[media] af9015: do not use buffers from stack for usb_bulk_msg()

WARNING: at lib/dma-debug.c:947 check_for_stack+0xa7/0xf0()
ehci-pci 0000:00:04.1: DMA-API: device driver maps memory fromstack

Reported-by: poma <pomidorabelisima@gmail.com>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/usb/dvb-usb-v2/af9015.c b/drivers/media/usb/dvb-usb-v2/af9015.c
index b86d0f27a3987bbcd51335434f86658435501393..2fa7c6ee5a7019ec9498f5a0efbdbd44469a08ec 100644 (file)
--- a/drivers/media/usb/dvb-usb-v2/af9015.c
+++ b/drivers/media/usb/dvb-usb-v2/af9015.c
@@ -30,22 +30,22 @@ DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);
 
 static int af9015_ctrl_msg(struct dvb_usb_device *d, struct req_t *req)
 {
-#define BUF_LEN 63
 #define REQ_HDR_LEN 8 /* send header size */
 #define ACK_HDR_LEN 2 /* rece header size */
        struct af9015_state *state = d_to_priv(d);
        int ret, wlen, rlen;
-       u8 buf[BUF_LEN];
        u8 write = 1;
 
-       buf[0] = req->cmd;
-       buf[1] = state->seq++;
-       buf[2] = req->i2c_addr;
-       buf[3] = req->addr >> 8;
-       buf[4] = req->addr & 0xff;
-       buf[5] = req->mbox;
-       buf[6] = req->addr_len;
-       buf[7] = req->data_len;
+       mutex_lock(&d->usb_mutex);
+
+       state->buf[0] = req->cmd;
+       state->buf[1] = state->seq++;
+       state->buf[2] = req->i2c_addr;
+       state->buf[3] = req->addr >> 8;
+       state->buf[4] = req->addr & 0xff;
+       state->buf[5] = req->mbox;
+       state->buf[6] = req->addr_len;
+       state->buf[7] = req->data_len;
 
        switch (req->cmd) {
        case GET_CONFIG:
@@ -55,14 +55,14 @@ static int af9015_ctrl_msg(struct dvb_usb_device *d, struct req_t *req)
                break;
        case READ_I2C:
                write = 0;
-               buf[2] |= 0x01; /* set I2C direction */
+               state->buf[2] |= 0x01; /* set I2C direction */
        case WRITE_I2C:
-               buf[0] = READ_WRITE_I2C;
+               state->buf[0] = READ_WRITE_I2C;
                break;
        case WRITE_MEMORY:
                if (((req->addr & 0xff00) == 0xff00) ||
                    ((req->addr & 0xff00) == 0xae00))
-                       buf[0] = WRITE_VIRTUAL_MEMORY;
+                       state->buf[0] = WRITE_VIRTUAL_MEMORY;
        case WRITE_VIRTUAL_MEMORY:
        case COPY_FIRMWARE:
        case DOWNLOAD_FIRMWARE:
@@ -90,7 +90,7 @@ static int af9015_ctrl_msg(struct dvb_usb_device *d, struct req_t *req)
        rlen = ACK_HDR_LEN;
        if (write) {
                wlen += req->data_len;
-               memcpy(&buf[REQ_HDR_LEN], req->data, req->data_len);
+               memcpy(&state->buf[REQ_HDR_LEN], req->data, req->data_len);
        } else {
                rlen += req->data_len;
        }
@@ -99,22 +99,25 @@ static int af9015_ctrl_msg(struct dvb_usb_device *d, struct req_t *req)
        if (req->cmd == DOWNLOAD_FIRMWARE || req->cmd == RECONNECT_USB)
                rlen = 0;
 
-       ret = dvb_usbv2_generic_rw(d, buf, wlen, buf, rlen);
+       ret = dvb_usbv2_generic_rw_locked(d,
+                       state->buf, wlen, state->buf, rlen);
        if (ret)
                goto error;
 
        /* check status */
-       if (rlen && buf[1]) {
+       if (rlen && state->buf[1]) {
                dev_err(&d->udev->dev, "%s: command failed=%d\n",
-                               KBUILD_MODNAME, buf[1]);
+                               KBUILD_MODNAME, state->buf[1]);
                ret = -EIO;
                goto error;
        }
 
        /* read request, copy returned data to return buf */
        if (!write)
-               memcpy(req->data, &buf[ACK_HDR_LEN], req->data_len);
+               memcpy(req->data, &state->buf[ACK_HDR_LEN], req->data_len);
 error:
+       mutex_unlock(&d->usb_mutex);
+
        return ret;
 }
 

diff --git a/drivers/media/usb/dvb-usb-v2/af9015.h b/drivers/media/usb/dvb-usb-v2/af9015.h
index 533637dedd23e6ea5e97badd2f7962ab90e18b80..3a6f3ad1eadb4c961fbbb79296b2cdc98ea5cdb8 100644 (file)
--- a/drivers/media/usb/dvb-usb-v2/af9015.h
+++ b/drivers/media/usb/dvb-usb-v2/af9015.h
@@ -115,7 +115,9 @@ enum af9015_ir_mode {
        AF9015_IR_MODE_POLLING, /* just guess */
 };
 
+#define BUF_LEN 63
 struct af9015_state {
+       u8 buf[BUF_LEN]; /* bulk USB control message */
        u8 ir_mode;
        u8 rc_repeat;
        u32 rc_keycode;