The call index check episodically fails:
2017/10/02 22:07:32 bad call index 1, calls 1, program:
under unknown circumstances. I've looked at the code again
and don't see where/how we can mess CallIndex.
Added a new test for minimization that especially checks resulting
CallIndex.
It would be good to understand what happens, but we don't have
any reproducers. CallIndex is actually unused at this point.
Manager only needs call name. So remove CallIndex entirely.
We have implemented a new version of KCOV, which is able to dump
comparison operands' data, obtained from Clang's instrumentation hooks
__sanitizer_cov_trace_cmp[1248], __sanitizer_cov_trace_const_cmp[1248]
and __sanitizer_cov_trace_switch.
Current KCOV implementation can work in two modes: "Dump only the PCs"
or "Dump only comparisons' data". Mode selection is done by the
following series of calls:
fd = open(KCOV_PATH, ...); // works as previous
ioctl(fd, KCOV_INIT_TRACE, ...); // works as previous
mmap(fd, ...); // works as previous
ioctl(fd, KCOV_ENABLE, mode);
// mode = KCOV_MODE_TRACE_CMP or mode = KCOV_MODE_TRACE_PC
Note that this new interface is backwards compatible, as old KCOV
devices will just return -EINVAL for the last ioctl. This way we can
distinguish if the KCOV device is able to dump the comparisons.
Main changes in this commit:
1. Fuzzer now checks at startup which type (new/old) of KCOV device
is running.
2. Executor now receives an additional flag, which indicates if
executor should read the comparisons data from KCOV. The flag works on
per-call basis, so executor can collect PCs or Comps for each
individual syscall.
Currently hub allows managers to exchange programs from corpus.
But reproducers are not exchanged and we don't know if a crash
happens on other managers as well or not.
Allow hub to exchange reproducers.
Reproducers are stored in a separate db file with own sequence numbers.
This allows to throttle distribution of reproducers to managers,
so that they are not overloaded with reproducers and don't lose them on restarts.
Based on patch by Andrey Konovalov:
https://github.com/google/syzkaller/pull/325Fixes#282
