kgdbts: prevent re-entry to kgdbts before it unregisters
The "kgdb_connected" variable of debug_core just indicates whether or not kgdbts is connected to the debug_core. It does not completely prevent a script from trying invoke kgdbts again and possibly crashing the system (see Call Trace below). The configured variable in kgtbts can be used instead of kgdb_connected instead of kgdb_connected. The cleanup_kgdbts() can also be removed because there is no possible way to build kgdbts as a kernel module that you could unload with rmmod. Call Trace: ----------------------------------------------------------------- root:/$ echo kgdbts=V1S1000 > /sys/module/kgdbts/parameters/kgdbts kgdb: Unregistered I/O driver kgdbts, debugger disabled. ------------[ cut here ]------------ WARNING: at kernel/debug/debug_core.c:1002 kgdb_unregister_io_module+0xec/0x100() Hardware name: Moon Creek platform Modules linked in: Pid: 664, comm: sh Not tainted 2.6.34.1-WR4.0.0.0_standard #58 Call Trace: [<c103b1ed>] warn_slowpath_common+0x6d/0xa0 [<c1079fdc>] ? kgdb_unregister_io_module+0xec/0x100 [<c1079fdc>] ? kgdb_unregister_io_module+0xec/0x100 [<c10544e0>] ? param_attr_store+0x0/0x20 [<c103b235>] warn_slowpath_null+0x15/0x20 [<c1079fdc>] kgdb_unregister_io_module+0xec/0x100 [<c124e4ea>] cleanup_kgdbts+0x1a/0x20 [<c124eced>] param_set_kgdbts_var+0x6d/0xb0 [<c124ec80>] ? param_set_kgdbts_var+0x0/0xb0 [<c10544f7>] param_attr_store+0x17/0x20 [<c105457c>] module_attr_store+0x2c/0x40 [<c111fe84>] sysfs_write_file+0x94/0xf0 [<c10d42f6>] vfs_write+0x96/0x130 [<c111fdf0>] ? sysfs_write_file+0x0/0xf0 [<c10d44d6>] sys_write+0x46/0xd0 [<c13bf329>] system_call_done+0x0/0x4 ---[ end trace 4eb028c6ee43154c ]--- kgdb: Unregistered I/O driver kgdbts, debugger disabled. ----------------------------------------------------------------- [jason.wessel@windriver.com: remove cleanup_kgdbts() ] Signed-off-by: NDongdong Deng <dongdong.deng@windriver.com> Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Showing
想要评论请 注册 或 登录