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From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>, bpf <bpf@vger.kernel.org>,
	Oleg Nesterov <oleg@redhat.com>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
	"David S. Miller" <davem@davemloft.net>, X86 ML <x86@kernel.org>,
	Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: Why do kprobes and uprobes singlestep?
Date: Tue, 2 Mar 2021 17:22:30 -0800	[thread overview]
Message-ID: <CAADnVQJtpvB8wDFv46O0GEaHkwmT1Ea70BJfgS36kDX0u4uZ-g@mail.gmail.com> (raw)
In-Reply-To: <EECBE373-7CA1-4ED8-9F03-406BBED607FD@amacapital.net>

On Tue, Mar 2, 2021 at 1:02 PM Andy Lutomirski <luto@amacapital.net> wrote:
>
>
> > On Mar 2, 2021, at 12:24 PM, Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:
> >
> > On Tue, Mar 2, 2021 at 10:38 AM Andy Lutomirski <luto@kernel.org> wrote:
> >>
> >> Is there something like a uprobe test suite?  How maintained /
> >> actively used is uprobe?
> >
> > uprobe+bpf is heavily used in production.
> > selftests/bpf has only one test for it though.
> >
> > Why are you asking?
>
> Because the integration with the x86 entry code is a mess, and I want to know whether to mark it BROKEN or how to make sure the any cleanups actually work.

Any test case to repro the issue you found?
Is it a bug or just messy code?
Nowadays a good chunk of popular applications (python, mysql, etc) has
USDTs in them.
Issues reported with bcc:
https://github.com/iovisor/bcc/issues?q=is%3Aissue+USDT
Similar thing with bpftrace.
Both standard USDT and semaphore based are used in the wild.
uprobe for containers has been a long standing feature request.
If you can improve uprobe performance that would be awesome.
That's another thing that people report often. We optimized it a bit.
More can be done.

  reply	other threads:[~2021-03-03 11:12 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-23 23:24 Why do kprobes and uprobes singlestep? Andy Lutomirski
2021-02-24  1:17 ` Masami Hiramatsu
2021-02-24 19:45   ` Andy Lutomirski
2021-02-25  2:22     ` Masami Hiramatsu
2021-02-25  6:03       ` Andy Lutomirski
2021-02-25  9:11         ` Masami Hiramatsu
2021-03-01 14:08       ` [RFC PATCH 0/1] x86/kprobes: Remoev single-step trap from x86 kprobes Masami Hiramatsu
2021-03-01 14:08         ` [RFC PATCH 1/1] x86/kprobes: Use int3 instead of debug trap for single-step Masami Hiramatsu
2021-03-02  8:06           ` Peter Zijlstra
2021-03-02  8:38           ` Peter Zijlstra
2021-03-02  8:41           ` Peter Zijlstra
2021-03-02  8:54             ` Peter Zijlstra
2021-03-02 12:51               ` Masami Hiramatsu
2021-03-02 13:58               ` Peter Zijlstra
2021-03-02 15:25       ` [PATCH -tip 0/3] x86/kprobes: Remoev single-step trap from x86 kprobes Masami Hiramatsu
2021-03-02 15:25         ` [PATCH -tip 1/3] x86/kprobes: Retrieve correct opcode for group instruction Masami Hiramatsu
2021-03-23 15:15           ` [tip: x86/core] " tip-bot2 for Masami Hiramatsu
2021-03-02 15:25         ` [PATCH -tip 2/3] x86/kprobes: Identify far indirect JMP correctly Masami Hiramatsu
2021-03-23 15:15           ` [tip: x86/core] " tip-bot2 for Masami Hiramatsu
2021-03-02 15:25         ` [PATCH -tip 3/3] x86/kprobes: Use int3 instead of debug trap for single-step Masami Hiramatsu
2021-03-23 15:15           ` [tip: x86/core] " tip-bot2 for Masami Hiramatsu
2021-03-17 14:55         ` [PATCH -tip 0/3] x86/kprobes: Remoev single-step trap from x86 kprobes Masami Hiramatsu
2021-03-17 16:26           ` Peter Zijlstra
2021-03-17 17:45             ` Andy Lutomirski
2021-02-25  9:59     ` Why do kprobes and uprobes singlestep? Peter Zijlstra
2021-03-01 16:51 ` Oleg Nesterov
2021-03-02  1:36   ` Andy Lutomirski
2021-03-02 20:24     ` Alexei Starovoitov
2021-03-02 21:02       ` Andy Lutomirski
2021-03-03  1:22         ` Alexei Starovoitov [this message]
2021-03-03  1:46           ` Andy Lutomirski
2021-03-03  2:18             ` Alexei Starovoitov
2021-03-03 13:27               ` Oleg Nesterov
2021-03-03 18:11               ` Daniel Xu
2021-03-03 19:14                 ` Andy Lutomirski
2021-03-02 20:25     ` Oleg Nesterov
2021-03-02 20:35       ` Andy Lutomirski
2021-03-02 20:28     ` Oleg Nesterov
2021-03-02  2:22   ` Masami Hiramatsu
2021-03-02  2:48     ` Andy Lutomirski
2021-03-02 20:31     ` Oleg Nesterov

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