On Tue, 9 Mar 2021 10:14:52 +0800
Aili Yao [off-list ref] wrote:

On Mon, 8 Mar 2021 18:31:07 +0000
"Luck, Tony" [off-list ref] wrote:

quoted

quoted

Can you point me at that SIGBUS code in a current kernel?    

It is in kill_me_maybe().  mce_vaddr is setup when we disassemble whatever get_user()
or copy from user variant was in use in the kernel when the poison memory was consumed.

        if (p->mce_vaddr != (void __user *)-1l) {
                force_sig_mceerr(BUS_MCEERR_AR, p->mce_vaddr, PAGE_SHIFT);

Would it be any better if we used the BUS_MCEERR_AO code that goes into siginfo?

That would make it match up better with what happens when poison is found
asynchronously by the patrol scrubber. I.e. the semantics are:

AR: You just touched poison at this address and need to do something about that.
AO: Just letting you know that you have some poison at the address in siginfo.

-Tony  

Is the kill action for this scenario in memory_failure()?

Does the current logic kill the process twice for this scenario ?
I am confused.

-- 
Thanks!
Aili Yao