aboutsummaryrefslogtreecommitdiffstats
path: root/tools
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2015-09-01 08:40:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-01 08:40:25 -0700
commit5778077d03cb25aac9b6a428e18970642fc019e3 (patch)
tree2e3f3da1fb99c3646da5ed9a09644696ca5f2309 /tools
parent65a99597f044c083983f4274ab049c9ec3b9d764 (diff)
parent7e01ebffffedec22cea86ebe94802f909e4579ca (diff)
Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm changes from Ingo Molnar: "The biggest changes in this cycle were: - Revamp, simplify (and in some cases fix) Time Stamp Counter (TSC) primitives. (Andy Lutomirski) - Add new, comprehensible entry and exit handlers written in C. (Andy Lutomirski) - vm86 mode cleanups and fixes. (Brian Gerst) - 32-bit compat code cleanups. (Brian Gerst) The amount of simplification in low level assembly code is already palpable: arch/x86/entry/entry_32.S | 130 +---- arch/x86/entry/entry_64.S | 197 ++----- but more simplifications are planned. There's also the usual laudry mix of low level changes - see the changelog for details" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (83 commits) x86/asm: Drop repeated macro of X86_EFLAGS_AC definition x86/asm/msr: Make wrmsrl() a function x86/asm/delay: Introduce an MWAITX-based delay with a configurable timer x86/asm: Add MONITORX/MWAITX instruction support x86/traps: Weaken context tracking entry assertions x86/asm/tsc: Add rdtscll() merge helper selftests/x86: Add syscall_nt selftest selftests/x86: Disable sigreturn_64 x86/vdso: Emit a GNU hash x86/entry: Remove do_notify_resume(), syscall_trace_leave(), and their TIF masks x86/entry/32: Migrate to C exit path x86/entry/32: Remove 32-bit syscall audit optimizations x86/vm86: Rename vm86->v86flags and v86mask x86/vm86: Rename vm86->vm86_info to user_vm86 x86/vm86: Clean up vm86.h includes x86/vm86: Move the vm86 IRQ definitions to vm86.h x86/vm86: Use the normal pt_regs area for vm86 x86/vm86: Eliminate 'struct kernel_vm86_struct' x86/vm86: Move fields from 'struct kernel_vm86_struct' to 'struct vm86' x86/vm86: Move vm86 fields out of 'thread_struct' ...
Diffstat (limited to 'tools')
-rw-r--r--tools/power/cpupower/debug/kernel/cpufreq-test_tsc.c4
-rw-r--r--tools/testing/selftests/x86/Makefile4
-rw-r--r--tools/testing/selftests/x86/entry_from_vm86.c139
-rw-r--r--tools/testing/selftests/x86/ldt_gdt.c576
-rw-r--r--tools/testing/selftests/x86/syscall_arg_fault.c130
-rw-r--r--tools/testing/selftests/x86/syscall_nt.c54
6 files changed, 893 insertions, 14 deletions
diff --git a/tools/power/cpupower/debug/kernel/cpufreq-test_tsc.c b/tools/power/cpupower/debug/kernel/cpufreq-test_tsc.c
index 5224ee5b392d..6ff8383f2941 100644
--- a/tools/power/cpupower/debug/kernel/cpufreq-test_tsc.c
+++ b/tools/power/cpupower/debug/kernel/cpufreq-test_tsc.c
@@ -81,11 +81,11 @@ static int __init cpufreq_test_tsc(void)
printk(KERN_DEBUG "start--> \n");
then = read_pmtmr();
- rdtscll(then_tsc);
+ then_tsc = rdtsc();
for (i=0;i<20;i++) {
mdelay(100);
now = read_pmtmr();
- rdtscll(now_tsc);
+ now_tsc = rdtsc();
diff = (now - then) & 0xFFFFFF;
diff_tsc = now_tsc - then_tsc;
printk(KERN_DEBUG "t1: %08u t2: %08u diff_pmtmr: %08u diff_tsc: %016llu\n", then, now, diff, diff_tsc);
diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile
index caa60d56d7d1..29089b24d18b 100644
--- a/tools/testing/selftests/x86/Makefile
+++ b/tools/testing/selftests/x86/Makefile
@@ -4,8 +4,8 @@ include ../lib.mk
.PHONY: all all_32 all_64 warn_32bit_failure clean
-TARGETS_C_BOTHBITS := sigreturn single_step_syscall sysret_ss_attrs
-TARGETS_C_32BIT_ONLY := entry_from_vm86
+TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs ldt_gdt syscall_nt
+TARGETS_C_32BIT_ONLY := entry_from_vm86 syscall_arg_fault sigreturn
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/entry_from_vm86.c b/tools/testing/selftests/x86/entry_from_vm86.c
index 5c38a187677b..9a43a59a9bb4 100644
--- a/tools/testing/selftests/x86/entry_from_vm86.c
+++ b/tools/testing/selftests/x86/entry_from_vm86.c
@@ -28,6 +28,55 @@
static unsigned long load_addr = 0x10000;
static int nerrs = 0;
+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 void clearhandler(int sig)
+{
+ struct sigaction sa;
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_handler = SIG_DFL;
+ sigemptyset(&sa.sa_mask);
+ if (sigaction(sig, &sa, 0))
+ err(1, "sigaction");
+}
+
+static sig_atomic_t got_signal;
+
+static void sighandler(int sig, siginfo_t *info, void *ctx_void)
+{
+ ucontext_t *ctx = (ucontext_t*)ctx_void;
+
+ if (ctx->uc_mcontext.gregs[REG_EFL] & X86_EFLAGS_VM ||
+ (ctx->uc_mcontext.gregs[REG_CS] & 3) != 3) {
+ printf("[FAIL]\tSignal frame should not reflect vm86 mode\n");
+ nerrs++;
+ }
+
+ const char *signame;
+ if (sig == SIGSEGV)
+ signame = "SIGSEGV";
+ else if (sig == SIGILL)
+ signame = "SIGILL";
+ else
+ signame = "unexpected signal";
+
+ printf("[INFO]\t%s: FLAGS = 0x%lx, CS = 0x%hx\n", signame,
+ (unsigned long)ctx->uc_mcontext.gregs[REG_EFL],
+ (unsigned short)ctx->uc_mcontext.gregs[REG_CS]);
+
+ got_signal = 1;
+}
+
asm (
".pushsection .rodata\n\t"
".type vmcode_bound, @object\n\t"
@@ -38,6 +87,14 @@ asm (
"int3\n\t"
"vmcode_sysenter:\n\t"
"sysenter\n\t"
+ "vmcode_syscall:\n\t"
+ "syscall\n\t"
+ "vmcode_sti:\n\t"
+ "sti\n\t"
+ "vmcode_int3:\n\t"
+ "int3\n\t"
+ "vmcode_int80:\n\t"
+ "int $0x80\n\t"
".size vmcode, . - vmcode\n\t"
"end_vmcode:\n\t"
".code32\n\t"
@@ -45,9 +102,12 @@ asm (
);
extern unsigned char vmcode[], end_vmcode[];
-extern unsigned char vmcode_bound[], vmcode_sysenter[];
+extern unsigned char vmcode_bound[], vmcode_sysenter[], vmcode_syscall[],
+ vmcode_sti[], vmcode_int3[], vmcode_int80[];
-static void do_test(struct vm86plus_struct *v86, unsigned long eip,
+/* Returns false if the test was skipped. */
+static bool do_test(struct vm86plus_struct *v86, unsigned long eip,
+ unsigned int rettype, unsigned int retarg,
const char *text)
{
long ret;
@@ -58,7 +118,7 @@ static void do_test(struct vm86plus_struct *v86, unsigned long eip,
if (ret == -1 && errno == ENOSYS) {
printf("[SKIP]\tvm86 not supported\n");
- return;
+ return false;
}
if (VM86_TYPE(ret) == VM86_INTx) {
@@ -73,13 +133,30 @@ static void do_test(struct vm86plus_struct *v86, unsigned long eip,
else
sprintf(trapname, "%d", trapno);
- printf("[OK]\tExited vm86 mode due to #%s\n", trapname);
+ printf("[INFO]\tExited vm86 mode due to #%s\n", trapname);
} else if (VM86_TYPE(ret) == VM86_UNKNOWN) {
- printf("[OK]\tExited vm86 mode due to unhandled GP fault\n");
+ printf("[INFO]\tExited vm86 mode due to unhandled GP fault\n");
+ } else if (VM86_TYPE(ret) == VM86_TRAP) {
+ printf("[INFO]\tExited vm86 mode due to a trap (arg=%ld)\n",
+ VM86_ARG(ret));
+ } else if (VM86_TYPE(ret) == VM86_SIGNAL) {
+ printf("[INFO]\tExited vm86 mode due to a signal\n");
+ } else if (VM86_TYPE(ret) == VM86_STI) {
+ printf("[INFO]\tExited vm86 mode due to STI\n");
} else {
- printf("[OK]\tExited vm86 mode due to type %ld, arg %ld\n",
+ printf("[INFO]\tExited vm86 mode due to type %ld, arg %ld\n",
VM86_TYPE(ret), VM86_ARG(ret));
}
+
+ if (rettype == -1 ||
+ (VM86_TYPE(ret) == rettype && VM86_ARG(ret) == retarg)) {
+ printf("[OK]\tReturned correctly\n");
+ } else {
+ printf("[FAIL]\tIncorrect return reason\n");
+ nerrs++;
+ }
+
+ return true;
}
int main(void)
@@ -105,10 +182,52 @@ int main(void)
assert((v86.regs.cs & 3) == 0); /* Looks like RPL = 0 */
/* #BR -- should deliver SIG??? */
- do_test(&v86, vmcode_bound - vmcode, "#BR");
-
- /* SYSENTER -- should cause #GP or #UD depending on CPU */
- do_test(&v86, vmcode_sysenter - vmcode, "SYSENTER");
+ do_test(&v86, vmcode_bound - vmcode, VM86_INTx, 5, "#BR");
+
+ /*
+ * SYSENTER -- should cause #GP or #UD depending on CPU.
+ * Expected return type -1 means that we shouldn't validate
+ * the vm86 return value. This will avoid problems on non-SEP
+ * CPUs.
+ */
+ sethandler(SIGILL, sighandler, 0);
+ do_test(&v86, vmcode_sysenter - vmcode, -1, 0, "SYSENTER");
+ clearhandler(SIGILL);
+
+ /*
+ * SYSCALL would be a disaster in VM86 mode. Fortunately,
+ * there is no kernel that both enables SYSCALL and sets
+ * EFER.SCE, so it's #UD on all systems. But vm86 is
+ * buggy (or has a "feature"), so the SIGILL will actually
+ * be delivered.
+ */
+ sethandler(SIGILL, sighandler, 0);
+ do_test(&v86, vmcode_syscall - vmcode, VM86_SIGNAL, 0, "SYSCALL");
+ clearhandler(SIGILL);
+
+ /* STI with VIP set */
+ v86.regs.eflags |= X86_EFLAGS_VIP;
+ v86.regs.eflags &= ~X86_EFLAGS_IF;
+ do_test(&v86, vmcode_sti - vmcode, VM86_STI, 0, "STI with VIP set");
+
+ /* INT3 -- should cause #BP */
+ do_test(&v86, vmcode_int3 - vmcode, VM86_TRAP, 3, "INT3");
+
+ /* INT80 -- should exit with "INTx 0x80" */
+ v86.regs.eax = (unsigned int)-1;
+ do_test(&v86, vmcode_int80 - vmcode, VM86_INTx, 0x80, "int80");
+
+ /* Execute a null pointer */
+ v86.regs.cs = 0;
+ v86.regs.ss = 0;
+ sethandler(SIGSEGV, sighandler, 0);
+ got_signal = 0;
+ if (do_test(&v86, 0, VM86_SIGNAL, 0, "Execute null pointer") &&
+ !got_signal) {
+ printf("[FAIL]\tDid not receive SIGSEGV\n");
+ nerrs++;
+ }
+ clearhandler(SIGSEGV);
return (nerrs == 0 ? 0 : 1);
}
diff --git a/tools/testing/selftests/x86/ldt_gdt.c b/tools/testing/selftests/x86/ldt_gdt.c
new file mode 100644
index 000000000000..31a3035cd4eb
--- /dev/null
+++ b/tools/testing/selftests/x86/ldt_gdt.c
@@ -0,0 +1,576 @@
+/*
+ * ldt_gdt.c - Test cases for LDT and GDT access
+ * Copyright (c) 2015 Andrew Lutomirski
+ */
+
+#define _GNU_SOURCE
+#include <err.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <signal.h>
+#include <setjmp.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <asm/ldt.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <stdbool.h>
+#include <pthread.h>
+#include <sched.h>
+#include <linux/futex.h>
+
+#define AR_ACCESSED (1<<8)
+
+#define AR_TYPE_RODATA (0 * (1<<9))
+#define AR_TYPE_RWDATA (1 * (1<<9))
+#define AR_TYPE_RODATA_EXPDOWN (2 * (1<<9))
+#define AR_TYPE_RWDATA_EXPDOWN (3 * (1<<9))
+#define AR_TYPE_XOCODE (4 * (1<<9))
+#define AR_TYPE_XRCODE (5 * (1<<9))
+#define AR_TYPE_XOCODE_CONF (6 * (1<<9))
+#define AR_TYPE_XRCODE_CONF (7 * (1<<9))
+
+#define AR_DPL3 (3 * (1<<13))
+
+#define AR_S (1 << 12)
+#define AR_P (1 << 15)
+#define AR_AVL (1 << 20)
+#define AR_L (1 << 21)
+#define AR_DB (1 << 22)
+#define AR_G (1 << 23)
+
+static int nerrs;
+
+static void check_invalid_segment(uint16_t index, int ldt)
+{
+ uint32_t has_limit = 0, has_ar = 0, limit, ar;
+ uint32_t selector = (index << 3) | (ldt << 2) | 3;
+
+ asm ("lsl %[selector], %[limit]\n\t"
+ "jnz 1f\n\t"
+ "movl $1, %[has_limit]\n\t"
+ "1:"
+ : [limit] "=r" (limit), [has_limit] "+rm" (has_limit)
+ : [selector] "r" (selector));
+ asm ("larl %[selector], %[ar]\n\t"
+ "jnz 1f\n\t"
+ "movl $1, %[has_ar]\n\t"
+ "1:"
+ : [ar] "=r" (ar), [has_ar] "+rm" (has_ar)
+ : [selector] "r" (selector));
+
+ if (has_limit || has_ar) {
+ printf("[FAIL]\t%s entry %hu is valid but should be invalid\n",
+ (ldt ? "LDT" : "GDT"), index);
+ nerrs++;
+ } else {
+ printf("[OK]\t%s entry %hu is invalid\n",
+ (ldt ? "LDT" : "GDT"), index);
+ }
+}
+
+static void check_valid_segment(uint16_t index, int ldt,
+ uint32_t expected_ar, uint32_t expected_limit,
+ bool verbose)
+{
+ uint32_t has_limit = 0, has_ar = 0, limit, ar;
+ uint32_t selector = (index << 3) | (ldt << 2) | 3;
+
+ asm ("lsl %[selector], %[limit]\n\t"
+ "jnz 1f\n\t"
+ "movl $1, %[has_limit]\n\t"
+ "1:"
+ : [limit] "=r" (limit), [has_limit] "+rm" (has_limit)
+ : [selector] "r" (selector));
+ asm ("larl %[selector], %[ar]\n\t"
+ "jnz 1f\n\t"
+ "movl $1, %[has_ar]\n\t"
+ "1:"
+ : [ar] "=r" (ar), [has_ar] "+rm" (has_ar)
+ : [selector] "r" (selector));
+
+ if (!has_limit || !has_ar) {
+ printf("[FAIL]\t%s entry %hu is invalid but should be valid\n",
+ (ldt ? "LDT" : "GDT"), index);
+ nerrs++;
+ return;
+ }
+
+ if (ar != expected_ar) {
+ printf("[FAIL]\t%s entry %hu has AR 0x%08X but expected 0x%08X\n",
+ (ldt ? "LDT" : "GDT"), index, ar, expected_ar);
+ nerrs++;
+ } else if (limit != expected_limit) {
+ printf("[FAIL]\t%s entry %hu has limit 0x%08X but expected 0x%08X\n",
+ (ldt ? "LDT" : "GDT"), index, limit, expected_limit);
+ nerrs++;
+ } else if (verbose) {
+ printf("[OK]\t%s entry %hu has AR 0x%08X and limit 0x%08X\n",
+ (ldt ? "LDT" : "GDT"), index, ar, limit);
+ }
+}
+
+static bool install_valid_mode(const struct user_desc *desc, uint32_t ar,
+ bool oldmode)
+{
+ int ret = syscall(SYS_modify_ldt, oldmode ? 1 : 0x11,
+ desc, sizeof(*desc));
+ if (ret < -1)
+ errno = -ret;
+ if (ret == 0) {
+ uint32_t limit = desc->limit;
+ if (desc->limit_in_pages)
+ limit = (limit << 12) + 4095;
+ check_valid_segment(desc->entry_number, 1, ar, limit, true);
+ return true;
+ } else if (errno == ENOSYS) {
+ printf("[OK]\tmodify_ldt returned -ENOSYS\n");
+ return false;
+ } else {
+ if (desc->seg_32bit) {
+ printf("[FAIL]\tUnexpected modify_ldt failure %d\n",
+ errno);
+ nerrs++;
+ return false;
+ } else {
+ printf("[OK]\tmodify_ldt rejected 16 bit segment\n");
+ return false;
+ }
+ }
+}
+
+static bool install_valid(const struct user_desc *desc, uint32_t ar)
+{
+ return install_valid_mode(desc, ar, false);
+}
+
+static void install_invalid(const struct user_desc *desc, bool oldmode)
+{
+ int ret = syscall(SYS_modify_ldt, oldmode ? 1 : 0x11,
+ desc, sizeof(*desc));
+ if (ret < -1)
+ errno = -ret;
+ if (ret == 0) {
+ check_invalid_segment(desc->entry_number, 1);
+ } else if (errno == ENOSYS) {
+ printf("[OK]\tmodify_ldt returned -ENOSYS\n");
+ } else {
+ if (desc->seg_32bit) {
+ printf("[FAIL]\tUnexpected modify_ldt failure %d\n",
+ errno);
+ nerrs++;
+ } else {
+ printf("[OK]\tmodify_ldt rejected 16 bit segment\n");
+ }
+ }
+}
+
+static int safe_modify_ldt(int func, struct user_desc *ptr,
+ unsigned long bytecount)
+{
+ int ret = syscall(SYS_modify_ldt, 0x11, ptr, bytecount);
+ if (ret < -1)
+ errno = -ret;
+ return ret;
+}
+
+static void fail_install(struct user_desc *desc)
+{
+ if (safe_modify_ldt(0x11, desc, sizeof(*desc)) == 0) {
+ printf("[FAIL]\tmodify_ldt accepted a bad descriptor\n");
+ nerrs++;
+ } else if (errno == ENOSYS) {
+ printf("[OK]\tmodify_ldt returned -ENOSYS\n");
+ } else {
+ printf("[OK]\tmodify_ldt failure %d\n", errno);
+ }
+}
+
+static void do_simple_tests(void)
+{
+ struct user_desc desc = {
+ .entry_number = 0,
+ .base_addr = 0,
+ .limit = 10,
+ .seg_32bit = 1,
+ .contents = 2, /* Code, not conforming */
+ .read_exec_only = 0,
+ .limit_in_pages = 0,
+ .seg_not_present = 0,
+ .useable = 0
+ };
+ install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE | AR_S | AR_P | AR_DB);
+
+ desc.limit_in_pages = 1;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE |
+ AR_S | AR_P | AR_DB | AR_G);
+
+ check_invalid_segment(1, 1);
+
+ desc.entry_number = 2;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE |
+ AR_S | AR_P | AR_DB | AR_G);
+
+ check_invalid_segment(1, 1);
+
+ desc.base_addr = 0xf0000000;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE |
+ AR_S | AR_P | AR_DB | AR_G);
+
+ desc.useable = 1;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE |
+ AR_S | AR_P | AR_DB | AR_G | AR_AVL);
+
+ desc.seg_not_present = 1;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE |
+ AR_S | AR_DB | AR_G | AR_AVL);
+
+ desc.seg_32bit = 0;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE |
+ AR_S | AR_G | AR_AVL);
+
+ desc.seg_32bit = 1;
+ desc.contents = 0;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA |
+ AR_S | AR_DB | AR_G | AR_AVL);
+
+ desc.read_exec_only = 1;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA |
+ AR_S | AR_DB | AR_G | AR_AVL);
+
+ desc.contents = 1;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA_EXPDOWN |
+ AR_S | AR_DB | AR_G | AR_AVL);
+
+ desc.read_exec_only = 0;
+ desc.limit_in_pages = 0;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA_EXPDOWN |
+ AR_S | AR_DB | AR_AVL);
+
+ desc.contents = 3;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE_CONF |
+ AR_S | AR_DB | AR_AVL);
+
+ desc.read_exec_only = 1;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_XOCODE_CONF |
+ AR_S | AR_DB | AR_AVL);
+
+ desc.read_exec_only = 0;
+ desc.contents = 2;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE |
+ AR_S | AR_DB | AR_AVL);
+
+ desc.read_exec_only = 1;
+
+#ifdef __x86_64__
+ desc.lm = 1;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_XOCODE |
+ AR_S | AR_DB | AR_AVL);
+ desc.lm = 0;
+#endif
+
+ bool entry1_okay = install_valid(&desc, AR_DPL3 | AR_TYPE_XOCODE |
+ AR_S | AR_DB | AR_AVL);
+
+ if (entry1_okay) {
+ printf("[RUN]\tTest fork\n");
+ pid_t child = fork();
+ if (child == 0) {
+ nerrs = 0;
+ check_valid_segment(desc.entry_number, 1,
+ AR_DPL3 | AR_TYPE_XOCODE |
+ AR_S | AR_DB | AR_AVL, desc.limit,
+ true);
+ check_invalid_segment(1, 1);
+ exit(nerrs ? 1 : 0);
+ } else {
+ int status;
+ if (waitpid(child, &status, 0) != child ||
+ !WIFEXITED(status)) {
+ printf("[FAIL]\tChild died\n");
+ nerrs++;
+ } else if (WEXITSTATUS(status) != 0) {
+ printf("[FAIL]\tChild failed\n");
+ nerrs++;
+ } else {
+ printf("[OK]\tChild succeeded\n");
+ }
+ }
+
+ printf("[RUN]\tTest size\n");
+ int i;
+ for (i = 0; i < 8192; i++) {
+ desc.entry_number = i;
+ desc.limit = i;
+ if (safe_modify_ldt(0x11, &desc, sizeof(desc)) != 0) {
+ printf("[FAIL]\tFailed to install entry %d\n", i);
+ nerrs++;
+ break;
+ }
+ }
+ for (int j = 0; j < i; j++) {
+ check_valid_segment(j, 1, AR_DPL3 | AR_TYPE_XOCODE |
+ AR_S | AR_DB | AR_AVL, j, false);
+ }
+ printf("[DONE]\tSize test\n");
+ } else {
+ printf("[SKIP]\tSkipping fork and size tests because we have no LDT\n");
+ }
+
+ /* Test entry_number too high. */
+ desc.entry_number = 8192;
+ fail_install(&desc);
+
+ /* Test deletion and actions mistakeable for deletion. */
+ memset(&desc, 0, sizeof(desc));
+ install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S | AR_P);
+
+ desc.seg_not_present = 1;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S);
+
+ desc.seg_not_present = 0;
+ desc.read_exec_only = 1;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA | AR_S | AR_P);
+
+ desc.read_exec_only = 0;
+ desc.seg_not_present = 1;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S);
+
+ desc.read_exec_only = 1;
+ desc.limit = 1;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA | AR_S);
+
+ desc.limit = 0;
+ desc.base_addr = 1;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA | AR_S);
+
+ desc.base_addr = 0;
+ install_invalid(&desc, false);
+
+ desc.seg_not_present = 0;
+ desc.read_exec_only = 0;
+ desc.seg_32bit = 1;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S | AR_P | AR_DB);
+ install_invalid(&desc, true);
+}
+
+/*
+ * 0: thread is idle
+ * 1: thread armed
+ * 2: thread should clear LDT entry 0
+ * 3: thread should exit
+ */
+static volatile unsigned int ftx;
+
+static void *threadproc(void *ctx)
+{
+ cpu_set_t cpuset;
+ CPU_ZERO(&cpuset);
+ CPU_SET(1, &cpuset);
+ if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0)
+ err(1, "sched_setaffinity to CPU 1"); /* should never fail */
+
+ while (1) {
+ syscall(SYS_futex, &ftx, FUTEX_WAIT, 0, NULL, NULL, 0);
+ while (ftx != 2) {
+ if (ftx >= 3)
+ return NULL;
+ }
+
+ /* clear LDT entry 0 */
+ const struct user_desc desc = {};
+ if (syscall(SYS_modify_ldt, 1, &desc, sizeof(desc)) != 0)
+ err(1, "modify_ldt");
+
+ /* If ftx == 2, set it to zero. If ftx == 100, quit. */
+ unsigned int x = -2;
+ asm volatile ("lock xaddl %[x], %[ftx]" :
+ [x] "+r" (x), [ftx] "+m" (ftx));
+ if (x != 2)
+ return NULL;
+ }
+}
+
+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 jmp_buf jmpbuf;
+
+static void sigsegv(int sig, siginfo_t *info, void *ctx_void)
+{
+ siglongjmp(jmpbuf, 1);
+}
+
+static void do_multicpu_tests(void)
+{
+ cpu_set_t cpuset;
+ pthread_t thread;
+ int failures = 0, iters = 5, i;
+ unsigned short orig_ss;
+
+ CPU_ZERO(&cpuset);
+ CPU_SET(1, &cpuset);
+ if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) {
+ printf("[SKIP]\tCannot set affinity to CPU 1\n");
+ return;
+ }
+
+ CPU_ZERO(&cpuset);
+ CPU_SET(0, &cpuset);
+ if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) {
+ printf("[SKIP]\tCannot set affinity to CPU 0\n");
+ return;
+ }
+
+ sethandler(SIGSEGV, sigsegv, 0);
+#ifdef __i386__
+ /* True 32-bit kernels send SIGILL instead of SIGSEGV on IRET faults. */
+ sethandler(SIGILL, sigsegv, 0);
+#endif
+
+ printf("[RUN]\tCross-CPU LDT invalidation\n");
+
+ if (pthread_create(&thread, 0, threadproc, 0) != 0)
+ err(1, "pthread_create");
+
+ asm volatile ("mov %%ss, %0" : "=rm" (orig_ss));
+
+ for (i = 0; i < 5; i++) {
+ if (sigsetjmp(jmpbuf, 1) != 0)
+ continue;
+
+ /* Make sure the thread is ready after the last test. */
+ while (ftx != 0)
+ ;
+
+ struct user_desc desc = {
+ .entry_number = 0,
+ .base_addr = 0,
+ .limit = 0xfffff,
+ .seg_32bit = 1,
+ .contents = 0, /* Data */
+ .read_exec_only = 0,
+ .limit_in_pages = 1,
+ .seg_not_present = 0,
+ .useable = 0
+ };
+
+ if (safe_modify_ldt(0x11, &desc, sizeof(desc)) != 0) {
+ if (errno != ENOSYS)
+ err(1, "modify_ldt");
+ printf("[SKIP]\tmodify_ldt unavailable\n");
+ break;
+ }
+
+ /* Arm the thread. */
+ ftx = 1;
+ syscall(SYS_futex, &ftx, FUTEX_WAKE, 0, NULL, NULL, 0);
+
+ asm volatile ("mov %0, %%ss" : : "r" (0x7));
+
+ /* Go! */
+ ftx = 2;
+
+ while (ftx != 0)
+ ;
+
+ /*
+ * On success, modify_ldt will segfault us synchronously,
+ * and we'll escape via siglongjmp.
+ */
+
+ failures++;
+ asm volatile ("mov %0, %%ss" : : "rm" (orig_ss));
+ };
+
+ ftx = 100; /* Kill the thread. */
+ syscall(SYS_futex, &ftx, FUTEX_WAKE, 0, NULL, NULL, 0);
+
+ if (pthread_join(thread, NULL) != 0)
+ err(1, "pthread_join");
+
+ if (failures) {
+ printf("[FAIL]\t%d of %d iterations failed\n", failures, iters);
+ nerrs++;
+ } else {
+ printf("[OK]\tAll %d iterations succeeded\n", iters);
+ }
+}
+
+static int finish_exec_test(void)
+{
+ /*
+ * In a sensible world, this would be check_invalid_segment(0, 1);
+ * For better or for worse, though, the LDT is inherited across exec.
+ * We can probably change this safely, but for now we test it.
+ */
+ check_valid_segment(0, 1,
+ AR_DPL3 | AR_TYPE_XRCODE | AR_S | AR_P | AR_DB,
+ 42, true);
+
+ return nerrs ? 1 : 0;
+}
+
+static void do_exec_test(void)
+{
+ printf("[RUN]\tTest exec\n");
+
+ struct user_desc desc = {
+ .entry_number = 0,
+ .base_addr = 0,
+ .limit = 42,
+ .seg_32bit = 1,
+ .contents = 2, /* Code, not conforming */
+ .read_exec_only = 0,
+ .limit_in_pages = 0,
+ .seg_not_present = 0,
+ .useable = 0
+ };
+ install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE | AR_S | AR_P | AR_DB);
+
+ pid_t child = fork();
+ if (child == 0) {
+ execl("/proc/self/exe", "ldt_gdt_test_exec", NULL);
+ printf("[FAIL]\tCould not exec self\n");
+ exit(1); /* exec failed */
+ } else {
+ int status;
+ if (waitpid(child, &status, 0) != child ||
+ !WIFEXITED(status)) {
+ printf("[FAIL]\tChild died\n");
+ nerrs++;
+ } else if (WEXITSTATUS(status) != 0) {
+ printf("[FAIL]\tChild failed\n");
+ nerrs++;
+ } else {
+ printf("[OK]\tChild succeeded\n");
+ }
+ }
+}
+
+int main(int argc, char **argv)
+{
+ if (argc == 1 && !strcmp(argv[0], "ldt_gdt_test_exec"))
+ return finish_exec_test();
+
+ do_simple_tests();
+
+ do_multicpu_tests();
+
+ do_exec_test();
+
+ return nerrs ? 1 : 0;
+}
diff --git a/tools/testing/selftests/x86/syscall_arg_fault.c b/tools/testing/selftests/x86/syscall_arg_fault.c
new file mode 100644
index 000000000000..7db4fc9fa09f
--- /dev/null
+++ b/tools/testing/selftests/x86/syscall_arg_fault.c
@@ -0,0 +1,130 @@
+/*
+ * syscall_arg_fault.c - tests faults 32-bit fast syscall stack args
+ * 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.
+ */
+
+#define _GNU_SOURCE
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/signal.h>
+#include <sys/ucontext.h>
+#include <err.h>
+#include <setjmp.h>
+#include <errno.h>
+
+/* Our sigaltstack scratch space. */
+static unsigned char altstack_data[SIGSTKSZ];
+
+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;
+static sigjmp_buf jmpbuf;
+
+static volatile sig_atomic_t n_errs;
+
+static void sigsegv(int sig, siginfo_t *info, void *ctx_void)
+{
+ ucontext_t *ctx = (ucontext_t*)ctx_void;
+
+ if (ctx->uc_mcontext.gregs[REG_EAX] != -EFAULT) {
+ printf("[FAIL]\tAX had the wrong value: 0x%x\n",
+ ctx->uc_mcontext.gregs[REG_EAX]);
+ n_errs++;
+ } else {
+ printf("[OK]\tSeems okay\n");
+ }
+
+ siglongjmp(jmpbuf, 1);
+}
+
+static void sigill(int sig, siginfo_t *info, void *ctx_void)
+{
+ printf("[SKIP]\tIllegal instruction\n");
+ siglongjmp(jmpbuf, 1);
+}
+
+int main()
+{
+ stack_t stack = {
+ .ss_sp = altstack_data,
+ .ss_size = SIGSTKSZ,
+ };
+ if (sigaltstack(&stack, NULL) != 0)
+ err(1, "sigaltstack");
+
+ sethandler(SIGSEGV, sigsegv, SA_ONSTACK);
+ sethandler(SIGILL, sigill, SA_ONSTACK);
+
+ /*
+ * Exercise another nasty special case. The 32-bit SYSCALL
+ * and SYSENTER instructions (even in compat mode) each
+ * clobber one register. A Linux system call has a syscall
+ * number and six arguments, and the user stack pointer
+ * needs to live in some register on return. That means
+ * that we need eight registers, but SYSCALL and SYSENTER
+ * only preserve seven registers. As a result, one argument
+ * ends up on the stack. The stack is user memory, which
+ * means that the kernel can fail to read it.
+ *
+ * The 32-bit fast system calls don't have a defined ABI:
+ * we're supposed to invoke them through the vDSO. So we'll
+ * fudge it: we set all regs to invalid pointer values and
+ * invoke the entry instruction. The return will fail no
+ * matter what, and we completely lose our program state,
+ * but we can fix it up with a signal handler.
+ */
+
+ printf("[RUN]\tSYSENTER with invalid state\n");
+ if (sigsetjmp(jmpbuf, 1) == 0) {
+ asm volatile (
+ "movl $-1, %%eax\n\t"
+ "movl $-1, %%ebx\n\t"
+ "movl $-1, %%ecx\n\t"
+ "movl $-1, %%edx\n\t"
+ "movl $-1, %%esi\n\t"
+ "movl $-1, %%edi\n\t"
+ "movl $-1, %%ebp\n\t"
+ "movl $-1, %%esp\n\t"
+ "sysenter"
+ : : : "memory", "flags");
+ }
+
+ printf("[RUN]\tSYSCALL with invalid state\n");
+ if (sigsetjmp(jmpbuf, 1) == 0) {
+ asm volatile (
+ "movl $-1, %%eax\n\t"
+ "movl $-1, %%ebx\n\t"
+ "movl $-1, %%ecx\n\t"
+ "movl $-1, %%edx\n\t"
+ "movl $-1, %%esi\n\t"
+ "movl $-1, %%edi\n\t"
+ "movl $-1, %%ebp\n\t"
+ "movl $-1, %%esp\n\t"
+ "syscall\n\t"
+ "pushl $0" /* make sure we segfault cleanly */
+ : : : "memory", "flags");
+ }
+
+ return 0;
+}
diff --git a/tools/testing/selftests/x86/syscall_nt.c b/tools/testing/selftests/x86/syscall_nt.c
new file mode 100644
index 000000000000..60c06af4646a
--- /dev/null
+++ b/tools/testing/selftests/x86/syscall_nt.c
@@ -0,0 +1,54 @@
+/*
+ * syscall_nt.c - checks syscalls with NT set
+ * 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.
+ *
+ * Some obscure user-space code requires the ability to make system calls
+ * with FLAGS.NT set. Make sure it works.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <asm/processor-flags.h>
+
+#ifdef __x86_64__
+# define WIDTH "q"
+#else
+# 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");
+}
+
+int main()
+{
+ printf("[RUN]\tSet NT and issue a syscall\n");
+ set_eflags(get_eflags() | X86_EFLAGS_NT);
+ syscall(SYS_getpid);
+ if (get_eflags() & X86_EFLAGS_NT) {
+ printf("[OK]\tThe syscall worked and NT is still set\n");
+ return 0;
+ } else {
+ printf("[FAIL]\tThe syscall worked but NT was cleared\n");
+ return 1;
+ }
+}

Privacy Policy