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 void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
16 struct task_struct *task, struct pt_regs *regs)
18 struct unwind_state state;
21 if (regs && !consume_entry(cookie, regs->ip, false))
24 for (unwind_start(&state, task, regs, NULL); !unwind_done(&state);
25 unwind_next_frame(&state)) {
26 addr = unwind_get_return_address(&state);
27 if (!addr || !consume_entry(cookie, addr, false))
33 * This function returns an error if it detects any unreliable features of the
34 * stack. Otherwise it guarantees that the stack trace is reliable.
36 * If the task is not 'current', the caller *must* ensure the task is inactive.
38 int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
39 void *cookie, struct task_struct *task)
41 struct unwind_state state;
45 for (unwind_start(&state, task, NULL, NULL);
46 !unwind_done(&state) && !unwind_error(&state);
47 unwind_next_frame(&state)) {
49 regs = unwind_get_entry_regs(&state, NULL);
51 /* Success path for user tasks */
56 * Kernel mode registers on the stack indicate an
57 * in-kernel interrupt or exception (e.g., preemption
58 * or a page fault), which can make frame pointers
61 if (IS_ENABLED(CONFIG_FRAME_POINTER))
65 addr = unwind_get_return_address(&state);
68 * A NULL or invalid return address probably means there's some
69 * generated code which __kernel_text_address() doesn't know
75 if (!consume_entry(cookie, addr, false))
79 /* Check for stack corruption */
80 if (unwind_error(&state))
86 /* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */
88 struct stack_frame_user {
89 const void __user *next_fp;
90 unsigned long ret_addr;
94 copy_stack_frame(const void __user *fp, struct stack_frame_user *frame)
98 if (__range_not_ok(fp, sizeof(*frame), TASK_SIZE))
103 if (__copy_from_user_inatomic(frame, fp, sizeof(*frame)))
110 void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie,
111 const struct pt_regs *regs)
113 const void __user *fp = (const void __user *)regs->bp;
115 if (!consume_entry(cookie, regs->ip, false))
119 struct stack_frame_user frame;
121 frame.next_fp = NULL;
123 if (!copy_stack_frame(fp, &frame))
125 if ((unsigned long)fp < regs->sp)
129 if (!consume_entry(cookie, frame.ret_addr, false))