Messages in this thread | | | Date | Thu, 29 Jan 2015 15:26:08 -0800 | From | Dave Hansen <> | Subject | Re: [PATCH 0/3]: x86, fpu: unlazy_fpu fixes/cleanups |
| |
On 01/29/2015 01:56 PM, Oleg Nesterov wrote: > --- x/arch/x86/kernel/traps.c > +++ x/arch/x86/kernel/traps.c > @@ -313,7 +313,7 @@ dotraplinkage void do_bounds(struct pt_r > * It is not directly accessible, though, so we need to > * do an xsave and then pull it out of the xsave buffer. > */ > - fpu_save_init(&tsk->thread.fpu); > + unlazy_fpu(tsk); > xsave_buf = &(tsk->thread.fpu.state->xsave); ... > bndcsr = get_xsave_addr(xsave_buf, XSTATE_BNDCSR);
Hmm, if the the thread was not using the FPU, and this fails to save anything in to the xsave_buf, what will bndcsr point to? It _looks_ to me like it will just point to uninitialized data since the xsave never happened.
Fenghua, shouldn't get_xsave_addr() be checking the xstate bit against the xsave->xstate_bv?
| |