Commits
Liu, Jinsong committed 1b2a05516e4
xen/mce: schedule a workqueue to avoid sleep in atomic context copy_to_user might sleep and print a stack trace if it is executed in an atomic spinlock context. Like this: (XEN) CMCI: send CMCI to DOM0 through virq BUG: sleeping function called from invalid context at /home/konradinux/kernel.h:199 in_atomic(): 1, irqs_disabled(): 0, pid: 4581, name: mcelog Pid: 4581, comm: mcelog Tainted: G O 3.5.0-rc1upstream-00003-g149000b-dirty #1 [<ffffffff8109ad9a>] __might_sleep+0xda/0x100 [<ffffffff81329b0b>] xen_mce_chrdev_read+0xab/0x140 [<ffffffff81148945>] vfs_read+0xc5/0x190 [<ffffffff81148b0c>] sys_read+0x4c/0x90 [<ffffffff815bd039>] system_call_fastpath+0x16 This patch schedule a workqueue for IRQ handler to poll the data, and use mutex instead of spinlock, so copy_to_user sleep in atomic context would not occur. Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Suggested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>