On Fri, 27 Apr 2018, Michal Hocko wrote: > On Thu 26-04-18 18:52:05, Mikulas Patocka wrote: > > > > > > On Fri, 27 Apr 2018, Michael S. Tsirkin wrote: > [...] > > > But assuming it's important to control this kind of > > > fault injection to be controlled from > > > a dedicated menuconfig option, why not the rest of > > > faults? > > > > The injected faults cause damage to the user, so there's no point to > > enable them by default. vmalloc fallback should not cause any damage > > (assuming that the code is correctly written). > > But you want to find those bugs which would BUG_ON easier, so there is a > risk of harm IIUC Yes, I want to harm them, but I only want to harm the users using the debugging kernel. Testers should be "harmed" by crashes - so that the users of production kernels are harmed less. If someone hits this, he should report it, use the kernel parameter to turn it off and continue with the testing. > and this is not much different than other fault injecting paths. Fault injections causes misbehavior even on completely bug-free code (for example, syscalls randomly returning -ENOMEM). This won't cause misbehavior on bug-free code. Mikulas
