Commit b7b1e9dd authored Jul 26, 2017 by Philippe Mathieu-Daudé Committed by Michael Tokarev Jul 31, 2017

ivshmem: fix incorrect error handling in ivshmem_recv_msg()



Screwed up in commit 3a55fc0f, v2.6.0.

If qemu_chr_fe_read_all() returns -EINTR the do {} statement continues and the
n accumulator used to complete reads upto sizeof(msg) is decremented by 4 (the
value of EINTR on Linux).
To avoid that, use simpler if() statements and continue if EINTR occured.

hw/misc/ivshmem.c:650:14: warning: Loss of sign in implicit conversion
    } while (n < sizeof(msg));
             ^

Reported-by: Clang Static Analyzer
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

parent 2a4e2e49

hw/misc/ivshmem.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -642,7 +642,10 @@ static int64_t ivshmem_recv_msg(IVShmemState s, int pfd, Error **errp)
		do {
		ret = qemu_chr_fe_read_all(&s->server_chr, (uint8_t *)&msg + n,
		sizeof(msg) - n);
		if (ret < 0 && ret != -EINTR) {
		if (ret < 0) {
		if (ret == -EINTR) {
		continue;
		}
		error_setg_errno(errp, -ret, "read from server failed");
		return INT64_MIN;
		}