[PATCHv3 10/17] arm64: uaccess: simplify __copy_user_flushcache()

Mark Rutland
2020-10-26T13:37:13Z

Currently __copy_user_flushcache() open-codes raw_copy_from_user(), and
doesn't use uaccess_mask_ptr() on the user address. Let's have it call
raw_copy_from_user(), which is both a simplification and ensures that
user pointers are masked under speculation.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will@kernel.org>
---
arch/arm64/lib/uaccess_flushcache.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/arm64/lib/uaccess_flushcache.c b/arch/arm64/lib/uaccess_flushcache.c
index bfa30b75b2b8e..c83bb5a4aad2c 100644
--- a/arch/arm64/lib/uaccess_flushcache.c
+++ b/arch/arm64/lib/uaccess_flushcache.c
@@ -30,9 +30,7 @@ unsigned long __copy_user_flushcache(void *to, const void __user *from,
{
unsigned long rc;

- uaccess_enable_not_uao();
- rc = __arch_copy_from_user(to, from, n);
- uaccess_disable_not_uao();
+ rc = raw_copy_from_user(to, from, n);

/* See above */
__clean_dcache_area_pop(to, n - rc);