Unverified Commit adf610d3 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
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!5734 arch/mm/fault: accelerate pagefault when badaccess 

Merge Pull Request from: @ci-robot 
 
PR sync from: Peng Zhang <zhangpeng362@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/SJR62DX4OYAPUTIXSVBEXYEZH3CDOOQZ/ 
From: ZhangPeng <zhangpeng362@huawei.com>

Backport arch/mm/fault: accelerate pagefault when badaccess.

A test from lmbench shows 34% improve after this changes on
arm64:
  lat_sig -P 1 prot lat_sig 0.29194 -> 0.19198

Kefeng Wang (2):
  arm64: mm: accelerate pagefault when VM_FAULT_BADACCESS
  x86: mm: accelerate pagefault when badaccess


-- 
2.25.1
 
https://gitee.com/openeuler/kernel/issues/I9E07B 
 
Link:https://gitee.com/openeuler/kernel/pulls/5734

 

Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parents 5cf97fd1 5fafc438

arch/arm64/mm/fault.c

+3 −1
Original line number Diff line number Diff line
@@ -622,7 +622,9 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr, 


	if (!(vma->vm_flags & vm_flags)) {

		vma_end_read(vma);

		goto lock_mmap;

		fault = VM_FAULT_BADACCESS;

		count_vm_vma_lock_event(VMA_LOCK_SUCCESS);

		goto done;

	}

	fault = handle_mm_fault(vma, addr, mm_flags | FAULT_FLAG_VMA_LOCK, regs);

	if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED)))

arch/x86/mm/fault.c

+14 −9
Original line number Diff line number Diff line
@@ -868,14 +868,17 @@ bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code, 


static void

__bad_area(struct pt_regs *regs, unsigned long error_code,

	   unsigned long address, u32 pkey, int si_code)

	   unsigned long address, struct mm_struct *mm,

	   struct vm_area_struct *vma, u32 pkey, int si_code)

{

	struct mm_struct *mm = current->mm;

	/*

	 * Something tried to access memory that isn't in our memory map..

	 * Fix it, but check if it's kernel or user first..

	 */

	if (mm)

		mmap_read_unlock(mm);

	else

		vma_end_read(vma);



	__bad_area_nosemaphore(regs, error_code, address, pkey, si_code);

}
@@ -899,7 +902,8 @@ static inline bool bad_area_access_from_pkeys(unsigned long error_code, 


static noinline void

bad_area_access_error(struct pt_regs *regs, unsigned long error_code,

		      unsigned long address, struct vm_area_struct *vma)

		      unsigned long address, struct mm_struct *mm,

		      struct vm_area_struct *vma)

{

	/*

	 * This OSPKE check is not strictly necessary at runtime.
@@ -929,9 +933,9 @@ bad_area_access_error(struct pt_regs *regs, unsigned long error_code, 
		 */

		u32 pkey = vma_pkey(vma);



		__bad_area(regs, error_code, address, pkey, SEGV_PKUERR);

		__bad_area(regs, error_code, address, mm, vma, pkey, SEGV_PKUERR);

	} else {

		__bad_area(regs, error_code, address, 0, SEGV_ACCERR);

		__bad_area(regs, error_code, address, mm, vma, 0, SEGV_ACCERR);

	}

}
@@ -1358,8 +1362,9 @@ void do_user_addr_fault(struct pt_regs *regs, 
		goto lock_mmap;



	if (unlikely(access_error(error_code, vma))) {

		vma_end_read(vma);

		goto lock_mmap;

		bad_area_access_error(regs, error_code, address, NULL, vma);

		count_vm_vma_lock_event(VMA_LOCK_SUCCESS);

		return;

	}

	fault = handle_mm_fault(vma, address, flags | FAULT_FLAG_VMA_LOCK, regs);

	if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED)))
@@ -1395,7 +1400,7 @@ void do_user_addr_fault(struct pt_regs *regs, 
	 * we can handle it..

	 */

	if (unlikely(access_error(error_code, vma))) {

		bad_area_access_error(regs, error_code, address, vma);

		bad_area_access_error(regs, error_code, address, mm, vma);

		return;

	}