From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Tue, 16 Mar 2021 19:55:38 +0000 (-0400)
Subject: parisc: Fix cache rcu lock
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=2f5fbbfac15e3eb0f55d729962ff69ced9d77240;p=users%2Fjedix%2Flinux-maple.git

parisc: Fix cache rcu lock

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---

diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 288a25e1b1c2..edb8696612d0 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -522,8 +522,11 @@ static inline unsigned long mm_total_size(struct mm_struct *mm)
 	unsigned long usize = 0;
 	MA_STATE(mas, &mm->mm_mt, 0, 0);
 
+	rcu_read_lock();
 	mas_for_each(&mas, vma, ULONG_MAX)
 		usize += vma->vm_end - vma->vm_start;
+	rcu_read_unlock();
+
 	return usize;
 }
 
@@ -562,16 +565,19 @@ void flush_cache_mm(struct mm_struct *mm)
 	}
 
 	if (mm->context == mfsp(3)) {
+		rcu_read_lock();
 		mas_for_each(&mas, vma, ULONG_MAX) {
 			flush_user_dcache_range_asm(vma->vm_start, vma->vm_end);
 			if (vma->vm_flags & VM_EXEC)
 				flush_user_icache_range_asm(vma->vm_start, vma->vm_end);
 			flush_tlb_range(vma, vma->vm_start, vma->vm_end);
 		}
+		rcu_read_unlock();
 		return;
 	}
 
 	pgd = mm->pgd;
+	rcu_read_lock();
 	mas_for_each(&mas, vma, ULONG_MAX) {
 		unsigned long addr;
 
@@ -592,6 +598,7 @@ void flush_cache_mm(struct mm_struct *mm)
 			}
 		}
 	}
+	rcu_unread_lock();
 }
 
 void flush_cache_range(struct vm_area_struct *vma,