| Message ID | 1663679468-16757-1-git-send-email-zhaoyang.huang@unisoc.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC] mm: track bad page via kmemleak | expand |
(sorry, I missed this last month when it was posted) On Tue, Sep 20, 2022 at 09:11:08PM +0800, zhaoyang.huang wrote: > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > > Bad pages will failed go back to allocator and leaved as orphan pages, track > them down via kmemleak. > > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > --- > mm/page_alloc.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index e5486d4..24f682e 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1408,7 +1408,7 @@ static __always_inline bool free_pages_prepare(struct page *page, > __memcg_kmem_uncharge_page(page, order); > reset_page_owner(page, order); > page_table_check_free(page, order); > - return false; > + goto err; > } > > /* > @@ -1442,7 +1442,7 @@ static __always_inline bool free_pages_prepare(struct page *page, > if (check_free) > bad += check_free_page(page); > if (bad) > - return false; > + goto err; > > page_cpupid_reset_last(page); > page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; > @@ -1486,6 +1486,10 @@ static __always_inline bool free_pages_prepare(struct page *page, > debug_pagealloc_unmap_pages(page, 1 << order); > > return true; > +err: > + kmemleak_alloc(page_address(page), PAGE_SIZE << order, 1, GFP_KERNEL); > + return false; > + > } What's the aim of this tracking? First of all, that's a HWPoison page and it should note be touched, so the min_count should be -1 otherwise kmemleak will try to read it for references to other objects. Now, if all you need is a list of the bad pages, I don't think that's kmemleak's job. Maybe add them to a list and expose it somewhere else via debugfs.
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e5486d4..24f682e 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1408,7 +1408,7 @@ static __always_inline bool free_pages_prepare(struct page *page, __memcg_kmem_uncharge_page(page, order); reset_page_owner(page, order); page_table_check_free(page, order); - return false; + goto err; } /* @@ -1442,7 +1442,7 @@ static __always_inline bool free_pages_prepare(struct page *page, if (check_free) bad += check_free_page(page); if (bad) - return false; + goto err; page_cpupid_reset_last(page); page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; @@ -1486,6 +1486,10 @@ static __always_inline bool free_pages_prepare(struct page *page, debug_pagealloc_unmap_pages(page, 1 << order); return true; +err: + kmemleak_alloc(page_address(page), PAGE_SIZE << order, 1, GFP_KERNEL); + return false; + } #ifdef CONFIG_DEBUG_VM