From: Guo Ren <ren_guo@xxxxxxxxx>
In our stress test, we found some crash problem caused by:
if (!(vma->vm_flags & VM_EXEC))
return;
in update_mmu_cache().
Seems current update_mmu_cache implementation is wrong and we retread
to the conservative implementation.
Also the usage of kmap_atomic in update_mmu_cache is risky, page-virtual
may be scheduled out and changed, so we must use preempt_disable &
pagefault_disable which is called by kmap_atomic().
Signed-off-by: Guo Ren <ren_guo@xxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/csky/abiv2/cacheflush.c | 13 ++-----------
1 file changed, 2 insertions(+), 11 deletions(-)
diff --git a/arch/csky/abiv2/cacheflush.c b/arch/csky/abiv2/cacheflush.c
index d22c95f..5bb887b 100644
--- a/arch/csky/abiv2/cacheflush.c
+++ b/arch/csky/abiv2/cacheflush.c
@@ -34,10 +34,6 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
{
unsigned long addr, pfn;
struct page *page;
- void *va;
-
- if (!(vma->vm_flags & VM_EXEC))
- return;
pfn = pte_pfn(*pte);
if (unlikely(!pfn_valid(pfn)))
@@ -47,14 +43,9 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
if (page == ZERO_PAGE(0))
return;
- va = page_address(page);
- addr = (unsigned long) va;
-
- if (va == NULL && PageHighMem(page))
- addr = (unsigned long) kmap_atomic(page);
+ addr = (unsigned long) kmap_atomic(page);
cache_wbinv_range(addr, addr + PAGE_SIZE);
- if (va == NULL && PageHighMem(page))
- kunmap_atomic((void *) addr);
+ kunmap_atomic((void *) addr);
}
--
2.7.4
