From eee01f35e1700da04b6ba1dc2e0d5d34cf52b4a1 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Mon, 2 Mar 2020 16:01:19 -0700 Subject: [PATCH 1276/2944] io_uring: Ensure mask is initialized in io_arm_poll_handler to #28170604 commit 8755d97a09fed0de206772bcad1838301293c4d8 upstream Clang warns: fs/io_uring.c:4178:6: warning: variable 'mask' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] if (def->pollin) ^~~~~~~~~~~ fs/io_uring.c:4182:2: note: uninitialized use occurs here mask |= POLLERR | POLLPRI; ^~~~ fs/io_uring.c:4178:2: note: remove the 'if' if its condition is always true if (def->pollin) ^~~~~~~~~~~~~~~~ fs/io_uring.c:4154:15: note: initialize the variable 'mask' to silence this warning __poll_t mask, ret; ^ = 0 1 warning generated. io_op_defs has many definitions where pollin is not set so mask indeed might be uninitialized. Initialize it to zero and change the next assignment to |=, in case further masks are added in the future to avoid missing changing the assignment then. Fixes: d7718a9d25a6 ("io_uring: use poll driven retry for files that support it") Link: https://github.com/ClangBuiltLinux/linux/issues/916 Signed-off-by: Nathan Chancellor Signed-off-by: Jens Axboe Acked-by: Joseph Qi Signed-off-by: Xiaoguang Wang --- fs/io_uring.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index ae0da59..b8a4d7d 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3747,8 +3747,9 @@ static bool io_arm_poll_handler(struct io_kiocb *req) req->apoll = apoll; INIT_HLIST_NODE(&req->hash_node); + mask = 0; if (def->pollin) - mask = POLLIN | POLLRDNORM; + mask |= POLLIN | POLLRDNORM; if (def->pollout) mask |= POLLOUT | POLLWRNORM; mask |= POLLERR | POLLPRI; -- 1.8.3.1