581c785bf3
I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 7061 files FOO. I then removed trailing white space from math/tgmath.h, support/tst-support-open-dev-null-range.c, and sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following obscure pre-commit check failure diagnostics from Savannah. I don't know why I run into these diagnostics whereas others evidently do not. remote: *** 912-#endif remote: *** 913: remote: *** 914- remote: *** error: lines with trailing whitespace found ... remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
53 lines
2 KiB
C
53 lines
2 KiB
C
/* Memory allocation next to an unmapped page.
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Copyright (C) 2017-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <support/check.h>
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#include <support/next_to_fault.h>
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#include <support/xunistd.h>
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#include <sys/mman.h>
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#include <sys/param.h>
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struct support_next_to_fault
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support_next_to_fault_allocate (size_t size)
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{
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long page_size = sysconf (_SC_PAGE_SIZE);
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TEST_VERIFY_EXIT (page_size > 0);
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struct support_next_to_fault result;
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result.region_size = roundup (size, page_size) + page_size;
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if (size + page_size <= size || result.region_size <= size)
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FAIL_EXIT1 ("support_next_to_fault_allocate (%zu): overflow", size);
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result.region_start
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= xmmap (NULL, result.region_size, PROT_READ | PROT_WRITE,
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MAP_PRIVATE | MAP_ANONYMOUS, -1);
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/* Unmap the page after the allocation. */
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xmprotect (result.region_start + (result.region_size - page_size),
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page_size, PROT_NONE);
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/* Align the allocation within the region so that it ends just
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before the PROT_NONE page. */
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result.buffer = result.region_start + result.region_size - page_size - size;
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result.length = size;
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return result;
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}
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void
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support_next_to_fault_free (struct support_next_to_fault *ntf)
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{
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xmunmap (ntf->region_start, ntf->region_size);
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*ntf = (struct support_next_to_fault) { NULL, };
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}
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