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a008c76b56
The fix for BZ#21270 (commit 158d5fa0e1) added a mask to avoid offset larger
than 1^44 to be used along __NR_mmap2. However mips64n32 users __NR_mmap,
as mips64n64, but still defines off_t as old non-LFS type (other ILP32, such
x32, defines off_t being equal to off64_t). This leads to use the same
mask meant only for __NR_mmap2 call for __NR_mmap, thus limiting the maximum
offset it can use with mmap64.
This patch fixes by setting the high mask only for __NR_mmap2 usage. The
posix/tst-mmap-offset.c already tests it and also fails for mips64n32. The
patch also change the test to check for an arch-specific header that defines
the maximum supported offset.
Checked on x86_64-linux-gnu, i686-linux-gnu, and I also tests tst-mmap-offset
on qemu simulated mips64 with kernel 3.2.0 kernel for both mips-linux-gnu and
mips64-n32-linux-gnu.
[BZ #24699]
* posix/tst-mmap-offset.c: Mention BZ #24699.
(do_test_bz21270): Rename to do_test_large_offset and use
mmap64_maximum_offset to check for maximum expected offset value.
* sysdeps/generic/mmap_info.h: New file.
* sysdeps/unix/sysv/linux/mips/mmap_info.h: Likewise.
* sysdeps/unix/sysv/linux/mmap64.c (MMAP_OFF_HIGH_MASK): Define iff
__NR_mmap2 is used.
120 lines
3.2 KiB
C
120 lines
3.2 KiB
C
/* BZ #18877, BZ #21270, and BZ #24699 mmap offset test.
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Copyright (C) 2015-2019 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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<http://www.gnu.org/licenses/>. */
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#include <stdint.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 <errno.h>
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#include <sys/mman.h>
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#include <mmap_info.h>
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#include <support/check.h>
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static int fd;
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static long int page_shift;
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static char fname[] = "/tmp/tst-mmap-offset-XXXXXX";
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static void
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do_prepare (int argc, char **argv)
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{
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fd = mkstemp64 (fname);
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if (fd < 0)
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FAIL_EXIT1 ("mkstemp failed");
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if (unlink (fname))
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FAIL_EXIT1 ("unlink failed");
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long sz = sysconf(_SC_PAGESIZE);
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if (sz == -1)
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sz = 4096L;
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page_shift = ffs (sz) - 1;
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}
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#define PREPARE do_prepare
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/* Check if negative offsets are handled correctly by mmap. */
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static int
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do_test_bz18877 (void)
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{
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const int prot = PROT_READ | PROT_WRITE;
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const int flags = MAP_SHARED;
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const unsigned long length = 0x10000;
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const unsigned long offset = 0xace00000;
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const unsigned long size = offset + length;
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void *addr;
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if (ftruncate64 (fd, size))
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FAIL_RET ("ftruncate64 failed");
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addr = mmap (NULL, length, prot, flags, fd, offset);
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if (MAP_FAILED == addr)
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FAIL_RET ("mmap failed");
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/* This memcpy is likely to SIGBUS if mmap has messed up with offset. */
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memcpy (addr, fname, sizeof (fname));
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return 0;
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}
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/* Check if invalid offset are handled correctly by mmap. */
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static int
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do_test_large_offset (void)
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{
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/* For architectures with sizeof (off_t) < sizeof (off64_t) mmap is
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implemented with __SYS_mmap2 syscall and the offset is represented in
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multiples of page size. For offset larger than
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'1 << (page_shift + 8 * sizeof (off_t))' (that is, 1<<44 on system with
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page size of 4096 bytes) the system call silently truncates the offset.
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For this case glibc mmap implementation returns EINVAL. */
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const int prot = PROT_READ | PROT_WRITE;
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const int flags = MAP_SHARED;
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const int64_t offset = 1ULL << (page_shift + 8 * sizeof (uint32_t));
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const size_t length = 4096;
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void *addr = mmap64 (NULL, length, prot, flags, fd, offset);
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if (mmap64_maximum_offset (page_shift) < UINT64_MAX)
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{
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if ((addr != MAP_FAILED) && (errno != EINVAL))
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FAIL_RET ("mmap succeed");
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}
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else
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{
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if (addr == MAP_FAILED)
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FAIL_RET ("mmap failed");
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}
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return 0;
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}
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int
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do_test (void)
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{
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int ret = 0;
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ret += do_test_bz18877 ();
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ret += do_test_large_offset ();
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return ret;
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}
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#include <support/test-driver.c>
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