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