alistair23-linux/arch/mips/include/asm/watch.h
James Hogan a7e89326b4 MIPS: Fix watchpoint restoration
Commit f51246efee ("MIPS: Get rid of finish_arch_switch().") moved the
__restore_watch() call from finish_arch_switch() (i.e. after resume()
returns) to before the resume() call in switch_to(). This results in
watchpoints only being restored when a task is descheduled, preventing
the watchpoints from being effective most of the time, except due to
chance before the watchpoints are lazily removed.

Fix the call sequence from switch_to() through to
mips_install_watch_registers() to pass the task_struct pointer of the
next task, instead of using current. This allows the watchpoints for the
next (non-current) task to be restored without reintroducing
finish_arch_switch().

Fixes: f51246efee ("MIPS: Get rid of finish_arch_switch().")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.3.x-
Patchwork: https://patchwork.linux-mips.org/patch/12726/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-09 12:00:02 +02:00

33 lines
827 B
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) 2008 David Daney
*/
#ifndef _ASM_WATCH_H
#define _ASM_WATCH_H
#include <linux/bitops.h>
#include <asm/mipsregs.h>
void mips_install_watch_registers(struct task_struct *t);
void mips_read_watch_registers(void);
void mips_clear_watch_registers(void);
void mips_probe_watch_registers(struct cpuinfo_mips *c);
#ifdef CONFIG_HARDWARE_WATCHPOINTS
#define __restore_watch(task) do { \
if (unlikely(test_bit(TIF_LOAD_WATCH, \
&task_thread_info(task)->flags))) { \
mips_install_watch_registers(task); \
} \
} while (0)
#else
#define __restore_watch(task) do {} while (0)
#endif
#endif /* _ASM_WATCH_H */