diff options
| author | Michael Ellerman <[email protected]> | 2024-09-16 22:05:10 +1000 |
|---|---|---|
| committer | Michael Ellerman <[email protected]> | 2024-09-17 22:17:57 +1000 |
| commit | 39190ac7cff1fd15135fa8e658030d9646fdb5f2 (patch) | |
| tree | 9acf5bcf56ee6d30d78c400ef279167770f0d239 /arch/powerpc/include/asm/uaccess.h | |
| parent | b77d36bb9a3de774950ba712a0e47f9d33c6f6d7 (diff) | |
powerpc/atomic: Use YZ constraints for DS-form instructions
The 'ld' and 'std' instructions require a 4-byte aligned displacement
because they are DS-form instructions. But the "m" asm constraint
doesn't enforce that.
That can lead to build errors if the compiler chooses a non-aligned
displacement, as seen with GCC 14:
/tmp/ccuSzwiR.s: Assembler messages:
/tmp/ccuSzwiR.s:2579: Error: operand out of domain (39 is not a multiple of 4)
make[5]: *** [scripts/Makefile.build:229: net/core/page_pool.o] Error 1
Dumping the generated assembler shows:
ld 8,39(8) # MEM[(const struct atomic64_t *)_29].counter, t
Use the YZ constraints to tell the compiler either to generate a DS-form
displacement, or use an X-form instruction, either of which prevents the
build error.
See commit 2d43cc701b96 ("powerpc/uaccess: Fix build errors seen with
GCC 13/14") for more details on the constraint letters.
Fixes: 9f0cbea0d8cc ("[POWERPC] Implement atomic{, 64}_{read, write}() without volatile")
Cc: [email protected] # v2.6.24+
Reported-by: Stephen Rothwell <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]
Tested-by: Mina Almasry <[email protected]>
Reviewed-by: Segher Boessenkool <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/[email protected]
Diffstat (limited to 'arch/powerpc/include/asm/uaccess.h')
| -rw-r--r-- | arch/powerpc/include/asm/uaccess.h | 7 |
1 files changed, 1 insertions, 6 deletions
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index fd594bf6c6a9..4f5a46a77fa2 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -6,6 +6,7 @@ #include <asm/page.h> #include <asm/extable.h> #include <asm/kup.h> +#include <asm/asm-compat.h> #ifdef __powerpc64__ /* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */ @@ -92,12 +93,6 @@ __pu_failed: \ : label) #endif -#ifdef CONFIG_CC_IS_CLANG -#define DS_FORM_CONSTRAINT "Z<>" -#else -#define DS_FORM_CONSTRAINT "YZ<>" -#endif - #ifdef __powerpc64__ #ifdef CONFIG_PPC_KERNEL_PREFIXED #define __put_user_asm2_goto(x, ptr, label) \ |