Messages in this thread Patch in this message | | | Date | Wed, 26 Feb 2020 16:11:32 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH 2/2] perf: probe-file: Check return value of strlist__add |
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On Wed, 26 Feb 2020 10:49:19 +0800 He Zhe <zhe.he@windriver.com> wrote:
> > > On 2/26/20 6:49 AM, Masami Hiramatsu wrote: > > On Tue, 25 Feb 2020 22:41:43 +0800 > > <zhe.he@windriver.com> wrote: > > > >> From: He Zhe <zhe.he@windriver.com> > >> > >> strlist__add may fail with -ENOMEM or -EEXIST. Check it and give debugging > >> hint when necessary. > >> > >> Signed-off-by: He Zhe <zhe.he@windriver.com> > >> --- > >> tools/perf/builtin-probe.c | 30 ++++++++++++++++-------------- > >> tools/perf/util/probe-file.c | 26 +++++++++++++++++++++----- > >> 2 files changed, 37 insertions(+), 19 deletions(-) > >> > >> diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c > >> index 26bc5923e6b5..8b4511c70fed 100644 > >> --- a/tools/perf/builtin-probe.c > >> +++ b/tools/perf/builtin-probe.c > >> @@ -442,24 +442,26 @@ static int perf_del_probe_events(struct strfilter *filter) > >> } > >> > >> ret = probe_file__get_events(kfd, filter, klist); > >> - if (ret == 0) { > >> - strlist__for_each_entry(ent, klist) > >> - pr_info("Removed event: %s\n", ent->s); > >> + if (ret < 0) > >> + goto out; > > No, this is ignored by design. > > Since probe_file__get_events() returns -ENOENT when no event is matched, > > this should be just ignored, and goto uprobe event matching. > > Thanks for pointing it out. However when strlist__add in probe_file__get_events > returns a -ENOMEM and we ignore that, though it happens not very likely, we > would miss some entries. So I add checks here and in probe_file__get_events to > give a heads-up in advance.
If you are aware of -ENOMEM ( I guess in such case you'll see OOM killer sooner or later ), please just catch it. I mean
if (ret == -ENOMEM) goto out;
will be good.
Thank you,
> > And the same reason is for the checks below for probe_cache__load, > probe_cache__add_entry and probe_cache__scan_sdt. > > > Regards, > Zhe > > > > >> > >> - ret = probe_file__del_strlist(kfd, klist); > >> - if (ret < 0) > >> - goto error; > >> - } > >> + strlist__for_each_entry(ent, klist) > >> + pr_info("Removed event: %s\n", ent->s); > >> + > >> + ret = probe_file__del_strlist(kfd, klist); > >> + if (ret < 0) > >> + goto error; > >> > >> ret2 = probe_file__get_events(ufd, filter, ulist); > >> - if (ret2 == 0) { > >> - strlist__for_each_entry(ent, ulist) > >> - pr_info("Removed event: %s\n", ent->s); > >> + if (ret2 < 0) > >> + goto out; > > Ditto. > > > > Thank you, > > > >> > >> - ret2 = probe_file__del_strlist(ufd, ulist); > >> - if (ret2 < 0) > >> - goto error; > >> - } > >> + strlist__for_each_entry(ent, ulist) > >> + pr_info("Removed event: %s\n", ent->s); > >> + > >> + ret2 = probe_file__del_strlist(ufd, ulist); > >> + if (ret2 < 0) > >> + goto error; > >> > >> if (ret == -ENOENT && ret2 == -ENOENT) > >> pr_warning("\"%s\" does not hit any event.\n", str); > >> diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c > >> index cf44c05f89c1..00f086cba88f 100644 > >> --- a/tools/perf/util/probe-file.c > >> +++ b/tools/perf/util/probe-file.c > >> @@ -307,10 +307,14 @@ int probe_file__get_events(int fd, struct strfilter *filter, > >> p = strchr(ent->s, ':'); > >> if ((p && strfilter__compare(filter, p + 1)) || > >> strfilter__compare(filter, ent->s)) { > >> - strlist__add(plist, ent->s); > >> - ret = 0; > >> + ret = strlist__add(plist, ent->s); > >> + if (ret < 0) { > >> + pr_debug("strlist__add failed (%d)\n", ret); > >> + goto out; > >> + } > >> } > >> } > >> +out: > >> strlist__delete(namelist); > >> > >> return ret; > >> @@ -517,7 +521,11 @@ static int probe_cache__load(struct probe_cache *pcache) > >> ret = -EINVAL; > >> goto out; > >> } > >> - strlist__add(entry->tevlist, buf); > >> + ret = strlist__add(entry->tevlist, buf); > >> + if (ret < 0) { > >> + pr_debug("strlist__add failed (%d)\n", ret); > >> + goto out; > >> + } > >> } > >> } > >> out: > >> @@ -678,7 +686,12 @@ int probe_cache__add_entry(struct probe_cache *pcache, > >> command = synthesize_probe_trace_command(&tevs[i]); > >> if (!command) > >> goto out_err; > >> - strlist__add(entry->tevlist, command); > >> + ret = strlist__add(entry->tevlist, command); > >> + if (ret < 0) { > >> + pr_debug("strlist__add failed (%d)\n", ret); > >> + goto out_err; > >> + } > >> + > >> free(command); > >> } > >> list_add_tail(&entry->node, &pcache->entries); > >> @@ -859,7 +872,10 @@ int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname) > >> break; > >> } > >> > >> - strlist__add(entry->tevlist, buf); > >> + ret = strlist__add(entry->tevlist, buf); > >> + if (ret < 0) > >> + pr_debug("strlist__add failed (%d)\n", ret); > >> + > >> free(buf); > >> entry = NULL; > >> } > >> -- > >> 2.24.1 > >> > > >
-- Masami Hiramatsu <mhiramat@kernel.org>
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