mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGE

Most of the VM_BUG_ON assertions are performed on a page.  Usually, when
one of these assertions fails we'll get a BUG_ON with a call stack and
the registers.

I've recently noticed based on the requests to add a small piece of code
that dumps the page to various VM_BUG_ON sites that the page dump is
quite useful to people debugging issues in mm.

This patch adds a VM_BUG_ON_PAGE(cond, page) which beyond doing what
VM_BUG_ON() does, also dumps the page before executing the actual
BUG_ON.

[akpm@linux-foundation.org: fix up includes]
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 8 deletions

diff --git a/mm/swap_state.c b/mm/swap_state.c
index e6f15f8ca2af..98e85e9c2b2d 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -83,9 +83,9 @@ int __add_to_swap_cache(struct page *page, swp_entry_t entry)
         int error;
         struct address_space *address_space;
 
-        VM_BUG_ON(!PageLocked(page));
-        VM_BUG_ON(PageSwapCache(page));
-        VM_BUG_ON(!PageSwapBacked(page));
+        VM_BUG_ON_PAGE(!PageLocked(page), page);
+        VM_BUG_ON_PAGE(PageSwapCache(page), page);
+        VM_BUG_ON_PAGE(!PageSwapBacked(page), page);
 
         page_cache_get(page);
         SetPageSwapCache(page);
@@ -139,9 +139,9 @@ void __delete_from_swap_cache(struct page *page)
         swp_entry_t entry;
         struct address_space *address_space;
 
-        VM_BUG_ON(!PageLocked(page));
-        VM_BUG_ON(!PageSwapCache(page));
-        VM_BUG_ON(PageWriteback(page));
+        VM_BUG_ON_PAGE(!PageLocked(page), page);
+        VM_BUG_ON_PAGE(!PageSwapCache(page), page);
+        VM_BUG_ON_PAGE(PageWriteback(page), page);
 
         entry.val = page_private(page);
         address_space = swap_address_space(entry);
@@ -165,8 +165,8 @@ int add_to_swap(struct page *page, struct list_head *list)
         swp_entry_t entry;
         int err;
 
-        VM_BUG_ON(!PageLocked(page));
-        VM_BUG_ON(!PageUptodate(page));
+        VM_BUG_ON_PAGE(!PageLocked(page), page);
+        VM_BUG_ON_PAGE(!PageUptodate(page), page);
 
         entry = get_swap_page();
         if (!entry.val)