kmemcheck: rip it out

Fix up makefiles, remove references, and git rm kmemcheck.

Link: http://lkml.kernel.org/r/20171007030159.22241-4-alexander.levin@verizon.com
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Tim Hansen <devtimhansen@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 2 insertions, 131 deletions

diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
index 5b0adf1435de..e5e606ee5f71 100644
--- a/mm/Kconfig.debug
+++ b/mm/Kconfig.debug
@@ -11,7 +11,6 @@ config DEBUG_PAGEALLOC
 	bool "Debug page memory allocations"
 	depends on DEBUG_KERNEL
 	depends on !HIBERNATION || ARCH_SUPPORTS_DEBUG_PAGEALLOC && !PPC && !SPARC
-	depends on !KMEMCHECK
 	select PAGE_EXTENSION
 	select PAGE_POISONING if !ARCH_SUPPORTS_DEBUG_PAGEALLOC
 	---help---
diff --git a/mm/Makefile b/mm/Makefile
index 4659b93cba43..e7ebd176fb93 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -17,7 +17,6 @@ KCOV_INSTRUMENT_slub.o := n
 KCOV_INSTRUMENT_page_alloc.o := n
 KCOV_INSTRUMENT_debug-pagealloc.o := n
 KCOV_INSTRUMENT_kmemleak.o := n
-KCOV_INSTRUMENT_kmemcheck.o := n
 KCOV_INSTRUMENT_memcontrol.o := n
 KCOV_INSTRUMENT_mmzone.o := n
 KCOV_INSTRUMENT_vmstat.o := n
@@ -70,7 +69,6 @@ obj-$(CONFIG_KSM) += ksm.o
 obj-$(CONFIG_PAGE_POISONING) += page_poison.o
 obj-$(CONFIG_SLAB) += slab.o
 obj-$(CONFIG_SLUB) += slub.o
-obj-$(CONFIG_KMEMCHECK) += kmemcheck.o
 obj-$(CONFIG_KASAN)	+= kasan/
 obj-$(CONFIG_FAILSLAB) += failslab.o
 obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o
diff --git a/mm/kmemcheck.c b/mm/kmemcheck.c
index b3a4d61d341c..cec594032515 100644
--- a/mm/kmemcheck.c
+++ b/mm/kmemcheck.c
@@ -1,126 +1 @@
 // SPDX-License-Identifier: GPL-2.0
-#include <linux/gfp.h>
-#include <linux/mm_types.h>
-#include <linux/mm.h>
-#include <linux/slab.h>
-#include "slab.h"
-#include <linux/kmemcheck.h>
-
-void kmemcheck_alloc_shadow(struct page *page, int order, gfp_t flags, int node)
-{
-	struct page *shadow;
-	int pages;
-	int i;
-
-	pages = 1 << order;
-
-	/*
-	 * With kmemcheck enabled, we need to allocate a memory area for the
-	 * shadow bits as well.
-	 */
-	shadow = alloc_pages_node(node, flags, order);
-	if (!shadow) {
-		if (printk_ratelimit())
-			pr_err("kmemcheck: failed to allocate shadow bitmap\n");
-		return;
-	}
-
-	for(i = 0; i < pages; ++i)
-		page[i].shadow = page_address(&shadow[i]);
-
-	/*
-	 * Mark it as non-present for the MMU so that our accesses to
-	 * this memory will trigger a page fault and let us analyze
-	 * the memory accesses.
-	 */
-	kmemcheck_hide_pages(page, pages);
-}
-
-void kmemcheck_free_shadow(struct page *page, int order)
-{
-	struct page *shadow;
-	int pages;
-	int i;
-
-	if (!kmemcheck_page_is_tracked(page))
-		return;
-
-	pages = 1 << order;
-
-	kmemcheck_show_pages(page, pages);
-
-	shadow = virt_to_page(page[0].shadow);
-
-	for(i = 0; i < pages; ++i)
-		page[i].shadow = NULL;
-
-	__free_pages(shadow, order);
-}
-
-void kmemcheck_slab_alloc(struct kmem_cache *s, gfp_t gfpflags, void *object,
-			  size_t size)
-{
-	if (unlikely(!object)) /* Skip object if allocation failed */
-		return;
-
-	/*
-	 * Has already been memset(), which initializes the shadow for us
-	 * as well.
-	 */
-	if (gfpflags & __GFP_ZERO)
-		return;
-
-	/* No need to initialize the shadow of a non-tracked slab. */
-	if (s->flags & SLAB_NOTRACK)
-		return;
-
-	if (!kmemcheck_enabled || gfpflags & __GFP_NOTRACK) {
-		/*
-		 * Allow notracked objects to be allocated from
-		 * tracked caches. Note however that these objects
-		 * will still get page faults on access, they just
-		 * won't ever be flagged as uninitialized. If page
-		 * faults are not acceptable, the slab cache itself
-		 * should be marked NOTRACK.
-		 */
-		kmemcheck_mark_initialized(object, size);
-	} else if (!s->ctor) {
-		/*
-		 * New objects should be marked uninitialized before
-		 * they're returned to the called.
-		 */
-		kmemcheck_mark_uninitialized(object, size);
-	}
-}
-
-void kmemcheck_slab_free(struct kmem_cache *s, void *object, size_t size)
-{
-	/* TODO: RCU freeing is unsupported for now; hide false positives. */
-	if (!s->ctor && !(s->flags & SLAB_TYPESAFE_BY_RCU))
-		kmemcheck_mark_freed(object, size);
-}
-
-void kmemcheck_pagealloc_alloc(struct page *page, unsigned int order,
-			       gfp_t gfpflags)
-{
-	int pages;
-
-	if (gfpflags & (__GFP_HIGHMEM | __GFP_NOTRACK))
-		return;
-
-	pages = 1 << order;
-
-	/*
-	 * NOTE: We choose to track GFP_ZERO pages too; in fact, they
-	 * can become uninitialized by copying uninitialized memory
-	 * into them.
-	 */
-
-	/* XXX: Can use zone->node for node? */
-	kmemcheck_alloc_shadow(page, order, gfpflags, -1);
-
-	if (gfpflags & __GFP_ZERO)
-		kmemcheck_mark_initialized_pages(page, pages);
-	else
-		kmemcheck_mark_uninitialized_pages(page, pages);
-}
diff --git a/mm/slub.c b/mm/slub.c
index c2c41e178acf..cfd56e5a35fb 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1371,7 +1371,7 @@ static inline void *slab_free_hook(struct kmem_cache *s, void *x)
 	 * So in order to make the debug calls that expect irqs to be
 	 * disabled we need to disable interrupts temporarily.
 	 */
-#if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP)
+#ifdef CONFIG_LOCKDEP
 	{
 		unsigned long flags;
 
@@ -1399,8 +1399,7 @@ static inline void slab_free_freelist_hook(struct kmem_cache *s,
  * Compiler cannot detect this function can be removed if slab_free_hook()
  * evaluates to nothing.  Thus, catch all relevant config debug options here.
  */
-#if defined(CONFIG_KMEMCHECK) ||		\
-	defined(CONFIG_LOCKDEP)	||		\
+#if defined(CONFIG_LOCKDEP)	||		\
 	defined(CONFIG_DEBUG_KMEMLEAK) ||	\
 	defined(CONFIG_DEBUG_OBJECTS_FREE) ||	\
 	defined(CONFIG_KASAN)