Re: Re: [PATCH v2] perf probe: Find compilation directory path for lazy matching
From: Masami Hiramatsu
Date: Wed Mar 11 2015 - 21:43:04 EST
(2015/03/11 22:30), Arnaldo Carvalho de Melo wrote:
> Em Wed, Mar 04, 2015 at 09:34:38PM +0900, Masami Hiramatsu escreveu:
>> (2015/03/04 16:52), Naohiro Aota wrote:
>>> If we use lazy matching, it failed to open a souce file if perf command
>>> is invoked outside of compilation directory:
>>>
>>> $ perf probe -a '__schedule;clear_*'
>>> Failed to open kernel/sched/core.c: No such file or directory
>>> Error: Failed to add events. (-2)
>>>
>>> OTOH, other commands like "probe -L" can solve the souce directory by
>>> themselves. Let's make it possible for lazy matching too!
>>>
>>
>> Looks good to me :)
>>
>> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
>
> This doesn't make sense... se below:
>
>> Thank you!
>>
>>> diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
>>> index 46f009a..e6c0262 100644
>>> --- a/tools/perf/util/probe-finder.c
>>> +++ b/tools/perf/util/probe-finder.c
>>> @@ -849,11 +849,22 @@ static int probe_point_lazy_walker(const char *fname, int lineno,
>>> static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
>>> {
>>> int ret = 0;
>>> + char *fpath;
>>>
>>> if (intlist__empty(pf->lcache)) {
>>> + const char *comp_dir;
>>> +
>>> + comp_dir = cu_get_comp_dir(&pf->cu_die);
>>> + ret = get_real_path(pf->fname, comp_dir, &fpath);
>>> + if (ret < 0) {
>>> + pr_warning("Failed to find source file path.\n");
>>> + return ret;
>>> + }
>>> +
>>> /* Matching lazy line pattern */
>>> - ret = find_lazy_match_lines(pf->lcache, pf->fname,
>>> + ret = find_lazy_match_lines(pf->lcache, fpath,
>>> pf->pev->point.lazy_line);
>>> + free(fpath);
>>> if (ret <= 0)
>>> return ret;
>>> }
>>> @@ -1616,3 +1627,61 @@ found:
>>> return (ret < 0) ? ret : lf.found;
>>> }
>>>
>>> +/*
>>> + * Find a src file from a DWARF tag path. Prepend optional source path prefix
>>> + * and chop off leading directories that do not exist. Result is passed back as
>>> + * a newly allocated path on success.
>>> + * Return 0 if file was found and readable, -errno otherwise.
>>> + */
>>> +static int get_real_path(const char *raw_path, const char *comp_dir,
>>> + char **new_path)
>
> The function is marked "static"
>
>>> +{
>>> + const char *prefix = symbol_conf.source_prefix;
>>> +
>>> + if (!prefix) {
>>> + if (raw_path[0] != '/' && comp_dir)
>>> + /* If not an absolute path, try to use comp_dir */
>>> + prefix = comp_dir;
>>> + else {
>>> + if (access(raw_path, R_OK) == 0) {
>>> + *new_path = strdup(raw_path);
>>> + return *new_path ? 0 : -ENOMEM;
>>> + } else
>>> + return -errno;
>>> + }
>>> + }
>>> +
>>> + *new_path = malloc((strlen(prefix) + strlen(raw_path) + 2));
>>> + if (!*new_path)
>>> + return -ENOMEM;
>>> +
>>> + for (;;) {
>>> + sprintf(*new_path, "%s/%s", prefix, raw_path);
>>> +
>>> + if (access(*new_path, R_OK) == 0)
>>> + return 0;
>>> +
>>> + if (!symbol_conf.source_prefix) {
>>> + /* In case of searching comp_dir, don't retry */
>>> + zfree(new_path);
>>> + return -errno;
>>> + }
>>> +
>>> + switch (errno) {
>>> + case ENAMETOOLONG:
>>> + case ENOENT:
>>> + case EROFS:
>>> + case EFAULT:
>>> + raw_path = strchr(++raw_path, '/');
>>> + if (!raw_path) {
>>> + zfree(new_path);
>>> + return -ENOENT;
>>> + }
>>> + continue;
>>> +
>>> + default:
>>> + zfree(new_path);
>>> + return -errno;
>>> + }
>>> + }
>>> +}
>>> diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
>>> index 92590b2..5ef82dd 100644
>>> --- a/tools/perf/util/probe-finder.h
>>> +++ b/tools/perf/util/probe-finder.h
>>> @@ -55,6 +55,10 @@ extern int debuginfo__find_available_vars_at(struct debuginfo *dbg,
>>> struct variable_list **vls,
>>> int max_points, bool externs);
>>>
>>> +/* Find a src file from a DWARF tag path */
>>> +extern int get_real_path(const char *raw_path, const char *comp_dir,
>>> + char **new_path);
>>> +
>
> And then you mark it "extern"? Have you tried to compile this? I tried:
>
> CC /tmp/build/perf/tests/task-exit.o
> util/probe-finder.c:1636:12: error: static declaration of âget_real_pathâ follows non-static declaration
> static int get_real_path(const char *raw_path, const char *comp_dir,
> ^
> In file included from util/probe-finder.c:41:0:
> util/probe-finder.h:59:12: note: previous declaration of âget_real_pathâ was here
> extern int get_real_path(const char *raw_path, const char *comp_dir,
> ^
> util/probe-finder.c:1636:12: error: âget_real_pathâ defined but not used [-Werror=unused-function]
> static int get_real_path(const char *raw_path, const char *comp_dir,
> ^
> cc1: all warnings being treated as errors
> make[3]: *** [/tmp/build/perf/util/probe-finder.o] Error 1
> make[3]: *** Waiting for unfinished jobs....
> CC /tmp/build/perf/tests/sw-clock.o
>
> Also please refrain from using 'extern' in front of function prototypes, its just noise.1
Ooops! Sorry, I missed this ...
Naohiro, could you fix this?
Thanks,
>
> - Arnaldo
>
>>> struct probe_finder {
>>> struct perf_probe_event *pev; /* Target probe event */
>>>
>>>
>>
>>
>> --
>> Masami HIRAMATSU
>> Software Platform Research Dept. Linux Technology Research Center
>> Hitachi, Ltd., Yokohama Research Laboratory
>> E-mail: masami.hiramatsu.pt@xxxxxxxxxxx
>>
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--
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@xxxxxxxxxxx
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