LXR linux/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
  13struct 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, *prev_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
  38void __unwind_start(struct unwind_state *state, struct task_struct *task,
  39                    struct pt_regs *regs, unsigned long *first_frame);
  40bool unwind_next_frame(struct unwind_state *state);
  41unsigned long unwind_get_return_address(struct unwind_state *state);
  42unsigned long *unwind_get_return_address_ptr(struct unwind_state *state);
  43
  44static inline bool unwind_done(struct unwind_state *state)
  45{
  46        return state->stack_info.type == STACK_TYPE_UNKNOWN;
  47}
  48
  49static inline bool unwind_error(struct unwind_state *state)
  50{
  51        return state->error;
  52}
  53
  54static inline
  55void 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 */
  67static 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
  84static 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
  92void unwind_init(void);
  93void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
  94                        void *orc, size_t orc_size);
  95#else
  96static inline void unwind_init(void) {}
  97static inline
  98void 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
 117static 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