selftests/bpf: Replace extract_build_id with read_build_id

Replacing extract_build_id with read_build_id that parses out
build id directly from elf without using readelf tool.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230331093157.1749137-4-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id.c b/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id.c
index 9ad09a6..b7ba5cd 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id.c
+++ b/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id.c
@@ -7,13 +7,12 @@ void test_stacktrace_build_id(void)
 
        int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd;
        struct test_stacktrace_build_id *skel;
-       int err, stack_trace_len;
+       int err, stack_trace_len, build_id_size;
        __u32 key, prev_key, val, duration = 0;
-       char buf[256];
-       int i, j;
+       char buf[BPF_BUILD_ID_SIZE];
        struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH];
        int build_id_matches = 0;
-       int retry = 1;
+       int i, retry = 1;
 
 retry:
        skel = test_stacktrace_build_id__open_and_load();
@@ -52,9 +51,10 @@ retry:
                  "err %d errno %d\n", err, errno))
                goto cleanup;
 
-       err = extract_build_id(buf, 256);
+       build_id_size = read_build_id("urandom_read", buf, sizeof(buf));
+       err = build_id_size < 0 ? build_id_size : 0;
 
-       if (CHECK(err, "get build_id with readelf",
+       if (CHECK(err, "read_build_id",
                  "err %d errno %d\n", err, errno))
                goto cleanup;
 
@@ -64,8 +64,6 @@ retry:
                goto cleanup;
 
        do {
-               char build_id[64];
-
                err = bpf_map_lookup_elem(stackmap_fd, &key, id_offs);
                if (CHECK(err, "lookup_elem from stackmap",
                          "err %d, errno %d\n", err, errno))
@@ -73,10 +71,7 @@ retry:
                for (i = 0; i < PERF_MAX_STACK_DEPTH; ++i)
                        if (id_offs[i].status == BPF_STACK_BUILD_ID_VALID &&
                            id_offs[i].offset != 0) {
-                               for (j = 0; j < 20; ++j)
-                                       sprintf(build_id + 2 * j, "%02x",
-                                               id_offs[i].build_id[j] & 0xff);
-                               if (strstr(buf, build_id) != NULL)
+                               if (memcmp(buf, id_offs[i].build_id, build_id_size) == 0)
                                        build_id_matches = 1;
                        }
                prev_key = key;

diff --git a/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c b/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c
index f4ea1a2..47558b0 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c
+++ b/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c
@@ -28,11 +28,10 @@ void test_stacktrace_build_id_nmi(void)
                .config = PERF_COUNT_HW_CPU_CYCLES,
        };
        __u32 key, prev_key, val, duration = 0;
-       char buf[256];
-       int i, j;
+       char buf[BPF_BUILD_ID_SIZE];
        struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH];
-       int build_id_matches = 0;
-       int retry = 1;
+       int build_id_matches = 0, build_id_size;
+       int i, retry = 1;
 
        attr.sample_freq = read_perf_max_sample_freq();
 
@@ -94,7 +93,8 @@ retry:
                  "err %d errno %d\n", err, errno))
                goto cleanup;
 
-       err = extract_build_id(buf, 256);
+       build_id_size = read_build_id("urandom_read", buf, sizeof(buf));
+       err = build_id_size < 0 ? build_id_size : 0;
 
        if (CHECK(err, "get build_id with readelf",
                  "err %d errno %d\n", err, errno))
@@ -106,8 +106,6 @@ retry:
                goto cleanup;
 
        do {
-               char build_id[64];
-
                err = bpf_map__lookup_elem(skel->maps.stackmap, &key, sizeof(key),
                                           id_offs, sizeof(id_offs), 0);
                if (CHECK(err, "lookup_elem from stackmap",
@@ -116,10 +114,7 @@ retry:
                for (i = 0; i < PERF_MAX_STACK_DEPTH; ++i)
                        if (id_offs[i].status == BPF_STACK_BUILD_ID_VALID &&
                            id_offs[i].offset != 0) {
-                               for (j = 0; j < 20; ++j)
-                                       sprintf(build_id + 2 * j, "%02x",
-                                               id_offs[i].build_id[j] & 0xff);
-                               if (strstr(buf, build_id) != NULL)
+                               if (memcmp(buf, id_offs[i].build_id, build_id_size) == 0)
                                        build_id_matches = 1;
                        }
                prev_key = key;

diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index d903e6a..ea82921 100644 (file)
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -629,31 +629,6 @@ out:
        return err;
 }
 
-int extract_build_id(char *build_id, size_t size)
-{
-       FILE *fp;
-       char *line = NULL;
-       size_t len = 0;
-
-       fp = popen("readelf -n ./urandom_read | grep 'Build ID'", "r");
-       if (fp == NULL)
-               return -1;
-
-       if (getline(&line, &len, fp) == -1)
-               goto err;
-       pclose(fp);
-
-       if (len > size)
-               len = size;
-       memcpy(build_id, line, len);
-       build_id[len] = '\0';
-       free(line);
-       return 0;
-err:
-       pclose(fp);
-       return -1;
-}
-
 static int finit_module(int fd, const char *param_values, int flags)
 {
        return syscall(__NR_finit_module, fd, param_values, flags);

diff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h
index 4b06b83..10ba432 100644 (file)
--- a/tools/testing/selftests/bpf/test_progs.h
+++ b/tools/testing/selftests/bpf/test_progs.h
@@ -405,7 +405,6 @@ static inline void *u64_to_ptr(__u64 ptr)
 int bpf_find_map(const char *test, struct bpf_object *obj, const char *name);
 int compare_map_keys(int map1_fd, int map2_fd);
 int compare_stack_ips(int smap_fd, int amap_fd, int stack_trace_len);
-int extract_build_id(char *build_id, size_t size);
 int kern_sync_rcu(void);
 int trigger_module_test_read(int read_sz);
 int trigger_module_test_write(int write_sz);