perf symbols: Cleanup the code flow of dso__find_kallsyms

Cleanup the code flow of dso__find_kallsyms() to remove redundant
checking code and add some comment for readability.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160528151522.16098.43446.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Masami Hiramatsu 2016-05-29 00:15:28 +09:00 committed by Arnaldo Carvalho de Melo
parent 11870d714a
commit 4e4b6c0668

View file

@ -1674,21 +1674,8 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map)
sizeof(host_build_id)) == 0)
is_host = dso__build_id_equal(dso, host_build_id);
build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
scnprintf(path, sizeof(path), "%s/%s/%s", buildid_dir,
DSO__NAME_KCORE, sbuild_id);
/* Use /proc/kallsyms if possible */
/* Try a fast path for /proc/kallsyms if possible */
if (is_host) {
DIR *d;
/* If no cached kcore go with /proc/kallsyms */
d = opendir(path);
if (!d)
goto proc_kallsyms;
closedir(d);
/*
* Do not check the build-id cache, unless we know we cannot use
* /proc/kcore or module maps don't match to /proc/kallsyms.
@ -1699,18 +1686,24 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map)
if (filename__readable("/proc/kcore") &&
!validate_kcore_addresses("/proc/kallsyms", map))
goto proc_kallsyms;
/* Find kallsyms in build-id cache with kcore */
if (!find_matching_kcore(map, path, sizeof(path)))
return strdup(path);
goto proc_kallsyms;
}
build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
/* Find kallsyms in build-id cache with kcore */
scnprintf(path, sizeof(path), "%s/%s/%s",
buildid_dir, DSO__NAME_KCORE, sbuild_id);
if (!find_matching_kcore(map, path, sizeof(path)))
return strdup(path);
/* Use current /proc/kallsyms if possible */
if (is_host) {
proc_kallsyms:
return strdup("/proc/kallsyms");
}
/* Finally, find a cache of kallsyms */
scnprintf(path, sizeof(path), "%s/%s/%s",
buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
@ -1721,9 +1714,6 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map)
}
return strdup(path);
proc_kallsyms:
return strdup("/proc/kallsyms");
}
static int dso__load_kernel_sym(struct dso *dso, struct map *map,