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Commit 115b2247 authored by Catalin Marinas's avatar Catalin Marinas Committed by Russell King
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ARM: 5794/1: Flush the D-cache during copy_user_highpage() 



The I and D caches for copy-on-write pages on processors with
write-allocate caches become incoherent causing problems on application
relying on CoW for text pages (dynamic linker relocating symbols in a
text page). This patch flushes the D-cache for such pages.

Cc: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent f91fb05d

arch/arm/mm/copypage-v6.c

+8 −0
Original line number Original line Diff line number Diff line
@@ -41,6 +41,14 @@ static void v6_copy_user_highpage_nonaliasing(struct page *to, 
	kfrom = kmap_atomic(from, KM_USER0);

	kfrom = kmap_atomic(from, KM_USER0);

	kto = kmap_atomic(to, KM_USER1);

	kto = kmap_atomic(to, KM_USER1);

	copy_page(kto, kfrom);

	copy_page(kto, kfrom);

#ifdef CONFIG_HIGHMEM

	/*

	 * kmap_atomic() doesn't set the page virtual address, and

	 * kunmap_atomic() takes care of cache flushing already.

	 */

	if (page_address(to) != NULL)

#endif

		__cpuc_flush_dcache_page(kto);

	kunmap_atomic(kto, KM_USER1);

	kunmap_atomic(kto, KM_USER1);

	kunmap_atomic(kfrom, KM_USER0);

	kunmap_atomic(kfrom, KM_USER0);

}

}