[merged mm-stable] s390-mm-accelerate-pagefault-when-badaccess.patch removed from -mm tree

[merged mm-stable] s390-mm-accelerate-pagefault-when-badaccess.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: s390: mm: accelerate pagefault when badaccess
has been removed from the -mm tree.  Its filename was
     s390-mm-accelerate-pagefault-when-badaccess.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Kefeng Wang <wangkefeng.wang@huawei.com>
Subject: s390: mm: accelerate pagefault when badaccess
Date: Wed, 3 Apr 2024 16:38:04 +0800

The vm_flags of vma already checked under per-VMA lock, if it is a bad
access, directly handle error, no need to retry with mmap_lock again. 
Since the page faut is handled under per-VMA lock, count it as a vma lock
event with VMA_LOCK_SUCCESS.

Link: https://lkml.kernel.org/r/20240403083805.1818160-7-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/s390/mm/fault.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/s390/mm/fault.c~s390-mm-accelerate-pagefault-when-badaccess
+++ a/arch/s390/mm/fault.c
@@ -325,7 +325,8 @@ static void do_exception(struct pt_regs
 		goto lock_mmap;
 	if (!(vma->vm_flags & access)) {
 		vma_end_read(vma);
-		goto lock_mmap;
+		count_vm_vma_lock_event(VMA_LOCK_SUCCESS);
+		return handle_fault_error_nolock(regs, SEGV_ACCERR);
 	}
 	fault = handle_mm_fault(vma, address, flags | FAULT_FLAG_VMA_LOCK, regs);
 	if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED)))
_

Patches currently in -mm which might be from wangkefeng.wang@huawei.com are

arm64-mm-drop-vm_fault_badmap-vm_fault_badaccess.patch
arm-mm-drop-vm_fault_badmap-vm_fault_badaccess.patch
mm-move-mm-counter-updating-out-of-set_pte_range.patch
mm-filemap-batch-mm-counter-updating-in-filemap_map_pages.patch
mm-swapfile-check-usable-swap-device-in-__folio_throttle_swaprate.patch
mm-memory-check-userfaultfd_wp-in-vmf_orig_pte_uffd_wp.patch