diff options
| author | Adrian Hunter <adrian.hunter@intel.com> | 2023-01-31 14:16:22 +0100 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2023-02-02 01:51:31 +0100 |
| commit | 60fbb3e49abe8421b677d5eee32fe7fb27b05e3b (patch) | |
| tree | 50a633898fb7d4ad59c5922bf09ab032f46aed9b /tools/perf/util/symbol-elf.c | |
| parent | perf symbols: Add support for IFUNC symbols for x86_64 (diff) | |
| download | linux-60fbb3e49abe8421b677d5eee32fe7fb27b05e3b.tar.xz linux-60fbb3e49abe8421b677d5eee32fe7fb27b05e3b.zip | |
perf symbols: Allow for .plt without header
A static executable can have a .plt due to the presence of IFUNCs. In
that case the .plt does not have a header. Check for whether there is a
header by comparing the number of entries to the number of relocation
entries.
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230131131625.6964-7-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/symbol-elf.c')
| -rw-r--r-- | tools/perf/util/symbol-elf.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index a002fc0bea03..8f7802097c72 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -489,6 +489,7 @@ int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss) Elf *elf; int nr = 0, err = -1; struct rel_info ri = { .is_rela = false }; + bool lazy_plt; elf = ss->elf; ehdr = ss->ehdr; @@ -523,8 +524,10 @@ int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss) plt_sym->end = plt_sym->start + shdr_plt.sh_size; /* Use .plt.sec offset */ plt_offset = plt_sec_shdr.sh_offset; + lazy_plt = false; } else { - plt_offset = shdr_plt.sh_offset + plt_header_size; + plt_offset = shdr_plt.sh_offset; + lazy_plt = true; } scn_dynsym = ss->dynsym; @@ -577,6 +580,17 @@ int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss) ri.is_rela = shdr_rel_plt.sh_type == SHT_RELA; + if (lazy_plt) { + /* + * Assume a .plt with the same number of entries as the number + * of relocation entries is not lazy and does not have a header. + */ + if (ri.nr_entries * plt_entry_size == shdr_plt.sh_size) + dso__delete_symbol(dso, plt_sym); + else + plt_offset += plt_header_size; + } + /* * x86 doesn't insert IFUNC relocations in .plt order, so sort to get * back in order. |