| Message ID | 1402897251-23639-2-git-send-email-iamjoonsoo.kim@lge.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, Joonsoo On Mon, Jun 16, 2014 at 02:40:43PM +0900, Joonsoo Kim wrote: > We should free memory for bitmap when we find zone mis-match, > otherwise this memory will leak. > > Additionally, I copy code comment from PPC KVM's CMA code to inform > why we need to check zone mis-match. > > * Note > Minchan suggested to add a tag for the stable, but, I don't do it, > because I found this possibility during code-review and, IMO, > this patch isn't suitable for stable tree. Nice idea to put the comment in here. Thanks Joonsoo. It seems you obey "It must fix a real bug that bothers people" on Documentation/stable_kernel_rules.txt but it's a really obvious bug and hard to get a report from people because limited user and hard to detect small such small memory leak. In my experince, Andrew perfered stable marking for such a obvious problem but simple fix like this but not sure so let's pass the decision to him and will learn a lesson from him and will follow the decision from now on. Thanks. Acked-by: Minchan Kim <minchan@kernel.org> > > Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> > Reviewed-by: Michal Nazarewicz <mina86@mina86.com> > Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> > > diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c > index 83969f8..6467c91 100644 > --- a/drivers/base/dma-contiguous.c > +++ b/drivers/base/dma-contiguous.c > @@ -176,14 +176,24 @@ static int __init cma_activate_area(struct cma *cma) > base_pfn = pfn; > for (j = pageblock_nr_pages; j; --j, pfn++) { > WARN_ON_ONCE(!pfn_valid(pfn)); > + /* > + * alloc_contig_range requires the pfn range > + * specified to be in the same zone. Make this > + * simple by forcing the entire CMA resv range > + * to be in the same zone. > + */ > if (page_zone(pfn_to_page(pfn)) != zone) > - return -EINVAL; > + goto err; > } > init_cma_reserved_pageblock(pfn_to_page(base_pfn)); > } while (--i); > > mutex_init(&cma->lock); > return 0; > + > +err: > + kfree(cma->bitmap); > + return -EINVAL; > } > > static struct cma cma_areas[MAX_CMA_AREAS]; > -- > 1.7.9.5 > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
On Mon, Jun 16, 2014 at 03:27:19PM +0900, Minchan Kim wrote: > Hi, Joonsoo > > On Mon, Jun 16, 2014 at 02:40:43PM +0900, Joonsoo Kim wrote: > > We should free memory for bitmap when we find zone mis-match, > > otherwise this memory will leak. > > > > Additionally, I copy code comment from PPC KVM's CMA code to inform > > why we need to check zone mis-match. > > > > * Note > > Minchan suggested to add a tag for the stable, but, I don't do it, > > because I found this possibility during code-review and, IMO, > > this patch isn't suitable for stable tree. > > Nice idea to put the comment in here. Thanks Joonsoo. > > It seems you obey "It must fix a real bug that bothers people" > on Documentation/stable_kernel_rules.txt but it's a really obvious > bug and hard to get a report from people because limited user and > hard to detect small such small memory leak. > > In my experince, Andrew perfered stable marking for such a obvious > problem but simple fix like this but not sure so let's pass the decision > to him and will learn a lesson from him and will follow the decision > from now on. Yes, I intended to pass the decision to others. :) > > Thanks. > > Acked-by: Minchan Kim <minchan@kernel.org> Thanks.
diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c index 83969f8..6467c91 100644 --- a/drivers/base/dma-contiguous.c +++ b/drivers/base/dma-contiguous.c @@ -176,14 +176,24 @@ static int __init cma_activate_area(struct cma *cma) base_pfn = pfn; for (j = pageblock_nr_pages; j; --j, pfn++) { WARN_ON_ONCE(!pfn_valid(pfn)); + /* + * alloc_contig_range requires the pfn range + * specified to be in the same zone. Make this + * simple by forcing the entire CMA resv range + * to be in the same zone. + */ if (page_zone(pfn_to_page(pfn)) != zone) - return -EINVAL; + goto err; } init_cma_reserved_pageblock(pfn_to_page(base_pfn)); } while (--i); mutex_init(&cma->lock); return 0; + +err: + kfree(cma->bitmap); + return -EINVAL; } static struct cma cma_areas[MAX_CMA_AREAS];