arm64: consolidate signal injection on emulation errors

The code for injecting a signal into userland if a trapped instruction
fails emulation due to a _userland_ error (like an illegal address)
will be used more often with the next patch.
Factor out the core functionality into a separate function and use
that both for the existing trap handler and for the deprecated
instructions emulation.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
[catalin.marinas@arm.com: s/set_segfault/arm64_notify_segfault/]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c
index c37202c..fab5603 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -316,28 +316,6 @@
  */
 #define TYPE_SWPB (1 << 22)
 
-/*
- * Set up process info to signal segmentation fault - called on access error.
- */
-static void set_segfault(struct pt_regs *regs, unsigned long addr)
-{
-	siginfo_t info;
-
-	down_read(&current->mm->mmap_sem);
-	if (find_vma(current->mm, addr) == NULL)
-		info.si_code = SEGV_MAPERR;
-	else
-		info.si_code = SEGV_ACCERR;
-	up_read(&current->mm->mmap_sem);
-
-	info.si_signo = SIGSEGV;
-	info.si_errno = 0;
-	info.si_addr  = (void *) instruction_pointer(regs);
-
-	pr_debug("SWP{B} emulation: access caused memory abort!\n");
-	arm64_notify_die("Illegal memory access", regs, &info, 0);
-}
-
 static int emulate_swpX(unsigned int address, unsigned int *data,
 			unsigned int type)
 {
@@ -430,7 +408,8 @@
 	return 0;
 
 fault:
-	set_segfault(regs, address);
+	pr_debug("SWP{B} emulation: access caused memory abort!\n");
+	arm64_notify_segfault(regs, address);
 
 	return 0;
 }