On Thu, Feb 04, 2016 at 02:39:07PM +0000, Russell King - ARM Linux wrote:
> However, this one should warn:
>
> int test_wrong(char **v, const char **p)
> { return __get_user(*v, p); }
>
> Good luck (I think you'll need lots of it to get a working solution)! :)
This works with your test cases on x86-32. Note that it's only compile +
link tested at present.
-ben
--
"Thought is the essence of where you are now."
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 09b1b0a..d8834c2 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -326,7 +326,21 @@ do {
\
} while (0)
#ifdef CONFIG_X86_32
-#define __get_user_asm_u64(x, ptr, retval, errret) (x) = __get_user_bad()
+#define __get_user_asm_u64(x, addr, err, errret) \
+ asm volatile(ASM_STAC "\n" \
+ "1: movl %2,%%eax\n" \
+ " movl %3,%%edx\n" \
+ "2: " ASM_CLAC "\n" \
+ ".section .fixup,\"ax\"\n" \
+ "3: mov %4,%0\n" \
+ " xorl %%eax,%%eax\n" \
+ " xorl %%edx,%%edx\n" \
+ " jmp 2b\n" \
+ ".previous\n" \
+ _ASM_EXTABLE(1b, 3b) \
+ : "=r" (err), "=A"(x) \
+ : "m" (__m(addr)), "m" __m(((u32 *)addr) + 1), "i"
(errret), "0" (err))
+
#define __get_user_asm_ex_u64(x, ptr) (x) = __get_user_bad()
#else
#define __get_user_asm_u64(x, ptr, retval, errret) \
