[PATCH] scripts/decode_stacktrace.sh: handle symbols in modules

From: Konstantin Khlebnikov
Date: Sat Apr 23 2016 - 15:04:11 EST


Add third argument: path where script looks for file module.ko when
decode module symbol "func+0x0ff/0x5153 [module]" into something like
"func (foo/bar.c:123) module". Without argument or if file isn't found
script prints such symbols as is without decoding.

Signed-off-by: Konstantin Khlebnikov <koct9i@xxxxxxxxx>
---
scripts/decode_stacktrace.sh | 55 ++++++++++++++++++++++++++++++------------
1 file changed, 39 insertions(+), 16 deletions(-)

diff --git a/scripts/decode_stacktrace.sh b/scripts/decode_stacktrace.sh
index 00d6d53c2681..c332684e1b5a 100755
--- a/scripts/decode_stacktrace.sh
+++ b/scripts/decode_stacktrace.sh
@@ -2,15 +2,17 @@
# (c) 2014, Sasha Levin <sasha.levin@xxxxxxxxxx>
#set -x

-if [[ $# != 2 ]]; then
+if [[ $# < 2 ]]; then
echo "Usage:"
- echo " $0 [vmlinux] [base path]"
+ echo " $0 [vmlinux] [base path] [modules path]"
exit 1
fi

vmlinux=$1
basepath=$2
+modpath=$3
declare -A cache
+declare -A modcache

parse_symbol() {
# The structure of symbol at this point is:
@@ -19,6 +21,17 @@ parse_symbol() {
# For example:
# do_basic_setup+0x9c/0xbf

+ if [[ $module == "" ]] ; then
+ local objfile=$vmlinux
+ elif [[ "${modcache[$module]+isset}" == "isset" ]]; then
+ local objfile=${modcache[$module]}
+ else
+ [[ $modpath == "" ]] && return
+ local objfile=$(find "$modpath" -name $module.ko -print -quit)
+ [[ $objfile == "" ]] && return
+ modcache[$module]=$objfile
+ fi
+
# Remove the englobing parenthesis
symbol=${symbol#\(}
symbol=${symbol%\)}
@@ -29,11 +42,11 @@ parse_symbol() {
# Use 'nm vmlinux' to figure out the base address of said symbol.
# It's actually faster to call it every time than to load it
# all into bash.
- if [[ "${cache[$name]+isset}" == "isset" ]]; then
- local base_addr=${cache[$name]}
+ if [[ "${cache[$module,$name]+isset}" == "isset" ]]; then
+ local base_addr=${cache[$module,$name]}
else
- local base_addr=$(nm "$vmlinux" | grep -i ' t ' | awk "/ $name\$/ {print \$1}" | head -n1)
- cache["$name"]="$base_addr"
+ local base_addr=$(nm "$objfile" | grep -i ' t ' | awk "/ $name\$/ {print \$1}" | head -n1)
+ cache[$module,$name]="$base_addr"
fi
# Let's start doing the math to get the exact address into the
# symbol. First, strip out the symbol total length.
@@ -48,12 +61,12 @@ parse_symbol() {
local address=$(printf "%x\n" "$expr")

# Pass it to addr2line to get filename and line number
- # Could get more than one result
- if [[ "${cache[$address]+isset}" == "isset" ]]; then
- local code=${cache[$address]}
+ # Could get more than one result
+ if [[ "${cache[$module,$address]+isset}" == "isset" ]]; then
+ local code=${cache[$module,$address]}
else
- local code=$(addr2line -i -e "$vmlinux" "$address")
- cache[$address]=$code
+ local code=$(addr2line -i -e "$objfile" "$address")
+ cache[$module,$address]=$code
fi

# addr2line doesn't return a proper error code if it fails, so
@@ -105,13 +118,23 @@ handle_line() {
fi
done

- # The symbol is the last element, process it
- symbol=${words[$last]}
+ if [[ ${words[$last]} =~ \[([^]]+)\] ]]; then
+ module=${words[$last]}
+ module=${module#\[}
+ module=${module%\]}
+ symbol=${words[$last-1]}
+ unset words[$last-1]
+ else
+ # The symbol is the last element, process it
+ symbol=${words[$last]}
+ module=
+ fi
+
unset words[$last]
parse_symbol # modifies $symbol

# Add up the line number to the symbol
- echo "${words[@]}" "$symbol"
+ echo "${words[@]}" "$symbol $module"
}

while read line; do
@@ -121,8 +144,8 @@ while read line; do
handle_line "$line"
# Is it a code line?
elif [[ $line == *Code:* ]]; then
- decode_code "$line"
- else
+ decode_code "$line"
+ else
# Nothing special in this line, show it as is
echo "$line"
fi