cpu arm: Fix static feature detection initialization.

Commit f932b941bd1f59782cb3db8f7cd7b8b2c9842ee9 was incomplete and
wrong. On targets where we do any static or dynamic feature detection
and where we have these global variables, we need to unconditionally
write the detected features to the global variable so that assembly
can see them. Since we do static feature detection regardless of
operating system, the initialization of the global most be done
without any conditions on the operating system.

Cargo.toml

@@ -174,7 +174,7 @@ name = "ring"
 getrandom = { version = "0.2.10" }
 untrusted = { version = "0.9" }
 
-[target.'cfg(any(target_arch = "x86",target_arch = "x86_64", all(any(target_arch = "aarch64", target_arch = "arm"), any(target_os = "android", target_os = "fuchsia", target_os = "linux", target_os = "windows"))))'.dependencies]
+[target.'cfg(any(target_arch = "aarch64", target_arch = "arm", target_arch = "x86",target_arch = "x86_64"))'.dependencies]
 spin = { version = "0.9.8", default-features = false, features = ["once"] }
 
 [target.'cfg(all(any(target_os = "android", target_os = "linux"), any(target_arch = "aarch64", target_arch = "arm")))'.dependencies]

src/cpu.rs

@@ -24,39 +24,21 @@ pub(crate) struct Features(());
 
 #[inline(always)]
 pub(crate) fn features() -> Features {
-    // We don't do runtime feature detection on aarch64-apple-* as all AAarch64
-    // features we use are available on every device since the first devices.
+    #[cfg(any(target_arch = "aarch64", target_arch = "arm"))]
+    use arm::init_global_shared_with_assembly;
+
+    #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+    use intel::init_global_shared_with_assembly;
+
     #[cfg(any(
+        target_arch = "aarch64",
+        target_arch = "arm",
         target_arch = "x86",
         target_arch = "x86_64",
-        all(
-            any(target_arch = "aarch64", target_arch = "arm"),
-            any(
-                target_os = "android",
-                target_os = "fuchsia",
-                target_os = "linux",
-                target_os = "windows"
-            )
-        )
     ))]
     {
         static INIT: spin::Once<()> = spin::Once::new();
-        let () = INIT.call_once(|| {
-            #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
-            {
-                prefixed_extern! {
-                    fn OPENSSL_cpuid_setup();
-                }
-                unsafe {
-                    OPENSSL_cpuid_setup();
-                }
-            }
-
-            #[cfg(any(target_arch = "aarch64", target_arch = "arm"))]
-            {
-                unsafe { arm::initialize_OPENSSL_armcap_P() }
-            }
-        });
+        let () = INIT.call_once(|| unsafe { init_global_shared_with_assembly() });
     }
 
     Features(())

src/cpu/arm.rs

@@ -269,7 +269,7 @@ features! {
 //   `INIT`.
 // - See the safety invariants of `OPENSSL_armcap_P` below.
 #[cfg(any(target_arch = "aarch64", target_arch = "arm"))]
-pub unsafe fn initialize_OPENSSL_armcap_P() {
+pub unsafe fn init_global_shared_with_assembly() {
     let detected = detect_features();
     let filtered = (if cfg!(feature = "unstable-testing-arm-no-hw") {
         AES.mask | SHA256.mask | PMULL.mask

src/cpu/intel.rs

@@ -22,6 +22,16 @@ pub(crate) struct Feature {
     mask: u32,
 }
 
+#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+pub(super) unsafe fn init_global_shared_with_assembly() {
+    prefixed_extern! {
+        fn OPENSSL_cpuid_setup();
+    }
+    unsafe {
+        OPENSSL_cpuid_setup();
+    }
+}
+
 impl Feature {
     #[allow(clippy::needless_return)]
     #[inline(always)]