1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Tests Memory Protection Keys (see Documentation/core-api/protection-keys.rst)
4 *
5 * There are examples in here of:
6 * * how to set protection keys on memory
7 * * how to set/clear bits in pkey registers (the rights register)
8 * * how to handle SEGV_PKUERR signals and extract pkey-relevant
9 * information from the siginfo
10 *
11 * Things to add:
12 * make sure KSM and KSM COW breaking works
13 * prefault pages in at malloc, or not
14 * protect MPX bounds tables with protection keys?
15 * make sure VMA splitting/merging is working correctly
16 * OOMs can destroy mm->mmap (see exit_mmap()), so make sure it is immune to pkeys
17 * look for pkey "leaks" where it is still set on a VMA but "freed" back to the kernel
18 * do a plain mprotect() to a mprotect_pkey() area and make sure the pkey sticks
19 *
20 * Compile like this:
21 * gcc -mxsave -o protection_keys -O2 -g -std=gnu99 -pthread -Wall protection_keys.c -lrt -ldl -lm
22 * gcc -mxsave -m32 -o protection_keys_32 -O2 -g -std=gnu99 -pthread -Wall protection_keys.c -lrt -ldl -lm
23 */
24 #define _GNU_SOURCE
25 #define __SANE_USERSPACE_TYPES__
26 #include <errno.h>
27 #include <linux/elf.h>
28 #include <linux/futex.h>
29 #include <time.h>
30 #include <sys/time.h>
31 #include <sys/syscall.h>
32 #include <string.h>
33 #include <stdio.h>
34 #include <stdint.h>
35 #include <stdbool.h>
36 #include <signal.h>
37 #include <assert.h>
38 #include <stdlib.h>
39 #include <ucontext.h>
40 #include <sys/mman.h>
41 #include <sys/types.h>
42 #include <sys/wait.h>
43 #include <sys/stat.h>
44 #include <fcntl.h>
45 #include <asm-generic/unistd.h>
46 #include <sys/ptrace.h>
47 #include <setjmp.h>
48
49 #include "pkey-helpers.h"
50
51 int iteration_nr = 1;
52 int test_nr;
53
54 u64 shadow_pkey_reg;
55 int dprint_in_signal;
56 char dprint_in_signal_buffer[DPRINT_IN_SIGNAL_BUF_SIZE];
57
58 void cat_into_file(char *str, char *file)
59 {
60 int fd = open(file, O_RDWR);
61 int ret;
62
63 dprintf2("%s(): writing '%s' to '%s'\n", __func__, str, file);
64 /*
65 * these need to be raw because they are called under
66 * pkey_assert()
67 */
68 if (fd < 0) {
69 fprintf(stderr, "error opening '%s'\n", str);
70 perror("error: ");
71 exit(__LINE__);
72 }
73
74 ret = write(fd, str, strlen(str));
75 if (ret != strlen(str)) {
76 perror("write to file failed");
77 fprintf(stderr, "filename: '%s' str: '%s'\n", file, str);
78 exit(__LINE__);
79 }
80 close(fd);
81 }
82
83 #if CONTROL_TRACING > 0
84 static int warned_tracing;
85 int tracing_root_ok(void)
86 {
87 if (geteuid() != 0) {
88 if (!warned_tracing)
89 fprintf(stderr, "WARNING: not run as root, "
90 "can not do tracing control\n");
91 warned_tracing = 1;
92 return 0;
93 }
94 return 1;
95 }
96 #endif
97
98 void tracing_on(void)
99 {
100 #if CONTROL_TRACING > 0
101 #define TRACEDIR "/sys/kernel/tracing"
102 char pidstr[32];
103
104 if (!tracing_root_ok())
105 return;
106
107 sprintf(pidstr, "%d", getpid());
108 cat_into_file("", TRACEDIR "/tracing_on");
109 cat_into_file("\n", TRACEDIR "/trace");
110 if (1) {
111 cat_into_file("function_graph", TRACEDIR "/current_tracer");
112 cat_into_file("1", TRACEDIR "/options/funcgraph-proc");
113 } else {
114 cat_into_file("nop", TRACEDIR "/current_tracer");
115 }
116 cat_into_file(pidstr, TRACEDIR "/set_ftrace_pid");
117 cat_into_file("1", TRACEDIR "/tracing_on");
118 dprintf1("enabled tracing\n");
119 #endif
120 }
121
122 void tracing_off(void)
123 {
124 #if CONTROL_TRACING > 0
125 if (!tracing_root_ok())
126 return;
127 cat_into_file("", "/sys/kernel/tracing/tracing_on");
128 #endif
129 }
130
131 void abort_hooks(void)
132 {
133 fprintf(stderr, "running %s()...\n", __func__);
134 tracing_off();
135 #ifdef SLEEP_ON_ABORT
136 sleep(SLEEP_ON_ABORT);
137 #endif
138 }
139
140 /*
141 * This attempts to have roughly a page of instructions followed by a few
142 * instructions that do a write, and another page of instructions. That
143 * way, we are pretty sure that the write is in the second page of
144 * instructions and has at least a page of padding behind it.
145 *
146 * *That* lets us be sure to madvise() away the write instruction, which
147 * will then fault, which makes sure that the fault code handles
148 * execute-only memory properly.
149 */
150 #ifdef __powerpc64__
151 /* This way, both 4K and 64K alignment are maintained */
152 __attribute__((__aligned__(65536)))
153 #else
154 __attribute__((__aligned__(PAGE_SIZE)))
155 #endif
156 void lots_o_noops_around_write(int *write_to_me)
157 {
158 dprintf3("running %s()\n", __func__);
159 __page_o_noops();
160 /* Assume this happens in the second page of instructions: */
161 *write_to_me = __LINE__;
162 /* pad out by another page: */
163 __page_o_noops();
164 dprintf3("%s() done\n", __func__);
165 }
166
167 void dump_mem(void *dumpme, int len_bytes)
168 {
169 char *c = (void *)dumpme;
170 int i;
171
172 for (i = 0; i < len_bytes; i += sizeof(u64)) {
173 u64 *ptr = (u64 *)(c + i);
174 dprintf1("dump[%03d][@%p]: %016llx\n", i, ptr, *ptr);
175 }
176 }
177
178 static u32 hw_pkey_get(int pkey, unsigned long flags)
179 {
180 u64 pkey_reg = __read_pkey_reg();
181
182 dprintf1("%s(pkey=%d, flags=%lx) = %x / %d\n",
183 __func__, pkey, flags, 0, 0);
184 dprintf2("%s() raw pkey_reg: %016llx\n", __func__, pkey_reg);
185
186 return (u32) get_pkey_bits(pkey_reg, pkey);
187 }
188
189 static int hw_pkey_set(int pkey, unsigned long rights, unsigned long flags)
190 {
191 u32 mask = (PKEY_DISABLE_ACCESS|PKEY_DISABLE_WRITE);
192 u64 old_pkey_reg = __read_pkey_reg();
193 u64 new_pkey_reg;
194
195 /* make sure that 'rights' only contains the bits we expect: */
196 assert(!(rights & ~mask));
197
198 /* modify bits accordingly in old pkey_reg and assign it */
199 new_pkey_reg = set_pkey_bits(old_pkey_reg, pkey, rights);
200
201 __write_pkey_reg(new_pkey_reg);
202
203 dprintf3("%s(pkey=%d, rights=%lx, flags=%lx) = %x"
204 " pkey_reg now: %016llx old_pkey_reg: %016llx\n",
205 __func__, pkey, rights, flags, 0, __read_pkey_reg(),
206 old_pkey_reg);
207 return 0;
208 }
209
210 void pkey_disable_set(int pkey, int flags)
211 {
212 unsigned long syscall_flags = 0;
213 int ret;
214 int pkey_rights;
215 u64 orig_pkey_reg = read_pkey_reg();
216
217 dprintf1("START->%s(%d, 0x%x)\n", __func__,
218 pkey, flags);
219 pkey_assert(flags & (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE));
220
221 pkey_rights = hw_pkey_get(pkey, syscall_flags);
222
223 dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
224 pkey, pkey, pkey_rights);
225
226 pkey_assert(pkey_rights >= 0);
227
228 pkey_rights |= flags;
229
230 ret = hw_pkey_set(pkey, pkey_rights, syscall_flags);
231 assert(!ret);
232 /* pkey_reg and flags have the same format */
233 shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, pkey, pkey_rights);
234 dprintf1("%s(%d) shadow: 0x%016llx\n",
235 __func__, pkey, shadow_pkey_reg);
236
237 pkey_assert(ret >= 0);
238
239 pkey_rights = hw_pkey_get(pkey, syscall_flags);
240 dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
241 pkey, pkey, pkey_rights);
242
243 dprintf1("%s(%d) pkey_reg: 0x%016llx\n",
244 __func__, pkey, read_pkey_reg());
245 if (flags)
246 pkey_assert(read_pkey_reg() >= orig_pkey_reg);
247 dprintf1("END<---%s(%d, 0x%x)\n", __func__,
248 pkey, flags);
249 }
250
251 void pkey_disable_clear(int pkey, int flags)
252 {
253 unsigned long syscall_flags = 0;
254 int ret;
255 int pkey_rights = hw_pkey_get(pkey, syscall_flags);
256 u64 orig_pkey_reg = read_pkey_reg();
257
258 pkey_assert(flags & (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE));
259
260 dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
261 pkey, pkey, pkey_rights);
262 pkey_assert(pkey_rights >= 0);
263
264 pkey_rights &= ~flags;
265
266 ret = hw_pkey_set(pkey, pkey_rights, 0);
267 shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, pkey, pkey_rights);
268 pkey_assert(ret >= 0);
269
270 pkey_rights = hw_pkey_get(pkey, syscall_flags);
271 dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
272 pkey, pkey, pkey_rights);
273
274 dprintf1("%s(%d) pkey_reg: 0x%016llx\n", __func__,
275 pkey, read_pkey_reg());
276 if (flags)
277 assert(read_pkey_reg() <= orig_pkey_reg);
278 }
279
280 void pkey_write_allow(int pkey)
281 {
282 pkey_disable_clear(pkey, PKEY_DISABLE_WRITE);
283 }
284 void pkey_write_deny(int pkey)
285 {
286 pkey_disable_set(pkey, PKEY_DISABLE_WRITE);
287 }
288 void pkey_access_allow(int pkey)
289 {
290 pkey_disable_clear(pkey, PKEY_DISABLE_ACCESS);
291 }
292 void pkey_access_deny(int pkey)
293 {
294 pkey_disable_set(pkey, PKEY_DISABLE_ACCESS);
295 }
296
297 static char *si_code_str(int si_code)
298 {
299 if (si_code == SEGV_MAPERR)
300 return "SEGV_MAPERR";
301 if (si_code == SEGV_ACCERR)
302 return "SEGV_ACCERR";
303 if (si_code == SEGV_BNDERR)
304 return "SEGV_BNDERR";
305 if (si_code == SEGV_PKUERR)
306 return "SEGV_PKUERR";
307 return "UNKNOWN";
308 }
309
310 int pkey_faults;
311 int last_si_pkey = -1;
312 void signal_handler(int signum, siginfo_t *si, void *vucontext)
313 {
314 ucontext_t *uctxt = vucontext;
315 int trapno;
316 unsigned long ip;
317 char *fpregs;
318 #if defined(__i386__) || defined(__x86_64__) /* arch */
319 u32 *pkey_reg_ptr;
320 int pkey_reg_offset;
321 #endif /* arch */
322 u64 siginfo_pkey;
323 u32 *si_pkey_ptr;
324
325 dprint_in_signal = 1;
326 dprintf1(">>>>===============SIGSEGV============================\n");
327 dprintf1("%s()::%d, pkey_reg: 0x%016llx shadow: %016llx\n",
328 __func__, __LINE__,
329 __read_pkey_reg(), shadow_pkey_reg);
330
331 trapno = uctxt->uc_mcontext.gregs[REG_TRAPNO];
332 ip = uctxt->uc_mcontext.gregs[REG_IP_IDX];
333 fpregs = (char *) uctxt->uc_mcontext.fpregs;
334
335 dprintf2("%s() trapno: %d ip: 0x%016lx info->si_code: %s/%d\n",
336 __func__, trapno, ip, si_code_str(si->si_code),
337 si->si_code);
338
339 #if defined(__i386__) || defined(__x86_64__) /* arch */
340 #ifdef __i386__
341 /*
342 * 32-bit has some extra padding so that userspace can tell whether
343 * the XSTATE header is present in addition to the "legacy" FPU
344 * state. We just assume that it is here.
345 */
346 fpregs += 0x70;
347 #endif /* i386 */
348 pkey_reg_offset = pkey_reg_xstate_offset();
349 pkey_reg_ptr = (void *)(&fpregs[pkey_reg_offset]);
350
351 /*
352 * If we got a PKEY fault, we *HAVE* to have at least one bit set in
353 * here.
354 */
355 dprintf1("pkey_reg_xstate_offset: %d\n", pkey_reg_xstate_offset());
356 if (DEBUG_LEVEL > 4)
357 dump_mem(pkey_reg_ptr - 128, 256);
358 pkey_assert(*pkey_reg_ptr);
359 #endif /* arch */
360
361 dprintf1("siginfo: %p\n", si);
362 dprintf1(" fpregs: %p\n", fpregs);
363
364 if ((si->si_code == SEGV_MAPERR) ||
365 (si->si_code == SEGV_ACCERR) ||
366 (si->si_code == SEGV_BNDERR)) {
367 printf("non-PK si_code, exiting...\n");
368 exit(4);
369 }
370
371 si_pkey_ptr = siginfo_get_pkey_ptr(si);
372 dprintf1("si_pkey_ptr: %p\n", si_pkey_ptr);
373 dump_mem((u8 *)si_pkey_ptr - 8, 24);
374 siginfo_pkey = *si_pkey_ptr;
375 pkey_assert(siginfo_pkey < NR_PKEYS);
376 last_si_pkey = siginfo_pkey;
377
378 /*
379 * need __read_pkey_reg() version so we do not do shadow_pkey_reg
380 * checking
381 */
382 dprintf1("signal pkey_reg from pkey_reg: %016llx\n",
383 __read_pkey_reg());
384 dprintf1("pkey from siginfo: %016llx\n", siginfo_pkey);
385 #if defined(__i386__) || defined(__x86_64__) /* arch */
386 dprintf1("signal pkey_reg from xsave: %08x\n", *pkey_reg_ptr);
387 *(u64 *)pkey_reg_ptr = 0x00000000;
388 dprintf1("WARNING: set PKEY_REG=0 to allow faulting instruction to continue\n");
389 #elif defined(__powerpc64__) /* arch */
390 /* restore access and let the faulting instruction continue */
391 pkey_access_allow(siginfo_pkey);
392 #endif /* arch */
393 pkey_faults++;
394 dprintf1("<<<<==================================================\n");
395 dprint_in_signal = 0;
396 }
397
398 int wait_all_children(void)
399 {
400 int status;
401 return waitpid(-1, &status, 0);
402 }
403
404 void sig_chld(int x)
405 {
406 dprint_in_signal = 1;
407 dprintf2("[%d] SIGCHLD: %d\n", getpid(), x);
408 dprint_in_signal = 0;
409 }
410
411 void setup_sigsegv_handler(void)
412 {
413 int r, rs;
414 struct sigaction newact;
415 struct sigaction oldact;
416
417 /* #PF is mapped to sigsegv */
418 int signum = SIGSEGV;
419
420 newact.sa_handler = 0;
421 newact.sa_sigaction = signal_handler;
422
423 /*sigset_t - signals to block while in the handler */
424 /* get the old signal mask. */
425 rs = sigprocmask(SIG_SETMASK, 0, &newact.sa_mask);
426 pkey_assert(rs == 0);
427
428 /* call sa_sigaction, not sa_handler*/
429 newact.sa_flags = SA_SIGINFO;
430
431 newact.sa_restorer = 0; /* void(*)(), obsolete */
432 r = sigaction(signum, &newact, &oldact);
433 r = sigaction(SIGALRM, &newact, &oldact);
434 pkey_assert(r == 0);
435 }
436
437 void setup_handlers(void)
438 {
439 signal(SIGCHLD, &sig_chld);
440 setup_sigsegv_handler();
441 }
442
443 pid_t fork_lazy_child(void)
444 {
445 pid_t forkret;
446
447 forkret = fork();
448 pkey_assert(forkret >= 0);
449 dprintf3("[%d] fork() ret: %d\n", getpid(), forkret);
450
451 if (!forkret) {
452 /* in the child */
453 while (1) {
454 dprintf1("child sleeping...\n");
455 sleep(30);
456 }
457 }
458 return forkret;
459 }
460
461 int sys_mprotect_pkey(void *ptr, size_t size, unsigned long orig_prot,
462 unsigned long pkey)
463 {
464 int sret;
465
466 dprintf2("%s(0x%p, %zx, prot=%lx, pkey=%lx)\n", __func__,
467 ptr, size, orig_prot, pkey);
468
469 errno = 0;
470 sret = syscall(__NR_pkey_mprotect, ptr, size, orig_prot, pkey);
471 if (errno) {
472 dprintf2("SYS_mprotect_key sret: %d\n", sret);
473 dprintf2("SYS_mprotect_key prot: 0x%lx\n", orig_prot);
474 dprintf2("SYS_mprotect_key failed, errno: %d\n", errno);
475 if (DEBUG_LEVEL >= 2)
476 perror("SYS_mprotect_pkey");
477 }
478 return sret;
479 }
480
481 int sys_pkey_alloc(unsigned long flags, unsigned long init_val)
482 {
483 int ret = syscall(SYS_pkey_alloc, flags, init_val);
484 dprintf1("%s(flags=%lx, init_val=%lx) syscall ret: %d errno: %d\n",
485 __func__, flags, init_val, ret, errno);
486 return ret;
487 }
488
489 int alloc_pkey(void)
490 {
491 int ret;
492 unsigned long init_val = 0x0;
493
494 dprintf1("%s()::%d, pkey_reg: 0x%016llx shadow: %016llx\n",
495 __func__, __LINE__, __read_pkey_reg(), shadow_pkey_reg);
496 ret = sys_pkey_alloc(0, init_val);
497 /*
498 * pkey_alloc() sets PKEY register, so we need to reflect it in
499 * shadow_pkey_reg:
500 */
501 dprintf4("%s()::%d, ret: %d pkey_reg: 0x%016llx"
502 " shadow: 0x%016llx\n",
503 __func__, __LINE__, ret, __read_pkey_reg(),
504 shadow_pkey_reg);
505 if (ret > 0) {
506 /* clear both the bits: */
507 shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, ret,
508 ~PKEY_MASK);
509 dprintf4("%s()::%d, ret: %d pkey_reg: 0x%016llx"
510 " shadow: 0x%016llx\n",
511 __func__,
512 __LINE__, ret, __read_pkey_reg(),
513 shadow_pkey_reg);
514 /*
515 * move the new state in from init_val
516 * (remember, we cheated and init_val == pkey_reg format)
517 */
518 shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, ret,
519 init_val);
520 }
521 dprintf4("%s()::%d, ret: %d pkey_reg: 0x%016llx"
522 " shadow: 0x%016llx\n",
523 __func__, __LINE__, ret, __read_pkey_reg(),
524 shadow_pkey_reg);
525 dprintf1("%s()::%d errno: %d\n", __func__, __LINE__, errno);
526 /* for shadow checking: */
527 read_pkey_reg();
528 dprintf4("%s()::%d, ret: %d pkey_reg: 0x%016llx"
529 " shadow: 0x%016llx\n",
530 __func__, __LINE__, ret, __read_pkey_reg(),
531 shadow_pkey_reg);
532 return ret;
533 }
534
535 int sys_pkey_free(unsigned long pkey)
536 {
537 int ret = syscall(SYS_pkey_free, pkey);
538 dprintf1("%s(pkey=%ld) syscall ret: %d\n", __func__, pkey, ret);
539 return ret;
540 }
541
542 /*
543 * I had a bug where pkey bits could be set by mprotect() but
544 * not cleared. This ensures we get lots of random bit sets
545 * and clears on the vma and pte pkey bits.
546 */
547 int alloc_random_pkey(void)
548 {
549 int max_nr_pkey_allocs;
550 int ret;
551 int i;
552 int alloced_pkeys[NR_PKEYS];
553 int nr_alloced = 0;
554 int random_index;
555 memset(alloced_pkeys, 0, sizeof(alloced_pkeys));
556
557 /* allocate every possible key and make a note of which ones we got */
558 max_nr_pkey_allocs = NR_PKEYS;
559 for (i = 0; i < max_nr_pkey_allocs; i++) {
560 int new_pkey = alloc_pkey();
561 if (new_pkey < 0)
562 break;
563 alloced_pkeys[nr_alloced++] = new_pkey;
564 }
565
566 pkey_assert(nr_alloced > 0);
567 /* select a random one out of the allocated ones */
568 random_index = rand() % nr_alloced;
569 ret = alloced_pkeys[random_index];
570 /* now zero it out so we don't free it next */
571 alloced_pkeys[random_index] = 0;
572
573 /* go through the allocated ones that we did not want and free them */
574 for (i = 0; i < nr_alloced; i++) {
575 int free_ret;
576 if (!alloced_pkeys[i])
577 continue;
578 free_ret = sys_pkey_free(alloced_pkeys[i]);
579 pkey_assert(!free_ret);
580 }
581 dprintf1("%s()::%d, ret: %d pkey_reg: 0x%016llx"
582 " shadow: 0x%016llx\n", __func__,
583 __LINE__, ret, __read_pkey_reg(), shadow_pkey_reg);
584 return ret;
585 }
586
587 int mprotect_pkey(void *ptr, size_t size, unsigned long orig_prot,
588 unsigned long pkey)
589 {
590 int nr_iterations = random() % 100;
591 int ret;
592
593 while (0) {
594 int rpkey = alloc_random_pkey();
595 ret = sys_mprotect_pkey(ptr, size, orig_prot, pkey);
596 dprintf1("sys_mprotect_pkey(%p, %zx, prot=0x%lx, pkey=%ld) ret: %d\n",
597 ptr, size, orig_prot, pkey, ret);
598 if (nr_iterations-- < 0)
599 break;
600
601 dprintf1("%s()::%d, ret: %d pkey_reg: 0x%016llx"
602 " shadow: 0x%016llx\n",
603 __func__, __LINE__, ret, __read_pkey_reg(),
604 shadow_pkey_reg);
605 sys_pkey_free(rpkey);
606 dprintf1("%s()::%d, ret: %d pkey_reg: 0x%016llx"
607 " shadow: 0x%016llx\n",
608 __func__, __LINE__, ret, __read_pkey_reg(),
609 shadow_pkey_reg);
610 }
611 pkey_assert(pkey < NR_PKEYS);
612
613 ret = sys_mprotect_pkey(ptr, size, orig_prot, pkey);
614 dprintf1("mprotect_pkey(%p, %zx, prot=0x%lx, pkey=%ld) ret: %d\n",
615 ptr, size, orig_prot, pkey, ret);
616 pkey_assert(!ret);
617 dprintf1("%s()::%d, ret: %d pkey_reg: 0x%016llx"
618 " shadow: 0x%016llx\n", __func__,
619 __LINE__, ret, __read_pkey_reg(), shadow_pkey_reg);
620 return ret;
621 }
622
623 struct pkey_malloc_record {
624 void *ptr;
625 long size;
626 int prot;
627 };
628 struct pkey_malloc_record *pkey_malloc_records;
629 struct pkey_malloc_record *pkey_last_malloc_record;
630 long nr_pkey_malloc_records;
631 void record_pkey_malloc(void *ptr, long size, int prot)
632 {
633 long i;
634 struct pkey_malloc_record *rec = NULL;
635
636 for (i = 0; i < nr_pkey_malloc_records; i++) {
637 rec = &pkey_malloc_records[i];
638 /* find a free record */
639 if (rec)
640 break;
641 }
642 if (!rec) {
643 /* every record is full */
644 size_t old_nr_records = nr_pkey_malloc_records;
645 size_t new_nr_records = (nr_pkey_malloc_records * 2 + 1);
646 size_t new_size = new_nr_records * sizeof(struct pkey_malloc_record);
647 dprintf2("new_nr_records: %zd\n", new_nr_records);
648 dprintf2("new_size: %zd\n", new_size);
649 pkey_malloc_records = realloc(pkey_malloc_records, new_size);
650 pkey_assert(pkey_malloc_records != NULL);
651 rec = &pkey_malloc_records[nr_pkey_malloc_records];
652 /*
653 * realloc() does not initialize memory, so zero it from
654 * the first new record all the way to the end.
655 */
656 for (i = 0; i < new_nr_records - old_nr_records; i++)
657 memset(rec + i, 0, sizeof(*rec));
658 }
659 dprintf3("filling malloc record[%d/%p]: {%p, %ld}\n",
660 (int)(rec - pkey_malloc_records), rec, ptr, size);
661 rec->ptr = ptr;
662 rec->size = size;
663 rec->prot = prot;
664 pkey_last_malloc_record = rec;
665 nr_pkey_malloc_records++;
666 }
667
668 void free_pkey_malloc(void *ptr)
669 {
670 long i;
671 int ret;
672 dprintf3("%s(%p)\n", __func__, ptr);
673 for (i = 0; i < nr_pkey_malloc_records; i++) {
674 struct pkey_malloc_record *rec = &pkey_malloc_records[i];
675 dprintf4("looking for ptr %p at record[%ld/%p]: {%p, %ld}\n",
676 ptr, i, rec, rec->ptr, rec->size);
677 if ((ptr < rec->ptr) ||
678 (ptr >= rec->ptr + rec->size))
679 continue;
680
681 dprintf3("found ptr %p at record[%ld/%p]: {%p, %ld}\n",
682 ptr, i, rec, rec->ptr, rec->size);
683 nr_pkey_malloc_records--;
684 ret = munmap(rec->ptr, rec->size);
685 dprintf3("munmap ret: %d\n", ret);
686 pkey_assert(!ret);
687 dprintf3("clearing rec->ptr, rec: %p\n", rec);
688 rec->ptr = NULL;
689 dprintf3("done clearing rec->ptr, rec: %p\n", rec);
690 return;
691 }
692 pkey_assert(false);
693 }
694
695
696 void *malloc_pkey_with_mprotect(long size, int prot, u16 pkey)
697 {
698 void *ptr;
699 int ret;
700
701 read_pkey_reg();
702 dprintf1("doing %s(size=%ld, prot=0x%x, pkey=%d)\n", __func__,
703 size, prot, pkey);
704 pkey_assert(pkey < NR_PKEYS);
705 ptr = mmap(NULL, size, prot, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
706 pkey_assert(ptr != (void *)-1);
707 ret = mprotect_pkey((void *)ptr, PAGE_SIZE, prot, pkey);
708 pkey_assert(!ret);
709 record_pkey_malloc(ptr, size, prot);
710 read_pkey_reg();
711
712 dprintf1("%s() for pkey %d @ %p\n", __func__, pkey, ptr);
713 return ptr;
714 }
715
716 void *malloc_pkey_anon_huge(long size, int prot, u16 pkey)
717 {
718 int ret;
719 void *ptr;
720
721 dprintf1("doing %s(size=%ld, prot=0x%x, pkey=%d)\n", __func__,
722 size, prot, pkey);
723 /*
724 * Guarantee we can fit at least one huge page in the resulting
725 * allocation by allocating space for 2:
726 */
727 size = ALIGN_UP(size, HPAGE_SIZE * 2);
728 ptr = mmap(NULL, size, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
729 pkey_assert(ptr != (void *)-1);
730 record_pkey_malloc(ptr, size, prot);
731 mprotect_pkey(ptr, size, prot, pkey);
732
733 dprintf1("unaligned ptr: %p\n", ptr);
734 ptr = ALIGN_PTR_UP(ptr, HPAGE_SIZE);
735 dprintf1(" aligned ptr: %p\n", ptr);
736 ret = madvise(ptr, HPAGE_SIZE, MADV_HUGEPAGE);
737 dprintf1("MADV_HUGEPAGE ret: %d\n", ret);
738 ret = madvise(ptr, HPAGE_SIZE, MADV_WILLNEED);
739 dprintf1("MADV_WILLNEED ret: %d\n", ret);
740 memset(ptr, 0, HPAGE_SIZE);
741
742 dprintf1("mmap()'d thp for pkey %d @ %p\n", pkey, ptr);
743 return ptr;
744 }
745
746 int hugetlb_setup_ok;
747 #define SYSFS_FMT_NR_HUGE_PAGES "/sys/kernel/mm/hugepages/hugepages-%ldkB/nr_hugepages"
748 #define GET_NR_HUGE_PAGES 10
749 void setup_hugetlbfs(void)
750 {
751 int err;
752 int fd;
753 char buf[256];
754 long hpagesz_kb;
755 long hpagesz_mb;
756
757 if (geteuid() != 0) {
758 fprintf(stderr, "WARNING: not run as root, can not do hugetlb test\n");
759 return;
760 }
761
762 cat_into_file(__stringify(GET_NR_HUGE_PAGES), "/proc/sys/vm/nr_hugepages");
763
764 /*
765 * Now go make sure that we got the pages and that they
766 * are PMD-level pages. Someone might have made PUD-level
767 * pages the default.
768 */
769 hpagesz_kb = HPAGE_SIZE / 1024;
770 hpagesz_mb = hpagesz_kb / 1024;
771 sprintf(buf, SYSFS_FMT_NR_HUGE_PAGES, hpagesz_kb);
772 fd = open(buf, O_RDONLY);
773 if (fd < 0) {
774 fprintf(stderr, "opening sysfs %ldM hugetlb config: %s\n",
775 hpagesz_mb, strerror(errno));
776 return;
777 }
778
779 /* -1 to guarantee leaving the trailing \0 */
780 err = read(fd, buf, sizeof(buf)-1);
781 close(fd);
782 if (err <= 0) {
783 fprintf(stderr, "reading sysfs %ldM hugetlb config: %s\n",
784 hpagesz_mb, strerror(errno));
785 return;
786 }
787
788 if (atoi(buf) != GET_NR_HUGE_PAGES) {
789 fprintf(stderr, "could not confirm %ldM pages, got: '%s' expected %d\n",
790 hpagesz_mb, buf, GET_NR_HUGE_PAGES);
791 return;
792 }
793
794 hugetlb_setup_ok = 1;
795 }
796
797 void *malloc_pkey_hugetlb(long size, int prot, u16 pkey)
798 {
799 void *ptr;
800 int flags = MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB;
801
802 if (!hugetlb_setup_ok)
803 return PTR_ERR_ENOTSUP;
804
805 dprintf1("doing %s(%ld, %x, %x)\n", __func__, size, prot, pkey);
806 size = ALIGN_UP(size, HPAGE_SIZE * 2);
807 pkey_assert(pkey < NR_PKEYS);
808 ptr = mmap(NULL, size, PROT_NONE, flags, -1, 0);
809 pkey_assert(ptr != (void *)-1);
810 mprotect_pkey(ptr, size, prot, pkey);
811
812 record_pkey_malloc(ptr, size, prot);
813
814 dprintf1("mmap()'d hugetlbfs for pkey %d @ %p\n", pkey, ptr);
815 return ptr;
816 }
817
818 void *malloc_pkey_mmap_dax(long size, int prot, u16 pkey)
819 {
820 void *ptr;
821 int fd;
822
823 dprintf1("doing %s(size=%ld, prot=0x%x, pkey=%d)\n", __func__,
824 size, prot, pkey);
825 pkey_assert(pkey < NR_PKEYS);
826 fd = open("/dax/foo", O_RDWR);
827 pkey_assert(fd >= 0);
828
829 ptr = mmap(0, size, prot, MAP_SHARED, fd, 0);
830 pkey_assert(ptr != (void *)-1);
831
832 mprotect_pkey(ptr, size, prot, pkey);
833
834 record_pkey_malloc(ptr, size, prot);
835
836 dprintf1("mmap()'d for pkey %d @ %p\n", pkey, ptr);
837 close(fd);
838 return ptr;
839 }
840
841 void *(*pkey_malloc[])(long size, int prot, u16 pkey) = {
842
843 malloc_pkey_with_mprotect,
844 malloc_pkey_with_mprotect_subpage,
845 malloc_pkey_anon_huge,
846 malloc_pkey_hugetlb
847 /* can not do direct with the pkey_mprotect() API:
848 malloc_pkey_mmap_direct,
849 malloc_pkey_mmap_dax,
850 */
851 };
852
853 void *malloc_pkey(long size, int prot, u16 pkey)
854 {
855 void *ret;
856 static int malloc_type;
857 int nr_malloc_types = ARRAY_SIZE(pkey_malloc);
858
859 pkey_assert(pkey < NR_PKEYS);
860
861 while (1) {
862 pkey_assert(malloc_type < nr_malloc_types);
863
864 ret = pkey_malloc[malloc_type](size, prot, pkey);
865 pkey_assert(ret != (void *)-1);
866
867 malloc_type++;
868 if (malloc_type >= nr_malloc_types)
869 malloc_type = (random()%nr_malloc_types);
870
871 /* try again if the malloc_type we tried is unsupported */
872 if (ret == PTR_ERR_ENOTSUP)
873 continue;
874
875 break;
876 }
877
878 dprintf3("%s(%ld, prot=%x, pkey=%x) returning: %p\n", __func__,
879 size, prot, pkey, ret);
880 return ret;
881 }
882
883 int last_pkey_faults;
884 #define UNKNOWN_PKEY -2
885 void expected_pkey_fault(int pkey)
886 {
887 dprintf2("%s(): last_pkey_faults: %d pkey_faults: %d\n",
888 __func__, last_pkey_faults, pkey_faults);
889 dprintf2("%s(%d): last_si_pkey: %d\n", __func__, pkey, last_si_pkey);
890 pkey_assert(last_pkey_faults + 1 == pkey_faults);
891
892 /*
893 * For exec-only memory, we do not know the pkey in
894 * advance, so skip this check.
895 */
896 if (pkey != UNKNOWN_PKEY)
897 pkey_assert(last_si_pkey == pkey);
898
899 #if defined(__i386__) || defined(__x86_64__) /* arch */
900 /*
901 * The signal handler shold have cleared out PKEY register to let the
902 * test program continue. We now have to restore it.
903 */
904 if (__read_pkey_reg() != 0)
905 #else /* arch */
906 if (__read_pkey_reg() != shadow_pkey_reg)
907 #endif /* arch */
908 pkey_assert(0);
909
910 __write_pkey_reg(shadow_pkey_reg);
911 dprintf1("%s() set pkey_reg=%016llx to restore state after signal "
912 "nuked it\n", __func__, shadow_pkey_reg);
913 last_pkey_faults = pkey_faults;
914 last_si_pkey = -1;
915 }
916
917 #define do_not_expect_pkey_fault(msg) do { \
918 if (last_pkey_faults != pkey_faults) \
919 dprintf0("unexpected PKey fault: %s\n", msg); \
920 pkey_assert(last_pkey_faults == pkey_faults); \
921 } while (0)
922
923 int test_fds[10] = { -1 };
924 int nr_test_fds;
925 void __save_test_fd(int fd)
926 {
927 pkey_assert(fd >= 0);
928 pkey_assert(nr_test_fds < ARRAY_SIZE(test_fds));
929 test_fds[nr_test_fds] = fd;
930 nr_test_fds++;
931 }
932
933 int get_test_read_fd(void)
934 {
935 int test_fd = open("/etc/passwd", O_RDONLY);
936 __save_test_fd(test_fd);
937 return test_fd;
938 }
939
940 void close_test_fds(void)
941 {
942 int i;
943
944 for (i = 0; i < nr_test_fds; i++) {
945 if (test_fds[i] < 0)
946 continue;
947 close(test_fds[i]);
948 test_fds[i] = -1;
949 }
950 nr_test_fds = 0;
951 }
952
953 #define barrier() __asm__ __volatile__("": : :"memory")
954 __attribute__((noinline)) int read_ptr(int *ptr)
955 {
956 /*
957 * Keep GCC from optimizing this away somehow
958 */
959 barrier();
960 return *ptr;
961 }
962
963 void test_pkey_alloc_free_attach_pkey0(int *ptr, u16 pkey)
964 {
965 int i, err;
966 int max_nr_pkey_allocs;
967 int alloced_pkeys[NR_PKEYS];
968 int nr_alloced = 0;
969 long size;
970
971 pkey_assert(pkey_last_malloc_record);
972 size = pkey_last_malloc_record->size;
973 /*
974 * This is a bit of a hack. But mprotect() requires
975 * huge-page-aligned sizes when operating on hugetlbfs.
976 * So, make sure that we use something that's a multiple
977 * of a huge page when we can.
978 */
979 if (size >= HPAGE_SIZE)
980 size = HPAGE_SIZE;
981
982 /* allocate every possible key and make sure key-0 never got allocated */
983 max_nr_pkey_allocs = NR_PKEYS;
984 for (i = 0; i < max_nr_pkey_allocs; i++) {
985 int new_pkey = alloc_pkey();
986 pkey_assert(new_pkey != 0);
987
988 if (new_pkey < 0)
989 break;
990 alloced_pkeys[nr_alloced++] = new_pkey;
991 }
992 /* free all the allocated keys */
993 for (i = 0; i < nr_alloced; i++) {
994 int free_ret;
995
996 if (!alloced_pkeys[i])
997 continue;
998 free_ret = sys_pkey_free(alloced_pkeys[i]);
999 pkey_assert(!free_ret);
1000 }
1001
1002 /* attach key-0 in various modes */
1003 err = sys_mprotect_pkey(ptr, size, PROT_READ, 0);
1004 pkey_assert(!err);
1005 err = sys_mprotect_pkey(ptr, size, PROT_WRITE, 0);
1006 pkey_assert(!err);
1007 err = sys_mprotect_pkey(ptr, size, PROT_EXEC, 0);
1008 pkey_assert(!err);
1009 err = sys_mprotect_pkey(ptr, size, PROT_READ|PROT_WRITE, 0);
1010 pkey_assert(!err);
1011 err = sys_mprotect_pkey(ptr, size, PROT_READ|PROT_WRITE|PROT_EXEC, 0);
1012 pkey_assert(!err);
1013 }
1014
1015 void test_read_of_write_disabled_region(int *ptr, u16 pkey)
1016 {
1017 int ptr_contents;
1018
1019 dprintf1("disabling write access to PKEY[1], doing read\n");
1020 pkey_write_deny(pkey);
1021 ptr_contents = read_ptr(ptr);
1022 dprintf1("*ptr: %d\n", ptr_contents);
1023 dprintf1("\n");
1024 }
1025 void test_read_of_access_disabled_region(int *ptr, u16 pkey)
1026 {
1027 int ptr_contents;
1028
1029 dprintf1("disabling access to PKEY[%02d], doing read @ %p\n", pkey, ptr);
1030 read_pkey_reg();
1031 pkey_access_deny(pkey);
1032 ptr_contents = read_ptr(ptr);
1033 dprintf1("*ptr: %d\n", ptr_contents);
1034 expected_pkey_fault(pkey);
1035 }
1036
1037 void test_read_of_access_disabled_region_with_page_already_mapped(int *ptr,
1038 u16 pkey)
1039 {
1040 int ptr_contents;
1041
1042 dprintf1("disabling access to PKEY[%02d], doing read @ %p\n",
1043 pkey, ptr);
1044 ptr_contents = read_ptr(ptr);
1045 dprintf1("reading ptr before disabling the read : %d\n",
1046 ptr_contents);
1047 read_pkey_reg();
1048 pkey_access_deny(pkey);
1049 ptr_contents = read_ptr(ptr);
1050 dprintf1("*ptr: %d\n", ptr_contents);
1051 expected_pkey_fault(pkey);
1052 }
1053
1054 void test_write_of_write_disabled_region_with_page_already_mapped(int *ptr,
1055 u16 pkey)
1056 {
1057 *ptr = __LINE__;
1058 dprintf1("disabling write access; after accessing the page, "
1059 "to PKEY[%02d], doing write\n", pkey);
1060 pkey_write_deny(pkey);
1061 *ptr = __LINE__;
1062 expected_pkey_fault(pkey);
1063 }
1064
1065 void test_write_of_write_disabled_region(int *ptr, u16 pkey)
1066 {
1067 dprintf1("disabling write access to PKEY[%02d], doing write\n", pkey);
1068 pkey_write_deny(pkey);
1069 *ptr = __LINE__;
1070 expected_pkey_fault(pkey);
1071 }
1072 void test_write_of_access_disabled_region(int *ptr, u16 pkey)
1073 {
1074 dprintf1("disabling access to PKEY[%02d], doing write\n", pkey);
1075 pkey_access_deny(pkey);
1076 *ptr = __LINE__;
1077 expected_pkey_fault(pkey);
1078 }
1079
1080 void test_write_of_access_disabled_region_with_page_already_mapped(int *ptr,
1081 u16 pkey)
1082 {
1083 *ptr = __LINE__;
1084 dprintf1("disabling access; after accessing the page, "
1085 " to PKEY[%02d], doing write\n", pkey);
1086 pkey_access_deny(pkey);
1087 *ptr = __LINE__;
1088 expected_pkey_fault(pkey);
1089 }
1090
1091 void test_kernel_write_of_access_disabled_region(int *ptr, u16 pkey)
1092 {
1093 int ret;
1094 int test_fd = get_test_read_fd();
1095
1096 dprintf1("disabling access to PKEY[%02d], "
1097 "having kernel read() to buffer\n", pkey);
1098 pkey_access_deny(pkey);
1099 ret = read(test_fd, ptr, 1);
1100 dprintf1("read ret: %d\n", ret);
1101 pkey_assert(ret);
1102 }
1103 void test_kernel_write_of_write_disabled_region(int *ptr, u16 pkey)
1104 {
1105 int ret;
1106 int test_fd = get_test_read_fd();
1107
1108 pkey_write_deny(pkey);
1109 ret = read(test_fd, ptr, 100);
1110 dprintf1("read ret: %d\n", ret);
1111 if (ret < 0 && (DEBUG_LEVEL > 0))
1112 perror("verbose read result (OK for this to be bad)");
1113 pkey_assert(ret);
1114 }
1115
1116 void test_kernel_gup_of_access_disabled_region(int *ptr, u16 pkey)
1117 {
1118 int pipe_ret, vmsplice_ret;
1119 struct iovec iov;
1120 int pipe_fds[2];
1121
1122 pipe_ret = pipe(pipe_fds);
1123
1124 pkey_assert(pipe_ret == 0);
1125 dprintf1("disabling access to PKEY[%02d], "
1126 "having kernel vmsplice from buffer\n", pkey);
1127 pkey_access_deny(pkey);
1128 iov.iov_base = ptr;
1129 iov.iov_len = PAGE_SIZE;
1130 vmsplice_ret = vmsplice(pipe_fds[1], &iov, 1, SPLICE_F_GIFT);
1131 dprintf1("vmsplice() ret: %d\n", vmsplice_ret);
1132 pkey_assert(vmsplice_ret == -1);
1133
1134 close(pipe_fds[0]);
1135 close(pipe_fds[1]);
1136 }
1137
1138 void test_kernel_gup_write_to_write_disabled_region(int *ptr, u16 pkey)
1139 {
1140 int ignored = 0xdada;
1141 int futex_ret;
1142 int some_int = __LINE__;
1143
1144 dprintf1("disabling write to PKEY[%02d], "
1145 "doing futex gunk in buffer\n", pkey);
1146 *ptr = some_int;
1147 pkey_write_deny(pkey);
1148 futex_ret = syscall(SYS_futex, ptr, FUTEX_WAIT, some_int-1, NULL,
1149 &ignored, ignored);
1150 if (DEBUG_LEVEL > 0)
1151 perror("futex");
1152 dprintf1("futex() ret: %d\n", futex_ret);
1153 }
1154
1155 /* Assumes that all pkeys other than 'pkey' are unallocated */
1156 void test_pkey_syscalls_on_non_allocated_pkey(int *ptr, u16 pkey)
1157 {
1158 int err;
1159 int i;
1160
1161 /* Note: 0 is the default pkey, so don't mess with it */
1162 for (i = 1; i < NR_PKEYS; i++) {
1163 if (pkey == i)
1164 continue;
1165
1166 dprintf1("trying get/set/free to non-allocated pkey: %2d\n", i);
1167 err = sys_pkey_free(i);
1168 pkey_assert(err);
1169
1170 err = sys_pkey_free(i);
1171 pkey_assert(err);
1172
1173 err = sys_mprotect_pkey(ptr, PAGE_SIZE, PROT_READ, i);
1174 pkey_assert(err);
1175 }
1176 }
1177
1178 /* Assumes that all pkeys other than 'pkey' are unallocated */
1179 void test_pkey_syscalls_bad_args(int *ptr, u16 pkey)
1180 {
1181 int err;
1182 int bad_pkey = NR_PKEYS+99;
1183
1184 /* pass a known-invalid pkey in: */
1185 err = sys_mprotect_pkey(ptr, PAGE_SIZE, PROT_READ, bad_pkey);
1186 pkey_assert(err);
1187 }
1188
1189 void become_child(void)
1190 {
1191 pid_t forkret;
1192
1193 forkret = fork();
1194 pkey_assert(forkret >= 0);
1195 dprintf3("[%d] fork() ret: %d\n", getpid(), forkret);
1196
1197 if (!forkret) {
1198 /* in the child */
1199 return;
1200 }
1201 exit(0);
1202 }
1203
1204 /* Assumes that all pkeys other than 'pkey' are unallocated */
1205 void test_pkey_alloc_exhaust(int *ptr, u16 pkey)
1206 {
1207 int err;
1208 int allocated_pkeys[NR_PKEYS] = {0};
1209 int nr_allocated_pkeys = 0;
1210 int i;
1211
1212 for (i = 0; i < NR_PKEYS*3; i++) {
1213 int new_pkey;
1214 dprintf1("%s() alloc loop: %d\n", __func__, i);
1215 new_pkey = alloc_pkey();
1216 dprintf4("%s()::%d, err: %d pkey_reg: 0x%016llx"
1217 " shadow: 0x%016llx\n",
1218 __func__, __LINE__, err, __read_pkey_reg(),
1219 shadow_pkey_reg);
1220 read_pkey_reg(); /* for shadow checking */
1221 dprintf2("%s() errno: %d ENOSPC: %d\n", __func__, errno, ENOSPC);
1222 if ((new_pkey == -1) && (errno == ENOSPC)) {
1223 dprintf2("%s() failed to allocate pkey after %d tries\n",
1224 __func__, nr_allocated_pkeys);
1225 } else {
1226 /*
1227 * Ensure the number of successes never
1228 * exceeds the number of keys supported
1229 * in the hardware.
1230 */
1231 pkey_assert(nr_allocated_pkeys < NR_PKEYS);
1232 allocated_pkeys[nr_allocated_pkeys++] = new_pkey;
1233 }
1234
1235 /*
1236 * Make sure that allocation state is properly
1237 * preserved across fork().
1238 */
1239 if (i == NR_PKEYS*2)
1240 become_child();
1241 }
1242
1243 dprintf3("%s()::%d\n", __func__, __LINE__);
1244
1245 /*
1246 * On x86:
1247 * There are 16 pkeys supported in hardware. Three are
1248 * allocated by the time we get here:
1249 * 1. The default key (0)
1250 * 2. One possibly consumed by an execute-only mapping.
1251 * 3. One allocated by the test code and passed in via
1252 * 'pkey' to this function.
1253 * Ensure that we can allocate at least another 13 (16-3).
1254 *
1255 * On powerpc:
1256 * There are either 5, 28, 29 or 32 pkeys supported in
1257 * hardware depending on the page size (4K or 64K) and
1258 * platform (powernv or powervm). Four are allocated by
1259 * the time we get here. These include pkey-0, pkey-1,
1260 * exec-only pkey and the one allocated by the test code.
1261 * Ensure that we can allocate the remaining.
1262 */
1263 pkey_assert(i >= (NR_PKEYS - get_arch_reserved_keys() - 1));
1264
1265 for (i = 0; i < nr_allocated_pkeys; i++) {
1266 err = sys_pkey_free(allocated_pkeys[i]);
1267 pkey_assert(!err);
1268 read_pkey_reg(); /* for shadow checking */
1269 }
1270 }
1271
1272 void arch_force_pkey_reg_init(void)
1273 {
1274 #if defined(__i386__) || defined(__x86_64__) /* arch */
1275 u64 *buf;
1276
1277 /*
1278 * All keys should be allocated and set to allow reads and
1279 * writes, so the register should be all 0. If not, just
1280 * skip the test.
1281 */
1282 if (read_pkey_reg())
1283 return;
1284
1285 /*
1286 * Just allocate an absurd about of memory rather than
1287 * doing the XSAVE size enumeration dance.
1288 */
1289 buf = mmap(NULL, 1*MB, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
1290
1291 /* These __builtins require compiling with -mxsave */
1292
1293 /* XSAVE to build a valid buffer: */
1294 __builtin_ia32_xsave(buf, XSTATE_PKEY);
1295 /* Clear XSTATE_BV[PKRU]: */
1296 buf[XSTATE_BV_OFFSET/sizeof(u64)] &= ~XSTATE_PKEY;
1297 /* XRSTOR will likely get PKRU back to the init state: */
1298 __builtin_ia32_xrstor(buf, XSTATE_PKEY);
1299
1300 munmap(buf, 1*MB);
1301 #endif
1302 }
1303
1304
1305 /*
1306 * This is mostly useless on ppc for now. But it will not
1307 * hurt anything and should give some better coverage as
1308 * a long-running test that continually checks the pkey
1309 * register.
1310 */
1311 void test_pkey_init_state(int *ptr, u16 pkey)
1312 {
1313 int err;
1314 int allocated_pkeys[NR_PKEYS] = {0};
1315 int nr_allocated_pkeys = 0;
1316 int i;
1317
1318 for (i = 0; i < NR_PKEYS; i++) {
1319 int new_pkey = alloc_pkey();
1320
1321 if (new_pkey < 0)
1322 continue;
1323 allocated_pkeys[nr_allocated_pkeys++] = new_pkey;
1324 }
1325
1326 dprintf3("%s()::%d\n", __func__, __LINE__);
1327
1328 arch_force_pkey_reg_init();
1329
1330 /*
1331 * Loop for a bit, hoping to get exercise the kernel
1332 * context switch code.
1333 */
1334 for (i = 0; i < 1000000; i++)
1335 read_pkey_reg();
1336
1337 for (i = 0; i < nr_allocated_pkeys; i++) {
1338 err = sys_pkey_free(allocated_pkeys[i]);
1339 pkey_assert(!err);
1340 read_pkey_reg(); /* for shadow checking */
1341 }
1342 }
1343
1344 /*
1345 * pkey 0 is special. It is allocated by default, so you do not
1346 * have to call pkey_alloc() to use it first. Make sure that it
1347 * is usable.
1348 */
1349 void test_mprotect_with_pkey_0(int *ptr, u16 pkey)
1350 {
1351 long size;
1352 int prot;
1353
1354 assert(pkey_last_malloc_record);
1355 size = pkey_last_malloc_record->size;
1356 /*
1357 * This is a bit of a hack. But mprotect() requires
1358 * huge-page-aligned sizes when operating on hugetlbfs.
1359 * So, make sure that we use something that's a multiple
1360 * of a huge page when we can.
1361 */
1362 if (size >= HPAGE_SIZE)
1363 size = HPAGE_SIZE;
1364 prot = pkey_last_malloc_record->prot;
1365
1366 /* Use pkey 0 */
1367 mprotect_pkey(ptr, size, prot, 0);
1368
1369 /* Make sure that we can set it back to the original pkey. */
1370 mprotect_pkey(ptr, size, prot, pkey);
1371 }
1372
1373 void test_ptrace_of_child(int *ptr, u16 pkey)
1374 {
1375 __attribute__((__unused__)) int peek_result;
1376 pid_t child_pid;
1377 void *ignored = 0;
1378 long ret;
1379 int status;
1380 /*
1381 * This is the "control" for our little expermient. Make sure
1382 * we can always access it when ptracing.
1383 */
1384 int *plain_ptr_unaligned = malloc(HPAGE_SIZE);
1385 int *plain_ptr = ALIGN_PTR_UP(plain_ptr_unaligned, PAGE_SIZE);
1386
1387 /*
1388 * Fork a child which is an exact copy of this process, of course.
1389 * That means we can do all of our tests via ptrace() and then plain
1390 * memory access and ensure they work differently.
1391 */
1392 child_pid = fork_lazy_child();
1393 dprintf1("[%d] child pid: %d\n", getpid(), child_pid);
1394
1395 ret = ptrace(PTRACE_ATTACH, child_pid, ignored, ignored);
1396 if (ret)
1397 perror("attach");
1398 dprintf1("[%d] attach ret: %ld %d\n", getpid(), ret, __LINE__);
1399 pkey_assert(ret != -1);
1400 ret = waitpid(child_pid, &status, WUNTRACED);
1401 if ((ret != child_pid) || !(WIFSTOPPED(status))) {
1402 fprintf(stderr, "weird waitpid result %ld stat %x\n",
1403 ret, status);
1404 pkey_assert(0);
1405 }
1406 dprintf2("waitpid ret: %ld\n", ret);
1407 dprintf2("waitpid status: %d\n", status);
1408
1409 pkey_access_deny(pkey);
1410 pkey_write_deny(pkey);
1411
1412 /* Write access, untested for now:
1413 ret = ptrace(PTRACE_POKEDATA, child_pid, peek_at, data);
1414 pkey_assert(ret != -1);
1415 dprintf1("poke at %p: %ld\n", peek_at, ret);
1416 */
1417
1418 /*
1419 * Try to access the pkey-protected "ptr" via ptrace:
1420 */
1421 ret = ptrace(PTRACE_PEEKDATA, child_pid, ptr, ignored);
1422 /* expect it to work, without an error: */
1423 pkey_assert(ret != -1);
1424 /* Now access from the current task, and expect an exception: */
1425 peek_result = read_ptr(ptr);
1426 expected_pkey_fault(pkey);
1427
1428 /*
1429 * Try to access the NON-pkey-protected "plain_ptr" via ptrace:
1430 */
1431 ret = ptrace(PTRACE_PEEKDATA, child_pid, plain_ptr, ignored);
1432 /* expect it to work, without an error: */
1433 pkey_assert(ret != -1);
1434 /* Now access from the current task, and expect NO exception: */
1435 peek_result = read_ptr(plain_ptr);
1436 do_not_expect_pkey_fault("read plain pointer after ptrace");
1437
1438 ret = ptrace(PTRACE_DETACH, child_pid, ignored, 0);
1439 pkey_assert(ret != -1);
1440
1441 ret = kill(child_pid, SIGKILL);
1442 pkey_assert(ret != -1);
1443
1444 wait(&status);
1445
1446 free(plain_ptr_unaligned);
1447 }
1448
1449 void *get_pointer_to_instructions(void)
1450 {
1451 void *p1;
1452
1453 p1 = ALIGN_PTR_UP(&lots_o_noops_around_write, PAGE_SIZE);
1454 dprintf3("&lots_o_noops: %p\n", &lots_o_noops_around_write);
1455 /* lots_o_noops_around_write should be page-aligned already */
1456 assert(p1 == &lots_o_noops_around_write);
1457
1458 /* Point 'p1' at the *second* page of the function: */
1459 p1 += PAGE_SIZE;
1460
1461 /*
1462 * Try to ensure we fault this in on next touch to ensure
1463 * we get an instruction fault as opposed to a data one
1464 */
1465 madvise(p1, PAGE_SIZE, MADV_DONTNEED);
1466
1467 return p1;
1468 }
1469
1470 void test_executing_on_unreadable_memory(int *ptr, u16 pkey)
1471 {
1472 void *p1;
1473 int scratch;
1474 int ptr_contents;
1475 int ret;
1476
1477 p1 = get_pointer_to_instructions();
1478 lots_o_noops_around_write(&scratch);
1479 ptr_contents = read_ptr(p1);
1480 dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents);
1481
1482 ret = mprotect_pkey(p1, PAGE_SIZE, PROT_EXEC, (u64)pkey);
1483 pkey_assert(!ret);
1484 pkey_access_deny(pkey);
1485
1486 dprintf2("pkey_reg: %016llx\n", read_pkey_reg());
1487
1488 /*
1489 * Make sure this is an *instruction* fault
1490 */
1491 madvise(p1, PAGE_SIZE, MADV_DONTNEED);
1492 lots_o_noops_around_write(&scratch);
1493 do_not_expect_pkey_fault("executing on PROT_EXEC memory");
1494 expect_fault_on_read_execonly_key(p1, pkey);
1495 }
1496
1497 void test_implicit_mprotect_exec_only_memory(int *ptr, u16 pkey)
1498 {
1499 void *p1;
1500 int scratch;
1501 int ptr_contents;
1502 int ret;
1503
1504 dprintf1("%s() start\n", __func__);
1505
1506 p1 = get_pointer_to_instructions();
1507 lots_o_noops_around_write(&scratch);
1508 ptr_contents = read_ptr(p1);
1509 dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents);
1510
1511 /* Use a *normal* mprotect(), not mprotect_pkey(): */
1512 ret = mprotect(p1, PAGE_SIZE, PROT_EXEC);
1513 pkey_assert(!ret);
1514
1515 /*
1516 * Reset the shadow, assuming that the above mprotect()
1517 * correctly changed PKRU, but to an unknown value since
1518 * the actual allocated pkey is unknown.
1519 */
1520 shadow_pkey_reg = __read_pkey_reg();
1521
1522 dprintf2("pkey_reg: %016llx\n", read_pkey_reg());
1523
1524 /* Make sure this is an *instruction* fault */
1525 madvise(p1, PAGE_SIZE, MADV_DONTNEED);
1526 lots_o_noops_around_write(&scratch);
1527 do_not_expect_pkey_fault("executing on PROT_EXEC memory");
1528 expect_fault_on_read_execonly_key(p1, UNKNOWN_PKEY);
1529
1530 /*
1531 * Put the memory back to non-PROT_EXEC. Should clear the
1532 * exec-only pkey off the VMA and allow it to be readable
1533 * again. Go to PROT_NONE first to check for a kernel bug
1534 * that did not clear the pkey when doing PROT_NONE.
1535 */
1536 ret = mprotect(p1, PAGE_SIZE, PROT_NONE);
1537 pkey_assert(!ret);
1538
1539 ret = mprotect(p1, PAGE_SIZE, PROT_READ|PROT_EXEC);
1540 pkey_assert(!ret);
1541 ptr_contents = read_ptr(p1);
1542 do_not_expect_pkey_fault("plain read on recently PROT_EXEC area");
1543 }
1544
1545 #if defined(__i386__) || defined(__x86_64__)
1546 void test_ptrace_modifies_pkru(int *ptr, u16 pkey)
1547 {
1548 u32 new_pkru;
1549 pid_t child;
1550 int status, ret;
1551 int pkey_offset = pkey_reg_xstate_offset();
1552 size_t xsave_size = cpu_max_xsave_size();
1553 void *xsave;
1554 u32 *pkey_register;
1555 u64 *xstate_bv;
1556 struct iovec iov;
1557
1558 new_pkru = ~read_pkey_reg();
1559 /* Don't make PROT_EXEC mappings inaccessible */
1560 new_pkru &= ~3;
1561
1562 child = fork();
1563 pkey_assert(child >= 0);
1564 dprintf3("[%d] fork() ret: %d\n", getpid(), child);
1565 if (!child) {
1566 ptrace(PTRACE_TRACEME, 0, 0, 0);
1567 /* Stop and allow the tracer to modify PKRU directly */
1568 raise(SIGSTOP);
1569
1570 /*
1571 * need __read_pkey_reg() version so we do not do shadow_pkey_reg
1572 * checking
1573 */
1574 if (__read_pkey_reg() != new_pkru)
1575 exit(1);
1576
1577 /* Stop and allow the tracer to clear XSTATE_BV for PKRU */
1578 raise(SIGSTOP);
1579
1580 if (__read_pkey_reg() != 0)
1581 exit(1);
1582
1583 /* Stop and allow the tracer to examine PKRU */
1584 raise(SIGSTOP);
1585
1586 exit(0);
1587 }
1588
1589 pkey_assert(child == waitpid(child, &status, 0));
1590 dprintf3("[%d] waitpid(%d) status: %x\n", getpid(), child, status);
1591 pkey_assert(WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP);
1592
1593 xsave = (void *)malloc(xsave_size);
1594 pkey_assert(xsave > 0);
1595
1596 /* Modify the PKRU register directly */
1597 iov.iov_base = xsave;
1598 iov.iov_len = xsave_size;
1599 ret = ptrace(PTRACE_GETREGSET, child, (void *)NT_X86_XSTATE, &iov);
1600 pkey_assert(ret == 0);
1601
1602 pkey_register = (u32 *)(xsave + pkey_offset);
1603 pkey_assert(*pkey_register == read_pkey_reg());
1604
1605 *pkey_register = new_pkru;
1606
1607 ret = ptrace(PTRACE_SETREGSET, child, (void *)NT_X86_XSTATE, &iov);
1608 pkey_assert(ret == 0);
1609
1610 /* Test that the modification is visible in ptrace before any execution */
1611 memset(xsave, 0xCC, xsave_size);
1612 ret = ptrace(PTRACE_GETREGSET, child, (void *)NT_X86_XSTATE, &iov);
1613 pkey_assert(ret == 0);
1614 pkey_assert(*pkey_register == new_pkru);
1615
1616 /* Execute the tracee */
1617 ret = ptrace(PTRACE_CONT, child, 0, 0);
1618 pkey_assert(ret == 0);
1619
1620 /* Test that the tracee saw the PKRU value change */
1621 pkey_assert(child == waitpid(child, &status, 0));
1622 dprintf3("[%d] waitpid(%d) status: %x\n", getpid(), child, status);
1623 pkey_assert(WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP);
1624
1625 /* Test that the modification is visible in ptrace after execution */
1626 memset(xsave, 0xCC, xsave_size);
1627 ret = ptrace(PTRACE_GETREGSET, child, (void *)NT_X86_XSTATE, &iov);
1628 pkey_assert(ret == 0);
1629 pkey_assert(*pkey_register == new_pkru);
1630
1631 /* Clear the PKRU bit from XSTATE_BV */
1632 xstate_bv = (u64 *)(xsave + 512);
1633 *xstate_bv &= ~(1 << 9);
1634
1635 ret = ptrace(PTRACE_SETREGSET, child, (void *)NT_X86_XSTATE, &iov);
1636 pkey_assert(ret == 0);
1637
1638 /* Test that the modification is visible in ptrace before any execution */
1639 memset(xsave, 0xCC, xsave_size);
1640 ret = ptrace(PTRACE_GETREGSET, child, (void *)NT_X86_XSTATE, &iov);
1641 pkey_assert(ret == 0);
1642 pkey_assert(*pkey_register == 0);
1643
1644 ret = ptrace(PTRACE_CONT, child, 0, 0);
1645 pkey_assert(ret == 0);
1646
1647 /* Test that the tracee saw the PKRU value go to 0 */
1648 pkey_assert(child == waitpid(child, &status, 0));
1649 dprintf3("[%d] waitpid(%d) status: %x\n", getpid(), child, status);
1650 pkey_assert(WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP);
1651
1652 /* Test that the modification is visible in ptrace after execution */
1653 memset(xsave, 0xCC, xsave_size);
1654 ret = ptrace(PTRACE_GETREGSET, child, (void *)NT_X86_XSTATE, &iov);
1655 pkey_assert(ret == 0);
1656 pkey_assert(*pkey_register == 0);
1657
1658 ret = ptrace(PTRACE_CONT, child, 0, 0);
1659 pkey_assert(ret == 0);
1660 pkey_assert(child == waitpid(child, &status, 0));
1661 dprintf3("[%d] waitpid(%d) status: %x\n", getpid(), child, status);
1662 pkey_assert(WIFEXITED(status));
1663 pkey_assert(WEXITSTATUS(status) == 0);
1664 free(xsave);
1665 }
1666 #endif
1667
1668 void test_mprotect_pkey_on_unsupported_cpu(int *ptr, u16 pkey)
1669 {
1670 int size = PAGE_SIZE;
1671 int sret;
1672
1673 if (cpu_has_pkeys()) {
1674 dprintf1("SKIP: %s: no CPU support\n", __func__);
1675 return;
1676 }
1677
1678 sret = syscall(__NR_pkey_mprotect, ptr, size, PROT_READ, pkey);
1679 pkey_assert(sret < 0);
1680 }
1681
1682 void (*pkey_tests[])(int *ptr, u16 pkey) = {
1683 test_read_of_write_disabled_region,
1684 test_read_of_access_disabled_region,
1685 test_read_of_access_disabled_region_with_page_already_mapped,
1686 test_write_of_write_disabled_region,
1687 test_write_of_write_disabled_region_with_page_already_mapped,
1688 test_write_of_access_disabled_region,
1689 test_write_of_access_disabled_region_with_page_already_mapped,
1690 test_kernel_write_of_access_disabled_region,
1691 test_kernel_write_of_write_disabled_region,
1692 test_kernel_gup_of_access_disabled_region,
1693 test_kernel_gup_write_to_write_disabled_region,
1694 test_executing_on_unreadable_memory,
1695 test_implicit_mprotect_exec_only_memory,
1696 test_mprotect_with_pkey_0,
1697 test_ptrace_of_child,
1698 test_pkey_init_state,
1699 test_pkey_syscalls_on_non_allocated_pkey,
1700 test_pkey_syscalls_bad_args,
1701 test_pkey_alloc_exhaust,
1702 test_pkey_alloc_free_attach_pkey0,
1703 #if defined(__i386__) || defined(__x86_64__)
1704 test_ptrace_modifies_pkru,
1705 #endif
1706 };
1707
1708 void run_tests_once(void)
1709 {
1710 int *ptr;
1711 int prot = PROT_READ|PROT_WRITE;
1712
1713 for (test_nr = 0; test_nr < ARRAY_SIZE(pkey_tests); test_nr++) {
1714 int pkey;
1715 int orig_pkey_faults = pkey_faults;
1716
1717 dprintf1("======================\n");
1718 dprintf1("test %d preparing...\n", test_nr);
1719
1720 tracing_on();
1721 pkey = alloc_random_pkey();
1722 dprintf1("test %d starting with pkey: %d\n", test_nr, pkey);
1723 ptr = malloc_pkey(PAGE_SIZE, prot, pkey);
1724 dprintf1("test %d starting...\n", test_nr);
1725 pkey_tests[test_nr](ptr, pkey);
1726 dprintf1("freeing test memory: %p\n", ptr);
1727 free_pkey_malloc(ptr);
1728 sys_pkey_free(pkey);
1729
1730 dprintf1("pkey_faults: %d\n", pkey_faults);
1731 dprintf1("orig_pkey_faults: %d\n", orig_pkey_faults);
1732
1733 tracing_off();
1734 close_test_fds();
1735
1736 printf("test %2d PASSED (iteration %d)\n", test_nr, iteration_nr);
1737 dprintf1("======================\n\n");
1738 }
1739 iteration_nr++;
1740 }
1741
1742 void pkey_setup_shadow(void)
1743 {
1744 shadow_pkey_reg = __read_pkey_reg();
1745 }
1746
1747 int main(void)
1748 {
1749 int nr_iterations = 22;
1750 int pkeys_supported = is_pkeys_supported();
1751
1752 srand((unsigned int)time(NULL));
1753
1754 setup_handlers();
1755
1756 printf("has pkeys: %d\n", pkeys_supported);
1757
1758 if (!pkeys_supported) {
1759 int size = PAGE_SIZE;
1760 int *ptr;
1761
1762 printf("running PKEY tests for unsupported CPU/OS\n");
1763
1764 ptr = mmap(NULL, size, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
1765 assert(ptr != (void *)-1);
1766 test_mprotect_pkey_on_unsupported_cpu(ptr, 1);
1767 exit(0);
1768 }
1769
1770 pkey_setup_shadow();
1771 printf("startup pkey_reg: %016llx\n", read_pkey_reg());
1772 setup_hugetlbfs();
1773
1774 while (nr_iterations-- > 0)
1775 run_tests_once();
1776
1777 printf("done (all tests OK)\n");
1778 return 0;
1779 }
1780
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.