kernel/arch/sh/kernel/process.c

   1 #include <linux/mm.h>
   2 #include <linux/kernel.h>
   3 #include <linux/slab.h>
   4 #include <linux/sched.h>
   5 #include <linux/export.h>
   6 #include <linux/stackprotector.h>
   7 #include <asm/fpu.h>
   8
   9 struct kmem_cache *task_xstate_cachep = NULL;
  10 unsigned int xstate_size;
  11
  12 #ifdef CONFIG_CC_STACKPROTECTOR
  13 unsigned long __stack_chk_guard __read_mostly;
  14 EXPORT_SYMBOL(__stack_chk_guard);
  15 #endif
  16
  17 /*
  18  * this gets called so that we can store lazy state into memory and copy the
  19  * current task into the new thread.
  20  */
  21 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
  22 {
  23 #ifdef CONFIG_SUPERH32
  24         unlazy_fpu(src, task_pt_regs(src));
  25 #endif
  26         *dst = *src;
  27
  28         if (src->thread.xstate) {
  29                 dst->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
  30                                                       GFP_KERNEL);
  31                 if (!dst->thread.xstate)
  32                         return -ENOMEM;
  33                 memcpy(dst->thread.xstate, src->thread.xstate, xstate_size);
  34         }
  35
  36         return 0;
  37 }
  38
  39 void free_thread_xstate(struct task_struct *tsk)
  40 {
  41         if (tsk->thread.xstate) {
  42                 kmem_cache_free(task_xstate_cachep, tsk->thread.xstate);
  43                 tsk->thread.xstate = NULL;
  44         }
  45 }
  46
  47 void arch_release_task_struct(struct task_struct *tsk)
  48 {
  49         free_thread_xstate(tsk);
  50 }
  51
  52 void arch_task_cache_init(void)
  53 {
  54         if (!xstate_size)
  55                 return;
  56
  57         task_xstate_cachep = kmem_cache_create("task_xstate", xstate_size,
  58                                                __alignof__(union thread_xstate),
  59                                                SLAB_PANIC | SLAB_NOTRACK, NULL);
  60 }
  61
  62 #ifdef CONFIG_SH_FPU_EMU
  63 # define HAVE_SOFTFP    1
  64 #else
  65 # define HAVE_SOFTFP    0
  66 #endif
  67
  68 void init_thread_xstate(void)
  69 {
  70         if (boot_cpu_data.flags & CPU_HAS_FPU)
  71                 xstate_size = sizeof(struct sh_fpu_hard_struct);
  72         else if (HAVE_SOFTFP)
  73                 xstate_size = sizeof(struct sh_fpu_soft_struct);
  74         else
  75                 xstate_size = 0;
  76 }