From: Peter Zijlstra <peterz@infradead.org>
To: Jiri Olsa <jolsa@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>,
Andrii Nakryiko <andrii@kernel.org>,
bpf@vger.kernel.org, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
Hao Luo <haoluo@google.com>, Steven Rostedt <rostedt@goodmis.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Alan Maguire <alan.maguire@oracle.com>,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH bpf-next 00/13] uprobes: Add support to optimize usdt probes on x86_64
Date: Fri, 13 Dec 2024 11:51:05 +0100 [thread overview]
Message-ID: <20241213105105.GB35539@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20241211133403.208920-1-jolsa@kernel.org>
On Wed, Dec 11, 2024 at 02:33:49PM +0100, Jiri Olsa wrote:
> hi,
> this patchset adds support to optimize usdt probes on top of 5-byte
> nop instruction.
>
> The generic approach (optimize all uprobes) is hard due to emulating
> possible multiple original instructions and its related issues. The
> usdt case, which stores 5-byte nop seems much easier, so starting
> with that.
>
> The basic idea is to replace breakpoint exception with syscall which
> is faster on x86_64. For more details please see changelog of patch 8.
So ideally we'd put a check in the syscall, which verifies it comes from
one of our trampolines and reject any and all other usage.
The reason to do this is that we can then delete all this code the
moment it becomes irrelevant without having to worry userspace might be
'creative' somewhere.
next prev parent reply other threads:[~2024-12-13 10:51 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-11 13:33 [PATCH bpf-next 00/13] uprobes: Add support to optimize usdt probes on x86_64 Jiri Olsa
2024-12-11 13:33 ` [PATCH bpf-next 01/13] uprobes: Rename arch_uretprobe_trampoline function Jiri Olsa
2024-12-13 0:42 ` Andrii Nakryiko
2024-12-11 13:33 ` [PATCH bpf-next 02/13] uprobes: Make copy_from_page global Jiri Olsa
2024-12-13 0:43 ` Andrii Nakryiko
2024-12-11 13:33 ` [PATCH bpf-next 03/13] uprobes: Add nbytes argument to uprobe_write_opcode Jiri Olsa
2024-12-13 0:45 ` Andrii Nakryiko
2024-12-11 13:33 ` [PATCH bpf-next 04/13] uprobes: Add arch_uprobe_verify_opcode function Jiri Olsa
2024-12-13 0:48 ` Andrii Nakryiko
2024-12-13 13:21 ` Jiri Olsa
2024-12-13 21:11 ` Andrii Nakryiko
2024-12-13 21:52 ` Jiri Olsa
2024-12-11 13:33 ` [PATCH bpf-next 05/13] uprobes: Add mapping for optimized uprobe trampolines Jiri Olsa
2024-12-13 1:01 ` Andrii Nakryiko
2024-12-13 13:42 ` Jiri Olsa
2024-12-13 21:58 ` Andrii Nakryiko
2024-12-11 13:33 ` [PATCH bpf-next 06/13] uprobes/x86: Add uprobe syscall to speed up uprobe Jiri Olsa
2024-12-13 13:48 ` Thomas Weißschuh
2024-12-13 14:51 ` Jiri Olsa
2024-12-13 15:12 ` Thomas Weißschuh
2024-12-13 21:52 ` Jiri Olsa
2024-12-14 13:21 ` Thomas Weißschuh
2024-12-16 8:03 ` Jiri Olsa
2024-12-11 13:33 ` [PATCH bpf-next 07/13] uprobes/x86: Add support to emulate nop5 instruction Jiri Olsa
2024-12-13 10:45 ` Peter Zijlstra
2024-12-13 13:02 ` Jiri Olsa
2024-12-11 13:33 ` [PATCH bpf-next 08/13] uprobes/x86: Add support to optimize uprobes Jiri Olsa
2024-12-13 10:49 ` Peter Zijlstra
2024-12-13 13:06 ` Jiri Olsa
2024-12-13 21:58 ` Andrii Nakryiko
2024-12-15 12:06 ` David Laight
2024-12-15 14:14 ` Oleg Nesterov
2024-12-16 8:08 ` Jiri Olsa
2024-12-16 9:18 ` David Laight
2024-12-16 10:12 ` Oleg Nesterov
2024-12-16 11:10 ` David Laight
2024-12-16 12:22 ` Oleg Nesterov
2024-12-16 12:50 ` Jiri Olsa
2024-12-16 15:08 ` David Laight
2024-12-16 16:06 ` Jiri Olsa
2024-12-11 13:33 ` [PATCH bpf-next 09/13] selftests/bpf: Use 5-byte nop for x86 usdt probes Jiri Olsa
2024-12-13 21:58 ` Andrii Nakryiko
2024-12-16 8:32 ` Jiri Olsa
2024-12-16 23:06 ` Andrii Nakryiko
2024-12-11 13:33 ` [PATCH bpf-next 10/13] selftests/bpf: Add uprobe/usdt optimized test Jiri Olsa
2024-12-13 21:58 ` Andrii Nakryiko
2024-12-16 7:58 ` Jiri Olsa
2024-12-11 13:34 ` [PATCH bpf-next 11/13] selftests/bpf: Add hit/attach/detach race optimized uprobe test Jiri Olsa
2024-12-13 21:58 ` Andrii Nakryiko
2024-12-16 7:59 ` Jiri Olsa
2024-12-11 13:34 ` [PATCH bpf-next 12/13] selftests/bpf: Add uprobe syscall sigill signal test Jiri Olsa
2024-12-11 13:34 ` [PATCH bpf-next 13/13] selftests/bpf: Add 5-byte nop uprobe trigger bench Jiri Olsa
2024-12-13 21:57 ` Andrii Nakryiko
2024-12-16 7:56 ` Jiri Olsa
2024-12-13 0:43 ` [PATCH bpf-next 00/13] uprobes: Add support to optimize usdt probes on x86_64 Andrii Nakryiko
2024-12-13 9:46 ` Jiri Olsa
2024-12-13 10:51 ` Peter Zijlstra [this message]
2024-12-13 13:07 ` Jiri Olsa
2024-12-13 13:54 ` Peter Zijlstra
2024-12-13 14:05 ` Jiri Olsa
2024-12-13 18:39 ` Peter Zijlstra
2024-12-13 21:52 ` Jiri Olsa
2024-12-13 21:59 ` Andrii Nakryiko
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