Merging upstream version 127.0.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 33 insertions, 0 deletions

diff --git a/third_party/rust/getrandom/src/linux_android_with_fallback.rs b/third_party/rust/getrandom/src/linux_android_with_fallback.rs
new file mode 100644
index 0000000000..0f5ea8a992
--- /dev/null
+++ b/third_party/rust/getrandom/src/linux_android_with_fallback.rs
@@ -0,0 +1,33 @@
+//! Implementation for Linux / Android with `/dev/urandom` fallback
+use crate::{
+    lazy::LazyBool,
+    util_libc::{getrandom_syscall, last_os_error, sys_fill_exact},
+    {use_file, Error},
+};
+use core::mem::MaybeUninit;
+
+pub fn getrandom_inner(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
+    // getrandom(2) was introduced in Linux 3.17
+    static HAS_GETRANDOM: LazyBool = LazyBool::new();
+    if HAS_GETRANDOM.unsync_init(is_getrandom_available) {
+        sys_fill_exact(dest, getrandom_syscall)
+    } else {
+        use_file::getrandom_inner(dest)
+    }
+}
+
+fn is_getrandom_available() -> bool {
+    if getrandom_syscall(&mut []) < 0 {
+        match last_os_error().raw_os_error() {
+            Some(libc::ENOSYS) => false, // No kernel support
+            // The fallback on EPERM is intentionally not done on Android since this workaround
+            // seems to be needed only for specific Linux-based products that aren't based
+            // on Android. See https://github.com/rust-random/getrandom/issues/229.
+            #[cfg(target_os = "linux")]
+            Some(libc::EPERM) => false, // Blocked by seccomp
+            _ => true,
+        }
+    } else {
+        true
+    }
+}