[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH 01/14] linux-user: Use memcpy in get_user/put_user.
From: |
Richard Henderson |
Subject: |
[Qemu-devel] [PATCH 01/14] linux-user: Use memcpy in get_user/put_user. |
Date: |
Fri, 21 Sep 2012 19:04:54 -0700 |
When host and target have differing alignment rules, using a cast
and direct memory operation can result in SIGBUS. Use memcpy instead,
which the compiler will happily optimize when alignment is satisfied.
Signed-off-by: Richard Henderson <address@hidden>
Reviewed-by: Peter Maydell <address@hidden>
---
linux-user/qemu.h | 47 +++++++++++++++--------------------------------
1 file changed, 15 insertions(+), 32 deletions(-)
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index 69b27d7..fc4cc00 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -289,46 +289,29 @@ static inline int access_ok(int type, abi_ulong addr,
abi_ulong size)
* struct has been locked - usually with lock_user_struct().
*/
#define __put_user(x, hptr)\
-({\
+({ __typeof(*hptr) pu_ = (x);\
switch(sizeof(*hptr)) {\
- case 1:\
- *(uint8_t *)(hptr) = (uint8_t)(typeof(*hptr))(x);\
- break;\
- case 2:\
- *(uint16_t *)(hptr) = tswap16((uint16_t)(typeof(*hptr))(x));\
- break;\
- case 4:\
- *(uint32_t *)(hptr) = tswap32((uint32_t)(typeof(*hptr))(x));\
- break;\
- case 8:\
- *(uint64_t *)(hptr) = tswap64((typeof(*hptr))(x));\
- break;\
- default:\
- abort();\
+ case 1: break;\
+ case 2: pu_ = tswap16(pu_); break; \
+ case 4: pu_ = tswap32(pu_); break; \
+ case 8: pu_ = tswap64(pu_); break; \
+ default: abort();\
}\
+ memcpy(hptr, &pu_, sizeof(pu_)); \
0;\
})
#define __get_user(x, hptr) \
-({\
+({ __typeof(*hptr) gu_; \
+ memcpy(&gu_, hptr, sizeof(gu_)); \
switch(sizeof(*hptr)) {\
- case 1:\
- x = (typeof(*hptr))*(uint8_t *)(hptr);\
- break;\
- case 2:\
- x = (typeof(*hptr))tswap16(*(uint16_t *)(hptr));\
- break;\
- case 4:\
- x = (typeof(*hptr))tswap32(*(uint32_t *)(hptr));\
- break;\
- case 8:\
- x = (typeof(*hptr))tswap64(*(uint64_t *)(hptr));\
- break;\
- default:\
- /* avoid warning */\
- x = 0;\
- abort();\
+ case 1: break; \
+ case 2: gu_ = tswap16(gu_); break; \
+ case 4: gu_ = tswap32(gu_); break; \
+ case 8: gu_ = tswap64(gu_); break; \
+ default: abort();\
}\
+ (x) = gu_; \
0;\
})
--
1.7.11.4
- [Qemu-devel] [PATCH v3 00/14] Sparc TCG cleanup, Richard Henderson, 2012/09/21
- [Qemu-devel] [PATCH 03/14] tcg-sparc: Fix ADDX opcode., Richard Henderson, 2012/09/21
- [Qemu-devel] [PATCH 04/14] tcg-sparc: Don't MAP_FIXED on top of the program, Richard Henderson, 2012/09/21
- [Qemu-devel] [PATCH 01/14] linux-user: Use memcpy in get_user/put_user.,
Richard Henderson <=
- [Qemu-devel] [PATCH 02/14] tcg-sparc: Hack in qemu_ld/st64 for 32-bit., Richard Henderson, 2012/09/21
- [Qemu-devel] [PATCH 05/14] tcg-sparc: Assume v9 cpu always, i.e. force v8plus in 32-bit mode., Richard Henderson, 2012/09/21
- [Qemu-devel] [PATCH 08/14] tcg-sparc: Change AREG0 in generated code to %i0., Richard Henderson, 2012/09/21
- [Qemu-devel] [PATCH 07/14] tcg-sparc: Support GUEST_BASE., Richard Henderson, 2012/09/21
- [Qemu-devel] [PATCH 09/14] tcg-sparc: Clean up cruft stemming from attempts to use global registers., Richard Henderson, 2012/09/21
- [Qemu-devel] [PATCH 06/14] tcg-sparc: Fix qemu_ld/st to handle 32-bit host., Richard Henderson, 2012/09/21
- [Qemu-devel] [PATCH 10/14] tcg-sparc: Mask shift immediates to avoid illegal insns., Richard Henderson, 2012/09/21
- [Qemu-devel] [PATCH 12/14] tcg-sparc: Add %g/%o registers to alloc_order, Richard Henderson, 2012/09/21
- [Qemu-devel] [PATCH 13/14] tcg-sparc: Fix and enable direct TB chaining., Richard Henderson, 2012/09/21
- [Qemu-devel] [PATCH 14/14] tcg-sparc: Preserve branch destinations during retranslation, Richard Henderson, 2012/09/21