[PATCH] coresight: tmc-etr: Check if page is valid before dma_map_page()

[Mathieu Poirier]

On Mon, Nov 23, 2020 at 10:46:56AM +0000, Suzuki K Poulose wrote:
> On 11/23/20 10:21 AM, Sai Prakash Ranjan wrote:
> > From: Mao Jinlong <jinlmao at codeaurora.org>
> > 
> > alloc_pages_node() return should be checked before calling
> > dma_map_page() to make sure that valid page is mapped or
> > else it can lead to aborts as below:
> > 
> >   Unable to handle kernel paging request at virtual address ffffffc008000000
> >   Mem abort info:
> >   <snip>...
> >   pc : __dma_inv_area+0x40/0x58
> >   lr : dma_direct_map_page+0xd8/0x1c8
> > 
> >   Call trace:
> >    __dma_inv_area
> >    tmc_pages_alloc
> >    tmc_alloc_data_pages
> >    tmc_alloc_sg_table
> >    tmc_init_etr_sg_table
> >    tmc_alloc_etr_buf
> >    tmc_enable_etr_sink_sysfs
> >    tmc_enable_etr_sink
> >    coresight_enable_path
> >    coresight_enable
> >    enable_source_store
> >    dev_attr_store
> >    sysfs_kf_write
> > 
> > Fixes: 99443ea19e8b ("coresight: Add generic TMC sg table framework")
> > Cc: stable at vger.kernel.org
> > Signed-off-by: Mao Jinlong <jinlmao at codeaurora.org>
> > Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan at codeaurora.org>
> 
> Reviewed-by: Suzuki K Poulose <suzuki.poulose at arm.com>
> 

Applied - thanks

Mathieu

> > ---
> >   drivers/hwtracing/coresight/coresight-tmc-etr.c | 2 ++
> >   1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> > index 525f0ecc129c..a31a4d7ae25e 100644
> > --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
> > +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> > @@ -217,6 +217,8 @@ static int tmc_pages_alloc(struct tmc_pages *tmc_pages,
> >   		} else {
> >   			page = alloc_pages_node(node,
> >   						GFP_KERNEL | __GFP_ZERO, 0);
> > +			if (!page)
> > +				goto err;
> >   		}
> >   		paddr = dma_map_page(real_dev, page, 0, PAGE_SIZE, dir);
> >   		if (dma_mapping_error(real_dev, paddr))
> > 
> > base-commit: c04e5d7bbf6f92a346d6b36770705e7f034df42d
> > 
>