Merge tag 'arc-5.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC architecture updates from Vineet Gupta:

 - Perf support for raw events

 - boot log printing: return stack, action points

 - fix memset to avoid prefetchw bleeding past end of buffer

 - do_page_fault fix for mmap_sem held while returning to userspace

 - other misc fixes

* tag 'arc-5.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARCv2: lib: memeset: fix doing prefetchw outside of buffer
  ARC: mm: do_page_fault fixes #1: relinquish mmap_sem if signal arrives while handle_mm_fault
  ARC: show_regs: lockdep: re-enable preemption
  ARC: show_regs: lockdep: avoid page allocator...
  ARC: perf: avoid kernel killing where it is possible
  ARC: perf: move HW events mapping to separate function
  ARC: perf: introduce Kernel PMU events support
  ARC: perf: trivial code cleanup
  ARC: perf: map generic branches to correct hardware condition
  ARC: adjust memblock_reserve of kernel memory
  arc: remove redundant kernel-space generic-y
  ARC: fix __ffs return value to avoid build warnings
  ARC: boot log: print Action point details
  ARCv2: boot log: BPU return stack depth

1 files changed, 9 insertions, 4 deletions

diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c
index a1d723197084..8df1638259f3 100644
--- a/arch/arc/mm/fault.c
+++ b/arch/arc/mm/fault.c
@@ -141,12 +141,17 @@ good_area:
 	 */
 	fault = handle_mm_fault(vma, address, flags);
 
-	/* If Pagefault was interrupted by SIGKILL, exit page fault "early" */
 	if (fatal_signal_pending(current)) {
-		if ((fault & VM_FAULT_ERROR) && !(fault & VM_FAULT_RETRY))
-			up_read(&mm->mmap_sem);
-		if (user_mode(regs))
+
+		/*
+		 * if fault retry, mmap_sem already relinquished by core mm
+		 * so OK to return to user mode (with signal handled first)
+		 */
+		if (fault & VM_FAULT_RETRY) {
+			if (!user_mode(regs))
+				goto no_context;
 			return;
+		}
 	}
 
 	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);