Messages in this thread | | | Date | Wed, 15 Jan 2020 14:27:54 -0800 | From | "Luck, Tony" <> | Subject | Re: [PATCH v11] x86/split_lock: Enable split lock detection by kernel |
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On Mon, Jan 13, 2020 at 09:55:21PM -0800, Sean Christopherson wrote: > On Fri, Jan 10, 2020 at 11:24:09AM -0800, Luck, Tony wrote:
All comments accepted and code changed ... except for these three:
> > +#define TIF_SLD 18 /* split_lock_detect */ > > A more informative name comment would be helpful since the flag is set when > SLD is disabled by the previous task. Something like? > > #define TIF_NEED_SLD_RESTORE 18 /* Restore split lock detection on context switch */
That name is more informative ... but it is also really, really long. Are you sure?
> > +bool handle_user_split_lock(struct pt_regs *regs, long error_code) > > +{ > > + if ((regs->flags & X86_EFLAGS_AC) || sld_state == sld_fatal) > > + return false; > > Maybe add "|| WARN_ON_ONCE(sld_state != sld_off)" to try to prevent the > kernel from going fully into the weeds if a spurious #AC occurs.
Can a spurious #AC occur? I don't see how.
> > @@ -242,7 +243,6 @@ do_trap(int trapnr, int signr, char *str, struct pt_regs *regs, > > { > > struct task_struct *tsk = current; > > > > - > > Whitespace. > > > if (!do_trap_no_signal(tsk, trapnr, str, regs, error_code)) > > return;
I'm staring at the post patch code, and I can't see what whitespace issue you see.
-Tony
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