arch/x86/include/asm/unwind.h

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