linux/arch/sh/kernel/dump_task.c
Paul Mundt 9bbafce2ee sh: Fix occasional FPU register corruption under preempt.
Presently with preempt enabled there's the possibility to be preempted
after the TIF_USEDFPU test and the register save, leading to bogus
state post-__switch_to(). Use an explicit preempt_disable()/enable()
pair around unlazy_fpu()/clear_fpu() to avoid this. Follows the x86
change.

Reported-by: Takuo Koguchi <takuo.koguchi.sw@hitachi.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-03-26 19:02:47 +09:00

33 lines
615 B
C

#include <linux/elfcore.h>
#include <linux/sched.h>
#include <asm/fpu.h>
/*
* Capture the user space registers if the task is not running (in user space)
*/
int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
{
struct pt_regs ptregs;
ptregs = *task_pt_regs(tsk);
elf_core_copy_regs(regs, &ptregs);
return 1;
}
int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpu)
{
int fpvalid = 0;
#if defined(CONFIG_SH_FPU)
fpvalid = !!tsk_used_math(tsk);
if (fpvalid) {
unlazy_fpu(tsk, task_pt_regs(tsk));
memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
}
#endif
return fpvalid;
}