Re: [PATCH] x86/sgx: fix a NULL pointer

[Huang, Kai]

On Fri, 2023-07-21 at 00:32 +0000, Huang, Kai wrote:
> On Wed, 2023-07-19 at 08:53 -0500, Haitao Huang wrote:
> > Hi Dave and Kai
> > On Tue, 18 Jul 2023 19:21:54 -0500, Dave Hansen <dave.hansen@xxxxxxxxx>  
> > wrote:
> > 
> > > On 7/18/23 17:14, Huang, Kai wrote:
> > > > Also perhaps the patch title is too vague.  Adding more information  
> > > > doesn't hurt
> > > > I think, e.g., mentioning it is a fix for NULL pointer dereference in  
> > > > the EAUG
> > > > flow.
> > > 
> > > Yeah, let's say something like:
> > > 
> > > 	x86/sgx: Resolve SECS reclaim vs. page fault race
> > > 
> > The patch is not to resolve SECS vs #PF race though the race is a  
> > necessary condition to cause the NULL pointer. The same condition does not  
> > cause NULL pointer in the ELDU path of #PF, only in EAUG path of #PF.
> > 
> > And the issue really is the NULL pointer not checked and fix was to reuse  
> > the same code to reload SECS in ELDU code path for EAUG code path
> > 
> > 
> > How about this:
> > 
> > x86/sgx:  Reload reclaimed SECS for EAUG on #PF
> > 
> > or
> > 
> > x86/sgx: Fix a NULL pointer to SECS used for EAUG on #PF
> > 
> 
> Perhaps you can add "EAUG" part to what Dave suggested?
> 
> 	x86/sgx: Resolves SECS reclaim vs. page fault race on EAUG
> 
> (assuming Dave is fine with this :-))

Btw, do you have a real call trace?  If you have, I think you can add that to
the changelog too because that catches people's eye immediately.