| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | #ifndef _ASM_X86_UNWIND_H |
| 3 | #define _ASM_X86_UNWIND_H |
| 4 | |
| 5 | #include <linux/sched.h> |
| 6 | #include <linux/ftrace.h> |
| 7 | #include <asm/ptrace.h> |
| 8 | #include <asm/stacktrace.h> |
| 9 | |
| 10 | #define IRET_FRAME_OFFSET (offsetof(struct pt_regs, ip)) |
| 11 | #define IRET_FRAME_SIZE (sizeof(struct pt_regs) - IRET_FRAME_OFFSET) |
| 12 | |
| 13 | struct unwind_state { |
| 14 | struct stack_info stack_info; |
| 15 | unsigned long stack_mask; |
| 16 | struct task_struct *task; |
| 17 | int graph_idx; |
| 18 | bool error; |
| 19 | #if defined(CONFIG_UNWINDER_ORC) |
| 20 | bool signal, full_regs; |
| 21 | unsigned long sp, bp, ip; |
| 22 | struct pt_regs *regs; |
| 23 | #elif defined(CONFIG_UNWINDER_FRAME_POINTER) |
| 24 | bool got_irq; |
| 25 | unsigned long *bp, *orig_sp, ip; |
| 26 | struct pt_regs *regs; |
| 27 | #else |
| 28 | unsigned long *sp; |
| 29 | #endif |
| 30 | }; |
| 31 | |
| 32 | void __unwind_start(struct unwind_state *state, struct task_struct *task, |
| 33 | struct pt_regs *regs, unsigned long *first_frame); |
| 34 | bool unwind_next_frame(struct unwind_state *state); |
| 35 | unsigned long unwind_get_return_address(struct unwind_state *state); |
| 36 | unsigned long *unwind_get_return_address_ptr(struct unwind_state *state); |
| 37 | |
| 38 | static inline bool unwind_done(struct unwind_state *state) |
| 39 | { |
| 40 | return state->stack_info.type == STACK_TYPE_UNKNOWN; |
| 41 | } |
| 42 | |
| 43 | static inline bool unwind_error(struct unwind_state *state) |
| 44 | { |
| 45 | return state->error; |
| 46 | } |
| 47 | |
| 48 | static inline |
| 49 | void unwind_start(struct unwind_state *state, struct task_struct *task, |
| 50 | struct pt_regs *regs, unsigned long *first_frame) |
| 51 | { |
| 52 | first_frame = first_frame ? : get_stack_pointer(task, regs); |
| 53 | |
| 54 | __unwind_start(state, task, regs, first_frame); |
| 55 | } |
| 56 | |
| 57 | #if defined(CONFIG_UNWINDER_ORC) || defined(CONFIG_UNWINDER_FRAME_POINTER) |
| 58 | /* |
| 59 | * If 'partial' returns true, only the iret frame registers are valid. |
| 60 | */ |
| 61 | static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state, |
| 62 | bool *partial) |
| 63 | { |
| 64 | if (unwind_done(state)) |
| 65 | return NULL; |
| 66 | |
| 67 | if (partial) { |
| 68 | #ifdef CONFIG_UNWINDER_ORC |
| 69 | *partial = !state->full_regs; |
| 70 | #else |
| 71 | *partial = false; |
| 72 | #endif |
| 73 | } |
| 74 | |
| 75 | return state->regs; |
| 76 | } |
| 77 | #else |
| 78 | static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state, |
| 79 | bool *partial) |
| 80 | { |
| 81 | return NULL; |
| 82 | } |
| 83 | #endif |
| 84 | |
| 85 | #ifdef CONFIG_UNWINDER_ORC |
| 86 | void unwind_init(void); |
| 87 | void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size, |
| 88 | void *orc, size_t orc_size); |
| 89 | #else |
| 90 | static inline void unwind_init(void) {} |
| 91 | static inline |
| 92 | void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size, |
| 93 | void *orc, size_t orc_size) {} |
| 94 | #endif |
| 95 | |
| 96 | /* |
| 97 | * This disables KASAN checking when reading a value from another task's stack, |
| 98 | * since the other task could be running on another CPU and could have poisoned |
| 99 | * the stack in the meantime. |
| 100 | */ |
| 101 | #define READ_ONCE_TASK_STACK(task, x) \ |
| 102 | ({ \ |
| 103 | unsigned long val; \ |
| 104 | if (task == current) \ |
| 105 | val = READ_ONCE(x); \ |
| 106 | else \ |
| 107 | val = READ_ONCE_NOCHECK(x); \ |
| 108 | val; \ |
| 109 | }) |
| 110 | |
| 111 | static inline bool task_on_another_cpu(struct task_struct *task) |
| 112 | { |
| 113 | #ifdef CONFIG_SMP |
| 114 | return task != current && task->on_cpu; |
| 115 | #else |
| 116 | return false; |
| 117 | #endif |
| 118 | } |
| 119 | |
| 120 | #endif /* _ASM_X86_UNWIND_H */ |