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

From: priyalee . kushwaha
Date: Fri May 26 2017 - 11:20:44 EST


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