Merge tag 'probes-fixes-v7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes fix from Masami Hiramatsu:

 - Convert ELF entry point to file offset in uprobe test

   Convert the ELF entry point address (e_entry) to a file offset using
   LOAD segment headers in add_remove_uprobe test. This fixes uprobe
   registration failures (-EINVAL) on non-PIE executables where vaddr
   exceeds file size.

* tag 'probes-fixes-v7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  selftests/ftrace: Convert ELF entry point to file offset in uprobe test
This commit is contained in:
Linus Torvalds
2026-08-11 06:51:46 -07:00

View File

@@ -12,9 +12,32 @@ echo 0 > events/enable
echo > dynamic_events
REALBIN=`readlink -f /bin/sh`
ENTRYPOINT=`readelf -h ${REALBIN} | grep Entry | sed -e 's/[^0]*//'`
echo "p:myevent ${REALBIN}:${ENTRYPOINT}" >> uprobe_events
# Get the entry point virtual address from ELF header
ENTRY=`readelf -hW ${REALBIN} | grep "Entry point" | awk '{print $NF}'`
# Convert virtual address to file offset: find the LOAD segment containing
# the entry point, then compute file_offset = e_entry - p_vaddr + p_offset.
# For PIE binaries this is a no-op (vaddr == file offset), but for non-PIE
# executables the virtual address is much larger than the file size and
# must be converted, otherwise uprobe_register() rejects it with -EINVAL.
ENTRY_DEC=$(printf '%d' "$ENTRY")
OFFSET=$ENTRY
while IFS= read -r line; do
set -- $line
[ "$1" = "LOAD" ] || continue
VA_DEC=$(printf '%d' "$3")
OFF_DEC=$(printf '%d' "$2")
FSZ_DEC=$(printf '%d' "$5")
if [ "$ENTRY_DEC" -ge "$VA_DEC" ] && [ "$ENTRY_DEC" -lt "$((VA_DEC + FSZ_DEC))" ]; then
OFFSET=$(printf '0x%x' "$((ENTRY_DEC - VA_DEC + OFF_DEC))")
break
fi
done << EOF
$(readelf -lW ${REALBIN} | grep LOAD)
EOF
echo "p:myevent ${REALBIN}:${OFFSET}" >> uprobe_events
grep -q myevent uprobe_events
test -d events/uprobes/myevent