[PATCH 5.5 170/367] selftests/bpf: Fix test_attach_probe

Greg Kroah-Hartman
2020-02-10T13:02:24Z

From: Alexei Starovoitov <ast@kernel.org>

commit 580205dd4fe800b1e95be8b6df9e2991f975a8ad upstream.

Fix two issues in test_attach_probe:

1. it was not able to parse /proc/self/maps beyond the first line,
since %s means parse string until white space.
2. offset has to be accounted for otherwise uprobed address is incorrect.

Fixes: 1e8611bbdfc9 ("selftests/bpf: add kprobe/uprobe selftests")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191219020442.1922617-1-ast@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
tools/testing/selftests/bpf/prog_tests/attach_probe.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

--- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c
+++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c
@@ -20,7 +20,7 @@ extern char NAME##_data[]; \
extern int NAME##_size;

ssize_t get_base_addr() {
- size_t start;
+ size_t start, offset;
char buf[256];
FILE *f;

@@ -28,10 +28,11 @@ ssize_t get_base_addr() {
if (!f)
return -errno;

- while (fscanf(f, "%zx-%*x %s %*s\n", &start, buf) == 2) {
+ while (fscanf(f, "%zx-%*x %s %zx %*[^\n]\n",
+ &start, buf, &offset) == 3) {
if (strcmp(buf, "r-xp") == 0) {
fclose(f);
- return start;
+ return start - offset;
}
}