From 5d0f2df471f50c0ef1512d114ab5c711adfe2103 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Sat, 27 Feb 2016 07:51:10 -0300 Subject: [PATCH] [media] technisat-usb2: don't do DMA on the stack As warned by smatch: drivers/media/usb/dvb-usb/technisat-usb2.c:263 technisat_usb2_set_led() error: doing dma on the stack (led) drivers/media/usb/dvb-usb/technisat-usb2.c:280 technisat_usb2_set_led_timer() error: doing dma on the stack (&b) drivers/media/usb/dvb-usb/technisat-usb2.c:341 technisat_usb2_identify_state() error: doing dma on the stack (version) drivers/media/usb/dvb-usb/technisat-usb2.c:609 technisat_usb2_get_ir() error: doing dma on the stack (buf) drivers/media/usb/dvb-usb/technisat-usb2.c:619 technisat_usb2_get_ir() error: doing dma on the stack (buf) Create a buffer at the device state and use it for all the DMA transfers. Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/dvb-usb/technisat-usb2.c | 41 ++++++++++++++-------- 1 file changed, 27 insertions(+), 14 deletions(-) diff --git a/drivers/media/usb/dvb-usb/technisat-usb2.c b/drivers/media/usb/dvb-usb/technisat-usb2.c index 51487d2f7764..d9f3262bf071 100644 --- a/drivers/media/usb/dvb-usb/technisat-usb2.c +++ b/drivers/media/usb/dvb-usb/technisat-usb2.c @@ -60,6 +60,8 @@ struct technisat_usb2_state { u8 power_state; u16 last_scan_code; + + u8 buf[64]; }; /* debug print helpers */ @@ -220,19 +222,19 @@ enum technisat_usb2_led_state { TECH_LED_UNDEFINED }; -static int technisat_usb2_set_led(struct dvb_usb_device *d, int red, enum technisat_usb2_led_state state) +static int technisat_usb2_set_led(struct dvb_usb_device *d, int red, + enum technisat_usb2_led_state st) { + struct technisat_usb2_state *state = d->priv; + u8 *led = state->buf; int ret; - u8 led[8] = { - red ? SET_RED_LED_VENDOR_REQUEST : SET_GREEN_LED_VENDOR_REQUEST, - 0 - }; + led[0] = red ? SET_RED_LED_VENDOR_REQUEST : SET_GREEN_LED_VENDOR_REQUEST; - if (disable_led_control && state != TECH_LED_OFF) + if (disable_led_control && st != TECH_LED_OFF) return 0; - switch (state) { + switch (st) { case TECH_LED_ON: led[1] = 0x82; break; @@ -263,7 +265,7 @@ static int technisat_usb2_set_led(struct dvb_usb_device *d, int red, enum techni red ? SET_RED_LED_VENDOR_REQUEST : SET_GREEN_LED_VENDOR_REQUEST, USB_TYPE_VENDOR | USB_DIR_OUT, 0, 0, - led, sizeof(led), 500); + led, 8, 500); mutex_unlock(&d->i2c_mutex); return ret; @@ -271,8 +273,11 @@ static int technisat_usb2_set_led(struct dvb_usb_device *d, int red, enum techni static int technisat_usb2_set_led_timer(struct dvb_usb_device *d, u8 red, u8 green) { + struct technisat_usb2_state *state = d->priv; + u8 *b = state->buf; int ret; - u8 b = 0; + + b[0] = 0; if (mutex_lock_interruptible(&d->i2c_mutex) < 0) return -EAGAIN; @@ -281,7 +286,7 @@ static int technisat_usb2_set_led_timer(struct dvb_usb_device *d, u8 red, u8 gre SET_LED_TIMER_DIVIDER_VENDOR_REQUEST, USB_TYPE_VENDOR | USB_DIR_OUT, (red << 8) | green, 0, - &b, 1, 500); + b, 1, 500); mutex_unlock(&d->i2c_mutex); @@ -328,7 +333,11 @@ static int technisat_usb2_identify_state(struct usb_device *udev, struct dvb_usb_device_description **desc, int *cold) { int ret; - u8 version[3]; + u8 *version; + + version = kmalloc(3, GFP_KERNEL); + if (!version) + return -ENOMEM; /* first select the interface */ if (usb_set_interface(udev, 0, 1) != 0) @@ -342,7 +351,7 @@ static int technisat_usb2_identify_state(struct usb_device *udev, GET_VERSION_INFO_VENDOR_REQUEST, USB_TYPE_VENDOR | USB_DIR_IN, 0, 0, - version, sizeof(version), 500); + version, 3, 500); if (ret < 0) *cold = 1; @@ -351,6 +360,8 @@ static int technisat_usb2_identify_state(struct usb_device *udev, *cold = 0; } + kfree(version); + return 0; } @@ -594,7 +605,9 @@ static int technisat_usb2_frontend_attach(struct dvb_usb_adapter *a) static int technisat_usb2_get_ir(struct dvb_usb_device *d) { - u8 buf[62], *b; + struct technisat_usb2_state *state = d->priv; + u8 *buf = state->buf; + u8 *b; int ret; struct ir_raw_event ev; @@ -620,7 +633,7 @@ static int technisat_usb2_get_ir(struct dvb_usb_device *d) GET_IR_DATA_VENDOR_REQUEST, USB_TYPE_VENDOR | USB_DIR_IN, 0x8080, 0, - buf, sizeof(buf), 500); + buf, 62, 500); unlock: mutex_unlock(&d->i2c_mutex); -- 2.30.2