[PATCH] kprobes, x86/ptrace.h: fix regs argument order for i386

[Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>]

On i386, the order of parameters passed on regs is eax,edx,and ecx
(as per regparm(3) calling conventions).

Change the mapping in regs_get_kernel_argument(), so that arg1=ax
arg2=dx, and arg3=cx.

Running the selftests testcase kprobes_args_use.tc shows the result
as passed.

Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
---
 arch/x86/include/asm/ptrace.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 40aa69d..d8324a2 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -327,8 +327,8 @@ static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
 	static const unsigned int argument_offs[] = {
 #ifdef __i386__
 		offsetof(struct pt_regs, ax),
-		offsetof(struct pt_regs, cx),
 		offsetof(struct pt_regs, dx),
+		offsetof(struct pt_regs, cx),
 #define NR_REG_ARGUMENTS 3
 #else
 		offsetof(struct pt_regs, di),
-- 
2.7.4