#define MMAP2_SHIFT 12 // 2**12 == 4096
void* mmap64(void* addr, size_t size, int prot, int flags, int fd, off64_t offset) {
- if (offset & ((1UL << MMAP2_SHIFT)-1)) {
+ if (offset < 0 || (offset & ((1UL << MMAP2_SHIFT)-1)) != 0) {
errno = EINVAL;
return MAP_FAILED;
}
- uint64_t unsigned_offset = static_cast<uint64_t>(offset); // To avoid sign extension.
- void* result = __mmap2(addr, size, prot, flags, fd, unsigned_offset >> MMAP2_SHIFT);
-
+ void* result = __mmap2(addr, size, prot, flags, fd, offset >> MMAP2_SHIFT);
if (result != MAP_FAILED && (flags & (MAP_PRIVATE | MAP_ANONYMOUS)) != 0) {
ErrnoRestorer errno_restorer;
madvise(result, size, MADV_MERGEABLE);
}
void* mmap(void* addr, size_t size, int prot, int flags, int fd, off_t offset) {
- return mmap64(addr, size, prot, flags, fd, static_cast<off64_t>(offset) & 0xffffffff);
+ return mmap64(addr, size, prot, flags, fd, static_cast<off64_t>(offset));
}
--- /dev/null
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <gtest/gtest.h>
+
+#include <sys/mman.h>
+#include <unistd.h>
+
+TEST(sys_mman, mmap_negative) {
+ off_t off = -sysconf(_SC_PAGESIZE); // Aligned but negative.
+ ASSERT_EQ(MAP_FAILED, mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, off));
+}
+
+TEST(sys_mman, mmap64_negative) {
+ off64_t off64 = -sysconf(_SC_PAGESIZE); // Aligned but negative.
+ ASSERT_EQ(MAP_FAILED, mmap64(NULL, 4096, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, off64));
+}