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[Qemu-devel] [PULL 17/43] exec.c: Don't accidentally sign-extend 4-byte
From: |
Peter Maydell |
Subject: |
[Qemu-devel] [PULL 17/43] exec.c: Don't accidentally sign-extend 4-byte loads in subpage_read() |
Date: |
Fri, 15 Jun 2018 15:24:55 +0100 |
In subpage_read() we perform a load of the data into a local buffer
which we then access using ldub_p(), lduw_p(), ldl_p() or ldq_p()
depending on its size, storing the result into the uint64_t *data.
Since ldl_p() returns an 'int', this means that for the 4-byte
case we will sign-extend the data, whereas for 1 and 2 byte
reads we zero-extend it.
This ought not to matter since the caller will likely ignore values in
the high bytes of the data, but add a cast so that we're consistent.
Signed-off-by: Peter Maydell <address@hidden>
Reviewed-by: Richard Henderson <address@hidden>
Message-id: address@hidden
---
exec.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/exec.c b/exec.c
index 9cbba6adcd3..90b47cde7b1 100644
--- a/exec.c
+++ b/exec.c
@@ -2747,7 +2747,7 @@ static MemTxResult subpage_read(void *opaque, hwaddr
addr, uint64_t *data,
*data = lduw_p(buf);
return MEMTX_OK;
case 4:
- *data = ldl_p(buf);
+ *data = (uint32_t)ldl_p(buf);
return MEMTX_OK;
case 8:
*data = ldq_p(buf);
--
2.17.1
- [Qemu-devel] [PULL 00/43] target-arm queue, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 10/43] hw/arm/armv7m: Remove unused armv7m_init() function, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 11/43] arm: Don't crash if user tries to use a Cortex-M CPU without an NVIC, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 13/43] cpu-defs.h: Document CPUIOTLBEntry 'addr' field, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 08/43] hw/char/parallel: Convert away from old_mmio, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 07/43] hw/input/pckbd: Convert away from old_mmio, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 05/43] hw/block/pflash_cfi02: Convert away from old_mmio, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 17/43] exec.c: Don't accidentally sign-extend 4-byte loads in subpage_read(),
Peter Maydell <=
- [Qemu-devel] [PULL 16/43] bswap: Add new stn_*_p() and ldn_*_p() memory access functions, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 04/43] hw/m68k/mcf5206: Convert away from old_mmio, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 15/43] CODING_STYLE: Define our preferred form for multiline comments, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 09/43] stellaris: Stop using armv7m_init(), Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 23/43] target/arm: Implement SVE compress active elements, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 06/43] hw/watchdog/wdt_i6300esb: Convert away from old_mmio, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 12/43] hw/core/or-irq: Support more than 16 inputs to an OR gate, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 01/43] arm_gicv3_kvm: kvm_dist_get/put_priority: skip the registers banked by GICR_IPRIORITYR, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 14/43] cputlb: Pass cpu_transaction_failed() the correct physaddr, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 21/43] target/arm: Implement SVE Permute - Predicates Group, Peter Maydell, 2018/06/15