RE: [PATCH v1 1/1] intel_telemetry_debugfs: fix oops found while load/unload module test

[Chakravarty, Souvik K]

Thanks for catching this.

BR,
Souvik

> -----Original Message-----
> From: platform-driver-x86-owner@xxxxxxxxxxxxxxx [mailto:platform-driver-
> x86-owner@xxxxxxxxxxxxxxx] On Behalf Of priyalee.kushwaha@xxxxxxxxx
> Sent: Saturday, May 27, 2017 8:48 PM
> To: dvhart@xxxxxxxxxxxxx; Chakravarty, Souvik K
> <souvik.k.chakravarty@xxxxxxxxx>; andy@xxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx; platform-driver-x86@xxxxxxxxxxxxxxx;
> Kushwaha, Priyalee <priyalee.kushwaha@xxxxxxxxx>
> Subject: [PATCH v1 1/1] intel_telemetry_debugfs: fix oops found while
> load/unload module test
> 
> From: Priyalee Kushwaha <priyalee.kushwaha@xxxxxxxxx>
> 
> This fix oops found while testing load/unload test of
> intel_telemetry_debugfs module. Module_init uses register_pm_notifier
> for PM callbacks, but unregister_pm_notifier was missing from
> module_exit.
> 
>  [ 97.481860] BUG: unable to handle kernel paging request at
> ffffffffa006f010  [ 97.489742] IP:
> blocking_notifier_chain_register+0x3a/0xa0
>  [ 97.495898] PGD 2e0a067
>  [ 97.495899] PUD 2e0b063
>  [ 97.498737] PMD 179e29067
>  [ 97.501573] PTE 0
> 
>  [ 97.508423] Oops: 0000 1 PREEMPT SMP
>  [ 97.512724] Modules linked in: intel_telemetry_debugfs intel_rapl
> gpio_keys dwc3 udc_core intel_telemetry_pltdrv intel_punit_ipc
> intel_telemetry_core rtc_cmos efivars x86_pkg_temp_thermal iwlwifi
> snd_hda_codec_hdmi soc_button_array btusb cfg80211 btrtl mei_me
> hci_uart btbcm mei btintel i915 bluetooth intel_pmc_ipc snd_hda_intel
> spi_pxa2xx_platform snd_hda_codec dwc3_pci snd_hda_core tpm_tis
> tpm_tis_core tpm efivarfs  [ 97.558453] CPU: 0 PID: 889 Comm: modprobe
> Not tainted 4.11.0-rc6-intel-dev-bkc #1  [ 97.566950] Hardware name: Intel
> Corp. Joule DVT3/SDS, BIOS GTPP181A.X64.0143.B30.1701132137
> 01/13/2017  [ 97.577518] task: ffff8801793a21c0 task.stack:
> ffff8801793f0000  [ 97.584162] RIP:
> 0010:blocking_notifier_chain_register+0x3a/0xa0
>  [ 97.590903] RSP: 0018:ffff8801793f3c58 EFLAGS: 00010286  [
> 97.596802] RAX: ffffffffa006f000 RBX: ffffffff81e3ea20 RCX:
> 0000000000000000  [ 97.604812] RDX: ffff880179eaf210 RSI:
> ffffffffa0131000 RDI: ffffffff81e3ea20  [ 97.612821] RBP: ffff8801793f3c68
> R08: 0000000000000006 R09: 000000000000005c  [ 97.620847] R10:
> 0000000000000000 R11: 0000000000000006 R12: ffffffffa0131000  [
> 97.628855] R13: 0000000000000000 R14: ffff880176e35f48 R15:
> ffff8801793f3ea8  [ 97.636865] FS: 00007f7eeba07700(0000)
> GS:ffff88017fc00000(0000) knlGS:0000000000000000  [ 97.645948] CS:
> 0010 DS: 0000 ES: 0000 CR0: 0000000080050033  [ 97.652423] CR2:
> ffffffffa006f010 CR3: 00000001775ef000 CR4: 00000000003406f0  [
> 97.660423] Call Trace:
>  [ 97.663166] ? 0xffffffffa0031000
>  [ 97.666885] register_pm_notifier+0x18/0x20  [ 97.671581]
> telemetry_debugfs_init+0x92/0x1000
> 
> Signed-off-by: Priyalee Kushwaha <priyalee.kushwaha@xxxxxxxxx>
> ---
>  drivers/platform/x86/intel_telemetry_debugfs.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/platform/x86/intel_telemetry_debugfs.c
> b/drivers/platform/x86/intel_telemetry_debugfs.c
> index ef29f18..0f93975 100644
> --- a/drivers/platform/x86/intel_telemetry_debugfs.c
> +++ b/drivers/platform/x86/intel_telemetry_debugfs.c
> @@ -966,8 +966,12 @@ static int __init telemetry_debugfs_init(void)
> #endif /* CONFIG_PM_SLEEP */
> 
>  	debugfs_conf->telemetry_dbg_dir =
> debugfs_create_dir("telemetry", NULL);
> -	if (!debugfs_conf->telemetry_dbg_dir)
> +	if (!debugfs_conf->telemetry_dbg_dir) { #ifdef CONFIG_PM_SLEEP
> +		unregister_pm_notifier(&pm_notifier);
> +#endif /* CONFIG_PM_SLEEP */
>  		return -ENOMEM;
> +	}
> 
>  	f = debugfs_create_file("pss_info", S_IFREG | S_IRUGO,
>  				debugfs_conf->telemetry_dbg_dir, NULL,
> @@ -1014,6 +1018,9 @@ static int __init telemetry_debugfs_init(void)
>  out:
>  	debugfs_remove_recursive(debugfs_conf->telemetry_dbg_dir);
>  	debugfs_conf->telemetry_dbg_dir = NULL;
> +#ifdef CONFIG_PM_SLEEP
> +	unregister_pm_notifier(&pm_notifier);
> +#endif /* CONFIG_PM_SLEEP */
> 
>  	return err;
>  }
> @@ -1022,6 +1029,9 @@ static void __exit telemetry_debugfs_exit(void)
> {
>  	debugfs_remove_recursive(debugfs_conf->telemetry_dbg_dir);
>  	debugfs_conf->telemetry_dbg_dir = NULL;
> +#ifdef CONFIG_PM_SLEEP
> +	unregister_pm_notifier(&pm_notifier);
> +#endif /* CONFIG_PM_SLEEP */
>  }
> 
>  late_initcall(telemetry_debugfs_init);
> --
> 2.10.0