76 lines
1.7 KiB
C
76 lines
1.7 KiB
C
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// SPDX-License-Identifier: LGPL-2.1-or-later
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/*
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* Copyright (C) 2005-2006 IBM Corporation.
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* Author: Mel Gorman
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*/
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/*\
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* [Description]
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*
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* readahead() on some kernels can cause the reservation counter to get
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* corrupted. The problem is that the pages are allocated for the
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* reservation but not faulted in at the time of allocation. The
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* counters do not get updated and effectively "leak". This test
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* identifies whether the kernel is vulnerable to the problem or not.
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* It's fixed in kernel by commit f2deae9d4e70.
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*/
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#define _GNU_SOURCE
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#include "hugetlb.h"
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#define MNTPOINT "hugetlbfs/"
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static long hpage_size;
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static int fd = -1;
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static void run_test(void)
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{
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void *p;
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unsigned long initial_rsvd, map_rsvd, readahead_rsvd, end_rsvd;
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fd = tst_creat_unlinked(MNTPOINT, 0);
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initial_rsvd = SAFE_READ_MEMINFO(MEMINFO_HPAGE_RSVD);
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p = SAFE_MMAP(NULL, hpage_size, PROT_READ|PROT_WRITE, MAP_SHARED,
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fd, 0);
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map_rsvd = SAFE_READ_MEMINFO(MEMINFO_HPAGE_RSVD);
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tst_res(TINFO, "map_rsvd: %lu", map_rsvd);
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readahead(fd, 0, hpage_size);
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readahead_rsvd = SAFE_READ_MEMINFO(MEMINFO_HPAGE_RSVD);
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tst_res(TINFO, "readahead_rsvd: %lu", readahead_rsvd);
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memset(p, 1, hpage_size);
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SAFE_MUNMAP(p, hpage_size);
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SAFE_CLOSE(fd);
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end_rsvd = SAFE_READ_MEMINFO(MEMINFO_HPAGE_RSVD);
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TST_EXP_EQ_LU(end_rsvd, initial_rsvd);
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}
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static void setup(void)
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{
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hpage_size = tst_get_hugepage_size();
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}
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static void cleanup(void)
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{
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if (fd >= 0)
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SAFE_CLOSE(fd);
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}
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static struct tst_test test = {
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.tags = (struct tst_tag[]) {
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{"linux-git", "f2deae9d4e70"},
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{}
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},
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.needs_root = 1,
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.mntpoint = MNTPOINT,
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.needs_hugetlbfs = 1,
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.needs_tmpdir = 1,
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.setup = setup,
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.cleanup = cleanup,
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.test_all = run_test,
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.hugepages = {1, TST_NEEDS},
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};
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