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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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d8a866c766
As discussed here: https://lore.kernel.org/lkml/Z9RRkL1hom48z3Tt@google.com/ This code could benefit from some more commentary. To avoid needing to comment the same thing in multiple places (I guess more of these SKIPs will need to be added over time, for now I am only like 20% of the way through Project Run run_vmtests.sh Successfully), add a dummy "skip tests for this specific reason" function that basically just serves as a hook to hang comments on. Link: https://lkml.kernel.org/r/20250317-9pfs-comments-v1-1-9ac96043e146@google.com Signed-off-by: Brendan Jackman <jackmanb@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
126 lines
2.8 KiB
C
126 lines
2.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2018 Dmitry Safonov, Arista Networks
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*
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* MAP_POPULATE | MAP_PRIVATE should COW VMA pages.
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*/
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#define _GNU_SOURCE
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#include <errno.h>
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#include <fcntl.h>
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#include <sys/mman.h>
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#include <sys/socket.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "../kselftest.h"
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#include "vm_util.h"
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#define MMAP_SZ 4096
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#define BUG_ON(condition, description) \
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do { \
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if (condition) \
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ksft_exit_fail_msg("[FAIL]\t%s:%d\t%s:%s\n", \
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__func__, __LINE__, (description), \
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strerror(errno)); \
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} while (0)
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#define TESTS_IN_CHILD 2
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static void parent_f(int sock, unsigned long *smap, int child)
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{
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int status, ret;
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ret = read(sock, &status, sizeof(int));
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BUG_ON(ret <= 0, "read(sock)");
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*smap = 0x22222BAD;
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ret = msync(smap, MMAP_SZ, MS_SYNC);
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BUG_ON(ret, "msync()");
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ret = write(sock, &status, sizeof(int));
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BUG_ON(ret <= 0, "write(sock)");
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waitpid(child, &status, 0);
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/* The ksft macros don't keep counters between processes */
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ksft_cnt.ksft_pass = WEXITSTATUS(status);
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ksft_cnt.ksft_fail = TESTS_IN_CHILD - WEXITSTATUS(status);
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}
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static int child_f(int sock, unsigned long *smap, int fd)
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{
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int ret, buf = 0;
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smap = mmap(0, MMAP_SZ, PROT_READ | PROT_WRITE,
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MAP_PRIVATE | MAP_POPULATE, fd, 0);
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BUG_ON(smap == MAP_FAILED, "mmap()");
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BUG_ON(*smap != 0xdeadbabe, "MAP_PRIVATE | MAP_POPULATE changed file");
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ret = write(sock, &buf, sizeof(int));
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BUG_ON(ret <= 0, "write(sock)");
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ret = read(sock, &buf, sizeof(int));
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BUG_ON(ret <= 0, "read(sock)");
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ksft_test_result(*smap != 0x22222BAD, "MAP_POPULATE COW private page\n");
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ksft_test_result(*smap == 0xdeadbabe, "The mapping state\n");
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/* The ksft macros don't keep counters between processes */
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return ksft_cnt.ksft_pass;
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}
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int main(int argc, char **argv)
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{
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int sock[2], child, ret;
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FILE *ftmp;
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unsigned long *smap;
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ksft_print_header();
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ksft_set_plan(TESTS_IN_CHILD);
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ftmp = tmpfile();
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BUG_ON(!ftmp, "tmpfile()");
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ret = ftruncate(fileno(ftmp), MMAP_SZ);
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if (ret < 0 && errno == ENOENT) {
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skip_test_dodgy_fs("ftruncate()");
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}
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BUG_ON(ret, "ftruncate()");
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smap = mmap(0, MMAP_SZ, PROT_READ | PROT_WRITE,
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MAP_SHARED, fileno(ftmp), 0);
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BUG_ON(smap == MAP_FAILED, "mmap()");
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*smap = 0xdeadbabe;
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/* Probably unnecessary, but let it be. */
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ret = msync(smap, MMAP_SZ, MS_SYNC);
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BUG_ON(ret, "msync()");
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ret = socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sock);
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BUG_ON(ret, "socketpair()");
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child = fork();
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BUG_ON(child == -1, "fork()");
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if (child) {
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ret = close(sock[0]);
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BUG_ON(ret, "close()");
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parent_f(sock[1], smap, child);
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ksft_finished();
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}
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ret = close(sock[1]);
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BUG_ON(ret, "close()");
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return child_f(sock[0], smap, fileno(ftmp));
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}
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