LXR linux/arch/sh/kernel/process.c

   1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/mm.h>
   3#include <linux/kernel.h>
   4#include <linux/slab.h>
   5#include <linux/sched/signal.h>
   6#include <linux/sched/task_stack.h>
   7#include <linux/export.h>
   8#include <linux/stackprotector.h>
   9#include <asm/fpu.h>
  10#include <asm/ptrace.h>
  11
  12struct kmem_cache *task_xstate_cachep = NULL;
  13unsigned int xstate_size;
  14
  15#ifdef CONFIG_STACKPROTECTOR
  16unsigned long __stack_chk_guard __read_mostly;
  17EXPORT_SYMBOL(__stack_chk_guard);
  18#endif
  19
  20/*
  21 * this gets called so that we can store lazy state into memory and copy the
  22 * current task into the new thread.
  23 */
  24int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
  25{
  26        unlazy_fpu(src, task_pt_regs(src));
  27        *dst = *src;
  28
  29        if (src->thread.xstate) {
  30                dst->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
  31                                                      GFP_KERNEL);
  32                if (!dst->thread.xstate)
  33                        return -ENOMEM;
  34                memcpy(dst->thread.xstate, src->thread.xstate, xstate_size);
  35        }
  36
  37        return 0;
  38}
  39
  40void free_thread_xstate(struct task_struct *tsk)
  41{
  42        if (tsk->thread.xstate) {
  43                kmem_cache_free(task_xstate_cachep, tsk->thread.xstate);
  44                tsk->thread.xstate = NULL;
  45        }
  46}
  47
  48void arch_release_task_struct(struct task_struct *tsk)
  49{
  50        free_thread_xstate(tsk);
  51}
  52
  53void arch_task_cache_init(void)
  54{
  55        if (!xstate_size)
  56                return;
  57
  58        task_xstate_cachep = kmem_cache_create("task_xstate", xstate_size,
  59                                               __alignof__(union thread_xstate),
  60                                               SLAB_PANIC, NULL);
  61}
  62
  63#ifdef CONFIG_SH_FPU_EMU
  64# define HAVE_SOFTFP    1
  65#else
  66# define HAVE_SOFTFP    0
  67#endif
  68
  69void init_thread_xstate(void)
  70{
  71        if (boot_cpu_data.flags & CPU_HAS_FPU)
  72                xstate_size = sizeof(struct sh_fpu_hard_struct);
  73        else if (HAVE_SOFTFP)
  74                xstate_size = sizeof(struct sh_fpu_soft_struct);
  75        else
  76                xstate_size = 0;
  77}
  78