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am 4449fe96: Merge "Fix 32-bit mmap/mmap64 handling of negative offsets."

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* commit '4449fe9675671264746af4876bd959af8e9fee82':
  Fix 32-bit mmap/mmap64 handling of negative offsets.
This commit is contained in:
Elliott Hughes 2014-01-28 01:03:26 +00:00 committed by Android Git Automerger
commit 4bc229eb02
3 changed files with 34 additions and 5 deletions
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8
libc/bionic/mmap.cpp
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@ -38,14 +38,12 @@ extern "C" void* __mmap2(void*, size_t, int, int, int, size_t);
#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);
@ -55,5 +53,5 @@ void* mmap64(void* addr, size_t size, int prot, int flags, int fd, off64_t offse
}
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));
}

1
tests/Android.mk
View File

@ -61,6 +61,7 @@ test_src_files = \
strings_test.cpp \
stubs_test.cpp \
sys_epoll_test.cpp \
sys_mman_test.cpp \
sys_resource_test.cpp \
sys_select_test.cpp \
sys_sendfile_test.cpp \

30
tests/sys_mman_test.cpp Normal file
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@ -0,0 +1,30 @@
/*
* 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));
}