This is a note to let you know that I've just added the patch titled
perf symbol: Look for ImageBase in PE file to compute .text offset
to the 5.14-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:
perf-symbol-look-for-imagebase-in-pe-file-to-compute-.text-offset.patch
and it can be found in the queue-5.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From d2930ede5218be28413a00130a6895d14393c325 Mon Sep 17 00:00:00 2001
From: Remi Bernon <rbernon@xxxxxxxxxxxxxxx>
Date: Thu, 9 Sep 2021 21:26:36 +0200
Subject: perf symbol: Look for ImageBase in PE file to compute .text offset
From: Remi Bernon <rbernon@xxxxxxxxxxxxxxx>
commit d2930ede5218be28413a00130a6895d14393c325 upstream.
Instead of using the file offset in the debug file.
This fixes a regression from 00a3423492bc90be ("perf symbols: Make
dso__load_bfd_symbols() load PE files from debug cache only"), causing
incorrect symbol resolution when debug file have been stripped from
non-debug sections (in which case its .text section is empty and doesn't
have any file position).
The debug files could also be created with a different file alignment,
and have different file positions from the mmap-ed binary, or have the
section reordered.
This instead looks for the file image base, using the corresponding bfd
*ABS* symbols. As PE symbols only have 4 bytes, it also needs to keep
.text section vma high bits.
Signed-off-by: Remi Bernon <rbernon@xxxxxxxxxxxxxxx>
Fixes: 00a3423492bc90be ("perf symbols: Make dso__load_bfd_symbols() load PE files from debug cache only")
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Nicholas Fraser <nfraser@xxxxxxxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lore.kernel.org/lkml/20210909192637.4139125-1-rbernon@xxxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/perf/util/symbol.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1581,10 +1581,6 @@ int dso__load_bfd_symbols(struct dso *ds
if (bfd_get_flavour(abfd) == bfd_target_elf_flavour)
goto out_close;
- section = bfd_get_section_by_name(abfd, ".text");
- if (section)
- dso->text_offset = section->vma - section->filepos;
-
symbols_size = bfd_get_symtab_upper_bound(abfd);
if (symbols_size == 0) {
bfd_close(abfd);
@@ -1602,6 +1598,22 @@ int dso__load_bfd_symbols(struct dso *ds
if (symbols_count < 0)
goto out_free;
+ section = bfd_get_section_by_name(abfd, ".text");
+ if (section) {
+ for (i = 0; i < symbols_count; ++i) {
+ if (!strcmp(bfd_asymbol_name(symbols[i]), "__ImageBase") ||
+ !strcmp(bfd_asymbol_name(symbols[i]), "__image_base__"))
+ break;
+ }
+ if (i < symbols_count) {
+ /* PE symbols can only have 4 bytes, so use .text high bits */
+ dso->text_offset = section->vma - (u32)section->vma;
+ dso->text_offset += (u32)bfd_asymbol_value(symbols[i]);
+ } else {
+ dso->text_offset = section->vma - section->filepos;
+ }
+ }
+
qsort(symbols, symbols_count, sizeof(asymbol *), bfd_symbols__cmpvalue);
#ifdef bfd_get_section
Patches currently in stable-queue which might be from rbernon@xxxxxxxxxxxxxxx are
queue-5.14/perf-symbol-look-for-imagebase-in-pe-file-to-compute-.text-offset.patch
