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2008-07-17sparc64/kernel/: make code staticAdrian Bunk
This patch makes the following needlessly global code static: - central.c: struct central_bus - central.c: struct fhc_list - central.c: apply_fhc_ranges() - central.c: apply_central_ranges() - ds.c: struct ds_states_template[] - pci_msi.c: sparc64_setup_msi_irq() - pci_msi.c: sparc64_teardown_msi_irq() - pci_sun4v.c: struct sun4v_dma_ops - sys_sparc32.c: cp_compat_stat64() Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-16Merge branch 'linux-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 * 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (72 commits) Revert "x86/PCI: ACPI based PCI gap calculation" PCI: remove unnecessary volatile in PCIe hotplug struct controller x86/PCI: ACPI based PCI gap calculation PCI: include linux/pm_wakeup.h for device_set_wakeup_capable PCI PM: Fix pci_prepare_to_sleep x86/PCI: Fix PCI config space for domains > 0 Fix acpi_pm_device_sleep_wake() by providing a stub for CONFIG_PM_SLEEP=n PCI: Simplify PCI device PM code PCI PM: Introduce pci_prepare_to_sleep and pci_back_from_sleep PCI ACPI: Rework PCI handling of wake-up ACPI: Introduce new device wakeup flag 'prepared' ACPI: Introduce acpi_device_sleep_wake function PCI: rework pci_set_power_state function to call platform first PCI: Introduce platform_pci_power_manageable function ACPI: Introduce acpi_bus_power_manageable function PCI: make pci_name use dev_name PCI: handle pci_name() being const PCI: add stub for pci_set_consistent_dma_mask() PCI: remove unused arch pcibios_update_resource() functions PCI: fix pci_setup_device()'s sprinting into a const buffer ... Fixed up conflicts in various files (arch/x86/kernel/setup_64.c, arch/x86/pci/irq.c, arch/x86/pci/pci.h, drivers/acpi/sleep/main.c, drivers/pci/pci.c, drivers/pci/pci.h, include/acpi/acpi_bus.h) from x86 and ACPI updates manually.
2008-07-15Merge branch 'generic-ipi' into generic-ipi-for-linusIngo Molnar
Conflicts: arch/powerpc/Kconfig arch/s390/kernel/time.c arch/x86/kernel/apic_32.c arch/x86/kernel/cpu/perfctr-watchdog.c arch/x86/kernel/i8259_64.c arch/x86/kernel/ldt.c arch/x86/kernel/nmi_64.c arch/x86/kernel/smpboot.c arch/x86/xen/smp.c include/asm-x86/hw_irq_32.h include/asm-x86/hw_irq_64.h include/asm-x86/mach-default/irq_vectors.h include/asm-x86/mach-voyager/irq_vectors.h include/asm-x86/smp.h kernel/Makefile Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-15Merge branch 'core/stacktrace' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core/stacktrace' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: generic-ipi: powerpc/generic-ipi tree build failure stacktrace: fix build failure on sparc64 stacktrace: export save_stack_trace[_tsk] stacktrace: fix modular build, export print_stack_trace and save_stack_trace backtrace: replace timer with tasklet + completions stacktrace: add saved stack traces to backtrace self-test stacktrace: print_stack_trace() cleanup debugging: make stacktrace independent from DEBUG_KERNEL stacktrace: don't crash on invalid stack trace structs
2008-07-14Merge branch 'tracing/for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (228 commits) ftrace: build fix for ftraced_suspend ftrace: separate out the function enabled variable ftrace: add ftrace_kill_atomic ftrace: use current CPU for function startup ftrace: start wakeup tracing after setting function tracer ftrace: check proper config for preempt type ftrace: trace schedule ftrace: define function trace nop ftrace: move sched_switch enable after markers ftrace: prevent ftrace modifications while being kprobe'd, v2 fix "ftrace: store mcount address in rec->ip" mmiotrace broken in linux-next (8-bit writes only) ftrace: avoid modifying kprobe'd records ftrace: freeze kprobe'd records kprobes: enable clean usage of get_kprobe ftrace: store mcount address in rec->ip ftrace: build fix with gcc 4.3 namespacecheck: fixes ftrace: fix "notrace" filtering priority ftrace: fix printout ...
2008-07-14Merge commit 'v2.6.26' into bkl-removalJonathan Corbet
2008-07-08stacktrace: fix build failure on sparc64Stephen Rothwell
Today's linux-next build (spac64 allmodconfig) failed like this: arch/sparc64/kernel/stacktrace.c:50: warning: type defaults to `int' in declaration of `EXPORT_SYMBOL_GPL' arch/sparc64/kernel/stacktrace.c:50: warning: parameter names (without types) in function declaration arch/sparc64/kernel/stacktrace.c:50: warning: data definition has no type or storage class Signed-off-by: Stephen Rothwell <sf@canb.auug.org.au> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-07PCI: make pci_name use dev_nameGreg KH
Also fixes up the sparc code that was assuming this is not a constant. Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-07-03stacktrace: export save_stack_trace[_tsk]Ingo Molnar
Andrew Morton reported this against linux-next: ERROR: ".save_stack_trace" [tests/backtracetest.ko] undefined! Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-02sparc64-rtc: BKL pushdownArnd Bergmann
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2008-07-01fix "ftrace: store mcount address in rec->ip"Ingo Molnar
Alexander Beregalov reported this build failure: $ make CROSS_COMPILE=sparc64-unknown-linux-gnu- image modules && sudo make modules_install CHK include/linux/version.h CHK include/linux/utsrelease.h CALL scripts/checksyscalls.sh CHK include/linux/compile.h dnsdomainname: Unknown host CC arch/sparc64/kernel/sparc64_ksyms.o arch/sparc64/kernel/sparc64_ksyms.c:116: error: '_mcount' undeclared here (not in a function) cc1: warnings being treated as errors arch/sparc64/kernel/sparc64_ksyms.c:116: error: type defaults to 'int' in declaration of '_mcount' And bisected it back to: | commit 395a59d0f8e86bb39cd700c3d185d30c670bb958 | Author: Abhishek Sagar <sagar.abhishek@gmail.com> | Date: Sat Jun 21 23:47:27 2008 +0530 | | ftrace: store mcount address in rec->ip the mcount prototype is only available under CONFIG_FTRACE, extend it to CONFIG_MCOUNT as well. Reported-and-bisected-by: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-26smp_call_function: get rid of the unused nonatomic/retry argumentJens Axboe
It's never used and the comments refer to nonatomic and retry interchangably. So get rid of it. Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-06-26Add generic helpers for arch IPI function callsJens Axboe
This adds kernel/smp.c which contains helpers for IPI function calls. In addition to supporting the existing smp_call_function() in a more efficient manner, it also adds a more scalable variant called smp_call_function_single() for calling a given function on a single CPU only. The core of this is based on the x86-64 patch from Nick Piggin, lots of changes since then. "Alan D. Brunelle" <Alan.Brunelle@hp.com> has contributed lots of fixes and suggestions as well. Also thanks to Paul E. McKenney <paulmck@linux.vnet.ibm.com> for reviewing RCU usage and getting rid of the data allocation fallback deadlock. Acked-by: Ingo Molnar <mingo@elte.hu> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-06-23ftrace: store mcount address in rec->ipAbhishek Sagar
Record the address of the mcount call-site. Currently all archs except sparc64 record the address of the instruction following the mcount call-site. Some general cleanups are entailed. Storing mcount addresses in rec->ip enables looking them up in the kprobe hash table later on to check if they're kprobe'd. Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com> Cc: davem@davemloft.net Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-10ftrace: remove ftrace_ip_converted()Abhishek Sagar
Remove the unneeded function ftrace_ip_converted(). Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-23sparc64: add ftrace support.David Miller
Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-21sparc64: Prevent stack backtrace false positives on trap frames.David S. Miller
When we fully commit to returning back to kernel mode from a trap, zero out the regs->magic value to prevent false positives during stack backtraces. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-21sparc64: Fix stack tracing through trap frames.David S. Miller
The offset to the pt_regs area was wrong, so we weren't looking at the right location for the magic cookie. A trap frame is composed of a "struct sparc_stackf" then a "struct pt_regs", the code was using "struct reg_window" instead of "struct sparc_stackf". Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-21sparc64: Fix kernel thread stack termination.David S. Miller
Because of the silly way I set up the initial stack for new kernel threads, there is a loop at the top of the stack. To fix this, properly add another stack frame that is copied from the parent and terminate it in the child by setting the frame pointer in that frame to zero. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-20sparc64: Add global register dumping facility.David S. Miller
When a cpu really is stuck in the kernel, it can be often impossible to figure out which cpu is stuck where. The worst case is when the stuck cpu has interrupts disabled. Therefore, implement a global cpu state capture that uses SMP message interrupts which are not disabled by the normal IRQ enable/disable APIs of the kernel. As long as we can get a sysrq 'y' to the kernel, we can get a dump. Even if the console interrupt cpu is wedged, we can trigger it from userspace using /proc/sysrq-trigger The output is made compact so that this facility is more useful on high cpu count systems, which is where this facility will likely find itself the most useful :) Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-20sparc64: remove CVS keywordsAdrian Bunk
This patch removes the CVS keywords that weren't updated for a long time from comments. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-16[PATCH] take init_files to fs/file.cAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-05-12sparc64: Use a TS_RESTORE_SIGMASKDavid S. Miller
This mirrors x86 changeset 5a8da0ea82db6fa9737041381079fd16f25dcce2 ("signals: x86 TS_RESTORE_SIGMASK") on sparc64. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-12sparc: Fix mremap address range validation.David S. Miller
Just like mmap, we need to validate address ranges regardless of MAP_FIXED. sparc{,64}_mmap_check()'s flag argument is unused, remove. Based upon a report and preliminary patch by Jan Lieskovsky <jlieskov@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-11sparc: Fix debugger syscall restart interactions.David S. Miller
So, forever, we've had this ptrace_signal_deliver implementation which tries to handle all of the nasties that can occur when the debugger looks at a process about to take a signal. It's meant to address all of these issues inside of the kernel so that the debugger need not be mindful of such things. Problem is, this doesn't work. The idea was that we should do the syscall restart business first, so that the debugger captures that state. Otherwise, if the debugger for example saves the child's state, makes the child execute something else, then restores the saved state, we won't handle the syscall restart properly because we lose the "we're in a syscall" state. The code here worked for most cases, but if the debugger actually passes the signal through to the child unaltered, it's possible that we would do a syscall restart when we shouldn't have. In particular this breaks the case of debugging a process under a gdb which is being debugged by yet another gdb. gdb uses sigsuspend to wait for SIGCHLD of the inferior, but if gdb itself is being debugged by a top-level gdb we get a ptrace_stop(). The top-level gdb does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the signal. But ptrace_signal_deliver() assumed the debugger would cancel out the signal and therefore did a syscall restart, because the return error was ERESTARTNOHAND. Fix this by simply making ptrace_signal_deliver() a nop, and providing a way for the debugger to control system call restarting properly: 1) Report a "in syscall" software bit in regs->{tstate,psr}. It is set early on in trap entry to a system call and is fully visible to the debugger via ptrace() and regsets. 2) Test this bit right before doing a syscall restart. We have to do a final recheck right after get_signal_to_deliver() in case the debugger cleared the bit during ptrace_stop(). 3) Clear the bit in trap return so we don't accidently try to set that bit in the real register. As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just like sparc64 has. M68K has this same exact bug, and is now the only other user of the ptrace_signal_deliver hook. It needs to be fixed in the same exact way as sparc. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-11sparc: Fix ptrace() detach.David S. Miller
Forever we had a PTRACE_SUNOS_DETACH which was unconditionally recognized, regardless of the personality of the process. Unfortunately, this value is what ended up in the GLIBC sys/ptrace.h header file on sparc as PTRACE_DETACH and PT_DETACH. So continue to recognize this old value. Luckily, it doesn't conflict with anything we actually care about. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-07sparc: Fix SA_ONSTACK signal handling.David S. Miller
We need to be more liberal about the alignment of the buffer given to us by sigaltstack(). The user should not need to be mindful of all of the alignment constraints we have for the stack frame. This mirrors how we handle this situation in clone() as well. Also, we align the stack even in non-SA_ONSTACK cases so that signals due to bad stack alignment can be delivered properly. This makes such errors easier to debug and recover from. Finally, add the sanity check x86 has to make sure we won't overflow the signal stack. This fixes glibc testcases nptl/tst-cancel20.c and nptl/tst-cancelx20.c Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-07sparc: Fix fork/clone/vfork system call restart.David S. Miller
We clobber %i1 as well as %i0 for these system calls, because they give two return values. Therefore, on error, we have to restore %i1 properly or else the restart explodes since it uses the wrong arguments. This fixes glibc's nptl/tst-eintr1.c testcase. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-07sparc: Fix mmap VA span checking.David S. Miller
We should not conditionalize VA range checks on MAP_FIXED. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-05sparc64: use compat_sys_utimes instead of home-grown local copy.David S. Miller
Noticed by Christoph Hellwig. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-03Revert "[SPARC64]: Wrap SMP IPIs with irq_enter()/irq_exit()."David S. Miller
This reverts commit 2664ef44cf5053d2b7dff01cecac70bc601a5f68. Ingo moved around where the softlockup dependency sits so this change is no longer necessary. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-02sparc64: Fix syscall restart, for real...David S. Miller
The change I put into copy_thread() just papered over the real problem. When we are looking to see if we should do a syscall restart, when deliverying a signal, we should only interpret the syscall return value as an error if the carry condition code(s) are set. Otherwise it's a success return. Also, sigreturn paths should do a pt_regs_clear_trap_type(). It turns out that doing a syscall restart when returning from a fork() does and should happen, from time to time. Even if copy_thread() returns success, copy_process() can still unwind and signal -ERESTARTNOINTR in the parent. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-02sparc64: Stop creating dummy root PCI host controller devices.David S. Miller
It just creates confusion, errors, and bugs. For one thing, this can cause dup sysfs or procfs nodes to get created: [ 1.198015] proc_dir_entry '00.0' already registered [ 1.198036] Call Trace: [ 1.198052] [00000000004f2534] create_proc_entry+0x7c/0x98 [ 1.198092] [00000000005719e4] pci_proc_attach_device+0xa4/0xd4 [ 1.198126] [00000000007d991c] pci_proc_init+0x64/0x88 [ 1.198158] [00000000007c62a4] kernel_init+0x190/0x330 [ 1.198183] [0000000000426cf8] kernel_thread+0x38/0x48 [ 1.198210] [00000000006a0d90] rest_init+0x18/0x5c Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-29sparc64: remove duplicated includeHuang Weiyi
Remove dulicated include file <asm/timer.h> in arch/sparc64/kernel/smp.c. Signed-off-by: Huang Weiyi <hwy@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-29sparc: Add kgdb support.David S. Miller
Current limitations: 1) On SMP single stepping has some fundamental issues, shared with other sw single-step architectures such as mips and arm. 2) On 32-bit sparc we don't support SMP kgdb yet. That requires some reworking of the IPI mechanisms and infrastructure on that platform. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-28sparc64: Split entry.S up into seperate files.David S. Miller
entry.S was a hodge-podge of several totally unrelated sets of assembler routines, ranging from FPU trap handlers to hypervisor call functions. Split it up into topic-sized pieces. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-27sparc64: Fix accidental syscall restart on child return from clone/fork/vfork.David S. Miller
This fixes a regression added by 238468b2ac76020c192a7402c92df5097916bf4a ("[SPARC64]: Use trap type stored in pt_regs to handle syscall restart.") Because we now encode the "returning from syscall" status in the pt_regs area, we have to be mindful to zap it out in the child of a fork. During a parallel kernel build I saw an accidental -EINTR return from vfork() in 'make' because of this bug. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-27sparc64: Clean up handling of pt_regs trap type encoding.David S. Miller
If we use this from more than one place, it's better to have helpers instead of twiddling magic constants all over. Add pt_regs_trap_type(), pt_regs_clear_trap_type(), and pt_regs_is_syscall(). Use them in do_signal(). Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-27sparc: Remove old style signal frame support.David S. Miller
Back around the same time we were bootstrapping the first 32-bit sparc Linux kernel with a SunOS userland, we made the signal frame match that of SunOS. By the time we even started putting together a native Linux userland for 32-bit Sparc we realized this layout wasn't sufficient for Linux's needs. Therefore we changed the layout, yet kept support for the old style signal frame layout in there. The detection mechanism is that we had sys_sigaction() start passing in a negative signal number to indicate "new style signal frames please". Anyways, no binaries exist in the world that use the old stuff. In fact, I bet Jakub Jelinek and myself are the only two people who ever had such binaries to be honest. So let's get rid of this stuff. I added an assertion using WARN_ON_ONCE() that makes sure 32-bit applications are passing in that negative signal number still. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-27sparc64: Kill bogus RT_ALIGNEDSZ macro from signal.cDavid S. Miller
The structure has to be 8-byte aligned in size, so this macro is just noise. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-26sparc64: Kill unused local ISA bus layer.David S. Miller
No more drivers use this, and therefore it can die. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-26sparc64: Do not ignore 'pmu' device ranges.David S. Miller
I must have disabled this due to other bugs which were fixed over time. And this is needed in order for child devices of "pmu" to get proper resource values. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-26sparc64: Kill CONFIG_SPARC32_COMPATDavid S. Miller
It's completely superfluous, CONFIG_COMPAT is sufficient. What this used to be is an umbrella for enabling code shared by all 32-bit compat binary support types. But with the removal of SunOS and Solaris support, the only one left is Linux 32-bit ELF. Update defconfig. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-26sparc64: Fix wedged irq regression.David S. Miller
Kernel bugzilla 10273 As reported by Jos van der Ende, ever since commit 5a606b72a4309a656cd1a19ad137dc5557c4b8ea ("[SPARC64]: Do not ACK an INO if it is disabled or inprogress.") sun4u interrupts can get stuck. What this changset did was add the following conditional to the various IRQ chip ->enable() handlers on sparc64: if (unlikely(desc->status & (IRQ_DISABLED|IRQ_INPROGRESS))) return; which is correct, however it means that special care is needed in the ->enable() method. Specifically we must put the interrupt into IDLE state during an enable, or else it might never be sent out again. Setting the INO interrupt state to IDLE resets the state machine, the interrupt input to the INO is retested by the hardware, and if an interrupt is being signalled by the device, the INO moves back into TRANSMIT state, and an interrupt vector is sent to the cpu. The two sun4v IRQ chip handlers were already doing this properly, only sun4u got it wrong. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-25[SPARC64]: Wrap SMP IPIs with irq_enter()/irq_exit().David S. Miller
Otherwise all sorts of bad things can happen, including spurious softlockup reports. Other platforms have this same bug, in one form or another, just don't see the issue because they don't sleep as long as sparc64 can in NOHZ. Thanks to some brilliant debugging by Peter Zijlstra. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-25[SPARC64]: Fix args to 64-bit sys_semctl() via sys_ipc().David S. Miller
Second and third arguments were swapped for whatever reason. Reported by Tom Callaway. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-24[SPARC64]: Detect trap frames in stack backtraces.David S. Miller
Now that we have a magic cookie in the pt_regs, we can properly detect trap frames in stack bactraces. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-24[SPARC64]: %l6 trap return handling no longer necessary.David S. Miller
Now that we indicate the "restart system call" in the trap type field of pt_regs->magic, we don't need to set the %l6 boolean in all of the trap return paths. And we therefore don't need to pass it to do_notify_resume(). Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-24[SPARC64]: Use trap type stored in pt_regs to handle syscall restart.David S. Miller
Now that we can check the trap type directly, we don't need the funny restart_syscall indication from the trap return paths. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-23[SPARC64]: Store magic cookie and trap type in pt_regs.David S. Miller
This sets us up for several simplifications and facilities: 1) The magic cookie lets us identify trap frames more accurately in stack backtraces. 2) The trap type lets us simplify all of the "are we in a syscall" state management and checks. 3) We can now see if a task off the cpu is sleeping in a system call or not. In fact, we can see what trap it is sleeping in whatever the type. The utrace guys will use this. Based upon some discussions with Roland McGrath. Signed-off-by: David S. Miller <davem@davemloft.net>