[bpf-next PATCH 04/10] bpf: selftests, print error in test_sockmap error cases

[John Fastabend]

Its helpful to know the error value if an error occurs.

Signed-off-by: John Fastabend <john.fastab...@gmail.com>
---
 tools/testing/selftests/bpf/test_sockmap.c |   25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_sockmap.c 
b/tools/testing/selftests/bpf/test_sockmap.c
index a0884f8..a81ed5d 100644
--- a/tools/testing/selftests/bpf/test_sockmap.c
+++ b/tools/testing/selftests/bpf/test_sockmap.c
@@ -341,14 +341,18 @@ static int msg_loop_sendpage(int fd, int iov_length, int 
cnt,
 
        clock_gettime(CLOCK_MONOTONIC, &s->start);
        for (i = 0; i < cnt; i++) {
-               int sent = sendfile(fd, fp, NULL, iov_length);
+               int sent;
+
+               errno = 0;
+               sent = sendfile(fd, fp, NULL, iov_length);
 
                if (!drop && sent < 0) {
-                       perror("send loop error");
+                       perror("sendpage loop error");
                        fclose(file);
                        return sent;
                } else if (drop && sent >= 0) {
-                       printf("sendpage loop error expected: %i\n", sent);
+                       printf("sendpage loop error expected: %i errno %i\n",
+                              sent, errno);
                        fclose(file);
                        return -EIO;
                }
@@ -460,13 +464,18 @@ static int msg_loop(int fd, int iov_count, int 
iov_length, int cnt,
        if (tx) {
                clock_gettime(CLOCK_MONOTONIC, &s->start);
                for (i = 0; i < cnt; i++) {
-                       int sent = sendmsg(fd, &msg, flags);
+                       int sent;
+
+                       errno = 0;
+                       sent = sendmsg(fd, &msg, flags);
 
                        if (!drop && sent < 0) {
-                               perror("send loop error");
+                               perror("sendmsg loop error");
                                goto out_errno;
                        } else if (drop && sent >= 0) {
-                               printf("send loop error expected: %i\n", sent);
+                               fprintf(stderr,
+                                       "sendmsg loop error expected: %i errno 
%i\n",
+                                       sent, errno);
                                errno = -EIO;
                                goto out_errno;
                        }
@@ -690,14 +699,14 @@ static int sendmsg_test(struct sockmap_options *opt)
        if (WIFEXITED(rx_status)) {
                err = WEXITSTATUS(rx_status);
                if (err) {
-                       fprintf(stderr, "rx thread exited with err %d. ", err);
+                       fprintf(stderr, "rx thread exited with err %d.\n", err);
                        goto out;
                }
        }
        if (WIFEXITED(tx_status)) {
                err = WEXITSTATUS(tx_status);
                if (err)
-                       fprintf(stderr, "tx thread exited with err %d. ", err);
+                       fprintf(stderr, "tx thread exited with err %d.\n", err);
        }
 out:
        return err;