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 * WARNING: The entire pt_regs may not be safe to dereference. In some cases, 60 * only the iret frame registers are accessible. Use with caution! 61 */ 62 static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state) 63 { 64 if (unwind_done(state)) 65 return NULL; 66 67 return state->regs; 68 } 69 #else 70 static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state) 71 { 72 return NULL; 73 } 74 #endif 75 76 #ifdef CONFIG_UNWINDER_ORC 77 void unwind_init(void); 78 void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size, 79 void *orc, size_t orc_size); 80 #else 81 static inline void unwind_init(void) {} 82 static inline 83 void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size, 84 void *orc, size_t orc_size) {} 85 #endif 86 87 /* 88 * This disables KASAN checking when reading a value from another task's stack, 89 * since the other task could be running on another CPU and could have poisoned 90 * the stack in the meantime. 91 */ 92 #define READ_ONCE_TASK_STACK(task, x) \ 93 ({ \ 94 unsigned long val; \ 95 if (task == current) \ 96 val = READ_ONCE(x); \ 97 else \ 98 val = READ_ONCE_NOCHECK(x); \ 99 val; \ 100 }) 101 102 static inline bool task_on_another_cpu(struct task_struct *task) 103 { 104 #ifdef CONFIG_SMP 105 return task != current && task->on_cpu; 106 #else 107 return false; 108 #endif 109 } 110 111 #endif /* _ASM_X86_UNWIND_H */ 112