Messages in this thread Patch in this message | | | From | Rémi Bernon <> | Subject | [RFC PATCH 1/2] perf dso: Use libbfd to read build_id and .gnu_debuglink section | Date | Mon, 1 Jun 2020 13:19:14 +0200 |
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Wine generates PE binaries for most of its modules and perf is unable to parse these files to get build_id or .gnu_debuglink section.
Using libbfd when available, instead of libelf, makes it possible to resolve debug file location regardless of the dso binary format.
Signed-off-by: Rémi Bernon <rbernon@codeweavers.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jacek Caban <jacek@codeweavers.com> --- tools/perf/util/symbol-elf.c | 65 ++++++++++++++++++++++++++++++++++-- 1 file changed, 62 insertions(+), 3 deletions(-)
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index be5b493f8284..85bbc1ec9fe5 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -50,6 +50,10 @@ typedef Elf64_Nhdr GElf_Nhdr; #define DMGL_ANSI (1 << 1) /* Include const, volatile, etc */ #endif +#ifdef HAVE_LIBBFD_SUPPORT +#define PACKAGE 'perf' +#include <bfd.h> +#else #ifdef HAVE_CPLUS_DEMANGLE_SUPPORT extern char *cplus_demangle(const char *, int); @@ -65,9 +69,7 @@ static inline char *bfd_demangle(void __maybe_unused *v, { return NULL; } -#else -#define PACKAGE 'perf' -#include <bfd.h> +#endif #endif #endif @@ -532,6 +534,30 @@ static int elf_read_build_id(Elf *elf, void *bf, size_t size) int filename__read_build_id(const char *filename, void *bf, size_t size) { +#ifdef HAVE_LIBBFD_SUPPORT + int err = -1; + bfd *abfd; + + abfd = bfd_openr(filename, NULL); + if (!abfd) + return -1; + + if (!bfd_check_format(abfd, bfd_object)) { + pr_debug2("%s: cannot read %s bfd file.\n", __func__, filename); + goto out_close; + } + + if (!abfd->build_id || abfd->build_id->size > size) + goto out_close; + + memcpy(bf, abfd->build_id->data, abfd->build_id->size); + memset(bf + abfd->build_id->size, 0, size - abfd->build_id->size); + err = 0; + +out_close: + bfd_close(abfd); + return err; +#else int fd, err = -1; Elf *elf; @@ -555,6 +581,7 @@ int filename__read_build_id(const char *filename, void *bf, size_t size) close(fd); out: return err; +#endif } int sysfs__read_build_id(const char *filename, void *build_id, size_t size) @@ -611,6 +638,37 @@ int sysfs__read_build_id(const char *filename, void *build_id, size_t size) int filename__read_debuglink(const char *filename, char *debuglink, size_t size) { +#ifdef HAVE_LIBBFD_SUPPORT + int err = -1; + asection *section; + bfd *abfd; + + abfd = bfd_openr(filename, NULL); + if (!abfd) + return -1; + + if (!bfd_check_format(abfd, bfd_object)) { + pr_debug2("%s: cannot read %s bfd file.\n", __func__, filename); + goto out_close; + } + + section = bfd_get_section_by_name(abfd, ".gnu_debuglink"); + if (!section) + goto out_close; + + if (section->size > size) + goto out_close; + + if (!bfd_get_section_contents(abfd, section, debuglink, 0, + section->size)) + goto out_close; + + err = 0; + +out_close: + bfd_close(abfd); + return err; +#else int fd, err = -1; Elf *elf; GElf_Ehdr ehdr; @@ -658,6 +716,7 @@ int filename__read_debuglink(const char *filename, char *debuglink, close(fd); out: return err; +#endif } static int dso__swap_init(struct dso *dso, unsigned char eidata) -- 2.26.1
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