1 files changed, 158 insertions, 45 deletions

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index a78c8d59a555..c14e1d228e56 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -108,7 +108,6 @@ void exit_probe_symbol_maps(void)
 
 static struct ref_reloc_sym *kernel_get_ref_reloc_sym(struct map **pmap)
 {
-	/* kmap->ref_reloc_sym should be set if host_machine is initialized */
 	struct kmap *kmap;
 	struct map *map = machine__kernel_map(host_machine);
 
@@ -683,8 +682,13 @@ static int post_process_probe_trace_point(struct probe_trace_point *tp,
 	u64 addr = tp->address - offs;
 
 	sym = map__find_symbol(map, addr);
-	if (!sym)
-		return -ENOENT;
+	if (!sym) {
+		/*
+		 * If the address is in the inittext section, map can not
+		 * find it. Ignore it if we are probing offline kernel.
+		 */
+		return (symbol_conf.ignore_vmlinux_buildid) ? 0 : -ENOENT;
+	}
 
 	if (strcmp(sym->name, tp->symbol)) {
 		/* If we have no realname, use symbol for it */
@@ -819,7 +823,10 @@ post_process_kernel_probe_trace_events(struct probe_trace_event *tevs,
 
 	reloc_sym = kernel_get_ref_reloc_sym(&map);
 	if (!reloc_sym) {
-		pr_warning("Relocated base symbol is not found!\n");
+		pr_warning("Relocated base symbol is not found! "
+			   "Check /proc/sys/kernel/kptr_restrict\n"
+			   "and /proc/sys/kernel/perf_event_paranoid. "
+			   "Or run as privileged perf user.\n\n");
 		return -EINVAL;
 	}
 
@@ -2120,19 +2127,55 @@ static int synthesize_probe_trace_arg(struct probe_trace_arg *arg,
 }
 
 static int
-synthesize_uprobe_trace_def(struct probe_trace_event *tev, struct strbuf *buf)
+synthesize_probe_trace_args(struct probe_trace_event *tev, struct strbuf *buf)
+{
+	int i, ret = 0;
+
+	for (i = 0; i < tev->nargs && ret >= 0; i++)
+		ret = synthesize_probe_trace_arg(&tev->args[i], buf);
+
+	return ret;
+}
+
+static int
+synthesize_uprobe_trace_def(struct probe_trace_point *tp, struct strbuf *buf)
 {
-	struct probe_trace_point *tp = &tev->point;
 	int err;
 
+	/* Uprobes must have tp->module */
+	if (!tp->module)
+		return -EINVAL;
+	/*
+	 * If tp->address == 0, then this point must be a
+	 * absolute address uprobe.
+	 * try_to_find_absolute_address() should have made
+	 * tp->symbol to "0x0".
+	 */
+	if (!tp->address && (!tp->symbol || strcmp(tp->symbol, "0x0")))
+		return -EINVAL;
+
+	/* Use the tp->address for uprobes */
 	err = strbuf_addf(buf, "%s:0x%lx", tp->module, tp->address);
 
 	if (err >= 0 && tp->ref_ctr_offset) {
 		if (!uprobe_ref_ctr_is_supported())
-			return -1;
+			return -EINVAL;
 		err = strbuf_addf(buf, "(0x%lx)", tp->ref_ctr_offset);
 	}
-	return err >= 0 ? 0 : -1;
+	return err >= 0 ? 0 : err;
+}
+
+static int
+synthesize_kprobe_trace_def(struct probe_trace_point *tp, struct strbuf *buf)
+{
+	if (!strncmp(tp->symbol, "0x", 2)) {
+		/* Absolute address. See try_to_find_absolute_address() */
+		return strbuf_addf(buf, "%s%s0x%lx", tp->module ?: "",
+				  tp->module ? ":" : "", tp->address);
+	} else {
+		return strbuf_addf(buf, "%s%s%s+%lu", tp->module ?: "",
+				tp->module ? ":" : "", tp->symbol, tp->offset);
+	}
 }
 
 char *synthesize_probe_trace_command(struct probe_trace_event *tev)
@@ -2140,11 +2183,7 @@ char *synthesize_probe_trace_command(struct probe_trace_event *tev)
 	struct probe_trace_point *tp = &tev->point;
 	struct strbuf buf;
 	char *ret = NULL;
-	int i, err;
-
-	/* Uprobes must have tp->module */
-	if (tev->uprobes && !tp->module)
-		return NULL;
+	int err;
 
 	if (strbuf_init(&buf, 32) < 0)
 		return NULL;
@@ -2152,37 +2191,17 @@ char *synthesize_probe_trace_command(struct probe_trace_event *tev)
 	if (strbuf_addf(&buf, "%c:%s/%s ", tp->retprobe ? 'r' : 'p',
 			tev->group, tev->event) < 0)
 		goto error;
-	/*
-	 * If tp->address == 0, then this point must be a
-	 * absolute address uprobe.
-	 * try_to_find_absolute_address() should have made
-	 * tp->symbol to "0x0".
-	 */
-	if (tev->uprobes && !tp->address) {
-		if (!tp->symbol || strcmp(tp->symbol, "0x0"))
-			goto error;
-	}
 
-	/* Use the tp->address for uprobes */
-	if (tev->uprobes) {
-		err = synthesize_uprobe_trace_def(tev, &buf);
-	} else if (!strncmp(tp->symbol, "0x", 2)) {
-		/* Absolute address. See try_to_find_absolute_address() */
-		err = strbuf_addf(&buf, "%s%s0x%lx", tp->module ?: "",
-				  tp->module ? ":" : "", tp->address);
-	} else {
-		err = strbuf_addf(&buf, "%s%s%s+%lu", tp->module ?: "",
-				tp->module ? ":" : "", tp->symbol, tp->offset);
-	}
-
-	if (err)
-		goto error;
+	if (tev->uprobes)
+		err = synthesize_uprobe_trace_def(tp, &buf);
+	else
+		err = synthesize_kprobe_trace_def(tp, &buf);
 
-	for (i = 0; i < tev->nargs; i++)
-		if (synthesize_probe_trace_arg(&tev->args[i], &buf) < 0)
-			goto error;
+	if (err >= 0)
+		err = synthesize_probe_trace_args(tev, &buf);
 
-	ret = strbuf_detach(&buf, NULL);
+	if (err >= 0)
+		ret = strbuf_detach(&buf, NULL);
 error:
 	strbuf_release(&buf);
 	return ret;
@@ -2934,7 +2953,7 @@ static int find_probe_functions(struct map *map, char *name,
 	bool cut_version = true;
 
 	if (map__load(map) < 0)
-		return 0;
+		return -EACCES;	/* Possible permission error to load symbols */
 
 	/* If user gives a version, don't cut off the version from symbols */
 	if (strchr(name, '@'))
@@ -2973,6 +2992,17 @@ void __weak arch__fix_tev_from_maps(struct perf_probe_event *pev __maybe_unused,
 				struct map *map __maybe_unused,
 				struct symbol *sym __maybe_unused) { }
 
+
+static void pr_kallsyms_access_error(void)
+{
+	pr_err("Please ensure you can read the /proc/kallsyms symbol addresses.\n"
+	       "If /proc/sys/kernel/kptr_restrict is '2', you can not read\n"
+	       "kernel symbol addresses even if you are a superuser. Please change\n"
+	       "it to '1'. If kptr_restrict is '1', the superuser can read the\n"
+	       "symbol addresses.\n"
+	       "In that case, please run this command again with sudo.\n");
+}
+
 /*
  * Find probe function addresses from map.
  * Return an error or the number of found probe_trace_event
@@ -3009,8 +3039,16 @@ 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");
+		if (num_matched_functions == -EACCES) {
+			pr_err("Failed to load symbols from %s\n",
+			       pev->target ?: "/proc/kallsyms");
+			if (pev->target)
+				pr_err("Please ensure the file is not stripped.\n");
+			else
+				pr_kallsyms_access_error();
+		} else
+			pr_err("Failed to find symbol %s in %s\n", pp->function,
+				pev->target ? : "kernel");
 		ret = -ENOENT;
 		goto out;
 	} else if (num_matched_functions > probe_conf.max_probes) {
@@ -3025,7 +3063,10 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev,
 			(!pp->retprobe || kretprobe_offset_is_supported())) {
 		reloc_sym = kernel_get_ref_reloc_sym(NULL);
 		if (!reloc_sym) {
-			pr_warning("Relocated base symbol is not found!\n");
+			pr_warning("Relocated base symbol is not found! "
+				   "Check /proc/sys/kernel/kptr_restrict\n"
+				   "and /proc/sys/kernel/perf_event_paranoid. "
+				   "Or run as privileged perf user.\n\n");
 			ret = -EINVAL;
 			goto out;
 		}
@@ -3523,6 +3564,78 @@ int show_probe_trace_events(struct perf_probe_event *pevs, int npevs)
 	return ret;
 }
 
+static int show_bootconfig_event(struct probe_trace_event *tev)
+{
+	struct probe_trace_point *tp = &tev->point;
+	struct strbuf buf;
+	char *ret = NULL;
+	int err;
+
+	if (strbuf_init(&buf, 32) < 0)
+		return -ENOMEM;
+
+	err = synthesize_kprobe_trace_def(tp, &buf);
+	if (err >= 0)
+		err = synthesize_probe_trace_args(tev, &buf);
+	if (err >= 0)
+		ret = strbuf_detach(&buf, NULL);
+	strbuf_release(&buf);
+
+	if (ret) {
+		printf("'%s'", ret);
+		free(ret);
+	}
+
+	return err;
+}
+
+int show_bootconfig_events(struct perf_probe_event *pevs, int npevs)
+{
+	struct strlist *namelist = strlist__new(NULL, NULL);
+	struct probe_trace_event *tev;
+	struct perf_probe_event *pev;
+	char *cur_name = NULL;
+	int i, j, ret = 0;
+
+	if (!namelist)
+		return -ENOMEM;
+
+	for (j = 0; j < npevs && !ret; j++) {
+		pev = &pevs[j];
+		if (pev->group && strcmp(pev->group, "probe"))
+			pr_warning("WARN: Group name %s is ignored\n", pev->group);
+		if (pev->uprobes) {
+			pr_warning("ERROR: Bootconfig doesn't support uprobes\n");
+			ret = -EINVAL;
+			break;
+		}
+		for (i = 0; i < pev->ntevs && !ret; i++) {
+			tev = &pev->tevs[i];
+			/* Skip if the symbol is out of .text or blacklisted */
+			if (!tev->point.symbol && !pev->uprobes)
+				continue;
+
+			/* Set new name for tev (and update namelist) */
+			ret = probe_trace_event__set_name(tev, pev,
+							  namelist, true);
+			if (ret)
+				break;
+
+			if (!cur_name || strcmp(cur_name, tev->event)) {
+				printf("%sftrace.event.kprobes.%s.probe = ",
+					cur_name ? "\n" : "", tev->event);
+				cur_name = tev->event;
+			} else
+				printf(", ");
+			ret = show_bootconfig_event(tev);
+		}
+	}
+	printf("\n");
+	strlist__delete(namelist);
+
+	return ret;
+}
+
 int apply_perf_probe_events(struct perf_probe_event *pevs, int npevs)
 {
 	int i, ret = 0;