From af0efa050caa66e8f304c42c94c76cb6c480cb7e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>
Date: Tue, 6 Jul 2021 14:23:55 +0200
Subject: [PATCH] libbpf: Restore errno return for functions that were already
returning it
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The update to streamline libbpf error reporting intended to change all
functions to return the errno as a negative return value if
LIBBPF_STRICT_DIRECT_ERRS is set. However, if the flag is *not* set, the
return value changes for the two functions that were already returning a
negative errno unconditionally: bpf_link__unpin() and perf_buffer__poll().
This is a user-visible API change that breaks applications; so let's revert
these two functions back to unconditionally returning a negative errno
value.
Fixes: e9fc3ce99b34 ("libbpf: Streamline error reporting for high-level APIs")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210706122355.236082-1-toke@redhat.com
---
tools/lib/bpf/libbpf.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 1e04ce724240f..6f5e2757bb3cf 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -10136,7 +10136,7 @@ int bpf_link__unpin(struct bpf_link *link)
err = unlink(link->pin_path);
if (err != 0)
- return libbpf_err_errno(err);
+ return -errno;
pr_debug("link fd=%d: unpinned from %s\n", link->fd, link->pin_path);
zfree(&link->pin_path);
@@ -11197,7 +11197,7 @@ int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms)
cnt = epoll_wait(pb->epoll_fd, pb->events, pb->cpu_cnt, timeout_ms);
if (cnt < 0)
- return libbpf_err_errno(cnt);
+ return -errno;
for (i = 0; i < cnt; i++) {
struct perf_cpu_buf *cpu_buf = pb->events[i].data.ptr;
--
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