From: Alexei Starovoitov <ast@kernel.org>
To: <davem@davemloft.net>
Cc: <daniel@iogearbox.net>, <x86@kernel.org>,
<netdev@vger.kernel.org>, <bpf@vger.kernel.org>,
<kernel-team@fb.com>
Subject: [PATCH bpf-next 02/10] bpf: add typecast to bpf helpers to help BTF generation
Date: Fri, 4 Oct 2019 22:03:06 -0700 [thread overview]
Message-ID: <20191005050314.1114330-3-ast@kernel.org> (raw)
In-Reply-To: <20191005050314.1114330-1-ast@kernel.org>
When pahole converts dwarf to btf it emits only used types.
Wrap existing bpf helper functions into typedef and use it in
typecast to make gcc emits this type into dwarf.
Then pahole will convert it to btf.
The "btf_#name_of_helper" types will be used to figure out
types of arguments of bpf helpers.
The generate code before and after is the same.
Only dwarf and btf are different.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
include/linux/filter.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 2ce57645f3cd..d3d51d7aff2c 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -464,10 +464,11 @@ static inline bool insn_is_zext(const struct bpf_insn *insn)
#define BPF_CALL_x(x, name, ...) \
static __always_inline \
u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \
+ typedef u64 (*btf_##name)(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \
u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \
u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \
{ \
- return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\
+ return ((btf_##name)____##name)(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\
} \
static __always_inline \
u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__))
--
2.20.0
next prev parent reply other threads:[~2019-10-05 5:03 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-05 5:03 [PATCH bpf-next 00/10] bpf: revolutionize bpf tracing Alexei Starovoitov
2019-10-05 5:03 ` [PATCH bpf-next 01/10] bpf: add typecast to raw_tracepoints to help BTF generation Alexei Starovoitov
2019-10-05 18:40 ` Andrii Nakryiko
2019-10-06 3:58 ` John Fastabend
2019-10-05 5:03 ` Alexei Starovoitov [this message]
2019-10-05 18:41 ` [PATCH bpf-next 02/10] bpf: add typecast to bpf helpers " Andrii Nakryiko
2019-10-06 4:00 ` John Fastabend
2019-10-05 5:03 ` [PATCH bpf-next 03/10] bpf: process in-kernel BTF Alexei Starovoitov
2019-10-06 6:36 ` Andrii Nakryiko
2019-10-06 23:49 ` Alexei Starovoitov
2019-10-07 0:20 ` Andrii Nakryiko
2019-10-09 20:51 ` Martin Lau
2019-10-10 3:43 ` Alexei Starovoitov
2019-10-05 5:03 ` [PATCH bpf-next 04/10] libbpf: auto-detect btf_id of raw_tracepoint Alexei Starovoitov
2019-10-07 23:41 ` Andrii Nakryiko
2019-10-09 2:26 ` Alexei Starovoitov
2019-10-05 5:03 ` [PATCH bpf-next 05/10] bpf: implement accurate raw_tp context access via BTF Alexei Starovoitov
2019-10-07 16:32 ` Alan Maguire
2019-10-09 3:59 ` Alexei Starovoitov
2019-10-08 0:35 ` Andrii Nakryiko
2019-10-09 3:30 ` Alexei Starovoitov
2019-10-09 4:01 ` Andrii Nakryiko
2019-10-09 5:10 ` Andrii Nakryiko
2019-10-10 3:54 ` Alexei Starovoitov
2019-10-05 5:03 ` [PATCH bpf-next 06/10] bpf: add support for BTF pointers to interpreter Alexei Starovoitov
2019-10-08 3:08 ` Andrii Nakryiko
2019-10-05 5:03 ` [PATCH bpf-next 07/10] bpf: add support for BTF pointers to x86 JIT Alexei Starovoitov
2019-10-05 6:03 ` Eric Dumazet
2019-10-09 17:38 ` Andrii Nakryiko
2019-10-09 17:46 ` Alexei Starovoitov
2019-10-05 5:03 ` [PATCH bpf-next 08/10] bpf: check types of arguments passed into helpers Alexei Starovoitov
2019-10-09 18:01 ` Andrii Nakryiko
2019-10-09 19:58 ` Alexei Starovoitov
2019-10-05 5:03 ` [PATCH bpf-next 09/10] bpf: disallow bpf_probe_read[_str] helpers Alexei Starovoitov
2019-10-09 5:29 ` Andrii Nakryiko
2019-10-09 19:38 ` Alexei Starovoitov
2019-10-05 5:03 ` [PATCH bpf-next 10/10] selftests/bpf: add kfree_skb raw_tp test Alexei Starovoitov
2019-10-09 5:36 ` Andrii Nakryiko
2019-10-09 17:37 ` Alexei Starovoitov
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