Commit ef3a1632 authored by ZhangPeng's avatar ZhangPeng Committed by Ma Wupeng
Browse files

userswap: introduce new flag to determine the first page fault 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I6CAIM



--------------------------------

Introduce new flag to determine the first page fault.

Signed-off-by: default avatarZhangPeng <zhangpeng362@huawei.com>
parent 010932f5

fs/userfaultfd.c

+4 −0
Original line number Diff line number Diff line
@@ -485,6 +485,10 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason) 
	uwq.wq.private = current;

	uwq.msg = userfault_msg(vmf->address, vmf->flags, reason,

			ctx->features);

#ifdef CONFIG_USERSWAP

	if (reason & VM_USWAP && pte_none(vmf->orig_pte))

		uwq.msg.arg.pagefault.flags |= UFFD_PAGEFAULT_FLAG_FPF;

#endif

	uwq.ctx = ctx;

	uwq.waken = false;

include/linux/userswap.h

+7 −0
Original line number Diff line number Diff line
@@ -59,6 +59,13 @@ static inline bool uswap_vm_flag_bug_on(unsigned long reason) 
	return !(reason & VM_UFFD_MISSING) ^ !!(reason & VM_UFFD_WP);

}



static inline bool uswap_missing(struct vm_area_struct *vma)

{

	if (vma->vm_flags & VM_USWAP && vma->vm_flags & VM_UFFD_MISSING)

		return true;

	return false;

}



#endif /* CONFIG_USERSWAP */



#endif /* _LINUX_USERSWAP_H */

include/uapi/linux/userfaultfd.h

+1 −0
Original line number Diff line number Diff line
@@ -127,6 +127,7 @@ struct uffd_msg { 
/* flags for UFFD_EVENT_PAGEFAULT */

#define UFFD_PAGEFAULT_FLAG_WRITE	(1<<0)	/* If this was a write fault */

#define UFFD_PAGEFAULT_FLAG_WP		(1<<1)	/* If reason is VM_UFFD_WP */

#define UFFD_PAGEFAULT_FLAG_FPF		(1<<10) /* If this was the first page fault */



struct uffdio_api {

	/* userland asks for an API number and the features to enable */

mm/memory.c

+14 −0
Original line number Diff line number Diff line
@@ -73,6 +73,7 @@ 
#include <linux/perf_event.h>

#include <linux/ptrace.h>

#include <linux/vmalloc.h>

#include <linux/userswap.h>



#include <trace/events/kmem.h>
@@ -3689,6 +3690,12 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf) 
		if (ret)

			goto unlock;

		/* Deliver the page fault to userland, check inside PT lock */

#ifdef CONFIG_USERSWAP

		if (uswap_missing(vma)) {

			pte_unmap_unlock(vmf->pte, vmf->ptl);

			return handle_userfault(vmf, VM_UFFD_MISSING|VM_USWAP);

		}

#endif

		if (userfaultfd_missing(vma)) {

			pte_unmap_unlock(vmf->pte, vmf->ptl);

			return handle_userfault(vmf, VM_UFFD_MISSING);
@@ -3731,6 +3738,13 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf) 
		goto release;



	/* Deliver the page fault to userland, check inside PT lock */

#ifdef CONFIG_USERSWAP

	if (uswap_missing(vma)) {

		pte_unmap_unlock(vmf->pte, vmf->ptl);

		put_page(page);

		return handle_userfault(vmf, VM_UFFD_MISSING | VM_USWAP);

	}

#endif

	if (userfaultfd_missing(vma)) {

		pte_unmap_unlock(vmf->pte, vmf->ptl);

		put_page(page);