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path: root/arch/tile/kernel/signal.c
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2011-05-19arch/tile: support signal "exception-trace" hookChris Metcalf
This change adds support for /proc/sys/debug/exception-trace to tile. Like x86 and sparc, by default it is set to "1", generating a one-line printk whenever a user process crashes. By setting it to "2", we get a much more complete userspace diagnostic at crash time, including a user-space backtrace, register dump, and memory dump around the address of the crash. Some vestiges of the Tilera-internal version of this support are removed with this patch (the show_crashinfo variable and the arch_coredump_signal function). We retain a "crashinfo" boot parameter which allows you to set the boot-time value of exception-trace. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-12-17arch/tile: handle rt_sigreturn() more cleanlyChris Metcalf
The current tile rt_sigreturn() syscall pattern uses the common idiom of loading up pt_regs with all the saved registers from the time of the signal, then anticipating the fact that we will clobber the ABI "return value" register (r0) as we return from the syscall by setting the rt_sigreturn return value to whatever random value was in the pt_regs for r0. However, this breaks in our 64-bit kernel when running "compat" tasks, since we always sign-extend the "return value" register to properly handle returned pointers that are in the upper 2GB of the 32-bit compat address space. Doing this to the sigreturn path then causes occasional random corruption of the 64-bit r0 register. Instead, we stop doing the crazy "load the return-value register" hack in sigreturn. We already have some sigreturn-specific assembly code that we use to pass the pt_regs pointer to C code. We extend that code to also set the link register to point to a spot a few instructions after the usual syscall return address so we don't clobber the saved r0. Now it no longer matters what the rt_sigreturn syscall returns, and the pt_regs structure can be cleanly and completely reloaded. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-17BKL: remove extraneous #include <smp_lock.h>Arnd Bergmann
The big kernel lock has been removed from all these files at some point, leaving only the #include. Remove this too as a cleanup. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-01arch/tile: don't allow user code to set the PL via ptrace or signal returnChris Metcalf
The kernel was allowing any component of the pt_regs to be updated either by signal handlers writing to the stack, or by processes writing via PTRACE_POKEUSR or PTRACE_SETREGS, which meant they could set their PL up from 0 to 1 and get access to kernel code and data (or, in practice, cause a kernel panic). We now always reset the ex1 field, allowing the user to set their ICS bit only. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-01arch/tile: correct double syscall restart for nested signalsChris Metcalf
This change is modelled on similar fixes for other architectures. The pt_regs "faultnum" member is set to the trap (fault) number that caused us to enter the kernel, and is INT_SWINT_1 for the syscall software interrupt. We already supported a pseudo value, INT_SWINT_1_SIGRETURN, that we used for the rt_sigreturn syscall; it avoided the case where one signal was handled, then we "tail-called" to another handler. This change avoids the similar case where we start to call one handler, then are preempted into another handler when we start trying to run the first handler. We clear ->faultnum after calling handle_signal(), and to be paranoid also in the case where there was no signal to deliver. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14arch/tile: Use <asm-generic/syscalls.h>Chris Metcalf
With this change we now include <asm-generic/syscalls.h> into the "tile" version of the header. To take full advantage of the prototypes there, we also change our naming convention for "struct pt_regs *" syscalls so that, e.g., _sys_execve() is the "true" syscall entry, which sets the appropriate register to point to the pt_regs before calling sys_execve(). While doing this I realized I no longer needed the fork and vfork entry point stubs, since those functions aren't in the generic syscall ABI, so I removed them as well. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-09-15arch/tile: Change struct sigcontext to be more usefulChris Metcalf
Rather than just using pt_regs, it now contains the actual saved state explicitly, similar to pt_regs. By doing it this way, we provide a cleaner API for userspace (or equivalently, we avoid the need for libc to provide its own definition of sigcontext). While we're at it, move PT_FLAGS_xxx to where they are not visible from userspace. And always pass siginfo and mcontext to signal handlers, even if they claim they don't need it, since sometimes they actually try to use it anyway in practice. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-07-06arch/tile: Miscellaneous cleanup changes.Chris Metcalf
This commit is primarily changes caused by reviewing "sparse" and "checkpatch" output on our sources, so is somewhat noisy, since things like "printk() -> pr_err()" (or whatever) throughout the codebase tend to get tedious to read. Rather than trying to tease apart precisely which things changed due to which type of code review, this commit includes various cleanups in the code: - sparse: Add declarations in headers for globals. - sparse: Fix __user annotations. - sparse: Using gfp_t consistently instead of int. - sparse: removing functions not actually used. - checkpatch: Clean up printk() warnings by using pr_info(), etc.; also avoid partial-line printks except in bootup code. - checkpatch: Use exposed structs rather than typedefs. - checkpatch: Change some C99 comments to C89 comments. In addition, a couple of minor other changes are rolled in to this commit: - Add support for a "raise" instruction to cause SIGFPE, etc., to be raised. - Remove some compat code that is unnecessary when we fully eliminate some of the deprecated syscalls from the generic syscall ABI. - Update the tile_defconfig to reflect current config contents. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2010-06-07Revert adding some arch-specific signal syscalls to <linux/syscalls.h>.Chris Metcalf
It turns out there is some variance on the calling conventions for these syscalls, and <asm-generic/syscalls.h> is already the mechanism used to handle this. Switch arch/tile over to using that mechanism and tweak the calling conventions for a couple of tile syscalls to match <asm-generic/syscalls.h>. Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-06-04arch/tile: core support for Tilera 32-bit chips.Chris Metcalf
This change is the core kernel support for TILEPro and TILE64 chips. No driver support (except the console driver) is included yet. This includes the relevant Linux headers in asm/; the low-level low-level "Tile architecture" headers in arch/, which are shared with the hypervisor, etc., and are build-system agnostic; and the relevant hypervisor headers in hv/. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Reviewed-by: Paul Mundt <lethal@linux-sh.org>