[PATCH 1/4] mm: cma: Don't crash on allocation if CMA area can't be activated
From: Michal Nazarewicz <hidden>
Date: 2014-10-23 16:53:45
Also in:
linux-mm, linux-sh, lkml
On Thu, Oct 23 2014, Laurent Pinchart wrote:
If activation of the CMA area fails its mutex won't be initialized, leading to an oops at allocation time when trying to lock the mutex. Fix this by failing allocation if the area hasn't been successfully actived, and detect that condition by moving the CMA bitmap allocation after page block reservation completion. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Cc: <redacted> # v3.17 Acked-by: Michal Nazarewicz <redacted> As a matter of fact, this is present in kernels earlier than 3.17 but in the 3.17 the code has been moved from drivers/base/dma-contiguous.c to mm/cma.c so this might require separate stable patch. I can track this and prepare a patch if you want.
quoted hunk ↗ jump to hunk
--- mm/cma.c | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-)diff --git a/mm/cma.c b/mm/cma.c index 963bc4a..16c6650 100644 --- a/mm/cma.c +++ b/mm/cma.c@@ -93,11 +93,6 @@ static int __init cma_activate_area(struct cma *cma) unsigned i = cma->count >> pageblock_order; struct zone *zone; - cma->bitmap = kzalloc(bitmap_size, GFP_KERNEL); - - if (!cma->bitmap) - return -ENOMEM; - WARN_ON_ONCE(!pfn_valid(pfn)); zone = page_zone(pfn_to_page(pfn));@@ -114,17 +109,17 @@ static int __init cma_activate_area(struct cma *cma) * to be in the same zone. */ if (page_zone(pfn_to_page(pfn)) != zone) - goto err; + return -EINVAL; } init_cma_reserved_pageblock(pfn_to_page(base_pfn)); } while (--i); + cma->bitmap = kzalloc(bitmap_size, GFP_KERNEL); + if (!cma->bitmap) + return -ENOMEM; + mutex_init(&cma->lock); return 0; - -err: - kfree(cma->bitmap); - return -EINVAL; } static int __init cma_init_reserved_areas(void)@@ -313,7 +308,7 @@ struct page *cma_alloc(struct cma *cma, int count, unsigned int align) struct page *page = NULL; int ret; - if (!cma || !cma->count) + if (!cma || !cma->count || !cma->bitmap) return NULL; pr_debug("%s(cma %p, count %d, align %d)\n", __func__, (void *)cma,-- 2.0.4
-- Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o ..o | Computer Science, Micha? ?mina86? Nazarewicz (o o) ooo +--[off-list ref]--<xmpp:mina86@jabber.org>--ooO--(_)--Ooo--