1 | /* |
2 | * Copyright (c) 2016 Apple Computer, Inc. All rights reserved. |
3 | * |
4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
5 | * |
6 | * This file contains Original Code and/or Modifications of Original Code |
7 | * as defined in and that are subject to the Apple Public Source License |
8 | * Version 2.0 (the 'License'). You may not use this file except in |
9 | * compliance with the License. The rights granted to you under the License |
10 | * may not be used to create, or enable the creation or redistribution of, |
11 | * unlawful or unlicensed copies of an Apple operating system, or to |
12 | * circumvent, violate, or enable the circumvention or violation of, any |
13 | * terms of an Apple operating system software license agreement. |
14 | * |
15 | * Please obtain a copy of the License at |
16 | * http://www.opensource.apple.com/apsl/ and read it before using this file. |
17 | * |
18 | * The Original Code and all software distributed under the License are |
19 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
21 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
22 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
23 | * Please see the License for the specific language governing rights and |
24 | * limitations under the License. |
25 | * |
26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
27 | */ |
28 | |
29 | #include <kern/backtrace.h> |
30 | #include <kern/kalloc.h> |
31 | #include <sys/errno.h> |
32 | #include <sys/sysctl.h> |
33 | #include <sys/systm.h> |
34 | |
35 | #define MAX_BACKTRACE (128) |
36 | |
37 | #define BACKTRACE_USER (0) |
38 | |
39 | static int backtrace_sysctl SYSCTL_HANDLER_ARGS; |
40 | |
41 | SYSCTL_NODE(_kern, OID_AUTO, backtrace, CTLFLAG_RW | CTLFLAG_LOCKED, 0, |
42 | "backtrace" ); |
43 | |
44 | SYSCTL_PROC(_kern_backtrace, OID_AUTO, user, |
45 | CTLFLAG_RW | CTLFLAG_LOCKED, (void *)BACKTRACE_USER, |
46 | sizeof(uint64_t), backtrace_sysctl, "O" , "take user backtrace of current thread" ); |
47 | |
48 | static int |
49 | backtrace_sysctl SYSCTL_HANDLER_ARGS |
50 | { |
51 | #pragma unused(oidp, arg2) |
52 | uintptr_t *bt; |
53 | uint32_t bt_len, bt_filled; |
54 | uintptr_t type = (uintptr_t)arg1; |
55 | bool user_64; |
56 | int err = 0; |
57 | |
58 | if (type != BACKTRACE_USER) { |
59 | return EINVAL; |
60 | } |
61 | |
62 | if (req->oldptr == USER_ADDR_NULL || req->oldlen == 0) { |
63 | return EFAULT; |
64 | } |
65 | |
66 | bt_len = req->oldlen > MAX_BACKTRACE ? MAX_BACKTRACE : req->oldlen; |
67 | bt = kalloc(sizeof(uintptr_t) * bt_len); |
68 | if (!bt) { |
69 | return ENOBUFS; |
70 | } |
71 | bzero(bt, sizeof(uintptr_t) * bt_len); |
72 | err = backtrace_user(bt, bt_len, &bt_filled, &user_64); |
73 | if (err) { |
74 | goto out; |
75 | } |
76 | |
77 | err = copyout(bt, req->oldptr, bt_filled * sizeof(uint64_t)); |
78 | if (err) { |
79 | goto out; |
80 | } |
81 | req->oldidx = bt_filled; |
82 | |
83 | out: |
84 | kfree(bt, sizeof(uintptr_t) * bt_len); |
85 | return err; |
86 | } |
87 | |