aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/tools/testing/selftests/x86
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2019-09-16 19:06:29 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-09-16 19:06:29 -0700
commite0d60a1e68a3fbf42cdf3546004e00230d9048ba (patch)
treee283f864ee0d53fa8df68701b463365e6b73683b /tools/testing/selftests/x86
parentMerge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (diff)
parentx86/syscalls: Split the x32 syscalls into their own table (diff)
downloadwireguard-linux-e0d60a1e68a3fbf42cdf3546004e00230d9048ba.tar.xz
wireguard-linux-e0d60a1e68a3fbf42cdf3546004e00230d9048ba.zip
Merge branch 'x86-entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 entry updates from Ingo Molnar: "This contains x32 and compat syscall improvements, the biggest one of which splits x32 syscalls into their own table, which allows new syscalls to share the x32 and x86-64 number - which turns the 512-547 special syscall numbers range into a legacy wart that won't be extended going forward" * 'x86-entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/syscalls: Split the x32 syscalls into their own table x86/syscalls: Disallow compat entries for all types of 64-bit syscalls x86/syscalls: Use the compat versions of rt_sigsuspend() and rt_sigprocmask() x86/syscalls: Make __X32_SYSCALL_BIT be unsigned long
Diffstat (limited to 'tools/testing/selftests/x86')
-rw-r--r--tools/testing/selftests/x86/Makefile2
-rw-r--r--tools/testing/selftests/x86/syscall_numbering.c89
2 files changed, 90 insertions, 1 deletions
diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile
index 3bc5b744e644..5d49bfec1e9a 100644
--- a/tools/testing/selftests/x86/Makefile
+++ b/tools/testing/selftests/x86/Makefile
@@ -17,7 +17,7 @@ TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt test_mremap
TARGETS_C_32BIT_ONLY := entry_from_vm86 test_syscall_vdso unwind_vdso \
test_FCMOV test_FCOMI test_FISTTP \
vdso_restorer
-TARGETS_C_64BIT_ONLY := fsgsbase sysret_rip
+TARGETS_C_64BIT_ONLY := fsgsbase sysret_rip syscall_numbering
# Some selftests require 32bit support enabled also on 64bit systems
TARGETS_C_32BIT_NEEDED := ldt_gdt ptrace_syscall
diff --git a/tools/testing/selftests/x86/syscall_numbering.c b/tools/testing/selftests/x86/syscall_numbering.c
new file mode 100644
index 000000000000..d6b09cb1aa2c
--- /dev/null
+++ b/tools/testing/selftests/x86/syscall_numbering.c
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * syscall_arg_fault.c - tests faults 32-bit fast syscall stack args
+ * Copyright (c) 2018 Andrew Lutomirski
+ */
+
+#define _GNU_SOURCE
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <errno.h>
+#include <unistd.h>
+#include <syscall.h>
+
+static int nerrs;
+
+#define X32_BIT 0x40000000UL
+
+static void check_enosys(unsigned long nr, bool *ok)
+{
+ /* If this fails, a segfault is reasonably likely. */
+ fflush(stdout);
+
+ long ret = syscall(nr, 0, 0, 0, 0, 0, 0);
+ if (ret == 0) {
+ printf("[FAIL]\tsyscall %lu succeeded, but it should have failed\n", nr);
+ *ok = false;
+ } else if (errno != ENOSYS) {
+ printf("[FAIL]\tsyscall %lu had error code %d, but it should have reported ENOSYS\n", nr, errno);
+ *ok = false;
+ }
+}
+
+static void test_x32_without_x32_bit(void)
+{
+ bool ok = true;
+
+ /*
+ * Syscalls 512-547 are "x32" syscalls. They are intended to be
+ * called with the x32 (0x40000000) bit set. Calling them without
+ * the x32 bit set is nonsense and should not work.
+ */
+ printf("[RUN]\tChecking syscalls 512-547\n");
+ for (int i = 512; i <= 547; i++)
+ check_enosys(i, &ok);
+
+ /*
+ * Check that a handful of 64-bit-only syscalls are rejected if the x32
+ * bit is set.
+ */
+ printf("[RUN]\tChecking some 64-bit syscalls in x32 range\n");
+ check_enosys(16 | X32_BIT, &ok); /* ioctl */
+ check_enosys(19 | X32_BIT, &ok); /* readv */
+ check_enosys(20 | X32_BIT, &ok); /* writev */
+
+ /*
+ * Check some syscalls with high bits set.
+ */
+ printf("[RUN]\tChecking numbers above 2^32-1\n");
+ check_enosys((1UL << 32), &ok);
+ check_enosys(X32_BIT | (1UL << 32), &ok);
+
+ if (!ok)
+ nerrs++;
+ else
+ printf("[OK]\tThey all returned -ENOSYS\n");
+}
+
+int main()
+{
+ /*
+ * Anyone diagnosing a failure will want to know whether the kernel
+ * supports x32. Tell them.
+ */
+ printf("\tChecking for x32...");
+ fflush(stdout);
+ if (syscall(39 | X32_BIT, 0, 0, 0, 0, 0, 0) >= 0) {
+ printf(" supported\n");
+ } else if (errno == ENOSYS) {
+ printf(" not supported\n");
+ } else {
+ printf(" confused\n");
+ }
+
+ test_x32_without_x32_bit();
+
+ return nerrs ? 1 : 0;
+}