GNU's addr2line can have problems parsing a vmlinux built with LLVM, particularly when LTO was used. In order to decode the traces correctly this patch adds the ability to switch to LLVM's utilities readelf and addr2line. The same approach is followed by Will in [1]. Before: $ scripts/decode_stacktrace.sh vmlinux < kernel.log [17716.240635] Call trace: [17716.240646] skb_cow_data (??:?) [17716.240654] esp6_input (ld-temp.o:?) [17716.240666] xfrm_input (ld-temp.o:?) [17716.240674] xfrm6_rcv (??:?) [...] After: $ LLVM=1 scripts/decode_stacktrace.sh vmlinux < kernel.log [17716.240635] Call trace: [17716.240646] skb_cow_data (include/linux/skbuff.h:2172 net/core/skbuff.c:4503) [17716.240654] esp6_input (net/ipv6/esp6.c:977) [17716.240666] xfrm_input (net/xfrm/xfrm_input.c:659) [17716.240674] xfrm6_rcv (net/ipv6/xfrm6_input.c:172) [...] Note that one could set CROSS_COMPILE=llvm- instead to hack around this issue. However, doing so can break the decodecode routine as it will force the selection of other LLVM utilities down the line e.g. llvm-as. [1] https://lore.kernel.org/all/20230914131225.13415-3-will@kernel.org/
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| @@ -16,6 +16,21 @@ elif type c++filt >/dev/null 2>&1 ; then · 15 unmodified lines | ||
| 16 | 16 | cppfilt_opts=-i |
| 17 | 17 | fi |
| 18 | 18 | |
| 19 | +UTIL_SUFFIX= | |
| 20 | +if [[ -z ${LLVM:-} ]]; then | |
| 21 | + UTIL_PREFIX=${CROSS_COMPILE:-} | |
| 22 | +else | |
| 23 | + UTIL_PREFIX=llvm- | |
| 24 | + if [[ ${LLVM} == */ ]]; then | |
| 25 | + UTIL_PREFIX=${LLVM}${UTIL_PREFIX} | |
| 26 | + elif [[ ${LLVM} == -* ]]; then | |
| 27 | + UTIL_SUFFIX=${LLVM} | |
| 28 | + fi | |
| 29 | +fi | |
| 30 | + | |
| 31 | +READELF=${UTIL_PREFIX}readelf${UTIL_SUFFIX} | |
| 32 | +ADDR2LINE=${UTIL_PREFIX}addr2line${UTIL_SUFFIX} | |
| 33 | + | |
| 19 | 34 | if [[ $1 == "-r" ]] ; then |
| 20 | 35 | vmlinux="" |
| 21 | 36 | basepath="auto" |
| @@ -75,7 +90,7 @@ find_module() { · 53 unmodified lines | ||
| 75 | 90 | |
| 76 | 91 | if [[ "$modpath" != "" ]] ; then |
| 77 | 92 | for fn in $(find "$modpath" -name "${module//_/[-_]}.ko*") ; do |
| 78 | − if readelf -WS "$fn" | grep -qwF .debug_line ; then | |
| 93 | + if ${READELF} -WS "$fn" | grep -qwF .debug_line ; then | |
| 79 | 94 | echo $fn |
| 80 | 95 | return |
| 81 | 96 | fi |
| @@ -169,7 +184,7 @@ parse_symbol() { · 87 unmodified lines | ||
| 169 | 184 | if [[ $aarray_support == true && "${cache[$module,$address]+isset}" == "isset" ]]; then |
| 170 | 185 | local code=${cache[$module,$address]} |
| 171 | 186 | else |
| 172 | − local code=$(${CROSS_COMPILE}addr2line -i -e "$objfile" "$address" 2>/dev/null) | |
| 187 | + local code=$(${ADDR2LINE} -i -e "$objfile" "$address" 2>/dev/null) | |
| 173 | 188 | if [[ $aarray_support == true ]]; then |
| 174 | 189 | cache[$module,$address]=$code |
| 175 | 190 | fi |