[RFC PATCH 2/8] perf probe: Check the return value of strbuf APIs
From: Masami Hiramatsu
Date: Fri Apr 29 2016 - 10:47:02 EST
Check the return value of strbuf APIs in perf-probe
related code, so that it can handle errors in strbuf.
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
tools/perf/util/dwarf-aux.c | 50 +++++-------
tools/perf/util/probe-event.c | 167 +++++++++++++++++++++++-----------------
tools/perf/util/probe-finder.c | 30 ++++---
3 files changed, 137 insertions(+), 110 deletions(-)
diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c
index aea189b..8c8b4c1 100644
--- a/tools/perf/util/dwarf-aux.c
+++ b/tools/perf/util/dwarf-aux.c
@@ -915,8 +915,7 @@ int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
tmp = "*";
else if (tag == DW_TAG_subroutine_type) {
/* Function pointer */
- strbuf_add(buf, "(function_type)", 15);
- return 0;
+ return strbuf_add(buf, "(function_type)", 15);
} else {
if (!dwarf_diename(&type))
return -ENOENT;
@@ -927,14 +926,10 @@ int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
else if (tag == DW_TAG_enumeration_type)
tmp = "enum ";
/* Write a base name */
- strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type));
- return 0;
+ return strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type));
}
ret = die_get_typename(&type, buf);
- if (ret == 0)
- strbuf_addstr(buf, tmp);
-
- return ret;
+ return ret ? ret : strbuf_addstr(buf, tmp);
}
/**
@@ -951,12 +946,10 @@ int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
ret = die_get_typename(vr_die, buf);
if (ret < 0) {
pr_debug("Failed to get type, make it unknown.\n");
- strbuf_add(buf, " (unknown_type)", 14);
+ ret = strbuf_add(buf, " (unknown_type)", 14);
}
- strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
-
- return 0;
+ return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
}
#ifdef HAVE_DWARF_GETLOCATIONS
@@ -998,23 +991,23 @@ static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
goto out;
}
- while ((offset = dwarf_ranges(&scopes[1], offset, &base,
- &start, &end)) > 0) {
+ while (!ret && (offset = dwarf_ranges(&scopes[1], offset, &base,
+ &start, &end)) > 0) {
start -= entry;
end -= entry;
if (first) {
- strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
- name, start, end);
+ ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
+ name, start, end);
first = false;
} else {
- strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
- start, end);
+ ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
+ start, end);
}
}
- if (!first)
- strbuf_add(buf, "]>", 2);
+ if (!ret && !first)
+ ret = strbuf_add(buf, "]>", 2);
out:
free(scopes);
@@ -1054,9 +1047,8 @@ int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
return -EINVAL;
- while ((offset = dwarf_getlocations(
- &attr, offset, &base,
- &start, &end, &op, &nops)) > 0) {
+ while (!ret && (offset = dwarf_getlocations(&attr, offset, &base,
+ &start, &end, &op, &nops)) > 0) {
if (start == 0) {
/* Single Location Descriptions */
ret = die_get_var_innermost_scope(sp_die, vr_die, buf);
@@ -1067,17 +1059,17 @@ int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
start -= entry;
end -= entry;
if (first) {
- strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
- name, start, end);
+ ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
+ name, start, end);
first = false;
} else {
- strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
- start, end);
+ ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
+ start, end);
}
}
- if (!first)
- strbuf_add(buf, "]>", 2);
+ if (!ret && !first)
+ ret = strbuf_add(buf, "]>", 2);
return ret;
}
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index e9762e5..c465a5d 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1732,28 +1732,36 @@ char *synthesize_perf_probe_arg(struct perf_probe_arg *pa)
{
struct perf_probe_arg_field *field = pa->field;
struct strbuf buf;
- char *ret;
+ char *ret = NULL;
+ int err;
+
+ if (strbuf_init(&buf, 64) < 0)
+ return NULL;
- strbuf_init(&buf, 64);
if (pa->name && pa->var)
- strbuf_addf(&buf, "%s=%s", pa->name, pa->var);
+ err = strbuf_addf(&buf, "%s=%s", pa->name, pa->var);
else
- strbuf_addstr(&buf, pa->name ?: pa->var);
-
- while (field) {
+ err = strbuf_addstr(&buf, pa->name ?: pa->var);
+ if (err)
+ goto out;
+ while (field && !err) {
if (field->name[0] == '[')
- strbuf_addstr(&buf, field->name);
+ err = strbuf_addstr(&buf, field->name);
else
- strbuf_addf(&buf, "%s%s", field->ref ? "->" : ".",
- field->name);
+ err = strbuf_addf(&buf, "%s%s", field->ref ? "->" : ".",
+ field->name);
field = field->next;
}
+ if (err)
+ goto out;
if (pa->type)
- strbuf_addf(&buf, ":%s", pa->type);
+ if (strbuf_addf(&buf, ":%s", pa->type) < 0)
+ goto out;
ret = strbuf_detach(&buf, NULL);
-
+out:
+ strbuf_release(&buf);
return ret;
}
@@ -1761,18 +1769,23 @@ char *synthesize_perf_probe_arg(struct perf_probe_arg *pa)
char *synthesize_perf_probe_point(struct perf_probe_point *pp)
{
struct strbuf buf;
- char *tmp;
- int len;
+ char *tmp, *ret = NULL;
+ int len, err = 0;
+
+ if (strbuf_init(&buf, 64) < 0)
+ return NULL;
- strbuf_init(&buf, 64);
if (pp->function) {
- strbuf_addstr(&buf, pp->function);
+ if (strbuf_addstr(&buf, pp->function) < 0)
+ goto out;
if (pp->offset)
- strbuf_addf(&buf, "+%lu", pp->offset);
+ err = strbuf_addf(&buf, "+%lu", pp->offset);
else if (pp->line)
- strbuf_addf(&buf, ":%d", pp->line);
+ err = strbuf_addf(&buf, ":%d", pp->line);
else if (pp->retprobe)
- strbuf_addstr(&buf, "%return");
+ err = strbuf_addstr(&buf, "%return");
+ if (err)
+ goto out;
}
if (pp->file) {
tmp = pp->file;
@@ -1781,70 +1794,76 @@ char *synthesize_perf_probe_point(struct perf_probe_point *pp)
tmp = strchr(pp->file + len - 30, '/');
tmp = tmp ? tmp + 1 : pp->file + len - 30;
}
- strbuf_addf(&buf, "@%s", tmp);
- if (!pp->function && pp->line)
- strbuf_addf(&buf, ":%d", pp->line);
+ err = strbuf_addf(&buf, "@%s", tmp);
+ if (!err && !pp->function && pp->line)
+ err = strbuf_addf(&buf, ":%d", pp->line);
}
-
- return strbuf_detach(&buf, NULL);
+ if (!err)
+ ret = strbuf_detach(&buf, NULL);
+out:
+ strbuf_release(&buf);
+ return ret;
}
char *synthesize_perf_probe_command(struct perf_probe_event *pev)
{
struct strbuf buf;
- char *tmp;
+ char *tmp, *ret = NULL;
int i;
- strbuf_init(&buf, 64);
+ if (strbuf_init(&buf, 64))
+ return NULL;
+
if (pev->event)
- strbuf_addf(&buf, "%s:%s=", pev->group ?: PERFPROBE_GROUP,
- pev->event);
+ if (strbuf_addf(&buf, "%s:%s=", pev->group ?: PERFPROBE_GROUP,
+ pev->event) < 0)
+ goto out;
tmp = synthesize_perf_probe_point(&pev->point);
- if (!tmp)
+ if (!tmp || strbuf_addstr(&buf, tmp) < 0)
goto out;
- strbuf_addstr(&buf, tmp);
free(tmp);
for (i = 0; i < pev->nargs; i++) {
tmp = synthesize_perf_probe_arg(pev->args + i);
- if (!tmp)
+ if (!tmp || strbuf_addf(&buf, " %s", tmp) < 0)
goto out;
- strbuf_addf(&buf, " %s", tmp);
free(tmp);
}
- tmp = strbuf_detach(&buf, NULL);
+ ret = strbuf_detach(&buf, NULL);
out:
strbuf_release(&buf);
- return tmp;
+ return ret;
}
static int __synthesize_probe_trace_arg_ref(struct probe_trace_arg_ref *ref,
struct strbuf *buf, int depth)
{
+ int err;
if (ref->next) {
depth = __synthesize_probe_trace_arg_ref(ref->next, buf,
depth + 1);
if (depth < 0)
- goto out;
+ return depth;
}
- strbuf_addf(buf, "%+ld(", ref->offset);
-out:
- return depth;
+ err = strbuf_addf(buf, "%+ld(", ref->offset);
+ return (err < 0) ? err : depth;
}
static int synthesize_probe_trace_arg(struct probe_trace_arg *arg,
struct strbuf *buf)
{
struct probe_trace_arg_ref *ref = arg->ref;
- int depth = 0;
+ int depth = 0, err;
/* Argument name or separator */
if (arg->name)
- strbuf_addf(buf, " %s=", arg->name);
+ err = strbuf_addf(buf, " %s=", arg->name);
else
- strbuf_addch(buf, ' ');
+ err = strbuf_addch(buf, ' ');
+ if (err)
+ return err;
/* Special case: @XXX */
if (arg->value[0] == '@' && arg->ref)
@@ -1859,18 +1878,19 @@ static int synthesize_probe_trace_arg(struct probe_trace_arg *arg,
/* Print argument value */
if (arg->value[0] == '@' && arg->ref)
- strbuf_addf(buf, "%s%+ld", arg->value, arg->ref->offset);
+ err = strbuf_addf(buf, "%s%+ld", arg->value, arg->ref->offset);
else
- strbuf_addstr(buf, arg->value);
+ err = strbuf_addstr(buf, arg->value);
/* Closing */
- while (depth--)
- strbuf_addch(buf, ')');
+ while (depth-- && !err)
+ err = strbuf_addch(buf, ')');
+
/* Print argument type */
- if (arg->type)
- strbuf_addf(buf, ":%s", arg->type);
+ if (arg->type && !err)
+ err = strbuf_addf(buf, ":%s", arg->type);
- return 0;
+ return err;
}
char *synthesize_probe_trace_command(struct probe_trace_event *tev)
@@ -1878,15 +1898,18 @@ 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;
+ int i, err;
/* Uprobes must have tp->module */
if (tev->uprobes && !tp->module)
return NULL;
- strbuf_init(&buf, 32);
- strbuf_addf(&buf, "%c:%s/%s ", tp->retprobe ? 'r' : 'p',
- tev->group, tev->event);
+ if (strbuf_init(&buf, 32) < 0)
+ return NULL;
+
+ 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.
@@ -1900,14 +1923,16 @@ char *synthesize_probe_trace_command(struct probe_trace_event *tev)
/* Use the tp->address for uprobes */
if (tev->uprobes)
- strbuf_addf(&buf, "%s:0x%lx", tp->module, tp->address);
+ err = strbuf_addf(&buf, "%s:0x%lx", tp->module, tp->address);
else if (!strncmp(tp->symbol, "0x", 2))
/* Absolute address. See try_to_find_absolute_address() */
- strbuf_addf(&buf, "%s%s0x%lx", tp->module ?: "",
- tp->module ? ":" : "", tp->address);
+ err = strbuf_addf(&buf, "%s%s0x%lx", tp->module ?: "",
+ tp->module ? ":" : "", tp->address);
else
- strbuf_addf(&buf, "%s%s%s+%lu", tp->module ?: "",
- tp->module ? ":" : "", tp->symbol, tp->offset);
+ err = strbuf_addf(&buf, "%s%s%s+%lu", tp->module ?: "",
+ tp->module ? ":" : "", tp->symbol, tp->offset);
+ if (err)
+ goto error;
for (i = 0; i < tev->nargs; i++)
if (synthesize_probe_trace_arg(&tev->args[i], &buf) < 0)
@@ -2021,14 +2046,15 @@ static int convert_to_perf_probe_event(struct probe_trace_event *tev,
if (tev->args[i].name)
pev->args[i].name = strdup(tev->args[i].name);
else {
- strbuf_init(&buf, 32);
+ if ((ret = strbuf_init(&buf, 32)) < 0)
+ goto error;
ret = synthesize_probe_trace_arg(&tev->args[i], &buf);
pev->args[i].name = strbuf_detach(&buf, NULL);
}
if (pev->args[i].name == NULL && ret >= 0)
ret = -ENOMEM;
}
-
+error:
if (ret < 0)
clear_perf_probe_event(pev);
@@ -2274,37 +2300,40 @@ static int perf_probe_event__sprintf(const char *group, const char *event,
const char *module,
struct strbuf *result)
{
- int i;
+ int i, ret;
char *buf;
if (asprintf(&buf, "%s:%s", group, event) < 0)
return -errno;
- strbuf_addf(result, " %-20s (on ", buf);
+ ret = strbuf_addf(result, " %-20s (on ", buf);
free(buf);
+ if (ret)
+ return ret;
/* Synthesize only event probe point */
buf = synthesize_perf_probe_point(&pev->point);
if (!buf)
return -ENOMEM;
- strbuf_addstr(result, buf);
+ ret = strbuf_addstr(result, buf);
free(buf);
- if (module)
- strbuf_addf(result, " in %s", module);
+ if (!ret && module)
+ ret = strbuf_addf(result, " in %s", module);
- if (pev->nargs > 0) {
- strbuf_add(result, " with", 5);
- for (i = 0; i < pev->nargs; i++) {
+ if (!ret && pev->nargs > 0) {
+ ret = strbuf_add(result, " with", 5);
+ for (i = 0; !ret && i < pev->nargs; i++) {
buf = synthesize_perf_probe_arg(&pev->args[i]);
if (!buf)
return -ENOMEM;
- strbuf_addf(result, " %s", buf);
+ ret = strbuf_addf(result, " %s", buf);
free(buf);
}
}
- strbuf_addch(result, ')');
+ if (!ret)
+ ret = strbuf_addch(result, ')');
- return 0;
+ return ret;
}
/* Show an event */
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 9f68875..1259839 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -1294,6 +1294,7 @@ static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
{
struct available_var_finder *af = data;
struct variable_list *vl;
+ struct strbuf buf = STRBUF_INIT;
int tag, ret;
vl = &af->vls[af->nvls - 1];
@@ -1307,25 +1308,26 @@ static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
if (ret == 0 || ret == -ERANGE) {
int ret2;
bool externs = !af->child;
- struct strbuf buf;
- strbuf_init(&buf, 64);
+ if (strbuf_init(&buf, 64) < 0)
+ goto error;
if (probe_conf.show_location_range) {
- if (!externs) {
- if (ret)
- strbuf_add(&buf, "[INV]\t", 6);
- else
- strbuf_add(&buf, "[VAL]\t", 6);
- } else
- strbuf_add(&buf, "[EXT]\t", 6);
+ if (!externs)
+ ret2 = strbuf_add(&buf,
+ ret ? "[INV]\t" : "[VAL]\t", 6);
+ else
+ ret2 = strbuf_add(&buf, "[EXT]\t", 6);
+ if (ret2)
+ goto error;
}
ret2 = die_get_varname(die_mem, &buf);
if (!ret2 && probe_conf.show_location_range &&
!externs) {
- strbuf_addch(&buf, '\t');
+ if (strbuf_addch(&buf, '\t') < 0)
+ goto error;
ret2 = die_get_var_range(&af->pf.sp_die,
die_mem, &buf);
}
@@ -1334,8 +1336,8 @@ static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
if (ret2 == 0) {
strlist__add(vl->vars,
strbuf_detach(&buf, NULL));
- } else
- strbuf_release(&buf);
+ }
+ strbuf_release(&buf);
}
}
@@ -1343,6 +1345,10 @@ static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
return DIE_FIND_CB_CONTINUE;
else
return DIE_FIND_CB_SIBLING;
+error:
+ strbuf_release(&buf);
+ pr_debug("Error in strbuf\n");
+ return DIE_FIND_CB_END;
}
/* Add a found vars into available variables list */