[PATCH bpf-next V2 2/2] selftests/bpf: test_progs avoid minus shell exit codes

[Jesper Dangaard Brouer <brouer@xxxxxxxxxx>]

There are a number of places in test_progs that use minus-1 as the argument
to exit(). This improper use as a process exit status is masked to be a
number between 0 and 255 as defined in man exit(3).

This patch use two different positive exit codes instead, to allow a shell
script to tell the two error cases apart.

Fixes: fd27b1835e70 ("selftests/bpf: Reset process and thread affinity after each test/sub-test")
Fixes: 811d7e375d08 ("bpf: selftests: Restore netns after each test")
Signed-off-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
---
 tools/testing/selftests/bpf/test_progs.c |   12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index e8f7cd5dbae4..50803b080593 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -12,7 +12,9 @@
 #include <string.h>
 #include <execinfo.h> /* backtrace */
 
-#define EXIT_NO_TEST 2
+#define EXIT_NO_TEST		2
+#define EXIT_ERR_NETNS		3
+#define EXIT_ERR_RESET_AFFINITY	4
 
 /* defined in test_progs.h */
 struct test_env env = {};
@@ -113,13 +115,13 @@ static void reset_affinity() {
 	if (err < 0) {
 		stdio_restore();
 		fprintf(stderr, "Failed to reset process affinity: %d!\n", err);
-		exit(-1);
+		exit(EXIT_ERR_RESET_AFFINITY);
 	}
 	err = pthread_setaffinity_np(pthread_self(), sizeof(cpuset), &cpuset);
 	if (err < 0) {
 		stdio_restore();
 		fprintf(stderr, "Failed to reset thread affinity: %d!\n", err);
-		exit(-1);
+		exit(EXIT_ERR_RESET_AFFINITY);
 	}
 }
 
@@ -128,7 +130,7 @@ static void save_netns(void)
 	env.saved_netns_fd = open("/proc/self/ns/net", O_RDONLY);
 	if (env.saved_netns_fd == -1) {
 		perror("open(/proc/self/ns/net)");
-		exit(-1);
+		exit(EXIT_ERR_NETNS);
 	}
 }
 
@@ -137,7 +139,7 @@ static void restore_netns(void)
 	if (setns(env.saved_netns_fd, CLONE_NEWNET) == -1) {
 		stdio_restore();
 		perror("setns(CLONE_NEWNS)");
-		exit(-1);
+		exit(EXIT_ERR_NETNS);
 	}
 }