From af19b7ce76ba220f358c82b0a5e7d68909a23aa5 Mon Sep 17 00:00:00 2001 From: Stefan Wahren Date: Sun, 11 Nov 2018 21:23:56 +0100 Subject: [PATCH] mmc: bcm2835: Avoid possible races on data requests There are two accesses on the data requests which are not protected by the mutex. So fix this accordingly. Signed-off-by: Stefan Wahren Acked-by: Eric Anholt Signed-off-by: Ulf Hansson --- drivers/mmc/host/bcm2835.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c index 0711e251940c..cdfc24f1093b 100644 --- a/drivers/mmc/host/bcm2835.c +++ b/drivers/mmc/host/bcm2835.c @@ -1053,10 +1053,12 @@ static void bcm2835_dma_complete_work(struct work_struct *work) { struct bcm2835_host *host = container_of(work, struct bcm2835_host, dma_work); - struct mmc_data *data = host->data; + struct mmc_data *data; mutex_lock(&host->mutex); + data = host->data; + if (host->dma_chan) { dma_unmap_sg(host->dma_chan->device->dev, data->sg, data->sg_len, @@ -1181,9 +1183,6 @@ static void bcm2835_request(struct mmc_host *mmc, struct mmc_request *mrq) return; } - if (host->use_dma && mrq->data && (mrq->data->blocks > PIO_THRESHOLD)) - bcm2835_prepare_dma(host, mrq->data); - mutex_lock(&host->mutex); WARN_ON(host->mrq); @@ -1207,6 +1206,9 @@ static void bcm2835_request(struct mmc_host *mmc, struct mmc_request *mrq) return; } + if (host->use_dma && mrq->data && (mrq->data->blocks > PIO_THRESHOLD)) + bcm2835_prepare_dma(host, mrq->data); + host->use_sbc = !!mrq->sbc && host->mrq->data && (host->mrq->data->flags & MMC_DATA_READ); if (host->use_sbc) { -- 2.11.0