Messages in this thread | | | Date | Fri, 8 Mar 2019 09:01:11 -0600 | From | Josh Poimboeuf <> | Subject | Re: [PATCH 18/20] objtool: Add UACCESS validation |
| |
On Thu, Mar 07, 2019 at 08:03:13PM +0100, Peter Zijlstra wrote: > On Thu, Mar 07, 2019 at 07:48:13PM +0100, Peter Zijlstra wrote: > > On Thu, Mar 07, 2019 at 09:54:14AM -0800, Linus Torvalds wrote: > > > On Thu, Mar 7, 2019 at 9:41 AM Peter Zijlstra <peterz@infradead.org> wrote: > > > > > > > > > > What's the call site that made you go "just add __memset() to the list"? > > > > > > > > __asan_{,un}poinson_stack_memory() > > > > kasan_{,un}poison_shadow() > > > > __memset() > > > > > > Ugh. I think I almost just agree with your decision to just let that > > > memset go unchecked. > > > > > > I'm not saying it's right, but it doesn't seem to be a fight worth fighting. > > > > One think I could do; is add a filter to each function and only allow > > __memset from the kasan code, and not from anywhere else. > > Ah.. how about I feed objtool a text file with all these symbol names; > and I have Makefile compose file that from fragments. > > Then only KASAN builds will have memset whitelisted, and any other build > will still flag memset abuse. > > Now I only have to figure out how to make Makefile do something like > that :-)
Instead of adding all those additional moving parts, I would much rather either:
a) have kasan call a special whitelisted version of memset (like hpa suggested); or
b) just don't use the objtool --uaccess flag for KASAN builds.
-- Josh
| |