Messages in this thread | | | From | Namhyung Kim <> | Date | Tue, 6 Jun 2017 10:42:59 +0900 | Subject | Re: [PATCH v2 3/3] perf test: Decompress kernel module before objdump |
| |
Hi Adrian,
On Mon, Jun 5, 2017 at 8:13 PM, Adrian Hunter <adrian.hunter@intel.com> wrote: > On 03/06/17 05:00, Namhyung Kim wrote: >> 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. > > Makes sense to me although I have a few small comments below.
Thanks!
> >> >> Signed-off-by: Namhyung Kim <namhyung@kernel.org> >> --- >> tools/perf/tests/code-reading.c | 26 +++++++++++++++++++++++++- >> 1 file changed, 25 insertions(+), 1 deletion(-) >> >> diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c >> index 1f14e7612cbb..fe6bd34d68b1 100644 >> --- a/tools/perf/tests/code-reading.c >> +++ b/tools/perf/tests/code-reading.c >> @@ -229,6 +229,7 @@ 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; >> int ret; >> >> pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr); >> @@ -289,9 +290,32 @@ 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)) { >> + char buf[32]; /* for "/tmp/perf-kmod-XXXXXX" */ > > We should be able to set the temporary file name buffer size without > reference to the format of the name i.e. #define it or use PATH_MAX
OK, will define KMOD_DECOMP_LEN then..
> >> + >> + if (dso__decompress_kmodule_path(al.map->dso, objdump_name, >> + buf, sizeof(buf)) < 0) { > > Do we care that it is kmodule i.e. why isn't this function called just > dso__decompress_path().
Well, I'm not sure loading a compressed DSO is making sense. Decompressing is needed for kernel modules which supports loading compressed modules.
> >> + pr_debug("decompression failed\n"); >> + return -1; >> + } >> + >> + objdump_name = strdup(buf); > > Why not just put the buf in the outer scope instead of using strdup().
Will change.
Thanks Namhyung
> >> + if (objdump_name == NULL) { >> + pr_debug("memory allocation failed\n"); >> + return -1; >> + } >> + } >> + >> /* 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 (objdump_name != al.map->dso->long_name) { >> + unlink(objdump_name); >> + free((void *)objdump_name); >> + } >> + >> if (ret > 0) { >> /* >> * The kernel maps are inaccurate - assume objdump is right in >> >
| |