From 03dd4cb26d967f9588437b0fc9cc0e8353322bb7 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Fri, 25 Mar 2016 03:53:42 -0300
Subject: Linux-libre 4.5-gnu
---
tools/testing/selftests/x86/Makefile | 6 +-
tools/testing/selftests/x86/vdso_restorer.c | 88 +++++++++++++++++++++++++++++
2 files changed, 92 insertions(+), 2 deletions(-)
create mode 100644 tools/testing/selftests/x86/vdso_restorer.c
(limited to 'tools/testing/selftests/x86')
diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile
index eabcff411..d0c473f65 100644
--- a/tools/testing/selftests/x86/Makefile
+++ b/tools/testing/selftests/x86/Makefile
@@ -4,9 +4,11 @@ include ../lib.mk
.PHONY: all all_32 all_64 warn_32bit_failure clean
-TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs ldt_gdt syscall_nt ptrace_syscall
+TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt ptrace_syscall
TARGETS_C_32BIT_ONLY := entry_from_vm86 syscall_arg_fault sigreturn test_syscall_vdso unwind_vdso \
- test_FCMOV test_FCOMI test_FISTTP
+ test_FCMOV test_FCOMI test_FISTTP \
+ ldt_gdt \
+ vdso_restorer
TARGETS_C_32BIT_ALL := $(TARGETS_C_BOTHBITS) $(TARGETS_C_32BIT_ONLY)
BINARIES_32 := $(TARGETS_C_32BIT_ALL:%=%_32)
diff --git a/tools/testing/selftests/x86/vdso_restorer.c b/tools/testing/selftests/x86/vdso_restorer.c
new file mode 100644
index 000000000..cb038424a
--- /dev/null
+++ b/tools/testing/selftests/x86/vdso_restorer.c
@@ -0,0 +1,88 @@
+/*
+ * vdso_restorer.c - tests vDSO-based signal restore
+ * Copyright (c) 2015 Andrew Lutomirski
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * This makes sure that sa_restorer == NULL keeps working on 32-bit
+ * configurations. Modern glibc doesn't use it under any circumstances,
+ * so it's easy to overlook breakage.
+ *
+ * 64-bit userspace has never supported sa_restorer == NULL, so this is
+ * 32-bit only.
+ */
+
+#define _GNU_SOURCE
+
+#include <err.h>
+#include <stdio.h>
+#include <string.h>
+#include <signal.h>
+#include <unistd.h>
+#include <syscall.h>
+#include <sys/syscall.h>
+
+/* Open-code this -- the headers are too messy to easily use them. */
+struct real_sigaction {
+ void *handler;
+ unsigned long flags;
+ void *restorer;
+ unsigned int mask[2];
+};
+
+static volatile sig_atomic_t handler_called;
+
+static void handler_with_siginfo(int sig, siginfo_t *info, void *ctx_void)
+{
+ handler_called = 1;
+}
+
+static void handler_without_siginfo(int sig)
+{
+ handler_called = 1;
+}
+
+int main()
+{
+ int nerrs = 0;
+ struct real_sigaction sa;
+
+ memset(&sa, 0, sizeof(sa));
+ sa.handler = handler_with_siginfo;
+ sa.flags = SA_SIGINFO;
+ sa.restorer = NULL; /* request kernel-provided restorer */
+
+ if (syscall(SYS_rt_sigaction, SIGUSR1, &sa, NULL, 8) != 0)
+ err(1, "raw rt_sigaction syscall");
+
+ raise(SIGUSR1);
+
+ if (handler_called) {
+ printf("[OK]\tSA_SIGINFO handler returned successfully\n");
+ } else {
+ printf("[FAIL]\tSA_SIGINFO handler was not called\n");
+ nerrs++;
+ }
+
+ sa.flags = 0;
+ sa.handler = handler_without_siginfo;
+ if (syscall(SYS_sigaction, SIGUSR1, &sa, 0) != 0)
+ err(1, "raw sigaction syscall");
+ handler_called = 0;
+
+ raise(SIGUSR1);
+
+ if (handler_called) {
+ printf("[OK]\t!SA_SIGINFO handler returned successfully\n");
+ } else {
+ printf("[FAIL]\t!SA_SIGINFO handler was not called\n");
+ nerrs++;
+ }
+}
--
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