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[Qemu-block] [PATCH] hw/ide/ahci.c: Fix shift left into sign bit
From: |
Peter Maydell |
Subject: |
[Qemu-block] [PATCH] hw/ide/ahci.c: Fix shift left into sign bit |
Date: |
Fri, 16 Oct 2015 18:48:59 +0100 |
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 <address@hidden>
---
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
- [Qemu-block] [PATCH] hw/ide/ahci.c: Fix shift left into sign bit,
Peter Maydell <=