scripts/decode_stacktrace.sh: guess path to modules

Try to find module in directory with vmlinux (for fresh build). Then try standard paths where debuginfo are usually placed. Pick first file which have elf section '.debug_line'. Before: $ echo 'tap_open+0x0/0x0 [tap]' | ./scripts/decode_stacktrace.sh /usr/lib/debug/boot/vmlinux-5.4.0-37-generic WARNING! Modules path isn't set, but is needed to parse this symbol tap_open+0x0/0x0 tap After: $ echo 'tap_open+0x0/0x0 [tap]' | ./scripts/decode_stacktrace.sh /usr/lib/debug/boot/vmlinux-5.4.0-37-generic tap_open (drivers/net/tap.c:502) tap Signed-off-by: Konstantin Khlebnikov <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Cc: Sasha Levin <[email protected]> Link: http://lkml.kernel.org/r/159282923068.248444.5461337458421616083.stgit@buzz Signed-off-by: Linus Torvalds <[email protected]>
ambv · Aug 7, 2020 · 431151b · 431151b
1 parent ecda6e2
commit 431151b
Showing 1 changed file with 33 additions and 3 deletions.
diff --git a/scripts/decode_stacktrace.sh b/scripts/decode_stacktrace.sh
@@ -12,9 +12,40 @@ fi
 vmlinux=$1
 basepath=${2-auto}
 modpath=$3
+release=""
+
 declare -A cache
 declare -A modcache
 
+find_module() {
+	if [[ "$modpath" != "" ]] ; then
+		for fn in $(find "$modpath" -name "${module//_/[-_]}.ko*") ; do
+			if readelf -WS "$fn" | grep -qwF .debug_line ; then
+				echo $fn
+				return
+			fi
+		done
+		return 1
+	fi
+
+	modpath=$(dirname "$vmlinux")
+	find_module && return
+
+	if [[ $release == "" ]] ; then
+		release=$(gdb -ex 'print init_uts_ns.name.release' -ex 'quit' -quiet -batch "$vmlinux" | sed -n 's/\$1 = "\(.*\)".*/\1/p')
+	fi
+
+	for dn in {/usr/lib/debug,}/lib/modules/$release ; do
+		if [ -e "$dn" ] ; then
+			modpath="$dn"
+			find_module && return
+		fi
+	done
+
+	modpath=""
+	return 1
+}
+
 parse_symbol() {
 	# The structure of symbol at this point is:
 	#   ([name]+[offset]/[total length])
@@ -27,12 +58,11 @@ parse_symbol() {
 	elif [[ "${modcache[$module]+isset}" == "isset" ]]; then
 		local objfile=${modcache[$module]}
 	else
-		if [[ $modpath == "" ]]; then
+		local objfile=$(find_module)
+		if [[ $objfile == "" ]] ; then
 			echo "WARNING! Modules path isn't set, but is needed to parse this symbol" >&2
 			return
 		fi
-		local objfile=$(find "$modpath" -name "${module//_/[-_]}.ko*" -print -quit)
-		[[ $objfile == "" ]] && return
 		modcache[$module]=$objfile
 	fi