diff options
Diffstat (limited to 'tools/testing/selftests/x86')
| -rw-r--r-- | tools/testing/selftests/x86/Makefile | 55 | ||||
| -rwxr-xr-x | tools/testing/selftests/x86/check_cc.sh | 16 | ||||
| -rw-r--r-- | tools/testing/selftests/x86/run_x86_tests.sh | 11 | ||||
| -rw-r--r-- | tools/testing/selftests/x86/single_step_syscall.c | 181 | ||||
| -rw-r--r-- | tools/testing/selftests/x86/trivial_32bit_program.c | 4 | ||||
| -rw-r--r-- | tools/testing/selftests/x86/trivial_64bit_program.c | 18 |
6 files changed, 251 insertions, 34 deletions
diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index f0a7918178dd..5bdb781163d1 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -1,48 +1,57 @@ -.PHONY: all all_32 all_64 check_build32 clean run_tests +all: -TARGETS_C_BOTHBITS := sigreturn +include ../lib.mk + +.PHONY: all all_32 all_64 warn_32bit_failure clean + +TARGETS_C_BOTHBITS := sigreturn single_step_syscall BINARIES_32 := $(TARGETS_C_BOTHBITS:%=%_32) BINARIES_64 := $(TARGETS_C_BOTHBITS:%=%_64) CFLAGS := -O2 -g -std=gnu99 -pthread -Wall -UNAME_P := $(shell uname -p) +UNAME_M := $(shell uname -m) +CAN_BUILD_I386 := $(shell ./check_cc.sh $(CC) trivial_32bit_program.c -m32) +CAN_BUILD_X86_64 := $(shell ./check_cc.sh $(CC) trivial_64bit_program.c) -# Always build 32-bit tests +ifeq ($(CAN_BUILD_I386),1) all: all_32 +TEST_PROGS += $(BINARIES_32) +endif -# If we're on a 64-bit host, build 64-bit tests as well -ifeq ($(shell uname -p),x86_64) +ifeq ($(CAN_BUILD_X86_64),1) all: all_64 +TEST_PROGS += $(BINARIES_64) endif -all_32: check_build32 $(BINARIES_32) +all_32: $(BINARIES_32) all_64: $(BINARIES_64) clean: $(RM) $(BINARIES_32) $(BINARIES_64) -run_tests: - ./run_x86_tests.sh - $(TARGETS_C_BOTHBITS:%=%_32): %_32: %.c $(CC) -m32 -o $@ $(CFLAGS) $(EXTRA_CFLAGS) $^ -lrt -ldl $(TARGETS_C_BOTHBITS:%=%_64): %_64: %.c $(CC) -m64 -o $@ $(CFLAGS) $(EXTRA_CFLAGS) $^ -lrt -ldl -check_build32: - @if ! $(CC) -m32 -o /dev/null trivial_32bit_program.c; then \ - echo "Warning: you seem to have a broken 32-bit build" 2>&1; \ - echo "environment. If you are using a Debian-like"; \ - echo " distribution, try:"; \ - echo ""; \ - echo " apt-get install gcc-multilib libc6-i386 libc6-dev-i386"; \ - echo ""; \ - echo "If you are using a Fedora-like distribution, try:"; \ - echo ""; \ - echo " yum install glibc-devel.*i686"; \ - exit 1; \ - fi +# x86_64 users should be encouraged to install 32-bit libraries +ifeq ($(CAN_BUILD_I386)$(CAN_BUILD_X86_64),01) +all: warn_32bit_failure + +warn_32bit_failure: + @echo "Warning: you seem to have a broken 32-bit build" 2>&1; \ + echo "environment. This will reduce test coverage of 64-bit" 2>&1; \ + echo "kernels. If you are using a Debian-like distribution," 2>&1; \ + echo "try:"; 2>&1; \ + echo ""; \ + echo " apt-get install gcc-multilib libc6-i386 libc6-dev-i386"; \ + echo ""; \ + echo "If you are using a Fedora-like distribution, try:"; \ + echo ""; \ + echo " yum install glibc-devel.*i686"; \ + exit 0; +endif diff --git a/tools/testing/selftests/x86/check_cc.sh b/tools/testing/selftests/x86/check_cc.sh new file mode 100755 index 000000000000..172d3293fb7b --- /dev/null +++ b/tools/testing/selftests/x86/check_cc.sh @@ -0,0 +1,16 @@ +#!/bin/sh +# check_cc.sh - Helper to test userspace compilation support +# Copyright (c) 2015 Andrew Lutomirski +# GPL v2 + +CC="$1" +TESTPROG="$2" +shift 2 + +if "$CC" -o /dev/null "$TESTPROG" -O0 "$@" 2>/dev/null; then + echo 1 +else + echo 0 +fi + +exit 0 diff --git a/tools/testing/selftests/x86/run_x86_tests.sh b/tools/testing/selftests/x86/run_x86_tests.sh deleted file mode 100644 index 3d3ec65f3e7c..000000000000 --- a/tools/testing/selftests/x86/run_x86_tests.sh +++ /dev/null @@ -1,11 +0,0 @@ -#!/bin/bash - -# This is deliberately minimal. IMO kselftests should provide a standard -# script here. -./sigreturn_32 || exit 1 - -if [[ "$uname -p" -eq "x86_64" ]]; then - ./sigreturn_64 || exit 1 -fi - -exit 0 diff --git a/tools/testing/selftests/x86/single_step_syscall.c b/tools/testing/selftests/x86/single_step_syscall.c new file mode 100644 index 000000000000..50c26358e8b7 --- /dev/null +++ b/tools/testing/selftests/x86/single_step_syscall.c @@ -0,0 +1,181 @@ +/* + * single_step_syscall.c - single-steps various x86 syscalls + * Copyright (c) 2014-2015 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 is a very simple series of tests that makes system calls with + * the TF flag set. This exercises some nasty kernel code in the + * SYSENTER case: SYSENTER does not clear TF, so SYSENTER with TF set + * immediately issues #DB from CPL 0. This requires special handling in + * the kernel. + */ + +#define _GNU_SOURCE + +#include <sys/time.h> +#include <time.h> +#include <stdlib.h> +#include <sys/syscall.h> +#include <unistd.h> +#include <stdio.h> +#include <string.h> +#include <inttypes.h> +#include <sys/mman.h> +#include <sys/signal.h> +#include <sys/ucontext.h> +#include <asm/ldt.h> +#include <err.h> +#include <setjmp.h> +#include <stddef.h> +#include <stdbool.h> +#include <sys/ptrace.h> +#include <sys/user.h> + +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"); +} + +static volatile sig_atomic_t sig_traps; + +#ifdef __x86_64__ +# define REG_IP REG_RIP +# define WIDTH "q" +#else +# define REG_IP REG_EIP +# define WIDTH "l" +#endif + +static unsigned long get_eflags(void) +{ + unsigned long eflags; + asm volatile ("pushf" WIDTH "\n\tpop" WIDTH " %0" : "=rm" (eflags)); + return eflags; +} + +static void set_eflags(unsigned long eflags) +{ + asm volatile ("push" WIDTH " %0\n\tpopf" WIDTH + : : "rm" (eflags) : "flags"); +} + +#define X86_EFLAGS_TF (1UL << 8) + +static void sigtrap(int sig, siginfo_t *info, void *ctx_void) +{ + ucontext_t *ctx = (ucontext_t*)ctx_void; + + if (get_eflags() & X86_EFLAGS_TF) { + set_eflags(get_eflags() & ~X86_EFLAGS_TF); + printf("[WARN]\tSIGTRAP handler had TF set\n"); + _exit(1); + } + + sig_traps++; + + if (sig_traps == 10000 || sig_traps == 10001) { + printf("[WARN]\tHit %d SIGTRAPs with si_addr 0x%lx, ip 0x%lx\n", + (int)sig_traps, + (unsigned long)info->si_addr, + (unsigned long)ctx->uc_mcontext.gregs[REG_IP]); + } +} + +static void check_result(void) +{ + unsigned long new_eflags = get_eflags(); + set_eflags(new_eflags & ~X86_EFLAGS_TF); + + if (!sig_traps) { + printf("[FAIL]\tNo SIGTRAP\n"); + exit(1); + } + + if (!(new_eflags & X86_EFLAGS_TF)) { + printf("[FAIL]\tTF was cleared\n"); + exit(1); + } + + printf("[OK]\tSurvived with TF set and %d traps\n", (int)sig_traps); + sig_traps = 0; +} + +int main() +{ + int tmp; + + sethandler(SIGTRAP, sigtrap, 0); + + printf("[RUN]\tSet TF and check nop\n"); + set_eflags(get_eflags() | X86_EFLAGS_TF); + asm volatile ("nop"); + check_result(); + +#ifdef __x86_64__ + printf("[RUN]\tSet TF and check syscall-less opportunistic sysret\n"); + set_eflags(get_eflags() | X86_EFLAGS_TF); + extern unsigned char post_nop[]; + asm volatile ("pushf" WIDTH "\n\t" + "pop" WIDTH " %%r11\n\t" + "nop\n\t" + "post_nop:" + : : "c" (post_nop) : "r11"); + check_result(); +#endif + + printf("[RUN]\tSet TF and check int80\n"); + set_eflags(get_eflags() | X86_EFLAGS_TF); + asm volatile ("int $0x80" : "=a" (tmp) : "a" (SYS_getpid)); + check_result(); + + /* + * This test is particularly interesting if fast syscalls use + * SYSENTER: it triggers a nasty design flaw in SYSENTER. + * Specifically, SYSENTER does not clear TF, so either SYSENTER + * or the next instruction traps at CPL0. (Of course, Intel + * mostly forgot to document exactly what happens here.) So we + * get a CPL0 fault with usergs (on 64-bit kernels) and possibly + * no stack. The only sane way the kernel can possibly handle + * it is to clear TF on return from the #DB handler, but this + * happens way too early to set TF in the saved pt_regs, so the + * kernel has to do something clever to avoid losing track of + * the TF bit. + * + * Needless to say, we've had bugs in this area. + */ + syscall(SYS_getpid); /* Force symbol binding without TF set. */ + printf("[RUN]\tSet TF and check a fast syscall\n"); + set_eflags(get_eflags() | X86_EFLAGS_TF); + syscall(SYS_getpid); + check_result(); + + /* Now make sure that another fast syscall doesn't set TF again. */ + printf("[RUN]\tFast syscall with TF cleared\n"); + fflush(stdout); /* Force a syscall */ + if (get_eflags() & X86_EFLAGS_TF) { + printf("[FAIL]\tTF is now set\n"); + exit(1); + } + if (sig_traps) { + printf("[FAIL]\tGot SIGTRAP\n"); + exit(1); + } + printf("[OK]\tNothing unexpected happened\n"); + + return 0; +} diff --git a/tools/testing/selftests/x86/trivial_32bit_program.c b/tools/testing/selftests/x86/trivial_32bit_program.c index 2e231beb0a39..fabdf0f51621 100644 --- a/tools/testing/selftests/x86/trivial_32bit_program.c +++ b/tools/testing/selftests/x86/trivial_32bit_program.c @@ -4,6 +4,10 @@ * GPL v2 */ +#ifndef __i386__ +# error wrong architecture +#endif + #include <stdio.h> int main() diff --git a/tools/testing/selftests/x86/trivial_64bit_program.c b/tools/testing/selftests/x86/trivial_64bit_program.c new file mode 100644 index 000000000000..b994946c40fb --- /dev/null +++ b/tools/testing/selftests/x86/trivial_64bit_program.c @@ -0,0 +1,18 @@ +/* + * Trivial program to check that we have a valid 32-bit build environment. + * Copyright (c) 2015 Andy Lutomirski + * GPL v2 + */ + +#ifndef __x86_64__ +# error wrong architecture +#endif + +#include <stdio.h> + +int main() +{ + printf("\n"); + + return 0; +} |
