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2016-02-23s390/dumpstack: merge all four stack tracersHeiko Carstens1-62/+22
We have four different stack tracers of which three had bugs. So it's time to merge them to a single stack tracer which allows to specify a call back function which will be called for each step. This patch changes behavior a bit: - the "nosched" and "in_sched_functions" check within save_stack_trace_tsk did work only for the last stack frame within a context. Now it considers the check for each stack frame like it should. - both the oprofile variant and the perf_events variant did save a return address twice if a zero back chain was detected, which indicates an interrupt frame. The new dump_trace function will call the oprofile and perf_events backends with the psw address that is contained within the corresponding pt_regs structure instead. - the original show_trace and save_context_stack functions did already use the psw address of the pt_regs structure if a zero back chain was detected. However now we ignore the psw address if it is a user space address. After all we trace the kernel stack and not the user space stack. This way we also get rid of the garbage user space address in case of warnings and / or panic call traces. So this should make life easier since now there is only one stack tracer left which we can break. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-02-23s390: add current_stack_pointer() helper functionHeiko Carstens1-6/+3
Implement current_stack_pointer() helper function and use it everywhere, instead of having several different inline assembly variants. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-02-23s390/stacktrace: use nosched instead of savesched parameterHeiko Carstens1-6/+6
Use the inversed "nosched" logic like all other architectures. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-02-10s390/stacktrace: add save_stack_trace_regs()Pratyush Anand1-0/+11
Implement save_stack_trace_regs, so that a stack trace of a kprobe event can be obtained. Without this we see following warning: "save_stack_trace_regs() not implemented yet." when we execute: echo stacktrace > /sys/kernel/debug/tracing/trace_options echo "p kfree" >> /sys/kernel/debug/tracing/kprobe_events echo 1 > /sys/kernel/debug/tracing/events/kprobes/enable Reported-by: Chunyu Hu <chuhu@redhat.com> Signed-off-by: Pratyush Anand <panand@redhat.com> [heiko.carstens@de.ibm.com]: changed patch to use __save_stack_trace() Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-02-10s390/stacktrace: save full stack tracesHeiko Carstens1-9/+12
save_stack_trace() only saves the stack trace of the current context (interrupt or process context). This is different to what other architectures like x86 do, which save the full stack trace across different contexts. Also extract a __save_stack_trace() helper function which will be used by a follow on patch. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-02-10s390/stacktrace: add missing end markerHeiko Carstens1-0/+2
save_stack_trace() did not write the ULONG_MAX end marker if there is enough space left. So simply follow x86 and arm64. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-02-10s390/stacktrace: fix address ranges for asynchronous and panic stackHeiko Carstens1-5/+6
git commit dc7ee00d4771 ("s390: lowcore stack pointer offsets") introduced a regression in regard to save_stack_trace(). The stack pointer for the asynchronous and the panic stack in the lowcore now have an additional offset applied to them. This offset needs to be taken into account in the calculation for the low and high address for the stacks. This bug was already partially fixed with 9cc5c206d9b4 ("s390/dumpstack: fix address ranges for asynchronous and panic stack"). This patch fixes it also for the stacktrace code. Fixes: dc7ee00d4771 ("s390: lowcore stack pointer offsets") Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-02-10s390/stacktrace: fix save_stack_trace_tsk() for current taskHeiko Carstens1-0/+4
The function save_stack_trace_tsk() did not consider that it can be used for tsk == current, for which the current stack pointer obviously cannot be found in the thread structure. Fix this and get the stack pointer with an inline assembly. This fixes e.g. the output of "cat /proc/self/stack". Before: [<0000000000000000>] (null) [<ffffffffffffffff>] 0xffffffffffffffff After: [<000000000011b3ee>] save_stack_trace_tsk+0x56/0x98 [<0000000000366cde>] proc_pid_stack+0xae/0x108 [<00000000003636f0>] proc_single_show+0x70/0xc0 [<0000000000311fbc>] seq_read+0xcc/0x448 [<00000000002e7716>] __vfs_read+0x36/0x100 [<00000000002e872e>] vfs_read+0x76/0x130 [<00000000002e975e>] SyS_read+0x66/0xd8 [<000000000089490e>] system_call+0xd6/0x264 [<ffffffffffffffff>] 0xffffffffffffffff Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-01-19s390: remove all usages of PSW_ADDR_INSNHeiko Carstens1-6/+5
Yet another leftover from the 31 bit era. The usual operation "y = x & PSW_ADDR_INSN" with the PSW_ADDR_INSN mask is a nop for CONFIG_64BIT. Therefore remove all usages and hope the code is a bit less confusing. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
2012-07-20s390/comments: unify copyright messages and remove file namesHeiko Carstens1-3/+1
Remove the file name from the comment at top of many files. In most cases the file name was wrong anyway, so it's rather pointless. Also unify the IBM copyright statement. We did have a lot of sightly different statements and wanted to change them one after another whenever a file gets touched. However that never happened. Instead people start to take the old/"wrong" statements to use as a template for new files. So unify all of them in one go. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-17[S390] Fix stacktrace compile bug.Heiko Carstens1-0/+1
Add missing module.h include to fix this: CC arch/s390/kernel/stacktrace.o arch/s390/kernel/stacktrace.c:84: warning: data definition has no type or storage class arch/s390/kernel/stacktrace.c:84: warning: type defaults to 'int' in declaration of 'EXPORT_SYMBOL_GPL' arch/s390/kernel/stacktrace.c:84: warning: parameter names (without types) in function declaration arch/s390/kernel/stacktrace.c:97: warning: data definition has no type or storage class arch/s390/kernel/stacktrace.c:97: warning: type defaults to 'int' in declaration of 'EXPORT_SYMBOL_GPL' arch/s390/kernel/stacktrace.c:97: warning: parameter names (without types) in function declaration Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-03stacktrace: export save_stack_trace[_tsk]Ingo Molnar1-0/+2
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>
2008-02-05[S390] latencytop s390 support.Heiko Carstens1-8/+23
Cc: Holger Wolf <wolf@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-07-17[S390] Simplify stack trace.Heiko Carstens1-15/+11
sparse gives us a few of these: stacktrace.c:69:38: warning: incorrect type in argument 2 (different signedness) stacktrace.c:69:38: expected unsigned int *skip Just get rid of the 'skip' argument since it is contained in the struct stack_trace that gets passed anyway. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-05-08simplify the stacktrace codeChristoph Hellwig1-11/+7
Simplify the stacktrace code: - remove the unused task argument to save_stack_trace, it's always current - remove the all_contexts flag, it's alwasy 0 Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andi Kleen <ak@suse.de> Cc: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-05[S390] Avoid excessive inlining.Heiko Carstens1-5/+5
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-10-11[S390] stacktrace bug.Christian Borntraeger1-9/+8
The latest kernel 2.6.19-rc1 triggers a bug in the s390 specific stack trace code when compiled with gcc 3.4. This patch fixes the latest lock dependency validator code (2.6.19-rc1) on s390 gcc 3.4. The variable sp was fixed to r15 (which is the stack pointer in the s390 abi) and assigned new values to r15. Therefore, gcc 3.4 assigns a new value to r15 and does not restore it on exit (r15 is supposed to be call save) - the kernel stack is broken. Avoid trouble by not assigning any new value to sp (r15). Signed-off-by: Christian Borntraeger <cborntra@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-09-26[PATCH] x86: Some preparationary cleanup for stack traceAndi Kleen1-9/+8
- Remove unused all_contexts parameter No caller used it - Move skip argument into the structure (needed for followon patches) Cc: mingo@elte.hu Signed-off-by: Andi Kleen <ak@suse.de>
2006-07-03[PATCH] lockdep: stacktrace subsystem, s390 supportHeiko Carstens1-0/+90
stacktrace interface for s390 as needed by lock validator. [clg@fr.ibm.com: build fix] Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>