When targetting 32-bit processors, __put_user emits a pair of stw
instructions for the 8-byte case. If the type of __val is a pointer, the
marshalling code casts it to the wider integer type of u64, resulting
in the following compiler warnings:
kernel/signal.c: In function 'copy_siginfo_to_user':
kernel/signal.c:2752:11: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
kernel/signal.c:2752:11: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
[...]
This patch fixes the warnings by removing the marshalling code and using
the correct output modifiers in the __put_{user,kernel}_asm64 macros
so that GCC will allocate the right registers without the need to
extract the two words explicitly.
Cc: Helge Deller <[email protected]>
Signed-off-by: Will Deacon <[email protected]>
---
v1->v2: Put the output modifier on the correct word, so 64-bit put_user
doesn't end up word-swapped.
arch/parisc/include/asm/uaccess.h | 14 ++++----------
1 file changed, 4 insertions(+), 10 deletions(-)
diff --git a/arch/parisc/include/asm/uaccess.h b/arch/parisc/include/asm/uaccess.h
index 4ba2c93..e0a8235 100644
--- a/arch/parisc/include/asm/uaccess.h
+++ b/arch/parisc/include/asm/uaccess.h
@@ -181,30 +181,24 @@ struct exception_data {
#if !defined(CONFIG_64BIT)
#define __put_kernel_asm64(__val,ptr) do { \
- u64 __val64 = (u64)(__val); \
- u32 hi = (__val64) >> 32; \
- u32 lo = (__val64) & 0xffffffff; \
__asm__ __volatile__ ( \
"\n1:\tstw %2,0(%1)" \
- "\n2:\tstw %3,4(%1)\n\t" \
+ "\n2:\tstw %R2,4(%1)\n\t" \
ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_2)\
ASM_EXCEPTIONTABLE_ENTRY(2b,fixup_put_user_skip_1)\
: "=r"(__pu_err) \
- : "r"(ptr), "r"(hi), "r"(lo), "0"(__pu_err) \
+ : "r"(ptr), "r"(__val), "0"(__pu_err) \
: "r1"); \
} while (0)
#define __put_user_asm64(__val,ptr) do { \
- u64 __val64 = (u64)(__val); \
- u32 hi = (__val64) >> 32; \
- u32 lo = (__val64) & 0xffffffff; \
__asm__ __volatile__ ( \
"\n1:\tstw %2,0(%%sr3,%1)" \
- "\n2:\tstw %3,4(%%sr3,%1)\n\t" \
+ "\n2:\tstw %R2,4(%%sr3,%1)\n\t" \
ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_2)\
ASM_EXCEPTIONTABLE_ENTRY(2b,fixup_put_user_skip_1)\
: "=r"(__pu_err) \
- : "r"(ptr), "r"(hi), "r"(lo), "0"(__pu_err) \
+ : "r"(ptr), "r"(__val), "0"(__pu_err) \
: "r1"); \
} while (0)
--
1.8.0