linux-toradex.git/samples/bpf/bpf_helpers.h, branch v4.9.74

bpf/samples: Fix PT_REGS_IP on s390x and use it

2016-11-28T21:26:46+00:00

The files "sampleip_kern.c" and "trace_event_kern.c" directly access
"ctx->regs.ip" which is not available on s390x. Fix this and use the
PT_REGS_IP() macro instead.

Also fix the macro for s390x and use "psw.addr" from "pt_regs".

Reported-by: Zvonko Kosic 
Signed-off-by: Michael Holzheu 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

samples/bpf: add perf_event+bpf example

2016-09-02T17:46:45+00:00

The bpf program is called 50 times a second and does hashmap[kern&user_stackid]++
It's primary purpose to check that key bpf helpers like map lookup, update,
get_stackid, trace_printk and ctx access are all working.
It checks:
- PERF_COUNT_HW_CPU_CYCLES on all cpus
- PERF_COUNT_HW_CPU_CYCLES for current process and inherited perf_events to children
- PERF_COUNT_SW_CPU_CLOCK on all cpus
- PERF_COUNT_SW_CPU_CLOCK for current process

Signed-off-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

samples/bpf: Add tunnel set/get tests.

2016-08-20T05:42:44+00:00

The patch creates sample code exercising bpf_skb_{set,get}_tunnel_key,
and bpf_skb_{set,get}_tunnel_opt for GRE, VXLAN, and GENEVE.  A native
tunnel device is created in a namespace to interact with a lwtunnel
device out of the namespace, with metadata enabled.  The bpf_skb_set_*
program is attached to tc egress and bpf_skb_get_* is attached to egress
qdisc.  A ping between two tunnels is used to verify correctness and
the result of bpf_skb_get_* printed by bpf_trace_printk.

Signed-off-by: William Tu 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2016-08-18T05:17:32+00:00

Minor overlapping changes for both merge conflicts.

Resolution work done by Stephen Rothwell was used
as a reference.

Signed-off-by: David S. Miller

bpf: fix bpf_skb_in_cgroup helper naming

2016-08-13T04:53:33+00:00

While hashing out BPF's current_task_under_cgroup helper bits, it came
to discussion that the skb_in_cgroup helper name was suboptimally chosen.

Tejun says:

  So, I think in_cgroup should mean that the object is in that
  particular cgroup while under_cgroup in the subhierarchy of that
  cgroup. Let's rename the other subhierarchy test to under too. I
  think that'd be a lot less confusing going forward.

  [...]

  It's more intuitive and gives us the room to implement the real
  "in" test if ever necessary in the future.

Since this touches uapi bits, we need to change this as long as v4.8
is not yet officially released. Thus, change the helper enum and rename
related bits.

Fixes: 4a482f34afcc ("cgroup: bpf: Add bpf_skb_in_cgroup_proto")
Reference: http://patchwork.ozlabs.org/patch/658500/
Suggested-by: Sargun Dhillon 
Suggested-by: Tejun Heo 
Signed-off-by: Daniel Borkmann 
Acked-by: Alexei Starovoitov

samples/bpf: Add test_current_task_under_cgroup test

2016-08-13T04:49:42+00:00

This test has a BPF program which writes the last known pid to call the
sync syscall within a given cgroup to a map.

The user mode program creates its own mount namespace, and mounts the
cgroupsv2  hierarchy in there, as on all current test systems
(Ubuntu 16.04, Debian), the cgroupsv2 vfs is unmounted by default.
Once it does this, it proceeds to test.

The test checks for positive and negative condition. It ensures that
when it's part of a given cgroup, its pid is captured in the map,
and that when it leaves the cgroup, this doesn't happen.

It populate a cgroups arraymap prior to execution in userspace. This means
that the program must be run in the same cgroups namespace as the programs
that are being traced.

Signed-off-by: Sargun Dhillon 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Cc: Tejun Heo 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

samples/bpf: fix bpf_perf_event_output prototype

2016-08-11T06:12:31+00:00

The commit 555c8a8623a3 ("bpf: avoid stack copy and use skb ctx for event output")
started using 20 of initially reserved upper 32-bits of 'flags' argument
in bpf_perf_event_output(). Adjust corresponding prototype in samples/bpf/bpf_helpers.h

Signed-off-by: Adam Barth 
Signed-off-by: Alexei Starovoitov 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller

bpf: Add bpf_probe_write_user BPF helper to be called in tracers

2016-07-26T01:07:48+00:00

This allows user memory to be written to during the course of a kprobe.
It shouldn't be used to implement any kind of security mechanism
because of TOC-TOU attacks, but rather to debug, divert, and
manipulate execution of semi-cooperative processes.

Although it uses probe_kernel_write, we limit the address space
the probe can write into by checking the space with access_ok.
We do this as opposed to calling copy_to_user directly, in order
to avoid sleeping. In addition we ensure the threads's current fs
/ segment is USER_DS and the thread isn't exiting nor a kernel thread.

Given this feature is meant for experiments, and it has a risk of
crashing the system, and running programs, we print a warning on
when a proglet that attempts to use this helper is installed,
along with the pid and process name.

Signed-off-by: Sargun Dhillon 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

cgroup: bpf: Add an example to do cgroup checking in BPF

2016-07-01T20:32:13+00:00

test_cgrp2_array_pin.c:
A userland program that creates a bpf_map (BPF_MAP_TYPE_GROUP_ARRAY),
pouplates/updates it with a cgroup2's backed fd and pins it to a
bpf-fs's file.  The pinned file can be loaded by tc and then used
by the bpf prog later.  This program can also update an existing pinned
array and it could be useful for debugging/testing purpose.

test_cgrp2_tc_kern.c:
A bpf prog which should be loaded by tc.  It is to demonstrate
the usage of bpf_skb_in_cgroup.

test_cgrp2_tc.sh:
A script that glues the test_cgrp2_array_pin.c and
test_cgrp2_tc_kern.c together.  The idea is like:
1. Load the test_cgrp2_tc_kern.o by tc
2. Use test_cgrp2_array_pin.c to populate a BPF_MAP_TYPE_CGROUP_ARRAY
   with a cgroup fd
3. Do a 'ping -6 ff02::1%ve' to ensure the packet has been
   dropped because of a match on the cgroup

Most of the lines in test_cgrp2_tc.sh is the boilerplate
to setup the cgroup/bpf-fs/net-devices/netns...etc.  It is
not bulletproof on errors but should work well enough and
give enough debug info if things did not go well.

Signed-off-by: Martin KaFai Lau 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Cc: Tejun Heo 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

samples/bpf: Enable powerpc support

2016-04-06T20:01:29+00:00

Add the necessary definitions for building bpf samples on ppc.

Since ppc doesn't store function return address on the stack, modify how
PT_REGS_RET() and PT_REGS_FP() work.

Also, introduce PT_REGS_IP() to access the instruction pointer.

Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Cc: David S. Miller 
Cc: Ananth N Mavinakayanahalli 
Cc: Michael Ellerman 
Signed-off-by: Naveen N. Rao 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller