[libc-commits] [libc] [libc] Fix aligned_alloc used in hermetic tests. (PR #213041)

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llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-libc

Author: Alexey Samsonov (vonosmas)

<details>
<summary>Changes</summary>

Make sure to use provided alignment both for the pointer to the returned memory chunk and the size.

This fixes occasional segfaults in `hsearch` tests after ce62aab97e58c52e6bb0972c49d6fd1aaa6a08a0, since
hash-table bitmask implementation uses SSE2 intrinsics with 16-byte alignment.

---
Full diff: https://github.com/llvm/llvm-project/pull/213041.diff


1 Files Affected:

- (modified) libc/test/UnitTest/HermeticTestUtils.cpp (+3) 


``````````diff
diff --git a/libc/test/UnitTest/HermeticTestUtils.cpp b/libc/test/UnitTest/HermeticTestUtils.cpp
index bcc42bed98eb5..05e2bbdde2603 100644
--- a/libc/test/UnitTest/HermeticTestUtils.cpp
+++ b/libc/test/UnitTest/HermeticTestUtils.cpp
@@ -73,6 +73,9 @@ int atexit(void (*func)(void)) { return LIBC_NAMESPACE::atexit(func); }
 void *aligned_alloc(size_t align, size_t s) {
   if (align & (align - 1)) // Must be power of 2
     return nullptr;
+  uintptr_t ptr_val = reinterpret_cast<uintptr_t>(ptr);
+  uintptr_t aligned_ptr_val = ((ptr_val + align - 1) / align) * align;
+  ptr = reinterpret_cast<uint8_t *>(aligned_ptr_val);
   s = ((s + align - 1) / align) * align;
   void *mem = ptr;
   ptr += s;

``````````

</details>


https://github.com/llvm/llvm-project/pull/213041