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1 /* ====================================================================
2  * Copyright (c) 1998-2011 The OpenSSL Project.  All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in
13  *    the documentation and/or other materials provided with the
14  *    distribution.
15  *
16  * 3. All advertising materials mentioning features or use of this
17  *    software must display the following acknowledgment:
18  *    "This product includes software developed by the OpenSSL Project
19  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
20  *
21  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
22  *    endorse or promote products derived from this software without
23  *    prior written permission. For written permission, please contact
24  *    openssl-core@openssl.org.
25  *
26  * 5. Products derived from this software may not be called "OpenSSL"
27  *    nor may "OpenSSL" appear in their names without prior written
28  *    permission of the OpenSSL Project.
29  *
30  * 6. Redistributions of any form whatsoever must retain the following
31  *    acknowledgment:
32  *    "This product includes software developed by the OpenSSL Project
33  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
34  *
35  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
36  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
37  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
38  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
39  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
41  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
42  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
44  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
45  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
46  * OF THE POSSIBILITY OF SUCH DAMAGE.
47  * ====================================================================
48  *
49  * This product includes cryptographic software written by Eric Young
50  * (eay@cryptsoft.com).  This product includes software written by Tim
51  * Hudson (tjh@cryptsoft.com). */
52 
53 #ifndef OPENSSL_HEADER_ARM_ARCH_H
54 #define OPENSSL_HEADER_ARM_ARCH_H
55 
56 // arm_arch.h contains symbols used by ARM assembly, and the C code that calls
57 // it. It is included as a public header to simplify the build, but is not
58 // intended for external use.
59 
60 #if defined(__ARMEL__) || defined(_M_ARM) || defined(__AARCH64EL__) || \
61     defined(_M_ARM64)
62 
63 // ARMV7_NEON is true when a NEON unit is present in the current CPU.
64 #define ARMV7_NEON (1 << 0)
65 
66 // ARMV8_AES indicates support for hardware AES instructions.
67 #define ARMV8_AES (1 << 2)
68 
69 // ARMV8_SHA1 indicates support for hardware SHA-1 instructions.
70 #define ARMV8_SHA1 (1 << 3)
71 
72 // ARMV8_SHA256 indicates support for hardware SHA-256 instructions.
73 #define ARMV8_SHA256 (1 << 4)
74 
75 // ARMV8_PMULL indicates support for carryless multiplication.
76 #define ARMV8_PMULL (1 << 5)
77 
78 // ARMV8_SHA512 indicates support for hardware SHA-512 instructions.
79 #define ARMV8_SHA512 (1 << 6)
80 
81 #if defined(__ASSEMBLER__)
82 
83 // We require the ARM assembler provide |__ARM_ARCH| from Arm C Language
84 // Extensions (ACLE). This is supported in GCC 4.8+ and Clang 3.2+. MSVC does
85 // not implement ACLE, but we require Clang's assembler on Windows.
86 #if !defined(__ARM_ARCH)
87 #error "ARM assembler must define __ARM_ARCH"
88 #endif
89 
90 // __ARM_ARCH__ is used by OpenSSL assembly to determine the minimum target ARM
91 // version.
92 //
93 // TODO(davidben): Switch the assembly to use |__ARM_ARCH| directly.
94 #define __ARM_ARCH__ __ARM_ARCH
95 
96 // Even when building for 32-bit ARM, support for aarch64 crypto instructions
97 // will be included.
98 #define __ARM_MAX_ARCH__ 8
99 
100 // Support macros for
101 //   - Armv8.3-A Pointer Authentication and
102 //   - Armv8.5-A Branch Target Identification
103 // features which require emitting a .note.gnu.property section with the
104 // appropriate architecture-dependent feature bits set.
105 //
106 // |AARCH64_SIGN_LINK_REGISTER| and |AARCH64_VALIDATE_LINK_REGISTER| expand to
107 // PACIxSP and AUTIxSP, respectively. |AARCH64_SIGN_LINK_REGISTER| should be
108 // used immediately before saving the LR register (x30) to the stack.
109 // |AARCH64_VALIDATE_LINK_REGISTER| should be used immediately after restoring
110 // it. Note |AARCH64_SIGN_LINK_REGISTER|'s modifications to LR must be undone
111 // with |AARCH64_VALIDATE_LINK_REGISTER| before RET. The SP register must also
112 // have the same value at the two points. For example:
113 //
114 //   .global f
115 //   f:
116 //     AARCH64_SIGN_LINK_REGISTER
117 //     stp x29, x30, [sp, #-96]!
118 //     mov x29, sp
119 //     ...
120 //     ldp x29, x30, [sp], #96
121 //     AARCH64_VALIDATE_LINK_REGISTER
122 //     ret
123 //
124 // |AARCH64_VALID_CALL_TARGET| expands to BTI 'c'. Either it, or
125 // |AARCH64_SIGN_LINK_REGISTER|, must be used at every point that may be an
126 // indirect call target. In particular, all symbols exported from a file must
127 // begin with one of these macros. For example, a leaf function that does not
128 // save LR can instead use |AARCH64_VALID_CALL_TARGET|:
129 //
130 //   .globl return_zero
131 //   return_zero:
132 //     AARCH64_VALID_CALL_TARGET
133 //     mov x0, #0
134 //     ret
135 //
136 // A non-leaf function which does not immediately save LR may need both macros
137 // because |AARCH64_SIGN_LINK_REGISTER| appears late. For example, the function
138 // may jump to an alternate implementation before setting up the stack:
139 //
140 //   .globl with_early_jump
141 //   with_early_jump:
142 //     AARCH64_VALID_CALL_TARGET
143 //     cmp x0, #128
144 //     b.lt .Lwith_early_jump_128
145 //     AARCH64_SIGN_LINK_REGISTER
146 //     stp x29, x30, [sp, #-96]!
147 //     mov x29, sp
148 //     ...
149 //     ldp x29, x30, [sp], #96
150 //     AARCH64_VALIDATE_LINK_REGISTER
151 //     ret
152 //
153 //  .Lwith_early_jump_128:
154 //     ...
155 //     ret
156 //
157 // These annotations are only required with indirect calls. Private symbols that
158 // are only the target of direct calls do not require annotations. Also note
159 // that |AARCH64_VALID_CALL_TARGET| is only valid for indirect calls (BLR), not
160 // indirect jumps (BR). Indirect jumps in assembly are currently not supported
161 // and would require a macro for BTI 'j'.
162 //
163 // Although not necessary, it is safe to use these macros in 32-bit ARM
164 // assembly. This may be used to simplify dual 32-bit and 64-bit files.
165 //
166 // References:
167 // - "ELF for the Arm® 64-bit Architecture"
168 //   https://github.com/ARM-software/abi-aa/blob/master/aaelf64/aaelf64.rst
169 // - "Providing protection for complex software"
170 //   https://developer.arm.com/architectures/learn-the-architecture/providing-protection-for-complex-software
171 
172 #if defined(__ARM_FEATURE_BTI_DEFAULT) && __ARM_FEATURE_BTI_DEFAULT == 1
173 #define GNU_PROPERTY_AARCH64_BTI (1 << 0)   // Has Branch Target Identification
174 #define AARCH64_VALID_CALL_TARGET hint #34  // BTI 'c'
175 #else
176 #define GNU_PROPERTY_AARCH64_BTI 0  // No Branch Target Identification
177 #define AARCH64_VALID_CALL_TARGET
178 #endif
179 
180 #if defined(__ARM_FEATURE_PAC_DEFAULT) && \
181     (__ARM_FEATURE_PAC_DEFAULT & 1) == 1  // Signed with A-key
182 #define GNU_PROPERTY_AARCH64_POINTER_AUTH \
183   (1 << 1)                                       // Has Pointer Authentication
184 #define AARCH64_SIGN_LINK_REGISTER hint #25      // PACIASP
185 #define AARCH64_VALIDATE_LINK_REGISTER hint #29  // AUTIASP
186 #elif defined(__ARM_FEATURE_PAC_DEFAULT) && \
187     (__ARM_FEATURE_PAC_DEFAULT & 2) == 2  // Signed with B-key
188 #define GNU_PROPERTY_AARCH64_POINTER_AUTH \
189   (1 << 1)                                       // Has Pointer Authentication
190 #define AARCH64_SIGN_LINK_REGISTER hint #27      // PACIBSP
191 #define AARCH64_VALIDATE_LINK_REGISTER hint #31  // AUTIBSP
192 #else
193 #define GNU_PROPERTY_AARCH64_POINTER_AUTH 0  // No Pointer Authentication
194 #if GNU_PROPERTY_AARCH64_BTI != 0
195 #define AARCH64_SIGN_LINK_REGISTER AARCH64_VALID_CALL_TARGET
196 #else
197 #define AARCH64_SIGN_LINK_REGISTER
198 #endif
199 #define AARCH64_VALIDATE_LINK_REGISTER
200 #endif
201 
202 #if GNU_PROPERTY_AARCH64_POINTER_AUTH != 0 || GNU_PROPERTY_AARCH64_BTI != 0
203 .pushsection .note.gnu.property, "a";
204 .balign 8;
205 .long 4;
206 .long 0x10;
207 .long 0x5;
208 .asciz "GNU";
209 .long 0xc0000000; /* GNU_PROPERTY_AARCH64_FEATURE_1_AND */
210 .long 4;
211 .long (GNU_PROPERTY_AARCH64_POINTER_AUTH | GNU_PROPERTY_AARCH64_BTI);
212 .long 0;
213 .popsection;
214 #endif
215 
216 #endif  // __ASSEMBLER__
217 
218 #endif  // __ARMEL__ || _M_ARM || __AARCH64EL__ || _M_ARM64
219 
220 #endif  // OPENSSL_HEADER_ARM_ARCH_H
221