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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2011-10-07 13:36:40 +0200
committerIngo Molnar <mingo@elte.hu>2011-11-14 13:01:20 +0100
commit57d1c0c03c6b48b2b96870d831b9ce6b917f53ac (patch)
tree80039cd44137c39e4ab400e642ee3751cb870f50
parent7f80850d3f9fd8fda23a317044aef3a6bafab06b (diff)
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perf/x86: Fix PEBS instruction unwind
Masami spotted that we always try to decode the instruction stream as 64bit instructions when running a 64bit kernel, this doesn't work for ia32-compat proglets. Use TIF_IA32 to detect if we need to use the 32bit instruction decoder. Reported-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: stable@kernel.org Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--arch/x86/kernel/cpu/perf_event_intel_ds.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index c0d238f..73da6b6 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -493,6 +493,7 @@ static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
unsigned long from = cpuc->lbr_entries[0].from;
unsigned long old_to, to = cpuc->lbr_entries[0].to;
unsigned long ip = regs->ip;
+ int is_64bit = 0;
/*
* We don't need to fixup if the PEBS assist is fault like
@@ -544,7 +545,10 @@ static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
} else
kaddr = (void *)to;
- kernel_insn_init(&insn, kaddr);
+#ifdef CONFIG_X86_64
+ is_64bit = kernel_ip(to) || !test_thread_flag(TIF_IA32);
+#endif
+ insn_init(&insn, kaddr, is_64bit);
insn_get_length(&insn);
to += insn.length;
} while (to < ip);