dda2f556c3
We used shm_open with mmap to share libfuzzer's coverage bitmap with child (runner) processes. The same functionality can be achieved with MAP_SHARED | MAP_ANONYMOUS, since we do not care about naming or permissioning the shared memory object. Signed-off-by: Alexander Bulekov <alxndr@bu.edu> Message-Id: <20200622165040.15121-1-alxndr@bu.edu> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
42 lines
1.1 KiB
C
42 lines
1.1 KiB
C
/*
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* Fork-based fuzzing helpers
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*
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* Copyright Red Hat Inc., 2019
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*
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* Authors:
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* Alexander Bulekov <alxndr@bu.edu>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*
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*/
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#include "qemu/osdep.h"
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#include "fork_fuzz.h"
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void counter_shm_init(void)
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{
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/* Copy what's in the counter region to a temporary buffer.. */
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void *copy = malloc(&__FUZZ_COUNTERS_END - &__FUZZ_COUNTERS_START);
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memcpy(copy,
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&__FUZZ_COUNTERS_START,
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&__FUZZ_COUNTERS_END - &__FUZZ_COUNTERS_START);
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/* Map a shared region over the counter region */
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if (mmap(&__FUZZ_COUNTERS_START,
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&__FUZZ_COUNTERS_END - &__FUZZ_COUNTERS_START,
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PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED | MAP_ANONYMOUS,
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0, 0) == MAP_FAILED) {
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perror("Error: ");
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exit(1);
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}
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/* Copy the original data back to the counter-region */
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memcpy(&__FUZZ_COUNTERS_START, copy,
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&__FUZZ_COUNTERS_END - &__FUZZ_COUNTERS_START);
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free(copy);
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}
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