linux/arch/arm64/lib/uaccess_flushcache.c
Mark Rutland 9e94fdade4 arm64: uaccess: simplify __copy_user_flushcache()
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>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201202131558.39270-6-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-12-02 19:49:10 +00:00

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C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2017 ARM Ltd.
*/
#include <linux/uaccess.h>
#include <asm/barrier.h>
#include <asm/cacheflush.h>
void memcpy_flushcache(void *dst, const void *src, size_t cnt)
{
/*
* We assume this should not be called with @dst pointing to
* non-cacheable memory, such that we don't need an explicit
* barrier to order the cache maintenance against the memcpy.
*/
memcpy(dst, src, cnt);
__clean_dcache_area_pop(dst, cnt);
}
EXPORT_SYMBOL_GPL(memcpy_flushcache);
void memcpy_page_flushcache(char *to, struct page *page, size_t offset,
size_t len)
{
memcpy_flushcache(to, page_address(page) + offset, len);
}
unsigned long __copy_user_flushcache(void *to, const void __user *from,
unsigned long n)
{
unsigned long rc;
rc = raw_copy_from_user(to, from, n);
/* See above */
__clean_dcache_area_pop(to, n - rc);
return rc;
}