Ingo Molnar | 21b32bb | 2006-07-03 00:24:40 -0700 | [diff] [blame] | 1 | /* |
Ingo Molnar | 21b32bb | 2006-07-03 00:24:40 -0700 | [diff] [blame] | 2 | * Stack trace management functions |
| 3 | * |
Ingo Molnar | 8f47e16 | 2009-01-31 02:03:42 +0100 | [diff] [blame] | 4 | * Copyright (C) 2006-2009 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> |
Ingo Molnar | 21b32bb | 2006-07-03 00:24:40 -0700 | [diff] [blame] | 5 | */ |
| 6 | #include <linux/sched.h> |
| 7 | #include <linux/stacktrace.h> |
Paul Gortmaker | 186f436 | 2016-07-13 20:18:56 -0400 | [diff] [blame] | 8 | #include <linux/export.h> |
Török Edwin | 02b6751 | 2008-11-22 13:28:47 +0200 | [diff] [blame] | 9 | #include <linux/uaccess.h> |
Andi Kleen | c0b766f | 2006-09-26 10:52:34 +0200 | [diff] [blame] | 10 | #include <asm/stacktrace.h> |
Josh Poimboeuf | 49a612c | 2016-09-16 14:18:14 -0500 | [diff] [blame] | 11 | #include <asm/unwind.h> |
Ingo Molnar | 21b32bb | 2006-07-03 00:24:40 -0700 | [diff] [blame] | 12 | |
Josh Poimboeuf | 49a612c | 2016-09-16 14:18:14 -0500 | [diff] [blame] | 13 | static int save_stack_address(struct stack_trace *trace, unsigned long addr, |
| 14 | bool nosched) |
Ingo Molnar | 21b32bb | 2006-07-03 00:24:40 -0700 | [diff] [blame] | 15 | { |
Oleg Nesterov | 018378c | 2010-06-03 21:32:43 +0200 | [diff] [blame] | 16 | if (nosched && in_sched_functions(addr)) |
Alexei Starovoitov | 568b329 | 2016-02-17 19:58:57 -0800 | [diff] [blame] | 17 | return 0; |
Josh Poimboeuf | 49a612c | 2016-09-16 14:18:14 -0500 | [diff] [blame] | 18 | |
Andi Kleen | c0b766f | 2006-09-26 10:52:34 +0200 | [diff] [blame] | 19 | if (trace->skip > 0) { |
| 20 | trace->skip--; |
Alexei Starovoitov | 568b329 | 2016-02-17 19:58:57 -0800 | [diff] [blame] | 21 | return 0; |
Andi Kleen | c0b766f | 2006-09-26 10:52:34 +0200 | [diff] [blame] | 22 | } |
Josh Poimboeuf | 49a612c | 2016-09-16 14:18:14 -0500 | [diff] [blame] | 23 | |
| 24 | if (trace->nr_entries >= trace->max_entries) |
| 25 | return -1; |
| 26 | |
| 27 | trace->entries[trace->nr_entries++] = addr; |
| 28 | return 0; |
| 29 | } |
| 30 | |
| 31 | static void __save_stack_trace(struct stack_trace *trace, |
| 32 | struct task_struct *task, struct pt_regs *regs, |
| 33 | bool nosched) |
| 34 | { |
| 35 | struct unwind_state state; |
| 36 | unsigned long addr; |
| 37 | |
| 38 | if (regs) |
| 39 | save_stack_address(trace, regs->ip, nosched); |
| 40 | |
| 41 | for (unwind_start(&state, task, regs, NULL); !unwind_done(&state); |
| 42 | unwind_next_frame(&state)) { |
| 43 | addr = unwind_get_return_address(&state); |
| 44 | if (!addr || save_stack_address(trace, addr, nosched)) |
| 45 | break; |
Alexei Starovoitov | 568b329 | 2016-02-17 19:58:57 -0800 | [diff] [blame] | 46 | } |
Josh Poimboeuf | 49a612c | 2016-09-16 14:18:14 -0500 | [diff] [blame] | 47 | |
| 48 | if (trace->nr_entries < trace->max_entries) |
| 49 | trace->entries[trace->nr_entries++] = ULONG_MAX; |
Andi Kleen | c0b766f | 2006-09-26 10:52:34 +0200 | [diff] [blame] | 50 | } |
| 51 | |
Ingo Molnar | 21b32bb | 2006-07-03 00:24:40 -0700 | [diff] [blame] | 52 | /* |
| 53 | * Save stack-backtrace addresses into a stack_trace buffer. |
Ingo Molnar | 21b32bb | 2006-07-03 00:24:40 -0700 | [diff] [blame] | 54 | */ |
Christoph Hellwig | ab1b6f0 | 2007-05-08 00:23:29 -0700 | [diff] [blame] | 55 | void save_stack_trace(struct stack_trace *trace) |
Ingo Molnar | 21b32bb | 2006-07-03 00:24:40 -0700 | [diff] [blame] | 56 | { |
Josh Poimboeuf | 49a612c | 2016-09-16 14:18:14 -0500 | [diff] [blame] | 57 | __save_stack_trace(trace, current, NULL, false); |
Ingo Molnar | 21b32bb | 2006-07-03 00:24:40 -0700 | [diff] [blame] | 58 | } |
Ingo Molnar | 8594698 | 2008-06-27 21:20:17 +0200 | [diff] [blame] | 59 | EXPORT_SYMBOL_GPL(save_stack_trace); |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 60 | |
Masami Hiramatsu | 3958106 | 2011-06-08 16:09:21 +0900 | [diff] [blame] | 61 | void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace) |
Vegard Nossum | acc6be5 | 2008-05-20 11:15:43 +0200 | [diff] [blame] | 62 | { |
Josh Poimboeuf | 49a612c | 2016-09-16 14:18:14 -0500 | [diff] [blame] | 63 | __save_stack_trace(trace, current, regs, false); |
Vegard Nossum | acc6be5 | 2008-05-20 11:15:43 +0200 | [diff] [blame] | 64 | } |
| 65 | |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 66 | void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) |
| 67 | { |
Andy Lutomirski | 1959a60 | 2016-09-15 22:45:45 -0700 | [diff] [blame] | 68 | if (!try_get_task_stack(tsk)) |
| 69 | return; |
| 70 | |
Josh Poimboeuf | 49a612c | 2016-09-16 14:18:14 -0500 | [diff] [blame] | 71 | __save_stack_trace(trace, tsk, NULL, true); |
Andy Lutomirski | 1959a60 | 2016-09-15 22:45:45 -0700 | [diff] [blame] | 72 | |
| 73 | put_task_stack(tsk); |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 74 | } |
Ingo Molnar | 8594698 | 2008-06-27 21:20:17 +0200 | [diff] [blame] | 75 | EXPORT_SYMBOL_GPL(save_stack_trace_tsk); |
Török Edwin | 02b6751 | 2008-11-22 13:28:47 +0200 | [diff] [blame] | 76 | |
| 77 | /* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */ |
| 78 | |
Frederic Weisbecker | c9cf4db | 2010-05-19 21:35:17 +0200 | [diff] [blame] | 79 | struct stack_frame_user { |
Török Edwin | 02b6751 | 2008-11-22 13:28:47 +0200 | [diff] [blame] | 80 | const void __user *next_fp; |
Török Edwin | 8d7c6a9 | 2008-11-23 12:39:06 +0200 | [diff] [blame] | 81 | unsigned long ret_addr; |
Török Edwin | 02b6751 | 2008-11-22 13:28:47 +0200 | [diff] [blame] | 82 | }; |
| 83 | |
Frederic Weisbecker | c9cf4db | 2010-05-19 21:35:17 +0200 | [diff] [blame] | 84 | static int |
| 85 | copy_stack_frame(const void __user *fp, struct stack_frame_user *frame) |
Török Edwin | 02b6751 | 2008-11-22 13:28:47 +0200 | [diff] [blame] | 86 | { |
| 87 | int ret; |
| 88 | |
| 89 | if (!access_ok(VERIFY_READ, fp, sizeof(*frame))) |
| 90 | return 0; |
| 91 | |
| 92 | ret = 1; |
| 93 | pagefault_disable(); |
| 94 | if (__copy_from_user_inatomic(frame, fp, sizeof(*frame))) |
| 95 | ret = 0; |
| 96 | pagefault_enable(); |
| 97 | |
| 98 | return ret; |
| 99 | } |
| 100 | |
Török Edwin | 8d7c6a9 | 2008-11-23 12:39:06 +0200 | [diff] [blame] | 101 | static inline void __save_stack_trace_user(struct stack_trace *trace) |
| 102 | { |
| 103 | const struct pt_regs *regs = task_pt_regs(current); |
| 104 | const void __user *fp = (const void __user *)regs->bp; |
| 105 | |
| 106 | if (trace->nr_entries < trace->max_entries) |
| 107 | trace->entries[trace->nr_entries++] = regs->ip; |
| 108 | |
| 109 | while (trace->nr_entries < trace->max_entries) { |
Frederic Weisbecker | c9cf4db | 2010-05-19 21:35:17 +0200 | [diff] [blame] | 110 | struct stack_frame_user frame; |
Török Edwin | 8d7c6a9 | 2008-11-23 12:39:06 +0200 | [diff] [blame] | 111 | |
| 112 | frame.next_fp = NULL; |
| 113 | frame.ret_addr = 0; |
| 114 | if (!copy_stack_frame(fp, &frame)) |
| 115 | break; |
| 116 | if ((unsigned long)fp < regs->sp) |
| 117 | break; |
| 118 | if (frame.ret_addr) { |
| 119 | trace->entries[trace->nr_entries++] = |
| 120 | frame.ret_addr; |
| 121 | } |
| 122 | if (fp == frame.next_fp) |
| 123 | break; |
| 124 | fp = frame.next_fp; |
| 125 | } |
| 126 | } |
| 127 | |
Török Edwin | 02b6751 | 2008-11-22 13:28:47 +0200 | [diff] [blame] | 128 | void save_stack_trace_user(struct stack_trace *trace) |
| 129 | { |
| 130 | /* |
| 131 | * Trace user stack if we are not a kernel thread |
| 132 | */ |
| 133 | if (current->mm) { |
Török Edwin | 8d7c6a9 | 2008-11-23 12:39:06 +0200 | [diff] [blame] | 134 | __save_stack_trace_user(trace); |
Török Edwin | 02b6751 | 2008-11-22 13:28:47 +0200 | [diff] [blame] | 135 | } |
| 136 | if (trace->nr_entries < trace->max_entries) |
| 137 | trace->entries[trace->nr_entries++] = ULONG_MAX; |
| 138 | } |
| 139 | |