ARM: cacheflush: don't bother rounding to nearest vma (97c72d89) · Commits · 戴 / test

do_cache_op finds the lowest VMA contained in the specified address range and rounds the range to cover only the mapped addresses. Since commit ("ARM: 7365/1: drop unused parameter from flush_cache_user_range") the VMA is not used for anything else in this code and seeing as the low-level cache flushing routines return -EFAULT if the address is not valid, there is no need for this range truncation. This patch removes the VMA handling code from the cacheflushing syscall. Signed-off-by:

Will Deacon <will.deacon@arm.com>

arch/arm/kernel/traps.c

+2 −15

Original line number	Diff line number	Diff line
		@@ -550,24 +550,11 @@ static long do_cache_op_restart(struct restart_block *unused)
		static inline int
		do_cache_op(unsigned long start, unsigned long end, int flags)
		{
		struct mm_struct *mm = current->active_mm;
		struct vm_area_struct *vma;

		if (end < start \|\| flags)
		return -EINVAL;

		down_read(&mm->mmap_sem);
		vma = find_vma(mm, start);
		if (!vma \|\| vma->vm_start >= end) {
		up_read(&mm->mmap_sem);
		return -EINVAL;
		}

		if (start < vma->vm_start)
		start = vma->vm_start;
		if (end > vma->vm_end)
		end = vma->vm_end;
		up_read(&mm->mmap_sem);
		if (!access_ok(VERIFY_READ, start, end - start))
		return -EFAULT;

		return __do_cache_op(start, end);
		}

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