From 0dc77b6dabec8fd298392018cc0de5214af2dc43 Mon Sep 17 00:00:00 2001 From: Peter Huewe Date: Mon, 24 Sep 2012 15:32:31 +0900 Subject: [PATCH] extcon: Unregister compat class at module unload to fix oops If you compile extcon with CONFIG_ANDROID and then load and unload the module you get a simple oops as the driver does not unregister its compat class and thus cannot register it again. Full trace: root@(none):~# modprobe extcon_class root@(none):~# rmmod extcon_class root@(none):~# modprobe extcon_class ------------[ cut here ]------------ WARNING: at fs/sysfs/dir.c:536 sysfs_add_one+0xde/0x100() sysfs: cannot create duplicate filename '/class/switch' Modules linked in: extcon_class(+) [last unloaded: extcon_class] Call Trace: 9f451a00: [<602a58bc>] printk+0x0/0xa8 9f451a18: [<60039b43>] warn_slowpath_common+0x93/0xd0 9f451a28: [<6012c6de>] sysfs_add_one+0xde/0x100 9f451a50: [<601d3d90>] strcat+0x0/0x40 9f451a68: [<60039cdc>] warn_slowpath_fmt+0x9c/0xa0 9f451a90: [<6002fe32>] unblock_signals+0x0/0x84 9f451ab0: [<60039c40>] warn_slowpath_fmt+0x0/0xa0 9f451ac0: [<6002fe32>] unblock_signals+0x0/0x84 9f451ae8: [<6012bd97>] sysfs_pathname.isra.10+0x57/0x70 9f451b00: [<601d3d90>] strcat+0x0/0x40 9f451b18: [<6012bd97>] sysfs_pathname.isra.10+0x57/0x70 9f451b48: [<6012c6de>] sysfs_add_one+0xde/0x100 9f451b78: [<6012c96f>] create_dir+0x8f/0x100 9f451bc0: [] extcon_class_init+0x0/0x12 [extcon_class] 9f451bd8: [<6012cda6>] sysfs_create_dir+0xa6/0x1c0 9f451be8: [<601d89f1>] kvasprintf+0x81/0xa0 9f451bf8: [<601cf0f0>] kobject_get+0x0/0x50 9f451c18: [<601cf396>] kobject_add_internal+0x96/0x280 9f451c60: [] extcon_class_init+0x0/0x12 [extcon_class] 9f451c78: [<601cfb93>] kobject_add+0xd3/0x140 9f451cc0: [<601cfac0>] kobject_add+0x0/0x140 9f451cd0: [<6002fe32>] unblock_signals+0x0/0x84 9f451cf8: [<6002fffc>] set_signals+0x29/0x3f 9f451d28: [<600c1de1>] kmem_cache_alloc+0xe1/0x100 9f451d78: [<601cffa0>] kobject_create_and_add+0x50/0xa0 9f451da8: [<601fbe76>] class_compat_register+0x56/0x80 9f451dc8: [] create_extcon_class+0x88/0xd0 [extcon_class] 9f451de8: [] extcon_class_init+0x10/0x12 [extcon_class] 9f451df8: [<600189a8>] do_one_initcall+0x48/0x1f0 9f451e20: [<60061920>] blocking_notifier_call_chain+0x0/0x20 9f451e30: [<60061920>] blocking_notifier_call_chain+0x0/0x20 9f451e58: [<6007e3c3>] sys_init_module+0xa3/0x280 9f451e88: [<6001e2ad>] handle_syscall+0x8d/0x90 9f451ea8: [<60033370>] userspace+0x405/0x531 9f451ee8: [<6001e380>] copy_chunk_to_user+0x0/0x40 9f451ef8: [<6001e5cd>] do_op_one_page+0x14d/0x220 9f451fd8: [<6001a355>] fork_handler+0x95/0xa0 ---[ end trace dd512cc03fe1c367 ]--- ------------[ cut here ]------------ WARNING: at lib/kobject.c:196 kobject_add_internal+0x26e/0x280() kobject_add_internal failed for switch with -EEXIST, don't try to register things with the same name in the same directory. Modules linked in: extcon_class(+) [last unloaded: extcon_class] Call Trace: 9f451ad0: [<602a58bc>] printk+0x0/0xa8 9f451ae8: [<60039b43>] warn_slowpath_common+0x93/0xd0 9f451af8: [<601cf56e>] kobject_add_internal+0x26e/0x280 9f451b18: [<601cf140>] kobject_put+0x0/0x70 9f451b20: [] extcon_class_init+0x0/0x12 [extcon_class] 9f451b38: [<60039cdc>] warn_slowpath_fmt+0x9c/0xa0 9f451b88: [<60039c40>] warn_slowpath_fmt+0x0/0xa0 9f451bc0: [] extcon_class_init+0x0/0x12 [extcon_class] 9f451bd8: [<6012cda6>] sysfs_create_dir+0xa6/0x1c0 9f451be8: [<601d89f1>] kvasprintf+0x81/0xa0 9f451bf8: [<601cf0f0>] kobject_get+0x0/0x50 9f451c18: [<601cf56e>] kobject_add_internal+0x26e/0x280 9f451c60: [] extcon_class_init+0x0/0x12 [extcon_class] 9f451c78: [<601cfb93>] kobject_add+0xd3/0x140 9f451cc0: [<601cfac0>] kobject_add+0x0/0x140 9f451cd0: [<6002fe32>] unblock_signals+0x0/0x84 9f451cf8: [<6002fffc>] set_signals+0x29/0x3f 9f451d28: [<600c1de1>] kmem_cache_alloc+0xe1/0x100 9f451d78: [<601cffa0>] kobject_create_and_add+0x50/0xa0 9f451da8: [<601fbe76>] class_compat_register+0x56/0x80 9f451dc8: [] create_extcon_class+0x88/0xd0 [extcon_class] 9f451de8: [] extcon_class_init+0x10/0x12 [extcon_class] 9f451df8: [<600189a8>] do_one_initcall+0x48/0x1f0 9f451e20: [<60061920>] blocking_notifier_call_chain+0x0/0x20 9f451e30: [<60061920>] blocking_notifier_call_chain+0x0/0x20 9f451e58: [<6007e3c3>] sys_init_module+0xa3/0x280 9f451e88: [<6001e2ad>] handle_syscall+0x8d/0x90 9f451ea8: [<60033370>] userspace+0x405/0x531 9f451ee8: [<6001e380>] copy_chunk_to_user+0x0/0x40 9f451ef8: [<6001e5cd>] do_op_one_page+0x14d/0x220 9f451fd8: [<6001a355>] fork_handler+0x95/0xa0 ---[ end trace dd512cc03fe1c368 ]--- kobject_create_and_add: kobject_add error: -17 ------------[ cut here ]------------ WARNING: at drivers/extcon/extcon_class.c:545 create_extcon_class+0xbc/0xd0 [extcon_class]() cannot allocate Modules linked in: extcon_class(+) [last unloaded: extcon_class] Call Trace: 9f451c80: [<602a58bc>] printk+0x0/0xa8 9f451c98: [<60039b43>] warn_slowpath_common+0x93/0xd0 9f451ca0: [<6002fe32>] unblock_signals+0x0/0x84 9f451ca8: [] create_extcon_class+0xbc/0xd0 [extcon_class] 9f451cd0: [] extcon_class_init+0x0/0x12 [extcon_class] 9f451ce8: [<60039cdc>] warn_slowpath_fmt+0x9c/0xa0 9f451d20: [<6002fe32>] unblock_signals+0x0/0x84 9f451d28: [<60039c40>] warn_slowpath_fmt+0x0/0xa0 9f451d48: [<6002fffc>] set_signals+0x29/0x3f 9f451d58: [<601cf172>] kobject_put+0x32/0x70 9f451d78: [<600c22c3>] kfree+0xb3/0x100 9f451da8: [<601fbe9a>] class_compat_register+0x7a/0x80 9f451dc8: [] create_extcon_class+0xbc/0xd0 [extcon_class] 9f451de8: [] extcon_class_init+0x10/0x12 [extcon_class] 9f451df8: [<600189a8>] do_one_initcall+0x48/0x1f0 9f451e20: [<60061920>] blocking_notifier_call_chain+0x0/0x20 9f451e30: [<60061920>] blocking_notifier_call_chain+0x0/0x20 9f451e58: [<6007e3c3>] sys_init_module+0xa3/0x280 9f451e88: [<6001e2ad>] handle_syscall+0x8d/0x90 9f451ea8: [<60033370>] userspace+0x405/0x531 9f451ee8: [<6001e380>] copy_chunk_to_user+0x0/0x40 9f451ef8: [<6001e5cd>] do_op_one_page+0x14d/0x220 9f451fd8: [<6001a355>] fork_handler+0x95/0xa0 ---[ end trace dd512cc03fe1c369 ]--- FATAL: Error inserting extcon_class (/lib/modules/3.6.0-rc6-00178-g811315f/kernel/drivers/extcon/extcon_class.ko): Cannot allocate memory This patch fixes this. Cc: stable@vger.kernel.org Signed-off-by: Peter Huewe Signed-off-by: Chanwoo Choi --- drivers/extcon/extcon-class.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c index 1ce76a8d777b..63715cdfe988 100644 --- a/drivers/extcon/extcon-class.c +++ b/drivers/extcon/extcon-class.c @@ -819,6 +819,9 @@ module_init(extcon_class_init); static void __exit extcon_class_exit(void) { +#if defined(CONFIG_ANDROID) + class_compat_unregister(switch_class); +#endif class_destroy(extcon_class); } module_exit(extcon_class_exit); -- 2.30.2