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| author | Adam Cozzette <acozzette@cs.hmc.edu> | 2011-08-24 12:22:37 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-11-11 09:42:49 -0800 |
| commit | 5de4a6505f61c1edd821e48795581a19f8f2d6dc (patch) | |
| tree | 6d433fd6ec69f64926985ed00fed237728cd0974 /drivers | |
| parent | 3401c775a446527091f720a6c65a1ecc7644776a (diff) | |
| download | lwn-5de4a6505f61c1edd821e48795581a19f8f2d6dc.tar.gz lwn-5de4a6505f61c1edd821e48795581a19f8f2d6dc.zip | |
ums_realtek: do not use stack memory for DMA
commit 065e60964e293227e4feb0c1f7e27e609316ed9a upstream.
This patch changes 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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/storage/realtek_cr.c | 35 |
1 files changed, 30 insertions, 5 deletions
diff --git a/drivers/usb/storage/realtek_cr.c b/drivers/usb/storage/realtek_cr.c index 34adc4b42ceb..232167ad4781 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; } |