Re: [tip:x86/urgent] x86/mce: Fix CMCI preemption bugs

2014-04-25 Thread Ingo Molnar
* Chen, Gong wrote: > On Fri, Apr 18, 2014 at 10:07:16AM +0200, Ingo Molnar wrote: > > Okay, so AFAICS the fix in x86/urgent isn't wrong functionally, it's > > just that the changelog incorrectly claims the raw-spinlock use is a > > bug causing a problem here. > > > > Still that raw spinlock

Re: [tip:x86/urgent] x86/mce: Fix CMCI preemption bugs

2014-04-25 Thread Chen, Gong
On Fri, Apr 18, 2014 at 10:07:16AM +0200, Ingo Molnar wrote: > Okay, so AFAICS the fix in x86/urgent isn't wrong functionally, it's > just that the changelog incorrectly claims the raw-spinlock use is a > bug causing a problem here. > > Still that raw spinlock is bogus and might be hiding other

Re: [tip:x86/urgent] x86/mce: Fix CMCI preemption bugs

2014-04-18 Thread Borislav Petkov
On Fri, Apr 18, 2014 at 10:07:16AM +0200, Ingo Molnar wrote: > Okay, so AFAICS the fix in x86/urgent isn't wrong functionally, it's > just that the changelog incorrectly claims the raw-spinlock use is a > bug causing a problem here. > > Still that raw spinlock is bogus and might be hiding other pro

Re: [tip:x86/urgent] x86/mce: Fix CMCI preemption bugs

2014-04-18 Thread Ingo Molnar
* Borislav Petkov wrote: > On Thu, Apr 17, 2014 at 11:30:12PM +0200, Borislav Petkov wrote: > > This is most likely unrelated and is caused by the preemption checks > > added to __this_cpu_* in 188a81409ff7. If you'd like to debug this > > further, please send a full dmesg: > > > > dmesg > dmes

Re: [tip:x86/urgent] x86/mce: Fix CMCI preemption bugs

2014-04-17 Thread Borislav Petkov
On Thu, Apr 17, 2014 at 11:30:12PM +0200, Borislav Petkov wrote: > This is most likely unrelated and is caused by the preemption checks > added to __this_cpu_* in 188a81409ff7. If you'd like to debug this > further, please send a full dmesg: > > dmesg > dmesg.log > > Privately is fine too. Ok, t

Re: [tip:x86/urgent] x86/mce: Fix CMCI preemption bugs

2014-04-17 Thread Borislav Petkov
On Thu, Apr 17, 2014 at 02:21:41PM -0700, Owen Kibel wrote: > The patch tested was from Chen, Gong > > https://lkml.org/lkml/2014/4/15/838 > > It worked, apart from the warning on boot described previously - the > possible boot message was extracted from /var/log/kern.log > > The above patch on

Re: [tip:x86/urgent] x86/mce: Fix CMCI preemption bugs

2014-04-17 Thread Borislav Petkov
On Thu, Apr 17, 2014 at 09:42:41PM +0200, Borislav Petkov wrote: > On Thu, Apr 17, 2014 at 12:25:14PM -0700, Linus Torvalds wrote: > > No, Owen tested a simpler patch that just changes the "get_cpu_var()" > > to "__get_cpu_var()" and avoids the preempt increment. > > Which basically would be the s

Re: [tip:x86/urgent] x86/mce: Fix CMCI preemption bugs

2014-04-17 Thread Borislav Petkov
On Thu, Apr 17, 2014 at 12:25:14PM -0700, Linus Torvalds wrote: > No, Owen tested a simpler patch that just changes the "get_cpu_var()" > to "__get_cpu_var()" and avoids the preempt increment. Which basically would be the same as doing this_cpu_write() in the proposed fix - both don't touch preemp

Re: [tip:x86/urgent] x86/mce: Fix CMCI preemption bugs

2014-04-17 Thread Linus Torvalds
On Thu, Apr 17, 2014 at 12:23 PM, Borislav Petkov wrote: > > But you're saying here, Owen tested it already. No, Owen tested a simpler patch that just changes the "get_cpu_var()" to "__get_cpu_var()" and avoids the preempt increment. Linus -- To unsubscribe from this list: send the

Re: [tip:x86/urgent] x86/mce: Fix CMCI preemption bugs

2014-04-17 Thread Borislav Petkov
On Thu, Apr 17, 2014 at 12:54:21PM -0400, Josh Boyer wrote: > A user (Owen) reported seeing the following backtrace with 3.15-rc1+: > > kernel: [ 120.253539] Hardware name: Hewlett-Packard HP ENVY 15 > Notebook PC/1962, BIOS F.24 08/27/2013 > kernel: [ 120.253540] 88025f2146c0 81c01

Re: [tip:x86/urgent] x86/mce: Fix CMCI preemption bugs

2014-04-17 Thread Josh Boyer
On Thu, Apr 17, 2014 at 11:26 AM, Borislav Petkov wrote: > On Thu, Apr 17, 2014 at 02:03:34PM +, Luck, Tony wrote: >> > Hohum, __raw_spin_lock_irqsave does preempt_disable(). And >> > machine_check_poll should be running in irq context so why would the >> > original issue happen? >> > >> >> ke

Re: [tip:x86/urgent] x86/mce: Fix CMCI preemption bugs

2014-04-17 Thread Borislav Petkov
On Thu, Apr 17, 2014 at 02:03:34PM +, Luck, Tony wrote: > > Hohum, __raw_spin_lock_irqsave does preempt_disable(). And > > machine_check_poll should be running in irq context so why would the > > original issue happen? > > > >> kernel: [7.341085] BUG: using __this_cpu_write() in preemptible

RE: [tip:x86/urgent] x86/mce: Fix CMCI preemption bugs

2014-04-17 Thread Luck, Tony
> Hohum, __raw_spin_lock_irqsave does preempt_disable(). And > machine_check_poll should be running in irq context so why would the > original issue happen? > >> kernel: [7.341085] BUG: using __this_cpu_write() in preemptible >> [] code: modprobe/546 > > Unfortunately, I have only one

Re: [tip:x86/urgent] x86/mce: Fix CMCI preemption bugs

2014-04-17 Thread Borislav Petkov
On Thu, Apr 17, 2014 at 12:09:44PM +0200, Peter Zijlstra wrote: > On Thu, Apr 17, 2014 at 02:57:54AM -0700, tip-bot for Ingo Molnar wrote: > > Commit-ID: ea431643d6c38728195e2c456801c3ef66bb9991 > > Gitweb: > > http://git.kernel.org/tip/ea431643d6c38728195e2c456801c3ef66bb9991 > > Author:

Re: [tip:x86/urgent] x86/mce: Fix CMCI preemption bugs

2014-04-17 Thread Peter Zijlstra
On Thu, Apr 17, 2014 at 02:57:54AM -0700, tip-bot for Ingo Molnar wrote: > Commit-ID: ea431643d6c38728195e2c456801c3ef66bb9991 > Gitweb: http://git.kernel.org/tip/ea431643d6c38728195e2c456801c3ef66bb9991 > Author: Ingo Molnar > AuthorDate: Thu, 17 Apr 2014 10:25:53 +0200 > Committer: Ing