linux/include/trace
Andrii Nakryiko 441420a1f0 bpf: Reliably preserve btf_trace_xxx types
btf_trace_xxx types, crucial for tp_btf BPF programs (raw tracepoint with
verifier-checked direct memory access), have to be preserved in kernel BTF to
allow verifier do its job and enforce type/memory safety. It was reported
([0]) that for kernels built with Clang current type-casting approach doesn't
preserve these types.

This patch fixes it by declaring an anonymous union for each registered
tracepoint, capturing both struct bpf_raw_event_map information, as well as
recording btf_trace_##call type reliably. Structurally, it's still the same
content as for a plain struct bpf_raw_event_map, so no other changes are
necessary.

  [0] https://github.com/iovisor/bcc/issues/2770#issuecomment-591007692

Fixes: e8c423fb31 ("bpf: Add typecast to raw_tracepoints to help BTF generation")
Reported-by: Wenbo Zhang <ethercflow@gmail.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200301081045.3491005-2-andriin@fb.com
2020-03-02 16:49:55 -08:00
..
events ARM: SoC-related driver updates 2020-02-08 14:04:19 -08:00
bpf_probe.h bpf: Reliably preserve btf_trace_xxx types 2020-03-02 16:49:55 -08:00
define_trace.h tracing: introduce TRACE_EVENT_NOP() 2019-04-08 09:22:51 -04:00
perf.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
syscall.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_events.h Tracing updates: 2020-02-06 07:12:11 +00:00