From: Kyle Huey <me@kylehuey.com>
To: open list <linux-kernel@vger.kernel.org>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<x86@kernel.org>, Linus Torvalds <torvalds@linux-foundation.org>,
"Robert O'Callahan" <rocallahan@gmail.com>,
Alexandre Chartre <alexandre.chartre@oracle.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
Frederic Weisbecker <frederic@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Petr Mladek <pmladek@suse.com>,
Joel Fernandes <joel@joelfernandes.org>,
Steven Rostedt <rostedt@goodmis.org>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Juergen Gross <jgross@suse.com>, Brian Gerst <brgerst@gmail.com>,
Andy Lutomirski <luto@kernel.org>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Daniel Thompson <daniel.thompson@linaro.org>
Subject: [REGRESSION] x86/debug: After PTRACE_SINGLESTEP DR_STEP is no longer reported in dr6
Date: Mon, 26 Oct 2020 07:33:08 -0700 [thread overview]
Message-ID: <CAP045Ar5CtqknH66i5ti6xOvo9cC9ib5v-5+3fFKcp_DW91hYw@mail.gmail.com> (raw)
After resuming a ptracee with PTRACE_SINGLESTEP, in the following
ptrace stop retrieving the dr6 value for the tracee gets a value that
does not include DR_STEP (it is in fact always DR6_RESERVED). I
bisected this to the 13cb73490f475f8e7669f9288be0bcfa85399b1f merge. I
did not bisect further.
I don't see any handling to ever set DR_STEP in virtual_dr6, so I
think this code is just broken.
Sorry for not testing this when I was CCd on the original patch series :)
- Kyle
next reply other threads:[~2020-10-26 14:34 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-26 14:33 Kyle Huey [this message]
2020-10-26 15:55 ` [REGRESSION] x86/debug: After PTRACE_SINGLESTEP DR_STEP is no longer reported in dr6 Peter Zijlstra
2020-10-26 16:05 ` Peter Zijlstra
2020-10-26 16:14 ` Kyle Huey
2020-10-26 16:31 ` Peter Zijlstra
2020-10-26 16:55 ` Peter Zijlstra
2020-10-26 17:12 ` Kyle Huey
2020-10-26 17:17 ` Peter Zijlstra
2020-10-26 18:36 ` Kyle Huey
2020-10-26 23:30 ` Andy Lutomirski
2020-10-26 23:45 ` Andy Lutomirski
2020-10-27 8:15 ` Peter Zijlstra
2020-10-27 8:19 ` Peter Zijlstra
2020-10-27 18:00 ` Andy Lutomirski
2020-10-27 19:20 ` Peter Zijlstra
2020-10-27 9:08 ` Peter Zijlstra
2020-10-27 17:56 ` Peter Zijlstra
2020-10-26 16:08 ` Kyle Huey
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