Re: [Xen-devel] [PATCH v2 10/13] fuzz/x86_emulate: Make input more compact

2017-10-05 Thread Jan Beulich
>>> On 05.10.17 at 17:04, wrote: > On 10/04/2017 09:26 AM, Jan Beulich wrote: > On 25.09.17 at 16:26, wrote: >>> --- a/tools/fuzz/x86_instruction_emulator/fuzz-emul.c >>> +++ b/tools/fuzz/x86_instruction_emulator/fuzz-emul.c >>> @@ -53,6 +53,15 @@ struct fuzz_state >>> }; >>> #define DATA_O

Re: [Xen-devel] [PATCH v2 10/13] fuzz/x86_emulate: Make input more compact

2017-10-05 Thread George Dunlap
On 10/04/2017 09:26 AM, Jan Beulich wrote: On 25.09.17 at 16:26, wrote: >> @@ -22,13 +25,17 @@ int main(int argc, char **argv) >> setbuf(stdin, NULL); >> setbuf(stdout, NULL); >> >> +opt_compact = true; > > How about giving the variable an initializer instead? Actually, if w

Re: [Xen-devel] [PATCH v2 10/13] fuzz/x86_emulate: Make input more compact

2017-10-04 Thread Jan Beulich
>>> On 25.09.17 at 16:26, wrote: > @@ -22,13 +25,17 @@ int main(int argc, char **argv) > setbuf(stdin, NULL); > setbuf(stdout, NULL); > > +opt_compact = true; How about giving the variable an initializer instead? > --- a/tools/fuzz/x86_instruction_emulator/fuzz-emul.c > +++ b/too

[Xen-devel] [PATCH v2 10/13] fuzz/x86_emulate: Make input more compact

2017-09-25 Thread George Dunlap
At the moment, AFL reckons that for any given input, 87% of it is completely irrelevant: that is, it can change it as much as it wants but have no impact on the result of the test; and yet it can't remove it. This is largely because we interpret the blob handed to us as a large struct, including C