linux.git/tools/lib/bpf/bpf.c, branch v4.10

bpf: introduce BPF_F_ALLOW_OVERRIDE flag

2017-02-13T02:52:19+00:00

If BPF_F_ALLOW_OVERRIDE flag is used in BPF_PROG_ATTACH command
to the given cgroup the descendent cgroup will be able to override
effective bpf program that was inherited from this cgroup.
By default it's not passed, therefore override is disallowed.

Examples:
1.
prog X attached to /A with default
prog Y fails to attach to /A/B and /A/B/C
Everything under /A runs prog X

2.
prog X attached to /A with allow_override.
prog Y fails to attach to /A/B with default (non-override)
prog M attached to /A/B with allow_override.
Everything under /A/B runs prog M only.

3.
prog X attached to /A with allow_override.
prog Y fails to attach to /A with default.
The user has to detach first to switch the mode.

In the future this behavior may be extended with a chain of
non-overridable programs.

Also fix the bug where detach from cgroup where nothing is attached
was not throwing error. Return ENOENT in such case.

Add several testcases and adjust libbpf.

Fixes: 3007098494be ("cgroup: add support for eBPF programs")
Signed-off-by: Alexei Starovoitov 
Acked-by: Daniel Borkmann 
Acked-by: Tejun Heo 
Acked-by: Daniel Mack 
Signed-off-by: David S. Miller

tools lib bpf: Add bpf_prog_{attach,detach}

2016-12-20T15:00:39+00:00

Commit d8c5b17f2bc0 ("samples: bpf: add userspace example for attaching
eBPF programs to cgroups") added these functions to samples/libbpf, but
during this merge all of the samples libbpf functionality is shifting to
tools/lib/bpf. Shift these functions there.

Committer notes:

Use bzero + attr.FIELD = value instead of 'attr = { .FIELD = value, just
like the other wrapper calls to sys_bpf with bpf_attr to make this build
in older toolchais, such as the ones in CentOS 5 and 6.

Signed-off-by: Joe Stringer 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-au2zvtsh55vqeo3v3uw7jr4c@git.kernel.org
Link: https://github.com/joestringer/linux/commit/353e6f298c3d0a92fa8bfa61ff898c5050261a12.patch
Signed-off-by: Arnaldo Carvalho de Melo

tools lib bpf: Add flags to bpf_create_map()

2016-12-15T19:25:47+00:00

Commit 6c905981743 ("bpf: pre-allocate hash map elements") introduces
map_flags to bpf_attr for BPF_MAP_CREATE command. Expose this new
parameter in libbpf.

By exposing it, users can access flags such as whether or not to
preallocate the map.

Signed-off-by: Joe Stringer 
Acked-by: Wang Nan 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Link: http://lkml.kernel.org/r/20161209024620.31660-4-joe@ovn.org
[ Added clarifying comment made by Wang Nan ]
Signed-off-by: Arnaldo Carvalho de Melo

tools lib bpf: use __u32 from linux/types.h

2016-12-15T19:25:46+00:00

Fixes the following issue when building without access to 'u32' type:

./tools/lib/bpf/bpf.h:27:23: error: unknown type name ‘u32’

Signed-off-by: Joe Stringer 
Acked-by: Wang Nan 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Link: http://lkml.kernel.org/r/20161209024620.31660-3-joe@ovn.org
Signed-off-by: Arnaldo Carvalho de Melo

tools lib bpf: Add missing BPF functions

2016-11-29T15:09:36+00:00

Add more BPF map operations to libbpf. Also add bpf_obj_{pin,get}(). They
can be used on not only BPF maps but also BPF programs.

Signed-off-by: Wang Nan 
Acked-by: Alexei Starovoitov 
Cc: He Kuang 
Cc: Joe Stringer 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/20161126070354.141764-2-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

tools lib bpf: Add license header

2016-07-04T23:27:25+00:00

Adding a missing license descriptopn header to files in libbpf, make it
LGPL-2.1.

Signed-off-by: Wang Nan 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Cc: Eric Leblond 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1467630162-193121-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix PowerPC native building

2016-01-11T22:22:20+00:00

Checks BPF syscall number, turn off libbpf building on platform doesn't
correctly support sys_bpf instead of blocking compiling.

Reported-and-Tested-by: Naveen N. Rao 
Signed-off-by: Wang Nan 
Acked-by: Jiri Olsa 
Cc: Sukadev Bhattiprolu 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1452520124-2073-7-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

bpf tools: Add helper function for updating bpf maps elements

2015-11-26T20:21:24+00:00

Add bpf_map_update_elem() helper function which calls the sys_bpf
syscall to update elements in bpf maps. Upcoming patches will use it to
adjust data in map through the perf command line.

Signed-off-by: He Kuang 
Cc: Alexei Starovoitov 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Wang Nan 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1448372181-151723-4-git-send-email-wangnan0@huawei.com
Signed-off-by: Wang Nan 
Signed-off-by: Arnaldo Carvalho de Melo

bpf tools: Introduce bpf_load_program() to bpf.c

2015-08-07T13:16:58+00:00

bpf_load_program() can be used to load bpf program into kernel. To make
loading faster, first try to load without logbuf. Try again with logbuf
if the first try failed.

Signed-off-by: Wang Nan 
Acked-by: Alexei Starovoitov 
Cc: Brendan Gregg 
Cc: Daniel Borkmann 
Cc: David Ahern 
Cc: He Kuang 
Cc: Jiri Olsa 
Cc: Kaixu Xia 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-19-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

bpf tools: Add bpf.c/h for common bpf operations

2015-08-07T13:16:58+00:00

This patch introduces bpf.c and bpf.h, which hold common functions
issuing bpf syscall. The goal of these two files is to hide syscall
completely from user. Note that bpf.c and bpf.h deal with kernel
interface only. Things like structure of 'map' section in the ELF object
is not cared by of bpf.[ch].

We first introduce bpf_create_map().

Note that, since functions in bpf.[ch] are wrapper of sys_bpf, they
don't use OO style naming.

Signed-off-by: Wang Nan 
Acked-by: Alexei Starovoitov 
Cc: Brendan Gregg 
Cc: Daniel Borkmann 
Cc: David Ahern 
Cc: He Kuang 
Cc: Jiri Olsa 
Cc: Kaixu Xia 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-16-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo