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authorAlviro Iskandar Setiawan <alviro.iskandar@gmail.com>2022-02-07 17:05:33 +0300
committerJens Axboe <axboe@kernel.dk>2022-02-07 18:38:07 +0300
commit0d7c1153d9291197c1dc473cfaade77acb874b4b (patch)
tree029646ee8632b7ee9fa3b9ddd847826e74ef44fb /fs
parentf6133fbd373811066c8441737e65f384c8f31974 (diff)
downloadlinux-0d7c1153d9291197c1dc473cfaade77acb874b4b.tar.xz
io_uring: Clean up a false-positive warning from GCC 9.3.0
In io_recv(), if import_single_range() fails, the @flags variable is uninitialized, then it will goto out_free. After the goto, the compiler doesn't know that (ret < min_ret) is always true, so it thinks the "if ((flags & MSG_WAITALL) ..." path could be taken. The complaint comes from gcc-9 (Debian 9.3.0-22) 9.3.0: ``` fs/io_uring.c:5238 io_recvfrom() error: uninitialized symbol 'flags' ``` Fix this by bypassing the @ret and @flags check when import_single_range() fails. Reasons: 1. import_single_range() only returns -EFAULT when it fails. 2. At that point, @flags is uninitialized and shouldn't be read. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reported-by: "Chen, Rong A" <rong.a.chen@intel.com> Link: https://lore.gnuweeb.org/timl/d33bb5a9-8173-f65b-f653-51fc0681c6d6@intel.com/ Cc: Pavel Begunkov <asml.silence@gmail.com> Suggested-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Fixes: 7297ce3d59449de49d3c9e1f64ae25488750a1fc ("io_uring: improve send/recv error handling") Signed-off-by: Alviro Iskandar Setiawan <alviro.iskandar@gmail.com> Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Link: https://lore.kernel.org/r/20220207140533.565411-1-ammarfaizi2@gnuweeb.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs')
-rw-r--r--fs/io_uring.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 2e04f718319d..3445c4da0153 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -5228,7 +5228,6 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags)
min_ret = iov_iter_count(&msg.msg_iter);
ret = sock_recvmsg(sock, &msg, flags);
-out_free:
if (ret < min_ret) {
if (ret == -EAGAIN && force_nonblock)
return -EAGAIN;
@@ -5236,9 +5235,9 @@ out_free:
ret = -EINTR;
req_set_fail(req);
} else if ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
+out_free:
req_set_fail(req);
}
-
__io_req_complete(req, issue_flags, ret, io_put_kbuf(req));
return 0;
}