1*699cd480SApple OSS Distributions /*
2*699cd480SApple OSS Distributions * Copyright (c) 2021 Apple Inc. All rights reserved.
3*699cd480SApple OSS Distributions *
4*699cd480SApple OSS Distributions * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*699cd480SApple OSS Distributions *
6*699cd480SApple OSS Distributions * This file contains Original Code and/or Modifications of Original Code
7*699cd480SApple OSS Distributions * as defined in and that are subject to the Apple Public Source License
8*699cd480SApple OSS Distributions * Version 2.0 (the 'License'). You may not use this file except in
9*699cd480SApple OSS Distributions * compliance with the License. The rights granted to you under the License
10*699cd480SApple OSS Distributions * may not be used to create, or enable the creation or redistribution of,
11*699cd480SApple OSS Distributions * unlawful or unlicensed copies of an Apple operating system, or to
12*699cd480SApple OSS Distributions * circumvent, violate, or enable the circumvention or violation of, any
13*699cd480SApple OSS Distributions * terms of an Apple operating system software license agreement.
14*699cd480SApple OSS Distributions *
15*699cd480SApple OSS Distributions * Please obtain a copy of the License at
16*699cd480SApple OSS Distributions * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*699cd480SApple OSS Distributions *
18*699cd480SApple OSS Distributions * The Original Code and all software distributed under the License are
19*699cd480SApple OSS Distributions * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20*699cd480SApple OSS Distributions * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21*699cd480SApple OSS Distributions * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22*699cd480SApple OSS Distributions * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23*699cd480SApple OSS Distributions * Please see the License for the specific language governing rights and
24*699cd480SApple OSS Distributions * limitations under the License.
25*699cd480SApple OSS Distributions *
26*699cd480SApple OSS Distributions * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*699cd480SApple OSS Distributions */
28*699cd480SApple OSS Distributions
29*699cd480SApple OSS Distributions #if (DEVELOPMENT || DEBUG) && !KASAN
30*699cd480SApple OSS Distributions
31*699cd480SApple OSS Distributions #include <sys/sysctl.h>
32*699cd480SApple OSS Distributions #include <libkern/stack_protector.h>
33*699cd480SApple OSS Distributions
34*699cd480SApple OSS Distributions __attribute__((noinline))
35*699cd480SApple OSS Distributions static int
check_for_cookie(const char * str,size_t len)36*699cd480SApple OSS Distributions check_for_cookie(const char *str, size_t len)
37*699cd480SApple OSS Distributions {
38*699cd480SApple OSS Distributions long buf[4];
39*699cd480SApple OSS Distributions long *search = (long *)(void *)&buf[0];
40*699cd480SApple OSS Distributions size_t n;
41*699cd480SApple OSS Distributions
42*699cd480SApple OSS Distributions assert(len < sizeof(buf));
43*699cd480SApple OSS Distributions assert(__stack_chk_guard != 0);
44*699cd480SApple OSS Distributions assert(((uintptr_t)search & (sizeof(long) - 1)) == 0);
45*699cd480SApple OSS Distributions
46*699cd480SApple OSS Distributions /* force compiler to insert stack cookie check: */
47*699cd480SApple OSS Distributions memcpy(buf, str, len);
48*699cd480SApple OSS Distributions
49*699cd480SApple OSS Distributions /* 32 x sizeof(long) should be plenty to find the cookie: */
50*699cd480SApple OSS Distributions for (n = 0; n < 32; ++n) {
51*699cd480SApple OSS Distributions if (*(search++) == __stack_chk_guard) {
52*699cd480SApple OSS Distributions return 0;
53*699cd480SApple OSS Distributions }
54*699cd480SApple OSS Distributions }
55*699cd480SApple OSS Distributions
56*699cd480SApple OSS Distributions return ESRCH;
57*699cd480SApple OSS Distributions }
58*699cd480SApple OSS Distributions
59*699cd480SApple OSS Distributions static int
60*699cd480SApple OSS Distributions sysctl_run_stack_chk_tests SYSCTL_HANDLER_ARGS
61*699cd480SApple OSS Distributions {
62*699cd480SApple OSS Distributions #pragma unused(arg1, arg2, oidp)
63*699cd480SApple OSS Distributions
64*699cd480SApple OSS Distributions unsigned int dummy = 0;
65*699cd480SApple OSS Distributions int error, changed = 0, kr;
66*699cd480SApple OSS Distributions error = sysctl_io_number(req, 0, sizeof(dummy), &dummy, &changed);
67*699cd480SApple OSS Distributions if (error || !changed) {
68*699cd480SApple OSS Distributions return error;
69*699cd480SApple OSS Distributions }
70*699cd480SApple OSS Distributions
71*699cd480SApple OSS Distributions kr = check_for_cookie("foo", 3);
72*699cd480SApple OSS Distributions return kr;
73*699cd480SApple OSS Distributions }
74*699cd480SApple OSS Distributions
75*699cd480SApple OSS Distributions SYSCTL_PROC(_kern, OID_AUTO, run_stack_chk_tests,
76*699cd480SApple OSS Distributions CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_MASKED,
77*699cd480SApple OSS Distributions 0, 0, sysctl_run_stack_chk_tests, "I", "");
78*699cd480SApple OSS Distributions
79*699cd480SApple OSS Distributions #endif /* (DEVELOPMENT || DEBUG) && !KASAN */
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