| 1 | //===---------- Linux implementation of the POSIX posix_madvise function --===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | #include "src/sys/mman/posix_madvise.h" |
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| 10 | |
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| 11 | #include "src/__support/OSUtil/syscall.h" // For internal syscall function. |
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| 12 | #include "src/__support/common.h" |
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| 13 | |
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| 14 | #include <sys/syscall.h> // For syscall numbers. |
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| 15 | |
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| 16 | namespace LIBC_NAMESPACE { |
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| 17 | |
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| 18 | // This function is currently linux only. It has to be refactored suitably if |
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| 19 | // posix_madvise is to be supported on non-linux operating systems also. |
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| 20 | LLVM_LIBC_FUNCTION(int, posix_madvise, (void *addr, size_t size, int advice)) { |
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| 21 | // POSIX_MADV_DONTNEED does nothing because the default MADV_DONTNEED may |
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| 22 | // cause data loss, which the posix madvise does not allow. |
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| 23 | if (advice == POSIX_MADV_DONTNEED) { |
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| 24 | return 0; |
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| 25 | } |
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| 26 | int ret = LIBC_NAMESPACE::syscall_impl<int>( |
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| 27 | SYS_madvise, ts: reinterpret_cast<long>(addr), ts: size, ts: advice); |
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| 28 | return ret < 0 ? -ret : 0; |
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| 29 | } |
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| 30 | |
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| 31 | } // namespace LIBC_NAMESPACE |
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| 32 | |
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