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riscv/uaccess: Use unsafe wrappers for ASM GOTO

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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
This commit is contained in:
Thomas Gleixner 2025-10-27 09:43:50 +01:00 committed by Peter Zijlstra
parent 5002dd5314
commit 0988ea18c6
1 changed files with 4 additions and 4 deletions
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8
arch/riscv/include/asm/uaccess.h
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@ -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; \