Merge branch 'master' into linux_raw

Author: newpavlov

.github/workflows/nopanic.yaml

@@ -42,11 +42,11 @@ jobs:
       - name: Check (linux_android_with_fallback.rs)
         run: (exit $( grep -c panic target/release/libgetrandom_wrapper.so ))
 
-      - name: Build (linux_android.rs)
+      - name: Build (getrandom.rs)
         env:
           RUSTFLAGS: -Dwarnings --cfg getrandom_backend="linux_getrandom"
         run: cargo build --release
-      - name: Check (linux_android.rs)
+      - name: Check (getrandom.rs)
         run: (exit $( grep -c panic target/release/libgetrandom_wrapper.so ))
 
       - name: Build (linux_raw.rs)
@@ -105,11 +105,6 @@ jobs:
       - name: Check (rndr.rs)
         run: (exit $( grep -c panic target/aarch64-unknown-linux-gnu/release/libgetrandom_wrapper.so ))
 
-      - name: Build (getrandom.rs)
-        run: cross build --release --target=x86_64-unknown-freebsd
-      - name: Check (getrandom.rs)
-        run: (exit $( grep -c panic target/x86_64-unknown-freebsd/release/libgetrandom_wrapper.so ))
-
       - name: Build (netbsd.rs)
         run: cross build --release --target=x86_64-unknown-netbsd
       - name: Check (netbsd.rs)

.github/workflows/tests.yml

@@ -65,6 +65,10 @@ jobs:
           RUSTFLAGS: -Dwarnings --cfg getrandom_test_linux_fallback
           RUSTDOCFLAGS: -Dwarnings --cfg getrandom_test_linux_fallback
         run: cargo test --features=std
+      - env:
+          RUSTFLAGS: -Dwarnings --cfg getrandom_test_linux_without_fallback
+          RUSTDOCFLAGS: -Dwarnings --cfg getrandom_test_linux_without_fallback
+        run: cargo test --features=std
       - env:
           RUSTFLAGS: -Dwarnings --cfg getrandom_backend="rdrand"
           RUSTDOCFLAGS: -Dwarnings --cfg getrandom_backend="rdrand"

.github/workflows/workspace.yml

@@ -41,8 +41,6 @@ jobs:
       run: cargo clippy -Zbuild-std=core --target x86_64-unknown-fuchsia
     - name: OpenBSD (getentropy.rs)
       run: cargo clippy -Zbuild-std=core --target x86_64-unknown-openbsd
-    - name: FreeBSD (getrandom.rs)
-      run: cargo clippy -Zbuild-std=core --target x86_64-unknown-freebsd
     - name: Hermit (hermit.rs)
       run: cargo clippy -Zbuild-std=core --target x86_64-unknown-hermit
     - name: Web WASM (wasm_js.rs)
@@ -53,7 +51,7 @@ jobs:
       env:
         RUSTFLAGS: -Dwarnings --cfg getrandom_backend="wasm_js" -Ctarget-feature=+atomics,+bulk-memory
       run: cargo clippy -Zbuild-std --target wasm32-unknown-unknown --features wasm_js
-    - name: Linux (linux_android.rs)
+    - name: Linux (getrandom.rs)
       env:
         RUSTFLAGS: -Dwarnings --cfg getrandom_backend="linux_getrandom"
       run: cargo clippy --target x86_64-unknown-linux-gnu

Cargo.toml

@@ -30,7 +30,7 @@ cfg-if = "1"
 compiler_builtins = { version = "0.1", optional = true }
 core = { version = "1.0", optional = true, package = "rustc-std-workspace-core" }
 
-# linux_android / linux_android_with_fallback
+# getrandom / linux_android_with_fallback
 [target.'cfg(all(any(target_os = "linux", target_os = "android"), not(any(getrandom_backend = "custom", getrandom_backend = "linux_raw", getrandom_backend = "rdrand", getrandom_backend = "rndr"))))'.dependencies]
 libc = { version = "0.2.154", default-features = false }
 
@@ -84,6 +84,7 @@ check-cfg = [
   'cfg(getrandom_backend, values("custom", "rdrand", "rndr", "linux_getrandom", "linux_raw", "wasm_js"))',
   'cfg(getrandom_msan)',
   'cfg(getrandom_test_linux_fallback)',
+  'cfg(getrandom_test_linux_without_fallback)',
   'cfg(getrandom_test_netbsd_fallback)',
 ]
 

src/backends.rs

@@ -11,8 +11,8 @@ cfg_if! {
         mod custom;
         pub use custom::*;
     } else if #[cfg(getrandom_backend = "linux_getrandom")] {
-        mod linux_android;
-        pub use linux_android::*;
+        mod getrandom;
+        pub use getrandom::*;
     } else if #[cfg(getrandom_backend = "linux_raw")] {
         mod linux_raw;
         pub use linux_raw::*;
@@ -54,17 +54,6 @@ cfg_if! {
     ))] {
         mod getentropy;
         pub use getentropy::*;
-    } else if #[cfg(any(
-        target_os = "dragonfly",
-        target_os = "freebsd",
-        target_os = "hurd",
-        target_os = "illumos",
-        // Check for target_arch = "arm" to only include the 3DS. Does not
-        // include the Nintendo Switch (which is target_arch = "aarch64").
-        all(target_os = "horizon", target_arch = "arm"),
-    ))] {
-        mod getrandom;
-        pub use getrandom::*;
     } else if #[cfg(any(
         // Rust supports Android API level 19 (KitKat) [0] and the next upgrade targets
         // level 21 (Lollipop) [1], while `getrandom(2)` was added only in
@@ -105,9 +94,19 @@ cfg_if! {
         mod use_file;
         mod linux_android_with_fallback;
         pub use linux_android_with_fallback::*;
-    } else if #[cfg(any(target_os = "android", target_os = "linux"))] {
-        mod linux_android;
-        pub use linux_android::*;
+    } else if #[cfg(any(
+        target_os = "android",
+        target_os = "linux",
+        target_os = "dragonfly",
+        target_os = "freebsd",
+        target_os = "hurd",
+        target_os = "illumos",
+        // Check for target_arch = "arm" to only include the 3DS. Does not
+        // include the Nintendo Switch (which is target_arch = "aarch64").
+        all(target_os = "horizon", target_arch = "arm"),
+    ))] {
+        mod getrandom;
+        pub use getrandom::*;
     } else if #[cfg(target_os = "solaris")] {
         mod solaris;
         pub use solaris::*;

src/backends/getrandom.rs

@@ -16,7 +16,7 @@
 //! nothing. On illumos, the default pool is used to implement getentropy(2),
 //! so we assume it is acceptable here.
 use crate::Error;
-use core::{ffi::c_void, mem::MaybeUninit};
+use core::mem::MaybeUninit;
 
 pub use crate::util::{inner_u32, inner_u64};
 
@@ -26,6 +26,6 @@ mod util_libc;
 #[inline]
 pub fn fill_inner(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
     util_libc::sys_fill_exact(dest, |buf| unsafe {
-        libc::getrandom(buf.as_mut_ptr().cast::<c_void>(), buf.len(), 0)
+        libc::getrandom(buf.as_mut_ptr().cast(), buf.len(), 0)
     })
 }

src/backends/linux_android.rs

@@ -3,8 +3,8 @@ use super::use_file;
 use crate::Error;
 use core::{
     ffi::c_void,
-    mem::{self, MaybeUninit},
-    ptr::{self, NonNull},
+    mem::{transmute, MaybeUninit},
+    ptr::NonNull,
     sync::atomic::{AtomicPtr, Ordering},
 };
 use use_file::util_libc;
@@ -17,18 +17,28 @@ type GetRandomFn = unsafe extern "C" fn(*mut c_void, libc::size_t, libc::c_uint)
 /// or not supported by kernel.
 const NOT_AVAILABLE: NonNull<c_void> = unsafe { NonNull::new_unchecked(usize::MAX as *mut c_void) };
 
-static GETRANDOM_FN: AtomicPtr<c_void> = AtomicPtr::new(ptr::null_mut());
+static GETRANDOM_FN: AtomicPtr<c_void> = AtomicPtr::new(core::ptr::null_mut());
 
 #[cold]
 #[inline(never)]
 fn init() -> NonNull<c_void> {
-    static NAME: &[u8] = b"getrandom\0";
-    let name_ptr = NAME.as_ptr().cast::<libc::c_char>();
-    let raw_ptr = unsafe { libc::dlsym(libc::RTLD_DEFAULT, name_ptr) };
+    // Use static linking to `libc::getrandom` on MUSL targets and `dlsym` everywhere else
+    #[cfg(not(target_env = "musl"))]
+    let raw_ptr = {
+        static NAME: &[u8] = b"getrandom\0";
+        let name_ptr = NAME.as_ptr().cast::<libc::c_char>();
+        unsafe { libc::dlsym(libc::RTLD_DEFAULT, name_ptr) }
+    };
+    #[cfg(target_env = "musl")]
+    let raw_ptr = {
+        let fptr: GetRandomFn = libc::getrandom;
+        unsafe { transmute::<GetRandomFn, *mut c_void>(fptr) }
+    };
+
     let res_ptr = match NonNull::new(raw_ptr) {
         Some(fptr) => {
-            let getrandom_fn = unsafe { mem::transmute::<NonNull<c_void>, GetRandomFn>(fptr) };
-            let dangling_ptr = ptr::NonNull::dangling().as_ptr();
+            let getrandom_fn = unsafe { transmute::<NonNull<c_void>, GetRandomFn>(fptr) };
+            let dangling_ptr = NonNull::dangling().as_ptr();
             // Check that `getrandom` syscall is supported by kernel
             let res = unsafe { getrandom_fn(dangling_ptr, 0, 0) };
             if cfg!(getrandom_test_linux_fallback) {
@@ -50,11 +60,16 @@ fn init() -> NonNull<c_void> {
         None => NOT_AVAILABLE,
     };
 
+    #[cfg(getrandom_test_linux_without_fallback)]
+    if res_ptr == NOT_AVAILABLE {
+        panic!("Fallback is triggered with enabled `getrandom_test_linux_without_fallback`")
+    }
+
     GETRANDOM_FN.store(res_ptr.as_ptr(), Ordering::Release);
     res_ptr
 }
 
-// prevent inlining of the fallback implementation
+// Prevent inlining of the fallback implementation
 #[inline(never)]
 fn use_file_fallback(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
     use_file::fill_inner(dest)
@@ -78,7 +93,7 @@ pub fn fill_inner(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
         use_file_fallback(dest)
     } else {
         // note: `transmute` is currently the only way to convert a pointer into a function reference
-        let getrandom_fn = unsafe { mem::transmute::<NonNull<c_void>, GetRandomFn>(fptr) };
+        let getrandom_fn = unsafe { transmute::<NonNull<c_void>, GetRandomFn>(fptr) };
         util_libc::sys_fill_exact(dest, |buf| unsafe {
             getrandom_fn(buf.as_mut_ptr().cast(), buf.len(), 0)
         })