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Message-ID: <c029b85ad2c26ce37683d6e15406b7a90564ceb8.camel@linux.intel.com>
Subject: Re: [regression] Bug 217386 - intel_powerclamp null pointer
 dereference in Linux 6.3.x
From:   srinivas pandruvada <srinivas.pandruvada@linux.intel.com>
To:     "Rafael J. Wysocki" <rafael@kernel.org>,
        Linux regressions mailing list <regressions@lists.linux.dev>
Cc:     Daniel Lezcano <daniel.lezcano@linaro.org>,
        Linux PM <linux-pm@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
Date:   Wed, 03 May 2023 13:59:11 -0700
In-Reply-To: <CAJZ5v0hZXJYU6Maz39u2EyV=tqm-JZ9OErcByMD+=C8YgTKXpA@mail.gmail.com>
References: <0fd55257-5b26-1969-18b7-97b39c3f620b@leemhuis.info>
         <CAJZ5v0hZXJYU6Maz39u2EyV=tqm-JZ9OErcByMD+=C8YgTKXpA@mail.gmail.com>
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Hi All,

On Wed, 2023-05-03 at 14:34 +0200, Rafael J. Wysocki wrote:
> CC: Srinivas
> 
> On Tue, May 2, 2023 at 12:26 PM Linux regression tracking (Thorsten
> Leemhuis) <regressions@leemhuis.info> wrote:
> > 
> > 
> > Hi, Thorsten here, the Linux kernel's regression tracker.
> > 
> > I noticed a regression report in bugzilla.kernel.org. As many
> > (most?)
> > kernel developers don't keep an eye on it, I decided to forward it
> > by mail.
> > 
> > Note, you have to use bugzilla to reach the reporter, as I sadly[1]
> > can
> > not CCed them in mails like this.
> > 
> > Quoting from https://bugzilla.kernel.org/show_bug.cgi?id=217386 :
> > 

I have added the fix to
https://bugzilla.kernel.org/show_bug.cgi?id=217386

Please check.

Thanks,
Srinivas


> > >  Risto A. Paju 2023-05-01 09:49:03 UTC
> > > 
> > > Created attachment 304199 [details]
> > > dmesg-6.3.1
> > > 
> > > I use intel_powerclamp on a Thinkpad X220i via a custom script
> > > for
> > > thermal management, and it triggers a kernel bug in Linux 6.3.0
> > > and
> > > 6.3.1. The script has a part
> > > 
> > > awk something > /sys/class/thermal/cooling_device4/cur_state
> > > 
> > > and the awk process hangs, with the null pointer bug reported in
> > > dmesg.
> > > 
> > > The script has worked fine for years, and for now I've switched
> > > back to
> > > the 6.2 series for this laptop.
> > > 
> > > [tag] [reply] [−]
> > > Private
> > > Comment 1 Risto A. Paju 2023-05-01 12:23:15 UTC
> > > 
> > > The affected CPU is an i3-2310M. I tested the same on a newer
> > > Intel
> > > laptop with an i5-7300HQ, and there's no sign of the bug there.
> > 
> > From the dmesg:
> > 
> > > [   16.495596] Oops: 0002 [#1] PREEMPT SMP PTI
> > > [   16.496084] CPU: 0 PID: 2792 Comm: awk Not tainted 6.3.1 #2
> > > [   16.496589] Hardware name: LENOVO 428737G/428737G, BIOS
> > > 8DET76WW (1.46 ) 06/21/2018
> > > [   16.497095] RIP: 0010:idle_inject_set_duration+0x6/0x20
> > > [   16.497607] Code: 00 49 c7 c4 f4 ff ff ff eb 92 49 c7 c4 f4 ff
> > > ff ff eb 91 cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 89
> > > f0 01 d0 74 06 <89> 77 44 89 57 40 c3 cc cc cc cc 66 66 2e 0f 1f
> > > 84 00 00 00 00 00
> > > [   16.498824] RSP: 0018:ffffc900005e7de8 EFLAGS: 00010206
> > > [   16.499461] RAX: 00000000000927c0 RBX: 0000000000000000 RCX:
> > > 0000000000001770
> > > [   16.500103] RDX: 0000000000001770 RSI: 0000000000091050 RDI:
> > > 0000000000000000
> > > [   16.500752] RBP: 0000000000000002 R08: 0000000000000001 R09:
> > > 000000000000000a
> > > [   16.501405] R10: 000000000000000a R11: f000000000000000 R12:
> > > 0000000000000000
> > > [   16.502071] R13: ffff8881064bd720 R14: ffffc900005e7ea0 R15:
> > > ffff8881022283e0
> > > [   16.502745] FS:  00007fe494782b80(0000)
> > > GS:ffff888216200000(0000) knlGS:0000000000000000
> > > [   16.503421] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > > [   16.504095] CR2: 0000000000000044 CR3: 000000010f94c006 CR4:
> > > 00000000000606f0
> > > [   16.504783] Call Trace:
> > > [   16.505456]  <TASK>
> > > [   16.506124]  powerclamp_set_cur_state+0x56/0x200
> > > [intel_powerclamp]
> > > [   16.506810]  cur_state_store+0x74/0xd0
> > > [   16.507497]  kernfs_fop_write_iter+0x128/0x1c0
> > > [   16.508193]  vfs_write+0x2be/0x3f0
> > > [   16.508897]  ksys_write+0x5a/0xe0
> > > [   16.509794]  do_syscall_64+0x3b/0x90
> > > [   16.510607]  entry_SYSCALL_64_after_hwframe+0x72/0xdc
> > > [   16.511444] RIP: 0033:0x7fe4948c0be0
> > > [   16.512247] Code: 40 00 48 8b 15 49 c2 0d 00 f7 d8 64 89 02 48
> > > c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d 01 4a 0e 00 00 74 17 b8 01
> > > 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00
> > > 48 83 ec 28 48 89
> > > [   16.514025] RSP: 002b:00007ffc045bd0d8 EFLAGS: 00000202
> > > ORIG_RAX: 0000000000000001
> > > [   16.515180] RAX: ffffffffffffffda RBX: 0000000000000002 RCX:
> > > 00007fe4948c0be0
> > > [   16.516346] RDX: 0000000000000002 RSI: 0000562bc4d50990 RDI:
> > > 0000000000000001
> > > [   16.517543] RBP: 00007fe49499e780 R08: 0000000000000007 R09:
> > > 0000562bc4d46da0
> > > [   16.518751] R10: 00007fe4947d5f50 R11: 0000000000000202 R12:
> > > 0000000000000002
> > > [   16.519977] R13: 0000562bc4d50990 R14: 0000000000000002 R15:
> > > 00007fe494999d60
> > > [   16.521234]  </TASK>
> > > [   16.522479] Modules linked in:
> > > [...]
> > > [   16.534416] CR2: 0000000000000044
> > > [   16.536059] ---[ end trace 0000000000000000 ]---
> > > [   16.537819] RIP: 0010:idle_inject_set_duration+0x6/0x20
> > > [   16.537827] Code: 00 49 c7 c4 f4 ff ff ff eb 92 49 c7 c4 f4 ff
> > > ff ff eb 91 cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 89
> > > f0 01 d0 74 06 <89> 77 44 89 57 40 c3 cc cc cc cc 66 66 2e 0f 1f
> > > 84 00 00 00 00 00
> > > [   16.543180] RSP: 0018:ffffc900005e7de8 EFLAGS: 00010206
> > > [   16.543189] RAX: 00000000000927c0 RBX: 0000000000000000 RCX:
> > > 0000000000001770
> > > [   16.543193] RDX: 0000000000001770 RSI: 0000000000091050 RDI:
> > > 0000000000000000
> > > [   16.549435] RBP: 0000000000000002 R08: 0000000000000001 R09:
> > > 000000000000000a
> > > [   16.551087] R10: 000000000000000a R11: f000000000000000 R12:
> > > 0000000000000000
> > > [   16.551091] R13: ffff8881064bd720 R14: ffffc900005e7ea0 R15:
> > > ffff8881022283e0
> > > [   16.554264] FS:  00007fe494782b80(0000)
> > > GS:ffff888216200000(0000) knlGS:0000000000000000
> > > [   16.554270] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > > [   16.554281] CR2: 0000560363a98298 CR3: 000000010f94c006 CR4:
> > > 00000000000606f0
> > > [   17.635258] memfd_create() without MFD_EXEC nor
> > > MFD_NOEXEC_SEAL, pid=2842 'X'
> > 
> > 
> > See the ticket for more details.
> > 
> > 
> > [TLDR for the rest of this mail: I'm adding this report to the list
> > of
> > tracked Linux kernel regressions; the text you find below is based
> > on a
> > few templates paragraphs you might have encountered already in
> > similar
> > form.]
> > 
> > BTW, let me use this mail to also add the report to the list of
> > tracked
> > regressions to ensure it's doesn't fall through the cracks:
> > 
> > #regzbot introduced: v6.2..v6.3
> > https://bugzilla.kernel.org/show_bug.cgi?id=217386
> > #regzbot title: pm: thermal: intel_powerclamp null pointer
> > dereference
> > #regzbot ignore-activity
> > 
> > This isn't a regression? This issue or a fix for it are already
> > discussed somewhere else? It was fixed already? You want to clarify
> > when
> > the regression started to happen? Or point out I got the title or
> > something else totally wrong? Then just reply and tell me --
> > ideally
> > while also telling regzbot about it, as explained by the page
> > listed in
> > the footer of this mail.
> > 
> > Developers: When fixing the issue, remember to add 'Link:' tags
> > pointing
> > to the report (e.g. the buzgzilla ticket and maybe this mail as
> > well, if
> > this thread sees some discussion). See page linked in footer for
> > details.
> > 
> > Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker'
> > hat)
> > --
> > Everything you wanna know about Linux kernel regression tracking:
> > https://linux-regtracking.leemhuis.info/about/#tldr
> > If I did something stupid, please tell me, as explained on that
> > page.
> > 
> > [1] because bugzilla.kernel.org tells users upon registration their
> > "email address will never be displayed to logged out users"