From: Hyeonggon Yoo <42.hyeyoo@gmail.com>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>,
Christoph Lameter <cl@linux.com>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Pekka Enberg <penberg@kernel.org>,
linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
patches@lists.linux.dev
Subject: Re: [PATCH v2 24/33] mm/slob: Convert SLOB to use struct slab
Date: Fri, 10 Dec 2021 10:44:35 +0000 [thread overview]
Message-ID: <20211210104435.GA632117@odroid> (raw)
In-Reply-To: <20211201181510.18784-25-vbabka@suse.cz>
On Wed, Dec 01, 2021 at 07:15:01PM +0100, Vlastimil Babka wrote:
> From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
>
> Use struct slab throughout the slob allocator.
>
> [ vbabka@suse.cz: don't introduce wrappers for PageSlobFree in mm/slab.h just
> for the single callers being wrappers in mm/slob.c ]
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
> ---
> mm/slob.c | 34 +++++++++++++++++-----------------
> 1 file changed, 17 insertions(+), 17 deletions(-)
>
> diff --git a/mm/slob.c b/mm/slob.c
> index d2d15e7f191c..d3512bcc3141 100644
> --- a/mm/slob.c
> +++ b/mm/slob.c
...
> /* Enough room on this page? */
> @@ -358,8 +358,8 @@ static void *slob_alloc(size_t size, gfp_t gfp, int align, int node,
> b = slob_new_pages(gfp & ~__GFP_ZERO, 0, node);
> if (!b)
> return NULL;
> - sp = virt_to_page(b);
> - __SetPageSlab(sp);
> + sp = virt_to_slab(b);
> + __SetPageSlab(slab_page(sp));
Hello Vlastimil.
I've tested this patch on my machine and it causes NULL pointer dereference.
that's because virt_to_slab returns NULL if folio_test_slab is false.
and __SetPageSlab is called with sp = NULL.
diff below fixed bug.
diff --git a/mm/slob.c b/mm/slob.c
index d3512bcc3141..cf669f03440f 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -358,8 +358,8 @@ static void *slob_alloc(size_t size, gfp_t gfp, int a
lign, int node,
b = slob_new_pages(gfp & ~__GFP_ZERO, 0, node);
if (!b)
return NULL;
+ __SetPageSlab(virt_to_page(b));
sp = virt_to_slab(b);
- __SetPageSlab(slab_page(sp));
spin_lock_irqsave(&slob_lock, flags);
sp->units = SLOB_UNITS(PAGE_SIZE);
Thanks,
Hyeonggon.
>
> spin_lock_irqsave(&slob_lock, flags);
> sp->units = SLOB_UNITS(PAGE_SIZE);
> @@ -381,7 +381,7 @@ static void *slob_alloc(size_t size, gfp_t gfp, int align, int node,
> */
> static void slob_free(void *block, int size)
> {
> - struct page *sp;
> + struct slab *sp;
> slob_t *prev, *next, *b = (slob_t *)block;
> slobidx_t units;
> unsigned long flags;
> @@ -391,7 +391,7 @@ static void slob_free(void *block, int size)
> return;
> BUG_ON(!size);
>
> - sp = virt_to_page(block);
> + sp = virt_to_slab(block);
> units = SLOB_UNITS(size);
>
> spin_lock_irqsave(&slob_lock, flags);
> @@ -401,8 +401,8 @@ static void slob_free(void *block, int size)
> if (slob_page_free(sp))
> clear_slob_page_free(sp);
> spin_unlock_irqrestore(&slob_lock, flags);
> - __ClearPageSlab(sp);
> - page_mapcount_reset(sp);
> + __ClearPageSlab(slab_page(sp));
> + page_mapcount_reset(slab_page(sp));
> slob_free_pages(b, 0);
> return;
> }
> --
> 2.33.1
>
>
next prev parent reply other threads:[~2021-12-10 10:45 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-01 18:14 [PATCH v2 00/33] Separate struct slab from struct page Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 01/33] mm: add virt_to_folio() and folio_address() Vlastimil Babka
2021-12-14 14:20 ` Johannes Weiner
2021-12-14 14:27 ` Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 02/33] mm/slab: Dissolve slab_map_pages() in its caller Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 03/33] mm/slub: Make object_err() static Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 04/33] mm: Split slab into its own type Vlastimil Babka
2021-12-14 14:24 ` Johannes Weiner
2021-12-01 18:14 ` [PATCH v2 05/33] mm: Add account_slab() and unaccount_slab() Vlastimil Babka
2021-12-14 14:25 ` Johannes Weiner
2021-12-01 18:14 ` [PATCH v2 06/33] mm: Convert virt_to_cache() to use struct slab Vlastimil Babka
2021-12-14 14:26 ` Johannes Weiner
2021-12-01 18:14 ` [PATCH v2 07/33] mm: Convert __ksize() to " Vlastimil Babka
2021-12-14 14:28 ` Johannes Weiner
2021-12-01 18:14 ` [PATCH v2 08/33] mm: Use struct slab in kmem_obj_info() Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 09/33] mm: Convert check_heap_object() to use struct slab Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 10/33] mm/slub: Convert detached_freelist to use a " Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 11/33] mm/slub: Convert kfree() " Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 12/33] mm/slub: Convert __slab_lock() and __slab_unlock() to " Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 13/33] mm/slub: Convert print_page_info() to print_slab_info() Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 14/33] mm/slub: Convert alloc_slab_page() to return a struct slab Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 15/33] mm/slub: Convert __free_slab() to use " Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 16/33] mm/slub: Convert pfmemalloc_match() to take a " Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 17/33] mm/slub: Convert most struct page to struct slab by spatch Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 18/33] mm/slub: Finish struct page to struct slab conversion Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 19/33] mm/slab: Convert kmem_getpages() and kmem_freepages() to struct slab Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 20/33] mm/slab: Convert most struct page to struct slab by spatch Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 21/33] mm/slab: Finish struct page to struct slab conversion Vlastimil Babka
2021-12-01 18:14 ` [PATCH v2 22/33] mm: Convert struct page to struct slab in functions used by other subsystems Vlastimil Babka
2021-12-02 17:16 ` Andrey Konovalov
2021-12-14 14:31 ` Johannes Weiner
2021-12-01 18:15 ` [PATCH v2 23/33] mm/memcg: Convert slab objcgs from struct page to struct slab Vlastimil Babka
2021-12-14 14:43 ` Johannes Weiner
2021-12-20 23:31 ` Vlastimil Babka
2021-12-01 18:15 ` [PATCH v2 24/33] mm/slob: Convert SLOB to use " Vlastimil Babka
2021-12-10 10:44 ` Hyeonggon Yoo [this message]
2021-12-10 11:44 ` Vlastimil Babka
2021-12-10 15:29 ` Hyeonggon Yoo
2021-12-10 18:09 ` Vlastimil Babka
2021-12-11 10:54 ` Hyeonggon Yoo
2021-12-01 18:15 ` [PATCH v2 25/33] mm/kasan: Convert to struct folio and " Vlastimil Babka
2021-12-02 17:16 ` Andrey Konovalov
2021-12-01 18:15 ` [PATCH v2 26/33] mm/kfence: Convert kfence_guarded_alloc() to " Vlastimil Babka
2021-12-01 18:15 ` [PATCH v2 27/33] zsmalloc: Stop using slab fields in struct page Vlastimil Babka
2021-12-01 23:34 ` Minchan Kim
2021-12-14 14:58 ` Johannes Weiner
2021-12-01 18:15 ` [PATCH v2 28/33] bootmem: Use page->index instead of page->freelist Vlastimil Babka
2021-12-14 14:59 ` Johannes Weiner
2021-12-01 18:15 ` [PATCH v2 29/33] iommu: Use put_pages_list Vlastimil Babka
2021-12-01 19:07 ` Matthew Wilcox
2021-12-01 19:45 ` Robin Murphy
2021-12-01 18:15 ` [PATCH v2 30/33] mm: Remove slab from struct page Vlastimil Babka
2021-12-14 14:46 ` Johannes Weiner
2021-12-01 18:15 ` [PATCH v2 31/33] mm/sl*b: Differentiate struct slab fields by sl*b implementations Vlastimil Babka
[not found] ` <20211210163757.GA717823@odroid>
2021-12-10 18:26 ` Vlastimil Babka
2021-12-11 16:23 ` Matthew Wilcox
[not found] ` <20211211115527.GA822127@odroid>
2021-12-11 16:52 ` Matthew Wilcox
2021-12-01 18:15 ` [PATCH v2 32/33] mm/slub: Simplify struct slab slabs field definition Vlastimil Babka
2021-12-14 15:06 ` Johannes Weiner
2021-12-01 18:15 ` [PATCH v2 33/33] mm/slub: Define struct slab fields for CONFIG_SLUB_CPU_PARTIAL only when enabled Vlastimil Babka
2021-12-01 18:39 ` slab tree for next Vlastimil Babka
2021-12-01 20:34 ` Vlastimil Babka
2021-12-02 16:36 ` Vlastimil Babka
2021-12-02 20:39 ` Stephen Rothwell
2022-01-04 0:21 ` Vlastimil Babka
2022-01-04 8:44 ` Stephen Rothwell
2023-08-29 9:55 ` Vlastimil Babka
2023-08-29 21:33 ` Stephen Rothwell
2024-11-05 16:33 ` Vlastimil Babka
2024-11-05 21:08 ` Stephen Rothwell
2021-12-02 12:25 ` [PATCH v2 00/33] Separate struct slab from struct page Vlastimil Babka
2021-12-14 12:57 ` Vlastimil Babka
[not found] ` <20211214143822.GA1063445@odroid>
2021-12-14 14:43 ` Vlastimil Babka
2021-12-15 1:03 ` Roman Gushchin
2021-12-15 23:38 ` Roman Gushchin
2021-12-16 9:19 ` Vlastimil Babka
2021-12-20 0:47 ` Vlastimil Babka
2021-12-20 1:42 ` Matthew Wilcox
2021-12-20 0:24 ` Vlastimil Babka
2021-12-16 15:00 ` Hyeonggon Yoo
2021-12-20 23:58 ` Vlastimil Babka
2021-12-21 17:25 ` Robin Murphy
2021-12-22 7:36 ` Hyeonggon Yoo
2021-12-22 16:56 ` Vlastimil Babka
2021-12-25 9:16 ` Hyeonggon Yoo
2021-12-25 17:53 ` Matthew Wilcox
2021-12-27 2:43 ` Hyeonggon Yoo
2021-12-29 11:22 ` Hyeonggon Yoo
2022-01-03 17:56 ` Vlastimil Babka
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