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From:   Sasha Levin <Alexander.Levin@microsoft.com>
To:     "stable@vger.kernel.org" <stable@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
CC:     Priyalee Kushwaha <priyalee.kushwaha@intel.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Darren Hart <dvhart@infradead.org>,
        Sasha Levin <Alexander.Levin@microsoft.com>
Subject: [PATCH AUTOSEL for 4.9 060/293] platform/x86:
 intel_telemetry_debugfs: fix oops when load/unload module
Thread-Topic: [PATCH AUTOSEL for 4.9 060/293] platform/x86:
 intel_telemetry_debugfs: fix oops when load/unload module
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Date:   Mon, 9 Apr 2018 00:23:38 +0000
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From: Priyalee Kushwaha <priyalee.kushwaha@intel.com>

[ Upstream commit bf5d008164dd84d671ca2dd569a1676051f9faff ]

This fixes an oops found while testing load/unload of the
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 ffffffffa006f0=
10
 [ 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_ke=
ys dwc3 udc_core intel_telemetry_pltdrv intel_punit_ipc intel_telemetry_cor=
e rtc_cmos efivars x86_pkg_temp_thermal iwlwifi snd_hda_codec_hdmi soc_butt=
on_array btusb cfg80211 btrtl mei_me hci_uart btbcm mei btintel i915 blueto=
oth 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-d=
ev-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: 000000000000=
0000
 [ 97.604812] RDX: ffff880179eaf210 RSI: ffffffffa0131000 RDI: ffffffff81e3=
ea20
 [ 97.612821] RBP: ffff8801793f3c68 R08: 0000000000000006 R09: 000000000000=
005c
 [ 97.620847] R10: 0000000000000000 R11: 0000000000000006 R12: ffffffffa013=
1000
 [ 97.628855] R13: 0000000000000000 R14: ffff880176e35f48 R15: ffff8801793f=
3ea8
 [ 97.636865] FS: 00007f7eeba07700(0000) GS:ffff88017fc00000(0000) knlGS:00=
00000000000000
 [ 97.645948] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [ 97.652423] CR2: ffffffffa006f010 CR3: 00000001775ef000 CR4: 000000000034=
06f0
 [ 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@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 drivers/platform/x86/intel_telemetry_debugfs.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/platform/x86/intel_telemetry_debugfs.c b/drivers/platf=
orm/x86/intel_telemetry_debugfs.c
index ef29f18b1951..4cc2f4ea0a25 100644
--- a/drivers/platform/x86/intel_telemetry_debugfs.c
+++ b/drivers/platform/x86/intel_telemetry_debugfs.c
@@ -97,11 +97,9 @@
 	} \
 }
=20
-#ifdef CONFIG_PM_SLEEP
 static u8 suspend_prep_ok;
 static u32 suspend_shlw_ctr_temp, suspend_deep_ctr_temp;
 static u64 suspend_shlw_res_temp, suspend_deep_res_temp;
-#endif
=20
 struct telemetry_susp_stats {
 	u32 shlw_swake_ctr;
@@ -807,7 +805,6 @@ static const struct file_operations telem_ioss_trc_verb=
_ops =3D {
 	.release	=3D single_release,
 };
=20
-#ifdef CONFIG_PM_SLEEP
 static int pm_suspend_prep_cb(void)
 {
 	struct telemetry_evtlog evtlog[TELEM_MAX_OS_ALLOCATED_EVENTS];
@@ -937,7 +934,6 @@ static int pm_notification(struct notifier_block *this,
 static struct notifier_block pm_notifier =3D {
 	.notifier_call =3D pm_notification,
 };
-#endif /* CONFIG_PM_SLEEP */
=20
 static int __init telemetry_debugfs_init(void)
 {
@@ -960,14 +956,13 @@ static int __init telemetry_debugfs_init(void)
 	if (err < 0)
 		return -EINVAL;
=20
-
-#ifdef CONFIG_PM_SLEEP
 	register_pm_notifier(&pm_notifier);
-#endif /* CONFIG_PM_SLEEP */
=20
 	debugfs_conf->telemetry_dbg_dir =3D debugfs_create_dir("telemetry", NULL)=
;
-	if (!debugfs_conf->telemetry_dbg_dir)
-		return -ENOMEM;
+	if (!debugfs_conf->telemetry_dbg_dir) {
+		err =3D -ENOMEM;
+		goto out_pm;
+	}
=20
 	f =3D debugfs_create_file("pss_info", S_IFREG | S_IRUGO,
 				debugfs_conf->telemetry_dbg_dir, NULL,
@@ -1014,6 +1009,8 @@ static int __init telemetry_debugfs_init(void)
 out:
 	debugfs_remove_recursive(debugfs_conf->telemetry_dbg_dir);
 	debugfs_conf->telemetry_dbg_dir =3D NULL;
+out_pm:
+	unregister_pm_notifier(&pm_notifier);
=20
 	return err;
 }
@@ -1022,6 +1019,7 @@ static void __exit telemetry_debugfs_exit(void)
 {
 	debugfs_remove_recursive(debugfs_conf->telemetry_dbg_dir);
 	debugfs_conf->telemetry_dbg_dir =3D NULL;
+	unregister_pm_notifier(&pm_notifier);
 }
=20
 late_initcall(telemetry_debugfs_init);
--=20
2.15.1