; +} + +/** + * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs + * @gdb_regs: A pointer to hold the registers in the order GDB wants. + * @p: The &struct task_struct of the desired process. + * + * Convert the register values of the sleeping process in @p to + * the format that GDB expects. + * This function is called when kgdb does not have access to the + * &struct pt_regs and therefore it should fill the gdb registers + * @gdb_regs with what has been saved in &struct thread_struct + * thread field during switch_to. + */ +void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) +{ + gdb_regs[GDB_AX] = 0; + gdb_regs[GDB_BX] = 0; + gdb_regs[GDB_CX] = 0; + gdb_regs[GDB_DX] = 0; + gdb_regs[GDB_SI] = 0; + gdb_regs[GDB_DI] = 0; + gdb_regs[GDB_BP] = *(unsigned long *)p->thread.sp; +#ifdef CONFIG_X86_32 + gdb_regs[GDB_DS] = __KERNEL_DS; + gdb_regs[GDB_ES] = __KERNEL_DS; + gdb_regs[GDB_PS] = 0; + gdb_regs[GDB_CS] = __KERNEL_CS; + gdb_regs[GDB_PC] = p->thread.ip; + gdb_regs[GDB_SS] = __KERNEL_DS; + gdb_regs[GDB_FS] = 0xFFFF; + gdb_regs[GDB_GS] = 0xFFFF; +#else + gdb_regs[GDB_PS] = *(unsigned long *)(p->thread.sp + 8); + gdb_regs[GDB_PC] = 0; + gdb_regs[GDB_R8] = 0; + gdb_regs[GDB_R9] = 0; + gdb_regs[GDB_R10] = 0; + gdb_regs[GDB_R11] = 0; + gdb_regs[GDB_R12] = 0; + gdb_regs[GDB_R13] = 0; + gdb_regs[GDB_R14] = 0; + gdb_regs[GDB_R15] = 0; +#endif + gdb_regs[GDB_SP] = p->thread.sp; +} + +/** + * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs. + * @gdb_regs: A pointer to hold the registers we've received from GDB. + * @regs: A pointer to a &struct pt_regs to hold these values in. + * + * Convert the GDB regs in @gdb_regs into the pt_regs, and store them + * in @regs. + */ +void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) +{ + regs->ax = gdb_regs[GDB_AX]; + regs->bx = gdb_regs[GDB_BX]; + regs->cx = gdb_regs[GDB_CX]; + regs->dx = gdb_regs[GDB_DX]; + regs->si = gdb_regs[GDB_SI]; + regs->di = gdb_regs[GDB_DI]; + regs->bp = gdb_regs[GDB_BP]; + regs->flags = gdb_regs[GDB_PS]; + regs->ip = gdb_regs[GDB_PC]; +#ifdef CONFIG_X86_32 + regs->ds = gdb_regs[GDB_DS]; + regs->es = gdb_regs[GDB_ES]; + regs->cs = gdb_regs[GDB_CS]; +#else + regs->r8 = gdb_regs[GDB_R8]; + regs->r9 = gdb_regs[GDB_R9]; + regs->r10 = gdb_regs[GDB_R10]; + regs->r11 = gdb_regs[GDB_R11]; + regs->r12 = gdb_regs[GDB_R12]; + regs->r13 = gdb_regs[GDB_R13]; + regs->r14 = gdb_regs[GDB_R14]; + regs->r15 = gdb_regs[GDB_R15]; +#endif +} + +static struct hw_breakpoint { + unsigned enabled; + unsigned type; + unsigned len; + unsigned long addr; +} breakinfo[4]; + +static void kgdb_correct_hw_break(void) +{ + unsigned long dr7; + int correctit = 0; + int breakbit; + int breakno; + + get_debugreg(dr7, 7); + for (breakno = 0; breakno < 4; breakno++) { + breakbit = 2 << (breakno << 1); + if (!(dr7 & breakbit) && breakinfo[breakno].enabled) { + correctit = 1; + dr7 |= breakbit; + dr7 &= ~(0xf0000 << (breakno << 2)); + dr7 |= ((breakinfo[breakno].len << 2) | + breakinfo[breakno].type) << + ((breakno << 2) + 16); + if (breakno >= 0 && breakno <= 3) + set_debugreg(breakinfo[breakno].addr, breakno); + + } else { + if ((dr7 & breakbit) && !breakinfo[breakno].enabled) { + correctit = 1; + dr7 &= ~breakbit; + dr7 &= ~(0xf0000 << (breakno << 2)); + } + } + } + if (correctit) + set_debugreg(dr7, 7); +} + +static int +kgdb_remove_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype) +{ + int i; + + for (i = 0; i < 4; i++) + if (breakinfo[i].addr == addr && breakinfo[i].enabled) + break; + if (i == 4) + return -1; + + breakinfo[i].enabled = 0; + + return 0; +} + +static void kgdb_remove_all_hw_break(void) +{ + int i; + + for (i = 0; i < 4; i++) + memset(&breakinfo[i], 0, sizeof(struct hw_breakpoint)); +} + +static int +kgdb_set_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype) +{ + unsigned type; + int i; + + for (i = 0; i < 4; i++) + if (!breakinfo[i].enabled) + break; + if (i == 4) + return -1; + + switch (bptype) { + case BP_HARDWARE_BREAKPOINT: + type = 0; + len = 1; + break; + case BP_WRITE_WATCHPOINT: + type = 1; + break; + case BP_ACCESS_WATCHPOINT: + type = 3; + break; + default: + return -1; + } + + if (len == 1 || len == 2 || len == 4) + breakinfo[i].len = len - 1; + else + return -1; + + breakinfo[i].enabled = 1; + breakinfo[i].addr = addr; + breakinfo[i].type = type; + + return 0; +} + +/** + * kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb. + * @regs: Current &struct pt_regs. + * + * This function will be called if the particular architecture must + * disable hardware debugging while it is processing gdb packets or + * handling exception. + */ +void kgdb_disable_hw_debug(struct pt_regs *regs) +{ + /* Disable hardware debugging while we are in kgdb: */ + set_debugreg(0UL, 7); +} + +/** + * kgdb_post_primary_code - Save error vector/code numbers. + * @regs: Original pt_regs. + * @e_vector: Original error vector. + * @err_code: Original error code. + * + * This is needed on architectures which support SMP and KGDB. + * This function is called after all the slave cpus have been put + * to a know spin state and the primary CPU has control over KGDB. + */ +void kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code) +{ + /* primary processor is completely in the debugger */ + gdb_x86vector = e_vector; + gdb_x86errcode = err_code; +} + +#ifdef CONFIG_SMP +/** + * kgdb_roundup_cpus - Get other CPUs into a holding pattern + * @flags: Current IRQ state + * + * On SMP systems, we need to get the attention of the other CPUs + * and get them be in a known state. This should do what is needed + * to get the other CPUs to call kgdb_wait(). Note that on some arches, + * the NMI approach is not used for rounding up all the CPUs. For example, + * in case of MIPS, smp_call_function() is used to roundup CPUs. In + * this case, we have to make sure that interrupts are enabled before + * calling smp_call_function(). The argument to this function is + * the flags that will be used when restoring the interrupts. There is + * local_irq_save() call before kgdb_roundup_cpus(). + * + * On non-SMP systems, this is not called. + */ +void kgdb_roundup_cpus(unsigned long flags) +{ + send_IPI_allbutself(APIC_DM_NMI); +} +#endif + +/** + * kgdb_arch_handle_exception - Handle architecture specific GDB packets. + * @vector: The error vector of the exception that happened. + * @signo: The signal number of the exception that happened. + * @err_code: The error code of the exception that happened. + * @remcom_in_buffer: The buffer of the packet we have read. + * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into. + * @regs: The &struct pt_regs of the current process. + * + * This function MUST handle the 'c' and 's' command packets, + * as well packets to set / remove a hardware breakpoint, if used. + * If there are additional packets which the hardware needs to handle, + * they are handled here. The code should return -1 if it wants to + * process more packets, and a %0 or %1 if it wants to exit from the + * kgdb callback. + */ +int kgdb_arch_handle_exception(int e_vector, int signo, int err_code, + char *remcomInBuffer, char *remcomOutBuffer, + struct pt_regs *linux_regs) +{ + unsigned long addr; + unsigned long dr6; + char *ptr; + int newPC; + + switch (remcomInBuffer[0]) { + case 'c': + case 's': + /* try to read optional parameter, pc unchanged if no parm */ + ptr = &remcomInBuffer[1]; + if (kgdb_hex2long(&ptr, &addr)) + linux_regs->ip = addr; + case 'D': + case 'k': + newPC = linux_regs->ip; + + /* clear the trace bit */ + linux_regs->flags &= ~TF_MASK; + atomic_set(&kgdb_cpu_doing_single_step, -1); + + /* set the trace bit if we're stepping */ + if (remcomInBuffer[0] == 's') { + linux_regs->flags |= TF_MASK; + kgdb_single_step = 1; + if (kgdb_contthread) { + atomic_set(&kgdb_cpu_doing_single_step, + raw_smp_processor_id()); + } + } + + get_debugreg(dr6, 6); + if (!(dr6 & 0x4000)) { + int breakno; + + for (breakno = 0; breakno < 4; breakno++) { + if (dr6 & (1 << breakno) && + breakinfo[breakno].type == 0) { + /* Set restore flag: */ + linux_regs->flags |= X86_EFLAGS_RF; + break; + } + } + } + set_debugreg(0UL, 6); + kgdb_correct_hw_break(); + + return 0; + } + + /* this means that we do not want to exit from the handler: */ + return -1; +} + +static inline int +single_step_cont(struct pt_regs *regs, struct die_args *args) +{ + /* + * Single step exception from kernel space to user space so + * eat the exception and continue the process: + */ + printk(KERN_ERR "KGDB: trap/step from kernel to user space, " + "resuming...\n"); + kgdb_arch_handle_exception(args->trapnr, args->signr, + args->err, "c", "", regs); + + return NOTIFY_STOP; +} + +static int was_in_debug_nmi[NR_CPUS]; + +static int __kgdb_notify(struct die_args *args, unsigned long cmd) +{ + struct pt_regs *regs = args->regs; + + switch (cmd) { + case DIE_NMI: + if (atomic_read(&kgdb_active) != -1) { + /* KGDB CPU roundup */ + kgdb_nmicallback(raw_smp_processor_id(), regs); + was_in_debug_nmi[raw_smp_processor_id()] = 1; + touch_nmi_watchdog(); + return NOTIFY_STOP; + } + return NOTIFY_DONE; + + case DIE_NMI_IPI: + if (atomic_read(&kgdb_active) != -1) { + /* KGDB CPU roundup */ + kgdb_nmicallback(raw_smp_processor_id(), regs); + was_in_debug_nmi[raw_smp_processor_id()] = 1; + touch_nmi_watchdog(); + } + return NOTIFY_DONE; + + case DIE_NMIUNKNOWN: + if (was_in_debug_nmi[raw_smp_processor_id()]) { + was_in_debug_nmi[raw_smp_processor_id()] = 0; + return NOTIFY_STOP; + } + return NOTIFY_DONE; + + case DIE_NMIWATCHDOG: + if (atomic_read(&kgdb_active) != -1) { + /* KGDB CPU roundup: */ + kgdb_nmicallback(raw_smp_processor_id(), regs); + return NOTIFY_STOP; + } + /* Enter debugger: */ + break; + + case DIE_DEBUG: + if (atomic_read(&kgdb_cpu_doing_single_step) == + raw_smp_processor_id() && + user_mode(regs)) + return single_step_cont(regs, args); + /* fall through */ + default: + if (user_mode(regs)) + return NOTIFY_DONE; + } + + if (kgdb_handle_exception(args->trapnr, args->signr, args->err, regs)) + return NOTIFY_DONE; + + /* Must touch watchdog before return to normal operation */ + touch_nmi_watchdog(); + return NOTIFY_STOP; +} + +static int +kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr) +{ + unsigned long flags; + int ret; + + local_irq_save(flags); + ret = __kgdb_notify(ptr, cmd); + local_irq_restore(flags); + + return ret; +} + +static struct notifier_block kgdb_notifier = { + .notifier_call = kgdb_notify, + + /* + * Lowest-prio notifier priority, we want to be notified last: + */ + .priority = -INT_MAX, +}; + +/** + * kgdb_arch_init - Perform any architecture specific initalization. + * + * This function will handle the initalization of any architecture + * specific callbacks. + */ +int kgdb_arch_init(void) +{ + return register_die_notifier(&kgdb_notifier); +} + +/** + * kgdb_arch_exit - Perform any architecture specific uninitalization. + * + * This function will handle the uninitalization of any architecture + * specific callbacks, for dynamic registration and unregistration. + */ +void kgdb_arch_exit(void) +{ + unregister_die_notifier(&kgdb_notifier); +} + +/** + * + * kgdb_skipexception - Bail out of KGDB when we've been triggered. + * @exception: Exception vector number + * @regs: Current &struct pt_regs. + * + * On some architectures we need to skip a breakpoint exception when + * it occurs after a breakpoint has been removed. + * + * Skip an int3 exception when it occurs after a breakpoint has been + * removed. Backtrack eip by 1 since the int3 would have caused it to + * increment by 1. + */ +int kgdb_skipexception(int exception, struct pt_regs *regs) +{ + if (exception == 3 && kgdb_isremovedbreak(regs->ip - 1)) { + regs->ip -= 1; + return 1; + } + return 0; +} + +unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs) +{ + if (exception == 3) + return instruction_pointer(regs) - 1; + return instruction_pointer(regs); +} + +struct kgdb_arch arch_kgdb_ops = { + /* Breakpoint instruction: */ + .gdb_bpt_instr = { 0xcc }, + .flags = KGDB_HW_BREAKPOINT, + .set_hw_breakpoint = kgdb_set_hw_break, + .remove_hw_breakpoint = kgdb_remove_hw_break, + .remove_all_hw_break = kgdb_remove_all_hw_break, + .correct_hw_break = kgdb_correct_hw_break, +}; diff --git a/arch/x86/kernel/setup64.c b/arch/x86/kernel/setup64.c index 4be499cd6a0..9042fb0e36f 100644 --- a/arch/x86/kernel/setup64.c +++ b/arch/x86/kernel/setup64.c @@ -11,6 +11,7 @@ #include <linux/bootmem.h> #include <linux/bitops.h> #include <linux/module.h> +#include <linux/kgdb.h> #include <asm/pda.h> #include <asm/pgtable.h> #include <asm/processor.h> @@ -251,6 +252,17 @@ void __cpuinit cpu_init (void) load_TR_desc(); load_LDT(&init_mm.context); +#ifdef CONFIG_KGDB + /* + * If the kgdb is connected no debug regs should be altered. This + * is only applicable when KGDB and a KGDB I/O module are built + * into the kernel and you are using early debugging with + * kgdbwait. KGDB will control the kernel HW breakpoint registers. + */ + if (kgdb_connected && arch_kgdb_ops.correct_hw_break) + arch_kgdb_ops.correct_hw_break(); + else { +#endif /* * Clear all 6 debug registers: */ @@ -261,6 +273,10 @@ void __cpuinit cpu_init (void) set_debugreg(0UL, 3); set_debugreg(0UL, 6); set_debugreg(0UL, 7); +#ifdef CONFIG_KGDB + /* If the kgdb is connected no debug regs should be altered. */ + } +#endif fpu_init(); diff --git a/arch/x86/kernel/traps_32.c b/arch/x86/kernel/traps_32.c index bb9107c56ff..65791ca2824 100644 --- a/arch/x86/kernel/traps_32.c +++ b/arch/x86/kernel/traps_32.c @@ -730,6 +730,8 @@ io_check_error(unsigned char reason, struct pt_regs *regs) static __kprobes void unknown_nmi_error(unsigned char reason, struct pt_regs *regs) { + if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP) + return; #ifdef CONFIG_MCA /* * Might actually be able to figure out what the guilty party diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c index 33292ac814f..79aa6fc0815 100644 --- a/arch/x86/kernel/traps_64.c +++ b/arch/x86/kernel/traps_64.c @@ -602,8 +602,13 @@ void die(const char * str, struct pt_regs * regs, long err) void __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic) { - unsigned long flags = oops_begin(); + unsigned long flags; + if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == + NOTIFY_STOP) + return; + + flags = oops_begin(); /* * We are in trouble anyway, lets at least try * to get a message out. @@ -808,6 +813,8 @@ io_check_error(unsigned char reason, struct pt_regs * regs) static __kprobes void unknown_nmi_error(unsigned char reason, struct pt_regs * regs) { + if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP) + return; printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n", reason); printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n"); diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 613ec816ce6..4d3c7018f0c 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -1155,6 +1155,48 @@ static struct tty_driver *get_tty_driver(dev_t device, int *index) return NULL; } +#ifdef CONFIG_CONSOLE_POLL + +/** + * tty_find_polling_driver - find device of a polled tty + * @name: name string to match + * @line: pointer to resulting tty line nr + * + * This routine returns a tty driver structure, given a name + * and the condition that the tty driver is capable of polled + * operation. + */ +struct tty_driver *tty_find_polling_driver(char *name, int *line) +{ + struct tty_driver *p, *res = NULL; + int tty_line = 0; + char *str; + + mutex_lock(&tty_mutex); + /* Search through the tty devices to look for a match */ + list_for_each_entry(p, &tty_drivers, tty_drivers) { + str = name + strlen(p->name); + tty_line = simple_strtoul(str, &str, 10); + if (*str == ',') + str++; + if (*str == '\0') + str = 0; + + if (tty_line >= 0 && tty_line <= p->num && p->poll_init && + !p->poll_init(p, tty_line, str)) { + + res = p; + *line = tty_line; + break; + } + } + mutex_unlock(&tty_mutex); + + return res; +} +EXPORT_SYMBOL_GPL(tty_find_polling_driver); +#endif + /** * tty_check_change - check for POSIX terminal changes * @tty: tty to check @@ -3850,6 +3892,11 @@ void tty_set_operations(struct tty_driver *driver, driver->write_proc = op->write_proc; driver->tiocmget = op->tiocmget; driver->tiocmset = op->tiocmset; +#ifdef CONFIG_CONSOLE_POLL + driver->poll_init = op->poll_init; + driver->poll_get_char = op->poll_get_char; + driver->poll_put_char = op->poll_put_char; +#endif } diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index 3b12f5da856..bbc69fdd1b9 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -22,3 +22,4 @@ obj-$(CONFIG_FUJITSU_LAPTOP) += fujitsu-laptop.o obj-$(CONFIG_EEPROM_93CX6) += eeprom_93cx6.o obj-$(CONFIG_INTEL_MENLOW) += intel_menlow.o obj-$(CONFIG_ENCLOSURE_SERVICES) += enclosure.o +obj-$(CONFIG_KGDB_TESTS) += kgdbts.o diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c new file mode 100644 index 00000000000..6d6286c4eea --- /dev/null +++ b/drivers/misc/kgdbts.c @@ -0,0 +1,1090 @@ +/* + * kgdbts is a test suite for kgdb for the sole purpose of validating + * that key pieces of the kgdb internals are working properly such as + * HW/SW breakpoints, single stepping, and NMI. + * + * Created by: Jason Wessel <jason.wessel@windriver.com> + * + * Copyright (c) 2008 Wind River Systems, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + * See the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +/* Information about the kgdb test suite. + * ------------------------------------- + * + * The kgdb test suite is designed as a KGDB I/O module which + * simulates the communications that a debugger would have with kgdb. + * The tests are broken up in to a line by line and referenced here as + * a "get" which is kgdb requesting input and "put" which is kgdb + * sending a response. + * + * The kgdb suite can be invoked from the kernel command line + * arguments system or executed dynamically at run time. The test + * suite uses the variable "kgdbts" to obtain the information about + * which tests to run and to configure the verbosity level. The + * following are the various characters you can use with the kgdbts= + * line: + * + * When using the "kgdbts=" you only choose one of the following core + * test types: + * A = Run all the core tests silently + * V1 = Run all the core tests with minimal output + * V2 = Run all the core tests in debug mode + * + * You can also specify optional tests: + * N## = Go to sleep with interrupts of for ## seconds + * to test the HW NMI watchdog + * F## = Break at do_fork for ## iterations + * S## = Break at sys_open for ## iterations + * + * NOTE: that the do_fork and sys_open tests are mutually exclusive. + * + * To invoke the kgdb test suite from boot you use a kernel start + * argument as follows: + * kgdbts=V1 kgdbwait + * Or if you wanted to perform the NMI test for 6 seconds and do_fork + * test for 100 forks, you could use: + * kgdbts=V1N6F100 kgdbwait + * + * The test suite can also be invoked at run time with: + * echo kgdbts=V1N6F100 > /sys/module/kgdbts/parameters/kgdbts + * Or as another example: + * echo kgdbts=V2 > /sys/module/kgdbts/parameters/kgdbts + * + * When developing a new kgdb arch specific implementation or + * using these tests for the purpose of regression testing, + * several invocations are required. + * + * 1) Boot with the test suite enabled by using the kernel arguments + * "kgdbts=V1F100 kgdbwait" + * ## If kgdb arch specific implementation has NMI use + * "kgdbts=V1N6F100 + * + * 2) After the system boot run the basic test. + * echo kgdbts=V1 > /sys/module/kgdbts/parameters/kgdbts + * + * 3) Run the concurrency tests. It is best to use n+1 + * while loops where n is the number of cpus you have + * in your system. The example below uses only two + * loops. + * + * ## This tests break points on sys_open + * while [ 1 ] ; do find / > /dev/null 2>&1 ; done & + * while [ 1 ] ; do find / > /dev/null 2>&1 ; done & + * echo kgdbts=V1S10000 > /sys/module/kgdbts/parameters/kgdbts + * fg # and hit control-c + * fg # and hit control-c + * ## This tests break points on do_fork + * while [ 1 ] ; do date > /dev/null ; done & + * while [ 1 ] ; do date > /dev/null ; done & + * echo kgdbts=V1F1000 > /sys/module/kgdbts/parameters/kgdbts + * fg # and hit control-c + * + */ + +#include <linux/kernel.h> +#include <linux/kgdb.h> +#include <linux/ctype.h> +#include <linux/uaccess.h> +#include <linux/syscalls.h> +#include <linux/nmi.h> +#include <linux/delay.h> +#include <linux/kthread.h> +#include <linux/delay.h> + +#define v1printk(a...) do { \ + if (verbose) \ + printk(KERN_INFO a); \ + } while (0) +#define v2printk(a...) do { \ + if (verbose > 1) \ + printk(KERN_INFO a); \ + touch_nmi_watchdog(); \ + } while (0) +#define eprintk(a...) do { \ + printk(KERN_ERR a); \ + WARN_ON(1); \ + } while (0) +#define MAX_CONFIG_LEN 40 + +static const char hexchars[] = "0123456789abcdef"; +static struct kgdb_io kgdbts_io_ops; +static char get_buf[BUFMAX]; +static int get_buf_cnt; +static char put_buf[BUFMAX]; +static int put_buf_cnt; +static char scratch_buf[BUFMAX]; +static int verbose; +static int repeat_test; +static int test_complete; +static int send_ack; +static int final_ack; +static int hw_break_val; +static int hw_break_val2; +#if defined(CONFIG_ARM) || defined(CONFIG_MIPS) +static int arch_needs_sstep_emulation = 1; +#else +static int arch_needs_sstep_emulation; +#endif +static unsigned long sstep_addr; +static int sstep_state; + +/* Storage for the registers, in GDB format. */ +static unsigned long kgdbts_gdb_regs[(NUMREGBYTES + + sizeof(unsigned long) - 1) / + sizeof(unsigned long)]; +static struct pt_regs kgdbts_regs; + +/* -1 = init not run yet, 0 = unconfigured, 1 = configured. */ +static int configured = -1; + +#ifdef CONFIG_KGDB_TESTS_BOOT_STRING +static char config[MAX_CONFIG_LEN] = CONFIG_KGDB_TESTS_BOOT_STRING; +#else +static char config[MAX_CONFIG_LEN]; +#endif +static struct kparam_string kps = { + .string = config, + .maxlen = MAX_CONFIG_LEN, +}; + +static void fill_get_buf(char *buf); + +struct test_struct { + char *get; + char *put; + void (*get_handler)(char *); + int (*put_handler)(char *, char *); +}; + +struct test_state { + char *name; + struct test_struct *tst; + int idx; + int (*run_test) (int, int); + int (*validate_put) (char *); +}; + +static struct test_state ts; + +static int kgdbts_unreg_thread(void *ptr) +{ + /* Wait until the tests are complete and then ungresiter the I/O + * driver. + */ + while (!final_ack) + msleep_interruptible(1500); + + if (configured) + kgdb_unregister_io_module(&kgdbts_io_ops); + configured = 0; + + return 0; +} + +/* This is noinline such that it can be used for a single location to + * place a breakpoint + */ +static noinline void kgdbts_break_test(void) +{ + v2printk("kgdbts: breakpoint complete\n"); +} + +/* Lookup symbol info in the kernel */ +static unsigned long lookup_addr(char *arg) +{ + unsigned long addr = 0; + + if (!strcmp(arg, "kgdbts_break_test")) + addr = (unsigned long)kgdbts_break_test; + else if (!strcmp(arg, "sys_open")) + addr = (unsigned long)sys_open; + else if (!strcmp(arg, "do_fork")) + addr = (unsigned long)do_fork; + else if (!strcmp(arg, "hw_break_val")) + addr = (unsigned long)&hw_break_val; + return addr; +} + +static void break_helper(char *bp_type, char *arg, unsigned long vaddr) +{ + unsigned long addr; + + if (arg) + addr = lookup_addr(arg); + else + addr = vaddr; + + sprintf(scratch_buf, "%s,%lx,%i", bp_type, addr, + BREAK_INSTR_SIZE); + fill_get_buf(scratch_buf); +} + +static void sw_break(char *arg) +{ + break_helper("Z0", arg, 0); +} + +static void sw_rem_break(char *arg) +{ + break_helper("z0", arg, 0); +} + +static void hw_break(char *arg) +{ + break_helper("Z1", arg, 0); +} + +static void hw_rem_break(char *arg) +{ + break_helper("z1", arg, 0); +} + +static void hw_write_break(char *arg) +{ + break_helper("Z2", arg, 0); +} + +static void hw_rem_write_break(char *arg) +{ + break_helper("z2", arg, 0); +} + +static void hw_access_break(char *arg) +{ + break_helper("Z4", arg, 0); +} + +static void hw_rem_access_break(char *arg) +{ + break_helper("z4", arg, 0); +} + +static void hw_break_val_access(void) +{ + hw_break_val2 = hw_break_val; +} + +static void hw_break_val_write(void) +{ + hw_break_val++; +} + +static int check_and_rewind_pc(char *put_str, char *arg) +{ + unsigned long addr = lookup_addr(arg); + int offset = 0; + + kgdb_hex2mem(&put_str[1], (char *)kgdbts_gdb_regs, + NUMREGBYTES); + gdb_regs_to_pt_regs(kgdbts_gdb_regs, &kgdbts_regs); + v2printk("Stopped at IP: %lx\n", instruction_pointer(&kgdbts_regs)); +#ifdef CONFIG_X86 + /* On x86 a breakpoint stop requires it to be decremented */ + if (addr + 1 == kgdbts_regs.ip) + offset = -1; +#endif + if (strcmp(arg, "silent") && + instruction_pointer(&kgdbts_regs) + offset != addr) { + eprintk("kgdbts: BP mismatch %lx expected %lx\n", + instruction_pointer(&kgdbts_regs) + offset, addr); + return 1; + } +#ifdef CONFIG_X86 + /* On x86 adjust the instruction pointer if needed */ + kgdbts_regs.ip += offset; +#endif + return 0; +} + +static int check_single_step(char *put_str, char *arg) +{ + unsigned long addr = lookup_addr(arg); + /* + * From an arch indepent point of view the instruction pointer + * should be on a different instruction + */ + kgdb_hex2mem(&put_str[1], (char *)kgdbts_gdb_regs, + NUMREGBYTES); + gdb_regs_to_pt_regs(kgdbts_gdb_regs, &kgdbts_regs); + v2printk("Singlestep stopped at IP: %lx\n", + instruction_pointer(&kgdbts_regs)); + if (instruction_pointer(&kgdbts_regs) == addr) { + eprintk("kgdbts: SingleStep failed at %lx\n", + instruction_pointer(&kgdbts_regs)); + return 1; + } + + return 0; +} + +static void write_regs(char *arg) +{ + memset(scratch_buf, 0, sizeof(scratch_buf)); + scratch_buf[0] = 'G'; + pt_regs_to_gdb_regs(kgdbts_gdb_regs, &kgdbts_regs); + kgdb_mem2hex((char *)kgdbts_gdb_regs, &scratch_buf[1], NUMREGBYTES); + fill_get_buf(scratch_buf); +} + +static void skip_back_repeat_test(char *arg) +{ + int go_back = simple_strtol(arg, NULL, 10); + + repeat_test--; + if (repeat_test <= 0) + ts.idx++; + else + ts.idx -= go_back; + fill_get_buf(ts.tst[ts.idx].get); +} + +static int got_break(char *put_str, char *arg) +{ + test_complete = 1; + if (!strncmp(put_str+1, arg, 2)) { + if (!strncmp(arg, "T0", 2)) + test_complete = 2; + return 0; + } + return 1; +} + +static void emul_sstep_get(char *arg) +{ + if (!arch_needs_sstep_emulation) { + fill_get_buf(arg); + return; + } + switch (sstep_state) { + case 0: + v2printk("Emulate single step\n"); + /* Start by looking at the current PC */ + fill_get_buf("g"); + break; + case 1: + /* set breakpoint */ + break_helper("Z0", 0, sstep_addr); + break; + case 2: + /* Continue */ + fill_get_buf("c"); + break; + case 3: + /* Clear breakpoint */ + break_helper("z0", 0, sstep_addr); + break; + default: + eprintk("kgdbts: ERROR failed sstep get emulation\n"); + } + sstep_state++; +} + +static int emul_sstep_put(char *put_str, char *arg) +{ + if (!arch_needs_sstep_emulation) { + if (!strncmp(put_str+1, arg, 2)) + return 0; + return 1; + } + switch (sstep_state) { + case 1: + /* validate the "g" packet to get the IP */ + kgdb_hex2mem(&put_str[1], (char *)kgdbts_gdb_regs, + NUMREGBYTES); + gdb_regs_to_pt_regs(kgdbts_gdb_regs, &kgdbts_regs); + v2printk("Stopped at IP: %lx\n", + instruction_pointer(&kgdbts_regs)); + /* Want to stop at IP + break instruction size by default */ + sstep_addr = instruction_pointer(&kgdbts_regs) + + BREAK_INSTR_SIZE; + break; + case 2: + if (strncmp(put_str, "$OK", 3)) { + eprintk("kgdbts: failed sstep break set\n"); + return 1; + } + break; + case 3: + if (strncmp(put_str, "$T0", 3)) { + eprintk("kgdbts: failed continue sstep\n"); + return 1; + } + break; + case 4: + if (strncmp(put_str, "$OK", 3)) { + eprintk("kgdbts: failed sstep break unset\n"); + return 1; + } + /* Single step is complete so continue on! */ + sstep_state = 0; + return 0; + default: + eprintk("kgdbts: ERROR failed sstep put emulation\n"); + } + + /* Continue on the same test line until emulation is complete */ + ts.idx--; + return 0; +} + +static int final_ack_set(char *put_str, char *arg) +{ + if (strncmp(put_str+1, arg, 2)) + return 1; + final_ack = 1; + return 0; +} +/* + * Test to plant a breakpoint and detach, which should clear out the + * breakpoint and restore the original instruction. + */ +static struct test_struct plant_and_detach_test[] = { + { "?", "S0*" }, /* Clear break points */ + { "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */ + { "D", "OK" }, /* Detach */ + { "", "" }, +}; + +/* + * Simple test to write in a software breakpoint, check for the + * correct stop location and detach. + */ +static struct test_struct sw_breakpoint_test[] = { + { "?", "S0*" }, /* Clear break points */ + { "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */ + { "c", "T0*", }, /* Continue */ + { "g", "kgdbts_break_test", 0, check_and_rewind_pc }, + { "write", "OK", write_regs }, + { "kgdbts_break_test", "OK", sw_rem_break }, /*remove breakpoint */ + { "D", "OK" }, /* Detach */ + { "D", "OK", 0, got_break }, /* If the test worked we made it here */ + { "", "" }, +}; + +/* + * Test a known bad memory read location to test the fault handler and + * read bytes 1-8 at the bad address + */ +static struct test_struct bad_read_test[] = { + { "?", "S0*" }, /* Clear break points */ + { "m0,1", "E*" }, /* read 1 byte at address 1 */ + { "m0,2", "E*" }, /* read 1 byte at address 2 */ + { "m0,3", "E*" }, /* read 1 byte at address 3 */ + { "m0,4", "E*" }, /* read 1 byte at address 4 */ + { "m0,5", "E*" }, /* read 1 byte at address 5 */ + { "m0,6", "E*" }, /* read 1 byte at address 6 */ + { "m0,7", "E*" }, /* read 1 byte at address 7 */ + { "m0,8", "E*" }, /* read 1 byte at address 8 */ + { "D", "OK" }, /* Detach which removes all breakpoints and continues */ + { "", "" }, +}; + +/* + * Test for hitting a breakpoint, remove it, single step, plant it + * again and detach. + */ +static struct test_struct singlestep_break_test[] = { + { "?", "S0*" }, /* Clear break points */ + { "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */ + { "c", "T0*", }, /* Continue */ + { "g", "kgdbts_break_test", 0, check_and_rewind_pc }, + { "write", "OK", write_regs }, /* Write registers */ + { "kgdbts_break_test", "OK", sw_rem_break }, /*remove breakpoint */ + { "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */ + { "g", "kgdbts_break_test", 0, check_single_step }, + { "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */ + { "c", "T0*", }, /* Continue */ + { "g", "kgdbts_break_test", 0, check_and_rewind_pc }, + { "write", "OK", write_regs }, /* Write registers */ + { "D", "OK" }, /* Remove all breakpoints and continues */ + { "", "" }, +}; + +/* + * Test for hitting a breakpoint at do_fork for what ever the number + * of iterations required by the variable repeat_test. + */ +static struct test_struct do_fork_test[] = { + { "?", "S0*" }, /* Clear break points */ + { "do_fork", "OK", sw_break, }, /* set sw breakpoint */ + { "c", "T0*", }, /* Continue */ + { "g", "do_fork", 0, check_and_rewind_pc }, /* check location */ + { "write", "OK", write_regs }, /* Write registers */ + { "do_fork", "OK", sw_rem_break }, /*remove breakpoint */ + { "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */ + { "g", "do_fork", 0, check_single_step }, + { "do_fork", "OK", sw_break, }, /* set sw breakpoint */ + { "7", "T0*", skip_back_repeat_test }, /* Loop based on repeat_test */ + { "D", "OK", 0, final_ack_set }, /* detach and unregister I/O */ + { "", "" }, +}; + +/* Test for hitting a breakpoint at sys_open for what ever the number + * of iterations required by the variable repeat_test. + */ +static struct test_struct sys_open_test[] = { + { "?", "S0*" }, /* Clear break points */ + { "sys_open", "OK", sw_break, }, /* set sw breakpoint */ + { "c", "T0*", }, /* Continue */ + { "g", "sys_open", 0, check_and_rewind_pc }, /* check location */ + { "write", "OK", write_regs }, /* Write registers */ + { "sys_open", "OK", sw_rem_break }, /*remove breakpoint */ + { "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */ + { "g", "sys_open", 0, check_single_step }, + { "sys_open", "OK", sw_break, }, /* set sw breakpoint */ + { "7", "T0*", skip_back_repeat_test }, /* Loop based on repeat_test */ + { "D", "OK", 0, final_ack_set }, /* detach and unregister I/O */ + { "", "" }, +}; + +/* + * Test for hitting a simple hw breakpoint + */ +static struct test_struct hw_breakpoint_test[] = { + { "?", "S0*" }, /* Clear break points */ + { "kgdbts_break_test", "OK", hw_break, }, /* set hw breakpoint */ + { "c", "T0*", }, /* Continue */ + { "g", "kgdbts_break_test", 0, check_and_rewind_pc }, + { "write", "OK", write_regs }, + { "kgdbts_break_test", "OK", hw_rem_break }, /*remove breakpoint */ + { "D", "OK" }, /* Detach */ + { "D", "OK", 0, got_break }, /* If the test worked we made it here */ + { "", "" }, +}; + +/* + * Test for hitting a hw write breakpoint + */ +static struct test_struct hw_write_break_test[] = { + { "?", "S0*" }, /* Clear break points */ + { "hw_break_val", "OK", hw_write_break, }, /* set hw breakpoint */ + { "c", "T0*", 0, got_break }, /* Continue */ + { "g", "silent", 0, check_and_rewind_pc }, + { "write", "OK", write_regs }, + { "hw_break_val", "OK", hw_rem_write_break }, /*remove breakpoint */ + { "D", "OK" }, /* Detach */ + { "D", "OK", 0, got_break }, /* If the test worked we made it here */ + { "", "" }, +}; + +/* + * Test for hitting a hw access breakpoint + */ +static struct test_struct hw_access_break_test[] = { + { "?", "S0*" }, /* Clear break points */ + { "hw_break_val", "OK", hw_access_break, }, /* set hw breakpoint */ + { "c", "T0*", 0, got_break }, /* Continue */ + { "g", "silent", 0, check_and_rewind_pc }, + { "write", "OK", write_regs }, + { "hw_break_val", "OK", hw_rem_access_break }, /*remove breakpoint */ + { "D", "OK" }, /* Detach */ + { "D", "OK", 0, got_break }, /* If the test worked we made it here */ + { "", "" }, +}; + +/* + * Test for hitting a hw access breakpoint + */ +static struct test_struct nmi_sleep_test[] = { + { "?", "S0*" }, /* Clear break points */ + { "c", "T0*", 0, got_break }, /* Continue */ + { "D", "OK" }, /* Detach */ + { "D", "OK", 0, got_break }, /* If the test worked we made it here */ + { "", "" }, +}; + +static void fill_get_buf(char *buf) +{ + unsigned char checksum = 0; + int count = 0; + char ch; + + strcpy(get_buf, "$"); + strcat(get_buf, buf); + while ((ch = buf[count])) { + checksum += ch; + count++; + } + strcat(get_buf, "#"); + get_buf[count + 2] = hexchars[checksum >> 4]; + get_buf[count + 3] = hexchars[checksum & 0xf]; + get_buf[count + 4] = '\0'; + v2printk("get%i: %s\n", ts.idx, get_buf); +} + +static int validate_simple_test(char *put_str) +{ + char *chk_str; + + if (ts.tst[ts.idx].put_handler) + return ts.tst[ts.idx].put_handler(put_str, + ts.tst[ts.idx].put); + + chk_str = ts.tst[ts.idx].put; + if (*put_str == '$') + put_str++; + + while (*chk_str != '\0' && *put_str != '\0') { + /* If someone does a * to match the rest of the string, allow + * it, or stop if the recieved string is complete. + */ + if (*put_str == '#' || *chk_str == '*') + return 0; + if (*put_str != *chk_str) + return 1; + + chk_str++; + put_str++; + } + if (*chk_str == '\0' && (*put_str == '\0' || *put_str == '#')) + return 0; + + return 1; +} + +static int run_simple_test(int is_get_char, int chr) +{ + int ret = 0; + if (is_get_char) { + /* Send an ACK on the get if a prior put completed and set the + * send ack variable + */ + if (send_ack) { + send_ack = 0; + return '+'; + } + /* On the first get char, fill the transmit buffer and then + * take from the get_string. + */ + if (get_buf_cnt == 0) { + if (ts.tst[ts.idx].get_handler) + ts.tst[ts.idx].get_handler(ts.tst[ts.idx].get); + else + fill_get_buf(ts.tst[ts.idx].get); + } + + if (get_buf[get_buf_cnt] == '\0') { + eprintk("kgdbts: ERROR GET: EOB on '%s' at %i\n", + ts.name, ts.idx); + get_buf_cnt = 0; + fill_get_buf("D"); + } + ret = get_buf[get_buf_cnt]; + get_buf_cnt++; + return ret; + } + + /* This callback is a put char which is when kgdb sends data to + * this I/O module. + */ + if (ts.tst[ts.idx].get[0] == '\0' && + ts.tst[ts.idx].put[0] == '\0') { + eprintk("kgdbts: ERROR: beyond end of test on" + " '%s' line %i\n", ts.name, ts.idx); + return 0; + } + + if (put_buf_cnt >= BUFMAX) { + eprintk("kgdbts: ERROR: put buffer overflow on" + " '%s' line %i\n", ts.name, ts.idx); + put_buf_cnt = 0; + return 0; + } + /* Ignore everything until the first valid packet start '$' */ + if (put_buf_cnt == 0 && chr != '$') + return 0; + + put_buf[put_buf_cnt] = chr; + put_buf_cnt++; + + /* End of packet == #XX so look for the '#' */ + if (put_buf_cnt > 3 && put_buf[put_buf_cnt - 3] == '#') { + put_buf[put_buf_cnt] = '\0'; + v2printk("put%i: %s\n", ts.idx, put_buf); + /* Trigger check here */ + if (ts.validate_put && ts.validate_put(put_buf)) { + eprintk("kgdbts: ERROR PUT: end of test " + "buffer on '%s' line %i expected %s got %s\n", + ts.name, ts.idx, ts.tst[ts.idx].put, put_buf); + } + ts.idx++; + put_buf_cnt = 0; + get_buf_cnt = 0; + send_ack = 1; + } + return 0; +} + +static void init_simple_test(void) +{ + memset(&ts, 0, sizeof(ts)); + ts.run_test = run_simple_test; + ts.validate_put = validate_simple_test; +} + +static void run_plant_and_detach_test(int is_early) +{ + char before[BREAK_INSTR_SIZE]; + char after[BREAK_INSTR_SIZE]; + + probe_kernel_read(before, (char *)kgdbts_break_test, + BREAK_INSTR_SIZE); + init_simple_test(); + ts.tst = plant_and_detach_test; + ts.name = "plant_and_detach_test"; + /* Activate test with initial breakpoint */ + if (!is_early) + kgdb_breakpoint(); + probe_kernel_read(after, (char *)kgdbts_break_test, + BREAK_INSTR_SIZE); + if (memcmp(before, after, BREAK_INSTR_SIZE)) { + printk(KERN_CRIT "kgdbts: ERROR kgdb corrupted memory\n"); + panic("kgdb memory corruption"); + } + + /* complete the detach test */ + if (!is_early) + kgdbts_break_test(); +} + +static void run_breakpoint_test(int is_hw_breakpoint) +{ + test_complete = 0; + init_simple_test(); + if (is_hw_breakpoint) { + ts.tst = hw_breakpoint_test; + ts.name = "hw_breakpoint_test"; + } else { + ts.tst = sw_breakpoint_test; + ts.name = "sw_breakpoint_test"; + } + /* Activate test with initial breakpoint */ + kgdb_breakpoint(); + /* run code with the break point in it */ + kgdbts_break_test(); + kgdb_breakpoint(); + + if (test_complete) + return; + + eprintk("kgdbts: ERROR %s test failed\n", ts.name); +} + +static void run_hw_break_test(int is_write_test) +{ + test_complete = 0; + init_simple_test(); + if (is_write_test) { + ts.tst = hw_write_break_test; + ts.name = "hw_write_break_test"; + } else { + ts.tst = hw_access_break_test; + ts.name = "hw_access_break_test"; + } + /* Activate test with initial breakpoint */ + kgdb_breakpoint(); + hw_break_val_access(); + if (is_write_test) { + if (test_complete == 2) + eprintk("kgdbts: ERROR %s broke on access\n", + ts.name); + hw_break_val_write(); + } + kgdb_breakpoint(); + + if (test_complete == 1) + return; + + eprintk("kgdbts: ERROR %s test failed\n", ts.name); +} + +static void run_nmi_sleep_test(int nmi_sleep) +{ + unsigned long flags; + + init_simple_test(); + ts.tst = nmi_sleep_test; + ts.name = "nmi_sleep_test"; + /* Activate test with initial breakpoint */ + kgdb_breakpoint(); + local_irq_save(flags); + mdelay(nmi_sleep*1000); + touch_nmi_watchdog(); + local_irq_restore(flags); + if (test_complete != 2) + eprintk("kgdbts: ERROR nmi_test did not hit nmi\n"); + kgdb_breakpoint(); + if (test_complete == 1) + return; + + eprintk("kgdbts: ERROR %s test failed\n", ts.name); +} + +static void run_bad_read_test(void) +{ + init_simple_test(); + ts.tst = bad_read_test; + ts.name = "bad_read_test"; + /* Activate test with initial breakpoint */ + kgdb_breakpoint(); +} + +static void run_do_fork_test(void) +{ + init_simple_test(); + ts.tst = do_fork_test; + ts.name = "do_fork_test"; + /* Activate test with initial breakpoint */ + kgdb_breakpoint(); +} + +static void run_sys_open_test(void) +{ + init_simple_test(); + ts.tst = sys_open_test; + ts.name = "sys_open_test"; + /* Activate test with initial breakpoint */ + kgdb_breakpoint(); +} + +static void run_singlestep_break_test(void) +{ + init_simple_test(); + ts.tst = singlestep_break_test; + ts.name = "singlestep_breakpoint_test"; + /* Activate test with initial breakpoint */ + kgdb_breakpoint(); + kgdbts_break_test(); + kgdbts_break_test(); +} + +static void kgdbts_run_tests(void) +{ + char *ptr; + int fork_test = 0; + int sys_open_test = 0; + int nmi_sleep = 0; + + ptr = strstr(config, "F"); + if (ptr) + fork_test = simple_strtol(ptr+1, NULL, 10); + ptr = strstr(config, "S"); + if (ptr) + sys_open_test = simple_strtol(ptr+1, NULL, 10); + ptr = strstr(config, "N"); + if (ptr) + nmi_sleep = simple_strtol(ptr+1, NULL, 10); + + /* required internal KGDB tests */ + v1printk("kgdbts:RUN plant and detach test\n"); + run_plant_and_detach_test(0); + v1printk("kgdbts:RUN sw breakpoint test\n"); + run_breakpoint_test(0); + v1printk("kgdbts:RUN bad memory access test\n"); + run_bad_read_test(); + v1printk("kgdbts:RUN singlestep breakpoint test\n"); + run_singlestep_break_test(); + + /* ===Optional tests=== */ + + /* All HW break point tests */ + if (arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT) { + v1printk("kgdbts:RUN hw breakpoint test\n"); + run_breakpoint_test(1); + v1printk("kgdbts:RUN hw write breakpoint test\n"); + run_hw_break_test(1); + v1printk("kgdbts:RUN access write breakpoint test\n"); + run_hw_break_test(0); + } + + if (nmi_sleep) { + v1printk("kgdbts:RUN NMI sleep %i seconds test\n", nmi_sleep); + run_nmi_sleep_test(nmi_sleep); + } + + /* If the do_fork test is run it will be the last test that is + * executed because a kernel thread will be spawned at the very + * end to unregister the debug hooks. + */ + if (fork_test) { + repeat_test = fork_test; + printk(KERN_INFO "kgdbts:RUN do_fork for %i breakpoints\n", + repeat_test); + kthread_run(kgdbts_unreg_thread, 0, "kgdbts_unreg"); + run_do_fork_test(); + return; + } + + /* If the sys_open test is run it will be the last test that is + * executed because a kernel thread will be spawned at the very + * end to unregister the debug hooks. + */ + if (sys_open_test) { + repeat_test = sys_open_test; + printk(KERN_INFO "kgdbts:RUN sys_open for %i breakpoints\n", + repeat_test); + kthread_run(kgdbts_unreg_thread, 0, "kgdbts_unreg"); + run_sys_open_test(); + return; + } + /* Shutdown and unregister */ + kgdb_unregister_io_module(&kgdbts_io_ops); + configured = 0; +} + +static int kgdbts_option_setup(char *opt) +{ + if (strlen(opt) > MAX_CONFIG_LEN) { + printk(KERN_ERR "kgdbts: config string too long\n"); + return -ENOSPC; + } + strcpy(config, opt); + + verbose = 0; + if (strstr(config, "V1")) + verbose = 1; + if (strstr(config, "V2")) + verbose = 2; + + return 0; +} + +__setup("kgdbts=", kgdbts_option_setup); + +static int configure_kgdbts(void) +{ + int err = 0; + + if (!strlen(config) || isspace(config[0])) + goto noconfig; + err = kgdbts_option_setup(config); + if (err) + goto noconfig; + + final_ack = 0; + run_plant_and_detach_test(1); + + err = kgdb_register_io_module(&kgdbts_io_ops); + if (err) { + configured = 0; + return err; + } + configured = 1; + kgdbts_run_tests(); + + return err; + +noconfig: + config[0] = 0; + configured = 0; + + return err; +} + +static int __init init_kgdbts(void) +{ + /* Already configured? */ + if (configured == 1) + return 0; + + return configure_kgdbts(); +} + +static void cleanup_kgdbts(void) +{ + if (configured == 1) + kgdb_unregister_io_module(&kgdbts_io_ops); +} + +static int kgdbts_get_char(void) +{ + int val = 0; + + if (ts.run_test) + val = ts.run_test(1, 0); + + return val; +} + +static void kgdbts_put_char(u8 chr) +{ + if (ts.run_test) + ts.run_test(0, chr); +} + +static int param_set_kgdbts_var(const char *kmessage, struct kernel_param *kp) +{ + int len = strlen(kmessage); + + if (len >= MAX_CONFIG_LEN) { + printk(KERN_ERR "kgdbts: config string too long\n"); + return -ENOSPC; + } + + /* Only copy in the string if the init function has not run yet */ + if (configured < 0) { + strcpy(config, kmessage); + return 0; + } + + if (kgdb_connected) { + printk(KERN_ERR + "kgdbts: Cannot reconfigure while KGDB is connected.\n"); + + return -EBUSY; + } + + strcpy(config, kmessage); + /* Chop out \n char as a result of echo */ + if (config[len - 1] == '\n') + config[len - 1] = '\0'; + + if (configured == 1) + cleanup_kgdbts(); + + /* Go and configure with the new params. */ + return configure_kgdbts(); +} + +static void kgdbts_pre_exp_handler(void) +{ + /* Increment the module count when the debugger is active */ + if (!kgdb_connected) + try_module_get(THIS_MODULE); +} + +static void kgdbts_post_exp_handler(void) +{ + /* decrement the module count when the debugger detaches */ + if (!kgdb_connected) + module_put(THIS_MODULE); +} + +static struct kgdb_io kgdbts_io_ops = { + .name = "kgdbts", + .read_char = kgdbts_get_char, + .write_char = kgdbts_put_char, + .pre_exception = kgdbts_pre_exp_handler, + .post_exception = kgdbts_post_exp_handler, +}; + +module_init(init_kgdbts); +module_exit(cleanup_kgdbts); +module_param_call(kgdbts, param_set_kgdbts_var, param_get_string, &kps, 0644); +MODULE_PARM_DESC(kgdbts, "<A|V1|V2>[F#|S#][N#]"); +MODULE_DESCRIPTION("KGDB Test Suite"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Wind River Systems, Inc."); + diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 77f7a7f0646..96a585e1cee 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -1740,6 +1740,60 @@ static inline void wait_for_xmitr(struct uart_8250_port *up, int bits) } } +#ifdef CONFIG_CONSOLE_POLL +/* + * Console polling routines for writing and reading from the uart while + * in an interrupt or debug context. + */ + +static int serial8250_get_poll_char(struct uart_port *port) +{ + struct uart_8250_port *up = (struct uart_8250_port *)port; + unsigned char lsr = serial_inp(up, UART_LSR); + + while (!(lsr & UART_LSR_DR)) + lsr = serial_inp(up, UART_LSR); + + return serial_inp(up, UART_RX); +} + + +static void serial8250_put_poll_char(struct uart_port *port, + unsigned char c) +{ + unsigned int ier; + struct uart_8250_port *up = (struct uart_8250_port *)port; + + /* + * First save the IER then disable the interrupts + */ + ier = serial_in(up, UART_IER); + if (up->capabilities & UART_CAP_UUE) + serial_out(up, UART_IER, UART_IER_UUE); + else + serial_out(up, UART_IER, 0); + + wait_for_xmitr(up, BOTH_EMPTY); + /* + * Send the character out. + * If a LF, also do CR... + */ + serial_out(up, UART_TX, c); + if (c == 10) { + wait_for_xmitr(up, BOTH_EMPTY); + serial_out(up, UART_TX, 13); + } + + /* + * Finally, wait for transmitter to become empty + * and restore the IER + */ + wait_for_xmitr(up, BOTH_EMPTY); + serial_out(up, UART_IER, ier); +} + +#endif /* CONFIG_CONSOLE_POLL */ + static int serial8250_startup(struct uart_port *port) { struct uart_8250_port *up = (struct uart_8250_port *)port; @@ -2386,6 +2440,10 @@ static struct uart_ops serial8250_pops = { .request_port = serial8250_request_port, .config_port = serial8250_config_port, .verify_port = serial8250_verify_port, +#ifdef CONFIG_CONSOLE_POLL + .poll_get_char = serial8250_get_poll_char, + .poll_put_char = serial8250_put_poll_char, +#endif }; static struct uart_8250_port serial8250_ports[UART_NR]; diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index cf627cd1b4c..f7cd9504d81 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -961,6 +961,9 @@ config SERIAL_CORE config SERIAL_CORE_CONSOLE bool +config CONSOLE_POLL + bool + config SERIAL_68328 bool "68328 serial support" depends on M68328 || M68EZ328 || M68VZ328 diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile index 640cfe44a56..3cbea549472 100644 --- a/drivers/serial/Makefile +++ b/drivers/serial/Makefile @@ -66,4 +66,5 @@ obj-$(CONFIG_SERIAL_UARTLITE) += uartlite.o obj-$(CONFIG_SERIAL_NETX) += netx-serial.o obj-$(CONFIG_SERIAL_OF_PLATFORM) += of_serial.o obj-$(CONFIG_SERIAL_KS8695) += serial_ks8695.o +obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o obj-$(CONFIG_SERIAL_QE) += ucc_uart.o diff --git a/drivers/serial/amba-pl011.c b/drivers/serial/amba-pl011.c index 40604a09292..08adc1de4a7 100644 --- a/drivers/serial/amba-pl011.c +++ b/drivers/serial/amba-pl011.c @@ -314,6 +314,32 @@ static void pl011_break_ctl(struct uart_port *port, int break_state) spin_unlock_irqrestore(&uap->port.lock, flags); } +#ifdef CONFIG_CONSOLE_POLL +static int pl010_get_poll_char(struct uart_port *port) +{ + struct uart_amba_port *uap = (struct uart_amba_port *)port; + unsigned int status; + + do { + status = readw(uap->port.membase + UART01x_FR); + } while (status & UART01x_FR_RXFE); + + return readw(uap->port.membase + UART01x_DR); +} + +static void pl010_put_poll_char(struct uart_port *port, + unsigned char ch) +{ + struct uart_amba_port *uap = (struct uart_amba_port *)port; + + while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_TXFF) + barrier(); + + writew(ch, uap->port.membase + UART01x_DR); +} + +#endif /* CONFIG_CONSOLE_POLL */ + static int pl011_startup(struct uart_port *port) { struct uart_amba_port *uap = (struct uart_amba_port *)port; @@ -572,6 +598,10 @@ static struct uart_ops amba_pl011_pops = { .request_port = pl010_request_port, .config_port = pl010_config_port, .verify_port = pl010_verify_port, +#ifdef CONFIG_CONSOLE_POLL + .poll_get_char = pl010_get_poll_char, + .poll_put_char = pl010_put_poll_char, +#endif }; static struct uart_amba_port *amba_ports[UART_NR]; diff --git a/drivers/serial/kgdboc.c b/drivers/serial/kgdboc.c new file mode 100644 index 00000000000..9cf03327386 --- /dev/null +++ b/drivers/serial/kgdboc.c @@ -0,0 +1,168 @@ +/* + * Based on the same principle as kgdboe using the NETPOLL api, this + * driver uses a console polling api to implement a gdb serial inteface + * which is multiplexed on a console port. + * + * Maintainer: Jason Wessel <jason.wessel@windriver.com> + * + * 2007-2008 (c) Jason Wessel - Wind River Systems, Inc. + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ +#include <linux/kernel.h> +#include <linux/ctype.h> +#include <linux/kgdb.h> +#include <linux/tty.h> + +#define MAX_CONFIG_LEN 40 + +static struct kgdb_io kgdboc_io_ops; + +/* -1 = init not run yet, 0 = unconfigured, 1 = configured. */ +static int configured = -1; + +static char config[MAX_CONFIG_LEN]; +static struct kparam_string kps = { + .string = config, + .maxlen = MAX_CONFIG_LEN, +}; + +static struct tty_driver *kgdb_tty_driver; +static int kgdb_tty_line; + +static int kgdboc_option_setup(char *opt) +{ + if (strlen(opt) > MAX_CONFIG_LEN) { + printk(KERN_ERR "kgdboc: config string too long\n"); + return -ENOSPC; + } + strcpy(config, opt); + + return 0; +} + +__setup("kgdboc=", kgdboc_option_setup); + +static int configure_kgdboc(void) +{ + struct tty_driver *p; + int tty_line = 0; + int err; + + err = kgdboc_option_setup(config); + if (err || !strlen(config) || isspace(config[0])) + goto noconfig; + + err = -ENODEV; + + p = tty_find_polling_driver(config, &tty_line); + if (!p) + goto noconfig; + + kgdb_tty_driver = p; + kgdb_tty_line = tty_line; + + err = kgdb_register_io_module(&kgdboc_io_ops); + if (err) + goto noconfig; + + configured = 1; + + return 0; + +noconfig: + config[0] = 0; + configured = 0; + + return err; +} + +static int __init init_kgdboc(void) +{ + /* Already configured? */ + if (configured == 1) + return 0; + + return configure_kgdboc(); +} + +static void cleanup_kgdboc(void) +{ + if (configured == 1) + kgdb_unregister_io_module(&kgdboc_io_ops); +} + +static int kgdboc_get_char(void) +{ + return kgdb_tty_driver->poll_get_char(kgdb_tty_driver, kgdb_tty_line); +} + +static void kgdboc_put_char(u8 chr) +{ + kgdb_tty_driver->poll_put_char(kgdb_tty_driver, kgdb_tty_line, chr); +} + +static int param_set_kgdboc_var(const char *kmessage, struct kernel_param *kp) +{ + int len = strlen(kmessage); + + if (len >= MAX_CONFIG_LEN) { + printk(KERN_ERR "kgdboc: config string too long\n"); + return -ENOSPC; + } + + /* Only copy in the string if the init function has not run yet */ + if (configured < 0) { + strcpy(config, kmessage); + return 0; + } + + if (kgdb_connected) { + printk(KERN_ERR + "kgdboc: Cannot reconfigure while KGDB is connected.\n"); + + return -EBUSY; + } + + strcpy(config, kmessage); + /* Chop out \n char as a result of echo */ + if (config[len - 1] == '\n') + config[len - 1] = '\0'; + + if (configured == 1) + cleanup_kgdboc(); + + /* Go and configure with the new params. */ + return configure_kgdboc(); +} + +static void kgdboc_pre_exp_handler(void) +{ + /* Increment the module count when the debugger is active */ + if (!kgdb_connected) + try_module_get(THIS_MODULE); +} + +static void kgdboc_post_exp_handler(void) +{ + /* decrement the module count when the debugger detaches */ + if (!kgdb_connected) + module_put(THIS_MODULE); +} + +static struct kgdb_io kgdboc_io_ops = { + .name = "kgdboc", + .read_char = kgdboc_get_char, + .write_char = kgdboc_put_char, + .pre_exception = kgdboc_pre_exp_handler, + .post_exception = kgdboc_post_exp_handler, +}; + +module_init(init_kgdboc); +module_exit(cleanup_kgdboc); +module_param_call(kgdboc, param_set_kgdboc_var, param_get_string, &kps, 0644); +MODULE_PARM_DESC(kgdboc, "<serial_device>[,baud]"); +MODULE_DESCRIPTION("KGDB Console TTY Driver"); +MODULE_LICENSE("GPL"); diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c index 0f5a17987cc..c32c1ca75f6 100644 --- a/drivers/serial/serial_core.c +++ b/drivers/serial/serial_core.c @@ -1771,7 +1771,7 @@ static int uart_read_proc(char *page, char **start, off_t off, } #endif -#ifdef CONFIG_SERIAL_CORE_CONSOLE +#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL) /* * uart_console_write - write a console message to a serial port * @port: the port to write the message @@ -1827,7 +1827,7 @@ uart_get_console(struct uart_port *ports, int nr, struct console *co) * options. The format of the string is <baud><parity><bits><flow>, * eg: 115200n8r */ -void __init +void uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow) { char *s = options; @@ -1842,6 +1842,7 @@ uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow) if (*s) *flow = *s; } +EXPORT_SYMBOL_GPL(uart_parse_options); struct baud_rates { unsigned int rate; @@ -1872,7 +1873,7 @@ static const struct baud_rates baud_rates[] = { * @bits: number of data bits * @flow: flow control character - 'r' (rts) */ -int __init +int uart_set_options(struct uart_port *port, struct console *co, int baud, int parity, int bits, int flow) { @@ -1924,10 +1925,16 @@ uart_set_options(struct uart_port *port, struct console *co, port->mctrl |= TIOCM_DTR; port->ops->set_termios(port, &termios, &dummy); - co->cflag = termios.c_cflag; + /* + * Allow the setting of the UART parameters with a NULL console + * too: + */ + if (co) + co->cflag = termios.c_cflag; return 0; } +EXPORT_SYMBOL_GPL(uart_set_options); #endif /* CONFIG_SERIAL_CORE_CONSOLE */ static void uart_change_pm(struct uart_state *state, int pm_state) @@ -2182,6 +2189,60 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state, } } +#ifdef CONFIG_CONSOLE_POLL + +static int uart_poll_init(struct tty_driver *driver, int line, char *options) +{ + struct uart_driver *drv = driver->driver_state; + struct uart_state *state = drv->state + line; + struct uart_port *port; + int baud = 9600; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + if (!state || !state->port) + return -1; + + port = state->port; + if (!(port->ops->poll_get_char && port->ops->poll_put_char)) + return -1; + + if (options) { + uart_parse_options(options, &baud, &parity, &bits, &flow); + return uart_set_options(port, NULL, baud, parity, bits, flow); + } + + return 0; +} + +static int uart_poll_get_char(struct tty_driver *driver, int line) +{ + struct uart_driver *drv = driver->driver_state; + struct uart_state *state = drv->state + line; + struct uart_port *port; + + if (!state || !state->port) + return -1; + + port = state->port; + return port->ops->poll_get_char(port); +} + +static void uart_poll_put_char(struct tty_driver *driver, int line, char ch) +{ + struct uart_driver *drv = driver->driver_state; + struct uart_state *state = drv->state + line; + struct uart_port *port; + + if (!state || !state->port) + return; + + port = state->port; + port->ops->poll_put_char(port, ch); +} +#endif + static const struct tty_operations uart_ops = { .open = uart_open, .close = uart_close, @@ -2206,6 +2267,11 @@ static const struct tty_operations uart_ops = { #endif .tiocmget = uart_tiocmget, .tiocmset = uart_tiocmset, +#ifdef CONFIG_CONSOLE_POLL + .poll_init = uart_poll_init, + .poll_get_char = uart_poll_get_char, + .poll_put_char = uart_poll_put_char, +#endif }; /** diff --git a/include/asm-x86/kdebug.h b/include/asm-x86/kdebug.h index 0c4175390da..96651bb59ba 100644 --- a/include/asm-x86/kdebug.h +++ b/include/asm-x86/kdebug.h @@ -20,6 +20,7 @@ enum die_val { DIE_CALL, DIE_NMI_IPI, DIE_PAGE_FAULT, + DIE_NMIUNKNOWN, }; extern void printk_address(unsigned long address, int reliable); diff --git a/include/asm-x86/kgdb.h b/include/asm-x86/kgdb.h new file mode 100644 index 00000000000..484c47554f3 --- /dev/null +++ b/include/asm-x86/kgdb.h @@ -0,0 +1,81 @@ +#ifndef _ASM_KGDB_H_ +#define _ASM_KGDB_H_ + +/* + * Copyright (C) 2001-2004 Amit S. Kale + * Copyright (C) 2008 Wind River Systems, Inc. + */ + +/* + * BUFMAX defines the maximum number of characters in inbound/outbound + * buffers at least NUMREGBYTES*2 are needed for register packets + * Longer buffer is needed to list all threads + */ +#define BUFMAX 1024 + +/* + * Note that this register image is in a different order than + * the register image that Linux produces at interrupt time. + * + * Linux's register image is defined by struct pt_regs in ptrace.h. + * Just why GDB uses a different order is a historical mystery. + */ +#ifdef CONFIG_X86_32 +enum regnames { + GDB_AX, /* 0 */ + GDB_CX, /* 1 */ + GDB_DX, /* 2 */ + GDB_BX, /* 3 */ + GDB_SP, /* 4 */ + GDB_BP, /* 5 */ + GDB_SI, /* 6 */ + GDB_DI, /* 7 */ + GDB_PC, /* 8 also known as eip */ + GDB_PS, /* 9 also known as eflags */ + GDB_CS, /* 10 */ + GDB_SS, /* 11 */ + GDB_DS, /* 12 */ + GDB_ES, /* 13 */ + GDB_FS, /* 14 */ + GDB_GS, /* 15 */ +}; +#else /* ! CONFIG_X86_32 */ +enum regnames { + GDB_AX, /* 0 */ + GDB_DX, /* 1 */ + GDB_CX, /* 2 */ + GDB_BX, /* 3 */ + GDB_SI, /* 4 */ + GDB_DI, /* 5 */ + GDB_BP, /* 6 */ + GDB_SP, /* 7 */ + GDB_R8, /* 8 */ + GDB_R9, /* 9 */ + GDB_R10, /* 10 */ + GDB_R11, /* 11 */ + GDB_R12, /* 12 */ + GDB_R13, /* 13 */ + GDB_R14, /* 14 */ + GDB_R15, /* 15 */ + GDB_PC, /* 16 */ + GDB_PS, /* 17 */ +}; +#endif /* CONFIG_X86_32 */ + +/* + * Number of bytes of registers: + */ +#ifdef CONFIG_X86_32 +# define NUMREGBYTES 64 +#else +# define NUMREGBYTES ((GDB_PS+1)*8) +#endif + +static inline void arch_kgdb_breakpoint(void) +{ + asm(" int $3"); +} +#define BREAK_INSTR_SIZE 1 +#define CACHE_FLUSH_IS_SAFE 1 + +#endif /* _ASM_KGDB_H_ */ diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 85778a4b120..35094479ca5 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -216,6 +216,7 @@ static inline void clocksource_calculate_interval(struct clocksource *c, /* used to install a new clocksource */ extern int clocksource_register(struct clocksource*); extern void clocksource_unregister(struct clocksource*); +extern void clocksource_touch_watchdog(void); extern struct clocksource* clocksource_get_next(void); extern void clocksource_change_rating(struct clocksource *cs, int rating); extern void clocksource_resume(void); diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h new file mode 100644 index 00000000000..9757b1a6d9d --- /dev/null +++ b/include/linux/kgdb.h @@ -0,0 +1,281 @@ +/* + * This provides the callbacks and functions that KGDB needs to share between + * the core, I/O and arch-specific portions. + * + * Author: Amit Kale <amitkale@linsyssoft.com> and + * Tom Rini <trini@kernel.crashing.org> + * + * 2001-2004 (c) Amit S. Kale and 2003-2005 (c) MontaVista Software, Inc. + * This file is licensed under the terms of the GNU General Public License + * version 2. This program is licensed "as is" without any warranty of any + * kind, whether express or implied. + */ +#ifndef _KGDB_H_ +#define _KGDB_H_ + +#include <linux/serial_8250.h> +#include <linux/linkage.h> +#include <linux/init.h> + +#include <asm/atomic.h> +#include <asm/kgdb.h> + +struct pt_regs; + +/** + * kgdb_skipexception - (optional) exit kgdb_handle_exception early + * @exception: Exception vector number + * @regs: Current &struct pt_regs. + * + * On some architectures it is required to skip a breakpoint + * exception when it occurs after a breakpoint has been removed. + * This can be implemented in the architecture specific portion of + * for kgdb. + */ +extern int kgdb_skipexception(int exception, struct pt_regs *regs); + +/** + * kgdb_post_primary_code - (optional) Save error vector/code numbers. + * @regs: Original pt_regs. + * @e_vector: Original error vector. + * @err_code: Original error code. + * + * This is usually needed on architectures which support SMP and + * KGDB. This function is called after all the secondary cpus have + * been put to a know spin state and the primary CPU has control over + * KGDB. + */ +extern void kgdb_post_primary_code(struct pt_regs *regs, int e_vector, + int err_code); + +/** + * kgdb_disable_hw_debug - (optional) Disable hardware debugging hook + * @regs: Current &struct pt_regs. + * + * This function will be called if the particular architecture must + * disable hardware debugging while it is processing gdb packets or + * handling exception. + */ +extern void kgdb_disable_hw_debug(struct pt_regs *regs); + +struct tasklet_struct; +struct task_struct; +struct uart_port; + +/** + * kgdb_breakpoint - compiled in breakpoint + * + * This will be impelmented a static inline per architecture. This + * function is called by the kgdb core to execute an architecture + * specific trap to cause kgdb to enter the exception processing. + * + */ +void kgdb_breakpoint(void); + +extern int kgdb_connected; + +extern atomic_t kgdb_setting_breakpoint; +extern atomic_t kgdb_cpu_doing_single_step; + +extern struct task_struct *kgdb_usethread; +extern struct task_struct *kgdb_contthread; + +enum kgdb_bptype { + BP_BREAKPOINT = 0, + BP_HARDWARE_BREAKPOINT, + BP_WRITE_WATCHPOINT, + BP_READ_WATCHPOINT, + BP_ACCESS_WATCHPOINT +}; + +enum kgdb_bpstate { + BP_UNDEFINED = 0, + BP_REMOVED, + BP_SET, + BP_ACTIVE +}; + +struct kgdb_bkpt { + unsigned long bpt_addr; + unsigned char saved_instr[BREAK_INSTR_SIZE]; + enum kgdb_bptype type; + enum kgdb_bpstate state; +}; + +#ifndef KGDB_MAX_BREAKPOINTS +# define KGDB_MAX_BREAKPOINTS 1000 +#endif + +#define KGDB_HW_BREAKPOINT 1 + +/* + * Functions each KGDB-supporting architecture must provide: + */ + +/** + * kgdb_arch_init - Perform any architecture specific initalization. + * + * This function will handle the initalization of any architecture + * specific callbacks. + */ +extern int kgdb_arch_init(void); + +/** + * kgdb_arch_exit - Perform any architecture specific uninitalization. + * + * This function will handle the uninitalization of any architecture + * specific callbacks, for dynamic registration and unregistration. + */ +extern void kgdb_arch_exit(void); + +/** + * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs + * @gdb_regs: A pointer to hold the registers in the order GDB wants. + * @regs: The &struct pt_regs of the current process. + * + * Convert the pt_regs in @regs into the format for registers that + * GDB expects, stored in @gdb_regs. + */ +extern void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs); + +/** + * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs + * @gdb_regs: A pointer to hold the registers in the order GDB wants. + * @p: The &struct task_struct of the desired process. + * + * Convert the register values of the sleeping process in @p to + * the format that GDB expects. + * This function is called when kgdb does not have access to the + * &struct pt_regs and therefore it should fill the gdb registers + * @gdb_regs with what has been saved in &struct thread_struct + * thread field during switch_to. + */ +extern void +sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p); + +/** + * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs. + * @gdb_regs: A pointer to hold the registers we've received from GDB. + * @regs: A pointer to a &struct pt_regs to hold these values in. + * + * Convert the GDB regs in @gdb_regs into the pt_regs, and store them + * in @regs. + */ +extern void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs); + +/** + * kgdb_arch_handle_exception - Handle architecture specific GDB packets. + * @vector: The error vector of the exception that happened. + * @signo: The signal number of the exception that happened. + * @err_code: The error code of the exception that happened. + * @remcom_in_buffer: The buffer of the packet we have read. + * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into. + * @regs: The &struct pt_regs of the current process. + * + * This function MUST handle the 'c' and 's' command packets, + * as well packets to set / remove a hardware breakpoint, if used. + * If there are additional packets which the hardware needs to handle, + * they are handled here. The code should return -1 if it wants to + * process more packets, and a %0 or %1 if it wants to exit from the + * kgdb callback. + */ +extern int +kgdb_arch_handle_exception(int vector, int signo, int err_code, + char *remcom_in_buffer, + char *remcom_out_buffer, + struct pt_regs *regs); + +/** + * kgdb_roundup_cpus - Get other CPUs into a holding pattern + * @flags: Current IRQ state + * + * On SMP systems, we need to get the attention of the other CPUs + * and get them be in a known state. This should do what is needed + * to get the other CPUs to call kgdb_wait(). Note that on some arches, + * the NMI approach is not used for rounding up all the CPUs. For example, + * in case of MIPS, smp_call_function() is used to roundup CPUs. In + * this case, we have to make sure that interrupts are enabled before + * calling smp_call_function(). The argument to this function is + * the flags that will be used when restoring the interrupts. There is + * local_irq_save() call before kgdb_roundup_cpus(). + * + * On non-SMP systems, this is not called. + */ +extern void kgdb_roundup_cpus(unsigned long flags); + +/* Optional functions. */ +extern int kgdb_validate_break_address(unsigned long addr); +extern int kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr); +extern int kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle); + +/** + * struct kgdb_arch - Describe architecture specific values. + * @gdb_bpt_instr: The instruction to trigger a breakpoint. + * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT. + * @set_breakpoint: Allow an architecture to specify how to set a software + * breakpoint. + * @remove_breakpoint: Allow an architecture to specify how to remove a + * software breakpoint. + * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware + * breakpoint. + * @remove_hw_breakpoint: Allow an architecture to specify how to remove a + * hardware breakpoint. + * @remove_all_hw_break: Allow an architecture to specify how to remove all + * hardware breakpoints. + * @correct_hw_break: Allow an architecture to specify how to correct the + * hardware debug registers. + */ +struct kgdb_arch { + unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE]; + unsigned long flags; + + int (*set_breakpoint)(unsigned long, char *); + int (*remove_breakpoint)(unsigned long, char *); + int (*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype); + int (*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype); + void (*remove_all_hw_break)(void); + void (*correct_hw_break)(void); +}; + +/** + * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB. + * @name: Name of the I/O driver. + * @read_char: Pointer to a function that will return one char. + * @write_char: Pointer to a function that will write one char. + * @flush: Pointer to a function that will flush any pending writes. + * @init: Pointer to a function that will initialize the device. + * @pre_exception: Pointer to a function that will do any prep work for + * the I/O driver. + * @post_exception: Pointer to a function that will do any cleanup work + * for the I/O driver. + */ +struct kgdb_io { + const char *name; + int (*read_char) (void); + void (*write_char) (u8); + void (*flush) (void); + int (*init) (void); + void (*pre_exception) (void); + void (*post_exception) (void); +}; + +extern struct kgdb_arch arch_kgdb_ops; + +extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops); +extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops); + +extern int kgdb_hex2long(char **ptr, long *long_val); +extern int kgdb_mem2hex(char *mem, char *buf, int count); +extern int kgdb_hex2mem(char *buf, char *mem, int count); + +extern int kgdb_isremovedbreak(unsigned long addr); + +extern int +kgdb_handle_exception(int ex_vector, int signo, int err_code, + struct pt_regs *regs); +extern int kgdb_nmicallback(int cpu, void *regs); + +extern int kgdb_single_step; +extern atomic_t kgdb_active; + +#endif /* _KGDB_H_ */ diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 289942fc665..7cb094a8245 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -213,6 +213,10 @@ struct uart_ops { void (*config_port)(struct uart_port *, int); int (*verify_port)(struct uart_port *, struct serial_struct *); int (*ioctl)(struct uart_port *, unsigned int, unsigned long); +#ifdef CONFIG_CONSOLE_POLL + void (*poll_put_char)(struct uart_port *, unsigned char); + int (*poll_get_char)(struct uart_port *); +#endif }; #define UART_CONFIG_TYPE (1 << 0) diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h index 85c95cd39bc..21f69aca450 100644 --- a/include/linux/tty_driver.h +++ b/include/linux/tty_driver.h @@ -125,6 +125,7 @@ #include <linux/cdev.h> struct tty_struct; +struct tty_driver; struct tty_operations { int (*open)(struct tty_struct * tty, struct file * filp); @@ -157,6 +158,11 @@ struct tty_operations { int (*tiocmget)(struct tty_struct *tty, struct file *file); int (*tiocmset)(struct tty_struct *tty, struct file *file, unsigned int set, unsigned int clear); +#ifdef CONFIG_CONSOLE_POLL + int (*poll_init)(struct tty_driver *driver, int line, char *options); + int (*poll_get_char)(struct tty_driver *driver, int line); + void (*poll_put_char)(struct tty_driver *driver, int line, char ch); +#endif }; struct tty_driver { @@ -220,6 +226,11 @@ struct tty_driver { int (*tiocmget)(struct tty_struct *tty, struct file *file); int (*tiocmset)(struct tty_struct *tty, struct file *file, unsigned int set, unsigned int clear); +#ifdef CONFIG_CONSOLE_POLL + int (*poll_init)(struct tty_driver *driver, int line, char *options); + int (*poll_get_char)(struct tty_driver *driver, int line); + void (*poll_put_char)(struct tty_driver *driver, int line, char ch); +#endif struct list_head tty_drivers; }; @@ -230,6 +241,7 @@ struct tty_driver *alloc_tty_driver(int lines); void put_tty_driver(struct tty_driver *driver); void tty_set_operations(struct tty_driver *driver, const struct tty_operations *op); +extern struct tty_driver *tty_find_polling_driver(char *name, int *line); /* tty driver magic number */ #define TTY_DRIVER_MAGIC 0x5402 diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index 975c963e578..fec6decfb98 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -84,4 +84,26 @@ static inline unsigned long __copy_from_user_nocache(void *to, ret; \ }) +/* + * probe_kernel_read(): safely attempt to read from a location + * @dst: pointer to the buffer that shall take the data + * @src: address to read from + * @size: size of the data chunk + * + * Safely read from address @src to the buffer at @dst. If a kernel fault + * happens, handle that and return -EFAULT. + */ +extern long probe_kernel_read(void *dst, void *src, size_t size); + +/* + * probe_kernel_write(): safely attempt to write to a location + * @dst: address to write to + * @src: pointer to the data that shall be written + * @size: size of the data chunk + * + * Safely write to address @dst from the buffer at @src. If a kernel fault + * happens, handle that and return -EFAULT. + */ +extern long probe_kernel_write(void *dst, void *src, size_t size); + #endif /* __LINUX_UACCESS_H__ */ diff --git a/kernel/Makefile b/kernel/Makefile index f45c69e6968..6c5f081132a 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -53,6 +53,7 @@ obj-$(CONFIG_AUDIT) += audit.o auditfilter.o obj-$(CONFIG_AUDITSYSCALL) += auditsc.o obj-$(CONFIG_AUDIT_TREE) += audit_tree.o obj-$(CONFIG_KPROBES) += kprobes.o +obj-$(CONFIG_KGDB) += kgdb.o obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o obj-$(CONFIG_GENERIC_HARDIRQS) += irq/ obj-$(CONFIG_SECCOMP) += seccomp.o diff --git a/kernel/kgdb.c b/kernel/kgdb.c new file mode 100644 index 00000000000..1bd0ec1c80b --- /dev/null +++ b/kernel/kgdb.c @@ -0,0 +1,1700 @@ +/* + * KGDB stub. + * + * Maintainer: Jason Wessel <jason.wessel@windriver.com> + * + * Copyright (C) 2000-2001 VERITAS Software Corporation. + * Copyright (C) 2002-2004 Timesys Corporation + * Copyright (C) 2003-2004 Amit S. Kale <amitkale@linsyssoft.com> + * Copyright (C) 2004 Pavel Machek <pavel@suse.cz> + * Copyright (C) 2004-2006 Tom Rini <trini@kernel.crashing.org> + * Copyright (C) 2004-2006 LinSysSoft Technologies Pvt. Ltd. + * Copyright (C) 2005-2008 Wind River Systems, Inc. + * Copyright (C) 2007 MontaVista Software, Inc. + * Copyright (C) 2008 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> + * + * Contributors at various stages not listed above: + * Jason Wessel ( jason.wessel@windriver.com ) + * George Anzinger <george@mvista.com> + * Anurekh Saxena (anurekh.saxena@timesys.com) + * Lake Stevens Instrument Division (Glenn Engel) + * Jim Kingdon, Cygnus Support. + * + * Original KGDB stub: David Grothe <dave@gcom.com>, + * Tigran Aivazian <tigran@sco.com> + * + * This file is licensed under the terms of the GNU General Public License + * version 2. This program is licensed "as is" without any warranty of any + * kind, whether express or implied. + */ +#include <linux/pid_namespace.h> +#include <linux/clocksource.h> +#include <linux/interrupt.h> +#include <linux/spinlock.h> +#include <linux/console.h> +#include <linux/threads.h> +#include <linux/uaccess.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/ptrace.h> +#include <linux/reboot.h> +#include <linux/string.h> +#include <linux/delay.h> +#include <linux/sched.h> +#include <linux/sysrq.h> +#include <linux/init.h> +#include <linux/kgdb.h> +#include <linux/pid.h> +#include <linux/smp.h> +#include <linux/mm.h> + +#include <asm/cacheflush.h> +#include <asm/byteorder.h> +#include <asm/atomic.h> +#include <asm/system.h> + +static int kgdb_break_asap; + +struct kgdb_state { + int ex_vector; + int signo; + int err_code; + int cpu; + int pass_exception; + long threadid; + long kgdb_usethreadid; + struct pt_regs *linux_regs; +}; + +static struct debuggerinfo_struct { + void *debuggerinfo; + struct task_struct *task; +} kgdb_info[NR_CPUS]; + +/** + * kgdb_connected - Is a host GDB connected to us? + */ +int kgdb_connected; +EXPORT_SYMBOL_GPL(kgdb_connected); + +/* All the KGDB handlers are installed */ +static int kgdb_io_module_registered; + +/* Guard for recursive entry */ +static int exception_level; + +static struct kgdb_io *kgdb_io_ops; +static DEFINE_SPINLOCK(kgdb_registration_lock); + +/* kgdb console driver is loaded */ +static int kgdb_con_registered; +/* determine if kgdb console output should be used */ +static int kgdb_use_con; + +static int __init opt_kgdb_con(char *str) +{ + kgdb_use_con = 1; + return 0; +} + +early_param("kgdbcon", opt_kgdb_con); + +module_param(kgdb_use_con, int, 0644); + +/* + * Holds information about breakpoints in a kernel. These breakpoints are + * added and removed by gdb. + */ +static struct kgdb_bkpt kgdb_break[KGDB_MAX_BREAKPOINTS] = { + [0 ... KGDB_MAX_BREAKPOINTS-1] = { .state = BP_UNDEFINED } +}; + +/* + * The CPU# of the active CPU, or -1 if none: + */ +atomic_t kgdb_active = ATOMIC_INIT(-1); + +/* + * We use NR_CPUs not PERCPU, in case kgdb is used to debug early + * bootup code (which might not have percpu set up yet): + */ +static atomic_t passive_cpu_wait[NR_CPUS]; +static atomic_t cpu_in_kgdb[NR_CPUS]; +atomic_t kgdb_setting_breakpoint; + +struct task_struct *kgdb_usethread; +struct task_struct *kgdb_contthread; + +int kgdb_single_step; + +/* Our I/O buffers. */ +static char remcom_in_buffer[BUFMAX]; +static char remcom_out_buffer[BUFMAX]; + +/* Storage for the registers, in GDB format. */ +static unsigned long gdb_regs[(NUMREGBYTES + + sizeof(unsigned long) - 1) / + sizeof(unsigned long)]; + +/* to keep track of the CPU which is doing the single stepping*/ +atomic_t kgdb_cpu_doing_single_step = ATOMIC_INIT(-1); + +/* + * If you are debugging a problem where roundup (the collection of + * all other CPUs) is a problem [this should be extremely rare], + * then use the nokgdbroundup option to avoid roundup. In that case + * the other CPUs might interfere with your debugging context, so + * use this with care: + */ +int kgdb_do_roundup = 1; + +static int __init opt_nokgdbroundup(char *str) +{ + kgdb_do_roundup = 0; + + return 0; +} + +early_param("nokgdbroundup", opt_nokgdbroundup); + +/* + * Finally, some KGDB code :-) + */ + +/* + * Weak aliases for breakpoint management, + * can be overriden by architectures when needed: + */ +int __weak kgdb_validate_break_address(unsigned long addr) +{ + char tmp_variable[BREAK_INSTR_SIZE]; + + return probe_kernel_read(tmp_variable, (char *)addr, BREAK_INSTR_SIZE); +} + +int __weak kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr) +{ + int err; + + err = probe_kernel_read(saved_instr, (char *)addr, BREAK_INSTR_SIZE); + if (err) + return err; + + return probe_kernel_write((char *)addr, arch_kgdb_ops.gdb_bpt_instr, + BREAK_INSTR_SIZE); +} + +int __weak kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle) +{ + return probe_kernel_write((char *)addr, + (char *)bundle, BREAK_INSTR_SIZE); +} + +unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs) +{ + return instruction_pointer(regs); +} + +int __weak kgdb_arch_init(void) +{ + return 0; +} + +int __weak kgdb_skipexception(int exception, struct pt_regs *regs) +{ + return 0; +} + +void __weak +kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code) +{ + return; +} + +/** + * kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb. + * @regs: Current &struct pt_regs. + * + * This function will be called if the particular architecture must + * disable hardware debugging while it is processing gdb packets or + * handling exception. + */ +void __weak kgdb_disable_hw_debug(struct pt_regs *regs) +{ +} + +/* + * GDB remote protocol parser: + */ + +static const char hexchars[] = "0123456789abcdef"; + +static int hex(char ch) +{ + if ((ch >= 'a') && (ch <= 'f')) + return ch - 'a' + 10; + if ((ch >= '0') && (ch <= '9')) + return ch - '0'; + if ((ch >= 'A') && (ch <= 'F')) + return ch - 'A' + 10; + return -1; +} + +/* scan for the sequence $<data>#<checksum> */ +static void get_packet(char *buffer) +{ + unsigned char checksum; + unsigned char xmitcsum; + int count; + char ch; + + do { + /* + * Spin and wait around for the start character, ignore all + * other characters: + */ + while ((ch = (kgdb_io_ops->read_char())) != '$') + /* nothing */; + + kgdb_connected = 1; + checksum = 0; + xmitcsum = -1; + + count = 0; + + /* + * now, read until a # or end of buffer is found: + */ + while (count < (BUFMAX - 1)) { + ch = kgdb_io_ops->read_char(); + if (ch == '#') + break; + checksum = checksum + ch; + buffer[count] = ch; + count = count + 1; + } + buffer[count] = 0; + + if (ch == '#') { + xmitcsum = hex(kgdb_io_ops->read_char()) << 4; + xmitcsum += hex(kgdb_io_ops->read_char()); + + if (checksum != xmitcsum) + /* failed checksum */ + kgdb_io_ops->write_char('-'); + else + /* successful transfer */ + kgdb_io_ops->write_char('+'); + if (kgdb_io_ops->flush) + kgdb_io_ops->flush(); + } + } while (checksum != xmitcsum); +} + +/* + * Send the packet in buffer. + * Check for gdb connection if asked for. + */ +static void put_packet(char *buffer) +{ + unsigned char checksum; + int count; + char ch; + + /* + * $<packet info>#<checksum>. + */ + while (1) { + kgdb_io_ops->write_char('$'); + checksum = 0; + count = 0; + + while ((ch = buffer[count])) { + kgdb_io_ops->write_char(ch); + checksum += ch; + count++; + } + + kgdb_io_ops->write_char('#'); + kgdb_io_ops->write_char(hexchars[checksum >> 4]); + kgdb_io_ops->write_char(hexchars[checksum & 0xf]); + if (kgdb_io_ops->flush) + kgdb_io_ops->flush(); + + /* Now see what we get in reply. */ + ch = kgdb_io_ops->read_char(); + + if (ch == 3) + ch = kgdb_io_ops->read_char(); + + /* If we get an ACK, we are done. */ + if (ch == '+') + return; + + /* + * If we get the start of another packet, this means + * that GDB is attempting to reconnect. We will NAK + * the packet being sent, and stop trying to send this + * packet. + */ + if (ch == '$') { + kgdb_io_ops->write_char('-'); + if (kgdb_io_ops->flush) + kgdb_io_ops->flush(); + return; + } + } +} + +static char *pack_hex_byte(char *pkt, u8 byte) +{ + *pkt++ = hexchars[byte >> 4]; + *pkt++ = hexchars[byte & 0xf]; + + return pkt; +} + +/* + * Convert the memory pointed to by mem into hex, placing result in buf. + * Return a pointer to the last char put in buf (null). May return an error. + */ +int kgdb_mem2hex(char *mem, char *buf, int count) +{ + char *tmp; + int err; + + /* + * We use the upper half of buf as an intermediate buffer for the + * raw memory copy. Hex conversion will work against this one. + */ + tmp = buf + count; + + err = probe_kernel_read(tmp, mem, count); + if (!err) { + while (count > 0) { + buf = pack_hex_byte(buf, *tmp); + tmp++; + count--; + } + + *buf = 0; + } + + return err; +} + +/* + * Copy the binary array pointed to by buf into mem. Fix $, #, and + * 0x7d escaped with 0x7d. Return a pointer to the character after + * the last byte written. + */ +static int kgdb_ebin2mem(char *buf, char *mem, int count) +{ + int err = 0; + char c; + + while (count-- > 0) { + c = *buf++; + if (c == 0x7d) + c = *buf++ ^ 0x20; + + err = probe_kernel_write(mem, &c, 1); + if (err) + break; + + mem++; + } + + return err; +} + +/* + * Convert the hex array pointed to by buf into binary to be placed in mem. + * Return a pointer to the character AFTER the last byte written. + * May return an error. + */ +int kgdb_hex2mem(char *buf, char *mem, int count) +{ + char *tmp_raw; + char *tmp_hex; + + /* + * We use the upper half of buf as an intermediate buffer for the + * raw memory that is converted from hex. + */ + tmp_raw = buf + count * 2; + + tmp_hex = tmp_raw - 1; + while (tmp_hex >= buf) { + tmp_raw--; + *tmp_raw = hex(*tmp_hex--); + *tmp_raw |= hex(*tmp_hex--) << 4; + } + + return probe_kernel_write(mem, tmp_raw, count); +} + +/* + * While we find nice hex chars, build a long_val. + * Return number of chars processed. + */ +int kgdb_hex2long(char **ptr, long *long_val) +{ + int hex_val; + int num = 0; + + *long_val = 0; + + while (**ptr) { + hex_val = hex(**ptr); + if (hex_val < 0) + break; + + *long_val = (*long_val << 4) | hex_val; + num++; + (*ptr)++; + } + + return num; +} + +/* Write memory due to an 'M' or 'X' packet. */ +static int write_mem_msg(int binary) +{ + char *ptr = &remcom_in_buffer[1]; + unsigned long addr; + unsigned long length; + int err; + + if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' && + kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') { + if (binary) + err = kgdb_ebin2mem(ptr, (char *)addr, length); + else + err = kgdb_hex2mem(ptr, (char *)addr, length); + if (err) + return err; + if (CACHE_FLUSH_IS_SAFE) + flush_icache_range(addr, addr + length + 1); + return 0; + } + + return -EINVAL; +} + +static void error_packet(char *pkt, int error) +{ + error = -error; + pkt[0] = 'E'; + pkt[1] = hexchars[(error / 10)]; + pkt[2] = hexchars[(error % 10)]; + pkt[3] = '\0'; +} + +/* + * Thread ID accessors. We represent a flat TID space to GDB, where + * the per CPU idle threads (which under Linux all have PID 0) are + * remapped to negative TIDs. + */ + +#define BUF_THREAD_ID_SIZE 16 + +static char *pack_threadid(char *pkt, unsigned char *id) +{ + char *limit; + + limit = pkt + BUF_THREAD_ID_SIZE; + while (pkt < limit) + pkt = pack_hex_byte(pkt, *id++); + + return pkt; +} + +static void int_to_threadref(unsigned char *id, int value) +{ + unsigned char *scan; + int i = 4; + + scan = (unsigned char *)id; + while (i--) + *scan++ = 0; + *scan++ = (value >> 24) & 0xff; + *scan++ = (value >> 16) & 0xff; + *scan++ = (value >> 8) & 0xff; + *scan++ = (value & 0xff); +} + +static struct task_struct *getthread(struct pt_regs *regs, int tid) +{ + /* + * Non-positive TIDs are remapped idle tasks: + */ + if (tid <= 0) + return idle_task(-tid); + + /* + * find_task_by_pid_ns() does not take the tasklist lock anymore + * but is nicely RCU locked - hence is a pretty resilient + * thing to use: + */ + return find_task_by_pid_ns(tid, &init_pid_ns); +} + +/* + * CPU debug state control: + */ + +#ifdef CONFIG_SMP +static void kgdb_wait(struct pt_regs *regs) +{ + unsigned long flags; + int cpu; + + local_irq_save(flags); + cpu = raw_smp_processor_id(); + kgdb_info[cpu].debuggerinfo = regs; + kgdb_info[cpu].task = current; + /* + * Make sure the above info reaches the primary CPU before + * our cpu_in_kgdb[] flag setting does: + */ + smp_wmb(); + atomic_set(&cpu_in_kgdb[cpu], 1); + + /* Wait till primary CPU is done with debugging */ + while (atomic_read(&passive_cpu_wait[cpu])) + cpu_relax(); + + kgdb_info[cpu].debuggerinfo = NULL; + kgdb_info[cpu].task = NULL; + + /* fix up hardware debug registers on local cpu */ + if (arch_kgdb_ops.correct_hw_break) + arch_kgdb_ops.correct_hw_break(); + + /* Signal the primary CPU that we are done: */ + atomic_set(&cpu_in_kgdb[cpu], 0); + clocksource_touch_watchdog(); + local_irq_restore(flags); +} +#endif + +/* + * Some architectures need cache flushes when we set/clear a + * breakpoint: + */ +static void kgdb_flush_swbreak_addr(unsigned long addr) +{ + if (!CACHE_FLUSH_IS_SAFE) + return; + + if (current->mm && current->mm->mmap_cache) { + flush_cache_range(current->mm->mmap_cache, + addr, addr + BREAK_INSTR_SIZE); + } + /* Force flush instruction cache if it was outside the mm */ + flush_icache_range(addr, addr + BREAK_INSTR_SIZE); +} + +/* + * SW breakpoint management: + */ +static int kgdb_activate_sw_breakpoints(void) +{ + unsigned long addr; + int error = 0; + int i; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if (kgdb_break[i].state != BP_SET) + continue; + + addr = kgdb_break[i].bpt_addr; + error = kgdb_arch_set_breakpoint(addr, + kgdb_break[i].saved_instr); + if (error) + return error; + + kgdb_flush_swbreak_addr(addr); + kgdb_break[i].state = BP_ACTIVE; + } + return 0; +} + +static int kgdb_set_sw_break(unsigned long addr) +{ + int err = kgdb_validate_break_address(addr); + int breakno = -1; + int i; + + if (err) + return err; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if ((kgdb_break[i].state == BP_SET) && + (kgdb_break[i].bpt_addr == addr)) + return -EEXIST; + } + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if (kgdb_break[i].state == BP_REMOVED && + kgdb_break[i].bpt_addr == addr) { + breakno = i; + break; + } + } + + if (breakno == -1) { + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if (kgdb_break[i].state == BP_UNDEFINED) { + breakno = i; + break; + } + } + } + + if (breakno == -1) + return -E2BIG; + + kgdb_break[breakno].state = BP_SET; + kgdb_break[breakno].type = BP_BREAKPOINT; + kgdb_break[breakno].bpt_addr = addr; + + return 0; +} + +static int kgdb_deactivate_sw_breakpoints(void) +{ + unsigned long addr; + int error = 0; + int i; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if (kgdb_break[i].state != BP_ACTIVE) + continue; + addr = kgdb_break[i].bpt_addr; + error = kgdb_arch_remove_breakpoint(addr, + kgdb_break[i].saved_instr); + if (error) + return error; + + kgdb_flush_swbreak_addr(addr); + kgdb_break[i].state = BP_SET; + } + return 0; +} + +static int kgdb_remove_sw_break(unsigned long addr) +{ + int i; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if ((kgdb_break[i].state == BP_SET) && + (kgdb_break[i].bpt_addr == addr)) { + kgdb_break[i].state = BP_REMOVED; + return 0; + } + } + return -ENOENT; +} + +int kgdb_isremovedbreak(unsigned long addr) +{ + int i; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if ((kgdb_break[i].state == BP_REMOVED) && + (kgdb_break[i].bpt_addr == addr)) + return 1; + } + return 0; +} + +int remove_all_break(void) +{ + unsigned long addr; + int error; + int i; + + /* Clear memory breakpoints. */ + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if (kgdb_break[i].state != BP_ACTIVE) + goto setundefined; + addr = kgdb_break[i].bpt_addr; + error = kgdb_arch_remove_breakpoint(addr, + kgdb_break[i].saved_instr); + if (error) + printk(KERN_ERR "KGDB: breakpoint remove failed: %lx\n", + addr); +setundefined: + kgdb_break[i].state = BP_UNDEFINED; + } + + /* Clear hardware breakpoints. */ + if (arch_kgdb_ops.remove_all_hw_break) + arch_kgdb_ops.remove_all_hw_break(); + + return 0; +} + +/* + * Remap normal tasks to their real PID, idle tasks to -1 ... -NR_CPUs: + */ +static inline int shadow_pid(int realpid) +{ + if (realpid) + return realpid; + + return -1-raw_smp_processor_id(); +} + +static char gdbmsgbuf[BUFMAX + 1]; + +static void kgdb_msg_write(const char *s, int len) +{ + char *bufptr; + int wcount; + int i; + + /* 'O'utput */ + gdbmsgbuf[0] = 'O'; + + /* Fill and send buffers... */ + while (len > 0) { + bufptr = gdbmsgbuf + 1; + + /* Calculate how many this time */ + if ((len << 1) > (BUFMAX - 2)) + wcount = (BUFMAX - 2) >> 1; + else + wcount = len; + + /* Pack in hex chars */ + for (i = 0; i < wcount; i++) + bufptr = pack_hex_byte(bufptr, s[i]); + *bufptr = '\0'; + + /* Move up */ + s += wcount; + len -= wcount; + + /* Write packet */ + put_packet(gdbmsgbuf); + } +} + +/* + * Return true if there is a valid kgdb I/O module. Also if no + * debugger is attached a message can be printed to the console about + * waiting for the debugger to attach. + * + * The print_wait argument is only to be true when called from inside + * the core kgdb_handle_exception, because it will wait for the + * debugger to attach. + */ +static int kgdb_io_ready(int print_wait) +{ + if (!kgdb_io_ops) + return 0; + if (kgdb_connected) + return 1; + if (atomic_read(&kgdb_setting_breakpoint)) + return 1; + if (print_wait) + printk(KERN_CRIT "KGDB: Waiting for remote debugger\n"); + return 1; +} + +/* + * All the functions that start with gdb_cmd are the various + * operations to implement the handlers for the gdbserial protocol + * where KGDB is communicating with an external debugger + */ + +/* Handle the '?' status packets */ +static void gdb_cmd_status(struct kgdb_state *ks) +{ + /* + * We know that this packet is only sent + * during initial connect. So to be safe, + * we clear out our breakpoints now in case + * GDB is reconnecting. + */ + remove_all_break(); + + remcom_out_buffer[0] = 'S'; + pack_hex_byte(&remcom_out_buffer[1], ks->signo); +} + +/* Handle the 'g' get registers request */ +static void gdb_cmd_getregs(struct kgdb_state *ks) +{ + struct task_struct *thread; + void *local_debuggerinfo; + int i; + + thread = kgdb_usethread; + if (!thread) { + thread = kgdb_info[ks->cpu].task; + local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo; + } else { + local_debuggerinfo = NULL; + for (i = 0; i < NR_CPUS; i++) { + /* + * Try to find the task on some other + * or possibly this node if we do not + * find the matching task then we try + * to approximate the results. + */ + if (thread == kgdb_info[i].task) + local_debuggerinfo = kgdb_info[i].debuggerinfo; + } + } + + /* + * All threads that don't have debuggerinfo should be + * in __schedule() sleeping, since all other CPUs + * are in kgdb_wait, and thus have debuggerinfo. + */ + if (local_debuggerinfo) { + pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo); + } else { + /* + * Pull stuff saved during switch_to; nothing + * else is accessible (or even particularly + * relevant). + * + * This should be enough for a stack trace. + */ + sleeping_thread_to_gdb_regs(gdb_regs, thread); + } + kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES); +} + +/* Handle the 'G' set registers request */ +static void gdb_cmd_setregs(struct kgdb_state *ks) +{ + kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES); + + if (kgdb_usethread && kgdb_usethread != current) { + error_packet(remcom_out_buffer, -EINVAL); + } else { + gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs); + strcpy(remcom_out_buffer, "OK"); + } +} + +/* Handle the 'm' memory read bytes */ +static void gdb_cmd_memread(struct kgdb_state *ks) +{ + char *ptr = &remcom_in_buffer[1]; + unsigned long length; + unsigned long addr; + int err; + + if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' && + kgdb_hex2long(&ptr, &length) > 0) { + err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length); + if (err) + error_packet(remcom_out_buffer, err); + } else { + error_packet(remcom_out_buffer, -EINVAL); + } +} + +/* Handle the 'M' memory write bytes */ +static void gdb_cmd_memwrite(struct kgdb_state *ks) +{ + int err = write_mem_msg(0); + + if (err) + error_packet(remcom_out_buffer, err); + else + strcpy(remcom_out_buffer, "OK"); +} + +/* Handle the 'X' memory binary write bytes */ +static void gdb_cmd_binwrite(struct kgdb_state *ks) +{ + int err = write_mem_msg(1); + + if (err) + error_packet(remcom_out_buffer, err); + else + strcpy(remcom_out_buffer, "OK"); +} + +/* Handle the 'D' or 'k', detach or kill packets */ +static void gdb_cmd_detachkill(struct kgdb_state *ks) +{ + int error; + + /* The detach case */ + if (remcom_in_buffer[0] == 'D') { + error = remove_all_break(); + if (error < 0) { + error_packet(remcom_out_buffer, error); + } else { + strcpy(remcom_out_buffer, "OK"); + kgdb_connected = 0; + } + put_packet(remcom_out_buffer); + } else { + /* + * Assume the kill case, with no exit code checking, + * trying to force detach the debugger: + */ + remove_all_break(); + kgdb_connected = 0; + } +} + +/* Handle the 'R' reboot packets */ +static int gdb_cmd_reboot(struct kgdb_state *ks) +{ + /* For now, only honor R0 */ + if (strcmp(remcom_in_buffer, "R0") == 0) { + printk(KERN_CRIT "Executing emergency reboot\n"); + strcpy(remcom_out_buffer, "OK"); + put_packet(remcom_out_buffer); + + /* + * Execution should not return from + * machine_emergency_restart() + */ + machine_emergency_restart(); + kgdb_connected = 0; + + return 1; + } + return 0; +} + +/* Handle the 'q' query packets */ +static void gdb_cmd_query(struct kgdb_state *ks) +{ + struct task_struct *thread; + unsigned char thref[8]; + char *ptr; + int i; + + switch (remcom_in_buffer[1]) { + case 's': + case 'f': + if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10)) { + error_packet(remcom_out_buffer, -EINVAL); + break; + } + + if (remcom_in_buffer[1] == 'f') + ks->threadid = 1; + + remcom_out_buffer[0] = 'm'; + ptr = remcom_out_buffer + 1; + + for (i = 0; i < 17; ks->threadid++) { + thread = getthread(ks->linux_regs, ks->threadid); + if (thread) { + int_to_threadref(thref, ks->threadid); + pack_threadid(ptr, thref); + ptr += BUF_THREAD_ID_SIZE; + *(ptr++) = ','; + i++; + } + } + *(--ptr) = '\0'; + break; + + case 'C': + /* Current thread id */ + strcpy(remcom_out_buffer, "QC"); + ks->threadid = shadow_pid(current->pid); + int_to_threadref(thref, ks->threadid); + pack_threadid(remcom_out_buffer + 2, thref); + break; + case 'T': + if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16)) { + error_packet(remcom_out_buffer, -EINVAL); + break; + } + ks->threadid = 0; + ptr = remcom_in_buffer + 17; + kgdb_hex2long(&ptr, &ks->threadid); + if (!getthread(ks->linux_regs, ks->threadid)) { + error_packet(remcom_out_buffer, -EINVAL); + break; + } + if (ks->threadid > 0) { + kgdb_mem2hex(getthread(ks->linux_regs, + ks->threadid)->comm, + remcom_out_buffer, 16); + } else { + static char tmpstr[23 + BUF_THREAD_ID_SIZE]; + + sprintf(tmpstr, "Shadow task %d for pid 0", + (int)(-ks->threadid-1)); + kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr)); + } + break; + } +} + +/* Handle the 'H' task query packets */ +static void gdb_cmd_task(struct kgdb_state *ks) +{ + struct task_struct *thread; + char *ptr; + + switch (remcom_in_buffer[1]) { + case 'g': + ptr = &remcom_in_buffer[2]; + kgdb_hex2long(&ptr, &ks->threadid); + thread = getthread(ks->linux_regs, ks->threadid); + if (!thread && ks->threadid > 0) { + error_packet(remcom_out_buffer, -EINVAL); + break; + } + kgdb_usethread = thread; + ks->kgdb_usethreadid = ks->threadid; + strcpy(remcom_out_buffer, "OK"); + break; + case 'c': + ptr = &remcom_in_buffer[2]; + kgdb_hex2long(&ptr, &ks->threadid); + if (!ks->threadid) { + kgdb_contthread = NULL; + } else { + thread = getthread(ks->linux_regs, ks->threadid); + if (!thread && ks->threadid > 0) { + error_packet(remcom_out_buffer, -EINVAL); + break; + } + kgdb_contthread = thread; + } + strcpy(remcom_out_buffer, "OK"); + break; + } +} + +/* Handle the 'T' thread query packets */ +static void gdb_cmd_thread(struct kgdb_state *ks) +{ + char *ptr = &remcom_in_buffer[1]; + struct task_struct *thread; + + kgdb_hex2long(&ptr, &ks->threadid); + thread = getthread(ks->linux_regs, ks->threadid); + if (thread) + strcpy(remcom_out_buffer, "OK"); + else + error_packet(remcom_out_buffer, -EINVAL); +} + +/* Handle the 'z' or 'Z' breakpoint remove or set packets */ +static void gdb_cmd_break(struct kgdb_state *ks) +{ + /* + * Since GDB-5.3, it's been drafted that '0' is a software + * breakpoint, '1' is a hardware breakpoint, so let's do that. + */ + char *bpt_type = &remcom_in_buffer[1]; + char *ptr = &remcom_in_buffer[2]; + unsigned long addr; + unsigned long length; + int error = 0; + + if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') { + /* Unsupported */ + if (*bpt_type > '4') + return; + } else { + if (*bpt_type != '0' && *bpt_type != '1') + /* Unsupported. */ + return; + } + + /* + * Test if this is a hardware breakpoint, and + * if we support it: + */ + if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT)) + /* Unsupported. */ + return; + + if (*(ptr++) != ',') { + error_packet(remcom_out_buffer, -EINVAL); + return; + } + if (!kgdb_hex2long(&ptr, &addr)) { + error_packet(remcom_out_buffer, -EINVAL); + return; + } + if (*(ptr++) != ',' || + !kgdb_hex2long(&ptr, &length)) { + error_packet(remcom_out_buffer, -EINVAL); + return; + } + + if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0') + error = kgdb_set_sw_break(addr); + else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0') + error = kgdb_remove_sw_break(addr); + else if (remcom_in_buffer[0] == 'Z') + error = arch_kgdb_ops.set_hw_breakpoint(addr, + (int)length, *bpt_type - '0'); + else if (remcom_in_buffer[0] == 'z') + error = arch_kgdb_ops.remove_hw_breakpoint(addr, + (int) length, *bpt_type - '0'); + + if (error == 0) + strcpy(remcom_out_buffer, "OK"); + else + error_packet(remcom_out_buffer, error); +} + +/* Handle the 'C' signal / exception passing packets */ +static int gdb_cmd_exception_pass(struct kgdb_state *ks) +{ + /* C09 == pass exception + * C15 == detach kgdb, pass exception + */ + if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') { + + ks->pass_exception = 1; + remcom_in_buffer[0] = 'c'; + + } else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') { + + ks->pass_exception = 1; + remcom_in_buffer[0] = 'D'; + remove_all_break(); + kgdb_connected = 0; + return 1; + + } else { + error_packet(remcom_out_buffer, -EINVAL); + return 0; + } + + /* Indicate fall through */ + return -1; +} + +/* + * This function performs all gdbserial command procesing + */ +static int gdb_serial_stub(struct kgdb_state *ks) +{ + int error = 0; + int tmp; + + /* Clear the out buffer. */ + memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); + + if (kgdb_connected) { + unsigned char thref[8]; + char *ptr; + + /* Reply to host that an exception has occurred */ + ptr = remcom_out_buffer; + *ptr++ = 'T'; + ptr = pack_hex_byte(ptr, ks->signo); + ptr += strlen(strcpy(ptr, "thread:")); + int_to_threadref(thref, shadow_pid(current->pid)); + ptr = pack_threadid(ptr, thref); + *ptr++ = ';'; + put_packet(remcom_out_buffer); + } + + kgdb_usethread = kgdb_info[ks->cpu].task; + ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid); + ks->pass_exception = 0; + + while (1) { + error = 0; + + /* Clear the out buffer. */ + memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); + + get_packet(remcom_in_buffer); + + switch (remcom_in_buffer[0]) { + case '?': /* gdbserial status */ + gdb_cmd_status(ks); + break; + case 'g': /* return the value of the CPU registers */ + gdb_cmd_getregs(ks); + break; + case 'G': /* set the value of the CPU registers - return OK */ + gdb_cmd_setregs(ks); + break; + case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ + gdb_cmd_memread(ks); + break; + case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */ + gdb_cmd_memwrite(ks); + break; + case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */ + gdb_cmd_binwrite(ks); + break; + /* kill or detach. KGDB should treat this like a + * continue. + */ + case 'D': /* Debugger detach */ + case 'k': /* Debugger detach via kill */ + gdb_cmd_detachkill(ks); + goto default_handle; + case 'R': /* Reboot */ + if (gdb_cmd_reboot(ks)) + goto default_handle; + break; + case 'q': /* query command */ + gdb_cmd_query(ks); + break; + case 'H': /* task related */ + gdb_cmd_task(ks); + break; + case 'T': /* Query thread status */ + gdb_cmd_thread(ks); + break; + case 'z': /* Break point remove */ + case 'Z': /* Break point set */ + gdb_cmd_break(ks); + break; + case 'C': /* Exception passing */ + tmp = gdb_cmd_exception_pass(ks); + if (tmp > 0) + goto default_handle; + if (tmp == 0) + break; + /* Fall through on tmp < 0 */ + case 'c': /* Continue packet */ + case 's': /* Single step packet */ + if (kgdb_contthread && kgdb_contthread != current) { + /* Can't switch threads in kgdb */ + error_packet(remcom_out_buffer, -EINVAL); + break; + } + kgdb_activate_sw_breakpoints(); + /* Fall through to default processing */ + default: +default_handle: + error = kgdb_arch_handle_exception(ks->ex_vector, + ks->signo, + ks->err_code, + remcom_in_buffer, + remcom_out_buffer, + ks->linux_regs); + /* + * Leave cmd processing on error, detach, + * kill, continue, or single step. + */ + if (error >= 0 || remcom_in_buffer[0] == 'D' || + remcom_in_buffer[0] == 'k') { + error = 0; + goto kgdb_exit; + } + + } + + /* reply to the request */ + put_packet(remcom_out_buffer); + } + +kgdb_exit: + if (ks->pass_exception) + error = 1; + return error; +} + +static int kgdb_reenter_check(struct kgdb_state *ks) +{ + unsigned long addr; + + if (atomic_read(&kgdb_active) != raw_smp_processor_id()) + return 0; + + /* Panic on recursive debugger calls: */ + exception_level++; + addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs); + kgdb_deactivate_sw_breakpoints(); + + /* + * If the break point removed ok at the place exception + * occurred, try to recover and print a warning to the end + * user because the user planted a breakpoint in a place that + * KGDB needs in order to function. + */ + if (kgdb_remove_sw_break(addr) == 0) { + exception_level = 0; + kgdb_skipexception(ks->ex_vector, ks->linux_regs); + kgdb_activate_sw_breakpoints(); + printk(KERN_CRIT "KGDB: re-enter error: breakpoint removed %lx\n", + addr); + WARN_ON_ONCE(1); + + return 1; + } + remove_all_break(); + kgdb_skipexception(ks->ex_vector, ks->linux_regs); + + if (exception_level > 1) { + dump_stack(); + panic("Recursive entry to debugger"); + } + + printk(KERN_CRIT "KGDB: re-enter exception: ALL breakpoints killed\n"); + dump_stack(); + panic("Recursive entry to debugger"); + + return 1; +} + +/* + * kgdb_handle_exception() - main entry point from a kernel exception + * + * Locking hierarchy: + * interface locks, if any (begin_session) + * kgdb lock (kgdb_active) + */ +int +kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs) +{ + struct kgdb_state kgdb_var; + struct kgdb_state *ks = &kgdb_var; + unsigned long flags; + int error = 0; + int i, cpu; + + ks->cpu = raw_smp_processor_id(); + ks->ex_vector = evector; + ks->signo = signo; + ks->ex_vector = evector; + ks->err_code = ecode; + ks->kgdb_usethreadid = 0; + ks->linux_regs = regs; + + if (kgdb_reenter_check(ks)) + return 0; /* Ouch, double exception ! */ + +acquirelock: + /* + * Interrupts will be restored by the 'trap return' code, except when + * single stepping. + */ + local_irq_save(flags); + + cpu = raw_smp_processor_id(); + + /* + * Acquire the kgdb_active lock: + */ + while (atomic_cmpxchg(&kgdb_active, -1, cpu) != -1) + cpu_relax(); + + /* + * Do not start the debugger connection on this CPU if the last + * instance of the exception handler wanted to come into the + * debugger on a different CPU via a single step + */ + if (atomic_read(&kgdb_cpu_doing_single_step) != -1 && + atomic_read(&kgdb_cpu_doing_single_step) != cpu) { + + atomic_set(&kgdb_active, -1); + clocksource_touch_watchdog(); + local_irq_restore(flags); + + goto acquirelock; + } + + if (!kgdb_io_ready(1)) { + error = 1; + goto kgdb_restore; /* No I/O connection, so resume the system */ + } + + /* + * Don't enter if we have hit a removed breakpoint. + */ + if (kgdb_skipexception(ks->ex_vector, ks->linux_regs)) + goto kgdb_restore; + + /* Call the I/O driver's pre_exception routine */ + if (kgdb_io_ops->pre_exception) + kgdb_io_ops->pre_exception(); + + kgdb_info[ks->cpu].debuggerinfo = ks->linux_regs; + kgdb_info[ks->cpu].task = current; + + kgdb_disable_hw_debug(ks->linux_regs); + + /* + * Get the passive CPU lock which will hold all the non-primary + * CPU in a spin state while the debugger is active + */ + if (!kgdb_single_step || !kgdb_contthread) { + for (i = 0; i < NR_CPUS; i++) + atomic_set(&passive_cpu_wait[i], 1); + } + + /* + * spin_lock code is good enough as a barrier so we don't + * need one here: + */ + atomic_set(&cpu_in_kgdb[ks->cpu], 1); + +#ifdef CONFIG_SMP + /* Signal the other CPUs to enter kgdb_wait() */ + if ((!kgdb_single_step || !kgdb_contthread) && kgdb_do_roundup) + kgdb_roundup_cpus(flags); +#endif + + /* + * Wait for the other CPUs to be notified and be waiting for us: + */ + for_each_online_cpu(i) { + while (!atomic_read(&cpu_in_kgdb[i])) + cpu_relax(); + } + + /* + * At this point the primary processor is completely + * in the debugger and all secondary CPUs are quiescent + */ + kgdb_post_primary_code(ks->linux_regs, ks->ex_vector, ks->err_code); + kgdb_deactivate_sw_breakpoints(); + kgdb_single_step = 0; + kgdb_contthread = NULL; + exception_level = 0; + + /* Talk to debugger with gdbserial protocol */ + error = gdb_serial_stub(ks); + + /* Call the I/O driver's post_exception routine */ + if (kgdb_io_ops->post_exception) + kgdb_io_ops->post_exception(); + + kgdb_info[ks->cpu].debuggerinfo = NULL; + kgdb_info[ks->cpu].task = NULL; + atomic_set(&cpu_in_kgdb[ks->cpu], 0); + + if (!kgdb_single_step || !kgdb_contthread) { + for (i = NR_CPUS-1; i >= 0; i--) + atomic_set(&passive_cpu_wait[i], 0); + /* + * Wait till all the CPUs have quit + * from the debugger. + */ + for_each_online_cpu(i) { + while (atomic_read(&cpu_in_kgdb[i])) + cpu_relax(); + } + } + +kgdb_restore: + /* Free kgdb_active */ + atomic_set(&kgdb_active, -1); + clocksource_touch_watchdog(); + local_irq_restore(flags); + + return error; +} + +int kgdb_nmicallback(int cpu, void *regs) +{ +#ifdef CONFIG_SMP + if (!atomic_read(&cpu_in_kgdb[cpu]) && + atomic_read(&kgdb_active) != cpu && + atomic_read(&cpu_in_kgdb[atomic_read(&kgdb_active)])) { + kgdb_wait((struct pt_regs *)regs); + return 0; + } +#endif + return 1; +} + +void kgdb_console_write(struct console *co, const char *s, unsigned count) +{ + unsigned long flags; + + /* If we're debugging, or KGDB has not connected, don't try + * and print. */ + if (!kgdb_connected || atomic_read(&kgdb_active) != -1) + return; + + local_irq_save(flags); + kgdb_msg_write(s, count); + local_irq_restore(flags); +} + +static struct console kgdbcons = { + .name = "kgdb", + .write = kgdb_console_write, + .flags = CON_PRINTBUFFER | CON_ENABLED, + .index = -1, +}; + +#ifdef CONFIG_MAGIC_SYSRQ +static void sysrq_handle_gdb(int key, struct tty_struct *tty) +{ + if (!kgdb_io_ops) { + printk(KERN_CRIT "ERROR: No KGDB I/O module available\n"); + return; + } + if (!kgdb_connected) + printk(KERN_CRIT "Entering KGDB\n"); + + kgdb_breakpoint(); +} + +static struct sysrq_key_op sysrq_gdb_op = { + .handler = sysrq_handle_gdb, + .help_msg = "Gdb", + .action_msg = "GDB", +}; +#endif + +static void kgdb_register_callbacks(void) +{ + if (!kgdb_io_module_registered) { + kgdb_io_module_registered = 1; + kgdb_arch_init(); +#ifdef CONFIG_MAGIC_SYSRQ + register_sysrq_key('g', &sysrq_gdb_op); +#endif + if (kgdb_use_con && !kgdb_con_registered) { + register_console(&kgdbcons); + kgdb_con_registered = 1; + } + } +} + +static void kgdb_unregister_callbacks(void) +{ + /* + * When this routine is called KGDB should unregister from the + * panic handler and clean up, making sure it is not handling any + * break exceptions at the time. + */ + if (kgdb_io_module_registered) { + kgdb_io_module_registered = 0; + kgdb_arch_exit(); +#ifdef CONFIG_MAGIC_SYSRQ + unregister_sysrq_key('g', &sysrq_gdb_op); +#endif + if (kgdb_con_registered) { + unregister_console(&kgdbcons); + kgdb_con_registered = 0; + } + } +} + +static void kgdb_initial_breakpoint(void) +{ + kgdb_break_asap = 0; + + printk(KERN_CRIT "kgdb: Waiting for connection from remote gdb...\n"); + kgdb_breakpoint(); +} + +/** + * kgdb_register_io_module - register KGDB IO module + * @new_kgdb_io_ops: the io ops vector + * + * Register it with the KGDB core. + */ +int kgdb_register_io_module(struct kgdb_io *new_kgdb_io_ops) +{ + int err; + + spin_lock(&kgdb_registration_lock); + + if (kgdb_io_ops) { + spin_unlock(&kgdb_registration_lock); + + printk(KERN_ERR "kgdb: Another I/O driver is already " + "registered with KGDB.\n"); + return -EBUSY; + } + + if (new_kgdb_io_ops->init) { + err = new_kgdb_io_ops->init(); + if (err) { + spin_unlock(&kgdb_registration_lock); + return err; + } + } + + kgdb_io_ops = new_kgdb_io_ops; + + spin_unlock(&kgdb_registration_lock); + + printk(KERN_INFO "kgdb: Registered I/O driver %s.\n", + new_kgdb_io_ops->name); + + /* Arm KGDB now. */ + kgdb_register_callbacks(); + + if (kgdb_break_asap) + kgdb_initial_breakpoint(); + + return 0; +} +EXPORT_SYMBOL_GPL(kgdb_register_io_module); + +/** + * kkgdb_unregister_io_module - unregister KGDB IO module + * @old_kgdb_io_ops: the io ops vector + * + * Unregister it with the KGDB core. + */ +void kgdb_unregister_io_module(struct kgdb_io *old_kgdb_io_ops) +{ + BUG_ON(kgdb_connected); + + /* + * KGDB is no longer able to communicate out, so + * unregister our callbacks and reset state. + */ + kgdb_unregister_callbacks(); + + spin_lock(&kgdb_registration_lock); + + WARN_ON_ONCE(kgdb_io_ops != old_kgdb_io_ops); + kgdb_io_ops = NULL; + + spin_unlock(&kgdb_registration_lock); + + printk(KERN_INFO + "kgdb: Unregistered I/O driver %s, debugger disabled.\n", + old_kgdb_io_ops->name); +} +EXPORT_SYMBOL_GPL(kgdb_unregister_io_module); + +/** + * kgdb_breakpoint - generate breakpoint exception + * + * This function will generate a breakpoint exception. It is used at the + * beginning of a program to sync up with a debugger and can be used + * otherwise as a quick means to stop program execution and "break" into + * the debugger. + */ +void kgdb_breakpoint(void) +{ + atomic_set(&kgdb_setting_breakpoint, 1); + wmb(); /* Sync point before breakpoint */ + arch_kgdb_breakpoint(); + wmb(); /* Sync point after breakpoint */ + atomic_set(&kgdb_setting_breakpoint, 0); +} +EXPORT_SYMBOL_GPL(kgdb_breakpoint); + +static int __init opt_kgdb_wait(char *str) +{ + kgdb_break_asap = 1; + + if (kgdb_io_module_registered) + kgdb_initial_breakpoint(); + + return 0; +} + +early_param("kgdbwait", opt_kgdb_wait); diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 7f60097d443..f61402b1f2d 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -222,6 +222,18 @@ void clocksource_resume(void) } /** + * clocksource_touch_watchdog - Update watchdog + * + * Update the watchdog after exception contexts such as kgdb so as not + * to incorrectly trip the watchdog. + * + */ +void clocksource_touch_watchdog(void) +{ + clocksource_resume_watchdog(); +} + +/** * clocksource_get_next - Returns the selected clocksource * */ diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 80db357b0a4..aaba784332e 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -612,3 +612,5 @@ config PROVIDE_OHCI1394_DMA_INIT See Documentation/debugging-via-ohci1394.txt for more information. source "samples/Kconfig" + +source "lib/Kconfig.kgdb" diff --git a/lib/Kconfig.kgdb b/lib/Kconfig.kgdb new file mode 100644 index 00000000000..f2e01ac5ab0 --- /dev/null +++ b/lib/Kconfig.kgdb @@ -0,0 +1,58 @@ + +menuconfig KGDB + bool "KGDB: kernel debugging with remote gdb" + select FRAME_POINTER + depends on HAVE_ARCH_KGDB + depends on DEBUG_KERNEL && EXPERIMENTAL + help + If you say Y here, it will be possible to remotely debug the + kernel using gdb. Documentation of kernel debugger is available + at http://kgdb.sourceforge.net as well as in DocBook form + in Documentation/DocBook/. If unsure, say N. + +config HAVE_ARCH_KGDB_SHADOW_INFO + bool + +config HAVE_ARCH_KGDB + bool + +config KGDB_SERIAL_CONSOLE + tristate "KGDB: use kgdb over the serial console" + depends on KGDB + select CONSOLE_POLL + select MAGIC_SYSRQ + default y + help + Share a serial console with kgdb. Sysrq-g must be used + to break in initially. + +config KGDB_TESTS + bool "KGDB: internal test suite" + depends on KGDB + default n + help + This is a kgdb I/O module specifically designed to test + kgdb's internal functions. This kgdb I/O module is + intended to for the development of new kgdb stubs + as well as regression testing the kgdb internals. + See the drivers/misc/kgdbts.c for the details about + the tests. The most basic of this I/O module is to boot + a kernel boot arguments "kgdbwait kgdbts=V1F100" + +config KGDB_TESTS_ON_BOOT + bool "KGDB: Run tests on boot" + depends on KGDB_TESTS + default n + help + Run the kgdb tests on boot up automatically without the need + to pass in a kernel parameter + +config KGDB_TESTS_BOOT_STRING + string "KGDB: which internal kgdb tests to run" + depends on KGDB_TESTS_ON_BOOT + default "V1F100" + help + This is the command string to send the kgdb test suite on + boot. See the drivers/misc/kgdbts.c for detailed + information about other strings you could use beyond the + default of V1F100. diff --git a/mm/Makefile b/mm/Makefile index a5b0dd93427..18c143b3c46 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -8,7 +8,7 @@ mmu-$(CONFIG_MMU) := fremap.o highmem.o madvise.o memory.o mincore.o \ vmalloc.o obj-y := bootmem.o filemap.o mempool.o oom_kill.o fadvise.o \ - page_alloc.o page-writeback.o pdflush.o \ + maccess.o page_alloc.o page-writeback.o pdflush.o \ readahead.o swap.o truncate.o vmscan.o \ prio_tree.o util.o mmzone.o vmstat.o backing-dev.o \ page_isolation.o $(mmu-y) diff --git a/mm/maccess.c b/mm/maccess.c new file mode 100644 index 00000000000..ac40796cfb1 --- /dev/null +++ b/mm/maccess.c @@ -0,0 +1,55 @@ +/* + * Access kernel memory without faulting. + */ +#include <linux/uaccess.h> +#include <linux/module.h> +#include <linux/mm.h> + +/** + * probe_kernel_read(): safely attempt to read from a location + * @dst: pointer to the buffer that shall take the data + * @src: address to read from + * @size: size of the data chunk + * + * Safely read from address @src to the buffer at @dst. If a kernel fault + * happens, handle that and return -EFAULT. + */ +long probe_kernel_read(void *dst, void *src, size_t size) +{ + long ret; + mm_segment_t old_fs = get_fs(); + + set_fs(KERNEL_DS); + pagefault_disable(); + ret = __copy_from_user_inatomic(dst, + (__force const void __user *)src, size); + pagefault_enable(); + set_fs(old_fs); + + return ret ? -EFAULT : 0; +} +EXPORT_SYMBOL_GPL(probe_kernel_read); + +/** + * probe_kernel_write(): safely attempt to write to a location + * @dst: address to write to + * @src: pointer to the data that shall be written + * @size: size of the data chunk + * + * Safely write to address @dst from the buffer at @src. If a kernel fault + * happens, handle that and return -EFAULT. + */ +long probe_kernel_write(void *dst, void *src, size_t size) +{ + long ret; + mm_segment_t old_fs = get_fs(); + + set_fs(KERNEL_DS); + pagefault_disable(); + ret = __copy_to_user_inatomic((__force void __user *)dst, src, size); + pagefault_enable(); + set_fs(old_fs); + + return ret ? -EFAULT : 0; +} +EXPORT_SYMBOL_GPL(probe_kernel_write); |