qemu/tests/qtest/fuzz/fork_fuzz.ld
Alexander Bulekov 3b113229c5 fuzz: add mangled object name to linker script
Previously, we relied on "FuzzerTracePC*(.bss*)" to place libfuzzer's
fuzzer::TPC object into our contiguous shared-memory region. This does
not work for some libfuzzer builds, so this addition identifies the
region by its mangled name: *(.bss._ZN6fuzzer3TPCE);

Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Message-id: 20200512030133.29896-4-alxndr@bu.edu
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-06-05 09:54:48 +01:00

47 lines
1.2 KiB
Plaintext

/*
* We adjust linker script modification to place all of the stuff that needs to
* persist across fuzzing runs into a contiguous section of memory. Then, it is
* easy to re-map the counter-related memory as shared.
*/
SECTIONS
{
.data.fuzz_start : ALIGN(4K)
{
__FUZZ_COUNTERS_START = .;
__start___sancov_cntrs = .;
*(_*sancov_cntrs);
__stop___sancov_cntrs = .;
/* Lowest stack counter */
*(__sancov_lowest_stack);
}
.data.fuzz_ordered :
{
/*
* Coverage counters. They're not necessary for fuzzing, but are useful
* for analyzing the fuzzing performance
*/
__start___llvm_prf_cnts = .;
*(*llvm_prf_cnts);
__stop___llvm_prf_cnts = .;
/* Internal Libfuzzer TracePC object which contains the ValueProfileMap */
FuzzerTracePC*(.bss*);
/*
* In case the above line fails, explicitly specify the (mangled) name of
* the object we care about
*/
*(.bss._ZN6fuzzer3TPCE);
}
.data.fuzz_end : ALIGN(4K)
{
__FUZZ_COUNTERS_END = .;
}
}
/*
* Don't overwrite the SECTIONS in the default linker script. Instead insert the
* above into the default script
*/
INSERT AFTER .data;