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authorDavid Benjamin <davidben@google.com>2016-04-28 12:17:55 -0400
committerDavid Benjamin <davidben@google.com>2016-04-29 14:24:33 -0400
commit1b5bcb59f40993de836e40bf4190f6ac6fbc9309 (patch)
treee1c8a4a4873b5d1269f068bd826a39fb4b1e4651
parentb69307a1c4e99284c7c014bcfa7a5bee8dbb433f (diff)
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Make CRYPTO_is_NEON_capable aware of the buggy CPU.chromium-2704
If we're to allow the buggy CPU workaround to fire when __ARM_NEON__ is set, CRYPTO_is_NEON_capable also needs to be aware of it. Also add an API to export this value out of BoringSSL, so we can get some metrics on how prevalent this chip is. BUG=chromium:606629 Change-Id: I97d65a47a6130689098b32ce45a8c57c468aa405 Reviewed-on: https://boringssl-review.googlesource.com/7796 Reviewed-by: Adam Langley <agl@google.com>
-rw-r--r--crypto/cpu-arm-linux.c7
-rw-r--r--include/openssl/cpu.h15
2 files changed, 19 insertions, 3 deletions
diff --git a/crypto/cpu-arm-linux.c b/crypto/cpu-arm-linux.c
index ab4648c..73c38ec 100644
--- a/crypto/cpu-arm-linux.c
+++ b/crypto/cpu-arm-linux.c
@@ -288,6 +288,8 @@ static int has_broken_neon(const STRING_PIECE *cpuinfo) {
extern uint32_t OPENSSL_armcap_P;
+static int g_has_broken_neon;
+
void OPENSSL_cpuid_setup(void) {
char *cpuinfo_data;
size_t cpuinfo_len;
@@ -317,7 +319,8 @@ void OPENSSL_cpuid_setup(void) {
}
/* Clear NEON support if known broken. */
- if (has_broken_neon(&cpuinfo)) {
+ g_has_broken_neon = has_broken_neon(&cpuinfo);
+ if (g_has_broken_neon) {
hwcap &= ~HWCAP_NEON;
}
@@ -352,4 +355,6 @@ void OPENSSL_cpuid_setup(void) {
OPENSSL_free(cpuinfo_data);
}
+int CRYPTO_has_broken_NEON(void) { return g_has_broken_neon; }
+
#endif /* OPENSSL_ARM && !OPENSSL_STATIC_ARMCAP */
diff --git a/include/openssl/cpu.h b/include/openssl/cpu.h
index dad544e..55be4c1 100644
--- a/include/openssl/cpu.h
+++ b/include/openssl/cpu.h
@@ -110,13 +110,24 @@ OPENSSL_EXPORT char CRYPTO_is_NEON_capable_at_runtime(void);
/* CRYPTO_is_NEON_capable returns true if the current CPU has a NEON unit. If
* this is known statically then it returns one immediately. */
static inline int CRYPTO_is_NEON_capable(void) {
-#if defined(__ARM_NEON__)
+ /* Only statically skip the runtime lookup on aarch64. On arm, one CPU is
+ * known to have a broken NEON unit which is known to fail with on some
+ * hand-written NEON assembly. For now, continue to apply the workaround even
+ * when the compiler is instructed to freely emit NEON code. See
+ * https://crbug.com/341598 and https://crbug.com/606629. */
+#if defined(__ARM_NEON__) && !defined(OPENSSL_ARM)
return 1;
#else
return CRYPTO_is_NEON_capable_at_runtime();
#endif
}
+#if defined(OPENSSL_ARM)
+/* CRYPTO_has_broken_NEON returns one if the current CPU is known to have a
+ * broken NEON unit. See https://crbug.com/341598. */
+OPENSSL_EXPORT int CRYPTO_has_broken_NEON(void);
+#endif
+
/* CRYPTO_is_ARMv8_AES_capable returns true if the current CPU supports the
* ARMv8 AES instruction. */
int CRYPTO_is_ARMv8_AES_capable(void);
@@ -152,7 +163,7 @@ static inline int CRYPTO_is_ARMv8_PMULL_capable(void) {
}
#endif /* OPENSSL_STATIC_ARMCAP */
-#endif /* OPENSSL_ARM */
+#endif /* OPENSSL_ARM || OPENSSL_AARCH64 */
#if defined(__cplusplus)