Commit 6456a2a6 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Borislav Petkov
Browse files

x86/fault: Rename no_context() to kernelmode_fixup_or_oops() 



The name no_context() has never been very clear.  It's only called for
faults from kernel mode, so rename it and change the no-longer-useful
user_mode(regs) check to a WARN_ON_ONCE.

Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/c21940efe676024bb4bc721f7d70c29c420e127e.1612924255.git.luto@kernel.org
parent 5042d40a

arch/x86/mm/fault.c

+10 −18
Original line number Diff line number Diff line
@@ -730,17 +730,10 @@ page_fault_oops(struct pt_regs *regs, unsigned long error_code, 
}



static noinline void

no_context(struct pt_regs *regs, unsigned long error_code,

kernelmode_fixup_or_oops(struct pt_regs *regs, unsigned long error_code,

			 unsigned long address, int signal, int si_code)

{

	if (user_mode(regs)) {

		/*

		 * This is an implicit supervisor-mode access from user

		 * mode.  Bypass all the kernel-mode recovery code and just

		 * OOPS.

		 */

		goto oops;

	}

	WARN_ON_ONCE(user_mode(regs));



	/* Are we prepared to handle this kernel fault? */

	if (fixup_exception(regs, X86_TRAP_PF, error_code, address)) {
@@ -780,7 +773,6 @@ no_context(struct pt_regs *regs, unsigned long error_code, 
	if (is_prefetch(regs, error_code, address))

		return;



oops:

	page_fault_oops(regs, error_code, address);

}
@@ -827,7 +819,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code, 
	struct task_struct *tsk = current;



	if (!user_mode(regs)) {

		no_context(regs, error_code, address, pkey, si_code);

		kernelmode_fixup_or_oops(regs, error_code, address, pkey, si_code);

		return;

	}
@@ -959,7 +951,7 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address, 
{

	/* Kernel mode? Handle exceptions or die: */

	if (!user_mode(regs)) {

		no_context(regs, error_code, address, SIGBUS, BUS_ADRERR);

		kernelmode_fixup_or_oops(regs, error_code, address, SIGBUS, BUS_ADRERR);

		return;

	}
@@ -1421,8 +1413,8 @@ void do_user_addr_fault(struct pt_regs *regs, 
		 * has unlocked the mm for us if we get here.

		 */

		if (!user_mode(regs))

			no_context(regs, error_code, address, SIGBUS,

				   BUS_ADRERR);

			kernelmode_fixup_or_oops(regs, error_code, address,

						 SIGBUS, BUS_ADRERR);

		return;

	}
@@ -1442,14 +1434,14 @@ void do_user_addr_fault(struct pt_regs *regs, 
		return;



	if (fatal_signal_pending(current) && !user_mode(regs)) {

		no_context(regs, error_code, address, 0, 0);

		kernelmode_fixup_or_oops(regs, error_code, address, 0, 0);

		return;

	}



	if (fault & VM_FAULT_OOM) {

		/* Kernel mode? Handle exceptions or die: */

		if (!user_mode(regs)) {

			no_context(regs, error_code, address,

			kernelmode_fixup_or_oops(regs, error_code, address,

						 SIGSEGV, SEGV_MAPERR);

			return;

		}