--- /dev/null
+/* 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, g_needs_hwcap2_workaround;
+
+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);
+ g_needs_hwcap2_workaround = hwcap2 != 0;
+ }
+
+ 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; }
+
+int CRYPTO_needs_hwcap2_workaround(void) { return g_needs_hwcap2_workaround; }
+
+#endif // OPENSSL_ARM && !OPENSSL_STATIC_ARMCAP
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