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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>
This commit is contained in:
Alexey Khoroshilov 2013-01-11 13:01:39 +04:00 committed by Greg Kroah-Hartman
parent ccbdccd4a7
commit 955e7da82d
3 changed files with 14 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
drivers/staging/ced1401/ced_ioc.c
View File

@ -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

10
drivers/staging/ced1401/usb1401.c
View File

@ -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

2
drivers/staging/ced1401/usb1401.h
View File

@ -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,