--- /dev/null
+From 352909b49ba0d74929b96af6dfbefc854ab6ebb5 Mon Sep 17 00:00:00 2001
+From: Andy Lutomirski <luto@kernel.org>
+Date: Thu, 11 Jan 2018 17:16:51 -0800
+Subject: selftests/x86: Add test_vsyscall
+
+From: Andy Lutomirski <luto@kernel.org>
+
+commit 352909b49ba0d74929b96af6dfbefc854ab6ebb5 upstream.
+
+This tests that the vsyscall entries do what they're expected to do.
+It also confirms that attempts to read the vsyscall page behave as
+expected.
+
+If changes are made to the vsyscall code or its memory map handling,
+running this test in all three of vsyscall=none, vsyscall=emulate,
+and vsyscall=native are helpful.
+
+(Because it's easy, this also compares the vsyscall results to their
+ vDSO equivalents.)
+
+Note to KAISER backporters: please test this under all three
+vsyscall modes. Also, in the emulate and native modes, make sure
+that test_vsyscall_64 agrees with the command line or config
+option as to which mode you're in. It's quite easy to mess up
+the kernel such that native mode accidentally emulates
+or vice versa.
+
+Greg, etc: please backport this to all your Meltdown-patched
+kernels. It'll help make sure the patches didn't regress
+vsyscalls.
+
+CSigned-off-by: Andy Lutomirski <luto@kernel.org>
+Cc: Andy Lutomirski <luto@kernel.org>
+Cc: Borislav Petkov <bp@alien8.de>
+Cc: Dave Hansen <dave.hansen@linux.intel.com>
+Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Cc: H. Peter Anvin <hpa@zytor.com>
+Cc: Hugh Dickins <hughd@google.com>
+Cc: Josh Poimboeuf <jpoimboe@redhat.com>
+Cc: Juergen Gross <jgross@suse.com>
+Cc: Kees Cook <keescook@chromium.org>
+Cc: Linus Torvalds <torvalds@linux-foundation.org>
+Cc: Peter Zijlstra <peterz@infradead.org>
+Cc: Thomas Gleixner <tglx@linutronix.de>
+Cc: stable@vger.kernel.org
+Link: http://lkml.kernel.org/r/2b9c5a174c1d60fd7774461d518aa75598b1d8fd.1515719552.git.luto@kernel.org
+Signed-off-by: Ingo Molnar <mingo@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ tools/testing/selftests/x86/test_vsyscall.c | 500 ++++++++++++++++++++++++++++
+ 1 file changed, 500 insertions(+)
+
+--- /dev/null
++++ b/tools/testing/selftests/x86/test_vsyscall.c
+@@ -0,0 +1,500 @@
++/* SPDX-License-Identifier: GPL-2.0 */
++
++#define _GNU_SOURCE
++
++#include <stdio.h>
++#include <sys/time.h>
++#include <time.h>
++#include <stdlib.h>
++#include <sys/syscall.h>
++#include <unistd.h>
++#include <dlfcn.h>
++#include <string.h>
++#include <inttypes.h>
++#include <signal.h>
++#include <sys/ucontext.h>
++#include <errno.h>
++#include <err.h>
++#include <sched.h>
++#include <stdbool.h>
++#include <setjmp.h>
++
++#ifdef __x86_64__
++# define VSYS(x) (x)
++#else
++# define VSYS(x) 0
++#endif
++
++#ifndef SYS_getcpu
++# ifdef __x86_64__
++# define SYS_getcpu 309
++# else
++# define SYS_getcpu 318
++# endif
++#endif
++
++static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *),
++ int flags)
++{
++ struct sigaction sa;
++ memset(&sa, 0, sizeof(sa));
++ sa.sa_sigaction = handler;
++ sa.sa_flags = SA_SIGINFO | flags;
++ sigemptyset(&sa.sa_mask);
++ if (sigaction(sig, &sa, 0))
++ err(1, "sigaction");
++}
++
++/* vsyscalls and vDSO */
++bool should_read_vsyscall = false;
++
++typedef long (*gtod_t)(struct timeval *tv, struct timezone *tz);
++gtod_t vgtod = (gtod_t)VSYS(0xffffffffff600000);
++gtod_t vdso_gtod;
++
++typedef int (*vgettime_t)(clockid_t, struct timespec *);
++vgettime_t vdso_gettime;
++
++typedef long (*time_func_t)(time_t *t);
++time_func_t vtime = (time_func_t)VSYS(0xffffffffff600400);
++time_func_t vdso_time;
++
++typedef long (*getcpu_t)(unsigned *, unsigned *, void *);
++getcpu_t vgetcpu = (getcpu_t)VSYS(0xffffffffff600800);
++getcpu_t vdso_getcpu;
++
++static void init_vdso(void)
++{
++ void *vdso = dlopen("linux-vdso.so.1", RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
++ if (!vdso)
++ vdso = dlopen("linux-gate.so.1", RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
++ if (!vdso) {
++ printf("[WARN]\tfailed to find vDSO\n");
++ return;
++ }
++
++ vdso_gtod = (gtod_t)dlsym(vdso, "__vdso_gettimeofday");
++ if (!vdso_gtod)
++ printf("[WARN]\tfailed to find gettimeofday in vDSO\n");
++
++ vdso_gettime = (vgettime_t)dlsym(vdso, "__vdso_clock_gettime");
++ if (!vdso_gettime)
++ printf("[WARN]\tfailed to find clock_gettime in vDSO\n");
++
++ vdso_time = (time_func_t)dlsym(vdso, "__vdso_time");
++ if (!vdso_time)
++ printf("[WARN]\tfailed to find time in vDSO\n");
++
++ vdso_getcpu = (getcpu_t)dlsym(vdso, "__vdso_getcpu");
++ if (!vdso_getcpu) {
++ /* getcpu() was never wired up in the 32-bit vDSO. */
++ printf("[%s]\tfailed to find getcpu in vDSO\n",
++ sizeof(long) == 8 ? "WARN" : "NOTE");
++ }
++}
++
++static int init_vsys(void)
++{
++#ifdef __x86_64__
++ int nerrs = 0;
++ FILE *maps;
++ char line[128];
++ bool found = false;
++
++ maps = fopen("/proc/self/maps", "r");
++ if (!maps) {
++ printf("[WARN]\tCould not open /proc/self/maps -- assuming vsyscall is r-x\n");
++ should_read_vsyscall = true;
++ return 0;
++ }
++
++ while (fgets(line, sizeof(line), maps)) {
++ char r, x;
++ void *start, *end;
++ char name[128];
++ if (sscanf(line, "%p-%p %c-%cp %*x %*x:%*x %*u %s",
++ &start, &end, &r, &x, name) != 5)
++ continue;
++
++ if (strcmp(name, "[vsyscall]"))
++ continue;
++
++ printf("\tvsyscall map: %s", line);
++
++ if (start != (void *)0xffffffffff600000 ||
++ end != (void *)0xffffffffff601000) {
++ printf("[FAIL]\taddress range is nonsense\n");
++ nerrs++;
++ }
++
++ printf("\tvsyscall permissions are %c-%c\n", r, x);
++ should_read_vsyscall = (r == 'r');
++ if (x != 'x') {
++ vgtod = NULL;
++ vtime = NULL;
++ vgetcpu = NULL;
++ }
++
++ found = true;
++ break;
++ }
++
++ fclose(maps);
++
++ if (!found) {
++ printf("\tno vsyscall map in /proc/self/maps\n");
++ should_read_vsyscall = false;
++ vgtod = NULL;
++ vtime = NULL;
++ vgetcpu = NULL;
++ }
++
++ return nerrs;
++#else
++ return 0;
++#endif
++}
++
++/* syscalls */
++static inline long sys_gtod(struct timeval *tv, struct timezone *tz)
++{
++ return syscall(SYS_gettimeofday, tv, tz);
++}
++
++static inline int sys_clock_gettime(clockid_t id, struct timespec *ts)
++{
++ return syscall(SYS_clock_gettime, id, ts);
++}
++
++static inline long sys_time(time_t *t)
++{
++ return syscall(SYS_time, t);
++}
++
++static inline long sys_getcpu(unsigned * cpu, unsigned * node,
++ void* cache)
++{
++ return syscall(SYS_getcpu, cpu, node, cache);
++}
++
++static jmp_buf jmpbuf;
++
++static void sigsegv(int sig, siginfo_t *info, void *ctx_void)
++{
++ siglongjmp(jmpbuf, 1);
++}
++
++static double tv_diff(const struct timeval *a, const struct timeval *b)
++{
++ return (double)(a->tv_sec - b->tv_sec) +
++ (double)((int)a->tv_usec - (int)b->tv_usec) * 1e-6;
++}
++
++static int check_gtod(const struct timeval *tv_sys1,
++ const struct timeval *tv_sys2,
++ const struct timezone *tz_sys,
++ const char *which,
++ const struct timeval *tv_other,
++ const struct timezone *tz_other)
++{
++ int nerrs = 0;
++ double d1, d2;
++
++ if (tz_other && (tz_sys->tz_minuteswest != tz_other->tz_minuteswest || tz_sys->tz_dsttime != tz_other->tz_dsttime)) {
++ printf("[FAIL] %s tz mismatch\n", which);
++ nerrs++;
++ }
++
++ d1 = tv_diff(tv_other, tv_sys1);
++ d2 = tv_diff(tv_sys2, tv_other);
++ printf("\t%s time offsets: %lf %lf\n", which, d1, d2);
++
++ if (d1 < 0 || d2 < 0) {
++ printf("[FAIL]\t%s time was inconsistent with the syscall\n", which);
++ nerrs++;
++ } else {
++ printf("[OK]\t%s gettimeofday()'s timeval was okay\n", which);
++ }
++
++ return nerrs;
++}
++
++static int test_gtod(void)
++{
++ struct timeval tv_sys1, tv_sys2, tv_vdso, tv_vsys;
++ struct timezone tz_sys, tz_vdso, tz_vsys;
++ long ret_vdso = -1;
++ long ret_vsys = -1;
++ int nerrs = 0;
++
++ printf("[RUN]\ttest gettimeofday()\n");
++
++ if (sys_gtod(&tv_sys1, &tz_sys) != 0)
++ err(1, "syscall gettimeofday");
++ if (vdso_gtod)
++ ret_vdso = vdso_gtod(&tv_vdso, &tz_vdso);
++ if (vgtod)
++ ret_vsys = vgtod(&tv_vsys, &tz_vsys);
++ if (sys_gtod(&tv_sys2, &tz_sys) != 0)
++ err(1, "syscall gettimeofday");
++
++ if (vdso_gtod) {
++ if (ret_vdso == 0) {
++ nerrs += check_gtod(&tv_sys1, &tv_sys2, &tz_sys, "vDSO", &tv_vdso, &tz_vdso);
++ } else {
++ printf("[FAIL]\tvDSO gettimeofday() failed: %ld\n", ret_vdso);
++ nerrs++;
++ }
++ }
++
++ if (vgtod) {
++ if (ret_vsys == 0) {
++ nerrs += check_gtod(&tv_sys1, &tv_sys2, &tz_sys, "vsyscall", &tv_vsys, &tz_vsys);
++ } else {
++ printf("[FAIL]\tvsys gettimeofday() failed: %ld\n", ret_vsys);
++ nerrs++;
++ }
++ }
++
++ return nerrs;
++}
++
++static int test_time(void) {
++ int nerrs = 0;
++
++ printf("[RUN]\ttest time()\n");
++ long t_sys1, t_sys2, t_vdso = 0, t_vsys = 0;
++ long t2_sys1 = -1, t2_sys2 = -1, t2_vdso = -1, t2_vsys = -1;
++ t_sys1 = sys_time(&t2_sys1);
++ if (vdso_time)
++ t_vdso = vdso_time(&t2_vdso);
++ if (vtime)
++ t_vsys = vtime(&t2_vsys);
++ t_sys2 = sys_time(&t2_sys2);
++ if (t_sys1 < 0 || t_sys1 != t2_sys1 || t_sys2 < 0 || t_sys2 != t2_sys2) {
++ printf("[FAIL]\tsyscall failed (ret1:%ld output1:%ld ret2:%ld output2:%ld)\n", t_sys1, t2_sys1, t_sys2, t2_sys2);
++ nerrs++;
++ return nerrs;
++ }
++
++ if (vdso_time) {
++ if (t_vdso < 0 || t_vdso != t2_vdso) {
++ printf("[FAIL]\tvDSO failed (ret:%ld output:%ld)\n", t_vdso, t2_vdso);
++ nerrs++;
++ } else if (t_vdso < t_sys1 || t_vdso > t_sys2) {
++ printf("[FAIL]\tvDSO returned the wrong time (%ld %ld %ld)\n", t_sys1, t_vdso, t_sys2);
++ nerrs++;
++ } else {
++ printf("[OK]\tvDSO time() is okay\n");
++ }
++ }
++
++ if (vtime) {
++ if (t_vsys < 0 || t_vsys != t2_vsys) {
++ printf("[FAIL]\tvsyscall failed (ret:%ld output:%ld)\n", t_vsys, t2_vsys);
++ nerrs++;
++ } else if (t_vsys < t_sys1 || t_vsys > t_sys2) {
++ printf("[FAIL]\tvsyscall returned the wrong time (%ld %ld %ld)\n", t_sys1, t_vsys, t_sys2);
++ nerrs++;
++ } else {
++ printf("[OK]\tvsyscall time() is okay\n");
++ }
++ }
++
++ return nerrs;
++}
++
++static int test_getcpu(int cpu)
++{
++ int nerrs = 0;
++ long ret_sys, ret_vdso = -1, ret_vsys = -1;
++
++ printf("[RUN]\tgetcpu() on CPU %d\n", cpu);
++
++ cpu_set_t cpuset;
++ CPU_ZERO(&cpuset);
++ CPU_SET(cpu, &cpuset);
++ if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) {
++ printf("[SKIP]\tfailed to force CPU %d\n", cpu);
++ return nerrs;
++ }
++
++ unsigned cpu_sys, cpu_vdso, cpu_vsys, node_sys, node_vdso, node_vsys;
++ unsigned node = 0;
++ bool have_node = false;
++ ret_sys = sys_getcpu(&cpu_sys, &node_sys, 0);
++ if (vdso_getcpu)
++ ret_vdso = vdso_getcpu(&cpu_vdso, &node_vdso, 0);
++ if (vgetcpu)
++ ret_vsys = vgetcpu(&cpu_vsys, &node_vsys, 0);
++
++ if (ret_sys == 0) {
++ if (cpu_sys != cpu) {
++ printf("[FAIL]\tsyscall reported CPU %hu but should be %d\n", cpu_sys, cpu);
++ nerrs++;
++ }
++
++ have_node = true;
++ node = node_sys;
++ }
++
++ if (vdso_getcpu) {
++ if (ret_vdso) {
++ printf("[FAIL]\tvDSO getcpu() failed\n");
++ nerrs++;
++ } else {
++ if (!have_node) {
++ have_node = true;
++ node = node_vdso;
++ }
++
++ if (cpu_vdso != cpu) {
++ printf("[FAIL]\tvDSO reported CPU %hu but should be %d\n", cpu_vdso, cpu);
++ nerrs++;
++ } else {
++ printf("[OK]\tvDSO reported correct CPU\n");
++ }
++
++ if (node_vdso != node) {
++ printf("[FAIL]\tvDSO reported node %hu but should be %hu\n", node_vdso, node);
++ nerrs++;
++ } else {
++ printf("[OK]\tvDSO reported correct node\n");
++ }
++ }
++ }
++
++ if (vgetcpu) {
++ if (ret_vsys) {
++ printf("[FAIL]\tvsyscall getcpu() failed\n");
++ nerrs++;
++ } else {
++ if (!have_node) {
++ have_node = true;
++ node = node_vsys;
++ }
++
++ if (cpu_vsys != cpu) {
++ printf("[FAIL]\tvsyscall reported CPU %hu but should be %d\n", cpu_vsys, cpu);
++ nerrs++;
++ } else {
++ printf("[OK]\tvsyscall reported correct CPU\n");
++ }
++
++ if (node_vsys != node) {
++ printf("[FAIL]\tvsyscall reported node %hu but should be %hu\n", node_vsys, node);
++ nerrs++;
++ } else {
++ printf("[OK]\tvsyscall reported correct node\n");
++ }
++ }
++ }
++
++ return nerrs;
++}
++
++static int test_vsys_r(void)
++{
++#ifdef __x86_64__
++ printf("[RUN]\tChecking read access to the vsyscall page\n");
++ bool can_read;
++ if (sigsetjmp(jmpbuf, 1) == 0) {
++ *(volatile int *)0xffffffffff600000;
++ can_read = true;
++ } else {
++ can_read = false;
++ }
++
++ if (can_read && !should_read_vsyscall) {
++ printf("[FAIL]\tWe have read access, but we shouldn't\n");
++ return 1;
++ } else if (!can_read && should_read_vsyscall) {
++ printf("[FAIL]\tWe don't have read access, but we should\n");
++ return 1;
++ } else {
++ printf("[OK]\tgot expected result\n");
++ }
++#endif
++
++ return 0;
++}
++
++
++#ifdef __x86_64__
++#define X86_EFLAGS_TF (1UL << 8)
++static volatile sig_atomic_t num_vsyscall_traps;
++
++static unsigned long get_eflags(void)
++{
++ unsigned long eflags;
++ asm volatile ("pushfq\n\tpopq %0" : "=rm" (eflags));
++ return eflags;
++}
++
++static void set_eflags(unsigned long eflags)
++{
++ asm volatile ("pushq %0\n\tpopfq" : : "rm" (eflags) : "flags");
++}
++
++static void sigtrap(int sig, siginfo_t *info, void *ctx_void)
++{
++ ucontext_t *ctx = (ucontext_t *)ctx_void;
++ unsigned long ip = ctx->uc_mcontext.gregs[REG_RIP];
++
++ if (((ip ^ 0xffffffffff600000UL) & ~0xfffUL) == 0)
++ num_vsyscall_traps++;
++}
++
++static int test_native_vsyscall(void)
++{
++ time_t tmp;
++ bool is_native;
++
++ if (!vtime)
++ return 0;
++
++ printf("[RUN]\tchecking for native vsyscall\n");
++ sethandler(SIGTRAP, sigtrap, 0);
++ set_eflags(get_eflags() | X86_EFLAGS_TF);
++ vtime(&tmp);
++ set_eflags(get_eflags() & ~X86_EFLAGS_TF);
++
++ /*
++ * If vsyscalls are emulated, we expect a single trap in the
++ * vsyscall page -- the call instruction will trap with RIP
++ * pointing to the entry point before emulation takes over.
++ * In native mode, we expect two traps, since whatever code
++ * the vsyscall page contains will be more than just a ret
++ * instruction.
++ */
++ is_native = (num_vsyscall_traps > 1);
++
++ printf("\tvsyscalls are %s (%d instructions in vsyscall page)\n",
++ (is_native ? "native" : "emulated"),
++ (int)num_vsyscall_traps);
++
++ return 0;
++}
++#endif
++
++int main(int argc, char **argv)
++{
++ int nerrs = 0;
++
++ init_vdso();
++ nerrs += init_vsys();
++
++ nerrs += test_gtod();
++ nerrs += test_time();
++ nerrs += test_getcpu(0);
++ nerrs += test_getcpu(1);
++
++ sethandler(SIGSEGV, sigsegv, 0);
++ nerrs += test_vsys_r();
++
++#ifdef __x86_64__
++ nerrs += test_native_vsyscall();
++#endif
++
++ return nerrs ? 1 : 0;
++}
--- /dev/null
+From 61dc0f555b5c761cdafb0ba5bd41ecf22d68a4c4 Mon Sep 17 00:00:00 2001
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Sun, 7 Jan 2018 22:48:01 +0100
+Subject: x86/cpu: Implement CPU vulnerabilites sysfs functions
+
+From: Thomas Gleixner <tglx@linutronix.de>
+
+commit 61dc0f555b5c761cdafb0ba5bd41ecf22d68a4c4 upstream.
+
+Implement the CPU vulnerabilty show functions for meltdown, spectre_v1 and
+spectre_v2.
+
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Cc: Peter Zijlstra <peterz@infradead.org>
+Cc: Will Deacon <will.deacon@arm.com>
+Cc: Dave Hansen <dave.hansen@intel.com>
+Cc: Linus Torvalds <torvalds@linuxfoundation.org>
+Cc: Borislav Petkov <bp@alien8.de>
+Cc: David Woodhouse <dwmw@amazon.co.uk>
+Link: https://lkml.kernel.org/r/20180107214913.177414879@linutronix.de
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/x86/Kconfig | 1 +
+ arch/x86/kernel/cpu/bugs.c | 29 +++++++++++++++++++++++++++++
+ 2 files changed, 30 insertions(+)
+
+--- a/arch/x86/Kconfig
++++ b/arch/x86/Kconfig
+@@ -62,6 +62,7 @@ config X86
+ select GENERIC_CLOCKEVENTS_MIN_ADJUST
+ select GENERIC_CMOS_UPDATE
+ select GENERIC_CPU_AUTOPROBE
++ select GENERIC_CPU_VULNERABILITIES
+ select GENERIC_EARLY_IOREMAP
+ select GENERIC_FIND_FIRST_BIT
+ select GENERIC_IOMAP
+--- a/arch/x86/kernel/cpu/bugs.c
++++ b/arch/x86/kernel/cpu/bugs.c
+@@ -9,6 +9,7 @@
+ */
+ #include <linux/init.h>
+ #include <linux/utsname.h>
++#include <linux/cpu.h>
+ #include <asm/bugs.h>
+ #include <asm/processor.h>
+ #include <asm/processor-flags.h>
+@@ -49,3 +50,31 @@ void __init check_bugs(void)
+
+ fpu__init_check_bugs();
+ }
++
++#ifdef CONFIG_SYSFS
++ssize_t cpu_show_meltdown(struct device *dev,
++ struct device_attribute *attr, char *buf)
++{
++ if (!boot_cpu_has_bug(X86_BUG_CPU_MELTDOWN))
++ return sprintf(buf, "Not affected\n");
++ if (boot_cpu_has(X86_FEATURE_PTI))
++ return sprintf(buf, "Mitigation: PTI\n");
++ return sprintf(buf, "Vulnerable\n");
++}
++
++ssize_t cpu_show_spectre_v1(struct device *dev,
++ struct device_attribute *attr, char *buf)
++{
++ if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V1))
++ return sprintf(buf, "Not affected\n");
++ return sprintf(buf, "Vulnerable\n");
++}
++
++ssize_t cpu_show_spectre_v2(struct device *dev,
++ struct device_attribute *attr, char *buf)
++{
++ if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
++ return sprintf(buf, "Not affected\n");
++ return sprintf(buf, "Vulnerable\n");
++}
++#endif
projects / thirdparty / kernel / stable-queue.git / commitdiff
