diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index bc2eb7cda2d1..a9774628c6f6 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -265,6 +265,65 @@ static bool kprobe_warn_out_range(const char *symbol, unsigned long address) return true; } +/* + * NOTE: + * '.gnu.linkonce.this_module' section of kernel module elf directly + * maps to 'struct module' from linux/module.h. This section contains + * actual module name which will be used by kernel after loading it. + * But, we cannot use 'struct module' here since linux/module.h is not + * exposed to user-space. Offset of 'name' has remained same from long + * time, so hardcoding it here. + */ +#ifdef __LP64__ +#define MOD_NAME_OFFSET 24 +#else +#define MOD_NAME_OFFSET 12 +#endif + +/* + * @module can be module name of module file path. In case of path, + * inspect elf and find out what is actual module name. + * Caller has to free mod_name after using it. + */ +static char *find_module_name(const char *module) +{ + int fd; + Elf *elf; + GElf_Ehdr ehdr; + GElf_Shdr shdr; + Elf_Data *data; + Elf_Scn *sec; + char *mod_name = NULL; + + fd = open(module, O_RDONLY); + if (fd < 0) + return NULL; + + elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); + if (elf == NULL) + goto elf_err; + + if (gelf_getehdr(elf, &ehdr) == NULL) + goto ret_err; + + sec = elf_section_by_name(elf, &ehdr, &shdr, + ".gnu.linkonce.this_module", NULL); + if (!sec) + goto ret_err; + + data = elf_getdata(sec, NULL); + if (!data || !data->d_buf) + goto ret_err; + + mod_name = strdup((char *)data->d_buf + MOD_NAME_OFFSET); + +ret_err: + elf_end(elf); +elf_err: + close(fd); + return mod_name; +} + #ifdef HAVE_DWARF_SUPPORT static int kernel_get_module_dso(const char *module, struct dso **pdso) @@ -2512,6 +2571,7 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, struct probe_trace_point *tp; int num_matched_functions; int ret, i, j, skipped = 0; + char *mod_name; map = get_target_map(pev->target, pev->uprobes); if (!map) { @@ -2596,9 +2656,19 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, tp->realname = strdup_or_goto(sym->name, nomem_out); tp->retprobe = pp->retprobe; - if (pev->target) - tev->point.module = strdup_or_goto(pev->target, - nomem_out); + if (pev->target) { + if (pev->uprobes) { + tev->point.module = strdup_or_goto(pev->target, + nomem_out); + } else { + mod_name = find_module_name(pev->target); + tev->point.module = + strdup(mod_name ? mod_name : pev->target); + free(mod_name); + if (!tev->point.module) + goto nomem_out; + } + } tev->uprobes = pev->uprobes; tev->nargs = pev->nargs; if (tev->nargs) {