diff options
Diffstat (limited to 'ums-realtek-driver-uses-stack-memory-for-DMA.patch')
| -rw-r--r-- | ums-realtek-driver-uses-stack-memory-for-DMA.patch | 143 |
1 files changed, 0 insertions, 143 deletions
diff --git a/ums-realtek-driver-uses-stack-memory-for-DMA.patch b/ums-realtek-driver-uses-stack-memory-for-DMA.patch deleted file mode 100644 index 98c8b0cf9..000000000 --- a/ums-realtek-driver-uses-stack-memory-for-DMA.patch +++ /dev/null @@ -1,143 +0,0 @@ -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(-) - --- -To unsubscribe from this list: send the line "unsubscribe linux-kernel" in -the body of a message to majordomo@vger.kernel.org -More majordomo info at http://vger.kernel.org/majordomo-info.html -Please read the FAQ at http://www.tux.org/lkml/ - -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; - } - |