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// SPDX-License-Identifier: GPL-2.0
#include <linux/sched/signal.h>
#include <linux/sched/task.h>
#include <linux/sched/task_stack.h>
#include <linux/slab.h>
#include <asm/processor.h>
#include <asm/fpu.h>
#include <asm/traps.h>
#include <asm/ptrace.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->thread.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)) {
int ret;
/*
* does a slab alloc which can sleep
*/
local_irq_enable();
ret = init_fpu(tsk);
local_irq_disable();
if (ret) {
/*
* ran out of memory!
*/
force_sig(SIGKILL);
return;
}
}
grab_fpu(regs);
__fpu_state_restore();
}
BUILD_TRAP_HANDLER(fpu_state_restore)
{
TRAP_HANDLER_DECL;
fpu_state_restore(regs);
}
#endif /* CONFIG_SH_FPU */
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