Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1616 insertions, 0 deletions

diff --git a/tools/testing/selftests/x86/mpx-mini-test.c b/tools/testing/selftests/x86/mpx-mini-test.c
new file mode 100644
index 000000000..50f7e9272
--- /dev/null
+++ b/tools/testing/selftests/x86/mpx-mini-test.c
@@ -0,0 +1,1616 @@
+/*
+ * mpx-mini-test.c: routines to test Intel MPX (Memory Protection eXtentions)
+ *
+ * Written by:
+ * "Ren, Qiaowei" <qiaowei.ren@intel.com>
+ * "Wei, Gang" <gang.wei@intel.com>
+ * "Hansen, Dave" <dave.hansen@intel.com>
+ *
+ * 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.
+ */
+
+/*
+ * 2014-12-05: Dave Hansen: fixed all of the compiler warnings, and made sure
+ *	       it works on 32-bit.
+ */
+
+int inspect_every_this_many_mallocs = 100;
+int zap_all_every_this_many_mallocs = 1000;
+
+#define _GNU_SOURCE
+#define _LARGEFILE64_SOURCE
+
+#include <string.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <signal.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <ucontext.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "mpx-hw.h"
+#include "mpx-debug.h"
+#include "mpx-mm.h"
+
+#ifndef __always_inline
+#define __always_inline inline __attribute__((always_inline)
+#endif
+
+#ifndef TEST_DURATION_SECS
+#define TEST_DURATION_SECS 3
+#endif
+
+void write_int_to(char *prefix, char *file, int int_to_write)
+{
+	char buf[100];
+	int fd = open(file, O_RDWR);
+	int len;
+	int ret;
+
+	assert(fd >= 0);
+	len = snprintf(buf, sizeof(buf), "%s%d", prefix, int_to_write);
+	assert(len >= 0);
+	assert(len < sizeof(buf));
+	ret = write(fd, buf, len);
+	assert(ret == len);
+	ret = close(fd);
+	assert(!ret);
+}
+
+void write_pid_to(char *prefix, char *file)
+{
+	write_int_to(prefix, file, getpid());
+}
+
+void trace_me(void)
+{
+/* tracing events dir */
+#define TED "/sys/kernel/debug/tracing/events/"
+/*
+	write_pid_to("common_pid=", TED "signal/filter");
+	write_pid_to("common_pid=", TED "exceptions/filter");
+	write_int_to("", TED "signal/enable", 1);
+	write_int_to("", TED "exceptions/enable", 1);
+*/
+	write_pid_to("", "/sys/kernel/debug/tracing/set_ftrace_pid");
+	write_int_to("", "/sys/kernel/debug/tracing/trace", 0);
+}
+
+#define test_failed() __test_failed(__FILE__, __LINE__)
+static void __test_failed(char *f, int l)
+{
+	fprintf(stderr, "abort @ %s::%d\n", f, l);
+	abort();
+}
+
+/* Error Printf */
+#define eprintf(args...)	fprintf(stderr, args)
+
+#ifdef __i386__
+
+/* i386 directory size is 4MB */
+#define REG_IP_IDX	REG_EIP
+#define REX_PREFIX
+
+#define XSAVE_OFFSET_IN_FPMEM	sizeof(struct _libc_fpstate)
+
+/*
+ * __cpuid() is from the Linux Kernel:
+ */
+static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
+		unsigned int *ecx, unsigned int *edx)
+{
+	/* ecx is often an input as well as an output. */
+	asm volatile(
+		"push %%ebx;"
+		"cpuid;"
+		"mov %%ebx, %1;"
+		"pop %%ebx"
+		: "=a" (*eax),
+		  "=g" (*ebx),
+		  "=c" (*ecx),
+		  "=d" (*edx)
+		: "0" (*eax), "2" (*ecx));
+}
+
+#else /* __i386__ */
+
+#define REG_IP_IDX	REG_RIP
+#define REX_PREFIX "0x48, "
+
+#define XSAVE_OFFSET_IN_FPMEM	0
+
+/*
+ * __cpuid() is from the Linux Kernel:
+ */
+static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
+		unsigned int *ecx, unsigned int *edx)
+{
+	/* ecx is often an input as well as an output. */
+	asm volatile(
+		"cpuid;"
+		: "=a" (*eax),
+		  "=b" (*ebx),
+		  "=c" (*ecx),
+		  "=d" (*edx)
+		: "0" (*eax), "2" (*ecx));
+}
+
+#endif /* !__i386__ */
+
+struct xsave_hdr_struct {
+	uint64_t xstate_bv;
+	uint64_t reserved1[2];
+	uint64_t reserved2[5];
+} __attribute__((packed));
+
+struct bndregs_struct {
+	uint64_t bndregs[8];
+} __attribute__((packed));
+
+struct bndcsr_struct {
+	uint64_t cfg_reg_u;
+	uint64_t status_reg;
+} __attribute__((packed));
+
+struct xsave_struct {
+	uint8_t fpu_sse[512];
+	struct xsave_hdr_struct xsave_hdr;
+	uint8_t ymm[256];
+	uint8_t lwp[128];
+	struct bndregs_struct bndregs;
+	struct bndcsr_struct bndcsr;
+} __attribute__((packed));
+
+uint8_t __attribute__((__aligned__(64))) buffer[4096];
+struct xsave_struct *xsave_buf = (struct xsave_struct *)buffer;
+
+uint8_t __attribute__((__aligned__(64))) test_buffer[4096];
+struct xsave_struct *xsave_test_buf = (struct xsave_struct *)test_buffer;
+
+uint64_t num_bnd_chk;
+
+static __always_inline void xrstor_state(struct xsave_struct *fx, uint64_t mask)
+{
+	uint32_t lmask = mask;
+	uint32_t hmask = mask >> 32;
+
+	asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
+		     : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
+		     :   "memory");
+}
+
+static __always_inline void xsave_state_1(void *_fx, uint64_t mask)
+{
+	uint32_t lmask = mask;
+	uint32_t hmask = mask >> 32;
+	unsigned char *fx = _fx;
+
+	asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x27\n\t"
+		     : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
+		     :   "memory");
+}
+
+static inline uint64_t xgetbv(uint32_t index)
+{
+	uint32_t eax, edx;
+
+	asm volatile(".byte 0x0f,0x01,0xd0" /* xgetbv */
+		     : "=a" (eax), "=d" (edx)
+		     : "c" (index));
+	return eax + ((uint64_t)edx << 32);
+}
+
+static uint64_t read_mpx_status_sig(ucontext_t *uctxt)
+{
+	memset(buffer, 0, sizeof(buffer));
+	memcpy(buffer,
+		(uint8_t *)uctxt->uc_mcontext.fpregs + XSAVE_OFFSET_IN_FPMEM,
+		sizeof(struct xsave_struct));
+
+	return xsave_buf->bndcsr.status_reg;
+}
+
+#include <pthread.h>
+
+static uint8_t *get_next_inst_ip(uint8_t *addr)
+{
+	uint8_t *ip = addr;
+	uint8_t sib;
+	uint8_t rm;
+	uint8_t mod;
+	uint8_t base;
+	uint8_t modrm;
+
+	/* determine the prefix. */
+	switch(*ip) {
+	case 0xf2:
+	case 0xf3:
+	case 0x66:
+		ip++;
+		break;
+	}
+
+	/* look for rex prefix */
+	if ((*ip & 0x40) == 0x40)
+		ip++;
+
+	/* Make sure we have a MPX instruction. */
+	if (*ip++ != 0x0f)
+		return addr;
+
+	/* Skip the op code byte. */
+	ip++;
+
+	/* Get the modrm byte. */
+	modrm = *ip++;
+
+	/* Break it down into parts. */
+	rm = modrm & 7;
+	mod = (modrm >> 6);
+
+	/* Init the parts of the address mode. */
+	base = 8;
+
+	/* Is it a mem mode? */
+	if (mod != 3) {
+		/* look for scaled indexed addressing */
+		if (rm == 4) {
+			/* SIB addressing */
+			sib = *ip++;
+			base = sib & 7;
+			switch (mod) {
+			case 0:
+				if (base == 5)
+					ip += 4;
+				break;
+
+			case 1:
+				ip++;
+				break;
+
+			case 2:
+				ip += 4;
+				break;
+			}
+
+		} else {
+			/* MODRM addressing */
+			switch (mod) {
+			case 0:
+				/* DISP32 addressing, no base */
+				if (rm == 5)
+					ip += 4;
+				break;
+
+			case 1:
+				ip++;
+				break;
+
+			case 2:
+				ip += 4;
+				break;
+			}
+		}
+	}
+	return ip;
+}
+
+#ifdef si_lower
+static inline void *__si_bounds_lower(siginfo_t *si)
+{
+	return si->si_lower;
+}
+
+static inline void *__si_bounds_upper(siginfo_t *si)
+{
+	return si->si_upper;
+}
+#else
+
+/*
+ * This deals with old version of _sigfault in some distros:
+ *
+
+old _sigfault:
+        struct {
+            void *si_addr;
+	} _sigfault;
+
+new _sigfault:
+	struct {
+		void __user *_addr;
+		int _trapno;
+		short _addr_lsb;
+		union {
+			struct {
+				void __user *_lower;
+				void __user *_upper;
+			} _addr_bnd;
+			__u32 _pkey;
+		};
+	} _sigfault;
+ *
+ */
+
+static inline void **__si_bounds_hack(siginfo_t *si)
+{
+	void *sigfault = &si->_sifields._sigfault;
+	void *end_sigfault = sigfault + sizeof(si->_sifields._sigfault);
+	int *trapno = (int*)end_sigfault;
+	/* skip _trapno and _addr_lsb */
+	void **__si_lower = (void**)(trapno + 2);
+
+	return __si_lower;
+}
+
+static inline void *__si_bounds_lower(siginfo_t *si)
+{
+	return *__si_bounds_hack(si);
+}
+
+static inline void *__si_bounds_upper(siginfo_t *si)
+{
+	return *(__si_bounds_hack(si) + 1);
+}
+#endif
+
+static int br_count;
+static int expected_bnd_index = -1;
+uint64_t shadow_plb[NR_MPX_BOUNDS_REGISTERS][2]; /* shadow MPX bound registers */
+unsigned long shadow_map[NR_MPX_BOUNDS_REGISTERS];
+
+/* Failed address bound checks: */
+#ifndef SEGV_BNDERR
+# define SEGV_BNDERR	3
+#endif
+
+/*
+ * The kernel is supposed to provide some information about the bounds
+ * exception in the siginfo.  It should match what we have in the bounds
+ * registers that we are checking against.  Just check against the shadow copy
+ * since it is easily available, and we also check that *it* matches the real
+ * registers.
+ */
+void check_siginfo_vs_shadow(siginfo_t* si)
+{
+	int siginfo_ok = 1;
+	void *shadow_lower = (void *)(unsigned long)shadow_plb[expected_bnd_index][0];
+	void *shadow_upper = (void *)(unsigned long)shadow_plb[expected_bnd_index][1];
+
+	if ((expected_bnd_index < 0) ||
+	    (expected_bnd_index >= NR_MPX_BOUNDS_REGISTERS)) {
+		fprintf(stderr, "ERROR: invalid expected_bnd_index: %d\n",
+			expected_bnd_index);
+		exit(6);
+	}
+	if (__si_bounds_lower(si) != shadow_lower)
+		siginfo_ok = 0;
+	if (__si_bounds_upper(si) != shadow_upper)
+		siginfo_ok = 0;
+
+	if (!siginfo_ok) {
+		fprintf(stderr, "ERROR: siginfo bounds do not match "
+			"shadow bounds for register %d\n", expected_bnd_index);
+		exit(7);
+	}
+}
+
+void handler(int signum, siginfo_t *si, void *vucontext)
+{
+	int i;
+	ucontext_t *uctxt = vucontext;
+	int trapno;
+	unsigned long ip;
+
+	dprintf1("entered signal handler\n");
+
+	trapno = uctxt->uc_mcontext.gregs[REG_TRAPNO];
+	ip = uctxt->uc_mcontext.gregs[REG_IP_IDX];
+
+	if (trapno == 5) {
+		typeof(si->si_addr) *si_addr_ptr = &si->si_addr;
+		uint64_t status = read_mpx_status_sig(uctxt);
+		uint64_t br_reason =  status & 0x3;
+
+		br_count++;
+		dprintf1("#BR 0x%jx (total seen: %d)\n", status, br_count);
+
+		dprintf2("Saw a #BR! status 0x%jx at %016lx br_reason: %jx\n",
+				status, ip, br_reason);
+		dprintf2("si_signo: %d\n", si->si_signo);
+		dprintf2("  signum: %d\n", signum);
+		dprintf2("info->si_code == SEGV_BNDERR: %d\n",
+				(si->si_code == SEGV_BNDERR));
+		dprintf2("info->si_code: %d\n", si->si_code);
+		dprintf2("info->si_lower: %p\n", __si_bounds_lower(si));
+		dprintf2("info->si_upper: %p\n", __si_bounds_upper(si));
+
+		for (i = 0; i < 8; i++)
+			dprintf3("[%d]: %p\n", i, si_addr_ptr[i]);
+		switch (br_reason) {
+		case 0: /* traditional BR */
+			fprintf(stderr,
+				"Undefined status with bound exception:%jx\n",
+				 status);
+			exit(5);
+		case 1: /* #BR MPX bounds exception */
+			/* these are normal and we expect to see them */
+
+			check_siginfo_vs_shadow(si);
+
+			dprintf1("bounds exception (normal): status 0x%jx at %p si_addr: %p\n",
+				status, (void *)ip, si->si_addr);
+			num_bnd_chk++;
+			uctxt->uc_mcontext.gregs[REG_IP_IDX] =
+				(greg_t)get_next_inst_ip((uint8_t *)ip);
+			break;
+		case 2:
+			fprintf(stderr, "#BR status == 2, missing bounds table,"
+					"kernel should have handled!!\n");
+			exit(4);
+			break;
+		default:
+			fprintf(stderr, "bound check error: status 0x%jx at %p\n",
+				status, (void *)ip);
+			num_bnd_chk++;
+			uctxt->uc_mcontext.gregs[REG_IP_IDX] =
+				(greg_t)get_next_inst_ip((uint8_t *)ip);
+			fprintf(stderr, "bound check error: si_addr %p\n", si->si_addr);
+			exit(3);
+		}
+	} else if (trapno == 14) {
+		eprintf("ERROR: In signal handler, page fault, trapno = %d, ip = %016lx\n",
+			trapno, ip);
+		eprintf("si_addr %p\n", si->si_addr);
+		eprintf("REG_ERR: %lx\n", (unsigned long)uctxt->uc_mcontext.gregs[REG_ERR]);
+		test_failed();
+	} else {
+		eprintf("unexpected trap %d! at 0x%lx\n", trapno, ip);
+		eprintf("si_addr %p\n", si->si_addr);
+		eprintf("REG_ERR: %lx\n", (unsigned long)uctxt->uc_mcontext.gregs[REG_ERR]);
+		test_failed();
+	}
+}
+
+static inline void cpuid_count(unsigned int op, int count,
+			       unsigned int *eax, unsigned int *ebx,
+			       unsigned int *ecx, unsigned int *edx)
+{
+	*eax = op;
+	*ecx = count;
+	__cpuid(eax, ebx, ecx, edx);
+}
+
+#define XSTATE_CPUID	    0x0000000d
+
+/*
+ * List of XSAVE features Linux knows about:
+ */
+enum xfeature_bit {
+	XSTATE_BIT_FP,
+	XSTATE_BIT_SSE,
+	XSTATE_BIT_YMM,
+	XSTATE_BIT_BNDREGS,
+	XSTATE_BIT_BNDCSR,
+	XSTATE_BIT_OPMASK,
+	XSTATE_BIT_ZMM_Hi256,
+	XSTATE_BIT_Hi16_ZMM,
+
+	XFEATURES_NR_MAX,
+};
+
+#define XSTATE_FP	       (1 << XSTATE_BIT_FP)
+#define XSTATE_SSE	      (1 << XSTATE_BIT_SSE)
+#define XSTATE_YMM	      (1 << XSTATE_BIT_YMM)
+#define XSTATE_BNDREGS	  (1 << XSTATE_BIT_BNDREGS)
+#define XSTATE_BNDCSR	   (1 << XSTATE_BIT_BNDCSR)
+#define XSTATE_OPMASK	   (1 << XSTATE_BIT_OPMASK)
+#define XSTATE_ZMM_Hi256	(1 << XSTATE_BIT_ZMM_Hi256)
+#define XSTATE_Hi16_ZMM	 (1 << XSTATE_BIT_Hi16_ZMM)
+
+#define MPX_XSTATES		(XSTATE_BNDREGS | XSTATE_BNDCSR) /* 0x18 */
+
+bool one_bit(unsigned int x, int bit)
+{
+	return !!(x & (1<<bit));
+}
+
+void print_state_component(int state_bit_nr, char *name)
+{
+	unsigned int eax, ebx, ecx, edx;
+	unsigned int state_component_size;
+	unsigned int state_component_supervisor;
+	unsigned int state_component_user;
+	unsigned int state_component_aligned;
+
+	/* See SDM Section 13.2 */
+	cpuid_count(XSTATE_CPUID, state_bit_nr, &eax, &ebx, &ecx, &edx);
+	assert(eax || ebx || ecx);
+	state_component_size = eax;
+	state_component_supervisor = ((!ebx) && one_bit(ecx, 0));
+	state_component_user = !one_bit(ecx, 0);
+	state_component_aligned = one_bit(ecx, 1);
+	printf("%8s: size: %d user: %d supervisor: %d aligned: %d\n",
+		name,
+		state_component_size,	    state_component_user,
+		state_component_supervisor, state_component_aligned);
+
+}
+
+/* Intel-defined CPU features, CPUID level 0x00000001 (ecx) */
+#define XSAVE_FEATURE_BIT       (26)  /* XSAVE/XRSTOR/XSETBV/XGETBV */
+#define OSXSAVE_FEATURE_BIT     (27) /* XSAVE enabled in the OS */
+
+bool check_mpx_support(void)
+{
+	unsigned int eax, ebx, ecx, edx;
+
+	cpuid_count(1, 0, &eax, &ebx, &ecx, &edx);
+
+	/* We can't do much without XSAVE, so just make these assert()'s */
+	if (!one_bit(ecx, XSAVE_FEATURE_BIT)) {
+		fprintf(stderr, "processor lacks XSAVE, can not run MPX tests\n");
+		exit(0);
+	}
+
+	if (!one_bit(ecx, OSXSAVE_FEATURE_BIT)) {
+		fprintf(stderr, "processor lacks OSXSAVE, can not run MPX tests\n");
+		exit(0);
+	}
+
+	/* CPUs not supporting the XSTATE CPUID leaf do not support MPX */
+	/* Is this redundant with the feature bit checks? */
+	cpuid_count(0, 0, &eax, &ebx, &ecx, &edx);
+	if (eax < XSTATE_CPUID) {
+		fprintf(stderr, "processor lacks XSTATE CPUID leaf,"
+				" can not run MPX tests\n");
+		exit(0);
+	}
+
+	printf("XSAVE is supported by HW & OS\n");
+
+	cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx);
+
+	printf("XSAVE processor supported state mask: 0x%x\n", eax);
+	printf("XSAVE OS supported state mask: 0x%jx\n", xgetbv(0));
+
+	/* Make sure that the MPX states are enabled in in XCR0 */
+	if ((eax & MPX_XSTATES) != MPX_XSTATES) {
+		fprintf(stderr, "processor lacks MPX XSTATE(s), can not run MPX tests\n");
+		exit(0);
+	}
+
+	/* Make sure the MPX states are supported by XSAVE* */
+	if ((xgetbv(0) & MPX_XSTATES) != MPX_XSTATES) {
+		fprintf(stderr, "MPX XSTATE(s) no enabled in XCR0, "
+				"can not run MPX tests\n");
+		exit(0);
+	}
+
+	print_state_component(XSTATE_BIT_BNDREGS, "BNDREGS");
+	print_state_component(XSTATE_BIT_BNDCSR,  "BNDCSR");
+
+	return true;
+}
+
+void enable_mpx(void *l1base)
+{
+	/* enable point lookup */
+	memset(buffer, 0, sizeof(buffer));
+	xrstor_state(xsave_buf, 0x18);
+
+	xsave_buf->xsave_hdr.xstate_bv = 0x10;
+	xsave_buf->bndcsr.cfg_reg_u = (unsigned long)l1base | 1;
+	xsave_buf->bndcsr.status_reg = 0;
+
+	dprintf2("bf xrstor\n");
+	dprintf2("xsave cndcsr: status %jx, configu %jx\n",
+	       xsave_buf->bndcsr.status_reg, xsave_buf->bndcsr.cfg_reg_u);
+	xrstor_state(xsave_buf, 0x18);
+	dprintf2("after xrstor\n");
+
+	xsave_state_1(xsave_buf, 0x18);
+
+	dprintf1("xsave bndcsr: status %jx, configu %jx\n",
+	       xsave_buf->bndcsr.status_reg, xsave_buf->bndcsr.cfg_reg_u);
+}
+
+#include <sys/prctl.h>
+
+struct mpx_bounds_dir *bounds_dir_ptr;
+
+unsigned long __bd_incore(const char *func, int line)
+{
+	unsigned long ret = nr_incore(bounds_dir_ptr, MPX_BOUNDS_DIR_SIZE_BYTES);
+	return ret;
+}
+#define bd_incore() __bd_incore(__func__, __LINE__)
+
+void check_clear(void *ptr, unsigned long sz)
+{
+	unsigned long *i;
+
+	for (i = ptr; (void *)i < ptr + sz; i++) {
+		if (*i) {
+			dprintf1("%p is NOT clear at %p\n", ptr, i);
+			assert(0);
+		}
+	}
+	dprintf1("%p is clear for %lx\n", ptr, sz);
+}
+
+void check_clear_bd(void)
+{
+	check_clear(bounds_dir_ptr, 2UL << 30);
+}
+
+#define USE_MALLOC_FOR_BOUNDS_DIR 1
+bool process_specific_init(void)
+{
+	unsigned long size;
+	unsigned long *dir;
+	/* Guarantee we have the space to align it, add padding: */
+	unsigned long pad = getpagesize();
+
+	size = 2UL << 30; /* 2GB */
+	if (sizeof(unsigned long) == 4)
+		size = 4UL << 20; /* 4MB */
+	dprintf1("trying to allocate %ld MB bounds directory\n", (size >> 20));
+
+	if (USE_MALLOC_FOR_BOUNDS_DIR) {
+		unsigned long _dir;
+
+		dir = malloc(size + pad);
+		assert(dir);
+		_dir = (unsigned long)dir;
+		_dir += 0xfffUL;
+		_dir &= ~0xfffUL;
+		dir = (void *)_dir;
+	} else {
+		/*
+		 * This makes debugging easier because the address
+		 * calculations are simpler:
+		 */
+		dir = mmap((void *)0x200000000000, size + pad,
+				PROT_READ|PROT_WRITE,
+				MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
+		if (dir == (void *)-1) {
+			perror("unable to allocate bounds directory");
+			abort();
+		}
+		check_clear(dir, size);
+	}
+	bounds_dir_ptr = (void *)dir;
+	madvise(bounds_dir_ptr, size, MADV_NOHUGEPAGE);
+	bd_incore();
+	dprintf1("bounds directory: 0x%p -> 0x%p\n", bounds_dir_ptr,
+			(char *)bounds_dir_ptr + size);
+	check_clear(dir, size);
+	enable_mpx(dir);
+	check_clear(dir, size);
+	if (prctl(43, 0, 0, 0, 0)) {
+		printf("no MPX support\n");
+		abort();
+		return false;
+	}
+	return true;
+}
+
+bool process_specific_finish(void)
+{
+	if (prctl(44)) {
+		printf("no MPX support\n");
+		return false;
+	}
+	return true;
+}
+
+void setup_handler()
+{
+	int r, rs;
+	struct sigaction newact;
+	struct sigaction oldact;
+
+	/* #BR is mapped to sigsegv */
+	int signum  = SIGSEGV;
+
+	newact.sa_handler = 0;   /* void(*)(int)*/
+	newact.sa_sigaction = handler; /* void (*)(int, siginfo_t*, void *) */
+
+	/*sigset_t - signals to block while in the handler */
+	/* get the old signal mask. */
+	rs = sigprocmask(SIG_SETMASK, 0, &newact.sa_mask);
+	assert(rs == 0);
+
+	/* call sa_sigaction, not sa_handler*/
+	newact.sa_flags = SA_SIGINFO;
+
+	newact.sa_restorer = 0;  /* void(*)(), obsolete */
+	r = sigaction(signum, &newact, &oldact);
+	assert(r == 0);
+}
+
+void mpx_prepare(void)
+{
+	dprintf2("%s()\n", __func__);
+	setup_handler();
+	process_specific_init();
+}
+
+void mpx_cleanup(void)
+{
+	printf("%s(): %jd BRs. bye...\n", __func__, num_bnd_chk);
+	process_specific_finish();
+}
+
+/*-------------- the following is test case ---------------*/
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <time.h>
+
+uint64_t num_lower_brs;
+uint64_t num_upper_brs;
+
+#define MPX_CONFIG_OFFSET 1024
+#define MPX_BOUNDS_OFFSET 960
+#define MPX_HEADER_OFFSET 512
+#define MAX_ADDR_TESTED (1<<28)
+#define TEST_ROUNDS 100
+
+/*
+      0F 1A /r BNDLDX-Load
+      0F 1B /r BNDSTX-Store Extended Bounds Using Address Translation
+   66 0F 1A /r BNDMOV bnd1, bnd2/m128
+   66 0F 1B /r BNDMOV bnd1/m128, bnd2
+   F2 0F 1A /r BNDCU bnd, r/m64
+   F2 0F 1B /r BNDCN bnd, r/m64
+   F3 0F 1A /r BNDCL bnd, r/m64
+   F3 0F 1B /r BNDMK bnd, m64
+*/
+
+static __always_inline void xsave_state(void *_fx, uint64_t mask)
+{
+	uint32_t lmask = mask;
+	uint32_t hmask = mask >> 32;
+	unsigned char *fx = _fx;
+
+	asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x27\n\t"
+		     : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
+		     :   "memory");
+}
+
+static __always_inline void mpx_clear_bnd0(void)
+{
+	long size = 0;
+	void *ptr = NULL;
+	/* F3 0F 1B /r BNDMK bnd, m64			*/
+	/* f3 0f 1b 04 11    bndmk  (%rcx,%rdx,1),%bnd0	*/
+	asm volatile(".byte 0xf3,0x0f,0x1b,0x04,0x11\n\t"
+		     : : "c" (ptr), "d" (size-1)
+		     :   "memory");
+}
+
+static __always_inline void mpx_make_bound_helper(unsigned long ptr,
+		unsigned long size)
+{
+	/* F3 0F 1B /r		BNDMK bnd, m64			*/
+	/* f3 0f 1b 04 11       bndmk  (%rcx,%rdx,1),%bnd0	*/
+	asm volatile(".byte 0xf3,0x0f,0x1b,0x04,0x11\n\t"
+		     : : "c" (ptr), "d" (size-1)
+		     :   "memory");
+}
+
+static __always_inline void mpx_check_lowerbound_helper(unsigned long ptr)
+{
+	/* F3 0F 1A /r	NDCL bnd, r/m64			*/
+	/* f3 0f 1a 01	bndcl  (%rcx),%bnd0		*/
+	asm volatile(".byte 0xf3,0x0f,0x1a,0x01\n\t"
+		     : : "c" (ptr)
+		     :   "memory");
+}
+
+static __always_inline void mpx_check_upperbound_helper(unsigned long ptr)
+{
+	/* F2 0F 1A /r	BNDCU bnd, r/m64	*/
+	/* f2 0f 1a 01	bndcu  (%rcx),%bnd0	*/
+	asm volatile(".byte 0xf2,0x0f,0x1a,0x01\n\t"
+		     : : "c" (ptr)
+		     :   "memory");
+}
+
+static __always_inline void mpx_movbndreg_helper()
+{
+	/* 66 0F 1B /r	BNDMOV bnd1/m128, bnd2	*/
+	/* 66 0f 1b c2	bndmov %bnd0,%bnd2	*/
+
+	asm volatile(".byte 0x66,0x0f,0x1b,0xc2\n\t");
+}
+
+static __always_inline void mpx_movbnd2mem_helper(uint8_t *mem)
+{
+	/* 66 0F 1B /r	BNDMOV bnd1/m128, bnd2	*/
+	/* 66 0f 1b 01	bndmov %bnd0,(%rcx)	*/
+	asm volatile(".byte 0x66,0x0f,0x1b,0x01\n\t"
+		     : : "c" (mem)
+		     :   "memory");
+}
+
+static __always_inline void mpx_movbnd_from_mem_helper(uint8_t *mem)
+{
+	/* 66 0F 1A /r	BNDMOV bnd1, bnd2/m128	*/
+	/* 66 0f 1a 01	bndmov (%rcx),%bnd0	*/
+	asm volatile(".byte 0x66,0x0f,0x1a,0x01\n\t"
+		     : : "c" (mem)
+		     :   "memory");
+}
+
+static __always_inline void mpx_store_dsc_helper(unsigned long ptr_addr,
+		unsigned long ptr_val)
+{
+	/* 0F 1B /r	BNDSTX-Store Extended Bounds Using Address Translation	*/
+	/* 0f 1b 04 11	bndstx %bnd0,(%rcx,%rdx,1)				*/
+	asm volatile(".byte 0x0f,0x1b,0x04,0x11\n\t"
+		     : : "c" (ptr_addr), "d" (ptr_val)
+		     :   "memory");
+}
+
+static __always_inline void mpx_load_dsc_helper(unsigned long ptr_addr,
+		unsigned long ptr_val)
+{
+	/* 0F 1A /r	BNDLDX-Load			*/
+	/*/ 0f 1a 04 11	bndldx (%rcx,%rdx,1),%bnd0	*/
+	asm volatile(".byte 0x0f,0x1a,0x04,0x11\n\t"
+		     : : "c" (ptr_addr), "d" (ptr_val)
+		     :   "memory");
+}
+
+void __print_context(void *__print_xsave_buffer, int line)
+{
+	uint64_t *bounds = (uint64_t *)(__print_xsave_buffer + MPX_BOUNDS_OFFSET);
+	uint64_t *cfg    = (uint64_t *)(__print_xsave_buffer + MPX_CONFIG_OFFSET);
+
+	int i;
+	eprintf("%s()::%d\n", "print_context", line);
+	for (i = 0; i < 4; i++) {
+		eprintf("bound[%d]: 0x%016lx 0x%016lx(0x%016lx)\n", i,
+		       (unsigned long)bounds[i*2],
+		       ~(unsigned long)bounds[i*2+1],
+			(unsigned long)bounds[i*2+1]);
+	}
+
+	eprintf("cpcfg: %jx  cpstatus: %jx\n", cfg[0], cfg[1]);
+}
+#define print_context(x) __print_context(x, __LINE__)
+#ifdef DEBUG
+#define dprint_context(x) print_context(x)
+#else
+#define dprint_context(x) do{}while(0)
+#endif
+
+void init()
+{
+	int i;
+
+	srand((unsigned int)time(NULL));
+
+	for (i = 0; i < 4; i++) {
+		shadow_plb[i][0] = 0;
+		shadow_plb[i][1] = ~(unsigned long)0;
+	}
+}
+
+long int __mpx_random(int line)
+{
+#ifdef NOT_SO_RANDOM
+	static long fake = 722122311;
+	fake += 563792075;
+	return fakse;
+#else
+	return random();
+#endif
+}
+#define mpx_random() __mpx_random(__LINE__)
+
+uint8_t *get_random_addr()
+{
+	uint8_t*addr = (uint8_t *)(unsigned long)(rand() % MAX_ADDR_TESTED);
+	return (addr - (unsigned long)addr % sizeof(uint8_t *));
+}
+
+static inline bool compare_context(void *__xsave_buffer)
+{
+	uint64_t *bounds = (uint64_t *)(__xsave_buffer + MPX_BOUNDS_OFFSET);
+
+	int i;
+	for (i = 0; i < 4; i++) {
+		dprintf3("shadow[%d]{%016lx/%016lx}\nbounds[%d]{%016lx/%016lx}\n",
+		       i, (unsigned long)shadow_plb[i][0], (unsigned long)shadow_plb[i][1],
+		       i, (unsigned long)bounds[i*2],     ~(unsigned long)bounds[i*2+1]);
+		if ((shadow_plb[i][0] != bounds[i*2]) ||
+		    (shadow_plb[i][1] != ~(unsigned long)bounds[i*2+1])) {
+			eprintf("ERROR comparing shadow to real bound register %d\n", i);
+			eprintf("shadow{0x%016lx/0x%016lx}\nbounds{0x%016lx/0x%016lx}\n",
+			       (unsigned long)shadow_plb[i][0], (unsigned long)shadow_plb[i][1],
+			       (unsigned long)bounds[i*2], (unsigned long)bounds[i*2+1]);
+			return false;
+		}
+	}
+
+	return true;
+}
+
+void mkbnd_shadow(uint8_t *ptr, int index, long offset)
+{
+	uint64_t *lower = (uint64_t *)&(shadow_plb[index][0]);
+	uint64_t *upper = (uint64_t *)&(shadow_plb[index][1]);
+	*lower = (unsigned long)ptr;
+	*upper = (unsigned long)ptr + offset - 1;
+}
+
+void check_lowerbound_shadow(uint8_t *ptr, int index)
+{
+	uint64_t *lower = (uint64_t *)&(shadow_plb[index][0]);
+	if (*lower > (uint64_t)(unsigned long)ptr)
+		num_lower_brs++;
+	else
+		dprintf1("LowerBoundChk passed:%p\n", ptr);
+}
+
+void check_upperbound_shadow(uint8_t *ptr, int index)
+{
+	uint64_t upper = *(uint64_t *)&(shadow_plb[index][1]);
+	if (upper < (uint64_t)(unsigned long)ptr)
+		num_upper_brs++;
+	else
+		dprintf1("UpperBoundChk passed:%p\n", ptr);
+}
+
+__always_inline void movbndreg_shadow(int src, int dest)
+{
+	shadow_plb[dest][0] = shadow_plb[src][0];
+	shadow_plb[dest][1] = shadow_plb[src][1];
+}
+
+__always_inline void movbnd2mem_shadow(int src, unsigned long *dest)
+{
+	unsigned long *lower = (unsigned long *)&(shadow_plb[src][0]);
+	unsigned long *upper = (unsigned long *)&(shadow_plb[src][1]);
+	*dest = *lower;
+	*(dest+1) = *upper;
+}
+
+__always_inline void movbnd_from_mem_shadow(unsigned long *src, int dest)
+{
+	unsigned long *lower = (unsigned long *)&(shadow_plb[dest][0]);
+	unsigned long *upper = (unsigned long *)&(shadow_plb[dest][1]);
+	*lower = *src;
+	*upper = *(src+1);
+}
+
+__always_inline void stdsc_shadow(int index, uint8_t *ptr, uint8_t *ptr_val)
+{
+	shadow_map[0] = (unsigned long)shadow_plb[index][0];
+	shadow_map[1] = (unsigned long)shadow_plb[index][1];
+	shadow_map[2] = (unsigned long)ptr_val;
+	dprintf3("%s(%d, %p, %p) set shadow map[2]: %p\n", __func__,
+			index, ptr, ptr_val, ptr_val);
+	/*ptr ignored */
+}
+
+void lddsc_shadow(int index, uint8_t *ptr, uint8_t *ptr_val)
+{
+	uint64_t lower = shadow_map[0];
+	uint64_t upper = shadow_map[1];
+	uint8_t *value = (uint8_t *)shadow_map[2];
+
+	if (value != ptr_val) {
+		dprintf2("%s(%d, %p, %p) init shadow bounds[%d] "
+			 "because %p != %p\n", __func__, index, ptr,
+			 ptr_val, index, value, ptr_val);
+		shadow_plb[index][0] = 0;
+		shadow_plb[index][1] = ~(unsigned long)0;
+	} else {
+		shadow_plb[index][0] = lower;
+		shadow_plb[index][1] = upper;
+	}
+	/* ptr ignored */
+}
+
+static __always_inline void mpx_test_helper0(uint8_t *buf, uint8_t *ptr)
+{
+	mpx_make_bound_helper((unsigned long)ptr, 0x1800);
+}
+
+static __always_inline void mpx_test_helper0_shadow(uint8_t *buf, uint8_t *ptr)
+{
+	mkbnd_shadow(ptr, 0, 0x1800);
+}
+
+static __always_inline void mpx_test_helper1(uint8_t *buf, uint8_t *ptr)
+{
+	/* these are hard-coded to check bnd0 */
+	expected_bnd_index = 0;
+	mpx_check_lowerbound_helper((unsigned long)(ptr-1));
+	mpx_check_upperbound_helper((unsigned long)(ptr+0x1800));
+	/* reset this since we do not expect any more bounds exceptions */
+	expected_bnd_index = -1;
+}
+
+static __always_inline void mpx_test_helper1_shadow(uint8_t *buf, uint8_t *ptr)
+{
+	check_lowerbound_shadow(ptr-1, 0);
+	check_upperbound_shadow(ptr+0x1800, 0);
+}
+
+static __always_inline void mpx_test_helper2(uint8_t *buf, uint8_t *ptr)
+{
+	mpx_make_bound_helper((unsigned long)ptr, 0x1800);
+	mpx_movbndreg_helper();
+	mpx_movbnd2mem_helper(buf);
+	mpx_make_bound_helper((unsigned long)(ptr+0x12), 0x1800);
+}
+
+static __always_inline void mpx_test_helper2_shadow(uint8_t *buf, uint8_t *ptr)
+{
+	mkbnd_shadow(ptr, 0, 0x1800);
+	movbndreg_shadow(0, 2);
+	movbnd2mem_shadow(0, (unsigned long *)buf);
+	mkbnd_shadow(ptr+0x12, 0, 0x1800);
+}
+
+static __always_inline void mpx_test_helper3(uint8_t *buf, uint8_t *ptr)
+{
+	mpx_movbnd_from_mem_helper(buf);
+}
+
+static __always_inline void mpx_test_helper3_shadow(uint8_t *buf, uint8_t *ptr)
+{
+	movbnd_from_mem_shadow((unsigned long *)buf, 0);
+}
+
+static __always_inline void mpx_test_helper4(uint8_t *buf, uint8_t *ptr)
+{
+	mpx_store_dsc_helper((unsigned long)buf, (unsigned long)ptr);
+	mpx_make_bound_helper((unsigned long)(ptr+0x12), 0x1800);
+}
+
+static __always_inline void mpx_test_helper4_shadow(uint8_t *buf, uint8_t *ptr)
+{
+	stdsc_shadow(0, buf, ptr);
+	mkbnd_shadow(ptr+0x12, 0, 0x1800);
+}
+
+static __always_inline void mpx_test_helper5(uint8_t *buf, uint8_t *ptr)
+{
+	mpx_load_dsc_helper((unsigned long)buf, (unsigned long)ptr);
+}
+
+static __always_inline void mpx_test_helper5_shadow(uint8_t *buf, uint8_t *ptr)
+{
+	lddsc_shadow(0, buf, ptr);
+}
+
+#define NR_MPX_TEST_FUNCTIONS 6
+
+/*
+ * For compatibility reasons, MPX will clear the bounds registers
+ * when you make function calls (among other things).  We have to
+ * preserve the registers in between calls to the "helpers" since
+ * they build on each other.
+ *
+ * Be very careful not to make any function calls inside the
+ * helpers, or anywhere else beween the xrstor and xsave.
+ */
+#define run_helper(helper_nr, buf, buf_shadow, ptr)	do {	\
+	xrstor_state(xsave_test_buf, flags);			\
+	mpx_test_helper##helper_nr(buf, ptr);			\
+	xsave_state(xsave_test_buf, flags);			\
+	mpx_test_helper##helper_nr##_shadow(buf_shadow, ptr);	\
+} while (0)
+
+static void run_helpers(int nr, uint8_t *buf, uint8_t *buf_shadow, uint8_t *ptr)
+{
+	uint64_t flags = 0x18;
+
+	dprint_context(xsave_test_buf);
+	switch (nr) {
+	case 0:
+		run_helper(0, buf, buf_shadow, ptr);
+		break;
+	case 1:
+		run_helper(1, buf, buf_shadow, ptr);
+		break;
+	case 2:
+		run_helper(2, buf, buf_shadow, ptr);
+		break;
+	case 3:
+		run_helper(3, buf, buf_shadow, ptr);
+		break;
+	case 4:
+		run_helper(4, buf, buf_shadow, ptr);
+		break;
+	case 5:
+		run_helper(5, buf, buf_shadow, ptr);
+		break;
+	default:
+		test_failed();
+		break;
+	}
+	dprint_context(xsave_test_buf);
+}
+
+unsigned long buf_shadow[1024]; /* used to check load / store descriptors */
+extern long inspect_me(struct mpx_bounds_dir *bounds_dir);
+
+long cover_buf_with_bt_entries(void *buf, long buf_len)
+{
+	int i;
+	long nr_to_fill;
+	int ratio = 1000;
+	unsigned long buf_len_in_ptrs;
+
+	/* Fill about 1/100 of the space with bt entries */
+	nr_to_fill = buf_len / (sizeof(unsigned long) * ratio);
+
+	if (!nr_to_fill)
+		dprintf3("%s() nr_to_fill: %ld\n", __func__, nr_to_fill);
+
+	/* Align the buffer to pointer size */
+	while (((unsigned long)buf) % sizeof(void *)) {
+		buf++;
+		buf_len--;
+	}
+	/* We are storing pointers, so make */
+	buf_len_in_ptrs = buf_len / sizeof(void *);
+
+	for (i = 0; i < nr_to_fill; i++) {
+		long index = (mpx_random() % buf_len_in_ptrs);
+		void *ptr = buf + index * sizeof(unsigned long);
+		unsigned long ptr_addr = (unsigned long)ptr;
+
+		/* ptr and size can be anything */
+		mpx_make_bound_helper((unsigned long)ptr, 8);
+
+		/*
+		 * take bnd0 and put it in to bounds tables "buf + index" is an
+		 * address inside the buffer where we are pretending that we
+		 * are going to put a pointer We do not, though because we will
+		 * never load entries from the table, so it doesn't matter.
+		 */
+		mpx_store_dsc_helper(ptr_addr, (unsigned long)ptr);
+		dprintf4("storing bound table entry for %lx (buf start @ %p)\n",
+				ptr_addr, buf);
+	}
+	return nr_to_fill;
+}
+
+unsigned long align_down(unsigned long alignme, unsigned long align_to)
+{
+	return alignme & ~(align_to-1);
+}
+
+unsigned long align_up(unsigned long alignme, unsigned long align_to)
+{
+	return (alignme + align_to - 1) & ~(align_to-1);
+}
+
+/*
+ * Using 1MB alignment guarantees that each no allocation
+ * will overlap with another's bounds tables.
+ *
+ * We have to cook our own allocator here.  malloc() can
+ * mix other allocation with ours which means that even
+ * if we free all of our allocations, there might still
+ * be bounds tables for the *areas* since there is other
+ * valid memory there.
+ *
+ * We also can't use malloc() because a free() of an area
+ * might not free it back to the kernel.  We want it
+ * completely unmapped an malloc() does not guarantee
+ * that.
+ */
+#ifdef __i386__
+long alignment = 4096;
+long sz_alignment = 4096;
+#else
+long alignment = 1 * MB;
+long sz_alignment = 1 * MB;
+#endif
+void *mpx_mini_alloc(unsigned long sz)
+{
+	unsigned long long tries = 0;
+	static void *last;
+	void *ptr;
+	void *try_at;
+
+	sz = align_up(sz, sz_alignment);
+
+	try_at = last + alignment;
+	while (1) {
+		ptr = mmap(try_at, sz, PROT_READ|PROT_WRITE,
+				MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
+		if (ptr == (void *)-1)
+			return NULL;
+		if (ptr == try_at)
+			break;
+
+		munmap(ptr, sz);
+		try_at += alignment;
+#ifdef __i386__
+		/*
+		 * This isn't quite correct for 32-bit binaries
+		 * on 64-bit kernels since they can use the
+		 * entire 32-bit address space, but it's close
+		 * enough.
+		 */
+		if (try_at > (void *)0xC0000000)
+#else
+		if (try_at > (void *)0x0000800000000000)
+#endif
+			try_at = (void *)0x0;
+		if (!(++tries % 10000))
+			dprintf1("stuck in %s(), tries: %lld\n", __func__, tries);
+		continue;
+	}
+	last = ptr;
+	dprintf3("mpx_mini_alloc(0x%lx) returning: %p\n", sz, ptr);
+	return ptr;
+}
+void mpx_mini_free(void *ptr, long sz)
+{
+	dprintf2("%s() ptr: %p\n", __func__, ptr);
+	if ((unsigned long)ptr > 0x100000000000) {
+		dprintf1("uh oh !!!!!!!!!!!!!!! pointer too high: %p\n", ptr);
+		test_failed();
+	}
+	sz = align_up(sz, sz_alignment);
+	dprintf3("%s() ptr: %p before munmap\n", __func__, ptr);
+	munmap(ptr, sz);
+	dprintf3("%s() ptr: %p DONE\n", __func__, ptr);
+}
+
+#define NR_MALLOCS 100
+struct one_malloc {
+	char *ptr;
+	int nr_filled_btes;
+	unsigned long size;
+};
+struct one_malloc mallocs[NR_MALLOCS];
+
+void free_one_malloc(int index)
+{
+	unsigned long free_ptr;
+	unsigned long mask;
+
+	if (!mallocs[index].ptr)
+		return;
+
+	mpx_mini_free(mallocs[index].ptr, mallocs[index].size);
+	dprintf4("freed[%d]:  %p\n", index, mallocs[index].ptr);
+
+	free_ptr = (unsigned long)mallocs[index].ptr;
+	mask = alignment-1;
+	dprintf4("lowerbits: %lx / %lx mask: %lx\n", free_ptr,
+			(free_ptr & mask), mask);
+	assert((free_ptr & mask) == 0);
+
+	mallocs[index].ptr = NULL;
+}
+
+#ifdef __i386__
+#define MPX_BOUNDS_TABLE_COVERS 4096
+#else
+#define MPX_BOUNDS_TABLE_COVERS (1 * MB)
+#endif
+void zap_everything(void)
+{
+	long after_zap;
+	long before_zap;
+	int i;
+
+	before_zap = inspect_me(bounds_dir_ptr);
+	dprintf1("zapping everything start: %ld\n", before_zap);
+	for (i = 0; i < NR_MALLOCS; i++)
+		free_one_malloc(i);
+
+	after_zap = inspect_me(bounds_dir_ptr);
+	dprintf1("zapping everything done: %ld\n", after_zap);
+	/*
+	 * We only guarantee to empty the thing out if our allocations are
+	 * exactly aligned on the boundaries of a boudns table.
+	 */
+	if ((alignment >= MPX_BOUNDS_TABLE_COVERS) &&
+	    (sz_alignment >= MPX_BOUNDS_TABLE_COVERS)) {
+		if (after_zap != 0)
+			test_failed();
+
+		assert(after_zap == 0);
+	}
+}
+
+void do_one_malloc(void)
+{
+	static int malloc_counter;
+	long sz;
+	int rand_index = (mpx_random() % NR_MALLOCS);
+	void *ptr = mallocs[rand_index].ptr;
+
+	dprintf3("%s() enter\n", __func__);
+
+	if (ptr) {
+		dprintf3("freeing one malloc at index: %d\n", rand_index);
+		free_one_malloc(rand_index);
+		if (mpx_random() % (NR_MALLOCS*3) == 3) {
+			int i;
+			dprintf3("zapping some more\n");
+			for (i = rand_index; i < NR_MALLOCS; i++)
+				free_one_malloc(i);
+		}
+		if ((mpx_random() % zap_all_every_this_many_mallocs) == 4)
+			zap_everything();
+	}
+
+	/* 1->~1M */
+	sz = (1 + mpx_random() % 1000) * 1000;
+	ptr = mpx_mini_alloc(sz);
+	if (!ptr) {
+		/*
+		 * If we are failing allocations, just assume we
+		 * are out of memory and zap everything.
+		 */
+		dprintf3("zapping everything because out of memory\n");
+		zap_everything();
+		goto out;
+	}
+
+	dprintf3("malloc: %p size: 0x%lx\n", ptr, sz);
+	mallocs[rand_index].nr_filled_btes = cover_buf_with_bt_entries(ptr, sz);
+	mallocs[rand_index].ptr = ptr;
+	mallocs[rand_index].size = sz;
+out:
+	if ((++malloc_counter) % inspect_every_this_many_mallocs == 0)
+		inspect_me(bounds_dir_ptr);
+}
+
+void run_timed_test(void (*test_func)(void))
+{
+	int done = 0;
+	long iteration = 0;
+	static time_t last_print;
+	time_t now;
+	time_t start;
+
+	time(&start);
+	while (!done) {
+		time(&now);
+		if ((now - start) > TEST_DURATION_SECS)
+			done = 1;
+
+		test_func();
+		iteration++;
+
+		if ((now - last_print > 1) || done) {
+			printf("iteration %ld complete, OK so far\n", iteration);
+			last_print = now;
+		}
+	}
+}
+
+void check_bounds_table_frees(void)
+{
+	printf("executing unmaptest\n");
+	inspect_me(bounds_dir_ptr);
+	run_timed_test(&do_one_malloc);
+	printf("done with malloc() fun\n");
+}
+
+void insn_test_failed(int test_nr, int test_round, void *buf,
+		void *buf_shadow, void *ptr)
+{
+	print_context(xsave_test_buf);
+	eprintf("ERROR: test %d round %d failed\n", test_nr, test_round);
+	while (test_nr == 5) {
+		struct mpx_bt_entry *bte;
+		struct mpx_bounds_dir *bd = (void *)bounds_dir_ptr;
+		struct mpx_bd_entry *bde = mpx_vaddr_to_bd_entry(buf, bd);
+
+		printf("  bd: %p\n", bd);
+		printf("&bde: %p\n", bde);
+		printf("*bde: %lx\n", *(unsigned long *)bde);
+		if (!bd_entry_valid(bde))
+			break;
+
+		bte = mpx_vaddr_to_bt_entry(buf, bd);
+		printf(" te: %p\n", bte);
+		printf("bte[0]: %lx\n", bte->contents[0]);
+		printf("bte[1]: %lx\n", bte->contents[1]);
+		printf("bte[2]: %lx\n", bte->contents[2]);
+		printf("bte[3]: %lx\n", bte->contents[3]);
+		break;
+	}
+	test_failed();
+}
+
+void check_mpx_insns_and_tables(void)
+{
+	int successes = 0;
+	int failures  = 0;
+	int buf_size = (1024*1024);
+	unsigned long *buf = malloc(buf_size);
+	const int total_nr_tests = NR_MPX_TEST_FUNCTIONS * TEST_ROUNDS;
+	int i, j;
+
+	memset(buf, 0, buf_size);
+	memset(buf_shadow, 0, sizeof(buf_shadow));
+
+	for (i = 0; i < TEST_ROUNDS; i++) {
+		uint8_t *ptr = get_random_addr() + 8;
+
+		for (j = 0; j < NR_MPX_TEST_FUNCTIONS; j++) {
+			if (0 && j != 5) {
+				successes++;
+				continue;
+			}
+			dprintf2("starting test %d round %d\n", j, i);
+			dprint_context(xsave_test_buf);
+			/*
+			 * test5 loads an address from the bounds tables.
+			 * The load will only complete if 'ptr' matches
+			 * the load and the store, so with random addrs,
+			 * the odds of this are very small.  Make it
+			 * higher by only moving 'ptr' 1/10 times.
+			 */
+			if (random() % 10 <= 0)
+				ptr = get_random_addr() + 8;
+			dprintf3("random ptr{%p}\n", ptr);
+			dprint_context(xsave_test_buf);
+			run_helpers(j, (void *)buf, (void *)buf_shadow, ptr);
+			dprint_context(xsave_test_buf);
+			if (!compare_context(xsave_test_buf)) {
+				insn_test_failed(j, i, buf, buf_shadow, ptr);
+				failures++;
+				goto exit;
+			}
+			successes++;
+			dprint_context(xsave_test_buf);
+			dprintf2("finished test %d round %d\n", j, i);
+			dprintf3("\n");
+			dprint_context(xsave_test_buf);
+		}
+	}
+
+exit:
+	dprintf2("\nabout to free:\n");
+	free(buf);
+	dprintf1("successes: %d\n", successes);
+	dprintf1(" failures: %d\n", failures);
+	dprintf1("    tests: %d\n", total_nr_tests);
+	dprintf1(" expected: %jd #BRs\n", num_upper_brs + num_lower_brs);
+	dprintf1("      saw: %d #BRs\n", br_count);
+	if (failures) {
+		eprintf("ERROR: non-zero number of failures\n");
+		exit(20);
+	}
+	if (successes != total_nr_tests) {
+		eprintf("ERROR: succeded fewer than number of tries (%d != %d)\n",
+				successes, total_nr_tests);
+		exit(21);
+	}
+	if (num_upper_brs + num_lower_brs != br_count) {
+		eprintf("ERROR: unexpected number of #BRs: %jd %jd %d\n",
+				num_upper_brs, num_lower_brs, br_count);
+		eprintf("successes: %d\n", successes);
+		eprintf(" failures: %d\n", failures);
+		eprintf("    tests: %d\n", total_nr_tests);
+		eprintf(" expected: %jd #BRs\n", num_upper_brs + num_lower_brs);
+		eprintf("      saw: %d #BRs\n", br_count);
+		exit(22);
+	}
+}
+
+/*
+ * This is supposed to SIGSEGV nicely once the kernel
+ * can no longer allocate vaddr space.
+ */
+void exhaust_vaddr_space(void)
+{
+	unsigned long ptr;
+	/* Try to make sure there is no room for a bounds table anywhere */
+	unsigned long skip = MPX_BOUNDS_TABLE_SIZE_BYTES - PAGE_SIZE;
+#ifdef __i386__
+	unsigned long max_vaddr = 0xf7788000UL;
+#else
+	unsigned long max_vaddr = 0x800000000000UL;
+#endif
+
+	dprintf1("%s() start\n", __func__);
+	/* do not start at 0, we aren't allowed to map there */
+	for (ptr = PAGE_SIZE; ptr < max_vaddr; ptr += skip) {
+		void *ptr_ret;
+		int ret = madvise((void *)ptr, PAGE_SIZE, MADV_NORMAL);
+
+		if (!ret) {
+			dprintf1("madvise() %lx ret: %d\n", ptr, ret);
+			continue;
+		}
+		ptr_ret = mmap((void *)ptr, PAGE_SIZE, PROT_READ|PROT_WRITE,
+				MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
+		if (ptr_ret != (void *)ptr) {
+			perror("mmap");
+			dprintf1("mmap(%lx) ret: %p\n", ptr, ptr_ret);
+			break;
+		}
+		if (!(ptr & 0xffffff))
+			dprintf1("mmap(%lx) ret: %p\n", ptr, ptr_ret);
+	}
+	for (ptr = PAGE_SIZE; ptr < max_vaddr; ptr += skip) {
+		dprintf2("covering 0x%lx with bounds table entries\n", ptr);
+		cover_buf_with_bt_entries((void *)ptr, PAGE_SIZE);
+	}
+	dprintf1("%s() end\n", __func__);
+	printf("done with vaddr space fun\n");
+}
+
+void mpx_table_test(void)
+{
+	printf("starting mpx bounds table test\n");
+	run_timed_test(check_mpx_insns_and_tables);
+	printf("done with mpx bounds table test\n");
+}
+
+int main(int argc, char **argv)
+{
+	int unmaptest = 0;
+	int vaddrexhaust = 0;
+	int tabletest = 0;
+	int i;
+
+	check_mpx_support();
+	mpx_prepare();
+	srandom(11179);
+
+	bd_incore();
+	init();
+	bd_incore();
+
+	trace_me();
+
+	xsave_state((void *)xsave_test_buf, 0x1f);
+	if (!compare_context(xsave_test_buf))
+		printf("Init failed\n");
+
+	for (i = 1; i < argc; i++) {
+		if (!strcmp(argv[i], "unmaptest"))
+			unmaptest = 1;
+		if (!strcmp(argv[i], "vaddrexhaust"))
+			vaddrexhaust = 1;
+		if (!strcmp(argv[i], "tabletest"))
+			tabletest = 1;
+	}
+	if (!(unmaptest || vaddrexhaust || tabletest)) {
+		unmaptest = 1;
+		/* vaddrexhaust = 1; */
+		tabletest = 1;
+	}
+	if (unmaptest)
+		check_bounds_table_frees();
+	if (tabletest)
+		mpx_table_test();
+	if (vaddrexhaust)
+		exhaust_vaddr_space();
+	printf("%s completed successfully\n", argv[0]);
+	exit(0);
+}
+
+#include "mpx-dig.c"