diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2025-10-27 09:43:50 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2025-11-03 15:26:10 +0100 |
| commit | 0988ea18c6244da3dc35cfc0ad621531d0e1508a (patch) | |
| tree | 64788a3fceaed759b6dc2dc30963533ed0d15acc | |
| parent | 5002dd53144f82d43eba778c927adfa7d429c16a (diff) | |
riscv/uaccess: Use unsafe wrappers for ASM GOTO
ASM GOTO is miscompiled by GCC when it is used inside a auto cleanup scope:
bool foo(u32 __user *p, u32 val)
{
scoped_guard(pagefault)
unsafe_put_user(val, p, efault);
return true;
efault:
return false;
}
It ends up leaking the pagefault disable counter in the fault path. clang
at least fails the build.
Rename unsafe_*_user() to arch_unsafe_*_user() which makes the generic
uaccess header wrap it with a local label that makes both compilers emit
correct code. Same for the kernel_nofault() variants.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20251027083745.419351819@linutronix.de
| -rw-r--r-- | arch/riscv/include/asm/uaccess.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h index f5f4f7f85543..36bba6720c26 100644 --- a/arch/riscv/include/asm/uaccess.h +++ b/arch/riscv/include/asm/uaccess.h @@ -437,10 +437,10 @@ unsigned long __must_check clear_user(void __user *to, unsigned long n) __clear_user(untagged_addr(to), n) : n; } -#define __get_kernel_nofault(dst, src, type, err_label) \ +#define arch_get_kernel_nofault(dst, src, type, err_label) \ __get_user_nocheck(*((type *)(dst)), (__force __user type *)(src), err_label) -#define __put_kernel_nofault(dst, src, type, err_label) \ +#define arch_put_kernel_nofault(dst, src, type, err_label) \ __put_user_nocheck(*((type *)(src)), (__force __user type *)(dst), err_label) static __must_check __always_inline bool user_access_begin(const void __user *ptr, size_t len) @@ -460,10 +460,10 @@ static inline void user_access_restore(unsigned long enabled) { } * We want the unsafe accessors to always be inlined and use * the error labels - thus the macro games. */ -#define unsafe_put_user(x, ptr, label) \ +#define arch_unsafe_put_user(x, ptr, label) \ __put_user_nocheck(x, (ptr), label) -#define unsafe_get_user(x, ptr, label) do { \ +#define arch_unsafe_get_user(x, ptr, label) do { \ __inttype(*(ptr)) __gu_val; \ __get_user_nocheck(__gu_val, (ptr), label); \ (x) = (__force __typeof__(*(ptr)))__gu_val; \ |