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