Re: linux-next: build failure after merge of the aio tree
From: Benjamin LaHaise <bcrl@kvack.org>
Date: 2016-02-04 16:01:04
Also in:
linux-arm-kernel, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
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) \