diff options
| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2020-10-20 07:40:07 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-10-22 14:26:09 +1100 |
| commit | 592bbe9c505d9a0ef69260f8c8263df47da2698e (patch) | |
| tree | 030888035ec694c3472477aa2c53731e8d7804f5 /arch/powerpc | |
| parent | 99f6e9795a68fe23f96a2b5b0be07a3dd9457f99 (diff) | |
| download | linux-592bbe9c505d9a0ef69260f8c8263df47da2698e.tar.gz linux-592bbe9c505d9a0ef69260f8c8263df47da2698e.tar.bz2 linux-592bbe9c505d9a0ef69260f8c8263df47da2698e.zip | |
powerpc/uaccess: Don't use "m<>" constraint with GCC 4.9
GCC 4.9 sometimes fails to build with "m<>" constraint in
inline assembly.
CC lib/iov_iter.o
In file included from ./arch/powerpc/include/asm/cmpxchg.h:6:0,
from ./arch/powerpc/include/asm/atomic.h:11,
from ./include/linux/atomic.h:7,
from ./include/linux/crypto.h:15,
from ./include/crypto/hash.h:11,
from lib/iov_iter.c:2:
lib/iov_iter.c: In function 'iovec_from_user.part.30':
./arch/powerpc/include/asm/uaccess.h:287:2: error: 'asm' operand has impossible constraints
__asm__ __volatile__( \
^
./include/linux/compiler.h:78:42: note: in definition of macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^
./arch/powerpc/include/asm/uaccess.h:583:34: note: in expansion of macro 'unsafe_op_wrap'
#define unsafe_get_user(x, p, e) unsafe_op_wrap(__get_user_allowed(x, p), e)
^
./arch/powerpc/include/asm/uaccess.h:329:10: note: in expansion of macro '__get_user_asm'
case 4: __get_user_asm(x, (u32 __user *)ptr, retval, "lwz"); break; \
^
./arch/powerpc/include/asm/uaccess.h:363:3: note: in expansion of macro '__get_user_size_allowed'
__get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \
^
./arch/powerpc/include/asm/uaccess.h:100:2: note: in expansion of macro '__get_user_nocheck'
__get_user_nocheck((x), (ptr), sizeof(*(ptr)), false)
^
./arch/powerpc/include/asm/uaccess.h:583:49: note: in expansion of macro '__get_user_allowed'
#define unsafe_get_user(x, p, e) unsafe_op_wrap(__get_user_allowed(x, p), e)
^
lib/iov_iter.c:1663:3: note: in expansion of macro 'unsafe_get_user'
unsafe_get_user(len, &uiov[i].iov_len, uaccess_end);
^
make[1]: *** [scripts/Makefile.build:283: lib/iov_iter.o] Error 1
Define a UPD_CONSTR macro that is "<>" by default and
only "" with GCC prior to GCC 5.
Fixes: fcf1f26895a4 ("powerpc/uaccess: Add pre-update addressing to __put_user_asm_goto()")
Fixes: 2f279eeb68b8 ("powerpc/uaccess: Add pre-update addressing to __get_user_asm() and __put_user_asm()")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/212d3bc4a52ca71523759517bb9c61f7e477c46a.1603179582.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/include/asm/asm-const.h | 13 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/uaccess.h | 4 |
2 files changed, 15 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/asm-const.h b/arch/powerpc/include/asm/asm-const.h index 082c1538c562..0ce2368bd20f 100644 --- a/arch/powerpc/include/asm/asm-const.h +++ b/arch/powerpc/include/asm/asm-const.h @@ -11,4 +11,17 @@ # define __ASM_CONST(x) x##UL # define ASM_CONST(x) __ASM_CONST(x) #endif + +/* + * Inline assembly memory constraint + * + * GCC 4.9 doesn't properly handle pre update memory constraint "m<>" + * + */ +#if defined(GCC_VERSION) && GCC_VERSION < 50000 +#define UPD_CONSTR "" +#else +#define UPD_CONSTR "<>" +#endif + #endif /* _ASM_POWERPC_ASM_CONST_H */ diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index 26781b044932..a1c1aab4e038 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -223,7 +223,7 @@ do { \ "1: " op "%U1%X1 %0,%1 # put_user\n" \ EX_TABLE(1b, %l2) \ : \ - : "r" (x), "m<>" (*addr) \ + : "r" (x), "m"UPD_CONSTR (*addr) \ : \ : label) @@ -294,7 +294,7 @@ extern long __get_user_bad(void); ".previous\n" \ EX_TABLE(1b, 3b) \ : "=r" (err), "=r" (x) \ - : "m<>" (*addr), "i" (-EFAULT), "0" (err)) + : "m"UPD_CONSTR (*addr), "i" (-EFAULT), "0" (err)) #ifdef __powerpc64__ #define __get_user_asm2(x, addr, err) \ |