Subject: linux-next: manual merge of the userns tree with the tip tree

From: Stephen Rothwell <[email-masked]>
Date: Mon, 24 Sep 2018 13:34:34 +1000

Hi Eric,

Today's linux-next merge of the userns tree got a conflict in:

  arch/x86/kernel/traps.c

between commits:

  76dee4a72849 ("x86/kprobes: Inline kprobe_exceptions_notify() into do_general_protection()")
  81fd9c18444e ("x86/fault: Plumb error code and fault address through to fault handlers")

from the tip tree and commits:

  6ace1098a68c ("signal/x86/traps: Factor out show_signal")
  79e21d654093 ("signal/x86/traps: Move more code into do_trap_no_signal so it can be reused")

from the userns tree.

I fixed it up (see below) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging.  You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

-- 
Cheers,
Stephen Rothwell

diff --cc arch/x86/kernel/traps.c
index 5bd0a997d81e,34a327f35976..000000000000
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@@ -202,11 -202,8 +202,8 @@@ do_trap_no_signal(struct task_struct *t
  						error_code, trapnr))
  				return 0;
  		}
- 		return -1;
- 	}
- 
- 	if (!user_mode(regs)) {
+ 	} else if (!user_mode(regs)) {
 -		if (fixup_exception(regs, trapnr))
 +		if (fixup_exception(regs, trapnr, error_code, 0))
  			return 0;
  
  		tsk->thread.error_code = error_code;
@@@ -560,19 -540,9 +544,19 @@@ do_general_protection(struct pt_regs *r
  
  		tsk->thread.error_code = error_code;
  		tsk->thread.trap_nr = X86_TRAP_GP;
 +
 +		/*
 +		 * To be potentially processing a kprobe fault and to
 +		 * trust the result from kprobe_running(), we have to
 +		 * be non-preemptible.
 +		 */
 +		if (!preemptible() && kprobe_running() &&
 +		    kprobe_fault_handler(regs, X86_TRAP_GP))
 +			return;
 +
- 		if (notify_die(DIE_GPF, "general protection fault", regs, error_code,
+ 		if (notify_die(DIE_GPF, desc, regs, error_code,
  			       X86_TRAP_GP, SIGSEGV) != NOTIFY_STOP)
- 			die("general protection fault", regs, error_code);
+ 			die(desc, regs, error_code);
  		return;
  	}