From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-111.freemail.mail.aliyun.com (out30-111.freemail.mail.aliyun.com [115.124.30.111]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A94C6A21; Sat, 23 Dec 2023 02:56:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R161e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045176;MF=lulie@linux.alibaba.com;NM=1;PH=DS;RN=22;SR=0;TI=SMTPD_---0Vz09Zi-_1703300143; Received: from 30.236.12.129(mailfrom:lulie@linux.alibaba.com fp:SMTPD_---0Vz09Zi-_1703300143) by smtp.aliyun-inc.com; Sat, 23 Dec 2023 10:56:41 +0800 Message-ID: Date: Sat, 23 Dec 2023 10:56:40 +0800 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH bpf-next 3/3] bpf: introduce bpf_relay_output helper To: Jiri Olsa Cc: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yonghong.song@linux.dev, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, linux-trace-kernel@vger.kernel.org, xuanzhuo@linux.alibaba.com, dust.li@linux.alibaba.com, alibuda@linux.alibaba.com, guwen@linux.alibaba.com, hengqi@linux.alibaba.com, shung-hsi.yu@suse.com References: <20231222122146.65519-1-lulie@linux.alibaba.com> <20231222122146.65519-4-lulie@linux.alibaba.com> From: Philo Lu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2023/12/22 22:46, Jiri Olsa wrote: > On Fri, Dec 22, 2023 at 08:21:46PM +0800, Philo Lu wrote: >> Like perfbuf/ringbuf, a helper is needed to write into the buffer, named >> bpf_relay_output, whose usage is same as ringbuf. Note that it works only >> after relay files are set, i.e., after calling map_update_elem for the >> created relay map. > > we can't add helpers anymore, this will need to be kfunc > check functions marked with __bpf_kfunc as examples > Got it, I will change it to kfunc in the next version. Thanks. > jirka > >> >> Signed-off-by: Philo Lu >> --- >> include/linux/bpf.h | 1 + >> include/uapi/linux/bpf.h | 10 ++++++++++ >> kernel/bpf/helpers.c | 4 ++++ >> kernel/bpf/relaymap.c | 26 ++++++++++++++++++++++++++ >> kernel/bpf/verifier.c | 8 ++++++++ >> kernel/trace/bpf_trace.c | 4 ++++ >> 6 files changed, 53 insertions(+) >> >> diff --git a/include/linux/bpf.h b/include/linux/bpf.h >> index 7671530d6e4e..b177122369e6 100644 >> --- a/include/linux/bpf.h >> +++ b/include/linux/bpf.h >> @@ -3095,6 +3095,7 @@ extern const struct bpf_func_proto bpf_get_retval_proto; >> extern const struct bpf_func_proto bpf_user_ringbuf_drain_proto; >> extern const struct bpf_func_proto bpf_cgrp_storage_get_proto; >> extern const struct bpf_func_proto bpf_cgrp_storage_delete_proto; >> +extern const struct bpf_func_proto bpf_relay_output_proto; >> >> const struct bpf_func_proto *tracing_prog_func_proto( >> enum bpf_func_id func_id, const struct bpf_prog *prog); >> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h >> index 143b75676bd3..03c0c1953ba1 100644 >> --- a/include/uapi/linux/bpf.h >> +++ b/include/uapi/linux/bpf.h >> @@ -5686,6 +5686,15 @@ union bpf_attr { >> * 0 on success. >> * >> * **-ENOENT** if the bpf_local_storage cannot be found. >> + * >> + * long bpf_relay_output(void *map, void *data, u64 size, u64 flags) >> + * Description >> + * Copy *size* bytes from *data* into *map* of type BPF_MAP_TYPE_RELAY. >> + * Currently, the *flags* must be 0. >> + * Return >> + * 0 on success. >> + * >> + * **-ENOENT** if the relay base_file in debugfs cannot be found. >> */ >> #define ___BPF_FUNC_MAPPER(FN, ctx...) \ >> FN(unspec, 0, ##ctx) \ >> @@ -5900,6 +5909,7 @@ union bpf_attr { >> FN(user_ringbuf_drain, 209, ##ctx) \ >> FN(cgrp_storage_get, 210, ##ctx) \ >> FN(cgrp_storage_delete, 211, ##ctx) \ >> + FN(relay_output, 212, ##ctx) \ >> /* */ >> >> /* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't >> diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c >> index be72824f32b2..0c26e87ce729 100644 >> --- a/kernel/bpf/helpers.c >> +++ b/kernel/bpf/helpers.c >> @@ -1720,6 +1720,10 @@ bpf_base_func_proto(enum bpf_func_id func_id) >> return &bpf_ringbuf_discard_proto; >> case BPF_FUNC_ringbuf_query: >> return &bpf_ringbuf_query_proto; >> +#ifdef CONFIG_RELAY >> + case BPF_FUNC_relay_output: >> + return &bpf_relay_output_proto; >> +#endif >> case BPF_FUNC_strncmp: >> return &bpf_strncmp_proto; >> case BPF_FUNC_strtol: >> diff --git a/kernel/bpf/relaymap.c b/kernel/bpf/relaymap.c >> index 588c8de0a4bd..f9e2e4a780df 100644 >> --- a/kernel/bpf/relaymap.c >> +++ b/kernel/bpf/relaymap.c >> @@ -173,6 +173,32 @@ static u64 relay_map_mem_usage(const struct bpf_map *map) >> return usage; >> } >> >> +BPF_CALL_4(bpf_relay_output, struct bpf_map *, map, void *, data, u64, size, >> + u64, flags) >> +{ >> + struct bpf_relay_map *rmap; >> + >> + /* not support any flag now */ >> + if (unlikely(flags)) >> + return -EINVAL; >> + >> + rmap = container_of(map, struct bpf_relay_map, map); >> + if (!rmap->relay_chan->has_base_filename) >> + return -ENOENT; >> + >> + relay_write(rmap->relay_chan, data, size); >> + return 0; >> +} >> + >> +const struct bpf_func_proto bpf_relay_output_proto = { >> + .func = bpf_relay_output, >> + .ret_type = RET_INTEGER, >> + .arg1_type = ARG_CONST_MAP_PTR, >> + .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, >> + .arg3_type = ARG_CONST_SIZE_OR_ZERO, >> + .arg4_type = ARG_ANYTHING, >> +}; >> + >> BTF_ID_LIST_SINGLE(relay_map_btf_ids, struct, bpf_relay_map) >> const struct bpf_map_ops relay_map_ops = { >> .map_meta_equal = bpf_map_meta_equal, >> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c >> index f13008d27f35..8c8287d6ae18 100644 >> --- a/kernel/bpf/verifier.c >> +++ b/kernel/bpf/verifier.c >> @@ -8800,6 +8800,10 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, >> if (func_id != BPF_FUNC_user_ringbuf_drain) >> goto error; >> break; >> + case BPF_MAP_TYPE_RELAY: >> + if (func_id != BPF_FUNC_relay_output) >> + goto error; >> + break; >> case BPF_MAP_TYPE_STACK_TRACE: >> if (func_id != BPF_FUNC_get_stackid) >> goto error; >> @@ -8932,6 +8936,10 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, >> if (map->map_type != BPF_MAP_TYPE_USER_RINGBUF) >> goto error; >> break; >> + case BPF_FUNC_relay_output: >> + if (map->map_type != BPF_MAP_TYPE_RELAY) >> + goto error; >> + break; >> case BPF_FUNC_get_stackid: >> if (map->map_type != BPF_MAP_TYPE_STACK_TRACE) >> goto error; >> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c >> index 7ac6c52b25eb..5b13553c6232 100644 >> --- a/kernel/trace/bpf_trace.c >> +++ b/kernel/trace/bpf_trace.c >> @@ -1594,6 +1594,10 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) >> return &bpf_ringbuf_discard_proto; >> case BPF_FUNC_ringbuf_query: >> return &bpf_ringbuf_query_proto; >> +#ifdef CONFIG_RELAY >> + case BPF_FUNC_relay_output: >> + return &bpf_relay_output_proto; >> +#endif >> case BPF_FUNC_jiffies64: >> return &bpf_jiffies64_proto; >> case BPF_FUNC_get_task_stack: >> -- >> 2.32.0.3.g01195cf9f >>