1 /*
2 * mpx-mini-test.c: routines to test Intel MPX (Memory Protection eXtentions)
3 *
4 * Written by:
5 * "Ren, Qiaowei" <qiaowei.ren@intel.com>
6 * "Wei, Gang" <gang.wei@intel.com>
7 * "Hansen, Dave" <dave.hansen@intel.com>
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms and conditions of the GNU General Public License,
11 * version 2.
12 */
13
14 /*
15 * 2014-12-05: Dave Hansen: fixed all of the compiler warnings, and made sure
16 * it works on 32-bit.
17 */
18
19 int inspect_every_this_many_mallocs = 100;
20 int zap_all_every_this_many_mallocs = 1000;
21
22 #define _GNU_SOURCE
23 #define _LARGEFILE64_SOURCE
24
25 #include <string.h>
26 #include <stdio.h>
27 #include <stdint.h>
28 #include <stdbool.h>
29 #include <signal.h>
30 #include <assert.h>
31 #include <stdlib.h>
32 #include <ucontext.h>
33 #include <sys/mman.h>
34 #include <sys/types.h>
35 #include <sys/stat.h>
36 #include <fcntl.h>
37 #include <unistd.h>
38
39 #include "mpx-hw.h"
40 #include "mpx-debug.h"
41 #include "mpx-mm.h"
42
43 #ifndef __always_inline
44 #define __always_inline inline __attribute__((always_inline)
45 #endif
46
47 #ifndef TEST_DURATION_SECS
48 #define TEST_DURATION_SECS 3
49 #endif
50
write_int_to(char * prefix,char * file,int int_to_write)51 void write_int_to(char *prefix, char *file, int int_to_write)
52 {
53 char buf[100];
54 int fd = open(file, O_RDWR);
55 int len;
56 int ret;
57
58 assert(fd >= 0);
59 len = snprintf(buf, sizeof(buf), "%s%d", prefix, int_to_write);
60 assert(len >= 0);
61 assert(len < sizeof(buf));
62 ret = write(fd, buf, len);
63 assert(ret == len);
64 ret = close(fd);
65 assert(!ret);
66 }
67
write_pid_to(char * prefix,char * file)68 void write_pid_to(char *prefix, char *file)
69 {
70 write_int_to(prefix, file, getpid());
71 }
72
trace_me(void)73 void trace_me(void)
74 {
75 /* tracing events dir */
76 #define TED "/sys/kernel/debug/tracing/events/"
77 /*
78 write_pid_to("common_pid=", TED "signal/filter");
79 write_pid_to("common_pid=", TED "exceptions/filter");
80 write_int_to("", TED "signal/enable", 1);
81 write_int_to("", TED "exceptions/enable", 1);
82 */
83 write_pid_to("", "/sys/kernel/debug/tracing/set_ftrace_pid");
84 write_int_to("", "/sys/kernel/debug/tracing/trace", 0);
85 }
86
87 #define test_failed() __test_failed(__FILE__, __LINE__)
__test_failed(char * f,int l)88 static void __test_failed(char *f, int l)
89 {
90 fprintf(stderr, "abort @ %s::%d\n", f, l);
91 abort();
92 }
93
94 /* Error Printf */
95 #define eprintf(args...) fprintf(stderr, args)
96
97 #ifdef __i386__
98
99 /* i386 directory size is 4MB */
100 #define REG_IP_IDX REG_EIP
101 #define REX_PREFIX
102
103 #define XSAVE_OFFSET_IN_FPMEM sizeof(struct _libc_fpstate)
104
105 /*
106 * __cpuid() is from the Linux Kernel:
107 */
__cpuid(unsigned int * eax,unsigned int * ebx,unsigned int * ecx,unsigned int * edx)108 static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
109 unsigned int *ecx, unsigned int *edx)
110 {
111 /* ecx is often an input as well as an output. */
112 asm volatile(
113 "push %%ebx;"
114 "cpuid;"
115 "mov %%ebx, %1;"
116 "pop %%ebx"
117 : "=a" (*eax),
118 "=g" (*ebx),
119 "=c" (*ecx),
120 "=d" (*edx)
121 : "0" (*eax), "2" (*ecx));
122 }
123
124 #else /* __i386__ */
125
126 #define REG_IP_IDX REG_RIP
127 #define REX_PREFIX "0x48, "
128
129 #define XSAVE_OFFSET_IN_FPMEM 0
130
131 /*
132 * __cpuid() is from the Linux Kernel:
133 */
__cpuid(unsigned int * eax,unsigned int * ebx,unsigned int * ecx,unsigned int * edx)134 static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
135 unsigned int *ecx, unsigned int *edx)
136 {
137 /* ecx is often an input as well as an output. */
138 asm volatile(
139 "cpuid;"
140 : "=a" (*eax),
141 "=b" (*ebx),
142 "=c" (*ecx),
143 "=d" (*edx)
144 : "0" (*eax), "2" (*ecx));
145 }
146
147 #endif /* !__i386__ */
148
149 struct xsave_hdr_struct {
150 uint64_t xstate_bv;
151 uint64_t reserved1[2];
152 uint64_t reserved2[5];
153 } __attribute__((packed));
154
155 struct bndregs_struct {
156 uint64_t bndregs[8];
157 } __attribute__((packed));
158
159 struct bndcsr_struct {
160 uint64_t cfg_reg_u;
161 uint64_t status_reg;
162 } __attribute__((packed));
163
164 struct xsave_struct {
165 uint8_t fpu_sse[512];
166 struct xsave_hdr_struct xsave_hdr;
167 uint8_t ymm[256];
168 uint8_t lwp[128];
169 struct bndregs_struct bndregs;
170 struct bndcsr_struct bndcsr;
171 } __attribute__((packed));
172
173 uint8_t __attribute__((__aligned__(64))) buffer[4096];
174 struct xsave_struct *xsave_buf = (struct xsave_struct *)buffer;
175
176 uint8_t __attribute__((__aligned__(64))) test_buffer[4096];
177 struct xsave_struct *xsave_test_buf = (struct xsave_struct *)test_buffer;
178
179 uint64_t num_bnd_chk;
180
xrstor_state(struct xsave_struct * fx,uint64_t mask)181 static __always_inline void xrstor_state(struct xsave_struct *fx, uint64_t mask)
182 {
183 uint32_t lmask = mask;
184 uint32_t hmask = mask >> 32;
185
186 asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
187 : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
188 : "memory");
189 }
190
xsave_state_1(void * _fx,uint64_t mask)191 static __always_inline void xsave_state_1(void *_fx, uint64_t mask)
192 {
193 uint32_t lmask = mask;
194 uint32_t hmask = mask >> 32;
195 unsigned char *fx = _fx;
196
197 asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x27\n\t"
198 : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
199 : "memory");
200 }
201
xgetbv(uint32_t index)202 static inline uint64_t xgetbv(uint32_t index)
203 {
204 uint32_t eax, edx;
205
206 asm volatile(".byte 0x0f,0x01,0xd0" /* xgetbv */
207 : "=a" (eax), "=d" (edx)
208 : "c" (index));
209 return eax + ((uint64_t)edx << 32);
210 }
211
read_mpx_status_sig(ucontext_t * uctxt)212 static uint64_t read_mpx_status_sig(ucontext_t *uctxt)
213 {
214 memset(buffer, 0, sizeof(buffer));
215 memcpy(buffer,
216 (uint8_t *)uctxt->uc_mcontext.fpregs + XSAVE_OFFSET_IN_FPMEM,
217 sizeof(struct xsave_struct));
218
219 return xsave_buf->bndcsr.status_reg;
220 }
221
222 #include <pthread.h>
223
get_next_inst_ip(uint8_t * addr)224 static uint8_t *get_next_inst_ip(uint8_t *addr)
225 {
226 uint8_t *ip = addr;
227 uint8_t sib;
228 uint8_t rm;
229 uint8_t mod;
230 uint8_t base;
231 uint8_t modrm;
232
233 /* determine the prefix. */
234 switch(*ip) {
235 case 0xf2:
236 case 0xf3:
237 case 0x66:
238 ip++;
239 break;
240 }
241
242 /* look for rex prefix */
243 if ((*ip & 0x40) == 0x40)
244 ip++;
245
246 /* Make sure we have a MPX instruction. */
247 if (*ip++ != 0x0f)
248 return addr;
249
250 /* Skip the op code byte. */
251 ip++;
252
253 /* Get the modrm byte. */
254 modrm = *ip++;
255
256 /* Break it down into parts. */
257 rm = modrm & 7;
258 mod = (modrm >> 6);
259
260 /* Init the parts of the address mode. */
261 base = 8;
262
263 /* Is it a mem mode? */
264 if (mod != 3) {
265 /* look for scaled indexed addressing */
266 if (rm == 4) {
267 /* SIB addressing */
268 sib = *ip++;
269 base = sib & 7;
270 switch (mod) {
271 case 0:
272 if (base == 5)
273 ip += 4;
274 break;
275
276 case 1:
277 ip++;
278 break;
279
280 case 2:
281 ip += 4;
282 break;
283 }
284
285 } else {
286 /* MODRM addressing */
287 switch (mod) {
288 case 0:
289 /* DISP32 addressing, no base */
290 if (rm == 5)
291 ip += 4;
292 break;
293
294 case 1:
295 ip++;
296 break;
297
298 case 2:
299 ip += 4;
300 break;
301 }
302 }
303 }
304 return ip;
305 }
306
307 #ifdef si_lower
__si_bounds_lower(siginfo_t * si)308 static inline void *__si_bounds_lower(siginfo_t *si)
309 {
310 return si->si_lower;
311 }
312
__si_bounds_upper(siginfo_t * si)313 static inline void *__si_bounds_upper(siginfo_t *si)
314 {
315 return si->si_upper;
316 }
317 #else
318
319 /*
320 * This deals with old version of _sigfault in some distros:
321 *
322
323 old _sigfault:
324 struct {
325 void *si_addr;
326 } _sigfault;
327
328 new _sigfault:
329 struct {
330 void __user *_addr;
331 int _trapno;
332 short _addr_lsb;
333 union {
334 struct {
335 void __user *_lower;
336 void __user *_upper;
337 } _addr_bnd;
338 __u32 _pkey;
339 };
340 } _sigfault;
341 *
342 */
343
__si_bounds_hack(siginfo_t * si)344 static inline void **__si_bounds_hack(siginfo_t *si)
345 {
346 void *sigfault = &si->_sifields._sigfault;
347 void *end_sigfault = sigfault + sizeof(si->_sifields._sigfault);
348 int *trapno = (int*)end_sigfault;
349 /* skip _trapno and _addr_lsb */
350 void **__si_lower = (void**)(trapno + 2);
351
352 return __si_lower;
353 }
354
__si_bounds_lower(siginfo_t * si)355 static inline void *__si_bounds_lower(siginfo_t *si)
356 {
357 return *__si_bounds_hack(si);
358 }
359
__si_bounds_upper(siginfo_t * si)360 static inline void *__si_bounds_upper(siginfo_t *si)
361 {
362 return *(__si_bounds_hack(si) + 1);
363 }
364 #endif
365
366 static int br_count;
367 static int expected_bnd_index = -1;
368 uint64_t shadow_plb[NR_MPX_BOUNDS_REGISTERS][2]; /* shadow MPX bound registers */
369 unsigned long shadow_map[NR_MPX_BOUNDS_REGISTERS];
370
371 /* Failed address bound checks: */
372 #ifndef SEGV_BNDERR
373 # define SEGV_BNDERR 3
374 #endif
375
376 /*
377 * The kernel is supposed to provide some information about the bounds
378 * exception in the siginfo. It should match what we have in the bounds
379 * registers that we are checking against. Just check against the shadow copy
380 * since it is easily available, and we also check that *it* matches the real
381 * registers.
382 */
check_siginfo_vs_shadow(siginfo_t * si)383 void check_siginfo_vs_shadow(siginfo_t* si)
384 {
385 int siginfo_ok = 1;
386 void *shadow_lower = (void *)(unsigned long)shadow_plb[expected_bnd_index][0];
387 void *shadow_upper = (void *)(unsigned long)shadow_plb[expected_bnd_index][1];
388
389 if ((expected_bnd_index < 0) ||
390 (expected_bnd_index >= NR_MPX_BOUNDS_REGISTERS)) {
391 fprintf(stderr, "ERROR: invalid expected_bnd_index: %d\n",
392 expected_bnd_index);
393 exit(6);
394 }
395 if (__si_bounds_lower(si) != shadow_lower)
396 siginfo_ok = 0;
397 if (__si_bounds_upper(si) != shadow_upper)
398 siginfo_ok = 0;
399
400 if (!siginfo_ok) {
401 fprintf(stderr, "ERROR: siginfo bounds do not match "
402 "shadow bounds for register %d\n", expected_bnd_index);
403 exit(7);
404 }
405 }
406
handler(int signum,siginfo_t * si,void * vucontext)407 void handler(int signum, siginfo_t *si, void *vucontext)
408 {
409 int i;
410 ucontext_t *uctxt = vucontext;
411 int trapno;
412 unsigned long ip;
413
414 dprintf1("entered signal handler\n");
415
416 trapno = uctxt->uc_mcontext.gregs[REG_TRAPNO];
417 ip = uctxt->uc_mcontext.gregs[REG_IP_IDX];
418
419 if (trapno == 5) {
420 typeof(si->si_addr) *si_addr_ptr = &si->si_addr;
421 uint64_t status = read_mpx_status_sig(uctxt);
422 uint64_t br_reason = status & 0x3;
423
424 br_count++;
425 dprintf1("#BR 0x%jx (total seen: %d)\n", status, br_count);
426
427 dprintf2("Saw a #BR! status 0x%jx at %016lx br_reason: %jx\n",
428 status, ip, br_reason);
429 dprintf2("si_signo: %d\n", si->si_signo);
430 dprintf2(" signum: %d\n", signum);
431 dprintf2("info->si_code == SEGV_BNDERR: %d\n",
432 (si->si_code == SEGV_BNDERR));
433 dprintf2("info->si_code: %d\n", si->si_code);
434 dprintf2("info->si_lower: %p\n", __si_bounds_lower(si));
435 dprintf2("info->si_upper: %p\n", __si_bounds_upper(si));
436
437 for (i = 0; i < 8; i++)
438 dprintf3("[%d]: %p\n", i, si_addr_ptr[i]);
439 switch (br_reason) {
440 case 0: /* traditional BR */
441 fprintf(stderr,
442 "Undefined status with bound exception:%jx\n",
443 status);
444 exit(5);
445 case 1: /* #BR MPX bounds exception */
446 /* these are normal and we expect to see them */
447
448 check_siginfo_vs_shadow(si);
449
450 dprintf1("bounds exception (normal): status 0x%jx at %p si_addr: %p\n",
451 status, (void *)ip, si->si_addr);
452 num_bnd_chk++;
453 uctxt->uc_mcontext.gregs[REG_IP_IDX] =
454 (greg_t)get_next_inst_ip((uint8_t *)ip);
455 break;
456 case 2:
457 fprintf(stderr, "#BR status == 2, missing bounds table,"
458 "kernel should have handled!!\n");
459 exit(4);
460 break;
461 default:
462 fprintf(stderr, "bound check error: status 0x%jx at %p\n",
463 status, (void *)ip);
464 num_bnd_chk++;
465 uctxt->uc_mcontext.gregs[REG_IP_IDX] =
466 (greg_t)get_next_inst_ip((uint8_t *)ip);
467 fprintf(stderr, "bound check error: si_addr %p\n", si->si_addr);
468 exit(3);
469 }
470 } else if (trapno == 14) {
471 eprintf("ERROR: In signal handler, page fault, trapno = %d, ip = %016lx\n",
472 trapno, ip);
473 eprintf("si_addr %p\n", si->si_addr);
474 eprintf("REG_ERR: %lx\n", (unsigned long)uctxt->uc_mcontext.gregs[REG_ERR]);
475 test_failed();
476 } else {
477 eprintf("unexpected trap %d! at 0x%lx\n", trapno, ip);
478 eprintf("si_addr %p\n", si->si_addr);
479 eprintf("REG_ERR: %lx\n", (unsigned long)uctxt->uc_mcontext.gregs[REG_ERR]);
480 test_failed();
481 }
482 }
483
cpuid_count(unsigned int op,int count,unsigned int * eax,unsigned int * ebx,unsigned int * ecx,unsigned int * edx)484 static inline void cpuid_count(unsigned int op, int count,
485 unsigned int *eax, unsigned int *ebx,
486 unsigned int *ecx, unsigned int *edx)
487 {
488 *eax = op;
489 *ecx = count;
490 __cpuid(eax, ebx, ecx, edx);
491 }
492
493 #define XSTATE_CPUID 0x0000000d
494
495 /*
496 * List of XSAVE features Linux knows about:
497 */
498 enum xfeature_bit {
499 XSTATE_BIT_FP,
500 XSTATE_BIT_SSE,
501 XSTATE_BIT_YMM,
502 XSTATE_BIT_BNDREGS,
503 XSTATE_BIT_BNDCSR,
504 XSTATE_BIT_OPMASK,
505 XSTATE_BIT_ZMM_Hi256,
506 XSTATE_BIT_Hi16_ZMM,
507
508 XFEATURES_NR_MAX,
509 };
510
511 #define XSTATE_FP (1 << XSTATE_BIT_FP)
512 #define XSTATE_SSE (1 << XSTATE_BIT_SSE)
513 #define XSTATE_YMM (1 << XSTATE_BIT_YMM)
514 #define XSTATE_BNDREGS (1 << XSTATE_BIT_BNDREGS)
515 #define XSTATE_BNDCSR (1 << XSTATE_BIT_BNDCSR)
516 #define XSTATE_OPMASK (1 << XSTATE_BIT_OPMASK)
517 #define XSTATE_ZMM_Hi256 (1 << XSTATE_BIT_ZMM_Hi256)
518 #define XSTATE_Hi16_ZMM (1 << XSTATE_BIT_Hi16_ZMM)
519
520 #define MPX_XSTATES (XSTATE_BNDREGS | XSTATE_BNDCSR) /* 0x18 */
521
one_bit(unsigned int x,int bit)522 bool one_bit(unsigned int x, int bit)
523 {
524 return !!(x & (1<<bit));
525 }
526
print_state_component(int state_bit_nr,char * name)527 void print_state_component(int state_bit_nr, char *name)
528 {
529 unsigned int eax, ebx, ecx, edx;
530 unsigned int state_component_size;
531 unsigned int state_component_supervisor;
532 unsigned int state_component_user;
533 unsigned int state_component_aligned;
534
535 /* See SDM Section 13.2 */
536 cpuid_count(XSTATE_CPUID, state_bit_nr, &eax, &ebx, &ecx, &edx);
537 assert(eax || ebx || ecx);
538 state_component_size = eax;
539 state_component_supervisor = ((!ebx) && one_bit(ecx, 0));
540 state_component_user = !one_bit(ecx, 0);
541 state_component_aligned = one_bit(ecx, 1);
542 printf("%8s: size: %d user: %d supervisor: %d aligned: %d\n",
543 name,
544 state_component_size, state_component_user,
545 state_component_supervisor, state_component_aligned);
546
547 }
548
549 /* Intel-defined CPU features, CPUID level 0x00000001 (ecx) */
550 #define XSAVE_FEATURE_BIT (26) /* XSAVE/XRSTOR/XSETBV/XGETBV */
551 #define OSXSAVE_FEATURE_BIT (27) /* XSAVE enabled in the OS */
552
check_mpx_support(void)553 bool check_mpx_support(void)
554 {
555 unsigned int eax, ebx, ecx, edx;
556
557 cpuid_count(1, 0, &eax, &ebx, &ecx, &edx);
558
559 /* We can't do much without XSAVE, so just make these assert()'s */
560 if (!one_bit(ecx, XSAVE_FEATURE_BIT)) {
561 fprintf(stderr, "processor lacks XSAVE, can not run MPX tests\n");
562 exit(0);
563 }
564
565 if (!one_bit(ecx, OSXSAVE_FEATURE_BIT)) {
566 fprintf(stderr, "processor lacks OSXSAVE, can not run MPX tests\n");
567 exit(0);
568 }
569
570 /* CPUs not supporting the XSTATE CPUID leaf do not support MPX */
571 /* Is this redundant with the feature bit checks? */
572 cpuid_count(0, 0, &eax, &ebx, &ecx, &edx);
573 if (eax < XSTATE_CPUID) {
574 fprintf(stderr, "processor lacks XSTATE CPUID leaf,"
575 " can not run MPX tests\n");
576 exit(0);
577 }
578
579 printf("XSAVE is supported by HW & OS\n");
580
581 cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx);
582
583 printf("XSAVE processor supported state mask: 0x%x\n", eax);
584 printf("XSAVE OS supported state mask: 0x%jx\n", xgetbv(0));
585
586 /* Make sure that the MPX states are enabled in in XCR0 */
587 if ((eax & MPX_XSTATES) != MPX_XSTATES) {
588 fprintf(stderr, "processor lacks MPX XSTATE(s), can not run MPX tests\n");
589 exit(0);
590 }
591
592 /* Make sure the MPX states are supported by XSAVE* */
593 if ((xgetbv(0) & MPX_XSTATES) != MPX_XSTATES) {
594 fprintf(stderr, "MPX XSTATE(s) no enabled in XCR0, "
595 "can not run MPX tests\n");
596 exit(0);
597 }
598
599 print_state_component(XSTATE_BIT_BNDREGS, "BNDREGS");
600 print_state_component(XSTATE_BIT_BNDCSR, "BNDCSR");
601
602 return true;
603 }
604
enable_mpx(void * l1base)605 void enable_mpx(void *l1base)
606 {
607 /* enable point lookup */
608 memset(buffer, 0, sizeof(buffer));
609 xrstor_state(xsave_buf, 0x18);
610
611 xsave_buf->xsave_hdr.xstate_bv = 0x10;
612 xsave_buf->bndcsr.cfg_reg_u = (unsigned long)l1base | 1;
613 xsave_buf->bndcsr.status_reg = 0;
614
615 dprintf2("bf xrstor\n");
616 dprintf2("xsave cndcsr: status %jx, configu %jx\n",
617 xsave_buf->bndcsr.status_reg, xsave_buf->bndcsr.cfg_reg_u);
618 xrstor_state(xsave_buf, 0x18);
619 dprintf2("after xrstor\n");
620
621 xsave_state_1(xsave_buf, 0x18);
622
623 dprintf1("xsave bndcsr: status %jx, configu %jx\n",
624 xsave_buf->bndcsr.status_reg, xsave_buf->bndcsr.cfg_reg_u);
625 }
626
627 #include <sys/prctl.h>
628
629 struct mpx_bounds_dir *bounds_dir_ptr;
630
__bd_incore(const char * func,int line)631 unsigned long __bd_incore(const char *func, int line)
632 {
633 unsigned long ret = nr_incore(bounds_dir_ptr, MPX_BOUNDS_DIR_SIZE_BYTES);
634 return ret;
635 }
636 #define bd_incore() __bd_incore(__func__, __LINE__)
637
check_clear(void * ptr,unsigned long sz)638 void check_clear(void *ptr, unsigned long sz)
639 {
640 unsigned long *i;
641
642 for (i = ptr; (void *)i < ptr + sz; i++) {
643 if (*i) {
644 dprintf1("%p is NOT clear at %p\n", ptr, i);
645 assert(0);
646 }
647 }
648 dprintf1("%p is clear for %lx\n", ptr, sz);
649 }
650
check_clear_bd(void)651 void check_clear_bd(void)
652 {
653 check_clear(bounds_dir_ptr, 2UL << 30);
654 }
655
656 #define USE_MALLOC_FOR_BOUNDS_DIR 1
process_specific_init(void)657 bool process_specific_init(void)
658 {
659 unsigned long size;
660 unsigned long *dir;
661 /* Guarantee we have the space to align it, add padding: */
662 unsigned long pad = getpagesize();
663
664 size = 2UL << 30; /* 2GB */
665 if (sizeof(unsigned long) == 4)
666 size = 4UL << 20; /* 4MB */
667 dprintf1("trying to allocate %ld MB bounds directory\n", (size >> 20));
668
669 if (USE_MALLOC_FOR_BOUNDS_DIR) {
670 unsigned long _dir;
671
672 dir = malloc(size + pad);
673 assert(dir);
674 _dir = (unsigned long)dir;
675 _dir += 0xfffUL;
676 _dir &= ~0xfffUL;
677 dir = (void *)_dir;
678 } else {
679 /*
680 * This makes debugging easier because the address
681 * calculations are simpler:
682 */
683 dir = mmap((void *)0x200000000000, size + pad,
684 PROT_READ|PROT_WRITE,
685 MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
686 if (dir == (void *)-1) {
687 perror("unable to allocate bounds directory");
688 abort();
689 }
690 check_clear(dir, size);
691 }
692 bounds_dir_ptr = (void *)dir;
693 madvise(bounds_dir_ptr, size, MADV_NOHUGEPAGE);
694 bd_incore();
695 dprintf1("bounds directory: 0x%p -> 0x%p\n", bounds_dir_ptr,
696 (char *)bounds_dir_ptr + size);
697 check_clear(dir, size);
698 enable_mpx(dir);
699 check_clear(dir, size);
700 if (prctl(43, 0, 0, 0, 0)) {
701 printf("no MPX support\n");
702 abort();
703 return false;
704 }
705 return true;
706 }
707
process_specific_finish(void)708 bool process_specific_finish(void)
709 {
710 if (prctl(44)) {
711 printf("no MPX support\n");
712 return false;
713 }
714 return true;
715 }
716
setup_handler()717 void setup_handler()
718 {
719 int r, rs;
720 struct sigaction newact;
721 struct sigaction oldact;
722
723 /* #BR is mapped to sigsegv */
724 int signum = SIGSEGV;
725
726 newact.sa_handler = 0; /* void(*)(int)*/
727 newact.sa_sigaction = handler; /* void (*)(int, siginfo_t*, void *) */
728
729 /*sigset_t - signals to block while in the handler */
730 /* get the old signal mask. */
731 rs = sigprocmask(SIG_SETMASK, 0, &newact.sa_mask);
732 assert(rs == 0);
733
734 /* call sa_sigaction, not sa_handler*/
735 newact.sa_flags = SA_SIGINFO;
736
737 newact.sa_restorer = 0; /* void(*)(), obsolete */
738 r = sigaction(signum, &newact, &oldact);
739 assert(r == 0);
740 }
741
mpx_prepare(void)742 void mpx_prepare(void)
743 {
744 dprintf2("%s()\n", __func__);
745 setup_handler();
746 process_specific_init();
747 }
748
mpx_cleanup(void)749 void mpx_cleanup(void)
750 {
751 printf("%s(): %jd BRs. bye...\n", __func__, num_bnd_chk);
752 process_specific_finish();
753 }
754
755 /*-------------- the following is test case ---------------*/
756 #include <stdint.h>
757 #include <stdbool.h>
758 #include <stdlib.h>
759 #include <stdio.h>
760 #include <time.h>
761
762 uint64_t num_lower_brs;
763 uint64_t num_upper_brs;
764
765 #define MPX_CONFIG_OFFSET 1024
766 #define MPX_BOUNDS_OFFSET 960
767 #define MPX_HEADER_OFFSET 512
768 #define MAX_ADDR_TESTED (1<<28)
769 #define TEST_ROUNDS 100
770
771 /*
772 0F 1A /r BNDLDX-Load
773 0F 1B /r BNDSTX-Store Extended Bounds Using Address Translation
774 66 0F 1A /r BNDMOV bnd1, bnd2/m128
775 66 0F 1B /r BNDMOV bnd1/m128, bnd2
776 F2 0F 1A /r BNDCU bnd, r/m64
777 F2 0F 1B /r BNDCN bnd, r/m64
778 F3 0F 1A /r BNDCL bnd, r/m64
779 F3 0F 1B /r BNDMK bnd, m64
780 */
781
xsave_state(void * _fx,uint64_t mask)782 static __always_inline void xsave_state(void *_fx, uint64_t mask)
783 {
784 uint32_t lmask = mask;
785 uint32_t hmask = mask >> 32;
786 unsigned char *fx = _fx;
787
788 asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x27\n\t"
789 : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
790 : "memory");
791 }
792
mpx_clear_bnd0(void)793 static __always_inline void mpx_clear_bnd0(void)
794 {
795 long size = 0;
796 void *ptr = NULL;
797 /* F3 0F 1B /r BNDMK bnd, m64 */
798 /* f3 0f 1b 04 11 bndmk (%rcx,%rdx,1),%bnd0 */
799 asm volatile(".byte 0xf3,0x0f,0x1b,0x04,0x11\n\t"
800 : : "c" (ptr), "d" (size-1)
801 : "memory");
802 }
803
mpx_make_bound_helper(unsigned long ptr,unsigned long size)804 static __always_inline void mpx_make_bound_helper(unsigned long ptr,
805 unsigned long size)
806 {
807 /* F3 0F 1B /r BNDMK bnd, m64 */
808 /* f3 0f 1b 04 11 bndmk (%rcx,%rdx,1),%bnd0 */
809 asm volatile(".byte 0xf3,0x0f,0x1b,0x04,0x11\n\t"
810 : : "c" (ptr), "d" (size-1)
811 : "memory");
812 }
813
mpx_check_lowerbound_helper(unsigned long ptr)814 static __always_inline void mpx_check_lowerbound_helper(unsigned long ptr)
815 {
816 /* F3 0F 1A /r NDCL bnd, r/m64 */
817 /* f3 0f 1a 01 bndcl (%rcx),%bnd0 */
818 asm volatile(".byte 0xf3,0x0f,0x1a,0x01\n\t"
819 : : "c" (ptr)
820 : "memory");
821 }
822
mpx_check_upperbound_helper(unsigned long ptr)823 static __always_inline void mpx_check_upperbound_helper(unsigned long ptr)
824 {
825 /* F2 0F 1A /r BNDCU bnd, r/m64 */
826 /* f2 0f 1a 01 bndcu (%rcx),%bnd0 */
827 asm volatile(".byte 0xf2,0x0f,0x1a,0x01\n\t"
828 : : "c" (ptr)
829 : "memory");
830 }
831
mpx_movbndreg_helper()832 static __always_inline void mpx_movbndreg_helper()
833 {
834 /* 66 0F 1B /r BNDMOV bnd1/m128, bnd2 */
835 /* 66 0f 1b c2 bndmov %bnd0,%bnd2 */
836
837 asm volatile(".byte 0x66,0x0f,0x1b,0xc2\n\t");
838 }
839
mpx_movbnd2mem_helper(uint8_t * mem)840 static __always_inline void mpx_movbnd2mem_helper(uint8_t *mem)
841 {
842 /* 66 0F 1B /r BNDMOV bnd1/m128, bnd2 */
843 /* 66 0f 1b 01 bndmov %bnd0,(%rcx) */
844 asm volatile(".byte 0x66,0x0f,0x1b,0x01\n\t"
845 : : "c" (mem)
846 : "memory");
847 }
848
mpx_movbnd_from_mem_helper(uint8_t * mem)849 static __always_inline void mpx_movbnd_from_mem_helper(uint8_t *mem)
850 {
851 /* 66 0F 1A /r BNDMOV bnd1, bnd2/m128 */
852 /* 66 0f 1a 01 bndmov (%rcx),%bnd0 */
853 asm volatile(".byte 0x66,0x0f,0x1a,0x01\n\t"
854 : : "c" (mem)
855 : "memory");
856 }
857
mpx_store_dsc_helper(unsigned long ptr_addr,unsigned long ptr_val)858 static __always_inline void mpx_store_dsc_helper(unsigned long ptr_addr,
859 unsigned long ptr_val)
860 {
861 /* 0F 1B /r BNDSTX-Store Extended Bounds Using Address Translation */
862 /* 0f 1b 04 11 bndstx %bnd0,(%rcx,%rdx,1) */
863 asm volatile(".byte 0x0f,0x1b,0x04,0x11\n\t"
864 : : "c" (ptr_addr), "d" (ptr_val)
865 : "memory");
866 }
867
mpx_load_dsc_helper(unsigned long ptr_addr,unsigned long ptr_val)868 static __always_inline void mpx_load_dsc_helper(unsigned long ptr_addr,
869 unsigned long ptr_val)
870 {
871 /* 0F 1A /r BNDLDX-Load */
872 /*/ 0f 1a 04 11 bndldx (%rcx,%rdx,1),%bnd0 */
873 asm volatile(".byte 0x0f,0x1a,0x04,0x11\n\t"
874 : : "c" (ptr_addr), "d" (ptr_val)
875 : "memory");
876 }
877
__print_context(void * __print_xsave_buffer,int line)878 void __print_context(void *__print_xsave_buffer, int line)
879 {
880 uint64_t *bounds = (uint64_t *)(__print_xsave_buffer + MPX_BOUNDS_OFFSET);
881 uint64_t *cfg = (uint64_t *)(__print_xsave_buffer + MPX_CONFIG_OFFSET);
882
883 int i;
884 eprintf("%s()::%d\n", "print_context", line);
885 for (i = 0; i < 4; i++) {
886 eprintf("bound[%d]: 0x%016lx 0x%016lx(0x%016lx)\n", i,
887 (unsigned long)bounds[i*2],
888 ~(unsigned long)bounds[i*2+1],
889 (unsigned long)bounds[i*2+1]);
890 }
891
892 eprintf("cpcfg: %jx cpstatus: %jx\n", cfg[0], cfg[1]);
893 }
894 #define print_context(x) __print_context(x, __LINE__)
895 #ifdef DEBUG
896 #define dprint_context(x) print_context(x)
897 #else
898 #define dprint_context(x) do{}while(0)
899 #endif
900
init()901 void init()
902 {
903 int i;
904
905 srand((unsigned int)time(NULL));
906
907 for (i = 0; i < 4; i++) {
908 shadow_plb[i][0] = 0;
909 shadow_plb[i][1] = ~(unsigned long)0;
910 }
911 }
912
__mpx_random(int line)913 long int __mpx_random(int line)
914 {
915 #ifdef NOT_SO_RANDOM
916 static long fake = 722122311;
917 fake += 563792075;
918 return fakse;
919 #else
920 return random();
921 #endif
922 }
923 #define mpx_random() __mpx_random(__LINE__)
924
get_random_addr()925 uint8_t *get_random_addr()
926 {
927 uint8_t*addr = (uint8_t *)(unsigned long)(rand() % MAX_ADDR_TESTED);
928 return (addr - (unsigned long)addr % sizeof(uint8_t *));
929 }
930
compare_context(void * __xsave_buffer)931 static inline bool compare_context(void *__xsave_buffer)
932 {
933 uint64_t *bounds = (uint64_t *)(__xsave_buffer + MPX_BOUNDS_OFFSET);
934
935 int i;
936 for (i = 0; i < 4; i++) {
937 dprintf3("shadow[%d]{%016lx/%016lx}\nbounds[%d]{%016lx/%016lx}\n",
938 i, (unsigned long)shadow_plb[i][0], (unsigned long)shadow_plb[i][1],
939 i, (unsigned long)bounds[i*2], ~(unsigned long)bounds[i*2+1]);
940 if ((shadow_plb[i][0] != bounds[i*2]) ||
941 (shadow_plb[i][1] != ~(unsigned long)bounds[i*2+1])) {
942 eprintf("ERROR comparing shadow to real bound register %d\n", i);
943 eprintf("shadow{0x%016lx/0x%016lx}\nbounds{0x%016lx/0x%016lx}\n",
944 (unsigned long)shadow_plb[i][0], (unsigned long)shadow_plb[i][1],
945 (unsigned long)bounds[i*2], (unsigned long)bounds[i*2+1]);
946 return false;
947 }
948 }
949
950 return true;
951 }
952
mkbnd_shadow(uint8_t * ptr,int index,long offset)953 void mkbnd_shadow(uint8_t *ptr, int index, long offset)
954 {
955 uint64_t *lower = (uint64_t *)&(shadow_plb[index][0]);
956 uint64_t *upper = (uint64_t *)&(shadow_plb[index][1]);
957 *lower = (unsigned long)ptr;
958 *upper = (unsigned long)ptr + offset - 1;
959 }
960
check_lowerbound_shadow(uint8_t * ptr,int index)961 void check_lowerbound_shadow(uint8_t *ptr, int index)
962 {
963 uint64_t *lower = (uint64_t *)&(shadow_plb[index][0]);
964 if (*lower > (uint64_t)(unsigned long)ptr)
965 num_lower_brs++;
966 else
967 dprintf1("LowerBoundChk passed:%p\n", ptr);
968 }
969
check_upperbound_shadow(uint8_t * ptr,int index)970 void check_upperbound_shadow(uint8_t *ptr, int index)
971 {
972 uint64_t upper = *(uint64_t *)&(shadow_plb[index][1]);
973 if (upper < (uint64_t)(unsigned long)ptr)
974 num_upper_brs++;
975 else
976 dprintf1("UpperBoundChk passed:%p\n", ptr);
977 }
978
movbndreg_shadow(int src,int dest)979 __always_inline void movbndreg_shadow(int src, int dest)
980 {
981 shadow_plb[dest][0] = shadow_plb[src][0];
982 shadow_plb[dest][1] = shadow_plb[src][1];
983 }
984
movbnd2mem_shadow(int src,unsigned long * dest)985 __always_inline void movbnd2mem_shadow(int src, unsigned long *dest)
986 {
987 unsigned long *lower = (unsigned long *)&(shadow_plb[src][0]);
988 unsigned long *upper = (unsigned long *)&(shadow_plb[src][1]);
989 *dest = *lower;
990 *(dest+1) = *upper;
991 }
992
movbnd_from_mem_shadow(unsigned long * src,int dest)993 __always_inline void movbnd_from_mem_shadow(unsigned long *src, int dest)
994 {
995 unsigned long *lower = (unsigned long *)&(shadow_plb[dest][0]);
996 unsigned long *upper = (unsigned long *)&(shadow_plb[dest][1]);
997 *lower = *src;
998 *upper = *(src+1);
999 }
1000
stdsc_shadow(int index,uint8_t * ptr,uint8_t * ptr_val)1001 __always_inline void stdsc_shadow(int index, uint8_t *ptr, uint8_t *ptr_val)
1002 {
1003 shadow_map[0] = (unsigned long)shadow_plb[index][0];
1004 shadow_map[1] = (unsigned long)shadow_plb[index][1];
1005 shadow_map[2] = (unsigned long)ptr_val;
1006 dprintf3("%s(%d, %p, %p) set shadow map[2]: %p\n", __func__,
1007 index, ptr, ptr_val, ptr_val);
1008 /*ptr ignored */
1009 }
1010
lddsc_shadow(int index,uint8_t * ptr,uint8_t * ptr_val)1011 void lddsc_shadow(int index, uint8_t *ptr, uint8_t *ptr_val)
1012 {
1013 uint64_t lower = shadow_map[0];
1014 uint64_t upper = shadow_map[1];
1015 uint8_t *value = (uint8_t *)shadow_map[2];
1016
1017 if (value != ptr_val) {
1018 dprintf2("%s(%d, %p, %p) init shadow bounds[%d] "
1019 "because %p != %p\n", __func__, index, ptr,
1020 ptr_val, index, value, ptr_val);
1021 shadow_plb[index][0] = 0;
1022 shadow_plb[index][1] = ~(unsigned long)0;
1023 } else {
1024 shadow_plb[index][0] = lower;
1025 shadow_plb[index][1] = upper;
1026 }
1027 /* ptr ignored */
1028 }
1029
mpx_test_helper0(uint8_t * buf,uint8_t * ptr)1030 static __always_inline void mpx_test_helper0(uint8_t *buf, uint8_t *ptr)
1031 {
1032 mpx_make_bound_helper((unsigned long)ptr, 0x1800);
1033 }
1034
mpx_test_helper0_shadow(uint8_t * buf,uint8_t * ptr)1035 static __always_inline void mpx_test_helper0_shadow(uint8_t *buf, uint8_t *ptr)
1036 {
1037 mkbnd_shadow(ptr, 0, 0x1800);
1038 }
1039
mpx_test_helper1(uint8_t * buf,uint8_t * ptr)1040 static __always_inline void mpx_test_helper1(uint8_t *buf, uint8_t *ptr)
1041 {
1042 /* these are hard-coded to check bnd0 */
1043 expected_bnd_index = 0;
1044 mpx_check_lowerbound_helper((unsigned long)(ptr-1));
1045 mpx_check_upperbound_helper((unsigned long)(ptr+0x1800));
1046 /* reset this since we do not expect any more bounds exceptions */
1047 expected_bnd_index = -1;
1048 }
1049
mpx_test_helper1_shadow(uint8_t * buf,uint8_t * ptr)1050 static __always_inline void mpx_test_helper1_shadow(uint8_t *buf, uint8_t *ptr)
1051 {
1052 check_lowerbound_shadow(ptr-1, 0);
1053 check_upperbound_shadow(ptr+0x1800, 0);
1054 }
1055
mpx_test_helper2(uint8_t * buf,uint8_t * ptr)1056 static __always_inline void mpx_test_helper2(uint8_t *buf, uint8_t *ptr)
1057 {
1058 mpx_make_bound_helper((unsigned long)ptr, 0x1800);
1059 mpx_movbndreg_helper();
1060 mpx_movbnd2mem_helper(buf);
1061 mpx_make_bound_helper((unsigned long)(ptr+0x12), 0x1800);
1062 }
1063
mpx_test_helper2_shadow(uint8_t * buf,uint8_t * ptr)1064 static __always_inline void mpx_test_helper2_shadow(uint8_t *buf, uint8_t *ptr)
1065 {
1066 mkbnd_shadow(ptr, 0, 0x1800);
1067 movbndreg_shadow(0, 2);
1068 movbnd2mem_shadow(0, (unsigned long *)buf);
1069 mkbnd_shadow(ptr+0x12, 0, 0x1800);
1070 }
1071
mpx_test_helper3(uint8_t * buf,uint8_t * ptr)1072 static __always_inline void mpx_test_helper3(uint8_t *buf, uint8_t *ptr)
1073 {
1074 mpx_movbnd_from_mem_helper(buf);
1075 }
1076
mpx_test_helper3_shadow(uint8_t * buf,uint8_t * ptr)1077 static __always_inline void mpx_test_helper3_shadow(uint8_t *buf, uint8_t *ptr)
1078 {
1079 movbnd_from_mem_shadow((unsigned long *)buf, 0);
1080 }
1081
mpx_test_helper4(uint8_t * buf,uint8_t * ptr)1082 static __always_inline void mpx_test_helper4(uint8_t *buf, uint8_t *ptr)
1083 {
1084 mpx_store_dsc_helper((unsigned long)buf, (unsigned long)ptr);
1085 mpx_make_bound_helper((unsigned long)(ptr+0x12), 0x1800);
1086 }
1087
mpx_test_helper4_shadow(uint8_t * buf,uint8_t * ptr)1088 static __always_inline void mpx_test_helper4_shadow(uint8_t *buf, uint8_t *ptr)
1089 {
1090 stdsc_shadow(0, buf, ptr);
1091 mkbnd_shadow(ptr+0x12, 0, 0x1800);
1092 }
1093
mpx_test_helper5(uint8_t * buf,uint8_t * ptr)1094 static __always_inline void mpx_test_helper5(uint8_t *buf, uint8_t *ptr)
1095 {
1096 mpx_load_dsc_helper((unsigned long)buf, (unsigned long)ptr);
1097 }
1098
mpx_test_helper5_shadow(uint8_t * buf,uint8_t * ptr)1099 static __always_inline void mpx_test_helper5_shadow(uint8_t *buf, uint8_t *ptr)
1100 {
1101 lddsc_shadow(0, buf, ptr);
1102 }
1103
1104 #define NR_MPX_TEST_FUNCTIONS 6
1105
1106 /*
1107 * For compatibility reasons, MPX will clear the bounds registers
1108 * when you make function calls (among other things). We have to
1109 * preserve the registers in between calls to the "helpers" since
1110 * they build on each other.
1111 *
1112 * Be very careful not to make any function calls inside the
1113 * helpers, or anywhere else beween the xrstor and xsave.
1114 */
1115 #define run_helper(helper_nr, buf, buf_shadow, ptr) do { \
1116 xrstor_state(xsave_test_buf, flags); \
1117 mpx_test_helper##helper_nr(buf, ptr); \
1118 xsave_state(xsave_test_buf, flags); \
1119 mpx_test_helper##helper_nr##_shadow(buf_shadow, ptr); \
1120 } while (0)
1121
run_helpers(int nr,uint8_t * buf,uint8_t * buf_shadow,uint8_t * ptr)1122 static void run_helpers(int nr, uint8_t *buf, uint8_t *buf_shadow, uint8_t *ptr)
1123 {
1124 uint64_t flags = 0x18;
1125
1126 dprint_context(xsave_test_buf);
1127 switch (nr) {
1128 case 0:
1129 run_helper(0, buf, buf_shadow, ptr);
1130 break;
1131 case 1:
1132 run_helper(1, buf, buf_shadow, ptr);
1133 break;
1134 case 2:
1135 run_helper(2, buf, buf_shadow, ptr);
1136 break;
1137 case 3:
1138 run_helper(3, buf, buf_shadow, ptr);
1139 break;
1140 case 4:
1141 run_helper(4, buf, buf_shadow, ptr);
1142 break;
1143 case 5:
1144 run_helper(5, buf, buf_shadow, ptr);
1145 break;
1146 default:
1147 test_failed();
1148 break;
1149 }
1150 dprint_context(xsave_test_buf);
1151 }
1152
1153 unsigned long buf_shadow[1024]; /* used to check load / store descriptors */
1154 extern long inspect_me(struct mpx_bounds_dir *bounds_dir);
1155
cover_buf_with_bt_entries(void * buf,long buf_len)1156 long cover_buf_with_bt_entries(void *buf, long buf_len)
1157 {
1158 int i;
1159 long nr_to_fill;
1160 int ratio = 1000;
1161 unsigned long buf_len_in_ptrs;
1162
1163 /* Fill about 1/100 of the space with bt entries */
1164 nr_to_fill = buf_len / (sizeof(unsigned long) * ratio);
1165
1166 if (!nr_to_fill)
1167 dprintf3("%s() nr_to_fill: %ld\n", __func__, nr_to_fill);
1168
1169 /* Align the buffer to pointer size */
1170 while (((unsigned long)buf) % sizeof(void *)) {
1171 buf++;
1172 buf_len--;
1173 }
1174 /* We are storing pointers, so make */
1175 buf_len_in_ptrs = buf_len / sizeof(void *);
1176
1177 for (i = 0; i < nr_to_fill; i++) {
1178 long index = (mpx_random() % buf_len_in_ptrs);
1179 void *ptr = buf + index * sizeof(unsigned long);
1180 unsigned long ptr_addr = (unsigned long)ptr;
1181
1182 /* ptr and size can be anything */
1183 mpx_make_bound_helper((unsigned long)ptr, 8);
1184
1185 /*
1186 * take bnd0 and put it in to bounds tables "buf + index" is an
1187 * address inside the buffer where we are pretending that we
1188 * are going to put a pointer We do not, though because we will
1189 * never load entries from the table, so it doesn't matter.
1190 */
1191 mpx_store_dsc_helper(ptr_addr, (unsigned long)ptr);
1192 dprintf4("storing bound table entry for %lx (buf start @ %p)\n",
1193 ptr_addr, buf);
1194 }
1195 return nr_to_fill;
1196 }
1197
align_down(unsigned long alignme,unsigned long align_to)1198 unsigned long align_down(unsigned long alignme, unsigned long align_to)
1199 {
1200 return alignme & ~(align_to-1);
1201 }
1202
align_up(unsigned long alignme,unsigned long align_to)1203 unsigned long align_up(unsigned long alignme, unsigned long align_to)
1204 {
1205 return (alignme + align_to - 1) & ~(align_to-1);
1206 }
1207
1208 /*
1209 * Using 1MB alignment guarantees that each no allocation
1210 * will overlap with another's bounds tables.
1211 *
1212 * We have to cook our own allocator here. malloc() can
1213 * mix other allocation with ours which means that even
1214 * if we free all of our allocations, there might still
1215 * be bounds tables for the *areas* since there is other
1216 * valid memory there.
1217 *
1218 * We also can't use malloc() because a free() of an area
1219 * might not free it back to the kernel. We want it
1220 * completely unmapped an malloc() does not guarantee
1221 * that.
1222 */
1223 #ifdef __i386__
1224 long alignment = 4096;
1225 long sz_alignment = 4096;
1226 #else
1227 long alignment = 1 * MB;
1228 long sz_alignment = 1 * MB;
1229 #endif
mpx_mini_alloc(unsigned long sz)1230 void *mpx_mini_alloc(unsigned long sz)
1231 {
1232 unsigned long long tries = 0;
1233 static void *last;
1234 void *ptr;
1235 void *try_at;
1236
1237 sz = align_up(sz, sz_alignment);
1238
1239 try_at = last + alignment;
1240 while (1) {
1241 ptr = mmap(try_at, sz, PROT_READ|PROT_WRITE,
1242 MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
1243 if (ptr == (void *)-1)
1244 return NULL;
1245 if (ptr == try_at)
1246 break;
1247
1248 munmap(ptr, sz);
1249 try_at += alignment;
1250 #ifdef __i386__
1251 /*
1252 * This isn't quite correct for 32-bit binaries
1253 * on 64-bit kernels since they can use the
1254 * entire 32-bit address space, but it's close
1255 * enough.
1256 */
1257 if (try_at > (void *)0xC0000000)
1258 #else
1259 if (try_at > (void *)0x0000800000000000)
1260 #endif
1261 try_at = (void *)0x0;
1262 if (!(++tries % 10000))
1263 dprintf1("stuck in %s(), tries: %lld\n", __func__, tries);
1264 continue;
1265 }
1266 last = ptr;
1267 dprintf3("mpx_mini_alloc(0x%lx) returning: %p\n", sz, ptr);
1268 return ptr;
1269 }
mpx_mini_free(void * ptr,long sz)1270 void mpx_mini_free(void *ptr, long sz)
1271 {
1272 dprintf2("%s() ptr: %p\n", __func__, ptr);
1273 if ((unsigned long)ptr > 0x100000000000) {
1274 dprintf1("uh oh !!!!!!!!!!!!!!! pointer too high: %p\n", ptr);
1275 test_failed();
1276 }
1277 sz = align_up(sz, sz_alignment);
1278 dprintf3("%s() ptr: %p before munmap\n", __func__, ptr);
1279 munmap(ptr, sz);
1280 dprintf3("%s() ptr: %p DONE\n", __func__, ptr);
1281 }
1282
1283 #define NR_MALLOCS 100
1284 struct one_malloc {
1285 char *ptr;
1286 int nr_filled_btes;
1287 unsigned long size;
1288 };
1289 struct one_malloc mallocs[NR_MALLOCS];
1290
free_one_malloc(int index)1291 void free_one_malloc(int index)
1292 {
1293 unsigned long free_ptr;
1294 unsigned long mask;
1295
1296 if (!mallocs[index].ptr)
1297 return;
1298
1299 mpx_mini_free(mallocs[index].ptr, mallocs[index].size);
1300 dprintf4("freed[%d]: %p\n", index, mallocs[index].ptr);
1301
1302 free_ptr = (unsigned long)mallocs[index].ptr;
1303 mask = alignment-1;
1304 dprintf4("lowerbits: %lx / %lx mask: %lx\n", free_ptr,
1305 (free_ptr & mask), mask);
1306 assert((free_ptr & mask) == 0);
1307
1308 mallocs[index].ptr = NULL;
1309 }
1310
1311 #ifdef __i386__
1312 #define MPX_BOUNDS_TABLE_COVERS 4096
1313 #else
1314 #define MPX_BOUNDS_TABLE_COVERS (1 * MB)
1315 #endif
zap_everything(void)1316 void zap_everything(void)
1317 {
1318 long after_zap;
1319 long before_zap;
1320 int i;
1321
1322 before_zap = inspect_me(bounds_dir_ptr);
1323 dprintf1("zapping everything start: %ld\n", before_zap);
1324 for (i = 0; i < NR_MALLOCS; i++)
1325 free_one_malloc(i);
1326
1327 after_zap = inspect_me(bounds_dir_ptr);
1328 dprintf1("zapping everything done: %ld\n", after_zap);
1329 /*
1330 * We only guarantee to empty the thing out if our allocations are
1331 * exactly aligned on the boundaries of a boudns table.
1332 */
1333 if ((alignment >= MPX_BOUNDS_TABLE_COVERS) &&
1334 (sz_alignment >= MPX_BOUNDS_TABLE_COVERS)) {
1335 if (after_zap != 0)
1336 test_failed();
1337
1338 assert(after_zap == 0);
1339 }
1340 }
1341
do_one_malloc(void)1342 void do_one_malloc(void)
1343 {
1344 static int malloc_counter;
1345 long sz;
1346 int rand_index = (mpx_random() % NR_MALLOCS);
1347 void *ptr = mallocs[rand_index].ptr;
1348
1349 dprintf3("%s() enter\n", __func__);
1350
1351 if (ptr) {
1352 dprintf3("freeing one malloc at index: %d\n", rand_index);
1353 free_one_malloc(rand_index);
1354 if (mpx_random() % (NR_MALLOCS*3) == 3) {
1355 int i;
1356 dprintf3("zapping some more\n");
1357 for (i = rand_index; i < NR_MALLOCS; i++)
1358 free_one_malloc(i);
1359 }
1360 if ((mpx_random() % zap_all_every_this_many_mallocs) == 4)
1361 zap_everything();
1362 }
1363
1364 /* 1->~1M */
1365 sz = (1 + mpx_random() % 1000) * 1000;
1366 ptr = mpx_mini_alloc(sz);
1367 if (!ptr) {
1368 /*
1369 * If we are failing allocations, just assume we
1370 * are out of memory and zap everything.
1371 */
1372 dprintf3("zapping everything because out of memory\n");
1373 zap_everything();
1374 goto out;
1375 }
1376
1377 dprintf3("malloc: %p size: 0x%lx\n", ptr, sz);
1378 mallocs[rand_index].nr_filled_btes = cover_buf_with_bt_entries(ptr, sz);
1379 mallocs[rand_index].ptr = ptr;
1380 mallocs[rand_index].size = sz;
1381 out:
1382 if ((++malloc_counter) % inspect_every_this_many_mallocs == 0)
1383 inspect_me(bounds_dir_ptr);
1384 }
1385
run_timed_test(void (* test_func)(void))1386 void run_timed_test(void (*test_func)(void))
1387 {
1388 int done = 0;
1389 long iteration = 0;
1390 static time_t last_print;
1391 time_t now;
1392 time_t start;
1393
1394 time(&start);
1395 while (!done) {
1396 time(&now);
1397 if ((now - start) > TEST_DURATION_SECS)
1398 done = 1;
1399
1400 test_func();
1401 iteration++;
1402
1403 if ((now - last_print > 1) || done) {
1404 printf("iteration %ld complete, OK so far\n", iteration);
1405 last_print = now;
1406 }
1407 }
1408 }
1409
check_bounds_table_frees(void)1410 void check_bounds_table_frees(void)
1411 {
1412 printf("executing unmaptest\n");
1413 inspect_me(bounds_dir_ptr);
1414 run_timed_test(&do_one_malloc);
1415 printf("done with malloc() fun\n");
1416 }
1417
insn_test_failed(int test_nr,int test_round,void * buf,void * buf_shadow,void * ptr)1418 void insn_test_failed(int test_nr, int test_round, void *buf,
1419 void *buf_shadow, void *ptr)
1420 {
1421 print_context(xsave_test_buf);
1422 eprintf("ERROR: test %d round %d failed\n", test_nr, test_round);
1423 while (test_nr == 5) {
1424 struct mpx_bt_entry *bte;
1425 struct mpx_bounds_dir *bd = (void *)bounds_dir_ptr;
1426 struct mpx_bd_entry *bde = mpx_vaddr_to_bd_entry(buf, bd);
1427
1428 printf(" bd: %p\n", bd);
1429 printf("&bde: %p\n", bde);
1430 printf("*bde: %lx\n", *(unsigned long *)bde);
1431 if (!bd_entry_valid(bde))
1432 break;
1433
1434 bte = mpx_vaddr_to_bt_entry(buf, bd);
1435 printf(" te: %p\n", bte);
1436 printf("bte[0]: %lx\n", bte->contents[0]);
1437 printf("bte[1]: %lx\n", bte->contents[1]);
1438 printf("bte[2]: %lx\n", bte->contents[2]);
1439 printf("bte[3]: %lx\n", bte->contents[3]);
1440 break;
1441 }
1442 test_failed();
1443 }
1444
check_mpx_insns_and_tables(void)1445 void check_mpx_insns_and_tables(void)
1446 {
1447 int successes = 0;
1448 int failures = 0;
1449 int buf_size = (1024*1024);
1450 unsigned long *buf = malloc(buf_size);
1451 const int total_nr_tests = NR_MPX_TEST_FUNCTIONS * TEST_ROUNDS;
1452 int i, j;
1453
1454 memset(buf, 0, buf_size);
1455 memset(buf_shadow, 0, sizeof(buf_shadow));
1456
1457 for (i = 0; i < TEST_ROUNDS; i++) {
1458 uint8_t *ptr = get_random_addr() + 8;
1459
1460 for (j = 0; j < NR_MPX_TEST_FUNCTIONS; j++) {
1461 if (0 && j != 5) {
1462 successes++;
1463 continue;
1464 }
1465 dprintf2("starting test %d round %d\n", j, i);
1466 dprint_context(xsave_test_buf);
1467 /*
1468 * test5 loads an address from the bounds tables.
1469 * The load will only complete if 'ptr' matches
1470 * the load and the store, so with random addrs,
1471 * the odds of this are very small. Make it
1472 * higher by only moving 'ptr' 1/10 times.
1473 */
1474 if (random() % 10 <= 0)
1475 ptr = get_random_addr() + 8;
1476 dprintf3("random ptr{%p}\n", ptr);
1477 dprint_context(xsave_test_buf);
1478 run_helpers(j, (void *)buf, (void *)buf_shadow, ptr);
1479 dprint_context(xsave_test_buf);
1480 if (!compare_context(xsave_test_buf)) {
1481 insn_test_failed(j, i, buf, buf_shadow, ptr);
1482 failures++;
1483 goto exit;
1484 }
1485 successes++;
1486 dprint_context(xsave_test_buf);
1487 dprintf2("finished test %d round %d\n", j, i);
1488 dprintf3("\n");
1489 dprint_context(xsave_test_buf);
1490 }
1491 }
1492
1493 exit:
1494 dprintf2("\nabout to free:\n");
1495 free(buf);
1496 dprintf1("successes: %d\n", successes);
1497 dprintf1(" failures: %d\n", failures);
1498 dprintf1(" tests: %d\n", total_nr_tests);
1499 dprintf1(" expected: %jd #BRs\n", num_upper_brs + num_lower_brs);
1500 dprintf1(" saw: %d #BRs\n", br_count);
1501 if (failures) {
1502 eprintf("ERROR: non-zero number of failures\n");
1503 exit(20);
1504 }
1505 if (successes != total_nr_tests) {
1506 eprintf("ERROR: succeded fewer than number of tries (%d != %d)\n",
1507 successes, total_nr_tests);
1508 exit(21);
1509 }
1510 if (num_upper_brs + num_lower_brs != br_count) {
1511 eprintf("ERROR: unexpected number of #BRs: %jd %jd %d\n",
1512 num_upper_brs, num_lower_brs, br_count);
1513 eprintf("successes: %d\n", successes);
1514 eprintf(" failures: %d\n", failures);
1515 eprintf(" tests: %d\n", total_nr_tests);
1516 eprintf(" expected: %jd #BRs\n", num_upper_brs + num_lower_brs);
1517 eprintf(" saw: %d #BRs\n", br_count);
1518 exit(22);
1519 }
1520 }
1521
1522 /*
1523 * This is supposed to SIGSEGV nicely once the kernel
1524 * can no longer allocate vaddr space.
1525 */
exhaust_vaddr_space(void)1526 void exhaust_vaddr_space(void)
1527 {
1528 unsigned long ptr;
1529 /* Try to make sure there is no room for a bounds table anywhere */
1530 unsigned long skip = MPX_BOUNDS_TABLE_SIZE_BYTES - PAGE_SIZE;
1531 #ifdef __i386__
1532 unsigned long max_vaddr = 0xf7788000UL;
1533 #else
1534 unsigned long max_vaddr = 0x800000000000UL;
1535 #endif
1536
1537 dprintf1("%s() start\n", __func__);
1538 /* do not start at 0, we aren't allowed to map there */
1539 for (ptr = PAGE_SIZE; ptr < max_vaddr; ptr += skip) {
1540 void *ptr_ret;
1541 int ret = madvise((void *)ptr, PAGE_SIZE, MADV_NORMAL);
1542
1543 if (!ret) {
1544 dprintf1("madvise() %lx ret: %d\n", ptr, ret);
1545 continue;
1546 }
1547 ptr_ret = mmap((void *)ptr, PAGE_SIZE, PROT_READ|PROT_WRITE,
1548 MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
1549 if (ptr_ret != (void *)ptr) {
1550 perror("mmap");
1551 dprintf1("mmap(%lx) ret: %p\n", ptr, ptr_ret);
1552 break;
1553 }
1554 if (!(ptr & 0xffffff))
1555 dprintf1("mmap(%lx) ret: %p\n", ptr, ptr_ret);
1556 }
1557 for (ptr = PAGE_SIZE; ptr < max_vaddr; ptr += skip) {
1558 dprintf2("covering 0x%lx with bounds table entries\n", ptr);
1559 cover_buf_with_bt_entries((void *)ptr, PAGE_SIZE);
1560 }
1561 dprintf1("%s() end\n", __func__);
1562 printf("done with vaddr space fun\n");
1563 }
1564
mpx_table_test(void)1565 void mpx_table_test(void)
1566 {
1567 printf("starting mpx bounds table test\n");
1568 run_timed_test(check_mpx_insns_and_tables);
1569 printf("done with mpx bounds table test\n");
1570 }
1571
main(int argc,char ** argv)1572 int main(int argc, char **argv)
1573 {
1574 int unmaptest = 0;
1575 int vaddrexhaust = 0;
1576 int tabletest = 0;
1577 int i;
1578
1579 check_mpx_support();
1580 mpx_prepare();
1581 srandom(11179);
1582
1583 bd_incore();
1584 init();
1585 bd_incore();
1586
1587 trace_me();
1588
1589 xsave_state((void *)xsave_test_buf, 0x1f);
1590 if (!compare_context(xsave_test_buf))
1591 printf("Init failed\n");
1592
1593 for (i = 1; i < argc; i++) {
1594 if (!strcmp(argv[i], "unmaptest"))
1595 unmaptest = 1;
1596 if (!strcmp(argv[i], "vaddrexhaust"))
1597 vaddrexhaust = 1;
1598 if (!strcmp(argv[i], "tabletest"))
1599 tabletest = 1;
1600 }
1601 if (!(unmaptest || vaddrexhaust || tabletest)) {
1602 unmaptest = 1;
1603 /* vaddrexhaust = 1; */
1604 tabletest = 1;
1605 }
1606 if (unmaptest)
1607 check_bounds_table_frees();
1608 if (tabletest)
1609 mpx_table_test();
1610 if (vaddrexhaust)
1611 exhaust_vaddr_space();
1612 printf("%s completed successfully\n", argv[0]);
1613 exit(0);
1614 }
1615
1616 #include "mpx-dig.c"
1617