1 // Copyright 2021 The BoringSSL Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include "internal.h"
16
17 #if defined(OPENSSL_AARCH64) && defined(OPENSSL_APPLE) && \
18 !defined(OPENSSL_STATIC_ARMCAP) && !defined(OPENSSL_NO_ASM)
19
20 #include <sys/sysctl.h>
21 #include <sys/types.h>
22
23
has_hw_feature(const char * name)24 static int has_hw_feature(const char *name) {
25 int value;
26 size_t len = sizeof(value);
27 if (sysctlbyname(name, &value, &len, NULL, 0) != 0) {
28 return 0;
29 }
30 if (len != sizeof(int)) {
31 // This should not happen. All the values queried should be integer-valued.
32 assert(0);
33 return 0;
34 }
35
36 // Per sys/sysctl.h:
37 //
38 // Selectors that return errors are not support on the system. Supported
39 // features will return 1 if they are recommended or 0 if they are supported
40 // but are not expected to help performance. Future versions of these
41 // selectors may return larger values as necessary so it is best to test for
42 // non zero.
43 return value != 0;
44 }
45
OPENSSL_cpuid_setup(void)46 void OPENSSL_cpuid_setup(void) {
47 // Apple ARM64 platforms have NEON and cryptography extensions available
48 // statically, so we do not need to query them. In particular, there sometimes
49 // are no sysctls corresponding to such features. See below.
50 #if !defined(__ARM_NEON) || !defined(__ARM_FEATURE_AES) || \
51 !defined(__ARM_FEATURE_SHA2)
52 #error "NEON and crypto extensions should be statically available."
53 #endif
54 OPENSSL_armcap_P =
55 ARMV7_NEON | ARMV8_AES | ARMV8_PMULL | ARMV8_SHA1 | ARMV8_SHA256;
56
57 // See Apple's documentation for sysctl names:
58 // https://developer.apple.com/documentation/kernel/1387446-sysctlbyname/determining_instruction_set_characteristics
59 //
60 // The new feature names, e.g. "hw.optional.arm.FEAT_SHA512", are only
61 // available in macOS 12. For compatibility with macOS 11, we also support
62 // the old names. The old names don't have values for features like FEAT_AES,
63 // so instead we detect them statically above.
64 //
65 // If querying new sysctls, update the Chromium sandbox definition. See
66 // https://crrev.com/c/4415225.
67 if (has_hw_feature("hw.optional.arm.FEAT_SHA512") ||
68 has_hw_feature("hw.optional.armv8_2_sha512")) {
69 OPENSSL_armcap_P |= ARMV8_SHA512;
70 }
71 }
72
73 #endif // OPENSSL_AARCH64 && OPENSSL_APPLE && !OPENSSL_STATIC_ARMCAP
74