From d66ba6dc1cce914673bd8a89fca30a7715ea70d1 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Date: Thu, 20 Apr 2023 22:29:39 +0200 Subject: [PATCH] async: Suppress GCC13 false positive in aio_bh_poll() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit GCC13 reports an error : ../util/async.c: In function ‘aio_bh_poll’: include/qemu/queue.h:303:22: error: storing the address of local variable ‘slice’ in ‘*ctx.bh_slice_list.sqh_last’ [-Werror=dangling-pointer=] 303 | (head)->sqh_last = &(elm)->field.sqe_next; \ | ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~ ../util/async.c:169:5: note: in expansion of macro ‘QSIMPLEQ_INSERT_TAIL’ 169 | QSIMPLEQ_INSERT_TAIL(&ctx->bh_slice_list, &slice, next); | ^~~~~~~~~~~~~~~~~~~~ ../util/async.c:161:17: note: ‘slice’ declared here 161 | BHListSlice slice; | ^~~~~ ../util/async.c:161:17: note: ‘ctx’ declared here But the local variable 'slice' is removed from the global context list in following loop of the same routine. Add a pragma to silent GCC. Cc: Stefan Hajnoczi Cc: Paolo Bonzini Cc: Daniel P. Berrangé Signed-off-by: Cédric Le Goater Reviewed-by: Daniel Henrique Barboza Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Stefan Hajnoczi Reviewed-by: Thomas Huth Tested-by: Daniel Henrique Barboza Message-Id: <20230420202939.1982044-1-clg@kaod.org> Signed-off-by: Paolo Bonzini --- util/async.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/util/async.c b/util/async.c index 21016a1ac7..856e1a8a33 100644 --- a/util/async.c +++ b/util/async.c @@ -164,7 +164,21 @@ int aio_bh_poll(AioContext *ctx) /* Synchronizes with QSLIST_INSERT_HEAD_ATOMIC in aio_bh_enqueue(). */ QSLIST_MOVE_ATOMIC(&slice.bh_list, &ctx->bh_list); + + /* + * GCC13 [-Werror=dangling-pointer=] complains that the local variable + * 'slice' is being stored in the global 'ctx->bh_slice_list' but the + * list is emptied before this function returns. + */ +#if !defined(__clang__) +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wpragmas" +#pragma GCC diagnostic ignored "-Wdangling-pointer=" +#endif QSIMPLEQ_INSERT_TAIL(&ctx->bh_slice_list, &slice, next); +#if !defined(__clang__) +#pragma GCC diagnostic pop +#endif while ((s = QSIMPLEQ_FIRST(&ctx->bh_slice_list))) { QEMUBH *bh;