1 files changed, 18 insertions, 47 deletions

diff --git a/mm/page_poison.c b/mm/page_poison.c
index 34b9181ee5d1..3e9037363cf9 100644
--- a/mm/page_poison.c
+++ b/mm/page_poison.c
@@ -2,53 +2,35 @@
 #include <linux/kernel.h>
 #include <linux/string.h>
 #include <linux/mm.h>
+#include <linux/mmdebug.h>
 #include <linux/highmem.h>
-#include <linux/page_ext.h>
 #include <linux/poison.h>
 #include <linux/ratelimit.h>
 #include <linux/kasan.h>
 
-static bool want_page_poisoning __read_mostly;
+bool _page_poisoning_enabled_early;
+EXPORT_SYMBOL(_page_poisoning_enabled_early);
+DEFINE_STATIC_KEY_FALSE(_page_poisoning_enabled);
+EXPORT_SYMBOL(_page_poisoning_enabled);
 
 static int __init early_page_poison_param(char *buf)
 {
-	if (!buf)
-		return -EINVAL;
-	return strtobool(buf, &want_page_poisoning);
+	return kstrtobool(buf, &_page_poisoning_enabled_early);
 }
 early_param("page_poison", early_page_poison_param);
 
-/**
- * page_poisoning_enabled - check if page poisoning is enabled
- *
- * Return true if page poisoning is enabled, or false if not.
- */
-bool page_poisoning_enabled(void)
-{
-	/*
-	 * Assumes that debug_pagealloc_enabled is set before
-	 * memblock_free_all.
-	 * Page poisoning is debug page alloc for some arches. If
-	 * either of those options are enabled, enable poisoning.
-	 */
-	return (want_page_poisoning ||
-		(!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) &&
-		debug_pagealloc_enabled()));
-}
-EXPORT_SYMBOL_GPL(page_poisoning_enabled);
-
 static void poison_page(struct page *page)
 {
-	void *addr = kmap_atomic(page);
+	void *addr = kmap_local_page(page);
 
 	/* KASAN still think the page is in-use, so skip it. */
 	kasan_disable_current();
-	memset(addr, PAGE_POISON, PAGE_SIZE);
+	memset(kasan_reset_tag(addr), PAGE_POISON, PAGE_SIZE);
 	kasan_enable_current();
-	kunmap_atomic(addr);
+	kunmap_local(addr);
 }
 
-static void poison_pages(struct page *page, int n)
+void __kernel_poison_pages(struct page *page, int n)
 {
 	int i;
 
@@ -63,15 +45,12 @@ static bool single_bit_flip(unsigned char a, unsigned char b)
 	return error && !(error & (error - 1));
 }
 
-static void check_poison_mem(unsigned char *mem, size_t bytes)
+static void check_poison_mem(struct page *page, unsigned char *mem, size_t bytes)
 {
 	static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 10);
 	unsigned char *start;
 	unsigned char *end;
 
-	if (IS_ENABLED(CONFIG_PAGE_POISONING_NO_SANITY))
-		return;
-
 	start = memchr_inv(mem, PAGE_POISON, bytes);
 	if (!start)
 		return;
@@ -91,23 +70,26 @@ static void check_poison_mem(unsigned char *mem, size_t bytes)
 	print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1, start,
 			end - start + 1, 1);
 	dump_stack();
+	dump_page(page, "pagealloc: corrupted page details");
 }
 
 static void unpoison_page(struct page *page)
 {
 	void *addr;
 
-	addr = kmap_atomic(page);
+	addr = kmap_local_page(page);
+	kasan_disable_current();
 	/*
 	 * Page poisoning when enabled poisons each and every page
 	 * that is freed to buddy. Thus no extra check is done to
 	 * see if a page was poisoned.
 	 */
-	check_poison_mem(addr, PAGE_SIZE);
-	kunmap_atomic(addr);
+	check_poison_mem(page, kasan_reset_tag(addr), PAGE_SIZE);
+	kasan_enable_current();
+	kunmap_local(addr);
 }
 
-static void unpoison_pages(struct page *page, int n)
+void __kernel_unpoison_pages(struct page *page, int n)
 {
 	int i;
 
@@ -115,17 +97,6 @@ static void unpoison_pages(struct page *page, int n)
 		unpoison_page(page + i);
 }
 
-void kernel_poison_pages(struct page *page, int numpages, int enable)
-{
-	if (!page_poisoning_enabled())
-		return;
-
-	if (enable)
-		unpoison_pages(page, numpages);
-	else
-		poison_pages(page, numpages);
-}
-
 #ifndef CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC
 void __kernel_map_pages(struct page *page, int numpages, int enable)
 {