kernel.git/net/can/bcm.c, branch linux-4.6.y

can: avoid using timeval for uapi

2015-10-13T15:42:34Z

The can subsystem communicates with user space using a bcm_msg_head header, which contains two timestamps. This is problematic for multiple reasons: a) The structure layout is currently incompatible between 64-bit user space and 32-bit user space, and cannot work in compat mode (other than x32). b) The timeval structure layout will change in 32-bit user space when we fix the y2038 overflow problem by redefining time_t to 64-bit, making new 32-bit user space incompatible with the current kernel interface. Cars last a long time and often use old kernels, so the actual users of this code are the most likely ones to migrate to y2038 safe user space. This tries to work around part of the problem by changing the publicly visible user interface in the header, but not the binary interface. Fortunately, the values passed around in the structure are relative times and do not actually suffer from the y2038 overflow, so 32-bit is enough here. We replace the use of 'struct timeval' with a newly defined 'struct bcm_timeval' that uses the exact same binary layout as before and that still suffers from problem a) but not problem b). The downside of this approach is that any user space program that currently assigns a timeval structure to these members rather than writing the tv_sec/tv_usec portions individually will suffer a compile-time error when built with an updated kernel header. Fixing this error makes it work fine with old and new headers though. We could address problem a) by using '__u32' or 'int' members rather than 'long', but that would have a more significant downside in also breaking support for all existing 64-bit user binaries that might be using this interface, which is likely not acceptable. Signed-off-by: Arnd Bergmann Acked-by: Oliver Hartkopp Cc: linux-can@vger.kernel.org Cc: linux-api@vger.kernel.org Signed-off-by: Marc Kleine-Budde

can: replace timestamp as unique skb attribute

2015-07-12T19:13:22Z

Commit 514ac99c64b "can: fix multiple delivery of a single CAN frame for overlapping CAN filters" requires the skb->tstamp to be set to check for identical CAN skbs. Without timestamping to be required by user space applications this timestamp was not generated which lead to commit 36c01245eb8 "can: fix loss of CAN frames in raw_rcv" - which forces the timestamp to be set in all CAN related skbuffs by introducing several __net_timestamp() calls. This forces e.g. out of tree drivers which are not using alloc_can{,fd}_skb() to add __net_timestamp() after skbuff creation to prevent the frame loss fixed in mainline Linux. This patch removes the timestamp dependency and uses an atomic counter to create an unique identifier together with the skbuff pointer. Btw: the new skbcnt element introduced in struct can_skb_priv has to be initialized with zero in out-of-tree drivers which are not using alloc_can{,fd}_skb() too. Signed-off-by: Oliver Hartkopp Cc: linux-stable Signed-off-by: Marc Kleine-Budde

net: Remove iocb argument from sendmsg and recvmsg

2015-03-02T18:06:31Z

After TIPC doesn't depend on iocb argument in its internal implementations of sendmsg() and recvmsg() hooks defined in proto structure, no any user is using iocb argument in them at all now. Then we can drop the redundant iocb argument completely from kinds of implementations of both sendmsg() and recvmsg() in the entire networking stack. Cc: Christoph Hellwig Suggested-by: Al Viro Signed-off-by: Ying Xue Signed-off-by: David S. Miller

net: use common macro for assering skb->cb[] available size in protocol families

2015-03-02T05:19:30Z

As part of an effort to move skb->dropcount to skb->cb[] use a common macro in protocol families using skb->cb[] for ancillary data to validate available room in skb->cb[]. Signed-off-by: Eyal Birger Signed-off-by: David S. Miller

can: fix spelling errors

2014-12-07T20:22:05Z

Fix various spelling errors in the comments of the CAN modules. Signed-off-by: Jeremiah Mahler Acked-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde

can: eliminate banner[] variable and switch to pr_info()

2014-12-07T20:22:01Z

Several CAN modules use a design pattern with a banner[] variable at the top which defines a string that is used once during init to print the banner. The string is also embedded with KERN_INFO which makes it printk() specific. Improve the code by eliminating the banner[] variable and moving the string to where it is printed. Then switch from printk(KERN_INFO to pr_info() for the lines that were changed. Signed-off-by: Jeremiah Mahler Acked-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde

new helper: memcpy_to_msg()

2014-11-24T09:28:51Z

Signed-off-by: Al Viro

new helper: memcpy_from_msg()

2014-11-24T09:28:48Z

Signed-off-by: Al Viro

can: add destructor for self generated skbs

2014-01-31T00:25:49Z

Self generated skbuffs in net/can/bcm.c are setting a skb->sk reference but no explicit destructor which is enforced since Linux 3.11 with commit 376c7311bdb6 (net: add a temporary sanity check in skb_orphan()). This patch adds some helper functions to make sure that a destructor is properly defined when a sock reference is assigned to a CAN related skb. To create an unshared skb owned by the original sock a common helper function has been introduced to replace open coded functions to create CAN echo skbs. Signed-off-by: Oliver Hartkopp Tested-by: Andre Naujoks Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller

net: add build-time checks for msg->msg_name size

2014-01-19T07:04:16Z

This is a follow-up patch to f3d3342602f8bc ("net: rework recvmsg handler msg_name and msg_namelen logic"). DECLARE_SOCKADDR validates that the structure we use for writing the name information to is not larger than the buffer which is reserved for msg->msg_name (which is 128 bytes). Also use DECLARE_SOCKADDR consistently in sendmsg code paths. Signed-off-by: Steffen Hurrle Suggested-by: Hannes Frederic Sowa Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller