Messages in this thread | | | Date | Wed, 22 Jan 2020 22:29:44 +0300 | From | Cyrill Gorcunov <> | Subject | Re: [PATCH] x86/pkeys: add check for pkey "overflow" |
| |
On Wed, Jan 22, 2020 at 11:09:47AM -0800, Dave Hansen wrote: > On 1/22/20 10:51 AM, Cyrill Gorcunov wrote: > >> + /* > >> + * This code should only be called with valid 'pkey' > >> + * values originating from in-kernel users. Complain > >> + * if a bad value is observed. > >> + */ > >> + WARN_ON_ONCE(pkey >= arch_max_pkey()); > > > Should not we rather abort this operation and exit with EINVAL > > or something similar instead of calling wrmsr with overflowed > > value? IOW, > > > > if (pkey >= arch_max_pkey()) { > > WARN_ON_ONCE(1); > > return -EINVAL; > > } > > I don't feel strongly about it. The reason I didn't do that is to > minimize the chance that this would cause any functional regression.
OK, I don't mind leaving just WARN_ON_ONCE.
> > It's not a huge chance, but I've certainly fat-fingered my share of > off-by-one bugs.
Heh :)
| |