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Tsirkin" To: qemu-devel@nongnu.org Subject: [PULL 16/52] chardev/char-socket: tcp_chr_sync_read: don't clobber errno Message-ID: <20220106131534.423671-17-mst@redhat.com> References: <20220106131534.423671-1-mst@redhat.com> MIME-Version: 1.0 In-Reply-To: <20220106131534.423671-1-mst@redhat.com> X-Mailer: git-send-email 2.27.0.106.g8ac3dc51b1 X-Mutt-Fcc: =sent Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mst@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=mst@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.372, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Roman Kagan , Peter Maydell , Paolo Bonzini , =?utf-8?Q?Marc-Andr=C3=A9?= Lureau Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Roman Kagan After the return from tcp_chr_recv, tcp_chr_sync_read calls into a function which eventually makes a system call and may clobber errno. Make a copy of errno right after tcp_chr_recv and restore the errno on return from tcp_chr_sync_read. Signed-off-by: Roman Kagan Message-Id: <20211111153354.18807-4-rvkagan@yandex-team.ru> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Reviewed-by: Marc-André Lureau --- chardev/char-socket.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/chardev/char-socket.c b/chardev/char-socket.c index 3ddd98ed49..fab2d791d4 100644 --- a/chardev/char-socket.c +++ b/chardev/char-socket.c @@ -525,6 +525,7 @@ static int tcp_chr_sync_read(Chardev *chr, const uint8_t *buf, int len) { SocketChardev *s = SOCKET_CHARDEV(chr); int size; + int saved_errno; if (s->state != TCP_CHARDEV_STATE_CONNECTED) { return 0; @@ -532,6 +533,7 @@ static int tcp_chr_sync_read(Chardev *chr, const uint8_t *buf, int len) qio_channel_set_blocking(s->ioc, true, NULL); size = tcp_chr_recv(chr, (void *) buf, len); + saved_errno = errno; if (s->state != TCP_CHARDEV_STATE_DISCONNECTED) { qio_channel_set_blocking(s->ioc, false, NULL); } @@ -540,6 +542,7 @@ static int tcp_chr_sync_read(Chardev *chr, const uint8_t *buf, int len) tcp_chr_disconnect(chr); } + errno = saved_errno; return size; } -- MST