1*1031c584SApple OSS Distributions /*
2*1031c584SApple OSS Distributions * Copyright (c) 2021 Apple Inc. All rights reserved.
3*1031c584SApple OSS Distributions *
4*1031c584SApple OSS Distributions * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*1031c584SApple OSS Distributions *
6*1031c584SApple OSS Distributions * This file contains Original Code and/or Modifications of Original Code
7*1031c584SApple OSS Distributions * as defined in and that are subject to the Apple Public Source License
8*1031c584SApple OSS Distributions * Version 2.0 (the 'License'). You may not use this file except in
9*1031c584SApple OSS Distributions * compliance with the License. The rights granted to you under the License
10*1031c584SApple OSS Distributions * may not be used to create, or enable the creation or redistribution of,
11*1031c584SApple OSS Distributions * unlawful or unlicensed copies of an Apple operating system, or to
12*1031c584SApple OSS Distributions * circumvent, violate, or enable the circumvention or violation of, any
13*1031c584SApple OSS Distributions * terms of an Apple operating system software license agreement.
14*1031c584SApple OSS Distributions *
15*1031c584SApple OSS Distributions * Please obtain a copy of the License at
16*1031c584SApple OSS Distributions * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*1031c584SApple OSS Distributions *
18*1031c584SApple OSS Distributions * The Original Code and all software distributed under the License are
19*1031c584SApple OSS Distributions * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20*1031c584SApple OSS Distributions * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21*1031c584SApple OSS Distributions * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22*1031c584SApple OSS Distributions * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23*1031c584SApple OSS Distributions * Please see the License for the specific language governing rights and
24*1031c584SApple OSS Distributions * limitations under the License.
25*1031c584SApple OSS Distributions *
26*1031c584SApple OSS Distributions * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*1031c584SApple OSS Distributions */
28*1031c584SApple OSS Distributions
29*1031c584SApple OSS Distributions #if (DEVELOPMENT || DEBUG) && !KASAN
30*1031c584SApple OSS Distributions
31*1031c584SApple OSS Distributions #include <sys/sysctl.h>
32*1031c584SApple OSS Distributions #include <libkern/stack_protector.h>
33*1031c584SApple OSS Distributions
34*1031c584SApple OSS Distributions __attribute__((noinline))
35*1031c584SApple OSS Distributions static int
check_for_cookie(const char * str,size_t len)36*1031c584SApple OSS Distributions check_for_cookie(const char *str, size_t len)
37*1031c584SApple OSS Distributions {
38*1031c584SApple OSS Distributions long buf[4];
39*1031c584SApple OSS Distributions long *search = (long *)(void *)&buf[0];
40*1031c584SApple OSS Distributions size_t n;
41*1031c584SApple OSS Distributions
42*1031c584SApple OSS Distributions assert(len < sizeof(buf));
43*1031c584SApple OSS Distributions assert(__stack_chk_guard != 0);
44*1031c584SApple OSS Distributions assert(((uintptr_t)search & (sizeof(long) - 1)) == 0);
45*1031c584SApple OSS Distributions
46*1031c584SApple OSS Distributions /* force compiler to insert stack cookie check: */
47*1031c584SApple OSS Distributions memcpy(buf, str, len);
48*1031c584SApple OSS Distributions
49*1031c584SApple OSS Distributions /* 32 x sizeof(long) should be plenty to find the cookie: */
50*1031c584SApple OSS Distributions for (n = 0; n < 32; ++n) {
51*1031c584SApple OSS Distributions if (*(search++) == __stack_chk_guard) {
52*1031c584SApple OSS Distributions return 0;
53*1031c584SApple OSS Distributions }
54*1031c584SApple OSS Distributions }
55*1031c584SApple OSS Distributions
56*1031c584SApple OSS Distributions return ESRCH;
57*1031c584SApple OSS Distributions }
58*1031c584SApple OSS Distributions
59*1031c584SApple OSS Distributions static int
60*1031c584SApple OSS Distributions sysctl_run_stack_chk_tests SYSCTL_HANDLER_ARGS
61*1031c584SApple OSS Distributions {
62*1031c584SApple OSS Distributions #pragma unused(arg1, arg2, oidp)
63*1031c584SApple OSS Distributions
64*1031c584SApple OSS Distributions unsigned int dummy = 0;
65*1031c584SApple OSS Distributions int error, changed = 0, kr;
66*1031c584SApple OSS Distributions error = sysctl_io_number(req, 0, sizeof(dummy), &dummy, &changed);
67*1031c584SApple OSS Distributions if (error || !changed) {
68*1031c584SApple OSS Distributions return error;
69*1031c584SApple OSS Distributions }
70*1031c584SApple OSS Distributions
71*1031c584SApple OSS Distributions kr = check_for_cookie("foo", 3);
72*1031c584SApple OSS Distributions return kr;
73*1031c584SApple OSS Distributions }
74*1031c584SApple OSS Distributions
75*1031c584SApple OSS Distributions SYSCTL_PROC(_kern, OID_AUTO, run_stack_chk_tests,
76*1031c584SApple OSS Distributions CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_MASKED,
77*1031c584SApple OSS Distributions 0, 0, sysctl_run_stack_chk_tests, "I", "");
78*1031c584SApple OSS Distributions
79*1031c584SApple OSS Distributions #endif /* (DEVELOPMENT || DEBUG) && !KASAN */
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