Re: linux-next boot error: WARNING in corrupted

[Viresh Kumar]

On 05-07-19, 11:37, Dmitry Vyukov wrote:
> On Fri, Jul 5, 2019 at 11:23 AM Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote:
> >
> > On Thursday, July 4, 2019 7:27:04 PM CEST syzbot wrote:
> > > Hello,
> > >
> > > syzbot found the following crash on:
> > >
> > > HEAD commit:    16c474c9 Add linux-next specific files for 20190704
> > > git tree:       linux-next
> > > console output: https://syzkaller.appspot.com/x/log.txt?x=17f8b463a00000
> > > kernel config:  https://syzkaller.appspot.com/x/.config?x=983f02aae1ef31b6
> > > dashboard link: https://syzkaller.appspot.com/bug?extid=de771ae9390dffed7266
> > > compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> > >
> > > Unfortunately, I don't have any reproducer for this crash yet.
> > >
> > > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > > Reported-by: syzbot+de771ae9390dffed7266@xxxxxxxxxxxxxxxxxxxxxxxxx
> > >
> ...
> > > ------------[ cut here ]------------
> > > __dev_pm_qos_remove_request() called for unknown object
> > > WARNING: CPU: 1 PID: 1 at drivers/base/power/qos.c:486
> > > __dev_pm_qos_remove_request+0x3d3/0x4d0 drivers/base/power/qos.c:486
> >
> > Viresh, any chance to look at this?
> >
> > I'm a bit concerned about the freq QoS series at this point, may defer pushing it.
> 
> FWIW here is full WARNING since I am hitting it locally too:
> 
> commit 16c474c9ba39ede5fd1cd835ac52b3760d7820b7 (HEAD, tag:
> next-20190704, next/master)
>     Add linux-next specific files for 20190704
> 
> ------------[ cut here ]------------
> __dev_pm_qos_remove_request() called for unknown object
> WARNING: CPU: 3 PID: 1 at drivers/base/power/qos.c:486
> __dev_pm_qos_remove_reques0
> Kernel panic - not syncing: panic_on_warn set ...
> CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc7-next-20190704 #2
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
> Call Trace:
>  __dump_stack lib/dump_stack.c:77 [inline]
>  dump_stack+0x172/0x1f0 lib/dump_stack.c:113
>  panic+0x2dc/0x755 kernel/panic.c:219
>  __warn.cold+0x20/0x4c kernel/panic.c:576
>  report_bug+0x263/0x2b0 lib/bug.c:186
>  fixup_bug arch/x86/kernel/traps.c:179 [inline]
>  fixup_bug arch/x86/kernel/traps.c:174 [inline]
>  do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272
>  do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291
>  invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1008
> RIP: 0010:__dev_pm_qos_remove_request+0x3d3/0x4d0 drivers/base/power/qos.c:486
> Code: 09 fd e9 9a fd ff ff 41 bd ed ff ff ff e9 b8 fd ff ff e8 d0 c9
> 7b fd 48 c7 2
> RSP: 0000:ffff88806c27fac8 EFLAGS: 00010282
> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: ffffffff815cae36 RDI: ffffed100d84ff4b
> RBP: ffff88806c27faf8 R08: ffff88806c276000 R09: fffffbfff14a6b45
> R10: fffffbfff14a6b44 R11: ffffffff8a535a27 R12: ffff8880664cf0f8
> R13: ffff88806ae4c000 R14: 0000000000000004 R15: ffff88806ae4c008
>  dev_pm_qos_remove_request+0x24/0x40 drivers/base/power/qos.c:520
>  cpufreq_policy_free+0x2b7/0x3d0 drivers/cpufreq/cpufreq.c:1282
>  cpufreq_online+0x239/0x17a0 drivers/cpufreq/cpufreq.c:1482
>  cpufreq_add_dev+0x119/0x160 drivers/cpufreq/cpufreq.c:1500
>  subsys_interface_register+0x2fc/0x470 drivers/base/bus.c:1081
>  cpufreq_register_driver+0x331/0x570 drivers/cpufreq/cpufreq.c:2669
>  acpi_cpufreq_init+0x579/0x5ff drivers/cpufreq/acpi-cpufreq.c:966
>  do_one_initcall+0x120/0x81a init/main.c:939
>  do_initcall_level init/main.c:1007 [inline]
>  do_initcalls init/main.c:1015 [inline]
>  do_basic_setup init/main.c:1033 [inline]
>  kernel_init_freeable+0x4d4/0x5c3 init/main.c:1193
>  kernel_init+0x12/0x1c5 init/main.c:1111
>  ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
> Kernel Offset: disabled
> Rebooting in 86400 seconds..

This fixes it for me (after faking the failure). @Rafael this needs to
be merged to the top commit:

0d4c2a013b32 cpufreq: Add QoS requests for userspace constraints

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 13c2f119cc0c..5eecd54195a9 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1228,12 +1228,6 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
                goto err_min_qos_notifier;
        }
 
-       policy->min_freq_req = kzalloc(2 * sizeof(*policy->min_freq_req),
-                                      GFP_KERNEL);
-       if (!policy->min_freq_req)
-               goto err_max_qos_notifier;
-
-       policy->max_freq_req = policy->min_freq_req + 1;
        INIT_LIST_HEAD(&policy->policy_list);
        init_rwsem(&policy->rwsem);
        spin_lock_init(&policy->transition_lock);
@@ -1244,9 +1238,6 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
        policy->cpu = cpu;
        return policy;
 
-err_max_qos_notifier:
-       dev_pm_qos_remove_notifier(dev, &policy->nb_max,
-                                  DEV_PM_QOS_MAX_FREQUENCY);
 err_min_qos_notifier:
        dev_pm_qos_remove_notifier(dev, &policy->nb_min,
                                   DEV_PM_QOS_MIN_FREQUENCY);
@@ -1370,6 +1361,13 @@ static int cpufreq_online(unsigned int cpu)
                        add_cpu_dev_symlink(policy, j);
                }
 
+               policy->min_freq_req = kzalloc(2 * sizeof(*policy->min_freq_req),
+                                              GFP_KERNEL);
+               if (!policy->min_freq_req)
+                       goto out_destroy_policy;
+
+               policy->max_freq_req = policy->min_freq_req + 1;
+
                ret = dev_pm_qos_add_request(dev, policy->min_freq_req,
                                             DEV_PM_QOS_MIN_FREQUENCY,
                                             policy->min);


-- 
viresh