From: Alexei Starovoitov <ast@fb.com>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>,
Alexei Starovoitov <ast@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>,
Daniel Borkmann <daniel@iogearbox.net>,
"x86@kernel.org" <x86@kernel.org>,
Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
Kernel Team <Kernel-team@fb.com>
Subject: Re: [PATCH v3 bpf-next 04/11] bpf: add attach_btf_id attribute to program load
Date: Wed, 16 Oct 2019 19:50:06 +0000 [thread overview]
Message-ID: <0cf37771-f23e-e165-8c73-8cb5fb3e7f22@fb.com> (raw)
In-Reply-To: <CAEf4BzZCw5_GESsziVg9fxj17ti3h-FjBNcZjaSDspwbT=i0fQ@mail.gmail.com>
On 10/16/19 12:45 PM, Andrii Nakryiko wrote:
> On Wed, Oct 16, 2019 at 4:15 AM Alexei Starovoitov <ast@kernel.org> wrote:
>>
>> Add attach_btf_id attribute to prog_load command.
>> It's similar to existing expected_attach_type attribute which is
>> used in several cgroup based program types.
>> Unfortunately expected_attach_type is ignored for
>> tracing programs and cannot be reused for new purpose.
>> Hence introduce attach_btf_id to verify bpf programs against
>> given in-kernel BTF type id at load time.
>> It is strictly checked to be valid for raw_tp programs only.
>> In a later patches it will become:
>> btf_id == 0 semantics of existing raw_tp progs.
>> btd_id > 0 raw_tp with BTF and additional type safety.
>>
>> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
>> Acked-by: Andrii Nakryiko <andriin@fb.com>
>> ---
>> include/linux/bpf.h | 1 +
>> include/uapi/linux/bpf.h | 1 +
>> kernel/bpf/syscall.c | 18 ++++++++++++++----
>> tools/include/uapi/linux/bpf.h | 1 +
>> 4 files changed, 17 insertions(+), 4 deletions(-)
>>
>> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
>> index 282e28bf41ec..f916380675dd 100644
>> --- a/include/linux/bpf.h
>> +++ b/include/linux/bpf.h
>> @@ -375,6 +375,7 @@ struct bpf_prog_aux {
>> u32 id;
>> u32 func_cnt; /* used by non-func prog as the number of func progs */
>> u32 func_idx; /* 0 for non-func prog, the index in func array for func prog */
>> + u32 attach_btf_id; /* in-kernel BTF type id to attach to */
>> bool verifier_zext; /* Zero extensions has been inserted by verifier. */
>> bool offload_requested;
>> struct bpf_prog **func;
>> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
>> index a65c3b0c6935..3bb2cd1de341 100644
>> --- a/include/uapi/linux/bpf.h
>> +++ b/include/uapi/linux/bpf.h
>> @@ -420,6 +420,7 @@ union bpf_attr {
>> __u32 line_info_rec_size; /* userspace bpf_line_info size */
>> __aligned_u64 line_info; /* line info */
>> __u32 line_info_cnt; /* number of bpf_line_info records */
>> + __u32 attach_btf_id; /* in-kernel BTF type id to attach to */
>> };
>>
>> struct { /* anonymous struct used by BPF_OBJ_* commands */
>> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
>> index 82eabd4e38ad..b56c482c9760 100644
>> --- a/kernel/bpf/syscall.c
>> +++ b/kernel/bpf/syscall.c
>> @@ -23,6 +23,7 @@
>> #include <linux/timekeeping.h>
>> #include <linux/ctype.h>
>> #include <linux/nospec.h>
>> +#include <uapi/linux/btf.h>
>>
>> #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \
>> (map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
>> @@ -1565,8 +1566,9 @@ static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
>> }
>>
>> static int
>> -bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type,
>> - enum bpf_attach_type expected_attach_type)
>> +bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
>> + enum bpf_attach_type expected_attach_type,
>> + u32 btf_id)
>> {
>> switch (prog_type) {
>> case BPF_PROG_TYPE_CGROUP_SOCK:
>> @@ -1608,13 +1610,19 @@ bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type,
>> default:
>> return -EINVAL;
>> }
>> + case BPF_PROG_TYPE_RAW_TRACEPOINT:
>> + if (btf_id > BTF_MAX_TYPE)
>> + return -EINVAL;
>> + return 0;
>> default:
>> + if (btf_id)
>> + return -EINVAL;
>
> this is minor issue, feel free to fix in a follow up patch, but this
> check should be done for all cases but BPF_PROG_TYPE_RAW_TRACEPOINT,
> not just for default (default will ignore a bunch of cgroup attach
> types).
right. good point. will fix in follow up if there are no issues in the
rest of patches.
next prev parent reply other threads:[~2019-10-16 19:50 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-16 3:24 [PATCH v3 bpf-next 00/11] bpf: revolutionize bpf tracing Alexei Starovoitov
2019-10-16 3:24 ` [PATCH v3 bpf-next 01/11] bpf: add typecast to raw_tracepoints to help BTF generation Alexei Starovoitov
2019-10-16 3:24 ` [PATCH v3 bpf-next 02/11] bpf: add typecast to bpf helpers " Alexei Starovoitov
2019-10-16 3:24 ` [PATCH v3 bpf-next 03/11] bpf: process in-kernel BTF Alexei Starovoitov
2019-10-16 3:24 ` [PATCH v3 bpf-next 04/11] bpf: add attach_btf_id attribute to program load Alexei Starovoitov
2019-10-16 19:45 ` Andrii Nakryiko
2019-10-16 19:50 ` Alexei Starovoitov [this message]
2019-10-16 3:24 ` [PATCH v3 bpf-next 05/11] libbpf: auto-detect btf_id of BTF-based raw_tracepoints Alexei Starovoitov
2019-10-16 19:49 ` Andrii Nakryiko
2019-10-16 3:25 ` [PATCH v3 bpf-next 06/11] bpf: implement accurate raw_tp context access via BTF Alexei Starovoitov
2019-10-16 20:09 ` Andrii Nakryiko
2019-10-16 21:21 ` Daniel Borkmann
2019-10-16 21:28 ` Alexei Starovoitov
2019-10-16 22:08 ` Daniel Borkmann
2019-10-16 23:52 ` Alexei Starovoitov
2019-10-16 3:25 ` [PATCH v3 bpf-next 07/11] bpf: attach raw_tp program with BTF via type name Alexei Starovoitov
2019-10-16 20:13 ` Andrii Nakryiko
2019-10-16 3:25 ` [PATCH v3 bpf-next 08/11] bpf: add support for BTF pointers to interpreter Alexei Starovoitov
2019-10-16 3:25 ` [PATCH v3 bpf-next 09/11] bpf: add support for BTF pointers to x86 JIT Alexei Starovoitov
2019-10-16 20:15 ` Andrii Nakryiko
2019-10-16 3:25 ` [PATCH v3 bpf-next 10/11] bpf: check types of arguments passed into helpers Alexei Starovoitov
2019-10-16 3:25 ` [PATCH v3 bpf-next 11/11] selftests/bpf: add kfree_skb raw_tp test Alexei Starovoitov
2019-10-16 18:01 ` [PATCH v3 bpf-next 00/11] bpf: revolutionize bpf tracing Martin Lau
2019-10-17 15:14 ` Daniel Borkmann
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