Re: [PATCH 06/26] perf tools: Add support to read build id from compressed elf

[Arnaldo Carvalho de Melo]

Em Sun, Sep 13, 2020 at 11:02:53PM +0200, Jiri Olsa escreveu:
> Adding support to decompress file before reading build id.
> 
> Adding filename__read_build_id and change its current
> versions to read_build_id.

Also a standalone, generally useful, prep patch, applyed.

- Arnaldo
 
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
>  tools/perf/util/symbol-elf.c | 37 ++++++++++++++++++++++++++++++++++--
>  1 file changed, 35 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
> index 94a156df22d5..6770572620f3 100644
> --- a/tools/perf/util/symbol-elf.c
> +++ b/tools/perf/util/symbol-elf.c
> @@ -534,7 +534,7 @@ static int elf_read_build_id(Elf *elf, void *bf, size_t size)
>  
>  #ifdef HAVE_LIBBFD_BUILDID_SUPPORT
>  
> -int filename__read_build_id(const char *filename, void *bf, size_t size)
> +static int read_build_id(const char *filename, void *bf, size_t size)
>  {
>  	int err = -1;
>  	bfd *abfd;
> @@ -562,7 +562,7 @@ int filename__read_build_id(const char *filename, void *bf, size_t size)
>  
>  #else // HAVE_LIBBFD_BUILDID_SUPPORT
>  
> -int filename__read_build_id(const char *filename, void *bf, size_t size)
> +static int read_build_id(const char *filename, void *bf, size_t size)
>  {
>  	int fd, err = -1;
>  	Elf *elf;
> @@ -591,6 +591,39 @@ int filename__read_build_id(const char *filename, void *bf, size_t size)
>  
>  #endif // HAVE_LIBBFD_BUILDID_SUPPORT
>  
> +int filename__read_build_id(const char *filename, void *bf, size_t size)
> +{
> +	struct kmod_path m = { .name = NULL, };
> +	char path[PATH_MAX];
> +	int err;
> +
> +	if (!filename)
> +		return -EFAULT;
> +
> +	err = kmod_path__parse(&m, filename);
> +	if (err)
> +		return -1;
> +
> +	if (m.comp) {
> +		int error = 0, fd;
> +
> +		fd = filename__decompress(filename, path, sizeof(path), m.comp, &error);
> +		if (fd < 0) {
> +			pr_debug("Failed to decompress (error %d) %s\n",
> +				 error, filename);
> +			return -1;
> +		}
> +		close(fd);
> +		filename = path;
> +	}
> +
> +	err = read_build_id(filename, bf, size);
> +
> +	if (m.comp)
> +		unlink(filename);
> +	return err;
> +}
> +
>  int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
>  {
>  	int fd, err = -1;
> -- 
> 2.26.2
> 

-- 

- Arnaldo