From: Jiri Olsa <olsajiri@gmail.com>
To: Yafang Shao <laoar.shao@gmail.com>
Cc: ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com,
andrii@kernel.org, martin.lau@linux.dev, song@kernel.org,
yhs@fb.com, kpsingh@kernel.org, sdf@google.com,
haoluo@google.com, quentin@isovalent.com, rostedt@goodmis.org,
mhiramat@kernel.org, bpf@vger.kernel.org,
linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH v3 bpf-next 01/10] bpf: Support ->fill_link_info for kprobe_multi
Date: Thu, 15 Jun 2023 10:29:10 +0200 [thread overview]
Message-ID: <ZIrL1szyBiYokMUy@krava> (raw)
In-Reply-To: <20230612151608.99661-2-laoar.shao@gmail.com>
On Mon, Jun 12, 2023 at 03:15:59PM +0000, Yafang Shao wrote:
SNIP
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index 2bc41e6..742047c 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -2548,9 +2548,36 @@ static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
> kfree(kmulti_link);
> }
>
> +static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link,
> + struct bpf_link_info *info)
> +{
> + u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs);
> + struct bpf_kprobe_multi_link *kmulti_link;
> + u32 ucount = info->kprobe_multi.count;
> +
> + if (!uaddrs ^ !ucount)
> + return -EINVAL;
> +
> + kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
> + if (!uaddrs) {
> + info->kprobe_multi.count = kmulti_link->cnt;
> + return 0;
> + }
> +
> + if (ucount < kmulti_link->cnt)
> + return -EINVAL;
> + info->kprobe_multi.flags = kmulti_link->fp.flags;
> + if (!kallsyms_show_value(current_cred()))
> + return 0;
> + if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64)))
> + return -EFAULT;
> + return 0;
> +}
> +
> static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
> .release = bpf_kprobe_multi_link_release,
> .dealloc = bpf_kprobe_multi_link_dealloc,
> + .fill_link_info = bpf_kprobe_multi_link_fill_link_info,
> };
>
> static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
> @@ -2890,6 +2917,7 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
> return err;
> }
>
> + link->fp.flags = flags;
hum this looks wrong, we can't use fprobe flags to store our flags
you should add flags to bpf_kprobe_multi_link
jirka
> return bpf_link_settle(&link_primer);
>
> error:
> diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
> index a7b5e91..23691ea 100644
> --- a/tools/include/uapi/linux/bpf.h
> +++ b/tools/include/uapi/linux/bpf.h
> @@ -6438,6 +6438,11 @@ struct bpf_link_info {
> __s32 priority;
> __u32 flags;
> } netfilter;
> + struct {
> + __aligned_u64 addrs; /* in/out: addresses buffer ptr */
> + __u32 count;
> + __u32 flags;
> + } kprobe_multi;
> };
> } __attribute__((aligned(8)));
>
> --
> 1.8.3.1
>
next prev parent reply other threads:[~2023-06-15 8:29 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-12 15:15 [PATCH v3 bpf-next 00/10] bpf: Support ->fill_link_info for kprobe_multi and perf_event links Yafang Shao
2023-06-12 15:15 ` [PATCH v3 bpf-next 01/10] bpf: Support ->fill_link_info for kprobe_multi Yafang Shao
2023-06-15 8:29 ` Jiri Olsa [this message]
2023-06-15 12:09 ` Yafang Shao
2023-06-16 17:24 ` Andrii Nakryiko
2023-06-17 2:48 ` Yafang Shao
2023-06-12 15:16 ` [PATCH v3 bpf-next 02/10] bpftool: Dump the kernel symbol's module name Yafang Shao
2023-06-13 13:41 ` Quentin Monnet
2023-06-13 14:56 ` Yafang Shao
2023-06-16 17:25 ` Andrii Nakryiko
2023-06-17 2:55 ` Yafang Shao
2023-06-12 15:16 ` [PATCH v3 bpf-next 03/10] bpftool: Show probed function in kprobe_multi link info Yafang Shao
2023-06-13 13:41 ` Quentin Monnet
2023-06-13 14:59 ` Yafang Shao
2023-06-13 22:36 ` Kui-Feng Lee
2023-06-14 2:42 ` Yafang Shao
2023-06-14 8:33 ` Quentin Monnet
2023-06-16 17:30 ` Andrii Nakryiko
2023-06-17 3:08 ` Yafang Shao
2023-06-20 17:17 ` Andrii Nakryiko
2023-06-21 1:29 ` Yafang Shao
2023-06-12 15:16 ` [PATCH v3 bpf-next 04/10] bpf: Protect probed address based on kptr_restrict setting Yafang Shao
2023-06-12 15:16 ` [PATCH v3 bpf-next 05/10] bpf: Clear the probe_addr for uprobe Yafang Shao
2023-06-12 17:22 ` Yonghong Song
2023-06-12 15:16 ` [PATCH v3 bpf-next 06/10] bpf: Expose symbol's respective address Yafang Shao
2023-06-12 15:16 ` [PATCH v3 bpf-next 07/10] bpf: Add a common helper bpf_copy_to_user() Yafang Shao
2023-06-12 15:16 ` [PATCH v3 bpf-next 08/10] bpf: Support ->fill_link_info for perf_event Yafang Shao
2023-06-12 17:36 ` Yonghong Song
2023-06-13 2:47 ` Yafang Shao
2023-06-14 2:34 ` Kui-Feng Lee
2023-06-14 2:45 ` Yafang Shao
2023-06-16 20:36 ` Andrii Nakryiko
2023-06-17 3:13 ` Yafang Shao
2023-06-15 10:21 ` Jiri Olsa
2023-06-15 12:10 ` Yafang Shao
2023-06-12 15:16 ` [PATCH v3 bpf-next 09/10] bpftool: Add perf event names Yafang Shao
2023-06-13 13:41 ` Quentin Monnet
2023-06-13 15:01 ` Yafang Shao
2023-06-15 10:23 ` Jiri Olsa
2023-06-12 15:16 ` [PATCH v3 bpf-next 10/10] bpftool: Show probed function in perf_event link info Yafang Shao
2023-06-13 13:42 ` Quentin Monnet
2023-06-13 15:11 ` Yafang Shao
2023-06-16 20:41 ` Andrii Nakryiko
2023-06-17 3:20 ` Yafang Shao
2023-06-17 3:29 ` Yafang Shao
2023-06-15 10:04 ` [PATCH v3 bpf-next 00/10] bpf: Support ->fill_link_info for kprobe_multi and perf_event links Jiri Olsa
2023-06-15 12:09 ` Yafang Shao
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