[libc-commits] [libc] [libc] Add Linux mman extension remap_file_pages. (PR #110307)

[Michael Jones via libc-commits]

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@@ -0,0 +1,88 @@
+//===-- Unittests for remap_file_pages ------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/errno/libc_errno.h"
+#include "src/sys/mman/mmap.h"
+#include "src/sys/mman/munmap.h"
+#include "src/sys/mman/remap_file_pages.h"
+#include "src/unistd/sysconf.h"
+#include "test/UnitTest/ErrnoSetterMatcher.h"
+#include "test/UnitTest/Test.h"
+#include <fcntl.h>
+
+#include <sys/mman.h>
+
+using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
+using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
+
+TEST(LlvmLibcRemapFilePagesTest, NoError) {
+  size_t page_size = sysconf(_SC_PAGE_SIZE);
+  ASSERT_GT(page_size, size_t(0));
+
+  // Create a file-backed mapping
+  int fd = open("/dev/zero", O_RDWR);
+  ASSERT_GT(fd, 0);
+
+  // First, allocate some memory using mmap
+  size_t alloc_size = 2 * page_size;
+  LIBC_NAMESPACE::libc_errno = 0;
+  void *addr = LIBC_NAMESPACE::mmap(nullptr, alloc_size, PROT_READ | PROT_WRITE,
+                                    MAP_SHARED, fd, 0);
+  ASSERT_ERRNO_SUCCESS();
+  EXPECT_NE(addr, MAP_FAILED);
+
+  // Reset error number for the new function
+  LIBC_NAMESPACE::libc_errno = 0;
+
+  // Now try to remap the pages
+  EXPECT_THAT(LIBC_NAMESPACE::remap_file_pages(addr, page_size, 0, 1, 0),
+              Succeeds());
+
+  // Reset error number for the new function
+  LIBC_NAMESPACE::libc_errno = 0;
+
+  // Clean up
+  EXPECT_THAT(LIBC_NAMESPACE::munmap(addr, alloc_size), Succeeds());
+}
+
+TEST(LlvmLibcRemapFilePagesTest, ErrorInvalidFlags) {
+  size_t page_size = sysconf(_SC_PAGE_SIZE);
+  ASSERT_GT(page_size, size_t(0));
+
+  // Create a file-backed mapping
+  int fd = open("/dev/zero", O_RDWR);
+  ASSERT_GT(fd, 0);
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michaelrj-google wrote:

same file path stuff as above, though make sure to use a different name since tests may be run in parallel.

https://github.com/llvm/llvm-project/pull/110307