kmemcheck: remove annotations

Patch series "kmemcheck: kill kmemcheck", v2.

As discussed at LSF/MM, kill kmemcheck.

KASan is a replacement that is able to work without the limitation of
kmemcheck (single CPU, slow).  KASan is already upstream.

We are also not aware of any users of kmemcheck (or users who don't
consider KASan as a suitable replacement).

The only objection was that since KASAN wasn't supported by all GCC
versions provided by distros at that time we should hold off for 2
years, and try again.

Now that 2 years have passed, and all distros provide gcc that supports
KASAN, kill kmemcheck again for the very same reasons.

This patch (of 4):

Remove kmemcheck annotations, and calls to kmemcheck from the kernel.

[alexander.levin@verizon.com: correctly remove kmemcheck call from dma_map_sg_attrs]
  Link: http://lkml.kernel.org/r/20171012192151.26531-1-alexander.levin@verizon.com
Link: http://lkml.kernel.org/r/20171007030159.22241-2-alexander.levin@verizon.com
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Hansen <devtimhansen@gmail.com>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 14 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e6106d7..30a464b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -24,7 +24,6 @@
 #include <linux/memblock.h>
 #include <linux/compiler.h>
 #include <linux/kernel.h>
-#include <linux/kmemcheck.h>
 #include <linux/kasan.h>
 #include <linux/module.h>
 #include <linux/suspend.h>
@@ -1013,7 +1012,6 @@ static __always_inline bool free_pages_prepare(struct page *page,
 	VM_BUG_ON_PAGE(PageTail(page), page);
 
 	trace_mm_page_free(page, order);
-	kmemcheck_free_shadow(page, order);
 
 	/*
 	 * Check tail pages before head page information is cleared to
@@ -2669,15 +2667,6 @@ void split_page(struct page *page, unsigned int order)
 	VM_BUG_ON_PAGE(PageCompound(page), page);
 	VM_BUG_ON_PAGE(!page_count(page), page);
 
-#ifdef CONFIG_KMEMCHECK
-	/*
-	 * Split shadow pages too, because free(page[0]) would
-	 * otherwise free the whole shadow.
-	 */
-	if (kmemcheck_page_is_tracked(page))
-		split_page(virt_to_page(page[0].shadow), order);
-#endif
-
 	for (i = 1; i < (1 << order); i++)
 		set_page_refcounted(page + i);
 	split_page_owner(page, order);
@@ -4223,9 +4212,6 @@ out:
 		page = NULL;
 	}
 
-	if (kmemcheck_enabled && page)
-		kmemcheck_pagealloc_alloc(page, order, gfp_mask);
-
 	trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
 
 	return page;