Andy Lutomirski
2016-04-14 18:32:07 UTC
We can use user_64bit_mode(regs) here instead of thread flag
because we have full register frame.
---
arch/x86/events/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 041e442a3e28..91d101a9a6e9 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2269,7 +2269,7 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)
struct stack_frame_ia32 frame;
const void __user *fp;
- if (!test_thread_flag(TIF_IA32))
+ if (user_64bit_mode(regs))
return 0;
Peter, I got lost in the code that calls this. Are regs coming frombecause we have full register frame.
---
arch/x86/events/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 041e442a3e28..91d101a9a6e9 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2269,7 +2269,7 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)
struct stack_frame_ia32 frame;
const void __user *fp;
- if (!test_thread_flag(TIF_IA32))
+ if (user_64bit_mode(regs))
return 0;
the overflow interrupt's regs, current_pt_regs(), or
perf_get_regs_user?
If it's the perf_get_regs_user, then this should be okay, but passing
in the ABI field directly would be even nicer. If they're coming from
the overflow interrupt's regs or current_pt_regs(), could we change
that?
It might also be nice to make sure that we call perf_get_regs_user
exactly once per overflow interrupt -- i.e. we could push it into the
main code rather than the regs sampling code.
cs_base = get_segment_base(regs->cs);
--
2.8.0
--
2.8.0
--
Andy Lutomirski
AMA Capital Management, LLC
Andy Lutomirski
AMA Capital Management, LLC