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From: Seung-Woo Kim <sw0312.kim@samsung.com>
To: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, will@kernel.org,
	mark.rutland@arm.com, catalin.marinas@arm.com
Cc: sw0312.kim@samsung.com, sungguk.na@samsung.com
Subject: [PATCH] arm64: perf: Report arm pc registers for compat perf
Date: Tue, 12 Nov 2019 10:01:41 +0900	[thread overview]
Message-ID: <1573520501-29195-1-git-send-email-sw0312.kim@samsung.com> (raw)
In-Reply-To: CGME20191112005902epcas1p2d9dfa6a29f2c57669b1c1eb58517016d@epcas1p2.samsung.com

If perf is built as arm 32-bit, it only reads 15 registers as arm
32-bit register map and this breaks dwarf call-chain in compat
perf because pc register information is not filled.
Report arm pc registers for 32-bit compat perf.

Without this, arm 32-bit perf dwarf call-graph shows below
verbose message:
  unwind: reg 15, val 0
  unwind: reg 13, val ffbc6360
  unwind: no map for 0

Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
---
 arch/arm64/kernel/perf_regs.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/arm64/kernel/perf_regs.c b/arch/arm64/kernel/perf_regs.c
index 0bbac61..d4172e7 100644
--- a/arch/arm64/kernel/perf_regs.c
+++ b/arch/arm64/kernel/perf_regs.c
@@ -24,6 +24,8 @@ u64 perf_reg_value(struct pt_regs *regs, int idx)
 			return regs->compat_sp;
 		if ((u32)idx == PERF_REG_ARM64_LR)
 			return regs->compat_lr;
+		if ((u32)idx == 15) /* PERF_REG_ARM_PC */
+			return regs->pc;
 	}
 
 	if ((u32)idx == PERF_REG_ARM64_SP)
-- 
1.7.4.1


       reply	other threads:[~2019-11-12  1:01 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20191112005902epcas1p2d9dfa6a29f2c57669b1c1eb58517016d@epcas1p2.samsung.com>
2019-11-12  1:01 ` Seung-Woo Kim [this message]
2019-11-12  9:40   ` [PATCH] arm64: perf: Report arm pc registers for compat perf Mark Rutland
2019-11-13  4:16     ` Seung-Woo Kim

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