perf probe: Check the return value of strbuf APIs

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@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160510054707.6158.69861.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c
index aea189b..a347b19 100644 (file)
--- 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
@@ -999,22 +992,24 @@ static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
        }
 
        while ((offset = dwarf_ranges(&scopes[1], offset, &base,
-                               &start, &end)) > 0) {
+                                       &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 (ret < 0)
+                       goto out;
        }
 
        if (!first)
-               strbuf_add(buf, "]>", 2);
+               ret = strbuf_add(buf, "]>", 2);
 
 out:
        free(scopes);
@@ -1054,31 +1049,32 @@ 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 ((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);
-                       return ret;
+                       goto out;
                }
 
                /* Location Lists */
                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 (ret < 0)
+                       goto out;
        }
 
        if (!first)
-               strbuf_add(buf, "]>", 2);
-
+               ret = strbuf_add(buf, "]>", 2);
+out:
        return ret;
 }
 #else

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index c82c625..74401a2 100644 (file)
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1677,28 +1677,37 @@ 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);
+               err = strbuf_addstr(&buf, pa->name ?: pa->var);
+       if (err)
+               goto out;
 
        while (field) {
                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;
 }
 
@@ -1706,18 +1715,23 @@ char *synthesize_perf_probe_arg(struct perf_probe_arg *pa)
 static 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;
@@ -1726,12 +1740,15 @@ static 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;
 }
 
 #if 0
@@ -1762,28 +1779,30 @@ char *synthesize_perf_probe_command(struct perf_probe_event *pev)
 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)
@@ -1798,18 +1817,19 @@ 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 (!err && depth--)
+               err = strbuf_addch(buf, ')');
+
        /* Print argument type */
-       if (arg->type)
-               strbuf_addf(buf, ":%s", arg->type);
+       if (!err && arg->type)
+               err = strbuf_addf(buf, ":%s", arg->type);
 
-       return 0;
+       return err;
 }
 
 char *synthesize_probe_trace_command(struct probe_trace_event *tev)
@@ -1817,15 +1837,18 @@ 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.
@@ -1839,14 +1862,16 @@ 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)
@@ -1960,14 +1985,15 @@ 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);
 
@@ -2140,37 +2166,40 @@ 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 (file)
--- 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 */