Re: [PATCH] RISC-V: uaccess: Wrap the get_user_8 uaccess macro

From: Alexandre Ghiti
Date: Wed Jun 11 2025 - 03:31:36 EST


On 6/10/25 23:30, Palmer Dabbelt wrote:
From: Palmer Dabbelt <palmer@xxxxxxxxxxx>

I must have lost this rebasing things during the merge window, I know I
got it at some point but it's not here now. Without this I get warnings
along the lines of

include/linux/fs.h:3975:15: warning: label followed by a declaration is a C23 extension [-Wc23-extensions]
3975 | if (unlikely(get_user(c, path)))
| ^
arch/riscv/include/asm/uaccess.h:274:3: note: expanded from macro 'get_user'
274 | __get_user((x), __p) : \
| ^
arch/riscv/include/asm/uaccess.h:244:2: note: expanded from macro '__get_user'
244 | __get_user_error(__gu_val, __gu_ptr, __gu_err); \
| ^
arch/riscv/include/asm/uaccess.h:207:2: note: expanded from macro '__get_user_error'
207 | __ge LD [M] net/802/psnap.ko
t_user_nocheck(x, ptr, __gu_failed); \
| ^
arch/riscv/include/asm/uaccess.h:196:3: note: expanded from macro '__get_user_nocheck'
196 | __get_user_8((x), __gu_ptr, label); \
| ^
arch/riscv/include/asm/uaccess.h:130:2: note: expanded from macro '__get_user_8'
130 | u32 __user *__ptr = (u32 __user *)(ptr); \
| ^

Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxx>
---
arch/riscv/include/asm/uaccess.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h
index d472da4450e6..525e50db24f7 100644
--- a/arch/riscv/include/asm/uaccess.h
+++ b/arch/riscv/include/asm/uaccess.h
@@ -127,6 +127,7 @@ do { \
#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
#define __get_user_8(x, ptr, label) \
+do { \
u32 __user *__ptr = (u32 __user *)(ptr); \
u32 __lo, __hi; \
asm_goto_output( \
@@ -141,7 +142,7 @@ do { \
: : label); \
(x) = (__typeof__(x))((__typeof__((x) - (x)))( \
(((u64)__hi << 32) | __lo))); \
-
+} while (0)
#else /* !CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
#define __get_user_8(x, ptr, label) \
do { \


I had come up with the same fix so:

Reviewed-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>