On 16 January 2014 12:56, Will Deacon will.deacon@arm.com wrote:
Hi Jean,
On Thu, Jan 16, 2014 at 10:45:23AM +0000, Jean Pihet wrote:
Add support for unwinding using the dwarf information in compat mode. Using the correct user stack pointer allows perf to record the frames correctly in the native and compat modes.
Note that although the dwarf frame unwinding works ok using libunwind in native mode (on ARMv7 & ARMv8), some changes are required to the libunwind code for the compat mode. Those changes are posted separately on the libunwind mailing list.
Tested on ARMv8 platform with v8 and compat v7 binaries, the latter are statically built.
I guess it makes sense to include this with your earlier series adding support for compat backtracing?
Signed-off-by: Jean Pihet jean.pihet@linaro.org
arch/arm64/include/asm/ptrace.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h index fbb0020..86d5b54 100644 --- a/arch/arm64/include/asm/ptrace.h +++ b/arch/arm64/include/asm/ptrace.h @@ -133,7 +133,7 @@ struct pt_regs { (!((regs)->pstate & PSR_F_BIT))
#define user_stack_pointer(regs) \
((regs)->sp)
(!compat_user_mode(regs)) ? ((regs)->sp) : ((regs)->compat_sp)In your previous series, compat backtracing is actually split out into a separate function (compat_user_backtrace), so it would be more consistent to have a compat_user_stack_pointer macro, rather than add this check here.
Do you mean this change instead?
diff --git a/kernel/events/internal.h b/kernel/events/internal.h index 569b2187..9b88d2e 100644 --- a/kernel/events/internal.h +++ b/kernel/events/internal.h @@ -185,7 +185,8 @@ static inline bool arch_perf_have_user_stack_dump(void) return true; }
-#define perf_user_stack_pointer(regs) user_stack_pointer(regs) +#define perf_user_stack_pointer(regs) \ + (!compat_user_mode(regs)) ? ((regs)->sp) : ((regs)->compat_sp) #else static inline bool arch_perf_have_user_stack_dump(void) {
If so let me prepare/test and re-submit this.
Thx! Jean
Will