From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49554) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zn97n-0000Q1-8j for qemu-devel@nongnu.org; Fri, 16 Oct 2015 13:49:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zn97m-0000wf-AM for qemu-devel@nongnu.org; Fri, 16 Oct 2015 13:49:03 -0400 Received: from mnementh.archaic.org.uk ([2001:8b0:1d0::1]:35161) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zn97m-0000wF-3h for qemu-devel@nongnu.org; Fri, 16 Oct 2015 13:49:02 -0400 From: Peter Maydell Date: Fri, 16 Oct 2015 18:48:59 +0100 Message-Id: <1445017739-14876-1-git-send-email-peter.maydell@linaro.org> Subject: [Qemu-devel] [PATCH] hw/ide/ahci.c: Fix shift left into sign bit List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: John Snow , qemu-block@nongnu.org, patches@linaro.org Avoid undefined behaviour from shifting left into the sign bit: hw/ide/ahci.c:551:36: runtime error: left shift of 255 by 24 places cannot be represented in type 'int' (Unfortunately C's promotion rules mean that in the expression "some_uint8_t_variable << 24" the LHS gets promoted to signed int before shifting.) Signed-off-by: Peter Maydell --- clang's undefined sanitizer produces a lot of copies of this warning during 'make check'... hw/ide/ahci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c index 796be15..21f76ed 100644 --- a/hw/ide/ahci.c +++ b/hw/ide/ahci.c @@ -548,7 +548,7 @@ static void ahci_init_d2h(AHCIDevice *ad) ad->init_d2h_sent = true; /* We're emulating receiving the first Reg H2D Fis from the device; * Update the SIG register, but otherwise proceed as normal. */ - pr->sig = (ide_state->hcyl << 24) | + pr->sig = ((uint32_t)ide_state->hcyl << 24) | (ide_state->lcyl << 16) | (ide_state->sector << 8) | (ide_state->nsector & 0xFF); -- 1.9.1