Snap for 5631102 from dd5d5c1d63ab8024d94ceb18567287c6c6627922 to qt-c2f2-release

Change-Id: I85195aa7049abc780614bd999b4088f19f6686ab
diff --git a/tools/testing/selftests/x86/syscall_arg_fault.c b/tools/testing/selftests/x86/syscall_arg_fault.c
index 7db4fc9..d2548401 100644
--- a/tools/testing/selftests/x86/syscall_arg_fault.c
+++ b/tools/testing/selftests/x86/syscall_arg_fault.c
@@ -43,7 +43,7 @@
 
 static volatile sig_atomic_t n_errs;
 
-static void sigsegv(int sig, siginfo_t *info, void *ctx_void)
+static void sigsegv_or_sigbus(int sig, siginfo_t *info, void *ctx_void)
 {
 	ucontext_t *ctx = (ucontext_t*)ctx_void;
 
@@ -73,7 +73,13 @@
 	if (sigaltstack(&stack, NULL) != 0)
 		err(1, "sigaltstack");
 
-	sethandler(SIGSEGV, sigsegv, SA_ONSTACK);
+	sethandler(SIGSEGV, sigsegv_or_sigbus, SA_ONSTACK);
+	/*
+	 * The actual exception can vary.  On Atom CPUs, we get #SS
+	 * instead of #PF when the vDSO fails to access the stack when
+	 * ESP is too close to 2^32, and #SS causes SIGBUS.
+	 */
+	sethandler(SIGBUS, sigsegv_or_sigbus, SA_ONSTACK);
 	sethandler(SIGILL, sigill, SA_ONSTACK);
 
 	/*