[PATCHv2] USB CDC NCM: tx_fixup() race condition fix
From: Alexey Orishko <hidden>
Date: 2011-01-17 17:08:12
Subsystem:
networking drivers, the rest, usb cdc ethernet driver, usb networking drivers · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Oliver Neukum
- tx_fixup() can be called from either timer callback or from xmit() in usbnet, so spinlock is added to avoid concurrency-related problem. - minor correction due to checkpatch warning for some line over 80 chars after previous patch was applied. Signed-off-by: Alexey Orishko <redacted> --- drivers/net/usb/cdc_ncm.c | 19 ++++++++++++------- 1 files changed, 12 insertions(+), 7 deletions(-)
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index d776c4a..04e8ce1 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c@@ -54,7 +54,7 @@ #include <linux/usb/usbnet.h> #include <linux/usb/cdc.h> -#define DRIVER_VERSION "30-Nov-2010" +#define DRIVER_VERSION "17-Jan-2011" /* CDC NCM subclass 3.2.1 */ #define USB_CDC_NCM_NDP16_LENGTH_MIN 0x10
@@ -868,15 +868,19 @@ static void cdc_ncm_tx_timeout(unsigned long arg) if (ctx->tx_timer_pending != 0) { ctx->tx_timer_pending--; restart = 1; - } else + } else { restart = 0; + } spin_unlock(&ctx->mtx); - if (restart) + if (restart) { + spin_lock(&ctx->mtx); cdc_ncm_tx_timeout_start(ctx); - else if (ctx->netdev != NULL) + spin_unlock(&ctx->mtx); + } else if (ctx->netdev != NULL) { usbnet_start_xmit(NULL, ctx->netdev); + } } static struct sk_buff *
@@ -900,7 +904,6 @@ cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags) skb_out = cdc_ncm_fill_tx_frame(ctx, skb); if (ctx->tx_curr_skb != NULL) need_timer = 1; - spin_unlock(&ctx->mtx); /* Start timer, if there is a remaining skb */ if (need_timer)
@@ -908,6 +911,8 @@ cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags) if (skb_out) dev->net->stats.tx_packets += ctx->tx_curr_frame_num; + + spin_unlock(&ctx->mtx); return skb_out; error:
@@ -1020,8 +1025,8 @@ static int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in) if (((offset + temp) > actlen) || (temp > CDC_NCM_MAX_DATAGRAM_SIZE) || (temp < ETH_HLEN)) { pr_debug("invalid frame detected (ignored)" - "offset[%u]=%u, length=%u, skb=%p\n", - x, offset, temp, skb_in); + "offset[%u]=%u, length=%u, skb=%p\n", + x, offset, temp, skb_in); if (!x) goto error; break;
--
1.7.0.4