xref: /openbsd-src/lib/libcrypto/arch/arm/armcap.c (revision f681f7ca6f2943f05a6045dea4ea2328849bd5e7)
1 /* $OpenBSD: armcap.c,v 1.3 2024/08/29 03:30:05 deraadt Exp $ */
2 #include <stdio.h>
3 #include <stdlib.h>
4 #include <string.h>
5 #include <setjmp.h>
6 #include <signal.h>
7 #include <openssl/crypto.h>
8 
9 #include "arm_arch.h"
10 
11 unsigned int OPENSSL_armcap_P;
12 
13 #if __ARM_ARCH__ >= 7
14 static sigset_t all_masked;
15 
16 static sigjmp_buf ill_jmp;
17 
18 static void
19 ill_handler(int sig)
20 {
21 	siglongjmp(ill_jmp, sig);
22 }
23 
24 /*
25  * Following subroutines could have been inlined, but it's not all
26  * ARM compilers support inline assembler...
27  */
28 void _armv7_neon_probe(void);
29 void _armv8_aes_probe(void);
30 void _armv8_sha1_probe(void);
31 void _armv8_sha256_probe(void);
32 void _armv8_pmull_probe(void);
33 #endif
34 
35 void
36 OPENSSL_cpuid_setup(void)
37 {
38 #if __ARM_ARCH__ >= 7
39 	struct sigaction	ill_oact, ill_act;
40 	sigset_t		oset;
41 #endif
42 	static int trigger = 0;
43 
44 	if (trigger)
45 		return;
46 	trigger = 1;
47 
48 	OPENSSL_armcap_P = 0;
49 
50 #if __ARM_ARCH__ >= 7
51 	sigfillset(&all_masked);
52 	sigdelset(&all_masked, SIGILL);
53 	sigdelset(&all_masked, SIGTRAP);
54 	sigdelset(&all_masked, SIGFPE);
55 	sigdelset(&all_masked, SIGBUS);
56 	sigdelset(&all_masked, SIGSEGV);
57 
58 	memset(&ill_act, 0, sizeof(ill_act));
59 	ill_act.sa_handler = ill_handler;
60 	ill_act.sa_mask = all_masked;
61 
62 	sigprocmask(SIG_SETMASK, &ill_act.sa_mask, &oset);
63 	sigaction(SIGILL, &ill_act, &ill_oact);
64 
65 	if (sigsetjmp(ill_jmp, 1) == 0) {
66 		_armv7_neon_probe();
67 		OPENSSL_armcap_P |= ARMV7_NEON;
68 		if (sigsetjmp(ill_jmp, 1) == 0) {
69 			_armv8_pmull_probe();
70 			OPENSSL_armcap_P |= ARMV8_PMULL | ARMV8_AES;
71 		} else if (sigsetjmp(ill_jmp, 1) == 0) {
72 			_armv8_aes_probe();
73 			OPENSSL_armcap_P |= ARMV8_AES;
74 		}
75 		if (sigsetjmp(ill_jmp, 1) == 0) {
76 			_armv8_sha1_probe();
77 			OPENSSL_armcap_P |= ARMV8_SHA1;
78 		}
79 		if (sigsetjmp(ill_jmp, 1) == 0) {
80 			_armv8_sha256_probe();
81 			OPENSSL_armcap_P |= ARMV8_SHA256;
82 		}
83 	}
84 
85 	sigaction (SIGILL, &ill_oact, NULL);
86 	sigprocmask(SIG_SETMASK, &oset, NULL);
87 #endif
88 }
89