diff options
author | Song Liu <songliubraving@fb.com> | 2021-10-23 02:48:14 +0300 |
---|---|---|
committer | Andrii Nakryiko <andrii@kernel.org> | 2021-10-26 07:43:05 +0300 |
commit | 20d1b54a52bd9a1d5d23a45dab75993ce2f1d617 (patch) | |
tree | c9e04e910758f076c94c445121a09df0da51c3cb /tools | |
parent | b4e87072762d063f9c20ba0ab2120e1910fa379f (diff) | |
download | linux-20d1b54a52bd9a1d5d23a45dab75993ce2f1d617.tar.xz |
selftests/bpf: Guess function end for test_get_branch_snapshot
Function in modules could appear in /proc/kallsyms in random order.
ffffffffa02608a0 t bpf_testmod_loop_test
ffffffffa02600c0 t __traceiter_bpf_testmod_test_writable_bare
ffffffffa0263b60 d __tracepoint_bpf_testmod_test_write_bare
ffffffffa02608c0 T bpf_testmod_test_read
ffffffffa0260d08 t __SCT__tp_func_bpf_testmod_test_writable_bare
ffffffffa0263300 d __SCK__tp_func_bpf_testmod_test_read
ffffffffa0260680 T bpf_testmod_test_write
ffffffffa0260860 t bpf_testmod_test_mod_kfunc
Therefore, we cannot reliably use kallsyms_find_next() to find the end of
a function. Replace it with a simple guess (start + 128). This is good
enough for this test.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211022234814.318457-1-songliubraving@fb.com
Diffstat (limited to 'tools')
-rw-r--r-- | tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c | 7 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/trace_helpers.c | 36 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/trace_helpers.h | 5 |
3 files changed, 4 insertions, 44 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c index 81402e443984..3948da12a528 100644 --- a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c +++ b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c @@ -97,9 +97,10 @@ void serial_test_get_branch_snapshot(void) if (!ASSERT_OK(err, "kallsyms_find")) goto cleanup; - err = kallsyms_find_next("bpf_testmod_loop_test", &skel->bss->address_high); - if (!ASSERT_OK(err, "kallsyms_find_next")) - goto cleanup; + /* Just a guess for the end of this function, as module functions + * in /proc/kallsyms could come in any order. + */ + skel->bss->address_high = skel->bss->address_low + 128; err = get_branch_snapshot__attach(skel); if (!ASSERT_OK(err, "get_branch_snapshot__attach")) diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index 5100a169b72b..7b7f918eda77 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -118,42 +118,6 @@ out: return err; } -/* find the address of the next symbol of the same type, this can be used - * to determine the end of a function. - */ -int kallsyms_find_next(const char *sym, unsigned long long *addr) -{ - char type, found_type, name[500]; - unsigned long long value; - bool found = false; - int err = 0; - FILE *f; - - f = fopen("/proc/kallsyms", "r"); - if (!f) - return -EINVAL; - - while (fscanf(f, "%llx %c %499s%*[^\n]\n", &value, &type, name) > 0) { - /* Different types of symbols in kernel modules are mixed - * in /proc/kallsyms. Only return the next matching type. - * Use tolower() for type so that 'T' matches 't'. - */ - if (found && found_type == tolower(type)) { - *addr = value; - goto out; - } - if (strcmp(name, sym) == 0) { - found = true; - found_type = tolower(type); - } - } - err = -ENOENT; - -out: - fclose(f); - return err; -} - void read_trace_pipe(void) { int trace_fd; diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h index bc8ed86105d9..d907b445524d 100644 --- a/tools/testing/selftests/bpf/trace_helpers.h +++ b/tools/testing/selftests/bpf/trace_helpers.h @@ -16,11 +16,6 @@ long ksym_get_addr(const char *name); /* open kallsyms and find addresses on the fly, faster than load + search. */ int kallsyms_find(const char *sym, unsigned long long *addr); -/* find the address of the next symbol, this can be used to determine the - * end of a function - */ -int kallsyms_find_next(const char *sym, unsigned long long *addr); - void read_trace_pipe(void); ssize_t get_uprobe_offset(const void *addr, ssize_t base); |