The way we're using kernel headers in tools/ now, with a copy that is
made to the same path prefixed by "tools/" plus checking if that copy
got stale, i.e. if the kernel counterpart changed, helps in keeping
track with new features that may be useful for tools to exploit.
For instance, looking at all the changes to bpf.h since it was last
copied to tools/include brings this to toolers' attention:
Need to investigate this one to check how to run a program via perf, setting up
a BPF event, that will take advantage of the way perf already calls clang/LLVM,
sets up the event and runs the workload in a single command line, helping in
debugging such semi cooperative programs:
96ae522795 ("bpf: Add bpf_probe_write_user BPF helper to be called in tracers")
This one needs further investigation about using the feature it improves
in 'perf trace' to do some tcpdumpin' mixed with syscalls, tracepoints,
probe points, callgraphs, etc:
555c8a8623 ("bpf: avoid stack copy and use skb ctx for event output")
Add tracing just packets that are related to some container to that mix:
4a482f34af ("cgroup: bpf: Add bpf_skb_in_cgroup_proto")
4ed8ec521e ("cgroup: bpf: Add BPF_MAP_TYPE_CGROUP_ARRAY")
Definetely needs to have example programs accessing task_struct from a bpf proggie
started from 'perf trace':
606274c5ab ("bpf: introduce bpf_get_current_task() helper")
Core networking related, XDP:
6ce96ca348 ("bpf: add XDP_TX xdp_action for direct forwarding")
6a773a15a1 ("bpf: add XDP prog type for early driver filter")
13c5c240f7 ("bpf: add bpf_get_hash_recalc helper")
d2485c4242 ("bpf: add bpf_skb_change_type helper")
6578171a7f ("bpf: add bpf_skb_change_proto helper")
Changes detected by the tools build system:
$ make -C tools/perf O=/tmp/build/perf install-bin
make: Entering directory '/home/acme/git/linux/tools/perf'
BUILD: Doing 'make -j4' parallel build
Warning: tools/include/uapi/linux/bpf.h differs from kernel
INSTALL GTK UI
CC /tmp/build/perf/bench/mem-memcpy-x86-64-asm.o
<SNIP>
$
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Brenden Blanco <bblanco@plumgrid.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Sargun Dhillon <sargun@sargun.me>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-difq4ts1xvww6eyfs9e7zlft@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We use it in bitops/__ffs.h and bitops/atomic.h, that we also got from
the kernel, but were getting it from either newer systems that carry it
in /usr/include, or from the kernel sources, that we decided not to
touch from tools/ code. Fix it.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-lwqvgbuitjmrdpjmjp6zqnyx@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To allow the build to complete on older systems, where those files are
either not uptodate, lacking some recent additions or not present at
all.
And check if the copy drifts from the kernel.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-3jz31pz4nw526uko5da9e7o3@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To allow the build to complete on older systems, where those files are
either not uptodate, lacking some recent additions or not present at
all.
And check if the copy drifts from the kernel, as in this synthetic test:
BUILD: Doing 'make -j4' parallel build
Warning: tools/include/linux/bpf.h differs from kernel
Warning: tools/include/linux/bpf_common.h differs from kernel
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-5plvi2gq4x469dcyybiu226q@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We shouldn't use headers from the kernel sources directly, instead we
should use the system's headers or in cases where that isn't possible,
like with perf_event.h, where the introduction of kernel features such
as perf_event_attr.{write_backwards,sample_max_stack} and
PERF_EVENT_IOC_PAUSE_OUTPUT take some time to become available in
/usr/include/linux/perf_event.h we need a copy.
Do it and check for source code drift, emitting a warning when changes
are detected.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-v6aks5un3s5pehory6f42nrl@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Arnaldo Carvalho de Melo