[PATCH v5 03/23] perf build-id: Change sprintf functions to snprintf

Ian Rogers posted 23 patches 3 months, 1 week ago
There is a newer version of this series
[PATCH v5 03/23] perf build-id: Change sprintf functions to snprintf
Posted by Ian Rogers 3 months, 1 week ago
Pass in a size argument rather than implying all build id strings must
be SBUILD_ID_SIZE.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/builtin-buildid-cache.c            | 12 +++----
 tools/perf/builtin-buildid-list.c             |  6 ++--
 tools/perf/util/build-id.c                    | 33 ++++++++-----------
 tools/perf/util/build-id.h                    |  6 ++--
 tools/perf/util/disasm.c                      |  2 +-
 tools/perf/util/dso.c                         |  4 +--
 tools/perf/util/dsos.c                        |  2 +-
 tools/perf/util/event.c                       |  2 +-
 tools/perf/util/header.c                      |  2 +-
 tools/perf/util/map.c                         |  2 +-
 tools/perf/util/probe-file.c                  |  4 +--
 .../scripting-engines/trace-event-python.c    |  7 ++--
 tools/perf/util/symbol.c                      |  2 +-
 13 files changed, 38 insertions(+), 46 deletions(-)

diff --git a/tools/perf/builtin-buildid-cache.c b/tools/perf/builtin-buildid-cache.c
index b0511d16aeb6..3f7739b21148 100644
--- a/tools/perf/builtin-buildid-cache.c
+++ b/tools/perf/builtin-buildid-cache.c
@@ -31,7 +31,7 @@
 #include <linux/string.h>
 #include <linux/err.h>
 
-static int build_id_cache__kcore_buildid(const char *proc_dir, char *sbuildid)
+static int build_id_cache__kcore_buildid(const char *proc_dir, char *sbuildid, size_t sbuildid_size)
 {
 	char root_dir[PATH_MAX];
 	char *p;
@@ -42,7 +42,7 @@ static int build_id_cache__kcore_buildid(const char *proc_dir, char *sbuildid)
 	if (!p)
 		return -1;
 	*p = '\0';
-	return sysfs__sprintf_build_id(root_dir, sbuildid);
+	return sysfs__snprintf_build_id(root_dir, sbuildid, sbuildid_size);
 }
 
 static int build_id_cache__kcore_dir(char *dir, size_t sz)
@@ -128,7 +128,7 @@ static int build_id_cache__add_kcore(const char *filename, bool force)
 		return -1;
 	*p = '\0';
 
-	if (build_id_cache__kcore_buildid(from_dir, sbuildid) < 0)
+	if (build_id_cache__kcore_buildid(from_dir, sbuildid, sizeof(sbuildid)) < 0)
 		return -1;
 
 	scnprintf(to_dir, sizeof(to_dir), "%s/%s/%s",
@@ -187,7 +187,7 @@ static int build_id_cache__add_file(const char *filename, struct nsinfo *nsi)
 		return -1;
 	}
 
-	build_id__sprintf(&bid, sbuild_id);
+	build_id__snprintf(&bid, sbuild_id, sizeof(sbuild_id));
 	err = build_id_cache__add_s(sbuild_id, filename, nsi,
 				    false, false);
 	pr_debug("Adding %s %s: %s\n", sbuild_id, filename,
@@ -211,7 +211,7 @@ static int build_id_cache__remove_file(const char *filename, struct nsinfo *nsi)
 		return -1;
 	}
 
-	build_id__sprintf(&bid, sbuild_id);
+	build_id__snprintf(&bid, sbuild_id, sizeof(sbuild_id));
 	err = build_id_cache__remove_s(sbuild_id);
 	pr_debug("Removing %s %s: %s\n", sbuild_id, filename,
 		 err ? "FAIL" : "Ok");
@@ -317,7 +317,7 @@ static int build_id_cache__update_file(const char *filename, struct nsinfo *nsi)
 	}
 	err = 0;
 
-	build_id__sprintf(&bid, sbuild_id);
+	build_id__snprintf(&bid, sbuild_id, sizeof(sbuild_id));
 	if (build_id_cache__cached(sbuild_id))
 		err = build_id_cache__remove_s(sbuild_id);
 
diff --git a/tools/perf/builtin-buildid-list.c b/tools/perf/builtin-buildid-list.c
index 52dfacaff8e3..ba8ba0303920 100644
--- a/tools/perf/builtin-buildid-list.c
+++ b/tools/perf/builtin-buildid-list.c
@@ -31,7 +31,7 @@ static int buildid__map_cb(struct map *map, void *arg __maybe_unused)
 
 	memset(bid_buf, 0, sizeof(bid_buf));
 	if (dso__has_build_id(dso))
-		build_id__sprintf(dso__bid_const(dso), bid_buf);
+		build_id__snprintf(dso__bid_const(dso), bid_buf, sizeof(bid_buf));
 	printf("%s %16" PRIx64 " %16" PRIx64, bid_buf, map__start(map), map__end(map));
 	if (dso_long_name != NULL)
 		printf(" %s", dso_long_name);
@@ -57,7 +57,7 @@ static int sysfs__fprintf_build_id(FILE *fp)
 	char sbuild_id[SBUILD_ID_SIZE];
 	int ret;
 
-	ret = sysfs__sprintf_build_id("/", sbuild_id);
+	ret = sysfs__snprintf_build_id("/", sbuild_id, sizeof(sbuild_id));
 	if (ret != sizeof(sbuild_id))
 		return ret < 0 ? ret : -EINVAL;
 
@@ -69,7 +69,7 @@ static int filename__fprintf_build_id(const char *name, FILE *fp)
 	char sbuild_id[SBUILD_ID_SIZE];
 	int ret;
 
-	ret = filename__sprintf_build_id(name, sbuild_id);
+	ret = filename__snprintf_build_id(name, sbuild_id, sizeof(sbuild_id));
 	if (ret != sizeof(sbuild_id))
 		return ret < 0 ? ret : -EINVAL;
 
diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 5bc2040bdd0d..aa35dceace90 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -67,24 +67,17 @@ int build_id__mark_dso_hit(const struct perf_tool *tool __maybe_unused,
 	return 0;
 }
 
-int build_id__sprintf(const struct build_id *build_id, char *bf)
+int build_id__snprintf(const struct build_id *build_id, char *bf, size_t bf_size)
 {
-	char *bid = bf;
-	const u8 *raw = build_id->data;
-	size_t i;
-
-	bf[0] = 0x0;
+	size_t offs = 0;
 
-	for (i = 0; i < build_id->size; ++i) {
-		sprintf(bid, "%02x", *raw);
-		++raw;
-		bid += 2;
-	}
+	for (size_t i = 0; i < build_id->size && offs < bf_size; ++i)
+		offs += snprintf(bf + offs, bf_size - offs, "%02x", build_id->data[i]);
 
-	return (bid - bf) + 1;
+	return offs;
 }
 
-int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
+int sysfs__snprintf_build_id(const char *root_dir, char *sbuild_id, size_t sbuild_id_size)
 {
 	char notes[PATH_MAX];
 	struct build_id bid;
@@ -99,10 +92,10 @@ int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
 	if (ret < 0)
 		return ret;
 
-	return build_id__sprintf(&bid, sbuild_id);
+	return build_id__snprintf(&bid, sbuild_id, sbuild_id_size);
 }
 
-int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
+int filename__snprintf_build_id(const char *pathname, char *sbuild_id, size_t sbuild_id_size)
 {
 	struct build_id bid;
 	int ret;
@@ -111,7 +104,7 @@ int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
 	if (ret < 0)
 		return ret;
 
-	return build_id__sprintf(&bid, sbuild_id);
+	return build_id__snprintf(&bid, sbuild_id, sbuild_id_size);
 }
 
 /* asnprintf consolidates asprintf and snprintf */
@@ -212,9 +205,9 @@ static bool build_id_cache__valid_id(char *sbuild_id)
 		return false;
 
 	if (!strcmp(pathname, DSO__NAME_KALLSYMS))
-		ret = sysfs__sprintf_build_id("/", real_sbuild_id);
+		ret = sysfs__snprintf_build_id("/", real_sbuild_id, sizeof(real_sbuild_id));
 	else if (pathname[0] == '/')
-		ret = filename__sprintf_build_id(pathname, real_sbuild_id);
+		ret = filename__snprintf_build_id(pathname, real_sbuild_id, sizeof(real_sbuild_id));
 	else
 		ret = -EINVAL;	/* Should we support other special DSO cache? */
 	if (ret >= 0)
@@ -243,7 +236,7 @@ char *__dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
 	if (!dso__has_build_id(dso))
 		return NULL;
 
-	build_id__sprintf(dso__bid_const(dso), sbuild_id);
+	build_id__snprintf(dso__bid_const(dso), sbuild_id, sizeof(sbuild_id));
 	linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
 	if (!linkname)
 		return NULL;
@@ -769,7 +762,7 @@ static int build_id_cache__add_b(const struct build_id *bid,
 {
 	char sbuild_id[SBUILD_ID_SIZE];
 
-	build_id__sprintf(bid, sbuild_id);
+	build_id__snprintf(bid, sbuild_id, sizeof(sbuild_id));
 
 	return __build_id_cache__add_s(sbuild_id, name, nsi, is_kallsyms,
 				       is_vdso, proper_name, root_dir);
diff --git a/tools/perf/util/build-id.h b/tools/perf/util/build-id.h
index e3e0a446ff0c..47e621cebe1b 100644
--- a/tools/perf/util/build-id.h
+++ b/tools/perf/util/build-id.h
@@ -21,10 +21,10 @@ struct feat_fd;
 struct nsinfo;
 
 void build_id__init(struct build_id *bid, const u8 *data, size_t size);
-int build_id__sprintf(const struct build_id *build_id, char *bf);
+int build_id__snprintf(const struct build_id *build_id, char *bf, size_t bf_size);
 bool build_id__is_defined(const struct build_id *bid);
-int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id);
-int filename__sprintf_build_id(const char *pathname, char *sbuild_id);
+int sysfs__snprintf_build_id(const char *root_dir, char *sbuild_id, size_t sbuild_id_size);
+int filename__snprintf_build_id(const char *pathname, char *sbuild_id, size_t sbuild_id_size);
 char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf,
 				    size_t size);
 
diff --git a/tools/perf/util/disasm.c b/tools/perf/util/disasm.c
index 8f0eb56c6fc6..96e6a5d6eacc 100644
--- a/tools/perf/util/disasm.c
+++ b/tools/perf/util/disasm.c
@@ -1218,7 +1218,7 @@ int symbol__strerror_disassemble(struct map_symbol *ms, int errnum, char *buf, s
 		char *build_id_msg = NULL;
 
 		if (dso__has_build_id(dso)) {
-			build_id__sprintf(dso__bid(dso), bf + 15);
+			build_id__snprintf(dso__bid(dso), bf + 15, sizeof(bf) - 15);
 			build_id_msg = bf;
 		}
 		scnprintf(buf, buflen,
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 057fcf4225ac..97664610c37e 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -217,7 +217,7 @@ int dso__read_binary_type_filename(const struct dso *dso,
 			break;
 		}
 
-		build_id__sprintf(dso__bid_const(dso), build_id_hex);
+		build_id__snprintf(dso__bid_const(dso), build_id_hex, sizeof(build_id_hex));
 		len = __symbol__join_symfs(filename, size, "/usr/lib/debug/.build-id/");
 		snprintf(filename + len, size - len, "%.2s/%s.debug",
 			 build_id_hex, build_id_hex + 2);
@@ -1704,7 +1704,7 @@ static size_t dso__fprintf_buildid(struct dso *dso, FILE *fp)
 {
 	char sbuild_id[SBUILD_ID_SIZE];
 
-	build_id__sprintf(dso__bid(dso), sbuild_id);
+	build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id));
 	return fprintf(fp, "%s", sbuild_id);
 }
 
diff --git a/tools/perf/util/dsos.c b/tools/perf/util/dsos.c
index 4d213017d202..47538273915d 100644
--- a/tools/perf/util/dsos.c
+++ b/tools/perf/util/dsos.c
@@ -373,7 +373,7 @@ static int dsos__fprintf_buildid_cb(struct dso *dso, void *data)
 
 	if (args->skip && args->skip(dso, args->parm))
 		return 0;
-	build_id__sprintf(dso__bid(dso), sbuild_id);
+	build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id));
 	args->ret += fprintf(args->fp, "%-40s %s\n", sbuild_id, dso__long_name(dso));
 	return 0;
 }
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 14b0d3689137..fcf44149feb2 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -334,7 +334,7 @@ size_t perf_event__fprintf_mmap2(union perf_event *event, FILE *fp)
 
 		build_id__init(&bid, event->mmap2.build_id,
 			       event->mmap2.build_id_size);
-		build_id__sprintf(&bid, sbuild_id);
+		build_id__snprintf(&bid, sbuild_id, sizeof(sbuild_id));
 
 		return fprintf(fp, " %d/%d: [%#" PRI_lx64 "(%#" PRI_lx64 ") @ %#" PRI_lx64
 				   " <%s>]: %c%c%c%c %s\n",
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 2dea35237e81..44941b3adddd 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -2291,7 +2291,7 @@ static int __event_process_build_id(struct perf_record_header_build_id *bev,
 			free(m.name);
 		}
 
-		build_id__sprintf(dso__bid(dso), sbuild_id);
+		build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id));
 		pr_debug("build id event received for %s: %s [%zu]\n",
 			 dso__long_name(dso), sbuild_id, size);
 		dso__put(dso);
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index d729438b7d65..0f6b185f9589 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -354,7 +354,7 @@ int map__load(struct map *map)
 		if (dso__has_build_id(dso)) {
 			char sbuild_id[SBUILD_ID_SIZE];
 
-			build_id__sprintf(dso__bid(dso), sbuild_id);
+			build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id));
 			pr_debug("%s with build id %s not found", name, sbuild_id);
 		} else
 			pr_debug("Failed to open %s", name);
diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index ec8ac242fedb..5069fb61f48c 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -448,10 +448,10 @@ static int probe_cache__open(struct probe_cache *pcache, const char *target,
 	if (!target || !strcmp(target, DSO__NAME_KALLSYMS)) {
 		target = DSO__NAME_KALLSYMS;
 		is_kallsyms = true;
-		ret = sysfs__sprintf_build_id("/", sbuildid);
+		ret = sysfs__snprintf_build_id("/", sbuildid, sizeof(sbuildid));
 	} else {
 		nsinfo__mountns_enter(nsi, &nsc);
-		ret = filename__sprintf_build_id(target, sbuildid);
+		ret = filename__snprintf_build_id(target, sbuildid, sizeof(sbuildid));
 		nsinfo__mountns_exit(&nsc);
 	}
 
diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
index 00f2c6c5114d..6655c0bbe0d8 100644
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -780,14 +780,13 @@ static void set_sym_in_dict(PyObject *dict, struct addr_location *al,
 			    const char *sym_field, const char *symoff_field,
 			    const char *map_pgoff)
 {
-	char sbuild_id[SBUILD_ID_SIZE];
-
 	if (al->map) {
+		char sbuild_id[SBUILD_ID_SIZE];
 		struct dso *dso = map__dso(al->map);
 
 		pydict_set_item_string_decref(dict, dso_field,
 					      _PyUnicode_FromString(dso__name(dso)));
-		build_id__sprintf(dso__bid(dso), sbuild_id);
+		build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id));
 		pydict_set_item_string_decref(dict, dso_bid_field,
 			_PyUnicode_FromString(sbuild_id));
 		pydict_set_item_string_decref(dict, dso_map_start,
@@ -1238,7 +1237,7 @@ static int python_export_dso(struct db_export *dbe, struct dso *dso,
 	char sbuild_id[SBUILD_ID_SIZE];
 	PyObject *t;
 
-	build_id__sprintf(dso__bid(dso), sbuild_id);
+	build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id));
 
 	t = tuple_new(5);
 
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 8b30c6f16a9e..ea86a6253f04 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -2151,7 +2151,7 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map)
 			goto proc_kallsyms;
 	}
 
-	build_id__sprintf(dso__bid(dso), sbuild_id);
+	build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id));
 
 	/* Find kallsyms in build-id cache with kcore */
 	scnprintf(path, sizeof(path), "%s/%s/%s",
-- 
2.50.0.727.gbf7dc18ff4-goog
Re: [PATCH v5 03/23] perf build-id: Change sprintf functions to snprintf
Posted by Namhyung Kim 3 months, 1 week ago
On Fri, Jun 27, 2025 at 09:49:57PM -0700, Ian Rogers wrote:
> Pass in a size argument rather than implying all build id strings must
> be SBUILD_ID_SIZE.

I got these errors:

  CC      util/parse-event.o                                                   
util/probe-event.c: In function '__show_line_range':                            
util/probe-event.c:1093:17: error: implicit declaration of function 'build_id__sprintf'; did you mean 'build_id__snprintf'? [-Wimplicit-function-declaration]
 1093 |                 build_id__sprintf(&bid, sbuild_id);                     
      |                 ^~~~~~~~~~~~~~~~~                                       
      |                 build_id__snprintf    
  CC      util/parse-finder.o                                                   
util/probe-finder.c: In function 'find_probe_point_lazy':                       
util/probe-finder.c:863:25: error: implicit declaration of function 'build_id__sprintf'; did you mean 'build_id__snprintf'? [-Wimplicit-function-declaration]
  863 |                         build_id__sprintf(&bid, sbuild_id);             
      |                         ^~~~~~~~~~~~~~~~~                               
      |                         build_id__snprintf                              
make[4]: *** [/usr/local/google/home/namhyung/project/linux/tools/build/Makefile.build:86: util/probe-finder.o] Error 1
make[4]: *** Waiting for unfinished jobs....                                    
make[4]: *** [/usr/local/google/home/namhyung/project/linux/tools/build/Makefile.build:85: util/probe-event.o] Error 1
make[3]: *** [/usr/local/google/home/namhyung/project/linux/tools/build/Makefile.build:142: util] Error 2
make[2]: *** [Makefile.perf:797: perf-util-in.o] Error 2                        
make[2]: *** Waiting for unfinished jobs....                                    
make[1]: *** [Makefile.perf:289: sub-make] Error 2                              
make: *** [Makefile:76: all] Error 2

Thanks,
Namhyung

> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/builtin-buildid-cache.c            | 12 +++----
>  tools/perf/builtin-buildid-list.c             |  6 ++--
>  tools/perf/util/build-id.c                    | 33 ++++++++-----------
>  tools/perf/util/build-id.h                    |  6 ++--
>  tools/perf/util/disasm.c                      |  2 +-
>  tools/perf/util/dso.c                         |  4 +--
>  tools/perf/util/dsos.c                        |  2 +-
>  tools/perf/util/event.c                       |  2 +-
>  tools/perf/util/header.c                      |  2 +-
>  tools/perf/util/map.c                         |  2 +-
>  tools/perf/util/probe-file.c                  |  4 +--
>  .../scripting-engines/trace-event-python.c    |  7 ++--
>  tools/perf/util/symbol.c                      |  2 +-
>  13 files changed, 38 insertions(+), 46 deletions(-)
> 
> diff --git a/tools/perf/builtin-buildid-cache.c b/tools/perf/builtin-buildid-cache.c
> index b0511d16aeb6..3f7739b21148 100644
> --- a/tools/perf/builtin-buildid-cache.c
> +++ b/tools/perf/builtin-buildid-cache.c
> @@ -31,7 +31,7 @@
>  #include <linux/string.h>
>  #include <linux/err.h>
>  
> -static int build_id_cache__kcore_buildid(const char *proc_dir, char *sbuildid)
> +static int build_id_cache__kcore_buildid(const char *proc_dir, char *sbuildid, size_t sbuildid_size)
>  {
>  	char root_dir[PATH_MAX];
>  	char *p;
> @@ -42,7 +42,7 @@ static int build_id_cache__kcore_buildid(const char *proc_dir, char *sbuildid)
>  	if (!p)
>  		return -1;
>  	*p = '\0';
> -	return sysfs__sprintf_build_id(root_dir, sbuildid);
> +	return sysfs__snprintf_build_id(root_dir, sbuildid, sbuildid_size);
>  }
>  
>  static int build_id_cache__kcore_dir(char *dir, size_t sz)
> @@ -128,7 +128,7 @@ static int build_id_cache__add_kcore(const char *filename, bool force)
>  		return -1;
>  	*p = '\0';
>  
> -	if (build_id_cache__kcore_buildid(from_dir, sbuildid) < 0)
> +	if (build_id_cache__kcore_buildid(from_dir, sbuildid, sizeof(sbuildid)) < 0)
>  		return -1;
>  
>  	scnprintf(to_dir, sizeof(to_dir), "%s/%s/%s",
> @@ -187,7 +187,7 @@ static int build_id_cache__add_file(const char *filename, struct nsinfo *nsi)
>  		return -1;
>  	}
>  
> -	build_id__sprintf(&bid, sbuild_id);
> +	build_id__snprintf(&bid, sbuild_id, sizeof(sbuild_id));
>  	err = build_id_cache__add_s(sbuild_id, filename, nsi,
>  				    false, false);
>  	pr_debug("Adding %s %s: %s\n", sbuild_id, filename,
> @@ -211,7 +211,7 @@ static int build_id_cache__remove_file(const char *filename, struct nsinfo *nsi)
>  		return -1;
>  	}
>  
> -	build_id__sprintf(&bid, sbuild_id);
> +	build_id__snprintf(&bid, sbuild_id, sizeof(sbuild_id));
>  	err = build_id_cache__remove_s(sbuild_id);
>  	pr_debug("Removing %s %s: %s\n", sbuild_id, filename,
>  		 err ? "FAIL" : "Ok");
> @@ -317,7 +317,7 @@ static int build_id_cache__update_file(const char *filename, struct nsinfo *nsi)
>  	}
>  	err = 0;
>  
> -	build_id__sprintf(&bid, sbuild_id);
> +	build_id__snprintf(&bid, sbuild_id, sizeof(sbuild_id));
>  	if (build_id_cache__cached(sbuild_id))
>  		err = build_id_cache__remove_s(sbuild_id);
>  
> diff --git a/tools/perf/builtin-buildid-list.c b/tools/perf/builtin-buildid-list.c
> index 52dfacaff8e3..ba8ba0303920 100644
> --- a/tools/perf/builtin-buildid-list.c
> +++ b/tools/perf/builtin-buildid-list.c
> @@ -31,7 +31,7 @@ static int buildid__map_cb(struct map *map, void *arg __maybe_unused)
>  
>  	memset(bid_buf, 0, sizeof(bid_buf));
>  	if (dso__has_build_id(dso))
> -		build_id__sprintf(dso__bid_const(dso), bid_buf);
> +		build_id__snprintf(dso__bid_const(dso), bid_buf, sizeof(bid_buf));
>  	printf("%s %16" PRIx64 " %16" PRIx64, bid_buf, map__start(map), map__end(map));
>  	if (dso_long_name != NULL)
>  		printf(" %s", dso_long_name);
> @@ -57,7 +57,7 @@ static int sysfs__fprintf_build_id(FILE *fp)
>  	char sbuild_id[SBUILD_ID_SIZE];
>  	int ret;
>  
> -	ret = sysfs__sprintf_build_id("/", sbuild_id);
> +	ret = sysfs__snprintf_build_id("/", sbuild_id, sizeof(sbuild_id));
>  	if (ret != sizeof(sbuild_id))
>  		return ret < 0 ? ret : -EINVAL;
>  
> @@ -69,7 +69,7 @@ static int filename__fprintf_build_id(const char *name, FILE *fp)
>  	char sbuild_id[SBUILD_ID_SIZE];
>  	int ret;
>  
> -	ret = filename__sprintf_build_id(name, sbuild_id);
> +	ret = filename__snprintf_build_id(name, sbuild_id, sizeof(sbuild_id));
>  	if (ret != sizeof(sbuild_id))
>  		return ret < 0 ? ret : -EINVAL;
>  
> diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
> index 5bc2040bdd0d..aa35dceace90 100644
> --- a/tools/perf/util/build-id.c
> +++ b/tools/perf/util/build-id.c
> @@ -67,24 +67,17 @@ int build_id__mark_dso_hit(const struct perf_tool *tool __maybe_unused,
>  	return 0;
>  }
>  
> -int build_id__sprintf(const struct build_id *build_id, char *bf)
> +int build_id__snprintf(const struct build_id *build_id, char *bf, size_t bf_size)
>  {
> -	char *bid = bf;
> -	const u8 *raw = build_id->data;
> -	size_t i;
> -
> -	bf[0] = 0x0;
> +	size_t offs = 0;
>  
> -	for (i = 0; i < build_id->size; ++i) {
> -		sprintf(bid, "%02x", *raw);
> -		++raw;
> -		bid += 2;
> -	}
> +	for (size_t i = 0; i < build_id->size && offs < bf_size; ++i)
> +		offs += snprintf(bf + offs, bf_size - offs, "%02x", build_id->data[i]);
>  
> -	return (bid - bf) + 1;
> +	return offs;
>  }
>  
> -int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
> +int sysfs__snprintf_build_id(const char *root_dir, char *sbuild_id, size_t sbuild_id_size)
>  {
>  	char notes[PATH_MAX];
>  	struct build_id bid;
> @@ -99,10 +92,10 @@ int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
>  	if (ret < 0)
>  		return ret;
>  
> -	return build_id__sprintf(&bid, sbuild_id);
> +	return build_id__snprintf(&bid, sbuild_id, sbuild_id_size);
>  }
>  
> -int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
> +int filename__snprintf_build_id(const char *pathname, char *sbuild_id, size_t sbuild_id_size)
>  {
>  	struct build_id bid;
>  	int ret;
> @@ -111,7 +104,7 @@ int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
>  	if (ret < 0)
>  		return ret;
>  
> -	return build_id__sprintf(&bid, sbuild_id);
> +	return build_id__snprintf(&bid, sbuild_id, sbuild_id_size);
>  }
>  
>  /* asnprintf consolidates asprintf and snprintf */
> @@ -212,9 +205,9 @@ static bool build_id_cache__valid_id(char *sbuild_id)
>  		return false;
>  
>  	if (!strcmp(pathname, DSO__NAME_KALLSYMS))
> -		ret = sysfs__sprintf_build_id("/", real_sbuild_id);
> +		ret = sysfs__snprintf_build_id("/", real_sbuild_id, sizeof(real_sbuild_id));
>  	else if (pathname[0] == '/')
> -		ret = filename__sprintf_build_id(pathname, real_sbuild_id);
> +		ret = filename__snprintf_build_id(pathname, real_sbuild_id, sizeof(real_sbuild_id));
>  	else
>  		ret = -EINVAL;	/* Should we support other special DSO cache? */
>  	if (ret >= 0)
> @@ -243,7 +236,7 @@ char *__dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
>  	if (!dso__has_build_id(dso))
>  		return NULL;
>  
> -	build_id__sprintf(dso__bid_const(dso), sbuild_id);
> +	build_id__snprintf(dso__bid_const(dso), sbuild_id, sizeof(sbuild_id));
>  	linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
>  	if (!linkname)
>  		return NULL;
> @@ -769,7 +762,7 @@ static int build_id_cache__add_b(const struct build_id *bid,
>  {
>  	char sbuild_id[SBUILD_ID_SIZE];
>  
> -	build_id__sprintf(bid, sbuild_id);
> +	build_id__snprintf(bid, sbuild_id, sizeof(sbuild_id));
>  
>  	return __build_id_cache__add_s(sbuild_id, name, nsi, is_kallsyms,
>  				       is_vdso, proper_name, root_dir);
> diff --git a/tools/perf/util/build-id.h b/tools/perf/util/build-id.h
> index e3e0a446ff0c..47e621cebe1b 100644
> --- a/tools/perf/util/build-id.h
> +++ b/tools/perf/util/build-id.h
> @@ -21,10 +21,10 @@ struct feat_fd;
>  struct nsinfo;
>  
>  void build_id__init(struct build_id *bid, const u8 *data, size_t size);
> -int build_id__sprintf(const struct build_id *build_id, char *bf);
> +int build_id__snprintf(const struct build_id *build_id, char *bf, size_t bf_size);
>  bool build_id__is_defined(const struct build_id *bid);
> -int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id);
> -int filename__sprintf_build_id(const char *pathname, char *sbuild_id);
> +int sysfs__snprintf_build_id(const char *root_dir, char *sbuild_id, size_t sbuild_id_size);
> +int filename__snprintf_build_id(const char *pathname, char *sbuild_id, size_t sbuild_id_size);
>  char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf,
>  				    size_t size);
>  
> diff --git a/tools/perf/util/disasm.c b/tools/perf/util/disasm.c
> index 8f0eb56c6fc6..96e6a5d6eacc 100644
> --- a/tools/perf/util/disasm.c
> +++ b/tools/perf/util/disasm.c
> @@ -1218,7 +1218,7 @@ int symbol__strerror_disassemble(struct map_symbol *ms, int errnum, char *buf, s
>  		char *build_id_msg = NULL;
>  
>  		if (dso__has_build_id(dso)) {
> -			build_id__sprintf(dso__bid(dso), bf + 15);
> +			build_id__snprintf(dso__bid(dso), bf + 15, sizeof(bf) - 15);
>  			build_id_msg = bf;
>  		}
>  		scnprintf(buf, buflen,
> diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
> index 057fcf4225ac..97664610c37e 100644
> --- a/tools/perf/util/dso.c
> +++ b/tools/perf/util/dso.c
> @@ -217,7 +217,7 @@ int dso__read_binary_type_filename(const struct dso *dso,
>  			break;
>  		}
>  
> -		build_id__sprintf(dso__bid_const(dso), build_id_hex);
> +		build_id__snprintf(dso__bid_const(dso), build_id_hex, sizeof(build_id_hex));
>  		len = __symbol__join_symfs(filename, size, "/usr/lib/debug/.build-id/");
>  		snprintf(filename + len, size - len, "%.2s/%s.debug",
>  			 build_id_hex, build_id_hex + 2);
> @@ -1704,7 +1704,7 @@ static size_t dso__fprintf_buildid(struct dso *dso, FILE *fp)
>  {
>  	char sbuild_id[SBUILD_ID_SIZE];
>  
> -	build_id__sprintf(dso__bid(dso), sbuild_id);
> +	build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id));
>  	return fprintf(fp, "%s", sbuild_id);
>  }
>  
> diff --git a/tools/perf/util/dsos.c b/tools/perf/util/dsos.c
> index 4d213017d202..47538273915d 100644
> --- a/tools/perf/util/dsos.c
> +++ b/tools/perf/util/dsos.c
> @@ -373,7 +373,7 @@ static int dsos__fprintf_buildid_cb(struct dso *dso, void *data)
>  
>  	if (args->skip && args->skip(dso, args->parm))
>  		return 0;
> -	build_id__sprintf(dso__bid(dso), sbuild_id);
> +	build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id));
>  	args->ret += fprintf(args->fp, "%-40s %s\n", sbuild_id, dso__long_name(dso));
>  	return 0;
>  }
> diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
> index 14b0d3689137..fcf44149feb2 100644
> --- a/tools/perf/util/event.c
> +++ b/tools/perf/util/event.c
> @@ -334,7 +334,7 @@ size_t perf_event__fprintf_mmap2(union perf_event *event, FILE *fp)
>  
>  		build_id__init(&bid, event->mmap2.build_id,
>  			       event->mmap2.build_id_size);
> -		build_id__sprintf(&bid, sbuild_id);
> +		build_id__snprintf(&bid, sbuild_id, sizeof(sbuild_id));
>  
>  		return fprintf(fp, " %d/%d: [%#" PRI_lx64 "(%#" PRI_lx64 ") @ %#" PRI_lx64
>  				   " <%s>]: %c%c%c%c %s\n",
> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> index 2dea35237e81..44941b3adddd 100644
> --- a/tools/perf/util/header.c
> +++ b/tools/perf/util/header.c
> @@ -2291,7 +2291,7 @@ static int __event_process_build_id(struct perf_record_header_build_id *bev,
>  			free(m.name);
>  		}
>  
> -		build_id__sprintf(dso__bid(dso), sbuild_id);
> +		build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id));
>  		pr_debug("build id event received for %s: %s [%zu]\n",
>  			 dso__long_name(dso), sbuild_id, size);
>  		dso__put(dso);
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index d729438b7d65..0f6b185f9589 100644
> --- a/tools/perf/util/map.c
> +++ b/tools/perf/util/map.c
> @@ -354,7 +354,7 @@ int map__load(struct map *map)
>  		if (dso__has_build_id(dso)) {
>  			char sbuild_id[SBUILD_ID_SIZE];
>  
> -			build_id__sprintf(dso__bid(dso), sbuild_id);
> +			build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id));
>  			pr_debug("%s with build id %s not found", name, sbuild_id);
>  		} else
>  			pr_debug("Failed to open %s", name);
> diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
> index ec8ac242fedb..5069fb61f48c 100644
> --- a/tools/perf/util/probe-file.c
> +++ b/tools/perf/util/probe-file.c
> @@ -448,10 +448,10 @@ static int probe_cache__open(struct probe_cache *pcache, const char *target,
>  	if (!target || !strcmp(target, DSO__NAME_KALLSYMS)) {
>  		target = DSO__NAME_KALLSYMS;
>  		is_kallsyms = true;
> -		ret = sysfs__sprintf_build_id("/", sbuildid);
> +		ret = sysfs__snprintf_build_id("/", sbuildid, sizeof(sbuildid));
>  	} else {
>  		nsinfo__mountns_enter(nsi, &nsc);
> -		ret = filename__sprintf_build_id(target, sbuildid);
> +		ret = filename__snprintf_build_id(target, sbuildid, sizeof(sbuildid));
>  		nsinfo__mountns_exit(&nsc);
>  	}
>  
> diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
> index 00f2c6c5114d..6655c0bbe0d8 100644
> --- a/tools/perf/util/scripting-engines/trace-event-python.c
> +++ b/tools/perf/util/scripting-engines/trace-event-python.c
> @@ -780,14 +780,13 @@ static void set_sym_in_dict(PyObject *dict, struct addr_location *al,
>  			    const char *sym_field, const char *symoff_field,
>  			    const char *map_pgoff)
>  {
> -	char sbuild_id[SBUILD_ID_SIZE];
> -
>  	if (al->map) {
> +		char sbuild_id[SBUILD_ID_SIZE];
>  		struct dso *dso = map__dso(al->map);
>  
>  		pydict_set_item_string_decref(dict, dso_field,
>  					      _PyUnicode_FromString(dso__name(dso)));
> -		build_id__sprintf(dso__bid(dso), sbuild_id);
> +		build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id));
>  		pydict_set_item_string_decref(dict, dso_bid_field,
>  			_PyUnicode_FromString(sbuild_id));
>  		pydict_set_item_string_decref(dict, dso_map_start,
> @@ -1238,7 +1237,7 @@ static int python_export_dso(struct db_export *dbe, struct dso *dso,
>  	char sbuild_id[SBUILD_ID_SIZE];
>  	PyObject *t;
>  
> -	build_id__sprintf(dso__bid(dso), sbuild_id);
> +	build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id));
>  
>  	t = tuple_new(5);
>  
> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
> index 8b30c6f16a9e..ea86a6253f04 100644
> --- a/tools/perf/util/symbol.c
> +++ b/tools/perf/util/symbol.c
> @@ -2151,7 +2151,7 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map)
>  			goto proc_kallsyms;
>  	}
>  
> -	build_id__sprintf(dso__bid(dso), sbuild_id);
> +	build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id));
>  
>  	/* Find kallsyms in build-id cache with kcore */
>  	scnprintf(path, sizeof(path), "%s/%s/%s",
> -- 
> 2.50.0.727.gbf7dc18ff4-goog
>