forked from luck/tmp_suning_uos_patched
5331d7b846
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>
48 lines
1.0 KiB
C
48 lines
1.0 KiB
C
/*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
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*/
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#ifndef DUMPSTACK_H
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#define DUMPSTACK_H
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#ifdef CONFIG_X86_32
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#define STACKSLOTS_PER_LINE 8
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#define get_bp(bp) asm("movl %%ebp, %0" : "=r" (bp) :)
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#else
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#define STACKSLOTS_PER_LINE 4
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#define get_bp(bp) asm("movq %%rbp, %0" : "=r" (bp) :)
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#endif
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extern void
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show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
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unsigned long *stack, unsigned long bp, char *log_lvl);
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extern void
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show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
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unsigned long *sp, unsigned long bp, char *log_lvl);
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extern unsigned int code_bytes;
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/* The form of the top of the frame on the stack */
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struct stack_frame {
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struct stack_frame *next_frame;
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unsigned long return_address;
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};
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static inline unsigned long rewind_frame_pointer(int n)
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{
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struct stack_frame *frame;
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get_bp(frame);
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#ifdef CONFIG_FRAME_POINTER
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while (n--)
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frame = frame->next_frame;
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#endif
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return (unsigned long)frame;
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}
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#endif /* DUMPSTACK_H */
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