staging: ced1401: fix GFP_KERNEL in spinlock context

Allowi() calls usb_submit_urb(pdx->pUrbCharIn, bInCallback ? GFP_ATOMIC : GFP_KERNEL)
under spin_lock_irqsave(&pdx->charInLock, flags). That means it should use GFP_ATOMIC anyway.
As soon as it is the only usage of bInCallback argument, the patch removes it at all.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/ced1401/ced_ioc.c b/drivers/staging/ced1401/ced_ioc.c
index d0434714afd3ee04cb53abccc0594a2a2c99bd57..82a333f6433e3f4a852e4ed62f7936bfe4ad707b 100644 (file)
--- a/drivers/staging/ced1401/ced_ioc.c
+++ b/drivers/staging/ced1401/ced_ioc.c
@@ -123,7 +123,7 @@ int SendString(DEVICE_EXTENSION * pdx, const char __user * pData,
                iReturn = PutChars(pdx, buffer, n);
        }
 
-       Allowi(pdx, false);     // make sure we have input int
+       Allowi(pdx);            // make sure we have input int
        mutex_unlock(&pdx->io_mutex);
 
        return iReturn;
@@ -140,7 +140,7 @@ int SendChar(DEVICE_EXTENSION * pdx, char c)
        mutex_lock(&pdx->io_mutex);     // Protect disconnect from new i/o
        iReturn = PutChars(pdx, &c, 1);
        dev_dbg(&pdx->interface->dev, "SendChar >%c< (0x%02x)", c, c);
-       Allowi(pdx, false);     // Make sure char reads are running
+       Allowi(pdx);    // Make sure char reads are running
        mutex_unlock(&pdx->io_mutex);
        return iReturn;
 }
@@ -433,8 +433,8 @@ int GetChar(DEVICE_EXTENSION * pdx)
 
        dev_dbg(&pdx->interface->dev, "GetChar");
 
-       Allowi(pdx, false);     // Make sure char reads are running
-       SendChars(pdx);         // and send any buffered chars
+       Allowi(pdx);    // Make sure char reads are running
+       SendChars(pdx); // and send any buffered chars
 
        spin_lock_irq(&pdx->charInLock);
        if (pdx->dwNumInput > 0)        // worth looking
@@ -447,7 +447,7 @@ int GetChar(DEVICE_EXTENSION * pdx)
                iReturn = U14ERR_NOIN;  // no input data to read
        spin_unlock_irq(&pdx->charInLock);
 
-       Allowi(pdx, false);     // Make sure char reads are running
+       Allowi(pdx);    // Make sure char reads are running
 
        mutex_unlock(&pdx->io_mutex);   // Protect disconnect from new i/o
        return iReturn;
@@ -472,7 +472,7 @@ int GetString(DEVICE_EXTENSION * pdx, char __user * pUser, int n)
                return -ENOMEM;
 
        mutex_lock(&pdx->io_mutex);     // Protect disconnect from new i/o
-       Allowi(pdx, false);     // Make sure char reads are running
+       Allowi(pdx);    // Make sure char reads are running
        SendChars(pdx);         // and send any buffered chars
 
        spin_lock_irq(&pdx->charInLock);
@@ -518,7 +518,7 @@ int GetString(DEVICE_EXTENSION * pdx, char __user * pUser, int n)
        } else
                spin_unlock_irq(&pdx->charInLock);
 
-       Allowi(pdx, false);     // Make sure char reads are running
+       Allowi(pdx);    // Make sure char reads are running
        mutex_unlock(&pdx->io_mutex);   // Protect disconnect from new i/o
 
        return iReturn;
@@ -531,7 +531,7 @@ int Stat1401(DEVICE_EXTENSION * pdx)
 {
        int iReturn;
        mutex_lock(&pdx->io_mutex);     // Protect disconnect from new i/o
-       Allowi(pdx, false);     // make sure we allow pending chars
+       Allowi(pdx);            // make sure we allow pending chars
        SendChars(pdx);         // in both directions
        iReturn = pdx->dwNumInput;      // no lock as single read
        mutex_unlock(&pdx->io_mutex);   // Protect disconnect from new i/o
@@ -550,7 +550,7 @@ int LineCount(DEVICE_EXTENSION * pdx)
        int iReturn = 0;        // will be count of line ends
 
        mutex_lock(&pdx->io_mutex);     // Protect disconnect from new i/o
-       Allowi(pdx, false);     // Make sure char reads are running
+       Allowi(pdx);            // Make sure char reads are running
        SendChars(pdx);         // and send any buffered chars
        spin_lock_irq(&pdx->charInLock);        // Get protection
 

diff --git a/drivers/staging/ced1401/usb1401.c b/drivers/staging/ced1401/usb1401.c
index a27043a2f8c51011677f76c6f52e581b268603ef..60bed3e90fb835e7e69fc2897b6131e6b417bbce 100644 (file)
--- a/drivers/staging/ced1401/usb1401.c
+++ b/drivers/staging/ced1401/usb1401.c
@@ -697,7 +697,7 @@ static void staged_callback(struct urb *pUrb)
        // in Allowi as if it were protected by the char lock. In any case, most systems will
        // not be upset by char input during DMA... sigh. Needs sorting out.
        if (bRestartCharInput)  // may be out of date, but...
-               Allowi(pdx, true);      // ...Allowi tests a lock too.
+               Allowi(pdx);    // ...Allowi tests a lock too.
        dev_dbg(&pdx->interface->dev, "%s done", __func__);
 }
 
@@ -1172,7 +1172,7 @@ static void ced_readchar_callback(struct urb *pUrb)
        pdx->bReadCharsPending = false; // No longer have a pending read
        spin_unlock(&pdx->charInLock);  // already at irq level
 
-       Allowi(pdx, true);      // see if we can do the next one
+       Allowi(pdx);    // see if we can do the next one
 }
 
 /****************************************************************************
@@ -1182,7 +1182,7 @@ static void ced_readchar_callback(struct urb *pUrb)
 ** we can pick up any inward transfers. This can be called in multiple contexts
 ** so we use the irqsave version of the spinlock.
 ****************************************************************************/
-int Allowi(DEVICE_EXTENSION * pdx, bool bInCallback)
+int Allowi(DEVICE_EXTENSION * pdx)
 {
        int iReturn = U14ERR_NOERROR;
        unsigned long flags;
@@ -1211,9 +1211,7 @@ int Allowi(DEVICE_EXTENSION * pdx, bool bInCallback)
                                 pdx, pdx->bInterval);
                pdx->pUrbCharIn->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;     // short xfers are OK by default
                usb_anchor_urb(pdx->pUrbCharIn, &pdx->submitted);       // in case we need to kill it
-               iReturn =
-                   usb_submit_urb(pdx->pUrbCharIn,
-                                  bInCallback ? GFP_ATOMIC : GFP_KERNEL);
+               iReturn = usb_submit_urb(pdx->pUrbCharIn, GFP_ATOMIC);
                if (iReturn) {
                        usb_unanchor_urb(pdx->pUrbCharIn);      // remove from list of active Urbs
                        pdx->bPipeError[nPipe] = 1;     // Flag an error to be handled later

diff --git a/drivers/staging/ced1401/usb1401.h b/drivers/staging/ced1401/usb1401.h
index adb5fa402bd4ebd290e2012afecf873720414b48..8fc6958b6f08d32438f6bf751eec93a8daeb1558 100644 (file)
--- a/drivers/staging/ced1401/usb1401.h
+++ b/drivers/staging/ced1401/usb1401.h
@@ -204,7 +204,7 @@ typedef struct _DEVICE_EXTENSION
 
 /// Definitions of routimes used between compilation object files
 // in usb1401.c
-extern int Allowi(DEVICE_EXTENSION* pdx, bool bInCallback);
+extern int Allowi(DEVICE_EXTENSION* pdx);
 extern int SendChars(DEVICE_EXTENSION* pdx);
 extern void ced_draw_down(DEVICE_EXTENSION *pdx);
 extern int ReadWriteMem(DEVICE_EXTENSION *pdx, bool Read, unsigned short wIdent,