| Message ID | 20220817101826.236819-18-42.hyeyoo@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | common kmalloc v4 | expand |
On 8/17/22 12:18, Hyeonggon Yoo wrote: > If address of large object is not beginning of folio or size of > the folio is too small, it must be invalid. BUG() in such cases. > > Cc: Marco Elver <elver@google.com> > Suggested-by: Vlastimil Babka <vbabka@suse.cz> > Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> > Reviewed-by: Vlastimil Babka <vbabka@suse.cz> > --- > mm/slab_common.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/mm/slab_common.c b/mm/slab_common.c > index 9c273a5fb0d7..98d029212682 100644 > --- a/mm/slab_common.c > +++ b/mm/slab_common.c > @@ -984,8 +984,11 @@ size_t __ksize(const void *object) > > folio = virt_to_folio(object); > > - if (unlikely(!folio_test_slab(folio))) > + if (unlikely(!folio_test_slab(folio))) { > + BUG_ON(folio_size(folio) <= KMALLOC_MAX_CACHE_SIZE); > + BUG_ON(object != folio_address(folio)); > return folio_size(folio); > + } > > return slab_ksize(folio_slab(folio)->slab_cache); > } In light of latest Linus' rant on BUG_ON() [1] I'm changing it to WARN_ON and return 0, as it was in v3. [1] https://lore.kernel.org/all/CAHk-=wiEAH+ojSpAgx_Ep=NKPWHU8AdO3V56BXcCsU97oYJ1EA@mail.gmail.com/ diff --git a/mm/slab_common.c b/mm/slab_common.c index 98d029212682..a80c3a5e194d 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -985,8 +985,10 @@ size_t __ksize(const void *object) folio = virt_to_folio(object); if (unlikely(!folio_test_slab(folio))) { - BUG_ON(folio_size(folio) <= KMALLOC_MAX_CACHE_SIZE); - BUG_ON(object != folio_address(folio)); + if (WARN_ON(folio_size(folio) <= KMALLOC_MAX_CACHE_SIZE)) + return 0; + if (WARN_ON(object != folio_address(folio))) + return 0; return folio_size(folio); }
On Tue, Aug 23, 2022 at 05:12:01PM +0200, Vlastimil Babka wrote: > On 8/17/22 12:18, Hyeonggon Yoo wrote: > > If address of large object is not beginning of folio or size of > > the folio is too small, it must be invalid. BUG() in such cases. > > > > Cc: Marco Elver <elver@google.com> > > Suggested-by: Vlastimil Babka <vbabka@suse.cz> > > Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> > > Reviewed-by: Vlastimil Babka <vbabka@suse.cz> > > --- > > mm/slab_common.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/mm/slab_common.c b/mm/slab_common.c > > index 9c273a5fb0d7..98d029212682 100644 > > --- a/mm/slab_common.c > > +++ b/mm/slab_common.c > > @@ -984,8 +984,11 @@ size_t __ksize(const void *object) > > > > folio = virt_to_folio(object); > > > > - if (unlikely(!folio_test_slab(folio))) > > + if (unlikely(!folio_test_slab(folio))) { > > + BUG_ON(folio_size(folio) <= KMALLOC_MAX_CACHE_SIZE); > > + BUG_ON(object != folio_address(folio)); > > return folio_size(folio); > > + } > > > > return slab_ksize(folio_slab(folio)->slab_cache); > > } > > In light of latest Linus' rant on BUG_ON() [1] I'm changing it to WARN_ON > and return 0, as it was in v3. > > [1] https://lore.kernel.org/all/CAHk-=wiEAH+ojSpAgx_Ep=NKPWHU8AdO3V56BXcCsU97oYJ1EA@mail.gmail.com/ Okay. I'm fine with that. > > > diff --git a/mm/slab_common.c b/mm/slab_common.c > index 98d029212682..a80c3a5e194d 100644 > --- a/mm/slab_common.c > +++ b/mm/slab_common.c > @@ -985,8 +985,10 @@ size_t __ksize(const void *object) > folio = virt_to_folio(object); > > if (unlikely(!folio_test_slab(folio))) { > - BUG_ON(folio_size(folio) <= KMALLOC_MAX_CACHE_SIZE); > - BUG_ON(object != folio_address(folio)); > + if (WARN_ON(folio_size(folio) <= KMALLOC_MAX_CACHE_SIZE)) > + return 0; > + if (WARN_ON(object != folio_address(folio))) > + return 0; > return folio_size(folio); > } > >
diff --git a/mm/slab_common.c b/mm/slab_common.c index 9c273a5fb0d7..98d029212682 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -984,8 +984,11 @@ size_t __ksize(const void *object) folio = virt_to_folio(object); - if (unlikely(!folio_test_slab(folio))) + if (unlikely(!folio_test_slab(folio))) { + BUG_ON(folio_size(folio) <= KMALLOC_MAX_CACHE_SIZE); + BUG_ON(object != folio_address(folio)); return folio_size(folio); + } return slab_ksize(folio_slab(folio)->slab_cache); }