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authorSasha Levin <sasha.levin@oracle.com>2014-01-23 15:52:54 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-23 16:36:50 -0800
commit309381feaee564281c3d9e90fbca8963bb7428ad (patch)
tree7e9f990c0cffcb8c5fc90deb1c7eac445c5ada0e /arch
parente3bba3c3c90cd434c1ccb9e5dc704a96baf9541c (diff)
downloadlinux-309381feaee564281c3d9e90fbca8963bb7428ad.tar.bz2
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/mm/gup.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c
index 0596e8e0cc19..207d9aef662d 100644
--- a/arch/x86/mm/gup.c
+++ b/arch/x86/mm/gup.c
@@ -108,8 +108,8 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr,
static inline void get_head_page_multiple(struct page *page, int nr)
{
- VM_BUG_ON(page != compound_head(page));
- VM_BUG_ON(page_count(page) == 0);
+ VM_BUG_ON_PAGE(page != compound_head(page), page);
+ VM_BUG_ON_PAGE(page_count(page) == 0, page);
atomic_add(nr, &page->_count);
SetPageReferenced(page);
}
@@ -135,7 +135,7 @@ static noinline int gup_huge_pmd(pmd_t pmd, unsigned long addr,
head = pte_page(pte);
page = head + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
do {
- VM_BUG_ON(compound_head(page) != head);
+ VM_BUG_ON_PAGE(compound_head(page) != head, page);
pages[*nr] = page;
if (PageTail(page))
get_huge_page_tail(page);
@@ -212,7 +212,7 @@ static noinline int gup_huge_pud(pud_t pud, unsigned long addr,
head = pte_page(pte);
page = head + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
do {
- VM_BUG_ON(compound_head(page) != head);
+ VM_BUG_ON_PAGE(compound_head(page) != head, page);
pages[*nr] = page;
if (PageTail(page))
get_huge_page_tail(page);