Commit 4ef87322 authored Apr 01, 2020 by Peter Xu Committed by Linus Torvalds Apr 02, 2020

mm: introduce fault_signal_pending()

For most architectures, we've got a quick path to detect fatal signal
after a handle_mm_fault().  Introduce a helper for that quick path.

It cleans the current codes a bit so we don't need to duplicate the same
check across archs.  More importantly, this will be an unified place that
we handle the signal immediately right after an interrupted page fault, so
it'll be much easier for us if we want to change the behavior of handling
signals later on for all the archs.

Note that currently only part of the archs are using this new helper,
because some archs have their own way to handle signals.  In the follow up
patches, we'll try to apply this helper to all the rest of archs.

Another note is that the "regs" parameter in the new helper is not used
yet.  It'll be used very soon.  Now we kept it in this patch only to avoid
touching all the archs again in the follow up patches.

[peterx@redhat.com: fix sparse warnings]
  Link: http://lkml.kernel.org/r/20200311145921.GD479302@xz-x1


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/20200220155353.8676-4-peterx@redhat.com


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

parent ad415db8

arch/alpha/mm/fault.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -150,7 +150,7 @@ retry:
		the fault. */
		fault = handle_mm_fault(vma, address, flags);

		if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
		if (fault_signal_pending(fault, regs))
		return;

		if (unlikely(fault & VM_FAULT_ERROR)) {

arch/arm/mm/fault.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -295,7 +295,7 @@ retry:
		* signal first. We do not need to release the mmap_sem because
		* it would already be released in __lock_page_or_retry in
		* mm/filemap.c. */
		if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) {
		if (fault_signal_pending(fault, regs)) {
		if (!user_mode(regs))
		goto no_context;
		return 0;

arch/hexagon/mm/vm_fault.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -91,7 +91,7 @@ good_area:

		fault = handle_mm_fault(vma, address, flags);

		if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
		if (fault_signal_pending(fault, regs))
		return;

		/* The most common case -- we are done. */

arch/ia64/mm/fault.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -141,7 +141,7 @@ retry:
		*/
		fault = handle_mm_fault(vma, address, flags);

		if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
		if (fault_signal_pending(fault, regs))
		return;

		if (unlikely(fault & VM_FAULT_ERROR)) {

arch/m68k/mm/fault.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -138,7 +138,7 @@ good_area:
		fault = handle_mm_fault(vma, address, flags);
		pr_debug("handle_mm_fault returns %x\n", fault);

		if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
		if (fault_signal_pending(fault, regs))
		return 0;

		if (unlikely(fault & VM_FAULT_ERROR)) {

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