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
12 struct kmem_cache *task_xstate_cachep = NULL;
13 unsigned int xstate_size;
14
15 #ifdef CONFIG_STACKPROTECTOR
16 unsigned long __stack_chk_guard __read_mostly;
17 EXPORT_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 */
arch_dup_task_struct(struct task_struct * dst,struct task_struct * src)24 int 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
free_thread_xstate(struct task_struct * tsk)40 void 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
arch_release_task_struct(struct task_struct * tsk)48 void arch_release_task_struct(struct task_struct *tsk)
49 {
50 free_thread_xstate(tsk);
51 }
52
arch_task_cache_init(void)53 void 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
init_thread_xstate(void)69 void 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