40  * Returns 0 if mmiotrace is disabled, or if the fault is not
131 	 * If it was a exec (instruction fetch) fault on NX page, then  in is_prefetch()
132 	 * do not ignore the fault:  in is_prefetch()
216  *   Handle a fault on the vmalloc or module mapping area
227  *   unhandled page-fault when they are accessed.
410  * The OS sees this as a page fault with the upper 32bits of RIP cleared.
447  * We catch this in the page fault handler because these addresses
535 		pr_alert("BUG: unable to handle page fault for address: %px\n",  in show_fault_oops()
558 		 * contributory exception from user code and gets a page fault  in show_fault_oops()
559 		 * during delivery, the page fault can be delivered as though  in show_fault_oops()
647 	 * Stack overflow?  During boot, we can fault near the initial  in page_fault_oops()
658 		 * double-fault even before we get this far, in which case  in page_fault_oops()
659 		 * we're fine: the double-fault handler will deal with it.  in page_fault_oops()
662 		 * and then double-fault, though, because we're likely to  in page_fault_oops()
669 			      : "D" ("kernel stack overflow (page fault)"),  in page_fault_oops()
677 	 * Buggy firmware could access regions which might page fault.  If  in page_fault_oops()
718 	/* Are we prepared to handle this kernel fault? */  in kernelmode_fixup_or_oops()
721 		 * Any interrupt that takes a fault gets the fixup. This makes  in kernelmode_fixup_or_oops()
722 		 * the below recursive fault logic only apply to a faults from  in kernelmode_fixup_or_oops()
754 	 * AMD erratum #91 manifests as a spurious page fault on a PREFETCH  in kernelmode_fixup_or_oops()
824 	 * Valid to do another page fault here because this one came  in __bad_area_nosemaphore()
906 		 * A protection key fault means that the PKRU value did not allow  in bad_area_access_error()
913 		 * fault and that there was a VMA once we got in the fault  in bad_area_access_error()
921 		 * 5. T1   : enters fault handler, takes mmap_lock, etc...  in bad_area_access_error()
935 	  vm_fault_t fault)  in do_sigbus()  argument
944 	/* User-space => ok to do another page fault: */  in do_sigbus()
956 	if (fault & (VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE)) {  in do_sigbus()
961 	"MCE: Killing %s:%d due to hardware memory corruption fault at %lx\n",  in do_sigbus()
963 		if (fault & VM_FAULT_HWPOISON_LARGE)  in do_sigbus()
964 			lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));  in do_sigbus()
965 		if (fault & VM_FAULT_HWPOISON)  in do_sigbus()
986  * Handle a spurious fault caused by a stale TLB entry.
1001  * Returns non-zero if a spurious fault was handled, zero otherwise.
1084 	 * a follow-up action to resolve the fault, like a COW.  in access_error()
1093 	 * fix the cause of the fault.  Handle the fault as an access  in access_error()
1159 	 * We can fault-in kernel-space virtual memory on-demand. The  in do_kern_addr_fault()
1168 	 * fault is not any of the following:  in do_kern_addr_fault()
1169 	 * 1. A fault on a PTE with a reserved bit set.  in do_kern_addr_fault()
1170 	 * 2. A fault caused by a user-mode access.  (Do not demand-  in do_kern_addr_fault()
1171 	 *    fault kernel memory due to user-mode accesses).  in do_kern_addr_fault()
1172 	 * 3. A fault caused by a page-level protection violation.  in do_kern_addr_fault()
1173 	 *    (A demand fault would be on a non-present page which  in do_kern_addr_fault()
1191 	/* Was the fault spurious, caused by lazy TLB invalidation? */  in do_kern_addr_fault()
1202 	 * and handling kernel code that can fault, like get_user().  in do_kern_addr_fault()
1205 	 * fault we could otherwise deadlock:  in do_kern_addr_fault()
1227 	vm_fault_t fault;  in do_user_addr_fault()  local
1279 	 * in a region with pagefaults disabled then we must not take the fault  in do_user_addr_fault()
1288 	 * vmalloc fault has been handled.  in do_user_addr_fault()
1291 	 * potential system fault or CPU buglet:  in do_user_addr_fault()
1329 	 * tables.  But, an erroneous kernel fault occurring outside one of  in do_user_addr_fault()
1331 	 * to validate the fault against the address space.  in do_user_addr_fault()
1341 			 * Fault from code in kernel from  in do_user_addr_fault()
1385 	 * If for any reason at all we couldn't handle the fault,  in do_user_addr_fault()
1387 	 * the fault.  Since we never set FAULT_FLAG_RETRY_NOWAIT, if  in do_user_addr_fault()
1392 	 * repeat the page fault later with a VM_FAULT_NOPAGE retval  in do_user_addr_fault()
1397 	fault = handle_mm_fault(vma, address, flags, regs);  in do_user_addr_fault()
1399 	if (fault_signal_pending(fault, regs)) {  in do_user_addr_fault()
1416 	if (unlikely((fault & VM_FAULT_RETRY) &&  in do_user_addr_fault()
1423 	if (likely(!(fault & VM_FAULT_ERROR)))  in do_user_addr_fault()
1432 	if (fault & VM_FAULT_OOM) {  in do_user_addr_fault()
1443 		 * userspace (which will retry the fault, or kill us if we got  in do_user_addr_fault()
1448 		if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON|  in do_user_addr_fault()
1450 			do_sigbus(regs, error_code, address, fault);  in do_user_addr_fault()
1451 		else if (fault & VM_FAULT_SIGSEGV)  in do_user_addr_fault()
1481 	/* Was the fault on kernel-controlled part of the address space? */  in handle_page_fault()
1487 		 * User address page fault handling might have reenabled  in handle_page_fault()
1506 	 * (asynchronous page fault mechanism). The event happens when a  in DEFINE_IDTENTRY_RAW_ERRORCODE()
1531 	 * be invoked because a kernel fault on a user space address might  in DEFINE_IDTENTRY_RAW_ERRORCODE()
1534 	 * In case the fault hit a RCU idle region the conditional entry  in DEFINE_IDTENTRY_RAW_ERRORCODE()