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