armcap.c revision 325334 
1#include <stdio.h>
2#include <stdlib.h>
3#include <string.h>
4#include <setjmp.h>
5#include <signal.h>
6#include <crypto.h>
7
8#include "arm_arch.h"
9
10__attribute__ ((visibility("hidden")))
11unsigned int OPENSSL_armcap_P = 0;
12
13#if __ARM_MAX_ARCH__<7
14void OPENSSL_cpuid_setup(void)
15{
16}
17
18unsigned long OPENSSL_rdtsc(void)
19{
20    return 0;
21}
22#else
23static sigset_t all_masked;
24
25static sigjmp_buf ill_jmp;
26static void ill_handler(int sig)
27{
28    siglongjmp(ill_jmp, sig);
29}
30
31/*
32 * Following subroutines could have been inlined, but it's not all
33 * ARM compilers support inline assembler...
34 */
35void _armv7_neon_probe(void);
36void _armv8_aes_probe(void);
37void _armv8_sha1_probe(void);
38void _armv8_sha256_probe(void);
39void _armv8_pmull_probe(void);
40unsigned long _armv7_tick(void);
41
42unsigned long OPENSSL_rdtsc(void)
43{
44    if (OPENSSL_armcap_P & ARMV7_TICK)
45        return _armv7_tick();
46    else
47        return 0;
48}
49
50/*
51 * Use a weak reference to getauxval() so we can use it if it is available but
52 * don't break the build if it is not.
53 */
54# if defined(__GNUC__) && __GNUC__>=2
55void OPENSSL_cpuid_setup(void) __attribute__ ((constructor));
56extern unsigned long getauxval(unsigned long type) __attribute__ ((weak));
57# else
58static unsigned long (*getauxval) (unsigned long) = NULL;
59# endif
60
61/*
62 * ARM puts the the feature bits for Crypto Extensions in AT_HWCAP2, whereas
63 * AArch64 used AT_HWCAP.
64 */
65# if defined(__arm__) || defined (__arm)
66#  define HWCAP                  16
67                                  /* AT_HWCAP */
68#  define HWCAP_NEON             (1 << 12)
69
70#  define HWCAP_CE               26
71                                  /* AT_HWCAP2 */
72#  define HWCAP_CE_AES           (1 << 0)
73#  define HWCAP_CE_PMULL         (1 << 1)
74#  define HWCAP_CE_SHA1          (1 << 2)
75#  define HWCAP_CE_SHA256        (1 << 3)
76# elif defined(__aarch64__)
77#  define HWCAP                  16
78                                  /* AT_HWCAP */
79#  define HWCAP_NEON             (1 << 1)
80
81#  define HWCAP_CE               HWCAP
82#  define HWCAP_CE_AES           (1 << 3)
83#  define HWCAP_CE_PMULL         (1 << 4)
84#  define HWCAP_CE_SHA1          (1 << 5)
85#  define HWCAP_CE_SHA256        (1 << 6)
86# endif
87
88void OPENSSL_cpuid_setup(void)
89{
90    char *e;
91    struct sigaction ill_oact, ill_act;
92    sigset_t oset;
93    static int trigger = 0;
94
95    if (trigger)
96        return;
97    trigger = 1;
98
99    if ((e = getenv("OPENSSL_armcap"))) {
100        OPENSSL_armcap_P = (unsigned int)strtoul(e, NULL, 0);
101        return;
102    }
103
104    sigfillset(&all_masked);
105    sigdelset(&all_masked, SIGILL);
106    sigdelset(&all_masked, SIGTRAP);
107    sigdelset(&all_masked, SIGFPE);
108    sigdelset(&all_masked, SIGBUS);
109    sigdelset(&all_masked, SIGSEGV);
110
111    OPENSSL_armcap_P = 0;
112
113    memset(&ill_act, 0, sizeof(ill_act));
114    ill_act.sa_handler = ill_handler;
115    ill_act.sa_mask = all_masked;
116
117    sigprocmask(SIG_SETMASK, &ill_act.sa_mask, &oset);
118    sigaction(SIGILL, &ill_act, &ill_oact);
119
120    if (getauxval != NULL) {
121        if (getauxval(HWCAP) & HWCAP_NEON) {
122            unsigned long hwcap = getauxval(HWCAP_CE);
123
124            OPENSSL_armcap_P |= ARMV7_NEON;
125
126            if (hwcap & HWCAP_CE_AES)
127                OPENSSL_armcap_P |= ARMV8_AES;
128
129            if (hwcap & HWCAP_CE_PMULL)
130                OPENSSL_armcap_P |= ARMV8_PMULL;
131
132            if (hwcap & HWCAP_CE_SHA1)
133                OPENSSL_armcap_P |= ARMV8_SHA1;
134
135            if (hwcap & HWCAP_CE_SHA256)
136                OPENSSL_armcap_P |= ARMV8_SHA256;
137        }
138    } else if (sigsetjmp(ill_jmp, 1) == 0) {
139        _armv7_neon_probe();
140        OPENSSL_armcap_P |= ARMV7_NEON;
141        if (sigsetjmp(ill_jmp, 1) == 0) {
142            _armv8_pmull_probe();
143            OPENSSL_armcap_P |= ARMV8_PMULL | ARMV8_AES;
144        } else if (sigsetjmp(ill_jmp, 1) == 0) {
145            _armv8_aes_probe();
146            OPENSSL_armcap_P |= ARMV8_AES;
147        }
148        if (sigsetjmp(ill_jmp, 1) == 0) {
149            _armv8_sha1_probe();
150            OPENSSL_armcap_P |= ARMV8_SHA1;
151        }
152        if (sigsetjmp(ill_jmp, 1) == 0) {
153            _armv8_sha256_probe();
154            OPENSSL_armcap_P |= ARMV8_SHA256;
155        }
156    }
157    if (sigsetjmp(ill_jmp, 1) == 0) {
158        _armv7_tick();
159        OPENSSL_armcap_P |= ARMV7_TICK;
160    }
161
162    sigaction(SIGILL, &ill_oact, NULL);
163    sigprocmask(SIG_SETMASK, &oset, NULL);
164}
165#endif
166