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;
  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
  32void __unwind_start(struct unwind_state *state, struct task_struct *task,
  33                    struct pt_regs *regs, unsigned long *first_frame);
  34bool unwind_next_frame(struct unwind_state *state);
  35unsigned long unwind_get_return_address(struct unwind_state *state);
  36unsigned long *unwind_get_return_address_ptr(struct unwind_state *state);
  37
  38static inline bool unwind_done(struct unwind_state *state)
  39{
  40        return state->stack_info.type == STACK_TYPE_UNKNOWN;
  41}
  42
  43static inline bool unwind_error(struct unwind_state *state)
  44{
  45        return state->error;
  46}
  47
  48static inline
  49void 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 */
  61static 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
  78static 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
  86void unwind_init(void);
  87void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
  88                        void *orc, size_t orc_size);
  89#else
  90static inline void unwind_init(void) {}
  91static inline
  92void 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
 111static 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 */
 121