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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2011-10-07 13:36:40 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2011-12-09 08:55:44 -0800
commitb11ee9e9403ab72d52c46cc8b3b94de17ed196e6 (patch)
tree995af2d7d6d501591cc1770a2a8816ed38e155ea
parent400b14179e4170817aa476a29e29514c53bf4e25 (diff)
perf/x86: Fix PEBS instruction unwind
commit 57d1c0c03c6b48b2b96870d831b9ce6b917f53ac upstream. 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> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-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 1b1ef3addcf..3213c52db76 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -508,6 +508,7 @@ 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
@@ -559,7 +560,10 @@ 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);