Commit 39678191 authored Apr 01, 2020 by Peter Xu Committed by Linus Torvalds Apr 02, 2020

x86/mm: use helper fault_signal_pending()

Let's move the fatal signal check even earlier so that we can directly use
the new fault_signal_pending() in x86 mm code.

Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Brian Geffon <bgeffon@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Denis Plotnikov <dplotnikov@virtuozzo.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Martin Cracauer <cracauer@cons.org>
Cc: Marty McFadden <mcfadden8@llnl.gov>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Maya Gokhale <gokhale2@llnl.gov>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Link: http://lkml.kernel.org/r/20200220155353.8676-5-peterx@redhat.com

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 4ef87322

arch/x86/mm/fault.c

+13 −15

Original line number	Diff line number	Diff line
		@@ -1464,29 +1464,27 @@ void do_user_addr_fault(struct pt_regs *regs,
		fault = handle_mm_fault(vma, address, flags);
		major \|= fault & VM_FAULT_MAJOR;

		/* Quick path to respond to signals */
		if (fault_signal_pending(fault, regs)) {
		if (!user_mode(regs))
		no_context(regs, hw_error_code, address, SIGBUS,
		BUS_ADRERR);
		return;
		}

		/*
		* If we need to retry the mmap_sem has already been released,
		* and if there is a fatal signal pending there is no guarantee
		* that we made any progress. Handle this case first.
		*/
		if (unlikely(fault & VM_FAULT_RETRY)) {
		if (unlikely((fault & VM_FAULT_RETRY) &&
		(flags & FAULT_FLAG_ALLOW_RETRY))) {
		/* Retry at most once */
		if (flags & FAULT_FLAG_ALLOW_RETRY) {
		flags &= ~FAULT_FLAG_ALLOW_RETRY;
		flags \|= FAULT_FLAG_TRIED;
		if (!fatal_signal_pending(tsk))
		goto retry;
		}

		/* User mode? Just return to handle the fatal exception */
		if (flags & FAULT_FLAG_USER)
		return;

		/* Not returning to user mode? Handle exceptions or die: */
		no_context(regs, hw_error_code, address, SIGBUS, BUS_ADRERR);
		return;
		}

		up_read(&mm->mmap_sem);
		if (unlikely(fault & VM_FAULT_ERROR)) {
		mm_fault_error(regs, hw_error_code, address, fault);