> -----Original Message----- > From: Darren Hart [mailto:dvhart@xxxxxxxxxxxxx] > Sent: Wednesday, June 20, 2018 7:17 PM > To: Kees Cook > Cc: LKML; Andy Shevchenko; Platform Driver; Mihai Donțu; Limonciello, Mario > Subject: Re: [PATCH] platform/x86: wmi: Do not mix pages and kmalloc > > On Wed, Jun 20, 2018 at 04:43:14PM -0700, Kees Cook wrote: > > On Wed, Jun 20, 2018 at 4:37 PM, Darren Hart <dvhart@xxxxxxxxxxxxx> wrote: > > > On Wed, Jun 20, 2018 at 02:31:41PM -0700, Kees Cook wrote: > > >> The probe handler_data was being allocated with __get_free_pages() > > >> for no reason I could find. The error path was using kfree(). Since > > > > > > v4 of Mario's series used kmalloc: > > > https://patchwork.kernel.org/patch/9985827/ > > > > > > This was changed in v10 to use __get_free_pages: > > > https://patchwork.kernel.org/patch/10018023/ > > > > > > But... I'm not finding the discussion that led to this change.... Mario, > > > do you recall? Something about contiguous memory? We had a similar > > > discussion on an earlier series: > > > > > > https://patchwork.kernel.org/patch/9975277/ > > > > FWIW, kmalloc gets you contiguous memory... > > Yeah, I'm not finding a valid reason to use __get_free_pages over kmalloc in > this case. I'll give Mario a chance to respond in case I'm just missing > something, but otherwise will plan to apply this patch. I think it was for contiguous memory, so if kmalloc is giving that I agree no need to keep __get_free_pages instead. Acked-by: Mario Limonciello <Mario.limonciello@xxxxxxxx> Thanks, > > > > > But if the reason is found and needs to stay, the probe error path's > > kfree() needs to be fixed, and __GFP_COMP needs to be added to the > > free page flags. > > Got it, thanks Kees. > > -- > Darren Hart > VMware Open Source Technology Center
