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[Qemu-devel] [PULL 41/41] memory: don't sign-extend 32-bit writes
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 41/41] memory: don't sign-extend 32-bit writes |
Date: |
Fri, 27 Jan 2017 14:45:49 +0100 |
From: Ladi Prosek <address@hidden>
ldl_p has a signed return type so assigning it to uint64_t implicitly
sign-extends the value. This results in devices with min_access_size = 8
seeing unexpected values passed to their write handlers.
Example: guest performs a 32-bit write of 0x80000000 to an mmio region
and the handler receives 0xFFFFFFFF80000000 in its value argument.
Signed-off-by: Ladi Prosek <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
exec.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/exec.c b/exec.c
index f2bed92..b05c5d2 100644
--- a/exec.c
+++ b/exec.c
@@ -2630,7 +2630,7 @@ static MemTxResult
address_space_write_continue(AddressSpace *as, hwaddr addr,
break;
case 4:
/* 32 bit write access */
- val = ldl_p(buf);
+ val = (uint32_t)ldl_p(buf);
result |= memory_region_dispatch_write(mr, addr1, val, 4,
attrs);
break;
--
1.8.3.1
- [Qemu-devel] [PULL 29/41] char: introduce generic qemu_chr_get_kind(), (continued)
- [Qemu-devel] [PULL 29/41] char: introduce generic qemu_chr_get_kind(), Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 32/41] bt: use qemu_chr_alloc(), Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 27/41] char: move callbacks in CharDriver, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 35/41] spice-char: improve error reporting, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 37/41] gtk: overwrite the console.c char driver, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 34/41] char: rename TCPChardev and NetChardev, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 38/41] baum: use a common prefix for chr callbacks, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 36/41] char: use error_report(), Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 31/41] char: allocate CharDriverState as a single object, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 39/41] vc: use a common prefix for chr callbacks, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 41/41] memory: don't sign-extend 32-bit writes,
Paolo Bonzini <=
- [Qemu-devel] [PULL 33/41] char: rename CharDriverState Chardev, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 40/41] chardev: qom-ify, Paolo Bonzini, 2017/01/27
- Re: [Qemu-devel] [PULL 00/41] Misc changes for 2017-01-27, Peter Maydell, 2017/01/27