Patch "selftests/bpf: no need to track next_match_pos in struct test_loader" has been added to the 6.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    selftests/bpf: no need to track next_match_pos in struct test_loader

to the 6.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     selftests-bpf-no-need-to-track-next_match_pos-in-str.patch
and it can be found in the queue-6.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 0b776675872f7464faf257370bef505dc5380c59
Author: Eduard Zingerman <eddyz87@xxxxxxxxx>
Date:   Mon Jul 22 16:38:40 2024 -0700

    selftests/bpf: no need to track next_match_pos in struct test_loader
    
    [ Upstream commit 4ef5d6af493558124b7a6c13cace58b938fe27d4 ]
    
    The call stack for validate_case() function looks as follows:
    - test_loader__run_subtests()
      - process_subtest()
        - run_subtest()
          - prepare_case(), which does 'tester->next_match_pos = 0';
          - validate_case(), which increments tester->next_match_pos.
    
    Hence, each subtest is run with next_match_pos freshly set to zero.
    Meaning that there is no need to persist this variable in the
    struct test_loader, use local variable instead.
    
    Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
    Signed-off-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
    Link: https://lore.kernel.org/r/20240722233844.1406874-7-eddyz87@xxxxxxxxx
    Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
    Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
    Stable-dep-of: f00bb757ed63 ("selftests/bpf: fix to avoid __msg tag de-duplication by clang")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/tools/testing/selftests/bpf/test_loader.c b/tools/testing/selftests/bpf/test_loader.c
index f14e10b0de96e..47508cf66e896 100644
--- a/tools/testing/selftests/bpf/test_loader.c
+++ b/tools/testing/selftests/bpf/test_loader.c
@@ -434,7 +434,6 @@ static void prepare_case(struct test_loader *tester,
 	bpf_program__set_flags(prog, prog_flags | spec->prog_flags);
 
 	tester->log_buf[0] = '\0';
-	tester->next_match_pos = 0;
 }
 
 static void emit_verifier_log(const char *log_buf, bool force)
@@ -450,25 +449,23 @@ static void validate_case(struct test_loader *tester,
 			  struct bpf_program *prog,
 			  int load_err)
 {
-	int i, j, err;
-	char *match;
 	regmatch_t reg_match[1];
+	const char *log = tester->log_buf;
+	int i, j, err;
 
 	for (i = 0; i < subspec->expect_msg_cnt; i++) {
 		struct expect_msg *msg = &subspec->expect_msgs[i];
+		const char *match = NULL;
 
 		if (msg->substr) {
-			match = strstr(tester->log_buf + tester->next_match_pos, msg->substr);
+			match = strstr(log, msg->substr);
 			if (match)
-				tester->next_match_pos = match - tester->log_buf + strlen(msg->substr);
+				log += strlen(msg->substr);
 		} else {
-			err = regexec(&msg->regex,
-				      tester->log_buf + tester->next_match_pos, 1, reg_match, 0);
+			err = regexec(&msg->regex, log, 1, reg_match, 0);
 			if (err == 0) {
-				match = tester->log_buf + tester->next_match_pos + reg_match[0].rm_so;
-				tester->next_match_pos += reg_match[0].rm_eo;
-			} else {
-				match = NULL;
+				match = log + reg_match[0].rm_so;
+				log += reg_match[0].rm_eo;
 			}
 		}
 
diff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h
index 0ba5a20b19ba8..8e997de596db0 100644
--- a/tools/testing/selftests/bpf/test_progs.h
+++ b/tools/testing/selftests/bpf/test_progs.h
@@ -438,7 +438,6 @@ typedef int (*pre_execution_cb)(struct bpf_object *obj);
 struct test_loader {
 	char *log_buf;
 	size_t log_buf_sz;
-	size_t next_match_pos;
 	pre_execution_cb pre_execution_cb;
 
 	struct bpf_object *obj;