Em Mon, Sep 07, 2015 at 10:38:06AM +0200, Jiri Olsa escreveu: > Propagate error info from tp_format via ERR_PTR to get > it all the way down to the parse-event.c tracepoint adding > routines. Following functions now return pointer with > encoded error: > - tp_format > - trace_event__tp_format > - perf_evsel__newtp_idx > - perf_evsel__newtp > > This affects several other places in perf, that cannot use > pointer check anymore, but must utilize the err.h interface, > when getting error information from above functions list.
Right, so this is tricky and we must be careful, see below... > Link: http://lkml.kernel.org/n/tip-bzdckgv1zfp2y8up9l7oj...@git.kernel.org > Signed-off-by: Jiri Olsa <jo...@kernel.org> > --- > tools/perf/builtin-trace.c | 19 +++++++++++-------- > tools/perf/tests/evsel-tp-sched.c | 10 ++++++++-- > tools/perf/tests/openat-syscall-all-cpus.c | 3 ++- > tools/perf/tests/openat-syscall-tp-fields.c | 3 ++- > tools/perf/tests/openat-syscall.c | 3 ++- > tools/perf/util/evlist.c | 3 ++- > tools/perf/util/evsel.c | 11 +++++++++-- > tools/perf/util/evsel.h | 3 +++ > tools/perf/util/parse-events.c | 6 +++--- > tools/perf/util/trace-event.c | 13 +++++++++++-- > 10 files changed, 53 insertions(+), 21 deletions(-) > > diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c > index 215653274102..93b80f12f35e 100644 > --- a/tools/perf/builtin-trace.c > +++ b/tools/perf/builtin-trace.c > @@ -38,6 +38,7 @@ > #include <stdlib.h> > #include <sys/mman.h> > #include <linux/futex.h> > +#include <linux/err.h> > > /* For older distros: */ > #ifndef MAP_STACK > @@ -245,13 +246,14 @@ static struct perf_evsel > *perf_evsel__syscall_newtp(const char *direction, void > struct perf_evsel *evsel = perf_evsel__newtp("raw_syscalls", direction); > > /* older kernel (e.g., RHEL6) use syscalls:{enter,exit} */ > - if (evsel == NULL) > + if (IS_ERR(evsel)) > evsel = perf_evsel__newtp("syscalls", direction); > > - if (evsel) { > - if (perf_evsel__init_syscall_tp(evsel, handler)) > - goto out_delete; > - } > + if (IS_ERR(evsel)) > + return NULL; > + > + if (perf_evsel__init_syscall_tp(evsel, handler)) > + goto out_delete; This kind of stuff is ok, as evsel is a local variable and you kept the interface for perf_evsel__syscall_newtp(), i.e. it returns NULL if a new evsel can't be instantiated. Ok, but that is a different interface than the one used by perf_evsel__newtp(), that also instantiates a new evsel. So when one thinks about "foo__new()" we now need to check which one of the two interfaces it uses, if err.h or if the old NULL based failure reporting one. Double tricky if it is foo__new() and foo__new_variant(), as perf_evsel__syscall_newtp() and perf_evsel__newtp(), i.e. both will return a "struct perf_evsel" instance, but one using err.h, the other use NULL. Ok, you marked the ones using a comment, wonder if we couldn't use 'sparse' somehow here, is it used to check IS_ERR() usage in the kernel? Ah, but what about this in trace__event_handler() in builtin-trace.c? if (evsel->tp_format) { event_format__fprintf(evsel->tp_format, sample->cpu, sample->raw_data, sample->raw_size, trace->output); } Don't we have to use IS_ERR() here? Ok, no, because if setting up evsel->tp_format fails, then that evsel will be destroyed and perf_evsel__newtp() will return ERR_PTR(), so it is ok not no use ERR_PTR(evsel->tp_format) because it will only be != NULL when it was successfully set up. But then, in perf_evsel__newtp_idx if zalloc() fails we will not return ERR_PTR(), but instead NULL, a-ha, this one seems to be a real bug, no? /* * Returns pointer with encoded error via <linux/err.h> interface. */ struct perf_evsel *perf_evsel__newtp_idx(const char *sys, const char *name, int idx) { struct perf_evsel *evsel = zalloc(perf_evsel__object.size); int err = -ENOMEM; if (evsel != NULL) { struct perf_event_attr attr = { .type = PERF_TYPE_TRACEPOINT, .sample_type = (PERF_SAMPLE_RAW | PERF_SAMPLE_TIME | PERF_SAMPLE_CPU | PERF_SAMPLE_PERIOD), }; if (asprintf(&evsel->name, "%s:%s", sys, name) < 0) goto out_free; evsel->tp_format = trace_event__tp_format(sys, name); if (IS_ERR(evsel->tp_format)) { err = PTR_ERR(evsel->tp_format); goto out_free; } event_attr_init(&attr); attr.config = evsel->tp_format->id; attr.sample_period = 1; perf_evsel__init(evsel, &attr, idx); } return evsel; out_free: zfree(&evsel->name); free(evsel); return ERR_PTR(err); } > > return evsel; > > @@ -1705,12 +1707,12 @@ static int trace__read_syscall_info(struct trace > *trace, int id) > snprintf(tp_name, sizeof(tp_name), "sys_enter_%s", sc->name); > sc->tp_format = trace_event__tp_format("syscalls", tp_name); > > - if (sc->tp_format == NULL && sc->fmt && sc->fmt->alias) { > + if (IS_ERR(sc->tp_format) && sc->fmt && sc->fmt->alias) { > snprintf(tp_name, sizeof(tp_name), "sys_enter_%s", > sc->fmt->alias); > sc->tp_format = trace_event__tp_format("syscalls", tp_name); > } > > - if (sc->tp_format == NULL) > + if (IS_ERR(sc->tp_format)) > return -1; > > sc->args = sc->tp_format->format.fields; > @@ -2390,7 +2392,8 @@ static size_t trace__fprintf_thread_summary(struct > trace *trace, FILE *fp); > static bool perf_evlist__add_vfs_getname(struct perf_evlist *evlist) > { > struct perf_evsel *evsel = perf_evsel__newtp("probe", "vfs_getname"); > - if (evsel == NULL) > + > + if (IS_ERR(evsel)) > return false; > > if (perf_evsel__field(evsel, "pathname") == NULL) { > diff --git a/tools/perf/tests/evsel-tp-sched.c > b/tools/perf/tests/evsel-tp-sched.c > index 52162425c969..790e413d9a1f 100644 > --- a/tools/perf/tests/evsel-tp-sched.c > +++ b/tools/perf/tests/evsel-tp-sched.c > @@ -1,3 +1,4 @@ > +#include <linux/err.h> > #include <traceevent/event-parse.h> > #include "evsel.h" > #include "tests.h" > @@ -36,8 +37,8 @@ int test__perf_evsel__tp_sched_test(void) > struct perf_evsel *evsel = perf_evsel__newtp("sched", "sched_switch"); > int ret = 0; > > - if (evsel == NULL) { > - pr_debug("perf_evsel__new\n"); > + if (IS_ERR(evsel)) { > + pr_debug("perf_evsel__newtp failed with %ld\n", PTR_ERR(evsel)); > return -1; > } > > @@ -66,6 +67,11 @@ int test__perf_evsel__tp_sched_test(void) > > evsel = perf_evsel__newtp("sched", "sched_wakeup"); > > + if (IS_ERR(evsel)) { > + pr_debug("perf_evsel__newtp failed with %ld\n", PTR_ERR(evsel)); > + return -1; > + } > + > if (perf_evsel__test_field(evsel, "comm", 16, true)) > ret = -1; > > diff --git a/tools/perf/tests/openat-syscall-all-cpus.c > b/tools/perf/tests/openat-syscall-all-cpus.c > index 495d8126b722..9e104a2e973d 100644 > --- a/tools/perf/tests/openat-syscall-all-cpus.c > +++ b/tools/perf/tests/openat-syscall-all-cpus.c > @@ -1,4 +1,5 @@ > #include <api/fs/fs.h> > +#include <linux/err.h> > #include "evsel.h" > #include "tests.h" > #include "thread_map.h" > @@ -31,7 +32,7 @@ int test__openat_syscall_event_on_all_cpus(void) > CPU_ZERO(&cpu_set); > > evsel = perf_evsel__newtp("syscalls", "sys_enter_openat"); > - if (evsel == NULL) { > + if (IS_ERR(evsel)) { > tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), > "syscalls", "sys_enter_openat"); > pr_err("%s\n", errbuf); > goto out_thread_map_delete; > diff --git a/tools/perf/tests/openat-syscall-tp-fields.c > b/tools/perf/tests/openat-syscall-tp-fields.c > index 01a19626c846..473d3869727e 100644 > --- a/tools/perf/tests/openat-syscall-tp-fields.c > +++ b/tools/perf/tests/openat-syscall-tp-fields.c > @@ -1,3 +1,4 @@ > +#include <linux/err.h> > #include "perf.h" > #include "evlist.h" > #include "evsel.h" > @@ -30,7 +31,7 @@ int test__syscall_openat_tp_fields(void) > } > > evsel = perf_evsel__newtp("syscalls", "sys_enter_openat"); > - if (evsel == NULL) { > + if (IS_ERR(evsel)) { > pr_debug("%s: perf_evsel__newtp\n", __func__); > goto out_delete_evlist; > } > diff --git a/tools/perf/tests/openat-syscall.c > b/tools/perf/tests/openat-syscall.c > index 08ac9d94a050..7b1db8306098 100644 > --- a/tools/perf/tests/openat-syscall.c > +++ b/tools/perf/tests/openat-syscall.c > @@ -1,4 +1,5 @@ > #include <api/fs/tracing_path.h> > +#include <linux/err.h> > #include "thread_map.h" > #include "evsel.h" > #include "debug.h" > @@ -19,7 +20,7 @@ int test__openat_syscall_event(void) > } > > evsel = perf_evsel__newtp("syscalls", "sys_enter_openat"); > - if (evsel == NULL) { > + if (IS_ERR(evsel)) { > tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), > "syscalls", "sys_enter_openat"); > pr_err("%s\n", errbuf); > goto out_thread_map_delete; > diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c > index d51a5200c8af..3cb2bf9bd4bd 100644 > --- a/tools/perf/util/evlist.c > +++ b/tools/perf/util/evlist.c > @@ -25,6 +25,7 @@ > #include <linux/bitops.h> > #include <linux/hash.h> > #include <linux/log2.h> > +#include <linux/err.h> > > static void perf_evlist__mmap_put(struct perf_evlist *evlist, int idx); > static void __perf_evlist__munmap(struct perf_evlist *evlist, int idx); > @@ -265,7 +266,7 @@ int perf_evlist__add_newtp(struct perf_evlist *evlist, > { > struct perf_evsel *evsel = perf_evsel__newtp(sys, name); > > - if (evsel == NULL) > + if (IS_ERR(evsel)) > return -1; > > evsel->handler = handler; > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c > index 771ade4d5966..08c20ee4e27d 100644 > --- a/tools/perf/util/evsel.c > +++ b/tools/perf/util/evsel.c > @@ -13,6 +13,7 @@ > #include <traceevent/event-parse.h> > #include <linux/hw_breakpoint.h> > #include <linux/perf_event.h> > +#include <linux/err.h> > #include <sys/resource.h> > #include "asm/bug.h" > #include "callchain.h" > @@ -225,9 +226,13 @@ struct perf_evsel *perf_evsel__new_idx(struct > perf_event_attr *attr, int idx) > return evsel; > } > > +/* > + * Returns pointer with encoded error via <linux/err.h> interface. > + */ > struct perf_evsel *perf_evsel__newtp_idx(const char *sys, const char *name, > int idx) > { > struct perf_evsel *evsel = zalloc(perf_evsel__object.size); > + int err = -ENOMEM; > > if (evsel != NULL) { > struct perf_event_attr attr = { > @@ -240,8 +245,10 @@ struct perf_evsel *perf_evsel__newtp_idx(const char > *sys, const char *name, int > goto out_free; > > evsel->tp_format = trace_event__tp_format(sys, name); > - if (evsel->tp_format == NULL) > + if (IS_ERR(evsel->tp_format)) { > + err = PTR_ERR(evsel->tp_format); > goto out_free; > + } > > event_attr_init(&attr); > attr.config = evsel->tp_format->id; > @@ -254,7 +261,7 @@ struct perf_evsel *perf_evsel__newtp_idx(const char *sys, > const char *name, int > out_free: > zfree(&evsel->name); > free(evsel); > - return NULL; > + return ERR_PTR(err); > } > > const char *perf_evsel__hw_names[PERF_COUNT_HW_MAX] = { > diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h > index 298e6bbca200..b6e8ff876f17 100644 > --- a/tools/perf/util/evsel.h > +++ b/tools/perf/util/evsel.h > @@ -161,6 +161,9 @@ static inline struct perf_evsel *perf_evsel__new(struct > perf_event_attr *attr) > > struct perf_evsel *perf_evsel__newtp_idx(const char *sys, const char *name, > int idx); > > +/* > + * Returns pointer with encoded error via <linux/err.h> interface. > + */ > static inline struct perf_evsel *perf_evsel__newtp(const char *sys, const > char *name) > { > return perf_evsel__newtp_idx(sys, name, 0); > diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c > index 1b284b8ad243..c47831c47220 100644 > --- a/tools/perf/util/parse-events.c > +++ b/tools/perf/util/parse-events.c > @@ -1,4 +1,5 @@ > #include <linux/hw_breakpoint.h> > +#include <linux/err.h> > #include "util.h" > #include "../perf.h" > #include "evlist.h" > @@ -393,11 +394,10 @@ static int add_tracepoint(struct list_head *list, int > *idx, > struct perf_evsel *evsel; > > evsel = perf_evsel__newtp_idx(sys_name, evt_name, (*idx)++); > - if (!evsel) > - return -ENOMEM; > + if (IS_ERR(evsel)) > + return PTR_ERR(evsel); > > list_add_tail(&evsel->node, list); > - > return 0; > } > > diff --git a/tools/perf/util/trace-event.c b/tools/perf/util/trace-event.c > index 2f4996ab313d..8e3a60e3e15f 100644 > --- a/tools/perf/util/trace-event.c > +++ b/tools/perf/util/trace-event.c > @@ -7,6 +7,7 @@ > #include <sys/stat.h> > #include <fcntl.h> > #include <linux/kernel.h> > +#include <linux/err.h> > #include <traceevent/event-parse.h> > #include <api/fs/tracing_path.h> > #include "trace-event.h" > @@ -66,6 +67,9 @@ void trace_event__cleanup(struct trace_event *t) > pevent_free(t->pevent); > } > > +/* > + * Returns pointer with encoded error via <linux/err.h> interface. > + */ > static struct event_format* > tp_format(const char *sys, const char *name) > { > @@ -74,12 +78,14 @@ tp_format(const char *sys, const char *name) > char path[PATH_MAX]; > size_t size; > char *data; > + int err; > > scnprintf(path, PATH_MAX, "%s/%s/%s/format", > tracing_events_path, sys, name); > > - if (filename__read_str(path, &data, &size)) > - return NULL; > + err = filename__read_str(path, &data, &size); > + if (err) > + return ERR_PTR(err); > > pevent_parse_format(pevent, &event, data, size, sys); > > @@ -87,6 +93,9 @@ tp_format(const char *sys, const char *name) > return event; > } > > +/* > + * Returns pointer with encoded error via <linux/err.h> interface. > + */ > struct event_format* > trace_event__tp_format(const char *sys, const char *name) > { > -- > 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
