[PATCH v2 8/9] mm: Remove CONFIG_PER_VMA_LOCK ifdefs

["Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>]

Provide lock_vma_under_rcu() when CONFIG_PER_VMA_LOCK is not defined
to eliminate ifdefs in the users.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 arch/arm64/mm/fault.c   | 2 --
 arch/powerpc/mm/fault.c | 4 ----
 arch/riscv/mm/fault.c   | 4 ----
 arch/s390/mm/fault.c    | 2 --
 arch/x86/mm/fault.c     | 4 ----
 include/linux/mm.h      | 6 ++++++
 6 files changed, 6 insertions(+), 16 deletions(-)

diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index b8c80f7b8a5f..2e5d1e238af9 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -587,7 +587,6 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
 
 	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
 
-#ifdef CONFIG_PER_VMA_LOCK
 	if (!(mm_flags & FAULT_FLAG_USER))
 		goto lock_mmap;
 
@@ -616,7 +615,6 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
 		return 0;
 	}
 lock_mmap:
-#endif /* CONFIG_PER_VMA_LOCK */
 
 retry:
 	vma = lock_mm_and_find_vma(mm, addr, regs);
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 82954d0e6906..b1723094d464 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -469,7 +469,6 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address,
 	if (is_exec)
 		flags |= FAULT_FLAG_INSTRUCTION;
 
-#ifdef CONFIG_PER_VMA_LOCK
 	if (!(flags & FAULT_FLAG_USER))
 		goto lock_mmap;
 
@@ -502,7 +501,6 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address,
 		return user_mode(regs) ? 0 : SIGBUS;
 
 lock_mmap:
-#endif /* CONFIG_PER_VMA_LOCK */
 
 	/* When running in the kernel we expect faults to occur only to
 	 * addresses in user space.  All other faults represent errors in the
@@ -552,9 +550,7 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address,
 
 	mmap_read_unlock(current->mm);
 
-#ifdef CONFIG_PER_VMA_LOCK
 done:
-#endif
 	if (unlikely(fault & VM_FAULT_ERROR))
 		return mm_fault_error(regs, address, fault);
 
diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index 6ea2cce4cc17..046732fcb48c 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -283,7 +283,6 @@ void handle_page_fault(struct pt_regs *regs)
 		flags |= FAULT_FLAG_WRITE;
 	else if (cause == EXC_INST_PAGE_FAULT)
 		flags |= FAULT_FLAG_INSTRUCTION;
-#ifdef CONFIG_PER_VMA_LOCK
 	if (!(flags & FAULT_FLAG_USER))
 		goto lock_mmap;
 
@@ -311,7 +310,6 @@ void handle_page_fault(struct pt_regs *regs)
 		return;
 	}
 lock_mmap:
-#endif /* CONFIG_PER_VMA_LOCK */
 
 retry:
 	vma = lock_mm_and_find_vma(mm, addr, regs);
@@ -368,9 +366,7 @@ void handle_page_fault(struct pt_regs *regs)
 
 	mmap_read_unlock(mm);
 
-#ifdef CONFIG_PER_VMA_LOCK
 done:
-#endif
 	if (unlikely(fault & VM_FAULT_ERROR)) {
 		tsk->thread.bad_cause = cause;
 		mm_fault_error(regs, addr, fault);
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 40a71063949b..ac8351f172bb 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -407,7 +407,6 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
 		access = VM_WRITE;
 	if (access == VM_WRITE)
 		flags |= FAULT_FLAG_WRITE;
-#ifdef CONFIG_PER_VMA_LOCK
 	if (!(flags & FAULT_FLAG_USER))
 		goto lock_mmap;
 	vma = lock_vma_under_rcu(mm, address);
@@ -431,7 +430,6 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
 		goto out;
 	}
 lock_mmap:
-#endif /* CONFIG_PER_VMA_LOCK */
 	mmap_read_lock(mm);
 
 	gmap = NULL;
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index b0f7add07aa5..ab778eac1952 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1350,7 +1350,6 @@ void do_user_addr_fault(struct pt_regs *regs,
 	}
 #endif
 
-#ifdef CONFIG_PER_VMA_LOCK
 	if (!(flags & FAULT_FLAG_USER))
 		goto lock_mmap;
 
@@ -1381,7 +1380,6 @@ void do_user_addr_fault(struct pt_regs *regs,
 		return;
 	}
 lock_mmap:
-#endif /* CONFIG_PER_VMA_LOCK */
 
 retry:
 	vma = lock_mm_and_find_vma(mm, address, regs);
@@ -1441,9 +1439,7 @@ void do_user_addr_fault(struct pt_regs *regs,
 	}
 
 	mmap_read_unlock(mm);
-#ifdef CONFIG_PER_VMA_LOCK
 done:
-#endif
 	if (likely(!(fault & VM_FAULT_ERROR)))
 		return;
 
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 46c442855df7..3c923a4bf213 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -813,6 +813,12 @@ static inline void assert_fault_locked(struct vm_fault *vmf)
 	mmap_assert_locked(vmf->vma->vm_mm);
 }
 
+static inline struct vm_area_struct *lock_vma_under_rcu(struct mm_struct *mm,
+		unsigned long address)
+{
+	return NULL;
+}
+
 #endif /* CONFIG_PER_VMA_LOCK */
 
 /*
-- 
2.39.2