csky: Fixup wrong update_mmu_cache implementation (981bbf27) · Commits · 戴 / test

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@c-sky.com> Cc: Arnd Bergmann <arnd@arndb.de>

arch/csky/abiv2/cacheflush.c

+2 −11

Original line number	Diff line number	Diff line
		@@ -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);

		cache_wbinv_range(addr, addr + PAGE_SIZE);

		if (va == NULL && PageHighMem(page))
		kunmap_atomic((void *) addr);
		}

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