From 1b464848496676c9408fe625d6bb32e777336052 Mon Sep 17 00:00:00 2001
From: chao an <anchao@xiaomi.com>
Date: Tue, 21 Mar 2023 21:55:58 +0800
Subject: [PATCH] mmcsd/sdio: fix potential race condition in sdio

sdio driver should ensure the thread safety

Signed-off-by: chao an <anchao@xiaomi.com>
---
 drivers/mmcsd/sdio.c | 72 +++++++++++++++++++++++++++++++++++---------
 include/nuttx/sdio.h |  3 ++
 2 files changed, 60 insertions(+), 15 deletions(-)

diff --git a/drivers/mmcsd/sdio.c b/drivers/mmcsd/sdio.c
index 06a50d4f9e..38dd15ea8a 100644
--- a/drivers/mmcsd/sdio.c
+++ b/drivers/mmcsd/sdio.c
@@ -39,14 +39,6 @@
 #define SDIO_CMD53_TIMEOUT_MS 100
 #define SDIO_IDLE_DELAY_MS    50
 
-#ifdef CONFIG_SDIO_MUXBUS
-#  define SDIO_TAKELOCK(dev)  SDIO_LOCK(dev, true)
-#  define SDIO_GIVELOCK(dev)  SDIO_LOCK(dev, false)
-#else
-#  define SDIO_TAKELOCK(dev)
-#  define SDIO_GIVELOCK(dev)
-#endif
-
 /****************************************************************************
  * Private Types
  ****************************************************************************/
@@ -101,6 +93,54 @@ union sdio_cmd5x
  * Private Functions
  ****************************************************************************/
 
+static int sdio_takelock(FAR struct sdio_dev_s *dev)
+{
+  int ret;
+
+  /* Take the lock, giving exclusive access to the driver (perhaps
+   * waiting)
+   */
+
+  if (!up_interrupt_context() && !sched_idletask())
+    {
+      ret = nxmutex_lock(&dev->mutex);
+      if (ret < 0)
+        {
+          return ret;
+        }
+
+      /* Lock the bus if mutually exclusive access to the
+       * SDIO bus is required on this platform.
+       */
+
+#ifdef CONFIG_SDIO_MUXBUS
+      SDIO_LOCK(dev, true);
+#endif
+    }
+  else
+    {
+      ret = OK;
+    }
+
+  return ret;
+}
+
+static void sdio_givelock(FAR struct sdio_dev_s *dev)
+{
+  if (!up_interrupt_context() && !sched_idletask())
+    {
+      /* Release the SDIO bus lock, then the MMC/SD driver mutex in the
+       * opposite order that they were taken to assure that no deadlock
+       * conditions will arise.
+       */
+
+#ifdef CONFIG_SDIO_MUXBUS
+      SDIO_LOCK(dev, false);
+#endif
+      nxmutex_unlock(&dev->mutex);
+    }
+}
+
 static int sdio_sendcmdpoll(FAR struct sdio_dev_s *dev,
                             uint32_t cmd, uint32_t arg)
 {
@@ -158,10 +198,10 @@ int sdio_io_rw_direct(FAR struct sdio_dev_s *dev, bool write,
 
   /* Send CMD52 command */
 
-  SDIO_TAKELOCK(dev);
+  sdio_takelock(dev);
   sdio_sendcmdpoll(dev, SD_ACMD52, arg.value);
   ret = SDIO_RECVR5(dev, SD_ACMD52, &data);
-  SDIO_GIVELOCK(dev);
+  sdio_givelock(dev);
 
   if (ret != OK)
     {
@@ -228,7 +268,7 @@ int sdio_io_rw_extended(FAR struct sdio_dev_s *dev, bool write,
       arg.cmd53.byte_block_count = nblocks;
     }
 
-  SDIO_TAKELOCK(dev);
+  sdio_takelock(dev);
 
   /* Send CMD53 command */
 
@@ -276,7 +316,7 @@ int sdio_io_rw_extended(FAR struct sdio_dev_s *dev, bool write,
   /* There may not be a response to this, so don't look for one */
 
   SDIO_RECVR1(dev, SD_ACMD52ABRT, &data);
-  SDIO_GIVELOCK(dev);
+  sdio_givelock(dev);
 
   if (ret != OK)
     {
@@ -342,7 +382,9 @@ int sdio_probe(FAR struct sdio_dev_s *dev)
   int ret;
   uint32_t data = 0;
 
-  SDIO_TAKELOCK(dev);
+  nxmutex_init(&dev->mutex);
+
+  sdio_takelock(dev);
 
   /* Set device state from reset to idle */
 
@@ -407,11 +449,11 @@ int sdio_probe(FAR struct sdio_dev_s *dev)
 
   /* Configure 4 bits bus width */
 
-  SDIO_GIVELOCK(dev);
+  sdio_givelock(dev);
   return sdio_set_wide_bus(dev);
 
 err:
-  SDIO_GIVELOCK(dev);
+  sdio_givelock(dev);
   return ret;
 }
 
diff --git a/include/nuttx/sdio.h b/include/nuttx/sdio.h
index b2a928e4be..0862e5a448 100644
--- a/include/nuttx/sdio.h
+++ b/include/nuttx/sdio.h
@@ -32,6 +32,7 @@
 #include <stdbool.h>
 
 #include <nuttx/wqueue.h>
+#include <nuttx/mutex.h>
 
 /****************************************************************************
  * Pre-processor Definitions
@@ -963,6 +964,8 @@ struct sdio_dev_s
 
   /* Mutual exclusion */
 
+  mutex_t mutex; /* Assures mutually exclusive access to the slot */
+
 #ifdef CONFIG_SDIO_MUXBUS
   int   (*lock)(FAR struct sdio_dev_s *dev, bool lock);
 #endif