Re: [PATCH 04/26] perf tools: Add filename__decompress function

Arnaldo Carvalho de Melo
2020-09-14T15:36:59Z

Em Sun, Sep 13, 2020 at 11:02:51PM +0200, Jiri Olsa escreveu:
> Factor filename__decompress from decompress_kmodule function.
> It can decompress files with compressions supported in perf -
> xz and gz, the support needs to be compiled in.
>
> It will to be used in following changes to get build id out of
> compressed elf objects.

This is prep work, can be applied now, done.

- Arnaldo

> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
> tools/perf/util/dso.c | 31 +++++++++++++++++++------------
> tools/perf/util/dso.h | 2 ++
> 2 files changed, 21 insertions(+), 12 deletions(-)
>
> diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
> index 5a3b4755f0b3..0faa96ca7a04 100644
> --- a/tools/perf/util/dso.c
> +++ b/tools/perf/util/dso.c
> @@ -279,18 +279,12 @@ bool dso__needs_decompress(struct dso *dso)
> dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
> }
>
> -static int decompress_kmodule(struct dso *dso, const char *name,
> - char *pathname, size_t len)
> +int filename__decompress(const char *name, char *pathname,
> + size_t len, int comp, int *err)
> {
> char tmpbuf[] = KMOD_DECOMP_NAME;
> int fd = -1;
>
> - if (!dso__needs_decompress(dso))
> - return -1;
> -
> - if (dso->comp == COMP_ID__NONE)
> - return -1;
> -
> /*
> * We have proper compression id for DSO and yet the file
> * behind the 'name' can still be plain uncompressed object.
> @@ -304,17 +298,17 @@ static int decompress_kmodule(struct dso *dso, const char *name,
> * To keep this transparent, we detect this and return the file
> * descriptor to the uncompressed file.
> */
> - if (!compressions[dso->comp].is_compressed(name))
> + if (!compressions[comp].is_compressed(name))
> return open(name, O_RDONLY);
>
> fd = mkstemp(tmpbuf);
> if (fd < 0) {
> - dso->load_errno = errno;
> + *err = errno;
> return -1;
> }
>
> - if (compressions[dso->comp].decompress(name, fd)) {
> - dso->load_errno = DSO_LOAD_ERRNO__DECOMPRESSION_FAILURE;
> + if (compressions[comp].decompress(name, fd)) {
> + *err = DSO_LOAD_ERRNO__DECOMPRESSION_FAILURE;
> close(fd);
> fd = -1;
> }
> @@ -328,6 +322,19 @@ static int decompress_kmodule(struct dso *dso, const char *name,
> return fd;
> }
>
> +static int decompress_kmodule(struct dso *dso, const char *name,
> + char *pathname, size_t len)
> +{
> + if (!dso__needs_decompress(dso))
> + return -1;
> +
> + if (dso->comp == COMP_ID__NONE)
> + return -1;
> +
> + return filename__decompress(name, pathname, len, dso->comp,
> + &dso->load_errno);
> +}
> +
> int dso__decompress_kmodule_fd(struct dso *dso, const char *name)
> {
> return decompress_kmodule(dso, name, NULL, 0);
> diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
> index 8ad17f395a19..f1efd2e11547 100644
> --- a/tools/perf/util/dso.h
> +++ b/tools/perf/util/dso.h
> @@ -274,6 +274,8 @@ bool dso__needs_decompress(struct dso *dso);
> int dso__decompress_kmodule_fd(struct dso *dso, const char *name);
> int dso__decompress_kmodule_path(struct dso *dso, const char *name,
> char *pathname, size_t len);
> +int filename__decompress(const char *name, char *pathname,
> + size_t len, int comp, int *err);
>
> #define KMOD_DECOMP_NAME "/tmp/perf-kmod-XXXXXX"
> #define KMOD_DECOMP_LEN sizeof(KMOD_DECOMP_NAME)
> --
> 2.26.2
>

--

- Arnaldo