[PATCH AUTOSEL 4.9 03/10] mmc: mediatek: fix race condition between msdc_request_timeout and irq

[PATCH AUTOSEL 4.9 03/10] mmc: mediatek: fix race condition between msdc_request_timeout and irq

[Sasha Levin]

From: Chaotian Jing <chaotian.jing@mediatek.com>

[ Upstream commit 0354ca6edd464a2cf332f390581977b8699ed081 ]

when get request SW timeout, if CMD/DAT xfer done irq coming right now,
then there is race between the msdc_request_timeout work and irq handler,
and the host->cmd and host->data may set to NULL in irq handler. also,
current flow ensure that only one path can go to msdc_request_done(), so
no need check the return value of cancel_delayed_work().

Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com>
Link: https://lore.kernel.org/r/20201218071611.12276-1-chaotian.jing@mediatek.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/mmc/host/mtk-sd.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 7fc6ce381142..125c06a10455 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -741,13 +741,13 @@ static void msdc_track_cmd_data(struct msdc_host *host,
 static void msdc_request_done(struct msdc_host *host, struct mmc_request *mrq)
 {
 	unsigned long flags;
-	bool ret;
 
-	ret = cancel_delayed_work(&host->req_timeout);
-	if (!ret) {
-		/* delay work already running */
-		return;
-	}
+	/*
+	 * No need check the return value of cancel_delayed_work, as only ONE
+	 * path will go here!
+	 */
+	cancel_delayed_work(&host->req_timeout);
+
 	spin_lock_irqsave(&host->lock, flags);
 	host->mrq = NULL;
 	spin_unlock_irqrestore(&host->lock, flags);
@@ -765,7 +765,7 @@ static bool msdc_cmd_done(struct msdc_host *host, int events,
 	bool done = false;
 	bool sbc_error;
 	unsigned long flags;
-	u32 *rsp = cmd->resp;
+	u32 *rsp;
 
 	if (mrq->sbc && cmd == mrq->cmd &&
 	    (events & (MSDC_INT_ACMDRDY | MSDC_INT_ACMDCRCERR
@@ -786,6 +786,7 @@ static bool msdc_cmd_done(struct msdc_host *host, int events,
 
 	if (done)
 		return true;
+	rsp = cmd->resp;
 
 	sdr_clr_bits(host->base + MSDC_INTEN, cmd_ints_mask);
 
@@ -968,7 +969,7 @@ static void msdc_data_xfer_next(struct msdc_host *host,
 static bool msdc_data_xfer_done(struct msdc_host *host, u32 events,
 				struct mmc_request *mrq, struct mmc_data *data)
 {
-	struct mmc_command *stop = data->stop;
+	struct mmc_command *stop;
 	unsigned long flags;
 	bool done;
 	unsigned int check_data = events &
@@ -984,6 +985,7 @@ static bool msdc_data_xfer_done(struct msdc_host *host, u32 events,
 
 	if (done)
 		return true;
+	stop = data->stop;
 
 	if (check_data || (stop && stop->error)) {
 		dev_dbg(host->dev, "DMA status: 0x%8X\n",
-- 
2.30.1


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[PATCH AUTOSEL 4.9 07/10] PCI: xgene-msi: Fix race in installing chained irq handler

[Sasha Levin]

From: Martin Kaiser <martin@kaiser.cx>

[ Upstream commit a93c00e5f975f23592895b7e83f35de2d36b7633 ]

Fix a race where a pending interrupt could be received and the handler
called before the handler's data has been setup, by converting to
irq_set_chained_handler_and_data().

See also 2cf5a03cb29d ("PCI/keystone: Fix race in installing chained IRQ
handler").

Based on the mail discussion, it seems ok to drop the error handling.

Link: https://lore.kernel.org/r/20210115212435.19940-3-martin@kaiser.cx
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pci/host/pci-xgene-msi.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/host/pci-xgene-msi.c b/drivers/pci/host/pci-xgene-msi.c
index a6456b578269..b6a099371ad2 100644
--- a/drivers/pci/host/pci-xgene-msi.c
+++ b/drivers/pci/host/pci-xgene-msi.c
@@ -393,13 +393,9 @@ static int xgene_msi_hwirq_alloc(unsigned int cpu)
 		if (!msi_group->gic_irq)
 			continue;
 
-		irq_set_chained_handler(msi_group->gic_irq,
-					xgene_msi_isr);
-		err = irq_set_handler_data(msi_group->gic_irq, msi_group);
-		if (err) {
-			pr_err("failed to register GIC IRQ handler\n");
-			return -EINVAL;
-		}
+		irq_set_chained_handler_and_data(msi_group->gic_irq,
+			xgene_msi_isr, msi_group);
+
 		/*
 		 * Statically allocate MSI GIC IRQs to each CPU core.
 		 * With 8-core X-Gene v1, 2 MSI GIC IRQs are allocated
-- 
2.30.1


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