This change adds a `csum[kind, type]` type.
The only available kind right now is `ipv4`.
Using `csum[ipv4, int16be]` in `ipv4_header` makes syzkaller calculate
and embed correct checksums into ipv4 packets.
The optimization change removed validation too aggressively.
We do need program validation during deserialization,
because we can get bad programs from corpus or hub.
Restore program validation after deserialization.
A bunch of spot optmizations after cpu/memory profiling:
1. Optimize hot-path coverage comparison in fuzzer.
2. Don't allocate and copy serialized program, serialize directly into shmem.
3. Reduce allocations during parsing of output shmem (encoding/binary sucks).
4. Don't allocate and copy coverage arrays, refer directly to the shmem region
(we are not going to mutate them).
5. Don't validate programs outside of tests, validation allocates tons of memory.
6. Replace the choose primitive with simpler switches.
Choose allocates fullload of memory (for int, func, and everything the func refers).
7. Other minor optimizations.
Currently we generate arrays of size [0,5] with equal probability.
Generate [0,10] with bias towards smaller arrays. But 0 has the lowest probability.
I've benchmark a slightly different change with max array size of 20,
results are somewhat inconclusive: it was better than baseline almost all way,
but baseline suddenly caught up at the end. It also considerably reduced
executions per second (by ~20%). So increasing array size to 10 should be a win...
Currently we stop mutating with 50% probability.
Stop mutating with 33% probability instead.
Benchmark shows both coverage increase and corpus reduction:
baseline oneof3 diff
coverage 65467 65604 137
corpus 35423 35354 -69
exec total 5474879 5023268 -451611
1. Basic support for arm64 kvm testing.
2. Fix compiler warnings in x86 kvm code.
3. Test all pseudo syz calls in csource.
4. Fix handling of real code in x86.
Add ifuzz package that can generate/mutate machine code.
It is based on Intel XED and for now supports only x86 code
(all of real, protected 16/32 and long modes).
This considerably increases KVM coverage.
Add new pseudo syscall syz_kvm_setup_cpu that setups VCPU into
interesting states for execution. KVM is too difficult to setup otherwise.
Lots of improvements possible, but this is a starting point.
bufio.Scanner has a default limit of 4K per line,
if a program contains longer line, it fails.
Extend the limit to 64K.
Also check scanning errors. Turns out even scanning of bytes.Buffer
can fail due to the line limit.
Currently the added test description leads to crashes:
--- FAIL: TestMinimizeRandom (0.12s)
prog_test.go:20: seed=1480014002950172453
panic: syscall syz_test$regression0: pointer arg 'f0' has output direction [recovered]
panic: syscall syz_test$regression0: pointer arg 'f0' has output direction
The description is OK. Fix that.
This allows to write:
string[salg_type, 14]
which will give a string buffer of size 14 regardless of actual string size.
Convert salg_type/salg_name to this.
