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-rw-r--r--Documentation/kernel-parameters.txt4
-rw-r--r--drivers/usb/core/devio.c9
2 files changed, 12 insertions, 1 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 742f69d18fc8..e6b6e056cc11 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -3874,6 +3874,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
usbcore.usbfs_snoop=
[USB] Set to log all usbfs traffic (default 0 = off).
+ usbcore.usbfs_snoop_max=
+ [USB] Maximum number of bytes to snoop in each URB
+ (default = 65536).
+
usbcore.blinkenlights=
[USB] Set to cycle leds on hubs (default 0 = off).
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 38ae877c46e3..3d41faf6e607 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -100,6 +100,11 @@ static bool usbfs_snoop;
module_param(usbfs_snoop, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(usbfs_snoop, "true to log all usbfs traffic");
+static unsigned usbfs_snoop_max = 65536;
+module_param(usbfs_snoop_max, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(usbfs_snoop_max,
+ "maximum number of bytes to print while snooping");
+
#define snoop(dev, format, arg...) \
do { \
if (usbfs_snoop) \
@@ -392,6 +397,7 @@ static void snoop_urb(struct usb_device *udev,
ep, t, d, length, timeout_or_status);
}
+ data_len = min(data_len, usbfs_snoop_max);
if (data && data_len > 0) {
print_hex_dump(KERN_DEBUG, "data: ", DUMP_PREFIX_NONE, 32, 1,
data, data_len, 1);
@@ -402,7 +408,8 @@ static void snoop_urb_data(struct urb *urb, unsigned len)
{
int i, size;
- if (!usbfs_snoop)
+ len = min(len, usbfs_snoop_max);
+ if (!usbfs_snoop || len == 0)
return;
if (urb->num_sgs == 0) {