2 * Stack trace management functions
4 * Copyright (C) 2006-2009 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
6 #include <linux/sched.h>
7 #include <linux/sched/debug.h>
8 #include <linux/sched/task_stack.h>
9 #include <linux/stacktrace.h>
10 #include <linux/export.h>
11 #include <linux/uaccess.h>
12 #include <asm/stacktrace.h>
13 #include <asm/unwind.h>
15 static int save_stack_address(struct stack_trace *trace, unsigned long addr,
18 if (nosched && in_sched_functions(addr))
21 if (trace->skip > 0) {
26 if (trace->nr_entries >= trace->max_entries)
29 trace->entries[trace->nr_entries++] = addr;
33 static void __save_stack_trace(struct stack_trace *trace,
34 struct task_struct *task, struct pt_regs *regs,
37 struct unwind_state state;
41 save_stack_address(trace, regs->ip, nosched);
43 for (unwind_start(&state, task, regs, NULL); !unwind_done(&state);
44 unwind_next_frame(&state)) {
45 addr = unwind_get_return_address(&state);
46 if (!addr || save_stack_address(trace, addr, nosched))
50 if (trace->nr_entries < trace->max_entries)
51 trace->entries[trace->nr_entries++] = ULONG_MAX;
55 * Save stack-backtrace addresses into a stack_trace buffer.
57 void save_stack_trace(struct stack_trace *trace)
59 __save_stack_trace(trace, current, NULL, false);
61 EXPORT_SYMBOL_GPL(save_stack_trace);
63 void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
65 __save_stack_trace(trace, current, regs, false);
68 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
70 if (!try_get_task_stack(tsk))
73 __save_stack_trace(trace, tsk, NULL, true);
77 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
79 /* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */
81 struct stack_frame_user {
82 const void __user *next_fp;
83 unsigned long ret_addr;
87 copy_stack_frame(const void __user *fp, struct stack_frame_user *frame)
91 if (!access_ok(VERIFY_READ, fp, sizeof(*frame)))
96 if (__copy_from_user_inatomic(frame, fp, sizeof(*frame)))
103 static inline void __save_stack_trace_user(struct stack_trace *trace)
105 const struct pt_regs *regs = task_pt_regs(current);
106 const void __user *fp = (const void __user *)regs->bp;
108 if (trace->nr_entries < trace->max_entries)
109 trace->entries[trace->nr_entries++] = regs->ip;
111 while (trace->nr_entries < trace->max_entries) {
112 struct stack_frame_user frame;
114 frame.next_fp = NULL;
116 if (!copy_stack_frame(fp, &frame))
118 if ((unsigned long)fp < regs->sp)
120 if (frame.ret_addr) {
121 trace->entries[trace->nr_entries++] =
124 if (fp == frame.next_fp)
130 void save_stack_trace_user(struct stack_trace *trace)
133 * Trace user stack if we are not a kernel thread
136 __save_stack_trace_user(trace);
138 if (trace->nr_entries < trace->max_entries)
139 trace->entries[trace->nr_entries++] = ULONG_MAX;