[PATCH 1/3] x86: Use pt_regs pointer in do_device_not_available()

[Brian Gerst <brgerst@gmail.com>]

The generic exception handler (error_code) passes in the pt_regs
pointer and the error code (unused in this case).  The commit
"x86: fix math_emu register frame access" changed this to pass by
value, which doesn't work correctly with stack protector enabled.
Change it back to use the pt_regs pointer.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/include/asm/traps.h |    2 +-
 arch/x86/kernel/traps.c      |    9 +++++----
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index cf3bb05..0d53425 100644
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -41,7 +41,7 @@ dotraplinkage void do_int3(struct pt_regs *, long);
 dotraplinkage void do_overflow(struct pt_regs *, long);
 dotraplinkage void do_bounds(struct pt_regs *, long);
 dotraplinkage void do_invalid_op(struct pt_regs *, long);
-dotraplinkage void do_device_not_available(struct pt_regs);
+dotraplinkage void do_device_not_available(struct pt_regs *, long);
 dotraplinkage void do_coprocessor_segment_overrun(struct pt_regs *, long);
 dotraplinkage void do_invalid_TSS(struct pt_regs *, long);
 dotraplinkage void do_segment_not_present(struct pt_regs *, long);
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 3b7b2e1..71a8f87 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -905,19 +905,20 @@ void math_emulate(struct math_emu_info *info)
 }
 #endif /* CONFIG_MATH_EMULATION */
 
-dotraplinkage void __kprobes do_device_not_available(struct pt_regs regs)
+dotraplinkage void __kprobes
+do_device_not_available(struct pt_regs *regs, long error_code)
 {
 #ifdef CONFIG_X86_32
 	if (read_cr0() & X86_CR0_EM) {
 		struct math_emu_info info = { };
 
-		conditional_sti(&regs);
+		conditional_sti(regs);
 
-		info.regs = &regs;
+		info.regs = regs;
 		math_emulate(&info);
 	} else {
 		math_state_restore(); /* interrupts still off */
-		conditional_sti(&regs);
+		conditional_sti(regs);
 	}
 #else
 	math_state_restore();
-- 
1.6.1