From 06e929ccb9aa017a7e5a4bfbe47ca7d928f4a34e Mon Sep 17 00:00:00 2001 From: Olivier Moysan Date: Wed, 4 Dec 2019 16:43:32 +0100 Subject: [PATCH] ASoC: stm32: spdifrx: fix race condition in irq handler commit 86e1956af4c863d653136fd6e5694adf2054dbaa upstream. When snd_pcm_stop() is called in interrupt routine, substream context may have already been released. Add protection on substream context. Fixes: 03e4d5d56fa5 ("ASoC: stm32: Add SPDIFRX support") Signed-off-by: Olivier Moysan Link: https://lore.kernel.org/r/20191204154333.7152-3-olivier.moysan@st.com Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- sound/soc/stm/stm32_spdifrx.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) diff --git a/sound/soc/stm/stm32_spdifrx.c b/sound/soc/stm/stm32_spdifrx.c index ccb8a427..2f04cb6 100644 --- a/sound/soc/stm/stm32_spdifrx.c +++ b/sound/soc/stm/stm32_spdifrx.c @@ -220,6 +220,7 @@ * @slave_config: dma slave channel runtime config pointer * @phys_addr: SPDIFRX registers physical base address * @lock: synchronization enabling lock + * @irq_lock: prevent race condition with IRQ on stream state * @cs: channel status buffer * @ub: user data buffer * @irq: SPDIFRX interrupt line @@ -240,6 +241,7 @@ struct stm32_spdifrx_data { struct dma_slave_config slave_config; dma_addr_t phys_addr; spinlock_t lock; /* Sync enabling lock */ + spinlock_t irq_lock; /* Prevent race condition on stream state */ unsigned char cs[SPDIFRX_CS_BYTES_NB]; unsigned char ub[SPDIFRX_UB_BYTES_NB]; int irq; @@ -665,7 +667,6 @@ static const struct regmap_config stm32_h7_spdifrx_regmap_conf = { static irqreturn_t stm32_spdifrx_isr(int irq, void *devid) { struct stm32_spdifrx_data *spdifrx = (struct stm32_spdifrx_data *)devid; - struct snd_pcm_substream *substream = spdifrx->substream; struct platform_device *pdev = spdifrx->pdev; unsigned int cr, mask, sr, imr; unsigned int flags; @@ -733,14 +734,19 @@ static irqreturn_t stm32_spdifrx_isr(int irq, void *devid) regmap_update_bits(spdifrx->regmap, STM32_SPDIFRX_CR, SPDIFRX_CR_SPDIFEN_MASK, cr); - if (substream) - snd_pcm_stop(substream, SNDRV_PCM_STATE_DISCONNECTED); + spin_lock(&spdifrx->irq_lock); + if (spdifrx->substream) + snd_pcm_stop(spdifrx->substream, + SNDRV_PCM_STATE_DISCONNECTED); + spin_unlock(&spdifrx->irq_lock); return IRQ_HANDLED; } - if (err_xrun && substream) - snd_pcm_stop_xrun(substream); + spin_lock(&spdifrx->irq_lock); + if (err_xrun && spdifrx->substream) + snd_pcm_stop_xrun(spdifrx->substream); + spin_unlock(&spdifrx->irq_lock); return IRQ_HANDLED; } @@ -749,9 +755,12 @@ static int stm32_spdifrx_startup(struct snd_pcm_substream *substream, struct snd_soc_dai *cpu_dai) { struct stm32_spdifrx_data *spdifrx = snd_soc_dai_get_drvdata(cpu_dai); + unsigned long flags; int ret; + spin_lock_irqsave(&spdifrx->irq_lock, flags); spdifrx->substream = substream; + spin_unlock_irqrestore(&spdifrx->irq_lock, flags); ret = clk_prepare_enable(spdifrx->kclk); if (ret) @@ -827,8 +836,12 @@ static void stm32_spdifrx_shutdown(struct snd_pcm_substream *substream, struct snd_soc_dai *cpu_dai) { struct stm32_spdifrx_data *spdifrx = snd_soc_dai_get_drvdata(cpu_dai); + unsigned long flags; + spin_lock_irqsave(&spdifrx->irq_lock, flags); spdifrx->substream = NULL; + spin_unlock_irqrestore(&spdifrx->irq_lock, flags); + clk_disable_unprepare(spdifrx->kclk); } @@ -932,6 +945,7 @@ static int stm32_spdifrx_probe(struct platform_device *pdev) spdifrx->pdev = pdev; init_completion(&spdifrx->cs_completion); spin_lock_init(&spdifrx->lock); + spin_lock_init(&spdifrx->irq_lock); platform_set_drvdata(pdev, spdifrx); -- 2.7.4