[PATCH v3 11/11] s390/mm: Convert to LOCK_MM_AND_FIND_VMA

[Claudio Imbrenda <imbrenda@linux.ibm.com>]

From: Heiko Carstens <hca@linux.ibm.com>

With the gmap code gone s390 can be easily converted to
LOCK_MM_AND_FIND_VMA like it has been done for most other
architectures.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
---
 arch/s390/Kconfig    |  1 +
 arch/s390/mm/fault.c | 13 ++-----------
 2 files changed, 3 insertions(+), 11 deletions(-)

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index d339fe4fdedf..8109446f7b24 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -224,6 +224,7 @@ config S390
 	select HAVE_VIRT_CPU_ACCOUNTING_IDLE
 	select IOMMU_HELPER		if PCI
 	select IOMMU_SUPPORT		if PCI
+	select LOCK_MM_AND_FIND_VMA
 	select MMU_GATHER_MERGE_VMAS
 	select MMU_GATHER_NO_GATHER
 	select MMU_GATHER_RCU_TABLE_FREE
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 93ae097ef0e0..8bd2b8d64273 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -308,18 +308,10 @@ static void do_exception(struct pt_regs *regs, int access)
 		return;
 	}
 lock_mmap:
-	mmap_read_lock(mm);
 retry:
-	vma = find_vma(mm, address);
+	vma = lock_mm_and_find_vma(mm, address, regs);
 	if (!vma)
-		return handle_fault_error(regs, SEGV_MAPERR);
-	if (unlikely(vma->vm_start > address)) {
-		if (!(vma->vm_flags & VM_GROWSDOWN))
-			return handle_fault_error(regs, SEGV_MAPERR);
-		vma = expand_stack(mm, address);
-		if (!vma)
-			return handle_fault_error_nolock(regs, SEGV_MAPERR);
-	}
+		return handle_fault_error_nolock(regs, SEGV_MAPERR);
 	if (unlikely(!(vma->vm_flags & access)))
 		return handle_fault_error(regs, SEGV_ACCERR);
 	fault = handle_mm_fault(vma, address, flags, regs);
@@ -337,7 +329,6 @@ static void do_exception(struct pt_regs *regs, int access)
 	}
 	if (fault & VM_FAULT_RETRY) {
 		flags |= FAULT_FLAG_TRIED;
-		mmap_read_lock(mm);
 		goto retry;
 	}
 	mmap_read_unlock(mm);
-- 
2.47.0