arch/sh/kernel/process.c

   1 #include <linux/mm.h>
   2 #include <linux/kernel.h>
   3 #include <linux/slab.h>
   4 #include <linux/sched/signal.h>
   5 #include <linux/sched/task_stack.h>
   6 #include <linux/export.h>
   7 #include <linux/stackprotector.h>
   8 #include <asm/fpu.h>
   9 #include <asm/ptrace.h>
  10
  11 struct kmem_cache *task_xstate_cachep = NULL;
  12 unsigned int xstate_size;
  13
  14 #ifdef CONFIG_CC_STACKPROTECTOR
  15 unsigned long __stack_chk_guard __read_mostly;
  16 EXPORT_SYMBOL(__stack_chk_guard);
  17 #endif
  18
  19 /*
  20  * this gets called so that we can store lazy state into memory and copy the
  21  * current task into the new thread.
  22  */
  23 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
  24 {
  25 #ifdef CONFIG_SUPERH32
  26         unlazy_fpu(src, task_pt_regs(src));
  27 #endif
  28         *dst = *src;
  29
  30         if (src->thread.xstate) {
  31                 dst->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
  32                                                       GFP_KERNEL);
  33                 if (!dst->thread.xstate)
  34                         return -ENOMEM;
  35                 memcpy(dst->thread.xstate, src->thread.xstate, xstate_size);
  36         }
  37
  38         return 0;
  39 }
  40
  41 void free_thread_xstate(struct task_struct *tsk)
  42 {
  43         if (tsk->thread.xstate) {
  44                 kmem_cache_free(task_xstate_cachep, tsk->thread.xstate);
  45                 tsk->thread.xstate = NULL;
  46         }
  47 }
  48
  49 void arch_release_task_struct(struct task_struct *tsk)
  50 {
  51         free_thread_xstate(tsk);
  52 }
  53
  54 void arch_task_cache_init(void)
  55 {
  56         if (!xstate_size)
  57                 return;
  58
  59         task_xstate_cachep = kmem_cache_create("task_xstate", xstate_size,
  60                                                __alignof__(union thread_xstate),
  61                                                SLAB_PANIC | SLAB_NOTRACK, NULL);
  62 }
  63
  64 #ifdef CONFIG_SH_FPU_EMU
  65 # define HAVE_SOFTFP    1
  66 #else
  67 # define HAVE_SOFTFP    0
  68 #endif
  69
  70 void init_thread_xstate(void)
  71 {
  72         if (boot_cpu_data.flags & CPU_HAS_FPU)
  73                 xstate_size = sizeof(struct sh_fpu_hard_struct);
  74         else if (HAVE_SOFTFP)
  75                 xstate_size = sizeof(struct sh_fpu_soft_struct);
  76         else
  77                 xstate_size = 0;
  78 }