Auto merge of #155713 - tgross35:150898-regression-test, r=<try>

test: Add a regression test for Apple platforms aborting on `free`


try-job: aarch64-apple

Author: bors

tests/ui/allocator/regression-abort-on-free-issue-150898.rs

@@ -0,0 +1,59 @@
+// Regression test for https://github.com/rust-lang/rust/issues/150898
+//
+// This test fails on Apple platforms with versions containing an allocator
+// bug. If this fails with SIGABRT, you may need to upgrade your system to
+// avoid other unexpected behavior.
+//
+// Note that the failure is non-deterministic so this test may pass even in
+// conditions where the bug is present. That being said, on the author's
+// machine this has a 100% rate of hitting the crash on at least a couple
+// threads.
+//
+// The bug was resolved by macOS 26.4.
+
+//@ run-pass
+//@ only-aarch64-apple-darwin
+//@ compile-flags: -C opt-level=1 -C codegen-units=1
+
+use std::thread;
+
+fn main() {
+    // Running with multiple threads substantially increases the change of
+    // hitting the bug.
+    thread::scope(|s| {
+        for _ in 0..10 {
+            s.spawn(run);
+        }
+    });
+}
+
+fn run() {
+    // This doesn't always fail, so rerun a few times
+    for _ in 0..100 {
+        unsafe {
+            core::arch::asm!(
+                "
+                // Alloc 18 bytes
+                mov x0, #18
+                bl  _malloc
+                // Save the pointer to x21
+                mov x21, x0
+                // Alloc 18 bytes again
+                mov x0, #18
+                bl _malloc
+                // Store the contents of `x13` to the second allocation. `x13` is the
+                // magic register to cause the crash, other registers work well.
+                str x13, [x0]
+                // Free the pointers
+                bl  _free
+                mov x0, x21
+                bl  _free
+                ",
+                out("x0") _,
+                out("x13") _,
+                out("x21") _,
+                clobber_abi("C"),
+            )
+        }
+    }
+}