[PATCH][V3] arm64: perf: Get the wrong PC value in REGS_ABI_32 mode

[Jiping Ma <jiping.ma2@windriver.com>]

Modified the patch subject and the change description.

PC value is get from regs[15] in REGS_ABI_32 mode, but correct PC
is regs->pc(regs[PERF_REG_ARM64_PC]) in arm64 kernel, which caused
that perf can not parser the backtrace of app with dwarf mode in the 
32bit system and 64bit kernel.

Signed-off-by: Jiping Ma <jiping.ma2@windriver.com>
---
 arch/arm64/kernel/perf_regs.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/kernel/perf_regs.c b/arch/arm64/kernel/perf_regs.c
index 0bbac61..0ef2880 100644
--- a/arch/arm64/kernel/perf_regs.c
+++ b/arch/arm64/kernel/perf_regs.c
@@ -32,6 +32,10 @@ u64 perf_reg_value(struct pt_regs *regs, int idx)
 	if ((u32)idx == PERF_REG_ARM64_PC)
 		return regs->pc;
 
+	if (perf_reg_abi(current) == PERF_SAMPLE_REGS_ABI_32
+		&& idx == 15)
+		return regs->pc;
+
 	return regs->regs[idx];
 }
 
-- 
1.9.1