include/linux/stacktrace.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __LINUX_STACKTRACE_H
   3 #define __LINUX_STACKTRACE_H
   4
   5 #include <linux/types.h>
   6 #include <asm/errno.h>
   7
   8 struct task_struct;
   9 struct pt_regs;
  10
  11 #ifdef CONFIG_ARCH_STACKWALK
  12
  13 /**
  14  * stack_trace_consume_fn - Callback for arch_stack_walk()
  15  * @cookie:     Caller supplied pointer handed back by arch_stack_walk()
  16  * @addr:       The stack entry address to consume
  17  *
  18  * Return:      True, if the entry was consumed or skipped
  19  *              False, if there is no space left to store
  20  */
  21 typedef bool (*stack_trace_consume_fn)(void *cookie, unsigned long addr);
  22 /**
  23  * arch_stack_walk - Architecture specific function to walk the stack
  24  * @consume_entry:      Callback which is invoked by the architecture code for
  25  *                      each entry.
  26  * @cookie:             Caller supplied pointer which is handed back to
  27  *                      @consume_entry
  28  * @task:               Pointer to a task struct, can be NULL
  29  * @regs:               Pointer to registers, can be NULL
  30  *
  31  * ============ ======= ============================================
  32  * task         regs
  33  * ============ ======= ============================================
  34  * task         NULL    Stack trace from task (can be current)
  35  * current      regs    Stack trace starting on regs->stackpointer
  36  * ============ ======= ============================================
  37  */
  38 void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
  39                      struct task_struct *task, struct pt_regs *regs);
  40
  41 /**
  42  * arch_stack_walk_reliable - Architecture specific function to walk the
  43  *                            stack reliably
  44  *
  45  * @consume_entry:      Callback which is invoked by the architecture code for
  46  *                      each entry.
  47  * @cookie:             Caller supplied pointer which is handed back to
  48  *                      @consume_entry
  49  * @task:               Pointer to a task struct, can be NULL
  50  *
  51  * This function returns an error if it detects any unreliable
  52  * features of the stack. Otherwise it guarantees that the stack
  53  * trace is reliable.
  54  *
  55  * If the task is not 'current', the caller *must* ensure the task is
  56  * inactive and its stack is pinned.
  57  */
  58 int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry, void *cookie,
  59                              struct task_struct *task);
  60
  61 void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie,
  62                           const struct pt_regs *regs);
  63 #endif /* CONFIG_ARCH_STACKWALK */
  64
  65 #ifdef CONFIG_STACKTRACE
  66 void stack_trace_print(const unsigned long *trace, unsigned int nr_entries,
  67                        int spaces);
  68 int stack_trace_snprint(char *buf, size_t size, const unsigned long *entries,
  69                         unsigned int nr_entries, int spaces);
  70 unsigned int stack_trace_save(unsigned long *store, unsigned int size,
  71                               unsigned int skipnr);
  72 unsigned int stack_trace_save_tsk(struct task_struct *task,
  73                                   unsigned long *store, unsigned int size,
  74                                   unsigned int skipnr);
  75 unsigned int stack_trace_save_regs(struct pt_regs *regs, unsigned long *store,
  76                                    unsigned int size, unsigned int skipnr);
  77 unsigned int stack_trace_save_user(unsigned long *store, unsigned int size);
  78 unsigned int filter_irq_stacks(unsigned long *entries, unsigned int nr_entries);
  79
  80 #ifndef CONFIG_ARCH_STACKWALK
  81 /* Internal interfaces. Do not use in generic code */
  82 struct stack_trace {
  83         unsigned int nr_entries, max_entries;
  84         unsigned long *entries;
  85         unsigned int skip;      /* input argument: How many entries to skip */
  86 };
  87
  88 extern void save_stack_trace(struct stack_trace *trace);
  89 extern void save_stack_trace_regs(struct pt_regs *regs,
  90                                   struct stack_trace *trace);
  91 extern void save_stack_trace_tsk(struct task_struct *tsk,
  92                                 struct stack_trace *trace);
  93 extern int save_stack_trace_tsk_reliable(struct task_struct *tsk,
  94                                          struct stack_trace *trace);
  95 extern void save_stack_trace_user(struct stack_trace *trace);
  96 #endif /* !CONFIG_ARCH_STACKWALK */
  97 #endif /* CONFIG_STACKTRACE */
  98
  99 #if defined(CONFIG_STACKTRACE) && defined(CONFIG_HAVE_RELIABLE_STACKTRACE)
 100 int stack_trace_save_tsk_reliable(struct task_struct *tsk, unsigned long *store,
 101                                   unsigned int size);
 102 #else
 103 static inline int stack_trace_save_tsk_reliable(struct task_struct *tsk,
 104                                                 unsigned long *store,
 105                                                 unsigned int size)
 106 {
 107         return -ENOSYS;
 108 }
 109 #endif
 110
 111 #endif /* __LINUX_STACKTRACE_H */