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linux/arch/x86/kernel/dumpstack.h

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x86: unify appropriate bits from dumpstack_32 and dumpstack_64 Impact: cleanup As promised, now that dumpstack_32 and dumpstack_64 have so many bits in common, we should merge the in-sync bits into a common file, to prevent them from diverging again. This patch removes bits which are common between dumpstack_32.c and dumpstack_64.c and places them in a common dumpstack.c which is built for both 32 and 64 bit arches. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Alexander van Heukelum <heukelum@fastmail.fm> Signed-off-by: Ingo Molnar <mingo@elte.hu> Makefile | 2 arch/x86/kernel/Makefile | 2 arch/x86/kernel/Makefile | 2 arch/x86/kernel/Makefile | 2 arch/x86/kernel/Makefile | 2 arch/x86/kernel/Makefile | 2 arch/x86/kernel/dumpstack.c | 319 +++++++++++++++++++++++++++++++++++++++++ arch/x86/kernel/dumpstack.h | 39 +++++ arch/x86/kernel/dumpstack_32.c | 294 ------------------------------------- arch/x86/kernel/dumpstack_64.c | 285 ------------------------------------ 5 files changed, 363 insertions(+), 576 deletions(-)
2008-10-23 07:40:06 -07:00
/*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
*/
#ifndef DUMPSTACK_H
#define DUMPSTACK_H
#ifdef CONFIG_X86_32
#define STACKSLOTS_PER_LINE 8
#define get_bp(bp) asm("movl %%ebp, %0" : "=r" (bp) :)
#else
#define STACKSLOTS_PER_LINE 4
#define get_bp(bp) asm("movq %%rbp, %0" : "=r" (bp) :)
#endif
perf: Fix unsafe frame rewinding with hot regs fetching When we fetch the hot regs and rewind to the nth caller, it might happen that we dereference a frame pointer outside the kernel stack boundaries, like in this example: perf_trace_sched_switch+0xd5/0x120 schedule+0x6b5/0x860 retint_careful+0xd/0x21 Since we directly dereference a userspace frame pointer here while rewinding behind retint_careful, this may end up in a crash. Fix this by simply using probe_kernel_address() when we rewind the frame pointer. This issue will have a much more proper fix in the next version of the perf_arch_fetch_caller_regs() API that will only need to rewind to the first caller. Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Tested-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: David Miller <davem@davemloft.net> Cc: Archs <linux-arch@vger.kernel.org>
2010-04-08 05:05:50 -07:00
#include <linux/uaccess.h>
x86: unify appropriate bits from dumpstack_32 and dumpstack_64 Impact: cleanup As promised, now that dumpstack_32 and dumpstack_64 have so many bits in common, we should merge the in-sync bits into a common file, to prevent them from diverging again. This patch removes bits which are common between dumpstack_32.c and dumpstack_64.c and places them in a common dumpstack.c which is built for both 32 and 64 bit arches. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Alexander van Heukelum <heukelum@fastmail.fm> Signed-off-by: Ingo Molnar <mingo@elte.hu> Makefile | 2 arch/x86/kernel/Makefile | 2 arch/x86/kernel/Makefile | 2 arch/x86/kernel/Makefile | 2 arch/x86/kernel/Makefile | 2 arch/x86/kernel/Makefile | 2 arch/x86/kernel/dumpstack.c | 319 +++++++++++++++++++++++++++++++++++++++++ arch/x86/kernel/dumpstack.h | 39 +++++ arch/x86/kernel/dumpstack_32.c | 294 ------------------------------------- arch/x86/kernel/dumpstack_64.c | 285 ------------------------------------ 5 files changed, 363 insertions(+), 576 deletions(-)
2008-10-23 07:40:06 -07:00
extern void
show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
unsigned long *stack, unsigned long bp, char *log_lvl);
extern void
show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
unsigned long *sp, unsigned long bp, char *log_lvl);
extern unsigned int code_bytes;
/* The form of the top of the frame on the stack */
struct stack_frame {
struct stack_frame *next_frame;
unsigned long return_address;
};
perf: Introduce new perf_fetch_caller_regs() for hot regs snapshot Events that trigger overflows by interrupting a context can use get_irq_regs() or task_pt_regs() to retrieve the state when the event triggered. But this is not the case for some other class of events like trace events as tracepoints are executed in the same context than the code that triggered the event. It means we need a different api to capture the regs there, namely we need a hot snapshot to get the most important informations for perf: the instruction pointer to get the event origin, the frame pointer for the callchain, the code segment for user_mode() tests (we always use __KERNEL_CS as trace events always occur from the kernel) and the eflags for further purposes. v2: rename perf_save_regs to perf_fetch_caller_regs as per Masami's suggestion. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Archs <linux-arch@vger.kernel.org>
2010-03-04 13:15:56 -07:00
perf, x86: Fix callgraphs of 32-bit processes on 64-bit kernels When profiling a 32-bit process on a 64-bit kernel, callgraph tracing stopped after the first function, because it has seen a garbage memory address (tried to interpret the frame pointer, and return address as a 64-bit pointer). Fix this by using a struct stack_frame with 32-bit pointers when the TIF_IA32 flag is set. Note that TIF_IA32 flag must be used, and not is_compat_task(), because the latter is only set when the 32-bit process is executing a syscall, which may not always be the case (when tracing page fault events for example). Signed-off-by: Török Edwin <edwintorok@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Paul Mackerras <paulus@samba.org> Cc: x86@kernel.org Cc: linux-kernel@vger.kernel.org LKML-Reference: <1268820436-13145-1-git-send-email-edwintorok@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-17 03:07:16 -07:00
struct stack_frame_ia32 {
u32 next_frame;
u32 return_address;
};
perf: Introduce new perf_fetch_caller_regs() for hot regs snapshot Events that trigger overflows by interrupting a context can use get_irq_regs() or task_pt_regs() to retrieve the state when the event triggered. But this is not the case for some other class of events like trace events as tracepoints are executed in the same context than the code that triggered the event. It means we need a different api to capture the regs there, namely we need a hot snapshot to get the most important informations for perf: the instruction pointer to get the event origin, the frame pointer for the callchain, the code segment for user_mode() tests (we always use __KERNEL_CS as trace events always occur from the kernel) and the eflags for further purposes. v2: rename perf_save_regs to perf_fetch_caller_regs as per Masami's suggestion. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Archs <linux-arch@vger.kernel.org>
2010-03-04 13:15:56 -07:00
static inline unsigned long rewind_frame_pointer(int n)
{
struct stack_frame *frame;
get_bp(frame);
#ifdef CONFIG_FRAME_POINTER
perf: Fix unsafe frame rewinding with hot regs fetching When we fetch the hot regs and rewind to the nth caller, it might happen that we dereference a frame pointer outside the kernel stack boundaries, like in this example: perf_trace_sched_switch+0xd5/0x120 schedule+0x6b5/0x860 retint_careful+0xd/0x21 Since we directly dereference a userspace frame pointer here while rewinding behind retint_careful, this may end up in a crash. Fix this by simply using probe_kernel_address() when we rewind the frame pointer. This issue will have a much more proper fix in the next version of the perf_arch_fetch_caller_regs() API that will only need to rewind to the first caller. Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Tested-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: David Miller <davem@davemloft.net> Cc: Archs <linux-arch@vger.kernel.org>
2010-04-08 05:05:50 -07:00
while (n--) {
if (probe_kernel_address(&frame->next_frame, frame))
break;
}
x86: unify appropriate bits from dumpstack_32 and dumpstack_64 Impact: cleanup As promised, now that dumpstack_32 and dumpstack_64 have so many bits in common, we should merge the in-sync bits into a common file, to prevent them from diverging again. This patch removes bits which are common between dumpstack_32.c and dumpstack_64.c and places them in a common dumpstack.c which is built for both 32 and 64 bit arches. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Alexander van Heukelum <heukelum@fastmail.fm> Signed-off-by: Ingo Molnar <mingo@elte.hu> Makefile | 2 arch/x86/kernel/Makefile | 2 arch/x86/kernel/Makefile | 2 arch/x86/kernel/Makefile | 2 arch/x86/kernel/Makefile | 2 arch/x86/kernel/Makefile | 2 arch/x86/kernel/dumpstack.c | 319 +++++++++++++++++++++++++++++++++++++++++ arch/x86/kernel/dumpstack.h | 39 +++++ arch/x86/kernel/dumpstack_32.c | 294 ------------------------------------- arch/x86/kernel/dumpstack_64.c | 285 ------------------------------------ 5 files changed, 363 insertions(+), 576 deletions(-)
2008-10-23 07:40:06 -07:00
#endif
perf: Introduce new perf_fetch_caller_regs() for hot regs snapshot Events that trigger overflows by interrupting a context can use get_irq_regs() or task_pt_regs() to retrieve the state when the event triggered. But this is not the case for some other class of events like trace events as tracepoints are executed in the same context than the code that triggered the event. It means we need a different api to capture the regs there, namely we need a hot snapshot to get the most important informations for perf: the instruction pointer to get the event origin, the frame pointer for the callchain, the code segment for user_mode() tests (we always use __KERNEL_CS as trace events always occur from the kernel) and the eflags for further purposes. v2: rename perf_save_regs to perf_fetch_caller_regs as per Masami's suggestion. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Archs <linux-arch@vger.kernel.org>
2010-03-04 13:15:56 -07:00
return (unsigned long)frame;
}
#endif /* DUMPSTACK_H */
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