From: Peter Zijlstra <peterz@infradead.org>
To: Nikolay Borisov <nborisov@suse.com>
Cc: Masami Hiramatsu <masami.hiramatsu@gmail.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
bpf@vger.kernel.org, Josh Poimboeuf <jpoimboe@redhat.com>,
Steven Rostedt <rostedt@goodmis.org>
Subject: Re: kprobes broken since 0d00449c7a28 ("x86: Replace ist_enter() with nmi_enter()")
Date: Thu, 28 Jan 2021 19:24:14 +0100 [thread overview]
Message-ID: <YBMBTsY1uuQb9wCP@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <eb1ec6a3-9e11-c769-84a4-228f23dc5e23@suse.com>
On Thu, Jan 28, 2021 at 06:45:56PM +0200, Nikolay Borisov wrote:
> it would be placed on the __fentry__ (and not endbr64) hence it works.
> So perhaps a workaround outside of bpf could essentially detect this
> scenario and adjust the probe to be on the __fentry__ and not preceding
> instruction if it's detected to be endbr64 ?
Arguably the fentry handler should also set the nmi context, it can,
after all, interrupt pretty much any other context by construction.
next prev parent reply other threads:[~2021-01-28 18:27 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <25cd2608-03c2-94b8-7760-9de9935fde64@suse.com>
[not found] ` <20210128001353.66e7171b395473ef992d6991@kernel.org>
[not found] ` <20210128002452.a79714c236b69ab9acfa986c@kernel.org>
[not found] ` <a35a6f15-9ab1-917c-d443-23d3e78f2d73@suse.com>
[not found] ` <20210128103415.d90be51ec607bb6123b2843c@kernel.org>
2021-01-28 3:38 ` kprobes broken since 0d00449c7a28 ("x86: Replace ist_enter() with nmi_enter()") Masami Hiramatsu
2021-01-28 7:11 ` Nikolay Borisov
2021-01-28 16:12 ` Nikolay Borisov
2021-01-28 16:45 ` Nikolay Borisov
2021-01-28 16:50 ` Josh Poimboeuf
2021-01-28 21:52 ` [PATCH] x86: Disable CET instrumentation in the kernel Josh Poimboeuf
2021-01-29 6:23 ` Nikolay Borisov
2021-01-29 10:21 ` Borislav Petkov
[not found] ` <20210129151034.iba4eaa2fuxsipqa@treble>
2021-01-29 16:30 ` Borislav Petkov
2021-01-29 16:49 ` Josh Poimboeuf
2021-01-29 16:54 ` Nikolay Borisov
2021-01-29 17:03 ` Josh Poimboeuf
2021-01-29 17:07 ` Borislav Petkov
2021-01-29 17:58 ` Seth Forshee
2021-01-28 18:24 ` Peter Zijlstra [this message]
2021-01-29 1:34 ` kprobes broken since 0d00449c7a28 ("x86: Replace ist_enter() with nmi_enter()") Alexei Starovoitov
2021-01-29 6:36 ` Nikolay Borisov
[not found] ` <YBPNyRyrkzw2echi@hirez.programming.kicks-ass.net>
[not found] ` <20210129224011.81bcdb3eba1227c414e69e1f@kernel.org>
[not found] ` <20210129105952.74dc8464@gandalf.local.home>
2021-01-29 16:24 ` Peter Zijlstra
2021-01-29 17:45 ` Alexei Starovoitov
2021-01-29 17:59 ` Peter Zijlstra
2021-01-29 19:01 ` Steven Rostedt
2021-01-29 21:05 ` Alexei Starovoitov
2021-01-30 1:41 ` Masami Hiramatsu
2021-01-29 21:24 ` Steven Rostedt
2021-01-30 8:28 ` Peter Zijlstra
2021-01-30 12:44 ` Steven Rostedt
2021-02-02 10:45 ` Peter Zijlstra
2021-02-02 14:52 ` Steven Rostedt
2021-02-02 16:45 ` Peter Zijlstra
2021-02-02 16:56 ` Steven Rostedt
2021-02-02 18:30 ` Peter Zijlstra
2021-02-02 21:05 ` Steven Rostedt
2021-02-03 13:33 ` Masami Hiramatsu
2021-02-03 13:52 ` Steven Rostedt
2021-01-30 2:02 ` Masami Hiramatsu
2021-01-30 3:08 ` Alexei Starovoitov
2021-01-30 12:10 ` Masami Hiramatsu
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