arch/x86/include/asm/unwind.h

   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 */