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 /* 27 * If non-NULL: The current frame is incomplete and doesn't contain a 28 * valid BP. When looking for the next frame, use this instead of the 29 * non-existent saved BP. 30 */ 31 unsigned long *next_bp; 32 struct pt_regs *regs; 33 #else 34 unsigned long *sp; 35 #endif 36 }; 37 38 void __unwind_start(struct unwind_state *state, struct task_struct *task, 39 struct pt_regs *regs, unsigned long *first_frame); 40 bool unwind_next_frame(struct unwind_state *state); 41 unsigned long unwind_get_return_address(struct unwind_state *state); 42 unsigned long *unwind_get_return_address_ptr(struct unwind_state *state); 43 44 static inline bool unwind_done(struct unwind_state *state) 45 { 46 return state->stack_info.type == STACK_TYPE_UNKNOWN; 47 } 48 49 static inline bool unwind_error(struct unwind_state *state) 50 { 51 return state->error; 52 } 53 54 static inline 55 void unwind_start(struct unwind_state *state, struct task_struct *task, 56 struct pt_regs *regs, unsigned long *first_frame) 57 { 58 first_frame = first_frame ? : get_stack_pointer(task, regs); 59 60 __unwind_start(state, task, regs, first_frame); 61 } 62 63 #if defined(CONFIG_UNWINDER_ORC) || defined(CONFIG_UNWINDER_FRAME_POINTER) 64 /* 65 * If 'partial' returns true, only the iret frame registers are valid. 66 */ 67 static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state, 68 bool *partial) 69 { 70 if (unwind_done(state)) 71 return NULL; 72 73 if (partial) { 74 #ifdef CONFIG_UNWINDER_ORC 75 *partial = !state->full_regs; 76 #else 77 *partial = false; 78 #endif 79 } 80 81 return state->regs; 82 } 83 #else 84 static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state, 85 bool *partial) 86 { 87 return NULL; 88 } 89 #endif 90 91 #ifdef CONFIG_UNWINDER_ORC 92 void unwind_init(void); 93 void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size, 94 void *orc, size_t orc_size); 95 #else 96 static inline void unwind_init(void) {} 97 static inline 98 void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size, 99 void *orc, size_t orc_size) {} 100 #endif 101 102 /* 103 * This disables KASAN checking when reading a value from another task's stack, 104 * since the other task could be running on another CPU and could have poisoned 105 * the stack in the meantime. 106 */ 107 #define READ_ONCE_TASK_STACK(task, x) \ 108 ({ \ 109 unsigned long val; \ 110 if (task == current) \ 111 val = READ_ONCE(x); \ 112 else \ 113 val = READ_ONCE_NOCHECK(x); \ 114 val; \ 115 }) 116 117 static inline bool task_on_another_cpu(struct task_struct *task) 118 { 119 #ifdef CONFIG_SMP 120 return task != current && task->on_cpu; 121 #else 122 return false; 123 #endif 124 } 125 126 #endif /* _ASM_X86_UNWIND_H */ 127