linux.git/net/core/drop_monitor.c, branch v5.10

genetlink: move to smaller ops wherever possible

2020-10-03T02:11:11+00:00

Bulk of the genetlink users can use smaller ops, move them.

Signed-off-by: Jakub Kicinski 
Reviewed-by: Johannes Berg 
Signed-off-by: David S. Miller

drop_monitor: Filter control packets in drop monitor

2020-10-01T01:01:26+00:00

Previously, devlink called into drop monitor in order to report hardware
originated drops / exceptions. devlink intentionally filtered control
packets and did not pass them to drop monitor as they were not dropped
by the underlying hardware.

Now drop monitor registers its probe on a generic 'devlink_trap_report'
tracepoint and should therefore perform this filtering itself instead of
having devlink do that.

Add the trap type as metadata and have drop monitor ignore control
packets.

Signed-off-by: Ido Schimmel 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller

drop_monitor: Remove duplicate struct

2020-10-01T01:01:26+00:00

'struct net_dm_hw_metadata' is a duplicate of 'struct
devlink_trap_metadata'.

Remove the former and simplify the code.

Signed-off-by: Ido Schimmel 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller

drop_monitor: Remove no longer used functions

2020-10-01T01:01:26+00:00

The old probe functions that were invoked by drop monitor code are no
longer called and can thus be removed. They were replaced by actual
probe functions that are registered on the recently introduced
'devlink_trap_report' tracepoint.

Signed-off-by: Ido Schimmel 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller

drop_monitor: Convert to using devlink tracepoint

2020-10-01T01:01:26+00:00

Convert drop monitor to use the recently introduced
'devlink_trap_report' tracepoint instead of having devlink call into
drop monitor.

This is both consistent with software originated drops ('kfree_skb'
tracepoint) and also allows drop monitor to be built as a module and
still report hardware originated drops.

Signed-off-by: Ido Schimmel 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller

drop_monitor: Prepare probe functions for devlink tracepoint

2020-10-01T01:01:26+00:00

Drop monitor supports two alerting modes: Summary and packet. Prepare a
probe function for each, so that they could be later registered on the
devlink tracepoint by calling register_trace_devlink_trap_report(),
based on the configured alerting mode.

Signed-off-by: Ido Schimmel 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva

net: Add MODULE_DESCRIPTION entries to network modules

2020-06-21T04:33:57+00:00

The user tool modinfo is used to get information on kernel modules, including a
description where it is available.

This patch adds a brief MODULE_DESCRIPTION to the following modules:

9p
drop_monitor
esp4_offload
esp6_offload
fou
fou6
ila
sch_fq
sch_fq_codel
sch_hhf

Signed-off-by: Rob Gill 
Signed-off-by: David S. Miller

drop_monitor: work around gcc-10 stringop-overflow warning

2020-05-01T22:45:16+00:00

The current gcc-10 snapshot produces a false-positive warning:

net/core/drop_monitor.c: In function 'trace_drop_common.constprop':
cc1: error: writing 8 bytes into a region of size 0 [-Werror=stringop-overflow=]
In file included from net/core/drop_monitor.c:23:
include/uapi/linux/net_dropmon.h:36:8: note: at offset 0 to object 'entries' with size 4 declared here
   36 |  __u32 entries;
      |        ^~~~~~~

I reported this in the gcc bugzilla, but in case it does not get
fixed in the release, work around it by using a temporary variable.

Fixes: 9a8afc8d3962 ("Network Drop Monitor: Adding drop monitor implementation & Netlink protocol")
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94881
Signed-off-by: Arnd Bergmann 
Acked-by: Neil Horman 
Signed-off-by: David S. Miller

net: core: Replace zero-length array with flexible-array member

2020-02-28T20:08:37+00:00

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva 
Signed-off-by: David S. Miller