From: "Cédric Le Goater" <clg@kaod.org>
To: qemu-devel@nongnu.org
Cc: "Cédric Le Goater" <clg@redhat.com>,
"Stefan Hajnoczi" <stefanha@redhat.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Daniel P . Berrangé" <berrange@redhat.com>
Subject: [PATCH for-8.0 v2 1/3] async: Suppress GCC13 false positive in aio_bh_poll()
Date: Tue, 21 Mar 2023 17:16:07 +0100 [thread overview]
Message-ID: <20230321161609.716474-2-clg@kaod.org> (raw)
In-Reply-To: <20230321161609.716474-1-clg@kaod.org>
From: Cédric Le Goater <clg@redhat.com>
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 <stefanha@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
util/async.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/util/async.c b/util/async.c
index 21016a1ac7..de9b431236 100644
--- a/util/async.c
+++ b/util/async.c
@@ -164,7 +164,20 @@ 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 "-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;
--
2.39.2
next prev parent reply other threads:[~2023-03-21 16:17 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-21 16:16 [PATCH for-8.0 v2 0/3] Fixes for GCC13 Cédric Le Goater
2023-03-21 16:16 ` Cédric Le Goater [this message]
2023-03-22 7:11 ` [PATCH for-8.0 v2 1/3] async: Suppress GCC13 false positive in aio_bh_poll() Thomas Huth
2023-03-22 8:47 ` Philippe Mathieu-Daudé
2023-03-22 10:21 ` Cédric Le Goater
2023-03-22 13:27 ` Stefan Hajnoczi
2023-03-22 14:42 ` Philippe Mathieu-Daudé
2023-04-18 7:31 ` Marc-André Lureau
2023-04-20 18:43 ` Daniel Henrique Barboza
2023-03-21 16:16 ` [PATCH for-8.0 v2 2/3] target/s390x: Fix float_comp_to_cc() prototype Cédric Le Goater
2023-03-22 3:54 ` Richard Henderson
2023-03-22 6:52 ` Thomas Huth
2023-03-21 16:16 ` [PATCH for-8.0 v2 3/3] target/ppc: Fix helper_pminsn() prototype Cédric Le Goater
2023-03-22 3:54 ` Richard Henderson
2023-03-22 6:55 ` Thomas Huth
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