linux.git/samples/bpf/bpf_load.c, branch v4.12

samples/bpf: load_bpf.c make callback fixup more flexible

2017-05-03T13:30:24+00:00

Do this change before others start to use this callback.
Change map_perf_test_user.c which seems to be the only user.

This patch extends capabilities of commit 9fd63d05f3e8 ("bpf:
Allow bpf sample programs (*_user.c) to change bpf_map_def").

Give fixup callback access to struct bpf_map_data, instead of
only stuct bpf_map_def.  This add flexibility to allow userspace
to reassign the map file descriptor.  This is very useful when
wanting to share maps between several bpf programs.

Signed-off-by: Jesper Dangaard Brouer 
Signed-off-by: David S. Miller

samples/bpf: make bpf_load.c code compatible with ELF maps section changes

2017-05-03T13:30:24+00:00

This patch does proper parsing of the ELF "maps" section, in-order to
be both backwards and forwards compatible with changes to the map
definition struct bpf_map_def, which gets compiled into the ELF file.

The assumption is that new features with value zero, means that they
are not in-use.  For backward compatibility where loading an ELF file
with a smaller struct bpf_map_def, only copy objects ELF size, leaving
rest of loaders struct zero.  For forward compatibility where ELF file
have a larger struct bpf_map_def, only copy loaders own struct size
and verify that rest of the larger struct is zero, assuming this means
the newer feature was not activated, thus it should be safe for this
older loader to load this newer ELF file.

Fixes: fb30d4b71214 ("bpf: Add tests for map-in-map")
Fixes: 409526bea3c3 ("samples/bpf: bpf_load.c detect and abort if ELF maps section size is wrong")
Signed-off-by: Jesper Dangaard Brouer 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

samples/bpf: fix SKB_MODE flag to be a 32-bit unsigned int

2017-05-01T14:42:37+00:00

The kernel side of XDP_FLAGS_SKB_MODE is unsigned, and the rtnetlink
IFLA_XDP_FLAGS is defined as NLA_U32. Thus, userspace programs under
samples/bpf/ should use the correct type.

Fixes: 3993f2cb983b ("samples/bpf: Add support for SKB_MODE to xdp1 and xdp_tx_iptunnel")
Signed-off-by: Jesper Dangaard Brouer 
Acked-by: Daniel Borkmann 
Reviewed-by: Andy Gospodarek 
Signed-off-by: David S. Miller

samples/bpf: bpf_load.c detect and abort if ELF maps section size is wrong

2017-05-01T02:41:59+00:00

The struct bpf_map_def was extended in commit fb30d4b71214 ("bpf: Add tests
for map-in-map") with member unsigned int inner_map_idx.  This changed the size
of the maps section in the generated ELF _kern.o files.

Unfortunately the loader in bpf_load.c does not detect or handle this.  Thus,
older _kern.o files became incompatible, and caused hard-to-debug errors
where the syscall validation rejected BPF_MAP_CREATE request.

This patch only detect the situation and aborts load_bpf_file(). It also
add code comments warning people that read this loader for inspiration
for these pitfalls.

Fixes: fb30d4b71214 ("bpf: Add tests for map-in-map")
Signed-off-by: Jesper Dangaard Brouer 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

samples/bpf: Add support for SKB_MODE to xdp1 and xdp_tx_iptunnel

2017-04-27T16:49:26+00:00

Add option to xdp1 and xdp_tx_iptunnel to insert xdp program in
SKB_MODE:
 - update set_link_xdp_fd to take a flags argument that is added to the
   RTM_SETLINK message

 - Add -S option to xdp1 and xdp_tx_iptunnel user code. When passed in
   XDP_FLAGS_SKB_MODE is set in the flags arg passed to set_link_xdp_fd

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

bpf: Allow bpf sample programs (*_user.c) to change bpf_map_def

2017-04-17T17:55:52+00:00

The current bpf_map_def is statically defined during compile
time.  This patch allows the *_user.c program to change it during
runtime.  It is done by adding load_bpf_file_fixup_map() which
takes a callback.  The callback will be called before creating
each map so that it has a chance to modify the bpf_map_def.

The current usecase is to change max_entries in map_perf_test.
It is interesting to test with a much bigger map size in
some cases (e.g. the following patch on bpf_lru_map.c).
However,  it is hard to find one size to fit all testing
environment.  Hence, it is handy to take the max_entries
as a cmdline arg and then configure the bpf_map_def during
runtime.

This patch adds two cmdline args.  One is to configure
the map's max_entries.  Another is to configure the max_cnt
which controls how many times a syscall is called.

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

bpf: Add tests for map-in-map

2017-03-22T22:45:45+00:00

Test cases for array of maps and hash of maps.

Signed-off-by: Martin KaFai Lau 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

samples/bpf: Reset global variables

2017-02-13T20:22:53+00:00

Before loading a new ELF, clean previous kernel version, license and
processed sections.

Signed-off-by: Mickaël Salaün 
Acked-by: Joe Stringer 
Acked-by: Wang Nan 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Cc: David S. Miller 
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20170208202744.16274-3-mic@digikod.net
Signed-off-by: Arnaldo Carvalho de Melo

samples/bpf: Ignore already processed ELF sections

2017-02-13T20:22:47+00:00

Add a missing check for the map fixup loop.

Signed-off-by: Mickaël Salaün 
Acked-by: Joe Stringer 
Acked-by: Wang Nan 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Cc: David S. Miller 
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20170208202744.16274-2-mic@digikod.net
Signed-off-by: Arnaldo Carvalho de Melo

samples/bpf: Remove perf_event_open() declaration

2016-12-20T15:00:40+00:00

This declaration was made in samples/bpf/libbpf.c for convenience, but
there's already one in tools/perf/perf-sys.h. Reuse that one.

Committer notes:

Testing it:

  $ make -j4 O=../build/v4.9.0-rc8+ samples/bpf/
  make[1]: Entering directory '/home/build/v4.9.0-rc8+'
    CHK     include/config/kernel.release
    GEN     ./Makefile
    CHK     include/generated/uapi/linux/version.h
    Using /home/acme/git/linux as source for kernel
    CHK     include/generated/utsrelease.h
    CHK     include/generated/timeconst.h
    CHK     include/generated/bounds.h
    CHK     include/generated/asm-offsets.h
    CALL    /home/acme/git/linux/scripts/checksyscalls.sh
    HOSTCC  samples/bpf/test_verifier.o
    HOSTCC  samples/bpf/libbpf.o
    HOSTCC  samples/bpf/../../tools/lib/bpf/bpf.o
    HOSTCC  samples/bpf/test_maps.o
    HOSTCC  samples/bpf/sock_example.o
    HOSTCC  samples/bpf/bpf_load.o

    HOSTLD  samples/bpf/trace_event
    HOSTLD  samples/bpf/sampleip
    HOSTLD  samples/bpf/tc_l2_redirect
  make[1]: Leaving directory '/home/build/v4.9.0-rc8+'
  $

Also tested the offwaketime resulting from the rebuild, seems to work as
before.

Signed-off-by: Joe Stringer 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Cc: Wang Nan 
Link: http://lkml.kernel.org/r/20161209024620.31660-7-joe@ovn.org
[ Use -I$(srctree)/tools/lib/ to support out of source code tree builds ]
Signed-off-by: Arnaldo Carvalho de Melo