3.0-git17 snapshot

Add changes for rhbz 720128,720054,708314

1 files changed, 143 insertions, 0 deletions

diff --git a/ums-realtek-driver-uses-stack-memory-for-DMA.patch b/ums-realtek-driver-uses-stack-memory-for-DMA.patch
new file mode 100644
index 000000000..98c8b0cf9
--- /dev/null
+++ b/ums-realtek-driver-uses-stack-memory-for-DMA.patch
@@ -0,0 +1,143 @@
+From patchwork Tue Aug  2 05:04:11 2011
+Content-Type: text/plain; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 8bit
+Subject: ums-realtek driver uses stack memory for DMA
+Date: Tue, 02 Aug 2011 05:04:11 -0000
+From: Adam Cozzette <acozzette@cs.hmc.edu>
+X-Patchwork-Id: 1028062
+Message-Id: <20110802050411.GC3857@[192.168.0.12]>
+To: Josh Boyer <jwboyer@redhat.com>
+Cc: edwin_rong <edwin_rong@realsil.com.cn>, wwang <wei_wang@realsil.com.cn>, 
+ Greg Kroah-Hartman <gregkh@suse.de>, linux-usb@vger.kernel.org,
+ linux-kernel@vger.kernel.org
+
+On Mon, Aug 01, 2011 at 05:09:06PM -0400, Josh Boyer wrote:
+> Hello,
+> 
+> We have a report that the ums-realtek driver is generating a backtrace
+> due to using stack variables for DMA buffers.  The backtrace is below
+> and you can view the bug report here:
+> https://bugzilla.redhat.com/show_bug.cgi?id=720054
+> 
+> Looking through the code, it seems that every call to rts51x_read_mem,
+> rts51x_write_mem, and rts51x_read_status passes a stack variable to
+> rts51x_bulk_transport, which then calls usb_stor_bulk_transfer_buf with
+> this and generates the backtrace.  It is my understanding that the
+> driver should be passing variables that are not on the stack and have
+> been allocated with memory that will be suitable for the DMA api (e.g.
+> kmalloc).
+> 
+> Was this missed during the initial review and is anyone working on
+> adapting the driver to be compliant?
+
+Could you try out this patch if it looks ok to you? I have not tested it because
+unfortunately I don't have the hardware. Right now it generates some compile
+warnings like this one:
+
+drivers/usb/storage/realtek_cr.c:419:40: warning: ‘buf[0]’ may be used uninitialized in this function [-Wuninitialized]
+
+It think they are harmless but I didn't see an obvious way to get rid of them,
+so if you have any suggestions I would be glad to hear them.
+
+This patch changed rts51x_read_mem, rts51x_write_mem, and rts51x_read_status to
+allocate temporary buffers with kmalloc. This way stack addresses are not used
+for DMA when these functions call rts51x_bulk_transport.
+
+Signed-off-by: Adam Cozzette <acozzette@cs.hmc.edu>
+
+---
+realtek_cr.c |   35 ++++++++++++++++++++++++++++++-----
+ 1 file changed, 30 insertions(+), 5 deletions(-)
+
+--
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+
+diff --git a/drivers/usb/storage/realtek_cr.c b/drivers/usb/storage/realtek_cr.c
+index 34adc4b..232167a 100644
+--- a/drivers/usb/storage/realtek_cr.c
++++ b/drivers/usb/storage/realtek_cr.c
+@@ -320,6 +320,11 @@ static int rts51x_read_mem(struct us_data *us, u16 addr, u8 *data, u16 len)
+ {
+ 	int retval;
+ 	u8 cmnd[12] = { 0 };
++	u8 *buf;
++
++	buf = kmalloc(len, GFP_NOIO);
++	if (buf == NULL)
++		return USB_STOR_TRANSPORT_ERROR;
+ 
+ 	US_DEBUGP("%s, addr = 0x%x, len = %d\n", __func__, addr, len);
+ 
+@@ -331,10 +336,14 @@ static int rts51x_read_mem(struct us_data *us, u16 addr, u8 *data, u16 len)
+ 	cmnd[5] = (u8) len;
+ 
+ 	retval = rts51x_bulk_transport(us, 0, cmnd, 12,
+-				       data, len, DMA_FROM_DEVICE, NULL);
+-	if (retval != USB_STOR_TRANSPORT_GOOD)
++				       buf, len, DMA_FROM_DEVICE, NULL);
++	if (retval != USB_STOR_TRANSPORT_GOOD) {
++		kfree(buf);
+ 		return -EIO;
++	}
+ 
++	memcpy(data, buf, len);
++	kfree(buf);
+ 	return 0;
+ }
+ 
+@@ -342,6 +351,12 @@ static int rts51x_write_mem(struct us_data *us, u16 addr, u8 *data, u16 len)
+ {
+ 	int retval;
+ 	u8 cmnd[12] = { 0 };
++	u8 *buf;
++
++	buf = kmalloc(len, GFP_NOIO);
++	if (buf == NULL)
++		return USB_STOR_TRANSPORT_ERROR;
++	memcpy(buf, data, len);
+ 
+ 	US_DEBUGP("%s, addr = 0x%x, len = %d\n", __func__, addr, len);
+ 
+@@ -353,7 +368,8 @@ static int rts51x_write_mem(struct us_data *us, u16 addr, u8 *data, u16 len)
+ 	cmnd[5] = (u8) len;
+ 
+ 	retval = rts51x_bulk_transport(us, 0, cmnd, 12,
+-				       data, len, DMA_TO_DEVICE, NULL);
++				       buf, len, DMA_TO_DEVICE, NULL);
++	kfree(buf);
+ 	if (retval != USB_STOR_TRANSPORT_GOOD)
+ 		return -EIO;
+ 
+@@ -365,6 +381,11 @@ static int rts51x_read_status(struct us_data *us,
+ {
+ 	int retval;
+ 	u8 cmnd[12] = { 0 };
++	u8 *buf;
++
++	buf = kmalloc(len, GFP_NOIO);
++	if (buf == NULL)
++		return USB_STOR_TRANSPORT_ERROR;
+ 
+ 	US_DEBUGP("%s, lun = %d\n", __func__, lun);
+ 
+@@ -372,10 +393,14 @@ static int rts51x_read_status(struct us_data *us,
+ 	cmnd[1] = 0x09;
+ 
+ 	retval = rts51x_bulk_transport(us, lun, cmnd, 12,
+-				       status, len, DMA_FROM_DEVICE, actlen);
+-	if (retval != USB_STOR_TRANSPORT_GOOD)
++				       buf, len, DMA_FROM_DEVICE, actlen);
++	if (retval != USB_STOR_TRANSPORT_GOOD) {
++		kfree(buf);
+ 		return -EIO;
++	}
+ 
++	memcpy(status, buf, len);
++	kfree(buf);
+ 	return 0;
+ }
+