[PATCH 2/3] ARM: cacheflush: don't bother rounding to nearest vma

Will Deacon
2013-03-25T18:18:05Z

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 4542b6a0fa6b ("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 | 17 +----------------
1 file changed, 1 insertion(+), 16 deletions(-)

diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 1c08911..da5e268 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -509,25 +509,10 @@ static int bad_syscall(int n, struct pt_regs *regs)
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) {
- if (start < vma->vm_start)
- start = vma->vm_start;
- if (end > vma->vm_end)
- end = vma->vm_end;
-
- up_read(&mm->mmap_sem);
- return flush_cache_user_range(start, end);
- }
- up_read(&mm->mmap_sem);
- return -EINVAL;
+ return flush_cache_user_range(start, end);
}

/*
--
1.8.0