perf machine: Pass buffer size to machine__mmap_name

Don't blindly assume that the size of the buffer is enough, use
snprintf.

Cc: Avi Kivity <avi@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Zhang, Yanmin <yanmin_zhang@linux.intel.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

4 files changed, 11 insertions, 11 deletions

diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 2f33ca9899bd..7400e5147e13 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -288,7 +288,7 @@ int event__synthesize_kernel_mmap(event__handler_t process,
          */
         struct process_symbol_args args = { .name = symbol_name, };
 
-        mmap_name = machine__mmap_name(machine, name_buff);
+        mmap_name = machine__mmap_name(machine, name_buff, sizeof(name_buff));
         if (machine__is_host(machine)) {
                 /*
                  * kernel uses PERF_RECORD_MISC_USER for user space maps,
@@ -399,7 +399,7 @@ static int event__process_kernel_mmap(event_t *self,
                 goto out_problem;
         }
 
-        machine__mmap_name(machine, kmmap_prefix);
+        machine__mmap_name(machine, kmmap_prefix, sizeof(kmmap_prefix));
         if (machine__is_host(machine))
                 kernel_type = DSO_TYPE_KERNEL;
         else
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index da3d4e826231..ee25ee91504b 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -629,14 +629,14 @@ void machines__process(struct rb_root *self, machine__process_t process, void *d
         }
 }
 
-char *machine__mmap_name(struct machine *self, char *buff)
+char *machine__mmap_name(struct machine *self, char *bf, size_t size)
 {
         if (machine__is_host(self))
-                sprintf(buff, "[%s]", "kernel.kallsyms");
+                snprintf(bf, size, "[%s]", "kernel.kallsyms");
         else if (machine__is_default_guest(self))
-                sprintf(buff, "[%s]", "guest.kernel.kallsyms");
+                snprintf(bf, size, "[%s]", "guest.kernel.kallsyms");
         else
-                sprintf(buff, "[%s.%d]", "guest.kernel.kallsyms", self->pid);
+                snprintf(bf, size, "[%s.%d]", "guest.kernel.kallsyms", self->pid);
 
-        return buff;
+        return bf;
 }
diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
index 4c1c2da704b2..6fabad1fd025 100644
--- a/tools/perf/util/map.h
+++ b/tools/perf/util/map.h
@@ -133,7 +133,7 @@ struct machine *machines__add(struct rb_root *self, pid_t pid,
 struct machine *machines__find_host(struct rb_root *self);
 struct machine *machines__find(struct rb_root *self, pid_t pid);
 struct machine *machines__findnew(struct rb_root *self, pid_t pid);
-char *machine__mmap_name(struct machine *self, char *buff);
+char *machine__mmap_name(struct machine *self, char *bf, size_t size);
 
 /*
  * Default guest kernel is defined by parameter --guestkallsyms
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index dc046368b5cf..c9c0bdd667ac 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1856,7 +1856,7 @@ static int dso__load_guest_kernel_sym(struct dso *self, struct map *map,
 out_try_fixup:
         if (err > 0) {
                 if (kallsyms_filename != NULL) {
-                        machine__mmap_name(machine, path);
+                        machine__mmap_name(machine, path, sizeof(path));
                         dso__set_long_name(self, strdup(path));
                 }
                 map__fixup_start(map);
@@ -1961,8 +1961,8 @@ struct dso *dso__new_kernel(const char *name)
 static struct dso *dso__new_guest_kernel(struct machine *machine,
                                         const char *name)
 {
-        char buff[PATH_MAX];
-        struct dso *self = dso__new(name ?: machine__mmap_name(machine, buff));
+        char bf[PATH_MAX];
+        struct dso *self = dso__new(name ?: machine__mmap_name(machine, bf, sizeof(bf)));
 
         if (self != NULL) {
                 dso__set_short_name(self, "[guest.kernel]");