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Commit 87f44bbc authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
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perf, trace: Fix !x86 build bug 



Patch b7e2ecef (perf, trace: Optimize tracepoints by removing
IRQ-disable from perf/tracepoint interaction) made the
unfortunate mistake of assuming the world is x86 only, correct
this.

The problem was that perf_fetch_caller_regs() did
local_save_flags() into regs->flags, and I re-used that to
remove another local_save_flags(), forgetting !x86 doesn't have
regs->flags.

Do the reverse, remove the local_save_flags() from
perf_fetch_caller_regs() and let the ftrace site do the
local_save_flags() instead.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: default avatarPaul Mackerras <paulus@samba.org>
Cc: acme@redhat.com
Cc: efault@gmx.de
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
LKML-Reference: <1274778175.5882.623.camel@twins>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent d67f088e

arch/x86/kernel/cpu/perf_event.c

+5 −1
Original line number Diff line number Diff line
@@ -1717,7 +1717,11 @@ void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int ski 
	 */

	regs->bp = rewind_frame_pointer(skip + 1);

	regs->cs = __KERNEL_CS;

	local_save_flags(regs->flags);

	/*

	 * We abuse bit 3 to pass exact information, see perf_misc_flags

	 * and the comment with PERF_EFLAGS_EXACT.

	 */

	regs->flags = 0;

}



unsigned long perf_instruction_pointer(struct pt_regs *regs)

kernel/trace/trace_event_perf.c

+3 −1
Original line number Diff line number Diff line
@@ -157,6 +157,7 @@ __kprobes void *perf_trace_buf_prepare(int size, unsigned short type, 
				       struct pt_regs *regs, int *rctxp)

{

	struct trace_entry *entry;

	unsigned long flags;

	char *raw_data;

	int pc;
@@ -174,7 +175,8 @@ __kprobes void *perf_trace_buf_prepare(int size, unsigned short type, 
	memset(&raw_data[size - sizeof(u64)], 0, sizeof(u64));



	entry = (struct trace_entry *)raw_data;

	tracing_generic_entry_update(entry, regs->flags, pc);

	local_save_flags(flags);

	tracing_generic_entry_update(entry, flags, pc);

	entry->type = type;



	return raw_data;