On 2018/12/20 10:16, Vineet Gupta wrote: > On 12/19/18 9:04 AM, Eugeniy Paltsev wrote: >> As I can see x86 use print_vma_addr() in their show_signal_msg() >> function which allocate page with __get_free_page(GFP_NOWAIT); > > Indeed with that the __get_free_page() lockdep splat is gone. > > There's a different one now hence my other patch. > > | [ARCLinux]# ./segv-null-ptr > | potentially unexpected fatal signal 11. > | BUG: sleeping function called from invalid context at kernel/fork.c:1011 > | in_atomic(): 1, irqs_disabled(): 0, pid: 70, name: segv-null-ptr > | no locks held by segv-null-ptr/70. > | CPU: 0 PID: 70 Comm: segv-null-ptr Not tainted 4.18.0+ #69 > | > | Stack Trace: > | arc_unwind_core+0xcc/0x100 > | ___might_sleep+0x17a/0x190 > | mmput+0x16/0xb8 Then, does mmput_async() help? > | show_regs+0x52/0x310 > | get_signal+0x5ee/0x610 > | do_signal+0x2c/0x218 > | resume_user_mode_begin+0x90/0xd8
