[Devel] [PATCH RHEL8 COMMIT] sh/mm: use helper fault_signal_pending()

[Konstantin Khorenko]

The commit is pushed to "branch-rh8-4.18.0-80.1.2.vz8.3.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh8-4.18.0-80.1.2.vz8.3.6
------>
commit 509ffe21902684063f853e875e4147fe7192c6dc
Author: Peter Xu <peterx at redhat.com>
Date:   Mon Apr 20 10:34:14 2020 +0300

    sh/mm: use helper fault_signal_pending()
    
    Let SH to use the new fault_signal_pending() helper.  Here we'll need to
    move the up_read() out because that's actually needed as long as !RETRY
    cases.  At the meantime we can drop all the rest of up_read()s now (which
    seems to be cleaner).
    
    Signed-off-by: Peter Xu <peterx at redhat.com>
    Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
    Tested-by: Brian Geffon <bgeffon at google.com>
    Cc: Andrea Arcangeli <aarcange at redhat.com>
    Cc: Bobby Powers <bobbypowers at gmail.com>
    Cc: David Hildenbrand <david at redhat.com>
    Cc: Denis Plotnikov <dplotnikov at virtuozzo.com>
    Cc: "Dr . David Alan Gilbert" <dgilbert at redhat.com>
    Cc: Hugh Dickins <hughd at google.com>
    Cc: Jerome Glisse <jglisse at redhat.com>
    Cc: Johannes Weiner <hannes at cmpxchg.org>
    Cc: "Kirill A . Shutemov" <kirill at shutemov.name>
    Cc: Martin Cracauer <cracauer at cons.org>
    Cc: Marty McFadden <mcfadden8 at llnl.gov>
    Cc: Matthew Wilcox <willy at infradead.org>
    Cc: Maya Gokhale <gokhale2 at llnl.gov>
    Cc: Mel Gorman <mgorman at suse.de>
    Cc: Mike Kravetz <mike.kravetz at oracle.com>
    Cc: Mike Rapoport <rppt at linux.vnet.ibm.com>
    Cc: Pavel Emelyanov <xemul at openvz.org>
    Link: http://lkml.kernel.org/r/20200220160226.9550-1-peterx@redhat.com
    Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
    
    https://jira.sw.ru/browse/PSBM-102938
    (cherry picked from commit fb027ada051a9e2d70a069b2aa62fb6f52100bbf)
    Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
---
 arch/sh/mm/fault.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c
index b8e7bb84b6b1..e1a257a83fb6 100644
--- a/arch/sh/mm/fault.c
+++ b/arch/sh/mm/fault.c
@@ -319,25 +319,25 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code,
 	 * Pagefault was interrupted by SIGKILL. We have no reason to
 	 * continue pagefault.
 	 */
-	if (fatal_signal_pending(current)) {
-		if (!(fault & VM_FAULT_RETRY))
-			up_read(&current->mm->mmap_sem);
+	if (fault_signal_pending(fault, regs)) {
 		if (!user_mode(regs))
 			no_context(regs, error_code, address);
 		return 1;
 	}
 
+	/* Release mmap_sem first if necessary */
+	if (!(fault & VM_FAULT_RETRY))
+		up_read(&current->mm->mmap_sem);
+
 	if (!(fault & VM_FAULT_ERROR))
 		return 0;
 
 	if (fault & VM_FAULT_OOM) {
 		/* Kernel mode? Handle exceptions or die: */
 		if (!user_mode(regs)) {
-			up_read(&current->mm->mmap_sem);
 			no_context(regs, error_code, address);
 			return 1;
 		}
-		up_read(&current->mm->mmap_sem);
 
 		/*
 		 * We ran out of memory, call the OOM killer, and return the