From d2930ede5218be28413a00130a6895d14393c325 Mon Sep 17 00:00:00 2001 From: Remi Bernon Date: Thu, 9 Sep 2021 21:26:36 +0200 Subject: [PATCH] perf symbol: Look for ImageBase in PE file to compute .text offset 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 Fixes: 00a3423492bc90be ("perf symbols: Make dso__load_bfd_symbols() load PE files from debug cache only") Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Nicholas Fraser Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20210909192637.4139125-1-rbernon@codeweavers.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/symbol.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 77fc46ca07c0..0fc9a5410739 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -1581,10 +1581,6 @@ int dso__load_bfd_symbols(struct dso *dso, const char *debugfile) 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 *dso, const char *debugfile) 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