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Diffstat (limited to 'tools/perf/util/probe-event.c')
-rw-r--r--tools/perf/util/probe-event.c166
1 files changed, 114 insertions, 52 deletions
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index d281ae2b54e8..6a6f44dd594b 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -163,7 +163,7 @@ static struct map *kernel_get_module_map(const char *module)
/* A file path -- this is an offline module */
if (module && strchr(module, '/'))
- return machine__findnew_module_map(host_machine, 0, module);
+ return dso__new_map(module);
if (!module)
module = "kernel";
@@ -173,6 +173,7 @@ static struct map *kernel_get_module_map(const char *module)
if (strncmp(pos->dso->short_name + 1, module,
pos->dso->short_name_len - 2) == 0 &&
module[pos->dso->short_name_len - 2] == '\0') {
+ map__get(pos);
return pos;
}
}
@@ -188,15 +189,6 @@ struct map *get_target_map(const char *target, bool user)
return kernel_get_module_map(target);
}
-static void put_target_map(struct map *map, bool user)
-{
- if (map && user) {
- /* Only the user map needs to be released */
- map__put(map);
- }
-}
-
-
static int convert_exec_to_group(const char *exec, char **result)
{
char *ptr1, *ptr2, *exec_copy;
@@ -268,21 +260,6 @@ static bool kprobe_warn_out_range(const char *symbol, unsigned long address)
}
/*
- * 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.
@@ -296,6 +273,7 @@ static char *find_module_name(const char *module)
Elf_Data *data;
Elf_Scn *sec;
char *mod_name = NULL;
+ int name_offset;
fd = open(module, O_RDONLY);
if (fd < 0)
@@ -317,7 +295,21 @@ static char *find_module_name(const char *module)
if (!data || !data->d_buf)
goto ret_err;
- mod_name = strdup((char *)data->d_buf + MOD_NAME_OFFSET);
+ /*
+ * 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.
+ */
+ if (ehdr.e_ident[EI_CLASS] == ELFCLASS32)
+ name_offset = 12;
+ else /* expect ELFCLASS64 by default */
+ name_offset = 24;
+
+ mod_name = strdup((char *)data->d_buf + name_offset);
ret_err:
elf_end(elf);
@@ -412,7 +404,7 @@ static int find_alternative_probe_point(struct debuginfo *dinfo,
}
out:
- put_target_map(map, uprobes);
+ map__put(map);
return ret;
}
@@ -618,6 +610,67 @@ error:
return ret ? : -ENOENT;
}
+/* Adjust symbol name and address */
+static int post_process_probe_trace_point(struct probe_trace_point *tp,
+ struct map *map, unsigned long offs)
+{
+ struct symbol *sym;
+ u64 addr = tp->address + tp->offset - offs;
+
+ sym = map__find_symbol(map, addr);
+ if (!sym)
+ return -ENOENT;
+
+ if (strcmp(sym->name, tp->symbol)) {
+ /* If we have no realname, use symbol for it */
+ if (!tp->realname)
+ tp->realname = tp->symbol;
+ else
+ free(tp->symbol);
+ tp->symbol = strdup(sym->name);
+ if (!tp->symbol)
+ return -ENOMEM;
+ }
+ tp->offset = addr - sym->start;
+ tp->address -= offs;
+
+ return 0;
+}
+
+/*
+ * Rename DWARF symbols to ELF symbols -- gcc sometimes optimizes functions
+ * and generate new symbols with suffixes such as .constprop.N or .isra.N
+ * etc. Since those symbols are not recorded in DWARF, we have to find
+ * correct generated symbols from offline ELF binary.
+ * For online kernel or uprobes we don't need this because those are
+ * rebased on _text, or already a section relative address.
+ */
+static int
+post_process_offline_probe_trace_events(struct probe_trace_event *tevs,
+ int ntevs, const char *pathname)
+{
+ struct map *map;
+ unsigned long stext = 0;
+ int i, ret = 0;
+
+ /* Prepare a map for offline binary */
+ map = dso__new_map(pathname);
+ if (!map || get_text_start_address(pathname, &stext) < 0) {
+ pr_warning("Failed to get ELF symbols for %s\n", pathname);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < ntevs; i++) {
+ ret = post_process_probe_trace_point(&tevs[i].point,
+ map, stext);
+ if (ret < 0)
+ break;
+ }
+ map__put(map);
+
+ return ret;
+}
+
static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs,
int ntevs, const char *exec)
{
@@ -645,18 +698,31 @@ static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs,
return ret;
}
-static int add_module_to_probe_trace_events(struct probe_trace_event *tevs,
- int ntevs, const char *module)
+static int
+post_process_module_probe_trace_events(struct probe_trace_event *tevs,
+ int ntevs, const char *module,
+ struct debuginfo *dinfo)
{
+ Dwarf_Addr text_offs = 0;
int i, ret = 0;
char *mod_name = NULL;
+ struct map *map;
if (!module)
return 0;
- mod_name = find_module_name(module);
+ map = get_target_map(module, false);
+ if (!map || debuginfo__get_text_offset(dinfo, &text_offs, true) < 0) {
+ pr_warning("Failed to get ELF symbols for %s\n", module);
+ return -EINVAL;
+ }
+ mod_name = find_module_name(module);
for (i = 0; i < ntevs; i++) {
+ ret = post_process_probe_trace_point(&tevs[i].point,
+ map, (unsigned long)text_offs);
+ if (ret < 0)
+ break;
tevs[i].point.module =
strdup(mod_name ? mod_name : module);
if (!tevs[i].point.module) {
@@ -666,6 +732,8 @@ static int add_module_to_probe_trace_events(struct probe_trace_event *tevs,
}
free(mod_name);
+ map__put(map);
+
return ret;
}
@@ -679,7 +747,8 @@ post_process_kernel_probe_trace_events(struct probe_trace_event *tevs,
/* Skip post process if the target is an offline kernel */
if (symbol_conf.ignore_vmlinux_buildid)
- return 0;
+ return post_process_offline_probe_trace_events(tevs, ntevs,
+ symbol_conf.vmlinux_name);
reloc_sym = kernel_get_ref_reloc_sym();
if (!reloc_sym) {
@@ -722,7 +791,7 @@ arch__post_process_probe_trace_events(struct perf_probe_event *pev __maybe_unuse
static int post_process_probe_trace_events(struct perf_probe_event *pev,
struct probe_trace_event *tevs,
int ntevs, const char *module,
- bool uprobe)
+ bool uprobe, struct debuginfo *dinfo)
{
int ret;
@@ -730,7 +799,8 @@ static int post_process_probe_trace_events(struct perf_probe_event *pev,
ret = add_exec_to_probe_trace_events(tevs, ntevs, module);
else if (module)
/* Currently ref_reloc_sym based probe is not for drivers */
- ret = add_module_to_probe_trace_events(tevs, ntevs, module);
+ ret = post_process_module_probe_trace_events(tevs, ntevs,
+ module, dinfo);
else
ret = post_process_kernel_probe_trace_events(tevs, ntevs);
@@ -774,30 +844,27 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev,
}
}
- debuginfo__delete(dinfo);
-
if (ntevs > 0) { /* Succeeded to find trace events */
pr_debug("Found %d probe_trace_events.\n", ntevs);
ret = post_process_probe_trace_events(pev, *tevs, ntevs,
- pev->target, pev->uprobes);
+ pev->target, pev->uprobes, dinfo);
if (ret < 0 || ret == ntevs) {
+ pr_debug("Post processing failed or all events are skipped. (%d)\n", ret);
clear_probe_trace_events(*tevs, ntevs);
zfree(tevs);
+ ntevs = 0;
}
- if (ret != ntevs)
- return ret < 0 ? ret : ntevs;
- ntevs = 0;
- /* Fall through */
}
+ 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;
- }
- /* Error path : ntevs < 0 */
- pr_debug("An error occurred in debuginfo analysis (%d).\n", ntevs);
- if (ntevs < 0) {
+ } else if (ntevs < 0) {
+ /* Error path : ntevs < 0 */
+ pr_debug("An error occurred in debuginfo analysis (%d).\n", ntevs);
if (ntevs == -EBADF)
pr_warning("Warning: No dwarf info found in the vmlinux - "
"please rebuild kernel with CONFIG_DEBUG_INFO=y.\n");
@@ -2869,7 +2936,7 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev,
}
out:
- put_target_map(map, pev->uprobes);
+ map__put(map);
free(syms);
return ret;
@@ -3362,10 +3429,7 @@ int show_available_funcs(const char *target, struct strfilter *_filter,
return ret;
/* Get a symbol map */
- if (user)
- map = dso__new_map(target);
- else
- map = kernel_get_module_map(target);
+ map = get_target_map(target, user);
if (!map) {
pr_err("Failed to get a map for %s\n", (target) ? : "kernel");
return -EINVAL;
@@ -3397,9 +3461,7 @@ int show_available_funcs(const char *target, struct strfilter *_filter,
}
end:
- if (user) {
- map__put(map);
- }
+ map__put(map);
exit_probe_symbol_maps();
return ret;