linux/arch/mips/kernel/signal-common.h
Atsushi Nemoto faea623464 [MIPS] Retry {save,restore}_fp_context if failed in atomic context.
The save_fp_context()/restore_fp_context() might sleep on accessing
user stack and therefore might lose FPU ownership in middle of them.

If these function failed due to "in_atomic" test in do_page_fault,
touch the sigcontext area in non-atomic context and retry these
save/restore operation.

This is a replacement of a (broken) fix which was titled "Allow CpU
exception in kernel partially".

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-04-20 14:58:37 +01:00

47 lines
1.3 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 1994 - 2000 Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
*/
#ifndef __SIGNAL_COMMON_H
#define __SIGNAL_COMMON_H
/* #define DEBUG_SIG */
#ifdef DEBUG_SIG
# define DEBUGP(fmt, args...) printk("%s: " fmt, __FUNCTION__ , ##args)
#else
# define DEBUGP(fmt, args...)
#endif
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
/*
* Determine which stack to use..
*/
extern void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
size_t frame_size);
/*
* install trampoline code to get back from the sig handler
*/
extern int install_sigtramp(unsigned int __user *tramp, unsigned int syscall);
/* Check and clear pending FPU exceptions in saved CSR */
extern int fpcsr_pending(unsigned int __user *fpcsr);
/* Make sure we will not lose FPU ownership */
#ifdef CONFIG_PREEMPT
#define lock_fpu_owner() preempt_disable()
#define unlock_fpu_owner() preempt_enable()
#else
#define lock_fpu_owner() pagefault_disable()
#define unlock_fpu_owner() pagefault_enable()
#endif
#endif /* __SIGNAL_COMMON_H */