x86: signal: introduce helper align_sigframe()

Impact: cleanup

Introduce helper align_sigframe() to align stack pointer for signal frame.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Hiroshi Shimamoto 2009-02-27 10:30:32 -08:00 committed by Ingo Molnar
parent 75779f0526
commit 1fae0279ce

View File

@ -191,6 +191,20 @@ setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
/*
* Determine which stack to use..
*/
static unsigned long align_sigframe(unsigned long sp)
{
#ifdef CONFIG_X86_32
/*
* Align the stack pointer according to the i386 ABI,
* i.e. so that on function entry ((sp + 4) & 15) == 0.
*/
sp = ((sp + 4) & -16ul) - 4;
#else /* !CONFIG_X86_32 */
sp = round_down(sp, 16) - 8;
#endif
return sp;
}
static inline void __user *
get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
void __user **fpstate)
@ -236,18 +250,7 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
return (void __user *)-1L;
}
sp -= frame_size;
#ifdef CONFIG_X86_32
/*
* Align the stack pointer according to the i386 ABI,
* i.e. so that on function entry ((sp + 4) & 15) == 0.
*/
sp = ((sp + 4) & -16ul) - 4;
#else /* !CONFIG_X86_32 */
sp = round_down(sp, 16) - 8;
#endif
return (void __user *) sp;
return (void __user *)align_sigframe(sp - frame_size);
}
#ifdef CONFIG_X86_32