Messages in this thread | | | Date | Mon, 16 Jan 2017 15:44:55 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH perf/core v2 4/4] perf-probe: Find probe events without target module |
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Em Wed, Jan 11, 2017 at 03:03:06PM +0900, Masami Hiramatsu escreveu: > Find probe events without -m "module" option. If perf-probe > failed to find given function in kernel image, it tries to > find same symbol and module in kallsyms, and retry search > in the found module. E.g. > > # perf probe -D i915_capabilities > p:probe/i915_capabilities i915:i915_capabilities+0 > > Note: without -m option, perf probe can not find inlined > function since there is no symbol information in kallsyms.
As this is a new feature, I'll postpone merging it till we get perf/urgent, with the first three patches in this series, merged into perf/core, ok?
- Arnaldo
> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> > Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com> > --- > Changes in v2: > - Fix to remove unneeded zero-return. > - Remove unneeded debug message. > --- > tools/perf/util/probe-event.c | 69 ++++++++++++++++++++++++++++++----------- > 1 file changed, 51 insertions(+), 18 deletions(-) > > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c > index 6a6f44d..715f330 100644 > --- a/tools/perf/util/probe-event.c > +++ b/tools/perf/util/probe-event.c > @@ -858,11 +858,7 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev, > > debuginfo__delete(dinfo); > > - if (ntevs == 0) { /* No error but failed to find probe point. */ > - pr_warning("Probe point '%s' not found.\n", > - synthesize_perf_probe_point(&pev->point)); > - return -ENOENT; > - } else if (ntevs < 0) { > + if (ntevs < 0) { > /* Error path : ntevs < 0 */ > pr_debug("An error occurred in debuginfo analysis (%d).\n", ntevs); > if (ntevs == -EBADF) > @@ -2829,9 +2825,7 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, > */ > num_matched_functions = find_probe_functions(map, pp->function, syms); > if (num_matched_functions == 0) { > - pr_err("Failed to find symbol %s in %s\n", pp->function, > - pev->target ? : "kernel"); > - ret = -ENOENT; > + ret = 0; > goto out; > } else if (num_matched_functions > probe_conf.max_probes) { > pr_err("Too many functions matched in %s\n", > @@ -3233,6 +3227,42 @@ static int find_probe_trace_events_from_cache(struct perf_probe_event *pev, > return ret; > } > > +static int __convert_to_probe_trace_events(struct perf_probe_event *pev, > + struct probe_trace_event **tevs) > +{ > + int ret; > + > + /* At first, we need to lookup cache entry */ > + ret = find_probe_trace_events_from_cache(pev, tevs); > + if (ret > 0 || pev->sdt) /* SDT can be found only in the cache */ > + return ret == 0 ? -ENOENT : ret; /* Found in probe cache */ > + > + /* Convert perf_probe_event with debuginfo */ > + ret = try_to_find_probe_trace_events(pev, tevs); > + if (ret != 0) > + return ret; /* Found in debuginfo or got an error */ > + > + return find_probe_trace_events_from_map(pev, tevs); > +} > + > +static char *find_module_from_kallsyms(const char *symbol_name) > +{ > + struct machine *machine = machine__new_kallsyms(); > + struct symbol *sym; > + struct map *map; > + char *module; > + > + sym = machine__find_kernel_function_by_name(machine, symbol_name, &map); > + if (!sym || map->dso->short_name[0] != '[') > + return NULL; > + pr_debug("Found %s in %s\n", sym->name, map->dso->short_name); > + module = strdup(map->dso->short_name + 1); > + if (module) > + module[strlen(module) - 1] = '\0'; > + > + return module; > +} > + > static int convert_to_probe_trace_events(struct perf_probe_event *pev, > struct probe_trace_event **tevs) > { > @@ -3255,17 +3285,20 @@ static int convert_to_probe_trace_events(struct perf_probe_event *pev, > if (ret > 0) > return ret; > > - /* At first, we need to lookup cache entry */ > - ret = find_probe_trace_events_from_cache(pev, tevs); > - if (ret > 0 || pev->sdt) /* SDT can be found only in the cache */ > - return ret == 0 ? -ENOENT : ret; /* Found in probe cache */ > - > - /* Convert perf_probe_event with debuginfo */ > - ret = try_to_find_probe_trace_events(pev, tevs); > - if (ret != 0) > - return ret; /* Found in debuginfo or got an error */ > + ret = __convert_to_probe_trace_events(pev, tevs); > + /* Not found. will retry to check kmodule if possible */ > + if (ret == 0 && !pev->uprobes && !pev->target) { > + pev->target = find_module_from_kallsyms(pev->point.function); > + if (pev->target) > + ret = __convert_to_probe_trace_events(pev, tevs); > + } > > - return find_probe_trace_events_from_map(pev, tevs); > + if (ret == 0) { > + pr_warning("Probe point '%s' not found.\n", > + synthesize_perf_probe_point(&pev->point)); > + ret = -ENOENT; > + } > + return ret; > } > > int convert_perf_probe_events(struct perf_probe_event *pevs, int npevs)
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