On Fri, Aug 21, 2020 at 06:52:36PM +0200, Remi Bernon wrote:
> 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: Remi Bernon <rber...@codeweavers.com>
> Cc: Alexander Shishkin <alexander.shish...@linux.intel.com>
> Cc: Arnaldo Carvalho de Melo <a...@kernel.org>
> Cc: Ingo Molnar <mi...@redhat.com>
> Cc: Jiri Olsa <jo...@redhat.com>
> Cc: Mark Rutland <mark.rutl...@arm.com>
> Cc: Namhyung Kim <namhy...@kernel.org>
> Cc: Peter Zijlstra <pet...@infradead.org>
> Cc: Jacek Caban <ja...@codeweavers.com>
> ---
>
> v3: Rebase and small changes to PATCH 2/3 and and PATCH 3/3.
all 3 patches look ok to me especially since I found out the new
code for loading symbols is for non ELF objects only ;-)
it'd be great if somebody with libbfd skills could review this,
but for me it looks ok.. for patchset:
Acked-by: Jiri Olsa <jo...@redhat.com>
thanks,
jirka
>
> tools/perf/util/symbol-elf.c | 80 ++++++++++++++++++++++++++++++++++--
> 1 file changed, 77 insertions(+), 3 deletions(-)
>
> diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
> index 8cc4b0059fb0..f7432c4a4154 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
>
> @@ -530,6 +532,36 @@ static int elf_read_build_id(Elf *elf, void *bf, size_t
> size)
> return err;
> }
>
> +#ifdef HAVE_LIBBFD_SUPPORT
> +
> +int filename__read_build_id(const char *filename, void *bf, size_t size)
> +{
> + 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 = abfd->build_id->size;
> +
> +out_close:
> + bfd_close(abfd);
> + return err;
> +}
> +
> +#else
> +
> int filename__read_build_id(const char *filename, void *bf, size_t size)
> {
> int fd, err = -1;
> @@ -557,6 +589,8 @@ int filename__read_build_id(const char *filename, void
> *bf, size_t size)
> return err;
> }
>
> +#endif
> +
> int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
> {
> int fd, err = -1;
> @@ -608,6 +642,44 @@ int sysfs__read_build_id(const char *filename, void
> *build_id, size_t size)
> return err;
> }
>
> +#ifdef HAVE_LIBBFD_SUPPORT
> +
> +int filename__read_debuglink(const char *filename, char *debuglink,
> + size_t size)
> +{
> + 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 filename__read_debuglink(const char *filename, char *debuglink,
> size_t size)
> {
> @@ -660,6 +732,8 @@ int filename__read_debuglink(const char *filename, char
> *debuglink,
> return err;
> }
>
> +#endif
> +
> static int dso__swap_init(struct dso *dso, unsigned char eidata)
> {
> static unsigned int const endian = 1;
> --
> 2.28.0
>
