[PATCH v3] io_uring: fix incorrect __kernel_rwf_t cast

From: Vasily Averin
Date: Thu May 19 2022 - 10:30:57 EST


Currently 'make C=1 fs/io_uring.o' generates sparse warning:

CHECK fs/io_uring.c
fs/io_uring.c: note: in included file (through
include/trace/trace_events.h, include/trace/define_trace.h, i
nclude/trace/events/io_uring.h):
./include/trace/events/io_uring.h:488:1:
warning: incorrect type in assignment (different base types)
expected unsigned int [usertype] op_flags
got restricted __kernel_rwf_t const [usertype] rw_flags

This happen on cast of sqe->rw_flags which is defined as __kernel_rwf_t,
this type is bitwise and requires __force attribute for any casts.
However rw_flags is a member of the union, and its access can be safely
replaced by using of its neighbours, so let's use poll32_events to fix
the sparse warning.

Signed-off-by: Vasily Averin <vvs@xxxxxxxxxx>
---
v3:
1) fix only hunk in TRACE_EVENT(io_uring_req_failed),
rest ones was fixed by Christoph Hellwig already.
2) updated patch description

v2: updated according to comments by Christoph Hellwig

---
include/trace/events/io_uring.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/trace/events/io_uring.h b/include/trace/events/io_uring.h
index 80d2588a090c..6ba87a290a24 100644
--- a/include/trace/events/io_uring.h
+++ b/include/trace/events/io_uring.h
@@ -520,7 +520,7 @@ TRACE_EVENT(io_uring_req_failed,
__entry->off = sqe->off;
__entry->addr = sqe->addr;
__entry->len = sqe->len;
- __entry->op_flags = sqe->rw_flags;
+ __entry->op_flags = sqe->poll32_events;
__entry->buf_index = sqe->buf_index;
__entry->personality = sqe->personality;
__entry->file_index = sqe->file_index;
--
2.31.1