1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Stack trace management functions
 4 *
 5 *  Copyright IBM Corp. 2006
 6 */
 7
 8#include <linux/stacktrace.h>
 
 
 9#include <asm/stacktrace.h>
10#include <asm/unwind.h>
11#include <asm/kprobes.h>
 
12
13void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
14		     struct task_struct *task, struct pt_regs *regs)
15{
16	struct unwind_state state;
17	unsigned long addr;
18
19	unwind_for_each_frame(&state, task, regs, 0) {
20		addr = unwind_get_return_address(&state);
21		if (!addr || !consume_entry(cookie, addr))
22			break;
23	}
24}
25
26int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
27			     void *cookie, struct task_struct *task)
28{
29	struct unwind_state state;
30	unsigned long addr;
31
32	unwind_for_each_frame(&state, task, NULL, 0) {
33		if (state.stack_info.type != STACK_TYPE_TASK)
34			return -EINVAL;
35
36		if (state.regs)
37			return -EINVAL;
38
39		addr = unwind_get_return_address(&state);
40		if (!addr)
41			return -EINVAL;
42
43#ifdef CONFIG_KPROBES
44		/*
45		 * Mark stacktraces with kretprobed functions on them
46		 * as unreliable.
47		 */
48		if (state.ip == (unsigned long)__kretprobe_trampoline)
49			return -EINVAL;
50#endif
51
52		if (!consume_entry(cookie, addr))
53			return -EINVAL;
54	}
55
56	/* Check for stack corruption */
57	if (unwind_error(&state))
58		return -EINVAL;
59	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
60}

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Stack trace management functions
  4 *
  5 *  Copyright IBM Corp. 2006
  6 */
  7
  8#include <linux/stacktrace.h>
  9#include <linux/uaccess.h>
 10#include <linux/compat.h>
 11#include <asm/stacktrace.h>
 12#include <asm/unwind.h>
 13#include <asm/kprobes.h>
 14#include <asm/ptrace.h>
 15
 16void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
 17		     struct task_struct *task, struct pt_regs *regs)
 18{
 19	struct unwind_state state;
 20	unsigned long addr;
 21
 22	unwind_for_each_frame(&state, task, regs, 0) {
 23		addr = unwind_get_return_address(&state);
 24		if (!addr || !consume_entry(cookie, addr))
 25			break;
 26	}
 27}
 28
 29int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
 30			     void *cookie, struct task_struct *task)
 31{
 32	struct unwind_state state;
 33	unsigned long addr;
 34
 35	unwind_for_each_frame(&state, task, NULL, 0) {
 36		if (state.stack_info.type != STACK_TYPE_TASK)
 37			return -EINVAL;
 38
 39		if (state.regs)
 40			return -EINVAL;
 41
 42		addr = unwind_get_return_address(&state);
 43		if (!addr)
 44			return -EINVAL;
 45
 46#ifdef CONFIG_RETHOOK
 47		/*
 48		 * Mark stacktraces with krethook functions on them
 49		 * as unreliable.
 50		 */
 51		if (state.ip == (unsigned long)arch_rethook_trampoline)
 52			return -EINVAL;
 53#endif
 54
 55		if (!consume_entry(cookie, addr))
 56			return -EINVAL;
 57	}
 58
 59	/* Check for stack corruption */
 60	if (unwind_error(&state))
 61		return -EINVAL;
 62	return 0;
 63}
 64
 65void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie,
 66			  const struct pt_regs *regs)
 67{
 68	struct stack_frame_user __user *sf;
 69	unsigned long ip, sp;
 70	bool first = true;
 71
 72	if (is_compat_task())
 73		return;
 74	if (!consume_entry(cookie, instruction_pointer(regs)))
 75		return;
 76	sf = (void __user *)user_stack_pointer(regs);
 77	pagefault_disable();
 78	while (1) {
 79		if (__get_user(sp, &sf->back_chain))
 80			break;
 81		if (__get_user(ip, &sf->gprs[8]))
 82			break;
 83		if (ip & 0x1) {
 84			/*
 85			 * If the instruction address is invalid, and this
 86			 * is the first stack frame, assume r14 has not
 87			 * been written to the stack yet. Otherwise exit.
 88			 */
 89			if (first && !(regs->gprs[14] & 0x1))
 90				ip = regs->gprs[14];
 91			else
 92				break;
 93		}
 94		if (!consume_entry(cookie, ip))
 95			break;
 96		/* Sanity check: ABI requires SP to be aligned 8 bytes. */
 97		if (!sp || sp & 0x7)
 98			break;
 99		sf = (void __user *)sp;
100		first = false;
101	}
102	pagefault_enable();
103}