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 */
arch_dup_task_struct(struct task_struct * dst,struct task_struct * src)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
free_thread_xstate(struct task_struct * tsk)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
arch_release_task_struct(struct task_struct * tsk)47 void arch_release_task_struct(struct task_struct *tsk)
48 {
49 free_thread_xstate(tsk);
50 }
51
arch_task_cache_init(void)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
init_thread_xstate(void)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 }
77