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From: Xiong Nandi <xndchn@gmail.com>
To: akpm@linux-foundation.org
Cc: linux-kernel@vger.kernel.org,
	quic_bjorande@quicinc.com,
	cmllamas@google.com,
	quic_eberman@quicinc.com,
	Xiong Nandi <xndchn@gmail.com>
Subject: Re: [PATCH] scripts/decode_stacktrace.sh: better support to ARM32 module stack trace
Date: Wed, 22 May 2024 09:05:59 +0800
Message-Id: <20240522010559.10551-1-xndchn@gmail.com>
In-Reply-To: <20240521005649.12144-1-xndchn@gmail.com>
References: <20240521005649.12144-1-xndchn@gmail.com>
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Sorry about the name, it is some kind of abbreviation. So I re-post here:
---
Since System.map is generated by cross-compile nm tool, we should use it
here too. Otherwise host nm may not recognize thumb2 function address well.

Beside, sometimes special characters around module name, such as ARM32
with BACKTRACE_VERBOSE in "(%pS)" format, such as:
[<806e4845>] (dump_stack_lvl) from [<7f806013>] (hello_init+0x13/0x1000 [test])

After stripping other characters around "[module]", it can be finally decoded:
(dump_stack_lvl) from hello_init (/foo/test.c:10) test

Signed-off-by: Xiong Nandi <xndchn@gmail.com>
---
 scripts/decode_stacktrace.sh | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/scripts/decode_stacktrace.sh b/scripts/decode_stacktrace.sh
index fa5be6f57b00..324e4a6c260a 100755
--- a/scripts/decode_stacktrace.sh
+++ b/scripts/decode_stacktrace.sh
@@ -30,6 +30,7 @@ fi
 
 READELF=${UTIL_PREFIX}readelf${UTIL_SUFFIX}
 ADDR2LINE=${UTIL_PREFIX}addr2line${UTIL_SUFFIX}
+NM=${UTIL_PREFIX}nm${UTIL_SUFFIX}
 
 if [[ $1 == "-r" ]] ; then
 	vmlinux=""
@@ -158,7 +159,7 @@ parse_symbol() {
 	if [[ $aarray_support == true && "${cache[$module,$name]+isset}" == "isset" ]]; then
 		local base_addr=${cache[$module,$name]}
 	else
-		local base_addr=$(nm "$objfile" 2>/dev/null | awk '$3 == "'$name'" && ($2 == "t" || $2 == "T") {print $1; exit}')
+		local base_addr=$(${NM} "$objfile" 2>/dev/null | awk '$3 == "'$name'" && ($2 == "t" || $2 == "T") {print $1; exit}')
 		if [[ $base_addr == "" ]] ; then
 			# address not found
 			return
@@ -282,8 +283,8 @@ handle_line() {
 
 	if [[ ${words[$last]} =~ \[([^]]+)\] ]]; then
 		module=${words[$last]}
-		module=${module#\[}
-		module=${module%\]}
+		module=${module#*\[}
+		module=${module%\]*}
 		modbuildid=${module#* }
 		module=${module% *}
 		if [[ $modbuildid == $module ]]; then
-- 
2.25.1