On Thu, 4 Feb 2021 07:25:55 +0000 HORIGUCHI NAOYA(堀口 直也) <[email protected]> wrote:
> Hi Aili, > > On Mon, Feb 01, 2021 at 04:17:49PM +0800, Aili Yao wrote: > > When one page is already hwpoisoned by AO action, process may not be > > killed, the process mapping this page may make a syscall include this > > page and result to trigger a VM_FAULT_HWPOISON fault, if it's in kernel > > mode it may be fixed by fixup_exception. Current code will just return > > error code to user process. > > > > This is not sufficient, we should send a SIGBUS to the process and log > > the info to console, as we can't trust the process will handle the error > > correctly. > > > > Suggested-by: Feng Yang <[email protected]> > > Signed-off-by: Aili Yao <[email protected]> > > --- > ... > > > @@ -662,12 +662,32 @@ no_context(struct pt_regs *regs, unsigned long > > error_code, > > * In this case we need to make sure we're not recursively > > * faulting through the emulate_vsyscall() logic. > > */ > > + > > + if (IS_ENABLED(CONFIG_MEMORY_FAILURE) && > > + fault & (VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE)) { > > + unsigned int lsb = 0; > > + > > + pr_err("MCE: Killing %s:%d due to hardware memory > > corruption fault at %lx\n", > > + current->comm, current->pid, address); > > + > > + sanitize_error_code(address, &error_code); > > + set_signal_archinfo(address, error_code); > > + > > + if (fault & VM_FAULT_HWPOISON_LARGE) > > + lsb = > > hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault)); > > + if (fault & VM_FAULT_HWPOISON) > > + lsb = PAGE_SHIFT; > > + > > + force_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, > > lsb); > > This part contains some duplicated code with do_sigbus(), so some refactoring > (like > adding a common function) would be more helpful. Yes, agree, I will modify this and rebase to the big fault series from tip. Thanks Aili Yao
