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- /* Copyright (c) 2018, 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. */
-
- #ifndef OPENSSL_HEADER_CRYPTO_CPU_ARM_LINUX_H
- #define OPENSSL_HEADER_CRYPTO_CPU_ARM_LINUX_H
-
- #include <openssl/base.h>
-
- #include <string.h>
-
- #include "internal.h"
-
- #if defined(__cplusplus)
- extern "C" {
- #endif
-
-
- // The cpuinfo parser lives in a header file so it may be accessible from
- // cross-platform fuzzers without adding code to those platforms normally.
-
- #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)
-
- 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 = (const char *)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_get_delimited reads a |sep|-delimited entry from |s|, writing it
- // to |out| and updating |s| to point beyond it. It returns one on success and
- // zero if |s| is empty. If |s| is has no copies of |sep| and is non-empty, it
- // reads the entire string to |out|.
- static int STRING_PIECE_get_delimited(STRING_PIECE *s, STRING_PIECE *out, char sep) {
- if (s->len == 0) {
- return 0;
- }
- if (!STRING_PIECE_split(out, s, s, sep)) {
- // |s| had no instances of |sep|. Return the entire string.
- *out = *s;
- s->data += s->len;
- s->len = 0;
- }
- 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_get_delimited(&remaining, &line, '\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_get_delimited(&remaining, &feature, ' ')) {
- if (STRING_PIECE_equals(&feature, item)) {
- return 1;
- }
- }
- return 0;
- }
-
- // crypto_get_arm_hwcap_from_cpuinfo returns an equivalent ARM |AT_HWCAP| value
- // from |cpuinfo|.
- static unsigned long crypto_get_arm_hwcap_from_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;
- }
-
- // crypto_get_arm_hwcap2_from_cpuinfo returns an equivalent ARM |AT_HWCAP2|
- // value from |cpuinfo|.
- static unsigned long crypto_get_arm_hwcap2_from_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;
- }
-
- // crypto_cpuinfo_has_broken_neon returns one if |cpuinfo| matches a CPU known
- // to have broken NEON unit and zero otherwise. See https://crbug.com/341598.
- static int crypto_cpuinfo_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");
- }
-
-
- #if defined(__cplusplus)
- } // extern C
- #endif
-
- #endif // OPENSSL_HEADER_CRYPTO_CPU_ARM_LINUX_H
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