Re: BUG: using __this_cpu_read() in preemptible code in trace_hardirqs_on

2020-10-23 Thread Peter Zijlstra
On Thu, Oct 22, 2020 at 04:32:47PM -0400, Steven Rostedt wrote: > On Thu, 22 Oct 2020 12:30:28 +0200 > Peter Zijlstra wrote: > > > Subject: lockdep: Fix preemption WARN for spurious IRQ-enable > > From: Peter Zijlstra > > Date: Thu Oct 22 12:23:02 CEST 2020 > > > > It is valid (albeit uncommon)

Re: BUG: using __this_cpu_read() in preemptible code in trace_hardirqs_on

2020-10-22 Thread Steven Rostedt
On Thu, 22 Oct 2020 12:30:28 +0200 Peter Zijlstra wrote: > Subject: lockdep: Fix preemption WARN for spurious IRQ-enable > From: Peter Zijlstra > Date: Thu Oct 22 12:23:02 CEST 2020 > > It is valid (albeit uncommon) to call local_irq_enable() without first > having called local_irq_disable(). I

Re: BUG: using __this_cpu_read() in preemptible code in trace_hardirqs_on

2020-10-22 Thread Peter Zijlstra
On Wed, Oct 21, 2020 at 11:27:57AM -0400, Steven Rostedt wrote: > On Wed, 21 Oct 2020 17:12:37 +0200 > Peter Zijlstra wrote: > > > > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > > > > index 3e99dfef8408..9f818145ef7d 100644 > > > > --- a/kernel/locking/lockdep.c > > > > ++

Re: BUG: using __this_cpu_read() in preemptible code in trace_hardirqs_on

2020-10-21 Thread Steven Rostedt
On Wed, 21 Oct 2020 17:12:37 +0200 Peter Zijlstra wrote: > > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > > > index 3e99dfef8408..9f818145ef7d 100644 > > > --- a/kernel/locking/lockdep.c > > > +++ b/kernel/locking/lockdep.c > > > @@ -4057,9 +4057,6 @@ void lockdep_hardirqs

Re: BUG: using __this_cpu_read() in preemptible code in trace_hardirqs_on

2020-10-21 Thread Peter Zijlstra
On Wed, Oct 21, 2020 at 10:34:33AM -0400, Steven Rostedt wrote: > On Wed, 21 Oct 2020 15:17:33 +0200 > Peter Zijlstra wrote: > > > > And I'm also guessing that we can call this with interrupts enabled (based > > > on the comment). > > > > > > And we have this: > > > > > >local_irq_enable()

Re: BUG: using __this_cpu_read() in preemptible code in trace_hardirqs_on

2020-10-21 Thread Steven Rostedt
On Wed, 21 Oct 2020 15:17:33 +0200 Peter Zijlstra wrote: > > And I'm also guessing that we can call this with interrupts enabled (based > > on the comment). > > > > And we have this: > > > >local_irq_enable() > > trace_hardirqs_on() > > lockdep_hardirqs_on() > >

Re: BUG: using __this_cpu_read() in preemptible code in trace_hardirqs_on

2020-10-21 Thread Peter Zijlstra
On Tue, Oct 13, 2020 at 09:17:43AM -0400, Steven Rostedt wrote: > On Tue, 13 Oct 2020 04:22:21 -0700 > syzbot wrote: > > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit:865c50e1 x86/uaccess: utilize CONFIG_CC_HAS_ASM_GOTO_OUTPUT > > git tree: upstream > > con

Re: BUG: using __this_cpu_read() in preemptible code in trace_hardirqs_on

2020-10-21 Thread Dmitry Vyukov
On Fri, Oct 16, 2020 at 10:33 PM syzbot wrote: > > syzbot has bisected this issue to: > > commit 4d004099a668c41522242aa146a38cc4eb59cb1e > Author: Peter Zijlstra > Date: Fri Oct 2 09:04:21 2020 + > > lockdep: Fix lockdep recursion > > bisection log: https://syzkaller.appspot.com/x/bis

Re: BUG: using __this_cpu_read() in preemptible code in trace_hardirqs_on

2020-10-16 Thread syzbot
syzbot has bisected this issue to: commit 4d004099a668c41522242aa146a38cc4eb59cb1e Author: Peter Zijlstra Date: Fri Oct 2 09:04:21 2020 + lockdep: Fix lockdep recursion bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=174a766f90 start commit: 9ff9b0d3 Merge tag 'net-

Re: BUG: using __this_cpu_read() in preemptible code in trace_hardirqs_on

2020-10-16 Thread syzbot
syzbot has found a reproducer for the following issue on: HEAD commit:9ff9b0d3 Merge tag 'net-next-5.10' of git://git.kernel.org.. git tree: net-next console output: https://syzkaller.appspot.com/x/log.txt?x=1663860790 kernel config: https://syzkaller.appspot.com/x/.config?x=d13c3fa

Re: BUG: using __this_cpu_read() in preemptible code in trace_hardirqs_on

2020-10-13 Thread Steven Rostedt
On Tue, 13 Oct 2020 04:22:21 -0700 syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit:865c50e1 x86/uaccess: utilize CONFIG_CC_HAS_ASM_GOTO_OUTPUT > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=15112ef050 > kernel confi

BUG: using __this_cpu_read() in preemptible code in trace_hardirqs_on

2020-10-13 Thread syzbot
Hello, syzbot found the following issue on: HEAD commit:865c50e1 x86/uaccess: utilize CONFIG_CC_HAS_ASM_GOTO_OUTPUT git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15112ef050 kernel config: https://syzkaller.appspot.com/x/.config?x=c829313274207568 dash