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