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 } 79