Trim some redundant Arm feature detection files

cpu_arm_openbsd.c is the same as OPENSSL_STATIC_ARMCAP. cpu_aarch64_freebsd.c is the same as cpu_aarch64_sysreg.c. (The FreeBSD one was using the macros in their headers, but those macros expand to the same inline assembly.) Also send ANDROID_BAREMETAL + 32-bit Arm to OPENSSL_STATIC_ARMCAP. This way we can remove OPENSSL_STATIC_ARMCAP from the Android baremetal build without having to chase down constraining it to aarch64. See b/291106677#comment6 Update-Note: This is a slight change to the OpenBSD build. Previously, we assumed OpenBSD on 32-bit Arm implies NEON. Now, we pick it up from the __ARM_NEON define from ACLE, i.e. whether the compiler has been told that NEON is available. (This comes from -march or other options.) Doing that is desirable anyway: if NEON is in your baseline, you should tell your compiler so it can vectorize loops. Change-Id: Icd43a2b56bb6e3f04f0fed996ae750fba65e3312 Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/62066 Commit-Queue: David Benjamin <davidben@google.com> Reviewed-by: Bob Beck <bbe@google.com> (cherry picked from commit d95b03c315bac8c44d3ce062053d3a5817915d91)
aws · Jan 20, 2024 · d36bf85 · d36bf85
1 parent 5a4a7d1
commit d36bf85
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Showing 5 changed files with 13 additions and 126 deletions.
diff --git a/crypto/fipsmodule/bcm.c b/crypto/fipsmodule/bcm.c
@@ -74,10 +74,8 @@
 #include "cpucap/cpu_aarch64.c"
 #include "cpucap/cpu_aarch64_sysreg.c"
 #include "cpucap/cpu_aarch64_apple.c"
-#include "cpucap/cpu_aarch64_freebsd.c"
 #include "cpucap/cpu_aarch64_fuchsia.c"
 #include "cpucap/cpu_aarch64_linux.c"
-#include "cpucap/cpu_aarch64_openbsd.c"
 #include "cpucap/cpu_aarch64_win.c"
 #include "cpucap/cpu_arm_freebsd.c"
 #include "cpucap/cpu_arm_linux.c"

diff --git a/crypto/fipsmodule/cpucap/cpu_aarch64_freebsd.c b/crypto/fipsmodule/cpucap/cpu_aarch64_freebsd.c
diff --git a/crypto/fipsmodule/cpucap/cpu_aarch64_openbsd.c b/crypto/fipsmodule/cpucap/cpu_aarch64_openbsd.c
diff --git a/crypto/fipsmodule/cpucap/cpu_aarch64_sysreg.c b/crypto/fipsmodule/cpucap/cpu_aarch64_sysreg.c
@@ -14,8 +14,11 @@
 
 #include "../../internal.h"
 
+// While Arm system registers are normally not available to userspace, FreeBSD
+// expects userspace to simply read them. It traps the reads and fills in CPU
+// capabilities.
 #if defined(OPENSSL_AARCH64) && !defined(OPENSSL_STATIC_ARMCAP) && \
-    defined(ANDROID_BAREMETAL)
+    (defined(ANDROID_BAREMETAL) || defined(OPENSSL_FREEBSD))
 
 #include <openssl/arm_arch.h>
 
@@ -86,4 +89,5 @@ static uint32_t read_armcap(void) {
 
 void OPENSSL_cpuid_setup(void) { OPENSSL_armcap_P |= read_armcap(); }
 
-#endif  // OPENSSL_AARCH64 && !OPENSSL_STATIC_ARMCAP && ANDROID_BAREMETAL
+#endif  // OPENSSL_AARCH64 && !OPENSSL_STATIC_ARMCAP &&
+        // (ANDROID_BAREMETAL || OPENSSL_FREEBSD)
diff --git a/crypto/fipsmodule/cpucap/internal.h b/crypto/fipsmodule/cpucap/internal.h
@@ -136,9 +136,13 @@ OPENSSL_INLINE int CRYPTO_is_VBMI2_capable(void) {
 
 #if defined(OPENSSL_ARM) || defined(OPENSSL_AARCH64)
 
-#if defined(OPENSSL_APPLE) && defined(OPENSSL_ARM)
-// We do not detect any features at runtime for Apple's 32-bit ARM platforms. On
-// 64-bit ARM, we detect some post-ARMv8.0 features.
+// We do not detect any features at runtime on several 32-bit Arm platforms.
+// Apple platforms and OpenBSD require NEON and moved to 64-bit to pick up Armv8
+// extensions. Android baremetal does not aim to support 32-bit Arm at all, but
+// it simplifies things to make it build.
+#if defined(OPENSSL_ARM) && !defined(OPENSSL_STATIC_ARMCAP) && \
+    (defined(OPENSSL_APPLE) || defined(OPENSSL_OPENBSD) ||     \
+     defined(ANDROID_BAREMETAL))
 #define OPENSSL_STATIC_ARMCAP
 #endif