[Devel] [PATCH RHEL8 COMMIT] powerpc/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 ca6f9c2820bdea5c680978047ad96b4902a70f52
Author: Peter Xu <peterx at redhat.com>
Date:   Mon Apr 20 10:34:13 2020 +0300

    powerpc/mm: use helper fault_signal_pending()
    
    Let powerpc code to use the new helper, by moving the signal handling
    earlier before the retry logic.
    
    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/20200220160222.9422-1-peterx@redhat.com
    Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
    
    https://jira.sw.ru/browse/PSBM-102938
    (cherry picked from commit c9a0dad162014182867f81b28bb7a4b691d65595)
    Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
---
 arch/powerpc/mm/fault.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index b1ca7a0974e3..a6513c463169 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -557,6 +557,9 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,
 
 	major |= fault & VM_FAULT_MAJOR;
 
+	if (fault_signal_pending(fault, regs))
+		return user_mode(regs) ? 0 : SIGBUS;
+
 	/*
 	 * Handle the retry right now, the mmap_sem has been released in that
 	 * case.
@@ -570,15 +573,8 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,
 			 */
 			flags &= ~FAULT_FLAG_ALLOW_RETRY;
 			flags |= FAULT_FLAG_TRIED;
-			if (!fatal_signal_pending(current))
-				goto retry;
+			goto retry;
 		}
-
-		/*
-		 * User mode? Just return to handle the fatal exception otherwise
-		 * return to bad_page_fault
-		 */
-		return is_user ? 0 : SIGBUS;
 	}
 
 	up_read(&current->mm->mmap_sem);