Move ARM cpuinfo functions to the header.
ClusterFuzz folks want to switch to a shared library build, so call into
these another way. The new setup isn't quite ideal because the real code
builds as C and now tests as C++, but it should work.
Bug: chromium:907115
Change-Id: Ia1ffc18832739b09fee21b84ee5d181e61feaa15
Reviewed-on: https://boringssl-review.googlesource.com/c/33285
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/crypto/cpu-arm-linux.h b/crypto/cpu-arm-linux.h
index eabf4ea..e326285 100644
--- a/crypto/cpu-arm-linux.h
+++ b/crypto/cpu-arm-linux.h
@@ -17,14 +17,17 @@
#include <openssl/base.h>
+#include <string.h>
+
+#include "internal.h"
+
#if defined(__cplusplus)
extern "C" {
#endif
-// The following symbols are defined on all platforms and exported for testing
-// and fuzzing purposes. They are not exported from the shared library so the
-// static linker will drop them outside of tests.
+// 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)
@@ -40,17 +43,156 @@
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|.
-unsigned long crypto_get_arm_hwcap_from_cpuinfo(const STRING_PIECE *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|.
-unsigned long crypto_get_arm_hwcap2_from_cpuinfo(const STRING_PIECE *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.
-int crypto_cpuinfo_has_broken_neon(const STRING_PIECE *cpuinfo);
+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
