8ec4c5dae3
coredump_phnum intends to generate a core file with many PT_LOAD segments. Previously it called mmap() in a loop with alternating protections, relying on each mapping following the previous, to produce a core file with many page-sized PT_LOAD segments. With ASLR on we no longer have this property of each mmap() following the previous. Instead, perform a single allocation, and then use mprotect() to set alternating pages to PROT_READ. PR: 259970 Reported by: lwhsu, mw Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D33070
65 lines
2.0 KiB
C
65 lines
2.0 KiB
C
/*
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* Copyright (c) 2016, Conrad Meyer
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <sys/param.h>
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#include <sys/mman.h>
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#include <err.h>
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#include <stdint.h>
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#include <stdlib.h>
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/*
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* This program is intended to create a bunch of segment mappings, then dump
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* core.
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*/
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int
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main(int argc __unused, char **argv __unused)
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{
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void *v;
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size_t i, pages;
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pages = UINT16_MAX + 1000;
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v = mmap(NULL, pages * PAGE_SIZE, PROT_READ | PROT_WRITE,
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MAP_ANON | MAP_PRIVATE, -1, 0);
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if (v == NULL)
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err(1, "mmap");
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for (i = 0; i < pages; i += 2) {
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/*
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* Alternate protections to interleave RW and R PT_LOAD
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* segments.
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*/
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if (mprotect((char *)v + i * PAGE_SIZE, PAGE_SIZE,
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PROT_READ) != 0)
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err(1, "mprotect");
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}
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/* Dump core. */
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abort();
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}
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