From: Peter Xu <pet...@redhat.com> 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 <pet...@redhat.com> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Tested-by: Brian Geffon <bgef...@google.com> Cc: Andrea Arcangeli <aarca...@redhat.com> Cc: Bobby Powers <bobbypow...@gmail.com> Cc: David Hildenbrand <da...@redhat.com> Cc: Denis Plotnikov <dplotni...@virtuozzo.com> Cc: "Dr . David Alan Gilbert" <dgilb...@redhat.com> Cc: Hugh Dickins <hu...@google.com> Cc: Jerome Glisse <jgli...@redhat.com> Cc: Johannes Weiner <han...@cmpxchg.org> Cc: "Kirill A . Shutemov" <kir...@shutemov.name> Cc: Martin Cracauer <craca...@cons.org> Cc: Marty McFadden <mcfadd...@llnl.gov> Cc: Matthew Wilcox <wi...@infradead.org> Cc: Maya Gokhale <gokha...@llnl.gov> Cc: Mel Gorman <mgor...@suse.de> Cc: Mike Kravetz <mike.krav...@oracle.com> Cc: Mike Rapoport <r...@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xe...@openvz.org> Link: http://lkml.kernel.org/r/20200220155353.8676-5-pet...@redhat.com Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> https://jira.sw.ru/browse/PSBM-102938 (cherry picked from commit 39678191cd8988c811813baf4c97b43bf46094e4) Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com> --- arch/x86/mm/fault.c | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index cdafd5fa6d0a..8e71ebad64a1 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1405,27 +1405,25 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code, 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, 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, error_code, address, SIGBUS, BUS_ADRERR); - return; + flags &= ~FAULT_FLAG_ALLOW_RETRY; + flags |= FAULT_FLAG_TRIED; + goto retry; } up_read(&mm->mmap_sem); -- 2.25.3 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
