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SubjectRe: [PATCH v3 4/6] perf test: Decompress kernel module before objdump
On Wed, Jun 07, 2017 at 07:25:20PM -0300, Arnaldo Carvalho de Melo wrote:
> Em Thu, Jun 08, 2017 at 12:39:01AM +0900, Namhyung Kim escreveu:
> > If a kernel modules is compressed, it should be decompressed before
> > running objdump to parse binary data correctly. This fixes a failure of
> > object code reading test for me.
> >
> > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> > ---
> > tools/perf/tests/code-reading.c | 20 +++++++++++++++++++-
> > 1 file changed, 19 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c
> > index 1f14e7612cbb..94b7c7b02bde 100644
> > --- a/tools/perf/tests/code-reading.c
> > +++ b/tools/perf/tests/code-reading.c
> > @@ -229,6 +229,8 @@ static int read_object_code(u64 addr, size_t len, u8 cpumode,
> > unsigned char buf2[BUFSZ];
> > size_t ret_len;
> > u64 objdump_addr;
> > + const char *objdump_name;
> > + char decomp_name[KMOD_DECOMP_LEN];
> > int ret;
> >
> > pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr);
> > @@ -289,9 +291,25 @@ static int read_object_code(u64 addr, size_t len, u8 cpumode,
> > state->done[state->done_cnt++] = al.map->start;
> > }
> >
> > + objdump_name = al.map->dso->long_name;
> > + if (dso__needs_decompress(al.map->dso)) {
> > + if (dso__decompress_kmodule_path(al.map->dso, objdump_name,
> > + decomp_name,
> > + sizeof(decomp_name)) < 0) {
> > + pr_debug("decompression failed\n");
>
> This is a too vague message, to help with debugging I suggest printing
> more detauls such as the file being decompressed and perhaps the
> decomp_name as well.

Will add file name, but decomp_name might not be set on the failure path.

Thanks,
Namhyung


>
> > + return -1;
> > + }
> > +
> > + objdump_name = decomp_name;
> > + }
> > +
> > /* Read the object code using objdump */
> > objdump_addr = map__rip_2objdump(al.map, al.addr);
> > - ret = read_via_objdump(al.map->dso->long_name, objdump_addr, buf2, len);
> > + ret = read_via_objdump(objdump_name, objdump_addr, buf2, len);
> > +
> > + if (dso__needs_decompress(al.map->dso))
> > + unlink(objdump_name);
> > +
> > if (ret > 0) {
> > /*
> > * The kernel maps are inaccurate - assume objdump is right in
> > --
> > 2.13.0

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