| /* Copyright (c) 2016, Google Inc. |
| * |
| * Permission to use, copy, modify, and/or distribute this software for any |
| * purpose with or without fee is hereby granted, provided that the above |
| * copyright notice and this permission notice appear in all copies. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY |
| * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION |
| * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN |
| * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ |
| |
| #include <openssl/cpu.h> |
| |
| #if defined(OPENSSL_ARM) && !defined(OPENSSL_STATIC_ARMCAP) |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <string.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| #include <openssl/arm_arch.h> |
| #include <openssl/buf.h> |
| #include <openssl/mem.h> |
| |
| #include "internal.h" |
| |
| |
| #define AT_HWCAP 16 |
| #define AT_HWCAP2 26 |
| |
| #define HWCAP_NEON (1 << 12) |
| |
| // See /usr/include/asm/hwcap.h on an ARM installation for the source of |
| // these values. |
| #define HWCAP2_AES (1 << 0) |
| #define HWCAP2_PMULL (1 << 1) |
| #define HWCAP2_SHA1 (1 << 2) |
| #define HWCAP2_SHA2 (1 << 3) |
| |
| // |getauxval| is not available on Android until API level 20. Link it as a weak |
| // symbol and use other methods as fallback. |
| unsigned long getauxval(unsigned long type) __attribute__((weak)); |
| |
| static int open_eintr(const char *path, int flags) { |
| int ret; |
| do { |
| ret = open(path, flags); |
| } while (ret < 0 && errno == EINTR); |
| return ret; |
| } |
| |
| static ssize_t read_eintr(int fd, void *out, size_t len) { |
| ssize_t ret; |
| do { |
| ret = read(fd, out, len); |
| } while (ret < 0 && errno == EINTR); |
| return ret; |
| } |
| |
| // read_full reads exactly |len| bytes from |fd| to |out|. On error or end of |
| // file, it returns zero. |
| static int read_full(int fd, void *out, size_t len) { |
| char *outp = out; |
| while (len > 0) { |
| ssize_t ret = read_eintr(fd, outp, len); |
| if (ret <= 0) { |
| return 0; |
| } |
| outp += ret; |
| len -= ret; |
| } |
| return 1; |
| } |
| |
| // read_file opens |path| and reads until end-of-file. On success, it returns |
| // one and sets |*out_ptr| and |*out_len| to a newly-allocated buffer with the |
| // contents. Otherwise, it returns zero. |
| static int read_file(char **out_ptr, size_t *out_len, const char *path) { |
| int fd = open_eintr(path, O_RDONLY); |
| if (fd < 0) { |
| return 0; |
| } |
| |
| static const size_t kReadSize = 1024; |
| int ret = 0; |
| size_t cap = kReadSize, len = 0; |
| char *buf = OPENSSL_malloc(cap); |
| if (buf == NULL) { |
| goto err; |
| } |
| |
| for (;;) { |
| if (cap - len < kReadSize) { |
| size_t new_cap = cap * 2; |
| if (new_cap < cap) { |
| goto err; |
| } |
| char *new_buf = OPENSSL_realloc(buf, new_cap); |
| if (new_buf == NULL) { |
| goto err; |
| } |
| buf = new_buf; |
| cap = new_cap; |
| } |
| |
| ssize_t bytes_read = read_eintr(fd, buf + len, kReadSize); |
| if (bytes_read < 0) { |
| goto err; |
| } |
| if (bytes_read == 0) { |
| break; |
| } |
| len += bytes_read; |
| } |
| |
| *out_ptr = buf; |
| *out_len = len; |
| ret = 1; |
| buf = NULL; |
| |
| err: |
| OPENSSL_free(buf); |
| close(fd); |
| return ret; |
| } |
| |
| // getauxval_proc behaves like |getauxval| but reads from /proc/self/auxv. |
| static unsigned long getauxval_proc(unsigned long type) { |
| int fd = open_eintr("/proc/self/auxv", O_RDONLY); |
| if (fd < 0) { |
| return 0; |
| } |
| |
| struct { |
| unsigned long tag; |
| unsigned long value; |
| } entry; |
| |
| for (;;) { |
| if (!read_full(fd, &entry, sizeof(entry)) || |
| (entry.tag == 0 && entry.value == 0)) { |
| break; |
| } |
| if (entry.tag == type) { |
| close(fd); |
| return entry.value; |
| } |
| } |
| close(fd); |
| return 0; |
| } |
| |
| typedef struct { |
| const char *data; |
| size_t len; |
| } STRING_PIECE; |
| |
| static int STRING_PIECE_equals(const STRING_PIECE *a, const char *b) { |
| size_t b_len = strlen(b); |
| return a->len == b_len && OPENSSL_memcmp(a->data, b, b_len) == 0; |
| } |
| |
| // STRING_PIECE_split finds the first occurence of |sep| in |in| and, if found, |
| // sets |*out_left| and |*out_right| to |in| split before and after it. It |
| // returns one if |sep| was found and zero otherwise. |
| static int STRING_PIECE_split(STRING_PIECE *out_left, STRING_PIECE *out_right, |
| const STRING_PIECE *in, char sep) { |
| const char *p = OPENSSL_memchr(in->data, sep, in->len); |
| if (p == NULL) { |
| return 0; |
| } |
| // |out_left| or |out_right| may alias |in|, so make a copy. |
| STRING_PIECE in_copy = *in; |
| out_left->data = in_copy.data; |
| out_left->len = p - in_copy.data; |
| out_right->data = in_copy.data + out_left->len + 1; |
| out_right->len = in_copy.len - out_left->len - 1; |
| return 1; |
| } |
| |
| // STRING_PIECE_trim removes leading and trailing whitespace from |s|. |
| static void STRING_PIECE_trim(STRING_PIECE *s) { |
| while (s->len != 0 && (s->data[0] == ' ' || s->data[0] == '\t')) { |
| s->data++; |
| s->len--; |
| } |
| while (s->len != 0 && |
| (s->data[s->len - 1] == ' ' || s->data[s->len - 1] == '\t')) { |
| s->len--; |
| } |
| } |
| |
| // extract_cpuinfo_field extracts a /proc/cpuinfo field named |field| from |
| // |in|. If found, it sets |*out| to the value and returns one. Otherwise, it |
| // returns zero. |
| static int extract_cpuinfo_field(STRING_PIECE *out, const STRING_PIECE *in, |
| const char *field) { |
| // Process |in| one line at a time. |
| STRING_PIECE remaining = *in, line; |
| while (STRING_PIECE_split(&line, &remaining, &remaining, '\n')) { |
| STRING_PIECE key, value; |
| if (!STRING_PIECE_split(&key, &value, &line, ':')) { |
| continue; |
| } |
| STRING_PIECE_trim(&key); |
| if (STRING_PIECE_equals(&key, field)) { |
| STRING_PIECE_trim(&value); |
| *out = value; |
| return 1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int cpuinfo_field_equals(const STRING_PIECE *cpuinfo, const char *field, |
| const char *value) { |
| STRING_PIECE extracted; |
| return extract_cpuinfo_field(&extracted, cpuinfo, field) && |
| STRING_PIECE_equals(&extracted, value); |
| } |
| |
| // has_list_item treats |list| as a space-separated list of items and returns |
| // one if |item| is contained in |list| and zero otherwise. |
| static int has_list_item(const STRING_PIECE *list, const char *item) { |
| STRING_PIECE remaining = *list, feature; |
| while (STRING_PIECE_split(&feature, &remaining, &remaining, ' ')) { |
| if (STRING_PIECE_equals(&feature, item)) { |
| return 1; |
| } |
| } |
| return 0; |
| } |
| |
| static unsigned long get_hwcap_cpuinfo(const STRING_PIECE *cpuinfo) { |
| if (cpuinfo_field_equals(cpuinfo, "CPU architecture", "8")) { |
| // This is a 32-bit ARM binary running on a 64-bit kernel. NEON is always |
| // available on ARMv8. Linux omits required features, so reading the |
| // "Features" line does not work. (For simplicity, use strict equality. We |
| // assume everything running on future ARM architectures will have a |
| // working |getauxval|.) |
| return HWCAP_NEON; |
| } |
| |
| STRING_PIECE features; |
| if (extract_cpuinfo_field(&features, cpuinfo, "Features") && |
| has_list_item(&features, "neon")) { |
| return HWCAP_NEON; |
| } |
| return 0; |
| } |
| |
| static unsigned long get_hwcap2_cpuinfo(const STRING_PIECE *cpuinfo) { |
| STRING_PIECE features; |
| if (!extract_cpuinfo_field(&features, cpuinfo, "Features")) { |
| return 0; |
| } |
| |
| unsigned long ret = 0; |
| if (has_list_item(&features, "aes")) { |
| ret |= HWCAP2_AES; |
| } |
| if (has_list_item(&features, "pmull")) { |
| ret |= HWCAP2_PMULL; |
| } |
| if (has_list_item(&features, "sha1")) { |
| ret |= HWCAP2_SHA1; |
| } |
| if (has_list_item(&features, "sha2")) { |
| ret |= HWCAP2_SHA2; |
| } |
| return ret; |
| } |
| |
| // has_broken_neon returns one if |in| matches a CPU known to have a broken |
| // NEON unit. See https://crbug.com/341598. |
| static int has_broken_neon(const STRING_PIECE *cpuinfo) { |
| return cpuinfo_field_equals(cpuinfo, "CPU implementer", "0x51") && |
| cpuinfo_field_equals(cpuinfo, "CPU architecture", "7") && |
| cpuinfo_field_equals(cpuinfo, "CPU variant", "0x1") && |
| cpuinfo_field_equals(cpuinfo, "CPU part", "0x04d") && |
| cpuinfo_field_equals(cpuinfo, "CPU revision", "0"); |
| } |
| |
| extern uint32_t OPENSSL_armcap_P; |
| |
| static int g_has_broken_neon; |
| |
| void OPENSSL_cpuid_setup(void) { |
| char *cpuinfo_data; |
| size_t cpuinfo_len; |
| if (!read_file(&cpuinfo_data, &cpuinfo_len, "/proc/cpuinfo")) { |
| return; |
| } |
| STRING_PIECE cpuinfo; |
| cpuinfo.data = cpuinfo_data; |
| cpuinfo.len = cpuinfo_len; |
| |
| // |getauxval| is not available on Android until API level 20. If it is |
| // unavailable, read from /proc/self/auxv as a fallback. This is unreadable |
| // on some versions of Android, so further fall back to /proc/cpuinfo. |
| // |
| // See |
| // https://android.googlesource.com/platform/ndk/+/882ac8f3392858991a0e1af33b4b7387ec856bd2 |
| // and b/13679666 (Google-internal) for details. |
| unsigned long hwcap = 0; |
| if (getauxval != NULL) { |
| hwcap = getauxval(AT_HWCAP); |
| } |
| if (hwcap == 0) { |
| hwcap = getauxval_proc(AT_HWCAP); |
| } |
| if (hwcap == 0) { |
| hwcap = get_hwcap_cpuinfo(&cpuinfo); |
| } |
| |
| // Clear NEON support if known broken. |
| g_has_broken_neon = has_broken_neon(&cpuinfo); |
| if (g_has_broken_neon) { |
| hwcap &= ~HWCAP_NEON; |
| } |
| |
| // Matching OpenSSL, only report other features if NEON is present. |
| if (hwcap & HWCAP_NEON) { |
| OPENSSL_armcap_P |= ARMV7_NEON; |
| |
| // Some ARMv8 Android devices don't expose AT_HWCAP2. Fall back to |
| // /proc/cpuinfo. See https://crbug.com/596156. |
| unsigned long hwcap2 = 0; |
| if (getauxval != NULL) { |
| hwcap2 = getauxval(AT_HWCAP2); |
| } |
| if (hwcap2 == 0) { |
| hwcap2 = get_hwcap2_cpuinfo(&cpuinfo); |
| } |
| |
| if (hwcap2 & HWCAP2_AES) { |
| OPENSSL_armcap_P |= ARMV8_AES; |
| } |
| if (hwcap2 & HWCAP2_PMULL) { |
| OPENSSL_armcap_P |= ARMV8_PMULL; |
| } |
| if (hwcap2 & HWCAP2_SHA1) { |
| OPENSSL_armcap_P |= ARMV8_SHA1; |
| } |
| if (hwcap2 & HWCAP2_SHA2) { |
| OPENSSL_armcap_P |= ARMV8_SHA256; |
| } |
| } |
| |
| OPENSSL_free(cpuinfo_data); |
| } |
| |
| int CRYPTO_has_broken_NEON(void) { return g_has_broken_neon; } |
| |
| #endif // OPENSSL_ARM && !OPENSSL_STATIC_ARMCAP |