linux/tools/lib/bpf, branch v4.20

libbpf: Fix compile error in libbpf_attach_type_by_name

2018-10-31T22:06:17Z

Arnaldo Carvalho de Melo reported build error in libbpf when clang version 3.8.1-24 (tags/RELEASE_381/final) is used: libbpf.c:2201:36: error: comparison of constant -22 with expression of type 'const enum bpf_attach_type' is always false [-Werror,-Wtautological-constant-out-of-range-compare] if (section_names[i].attach_type == -EINVAL) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~ 1 error generated. Fix the error by keeping "is_attachable" property of a program in a separate struct field instead of trying to use attach_type itself. Fixes: 956b620fcf0b ("libbpf: Introduce libbpf_attach_type_by_name") Reported-by: Arnaldo Carvalho de Melo Signed-off-by: Andrey Ignatov Tested-by: Arnaldo Carvalho de Melo Signed-off-by: Daniel Borkmann

bpf, libbpf: simplify and cleanup perf ring buffer walk

2018-10-21T06:13:32Z

Simplify bpf_perf_event_read_simple() a bit and fix up some minor things along the way: the return code in the header is not of type int but enum bpf_perf_event_ret instead. Once callback indicated to break the loop walking event data, it also needs to be consumed in data_tail since it has been processed already. Moreover, bpf_perf_event_print_t callback should avoid void * as we actually get a pointer to struct perf_event_header and thus applications can make use of container_of() to have type checks. The walk also doesn't have to use modulo op since the ring size is required to be power of two. Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov

bpf, libbpf: use correct barriers in perf ring buffer walk

2018-10-19T20:43:08Z

Given libbpf is a generic library and not restricted to x86-64 only, the compiler barrier in bpf_perf_event_read_simple() after fetching the head needs to be replaced with smp_rmb() at minimum. Also, writing out the tail we should use WRITE_ONCE() to avoid store tearing. Now that we have the logic in place in ring_buffer_read_head() and ring_buffer_write_tail() helper also used by perf tool which would select the correct and best variant for a given architecture (e.g. x86-64 can avoid CPU barriers entirely), make use of these in order to fix bpf_perf_event_read_simple(). Fixes: d0cabbb021be ("tools: bpf: move the event reading loop to libbpf") Fixes: 39111695b1b8 ("samples: bpf: add bpf_perf_event_output example") Signed-off-by: Daniel Borkmann Cc: Peter Zijlstra Cc: "Paul E. McKenney" Cc: Will Deacon Cc: Arnaldo Carvalho de Melo Signed-off-by: Alexei Starovoitov

selftests/bpf: add test cases for queue and stack maps

2018-10-19T20:24:31Z

test_maps: Tests that queue/stack maps are behaving correctly even in corner cases test_progs: Tests new ebpf helpers Signed-off-by: Mauricio Vasquez B Acked-by: Song Liu Signed-off-by: Alexei Starovoitov

libbpf: Per-symbol visibility for DSO

2018-10-16T22:16:47Z

Make global symbols in libbpf DSO hidden by default with -fvisibility=hidden and export symbols that are part of ABI explicitly with __attribute__((visibility("default"))). This is common practice that should prevent from accidentally exporting a symbol, that is not supposed to be a part of ABI what, in turn, improves both libbpf developer- and user-experiences. See [1] for more details. Export control becomes more important since more and more projects use libbpf. The patch doesn't export a bunch of netlink related functions since as agreed in [2] they'll be reworked. That doesn't break bpftool since bpftool links libbpf statically. [1] https://www.akkadia.org/drepper/dsohowto.pdf (2.2 Export Control) [2] https://www.mail-archive.com/netdev@vger.kernel.org/msg251434.html Signed-off-by: Andrey Ignatov Signed-off-by: Alexei Starovoitov

bpf: bpftool, add flag to allow non-compat map definitions

2018-10-15T23:13:14Z

Multiple map definition structures exist and user may have non-zero fields in their definition that are not recognized by bpftool and libbpf. The normal behavior is to then fail loading the map. Although this is a good default behavior users may still want to load the map for debugging or other reasons. This patch adds a --mapcompat flag that can be used to override the default behavior and allow loading the map even when it has additional non-zero fields. For now the only user is 'bpftool prog' we can switch over other subcommands as needed. The library exposes an API that consumes a flags field now but I kept the original API around also in case users of the API don't want to expose this. The flags field is an int in case we need more control over how the API call handles errors/features/etc in the future. Signed-off-by: John Fastabend Acked-by: Jakub Kicinski Signed-off-by: Alexei Starovoitov

tools/bpf: use proper type and uapi perf_event.h header for libbpf

2018-10-10T05:03:28Z

Use __u32 instead u32 in libbpf.c and also use uapi perf_event.h instead of tools/perf/perf-sys.h. Signed-off-by: Yonghong Song Acked-by: Song Liu Signed-off-by: Alexei Starovoitov

libbpf: relicense libbpf as LGPL-2.1 OR BSD-2-Clause

2018-10-08T08:09:48Z

libbpf is maturing as a library and gaining features that no other bpf libraries support (BPF Type Format, bpf to bpf calls, etc) Many Apache2 licensed projects (like bcc, bpftrace, gobpf, cilium, etc) would like to use libbpf, but cannot do this yet, since Apache Foundation explicitly states that LGPL is incompatible with Apache2. Hence let's relicense libbpf as dual license LGPL-2.1 or BSD-2-Clause, since BSD-2 is compatible with Apache2. Dual LGPL or Apache2 is invalid combination. Fix license mistake in Makefile as well. Signed-off-by: Alexei Starovoitov Acked-by: Andrey Ignatov Acked-by: Arnaldo Carvalho de Melo Acked-by: Björn Töpel Acked-by: Daniel Borkmann Acked-by: David Beckett Acked-by: Jakub Kicinski Acked-by: Joe Stringer Acked-by: John Fastabend Acked-by: Martin KaFai Lau Acked-by: Quentin Monnet Acked-by: Thomas Graf Acked-by: Roman Gushchin Acked-by: Wang Nan Acked-by: Yonghong Song Signed-off-by: Daniel Borkmann

libbpf: Use __u32 instead of u32 in bpf_program__load

2018-10-04T14:04:16Z

Make bpf_program__load consistent with other interfaces: use __u32 instead of u32. That in turn fixes build of samples: In file included from ./samples/bpf/trace_output_user.c:21:0: ./tools/lib/bpf/libbpf.h:132:9: error: unknown type name ‘u32’ u32 kern_version); ^ Fixes: commit 29cd77f41620d ("libbpf: Support loading individual progs") Signed-off-by: Andrey Ignatov Acked-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann

libbpf: Make include guards consistent

2018-10-04T14:04:16Z

Rename include guards to have consistent names "__LIBBPF_". Signed-off-by: Andrey Ignatov Acked-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann