Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Catalin Marinas:

 - Correctly mask out bits 63:60 in a kernel tag check fault address
   (specified as unknown by the architecture). Previously they were just
   zeroed but for kernel pointers they need to be all ones.

 - Fix a panic (unexpected kernel BRK exception) caused by kprobes being
   reentered due to an interrupt.

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: kprobes: Fix Uexpected kernel BRK exception at EL1
  kasan, arm64: fix pointer tags in KASAN reports

Author: torvalds

arch/arm64/kernel/probes/kprobes.c

@@ -352,8 +352,8 @@ kprobe_breakpoint_ss_handler(struct pt_regs *regs, unsigned int esr)
 	unsigned long addr = instruction_pointer(regs);
 	struct kprobe *cur = kprobe_running();
 
-	if (cur && (kcb->kprobe_status == KPROBE_HIT_SS)
-	    && ((unsigned long)&cur->ainsn.api.insn[1] == addr)) {
+	if (cur && (kcb->kprobe_status & (KPROBE_HIT_SS | KPROBE_REENTER)) &&
+	    ((unsigned long)&cur->ainsn.api.insn[1] == addr)) {
 		kprobes_restore_local_irqflag(kcb, regs);
 		post_kprobe_handler(cur, kcb, regs);
 

arch/arm64/mm/fault.c

@@ -709,10 +709,11 @@ static int do_tag_check_fault(unsigned long far, unsigned int esr,
 			      struct pt_regs *regs)
 {
 	/*
-	 * The architecture specifies that bits 63:60 of FAR_EL1 are UNKNOWN for tag
-	 * check faults. Mask them out now so that userspace doesn't see them.
+	 * The architecture specifies that bits 63:60 of FAR_EL1 are UNKNOWN
+	 * for tag check faults. Set them to corresponding bits in the untagged
+	 * address.
 	 */
-	far &= (1UL << 60) - 1;
+	far = (__untagged_addr(far) & ~MTE_TAG_MASK) | (far & MTE_TAG_MASK);
 	do_bad_area(far, esr, regs);
 	return 0;
 }