[GIT PULL] probes: Fixes for v7.2-rc7

[Masami Hiramatsu (Google) <mhiramat@kernel.org>]

Hi Linus,

Probes fixes for v7.2-rc7:

- selftests/ftrace: 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.


Please pull the latest probes-fixes-v7.2-rc7 tree, which can be found at:


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

Tag SHA1: 4c8d7ffb75feb2123c2a69ad46bb3c77c2bc74b0
Head SHA1: 24aa630f6259e6a2107936c06fed72063f712b64


Rui Qi (1):
      selftests/ftrace: Convert ELF entry point to file offset in uprobe test

----
 .../ftrace/test.d/dynevent/add_remove_uprobe.tc    | 27 ++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)
---------------------------
commit 24aa630f6259e6a2107936c06fed72063f712b64
Author: Rui Qi <qirui.001@bytedance.com>
Date:   Fri Aug 7 16:15:12 2026 +0800

    selftests/ftrace: Convert ELF entry point to file offset in uprobe test
    
    The add_remove_uprobe test uses readelf -h to obtain the ELF entry
    point (e_entry) and passes it directly as the offset to uprobe_events.
    However, uprobe_events expects a file offset, not a virtual address.
    
    For PIE binaries, the virtual address happens to equal the file offset
    because the first LOAD segment has p_vaddr == p_offset, so the test
    works by coincidence. But for non-PIE executables, e_entry is an
    absolute virtual address that can far exceed the file size. When the
    probe is enabled, uprobe_register() checks offset > i_size_read(inode)
    and rejects it with -EINVAL.
    
    Fix this by converting the virtual address to a file offset using the
    ELF program headers: scan readelf -lW output for the LOAD segment
    containing the entry point, then compute file_offset = e_entry -
    p_vaddr + p_offset. For PIE binaries the result is unchanged; for
    non-PIE binaries the offset is correctly translated.
    
    The conversion uses only POSIX shell primitives, with no dependency on
    gawk or perl.
    
    Link: https://lore.kernel.org/all/20260807081512.2974757-3-qirui.001@bytedance.com/
    
    Fixes: dc4b165855f2 ("selftests/ftrace: Use readelf to find entry point in uprobe test")
    Cc: stable@vger.kernel.org
    Signed-off-by: Rui Qi <qirui.001@bytedance.com>
    Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_uprobe.tc b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_uprobe.tc
index f2048c244526..19430bd5864c 100644
--- a/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_uprobe.tc
+++ b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_uprobe.tc
@@ -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

-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>