This is a note to let you know that I've just added the patch titled
Revert "scripts/faddr2line: Check only two symbols when calculating symbol size"
to the 6.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
revert-scripts-faddr2line-check-only-two-symbols-whe.patch
and it can be found in the queue-6.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d0c6c081d693523d62647a63de94b11992b491df
Author: Carlos Llamas <cmllamas@xxxxxxxxxx>
Date: Mon Aug 12 23:01:20 2024 +0000
Revert "scripts/faddr2line: Check only two symbols when calculating symbol size"
[ Upstream commit 56ac7bd2c58a4e93d19f0ccb181035d075b315d3 ]
This reverts commit c02904f05ff805d6c0631634d5751ebd338f75ec.
Such commit assumed that only two symbols are relevant for the symbol
size calculation. However, this can lead to an incorrect symbol size
calculation when there are mapping symbols emitted by readelf.
For instance, when feeding 'update_irq_load_avg+0x1c/0x1c4', faddr2line
might need to process the following readelf lines:
784284: ffffffc0081cca30 428 FUNC GLOBAL DEFAULT 2 update_irq_load_avg
87319: ffffffc0081ccb0c 0 NOTYPE LOCAL DEFAULT 2 $x.62522
87321: ffffffc0081ccbdc 0 NOTYPE LOCAL DEFAULT 2 $x.62524
87323: ffffffc0081ccbe0 0 NOTYPE LOCAL DEFAULT 2 $x.62526
87325: ffffffc0081ccbe4 0 NOTYPE LOCAL DEFAULT 2 $x.62528
87327: ffffffc0081ccbe8 0 NOTYPE LOCAL DEFAULT 2 $x.62530
87329: ffffffc0081ccbec 0 NOTYPE LOCAL DEFAULT 2 $x.62532
87331: ffffffc0081ccbf0 0 NOTYPE LOCAL DEFAULT 2 $x.62534
87332: ffffffc0081ccbf4 0 NOTYPE LOCAL DEFAULT 2 $x.62535
783403: ffffffc0081ccbf4 424 FUNC GLOBAL DEFAULT 2 sched_pelt_multiplier
The symbol size of 'update_irq_load_avg' should be calculated with the
address of 'sched_pelt_multiplier', after skipping the mapping symbols
seen in between. However, the offending commit cuts the list short and
faddr2line incorrectly assumes 'update_irq_load_avg' is the last symbol
in the section, resulting in:
$ scripts/faddr2line vmlinux update_irq_load_avg+0x1c/0x1c4
skipping update_irq_load_avg address at 0xffffffc0081cca4c due to size mismatch (0x1c4 != 0x3ff9a59988)
no match for update_irq_load_avg+0x1c/0x1c4
After reverting the commit the issue is resolved:
$ scripts/faddr2line vmlinux update_irq_load_avg+0x1c/0x1c4
update_irq_load_avg+0x1c/0x1c4:
cpu_of at kernel/sched/sched.h:1109
(inlined by) update_irq_load_avg at kernel/sched/pelt.c:481
Fixes: c02904f05ff8 ("scripts/faddr2line: Check only two symbols when calculating symbol size")
Signed-off-by: Carlos Llamas <cmllamas@xxxxxxxxxx>
Acked-by: Will Deacon <will@xxxxxxxxxx>
Acked-by: Brian Johannesmeyer <bjohannesmeyer@xxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/scripts/faddr2line b/scripts/faddr2line
index fe0cc45f03be1..1fa6beef9f978 100755
--- a/scripts/faddr2line
+++ b/scripts/faddr2line
@@ -252,7 +252,7 @@ __faddr2line() {
found=2
break
fi
- done < <(echo "${ELF_SYMS}" | sed 's/\[.*\]//' | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2 | ${GREP} -A1 --no-group-separator " ${sym_name}$")
+ done < <(echo "${ELF_SYMS}" | sed 's/\[.*\]//' | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2)
if [[ $found = 0 ]]; then
warn "can't find symbol: sym_name: $sym_name sym_sec: $sym_sec sym_addr: $sym_addr sym_elf_size: $sym_elf_size"
