mirror of
https://github.com/torvalds/linux.git
synced 2024-11-18 18:11:56 +00:00
4291b730cd
This tosses in a local_irq_enable()/disable() pair around the init_fpu() callsite in the FPU state restore exception handler. Fixes up a slab BUG triggered by making a slab cache allocation that can sleep whilst irqs_disabled(). This follows the behaviour undertaken by the x86 implementation. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
85 lines
1.6 KiB
C
85 lines
1.6 KiB
C
#include <linux/sched.h>
|
|
#include <asm/processor.h>
|
|
#include <asm/fpu.h>
|
|
|
|
int init_fpu(struct task_struct *tsk)
|
|
{
|
|
if (tsk_used_math(tsk)) {
|
|
if ((boot_cpu_data.flags & CPU_HAS_FPU) && tsk == current)
|
|
unlazy_fpu(tsk, task_pt_regs(tsk));
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Memory allocation at the first usage of the FPU and other state.
|
|
*/
|
|
if (!tsk->thread.xstate) {
|
|
tsk->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
|
|
GFP_KERNEL);
|
|
if (!tsk->thread.xstate)
|
|
return -ENOMEM;
|
|
}
|
|
|
|
if (boot_cpu_data.flags & CPU_HAS_FPU) {
|
|
struct sh_fpu_hard_struct *fp = &tsk->thread.xstate->hardfpu;
|
|
memset(fp, 0, xstate_size);
|
|
fp->fpscr = FPSCR_INIT;
|
|
} else {
|
|
struct sh_fpu_soft_struct *fp = &tsk->thread.xstate->softfpu;
|
|
memset(fp, 0, xstate_size);
|
|
fp->fpscr = FPSCR_INIT;
|
|
}
|
|
|
|
set_stopped_child_used_math(tsk);
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_SH_FPU
|
|
void __fpu_state_restore(void)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
|
|
restore_fpu(tsk);
|
|
|
|
task_thread_info(tsk)->status |= TS_USEDFPU;
|
|
tsk->fpu_counter++;
|
|
}
|
|
|
|
void fpu_state_restore(struct pt_regs *regs)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
|
|
if (unlikely(!user_mode(regs))) {
|
|
printk(KERN_ERR "BUG: FPU is used in kernel mode.\n");
|
|
BUG();
|
|
return;
|
|
}
|
|
|
|
if (!tsk_used_math(tsk)) {
|
|
local_irq_enable();
|
|
/*
|
|
* does a slab alloc which can sleep
|
|
*/
|
|
if (init_fpu(tsk)) {
|
|
/*
|
|
* ran out of memory!
|
|
*/
|
|
do_group_exit(SIGKILL);
|
|
return;
|
|
}
|
|
local_irq_disable();
|
|
}
|
|
|
|
grab_fpu(regs);
|
|
|
|
__fpu_state_restore();
|
|
}
|
|
|
|
BUILD_TRAP_HANDLER(fpu_state_restore)
|
|
{
|
|
TRAP_HANDLER_DECL;
|
|
|
|
fpu_state_restore(regs);
|
|
}
|
|
#endif /* CONFIG_SH_FPU */
|