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v3.5.6
 
  1/*
  2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  3 * Licensed under the GPL
  4 */
  5
  6#include <stdio.h>
  7#include <stdlib.h>
  8#include <stdarg.h>
  9#include <unistd.h>
 10#include <errno.h>
 11#include <fcntl.h>
 12#include <sched.h>
 13#include <signal.h>
 14#include <string.h>
 15#include <sys/mman.h>
 16#include <sys/stat.h>
 17#include <sys/wait.h>
 
 
 
 18#include <asm/unistd.h>
 19#include "init.h"
 20#include "os.h"
 21#include "mem_user.h"
 22#include "ptrace_user.h"
 23#include "registers.h"
 24#include "skas.h"
 25#include "skas_ptrace.h"
 
 26
 27static void ptrace_child(void)
 28{
 29	int ret;
 30	/* Calling os_getpid because some libcs cached getpid incorrectly */
 31	int pid = os_getpid(), ppid = getppid();
 32	int sc_result;
 33
 34	if (change_sig(SIGWINCH, 0) < 0 ||
 35	    ptrace(PTRACE_TRACEME, 0, 0, 0) < 0) {
 36		perror("ptrace");
 37		kill(pid, SIGKILL);
 38	}
 39	kill(pid, SIGSTOP);
 40
 41	/*
 42	 * This syscall will be intercepted by the parent. Don't call more than
 43	 * once, please.
 44	 */
 45	sc_result = os_getpid();
 46
 47	if (sc_result == pid)
 48		/* Nothing modified by the parent, we are running normally. */
 49		ret = 1;
 50	else if (sc_result == ppid)
 51		/*
 52		 * Expected in check_ptrace and check_sysemu when they succeed
 53		 * in modifying the stack frame
 54		 */
 55		ret = 0;
 56	else
 57		/* Serious trouble! This could be caused by a bug in host 2.6
 58		 * SKAS3/2.6 patch before release -V6, together with a bug in
 59		 * the UML code itself.
 60		 */
 61		ret = 2;
 62
 63	exit(ret);
 64}
 65
 66static void fatal_perror(const char *str)
 67{
 68	perror(str);
 69	exit(1);
 70}
 71
 72static void fatal(char *fmt, ...)
 73{
 74	va_list list;
 75
 76	va_start(list, fmt);
 77	vfprintf(stderr, fmt, list);
 78	va_end(list);
 79
 80	exit(1);
 81}
 82
 83static void non_fatal(char *fmt, ...)
 84{
 85	va_list list;
 86
 87	va_start(list, fmt);
 88	vfprintf(stderr, fmt, list);
 89	va_end(list);
 90}
 91
 92static int start_ptraced_child(void)
 93{
 94	int pid, n, status;
 95
 
 
 96	pid = fork();
 97	if (pid == 0)
 98		ptrace_child();
 99	else if (pid < 0)
100		fatal_perror("start_ptraced_child : fork failed");
101
102	CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
103	if (n < 0)
104		fatal_perror("check_ptrace : waitpid failed");
105	if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
106		fatal("check_ptrace : expected SIGSTOP, got status = %d",
107		      status);
108
109	return pid;
110}
111
112/* When testing for SYSEMU support, if it is one of the broken versions, we
113 * must just avoid using sysemu, not panic, but only if SYSEMU features are
114 * broken.
115 * So only for SYSEMU features we test mustpanic, while normal host features
116 * must work anyway!
117 */
118static int stop_ptraced_child(int pid, int exitcode, int mustexit)
119{
120	int status, n, ret = 0;
 
 
 
121
122	if (ptrace(PTRACE_CONT, pid, 0, 0) < 0) {
123		perror("stop_ptraced_child : ptrace failed");
124		return -1;
125	}
126	CATCH_EINTR(n = waitpid(pid, &status, 0));
127	if (!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) {
128		int exit_with = WEXITSTATUS(status);
129		if (exit_with == 2)
130			non_fatal("check_ptrace : child exited with status 2. "
131				  "\nDisabling SYSEMU support.\n");
132		non_fatal("check_ptrace : child exited with exitcode %d, while "
133			  "expecting %d; status 0x%x\n", exit_with,
134			  exitcode, status);
135		if (mustexit)
136			exit(1);
137		ret = -1;
138	}
139
140	return ret;
141}
142
143/* Changed only during early boot */
144int ptrace_faultinfo;
145static int disable_ptrace_faultinfo;
146
147int ptrace_ldt;
148static int disable_ptrace_ldt;
149
150int proc_mm;
151static int disable_proc_mm;
152
153int have_switch_mm;
154static int disable_switch_mm;
155
156int skas_needs_stub;
157
158static int __init skas0_cmd_param(char *str, int* add)
159{
160	disable_ptrace_faultinfo = 1;
161	disable_ptrace_ldt = 1;
162	disable_proc_mm = 1;
163	disable_switch_mm = 1;
164
165	return 0;
166}
167
168/* The two __uml_setup would conflict, without this stupid alias. */
169
170static int __init mode_skas0_cmd_param(char *str, int* add)
171	__attribute__((alias("skas0_cmd_param")));
172
173__uml_setup("skas0", skas0_cmd_param,
174"skas0\n"
175"    Disables SKAS3 and SKAS4 usage, so that SKAS0 is used\n\n");
176
177__uml_setup("mode=skas0", mode_skas0_cmd_param,
178"mode=skas0\n"
179"    Disables SKAS3 and SKAS4 usage, so that SKAS0 is used.\n\n");
180
181/* Changed only during early boot */
182static int force_sysemu_disabled = 0;
183
184static int __init nosysemu_cmd_param(char *str, int* add)
185{
186	force_sysemu_disabled = 1;
187	return 0;
188}
189
190__uml_setup("nosysemu", nosysemu_cmd_param,
191"nosysemu\n"
192"    Turns off syscall emulation patch for ptrace (SYSEMU) on.\n"
193"    SYSEMU is a performance-patch introduced by Laurent Vivier. It changes\n"
194"    behaviour of ptrace() and helps reducing host context switch rate.\n"
195"    To make it working, you need a kernel patch for your host, too.\n"
196"    See http://perso.wanadoo.fr/laurent.vivier/UML/ for further \n"
197"    information.\n\n");
198
199static void __init check_sysemu(void)
200{
201	unsigned long regs[MAX_REG_NR];
202	int pid, n, status, count=0;
203
204	non_fatal("Checking syscall emulation patch for ptrace...");
205	sysemu_supported = 0;
206	pid = start_ptraced_child();
207
208	if (ptrace(PTRACE_SYSEMU, pid, 0, 0) < 0)
209		goto fail;
210
211	CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
212	if (n < 0)
213		fatal_perror("check_sysemu : wait failed");
214	if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
215		fatal("check_sysemu : expected SIGTRAP, got status = %d\n",
216		      status);
217
218	if (ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
219		fatal_perror("check_sysemu : PTRACE_GETREGS failed");
220	if (PT_SYSCALL_NR(regs) != __NR_getpid) {
221		non_fatal("check_sysemu got system call number %d, "
222			  "expected %d...", PT_SYSCALL_NR(regs), __NR_getpid);
223		goto fail;
224	}
225
226	n = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_RET_OFFSET, os_getpid());
227	if (n < 0) {
228		non_fatal("check_sysemu : failed to modify system call "
229			  "return");
230		goto fail;
231	}
232
233	if (stop_ptraced_child(pid, 0, 0) < 0)
234		goto fail_stopped;
235
236	sysemu_supported = 1;
237	non_fatal("OK\n");
238	set_using_sysemu(!force_sysemu_disabled);
239
240	non_fatal("Checking advanced syscall emulation patch for ptrace...");
241	pid = start_ptraced_child();
242
243	if ((ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
244		   (void *) PTRACE_O_TRACESYSGOOD) < 0))
245		fatal_perror("check_sysemu: PTRACE_OLDSETOPTIONS failed");
246
247	while (1) {
248		count++;
249		if (ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0)
250			goto fail;
251		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
252		if (n < 0)
253			fatal_perror("check_sysemu: wait failed");
254
255		if (WIFSTOPPED(status) &&
256		    (WSTOPSIG(status) == (SIGTRAP|0x80))) {
257			if (!count) {
258				non_fatal("check_sysemu: SYSEMU_SINGLESTEP "
259					  "doesn't singlestep");
260				goto fail;
261			}
262			n = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_RET_OFFSET,
263				   os_getpid());
264			if (n < 0)
265				fatal_perror("check_sysemu : failed to modify "
266					     "system call return");
267			break;
268		}
269		else if (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGTRAP))
270			count++;
271		else {
272			non_fatal("check_sysemu: expected SIGTRAP or "
273				  "(SIGTRAP | 0x80), got status = %d\n",
274				  status);
275			goto fail;
276		}
277	}
278	if (stop_ptraced_child(pid, 0, 0) < 0)
279		goto fail_stopped;
280
281	sysemu_supported = 2;
282	non_fatal("OK\n");
283
284	if (!force_sysemu_disabled)
285		set_using_sysemu(sysemu_supported);
286	return;
287
288fail:
289	stop_ptraced_child(pid, 1, 0);
290fail_stopped:
291	non_fatal("missing\n");
292}
293
294static void __init check_ptrace(void)
295{
296	int pid, syscall, n, status;
297
298	non_fatal("Checking that ptrace can change system call numbers...");
299	pid = start_ptraced_child();
300
301	if ((ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
302		   (void *) PTRACE_O_TRACESYSGOOD) < 0))
303		fatal_perror("check_ptrace: PTRACE_OLDSETOPTIONS failed");
304
305	while (1) {
306		if (ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0)
307			fatal_perror("check_ptrace : ptrace failed");
308
309		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
310		if (n < 0)
311			fatal_perror("check_ptrace : wait failed");
312
313		if (!WIFSTOPPED(status) ||
314		   (WSTOPSIG(status) != (SIGTRAP | 0x80)))
315			fatal("check_ptrace : expected (SIGTRAP|0x80), "
316			       "got status = %d", status);
317
318		syscall = ptrace(PTRACE_PEEKUSER, pid, PT_SYSCALL_NR_OFFSET,
319				 0);
320		if (syscall == __NR_getpid) {
321			n = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_NR_OFFSET,
322				   __NR_getppid);
323			if (n < 0)
324				fatal_perror("check_ptrace : failed to modify "
325					     "system call");
326			break;
327		}
328	}
329	stop_ptraced_child(pid, 0, 1);
330	non_fatal("OK\n");
331	check_sysemu();
332}
333
334extern void check_tmpexec(void);
335
336static void __init check_coredump_limit(void)
337{
338	struct rlimit lim;
339	int err = getrlimit(RLIMIT_CORE, &lim);
340
341	if (err) {
342		perror("Getting core dump limit");
343		return;
344	}
345
346	printf("Core dump limits :\n\tsoft - ");
347	if (lim.rlim_cur == RLIM_INFINITY)
348		printf("NONE\n");
349	else printf("%lu\n", lim.rlim_cur);
 
350
351	printf("\thard - ");
352	if (lim.rlim_max == RLIM_INFINITY)
353		printf("NONE\n");
354	else printf("%lu\n", lim.rlim_max);
 
355}
356
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
357void __init os_early_checks(void)
358{
359	int pid;
360
361	/* Print out the core dump limits early */
362	check_coredump_limit();
363
364	check_ptrace();
365
366	/* Need to check this early because mmapping happens before the
367	 * kernel is running.
368	 */
369	check_tmpexec();
370
371	pid = start_ptraced_child();
372	if (init_registers(pid))
373		fatal("Failed to initialize default registers");
374	stop_ptraced_child(pid, 1, 1);
375}
376
377static int __init noprocmm_cmd_param(char *str, int* add)
378{
379	disable_proc_mm = 1;
380	return 0;
381}
382
383__uml_setup("noprocmm", noprocmm_cmd_param,
384"noprocmm\n"
385"    Turns off usage of /proc/mm, even if host supports it.\n"
386"    To support /proc/mm, the host needs to be patched using\n"
387"    the current skas3 patch.\n\n");
388
389static int __init noptracefaultinfo_cmd_param(char *str, int* add)
390{
391	disable_ptrace_faultinfo = 1;
392	return 0;
393}
394
395__uml_setup("noptracefaultinfo", noptracefaultinfo_cmd_param,
396"noptracefaultinfo\n"
397"    Turns off usage of PTRACE_FAULTINFO, even if host supports\n"
398"    it. To support PTRACE_FAULTINFO, the host needs to be patched\n"
399"    using the current skas3 patch.\n\n");
400
401static int __init noptraceldt_cmd_param(char *str, int* add)
402{
403	disable_ptrace_ldt = 1;
404	return 0;
405}
406
407__uml_setup("noptraceldt", noptraceldt_cmd_param,
408"noptraceldt\n"
409"    Turns off usage of PTRACE_LDT, even if host supports it.\n"
410"    To support PTRACE_LDT, the host needs to be patched using\n"
411"    the current skas3 patch.\n\n");
412
413static inline void check_skas3_ptrace_faultinfo(void)
414{
415	struct ptrace_faultinfo fi;
416	int pid, n;
417
418	non_fatal("  - PTRACE_FAULTINFO...");
419	pid = start_ptraced_child();
420
421	n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi);
422	if (n < 0) {
423		if (errno == EIO)
424			non_fatal("not found\n");
425		else
426			perror("not found");
427	} else if (disable_ptrace_faultinfo)
428		non_fatal("found but disabled on command line\n");
429	else {
430		ptrace_faultinfo = 1;
431		non_fatal("found\n");
432	}
433
434	stop_ptraced_child(pid, 1, 1);
435}
436
437static inline void check_skas3_ptrace_ldt(void)
438{
439#ifdef PTRACE_LDT
440	int pid, n;
441	unsigned char ldtbuf[40];
442	struct ptrace_ldt ldt_op = (struct ptrace_ldt) {
443		.func = 2, /* read default ldt */
444		.ptr = ldtbuf,
445		.bytecount = sizeof(ldtbuf)};
446
447	non_fatal("  - PTRACE_LDT...");
448	pid = start_ptraced_child();
449
450	n = ptrace(PTRACE_LDT, pid, 0, (unsigned long) &ldt_op);
451	if (n < 0) {
452		if (errno == EIO)
453			non_fatal("not found\n");
454		else
455			perror("not found");
456	} else if (disable_ptrace_ldt)
457		non_fatal("found, but use is disabled\n");
458	else {
459		ptrace_ldt = 1;
460		non_fatal("found\n");
461	}
462
463	stop_ptraced_child(pid, 1, 1);
464#endif
465}
466
467static inline void check_skas3_proc_mm(void)
468{
469	non_fatal("  - /proc/mm...");
470	if (access("/proc/mm", W_OK) < 0)
471		perror("not found");
472	else if (disable_proc_mm)
473		non_fatal("found but disabled on command line\n");
474	else {
475		proc_mm = 1;
476		non_fatal("found\n");
477	}
478}
479
480void can_do_skas(void)
481{
482	non_fatal("Checking for the skas3 patch in the host:\n");
483
484	check_skas3_proc_mm();
485	check_skas3_ptrace_faultinfo();
486	check_skas3_ptrace_ldt();
487
488	if (!proc_mm || !ptrace_faultinfo || !ptrace_ldt)
489		skas_needs_stub = 1;
490}
491
492int __init parse_iomem(char *str, int *add)
493{
494	struct iomem_region *new;
495	struct stat64 buf;
496	char *file, *driver;
497	int fd, size;
498
499	driver = str;
500	file = strchr(str,',');
501	if (file == NULL) {
502		fprintf(stderr, "parse_iomem : failed to parse iomem\n");
503		goto out;
504	}
505	*file = '\0';
506	file++;
507	fd = open(file, O_RDWR, 0);
508	if (fd < 0) {
509		perror("parse_iomem - Couldn't open io file");
510		goto out;
511	}
512
513	if (fstat64(fd, &buf) < 0) {
514		perror("parse_iomem - cannot stat_fd file");
515		goto out_close;
516	}
517
518	new = malloc(sizeof(*new));
519	if (new == NULL) {
520		perror("Couldn't allocate iomem_region struct");
521		goto out_close;
522	}
523
524	size = (buf.st_size + UM_KERN_PAGE_SIZE) & ~(UM_KERN_PAGE_SIZE - 1);
525
526	*new = ((struct iomem_region) { .next		= iomem_regions,
527					.driver		= driver,
528					.fd		= fd,
529					.size		= size,
530					.phys		= 0,
531					.virt		= 0 });
532	iomem_regions = new;
533	iomem_size += new->size + UM_KERN_PAGE_SIZE;
534
535	return 0;
536 out_close:
537	close(fd);
538 out:
539	return 1;
540}
v6.13.7
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 
  4 */
  5
  6#include <stdio.h>
  7#include <stdlib.h>
  8#include <stdarg.h>
  9#include <unistd.h>
 10#include <errno.h>
 11#include <fcntl.h>
 12#include <sched.h>
 13#include <signal.h>
 14#include <string.h>
 15#include <sys/mman.h>
 16#include <sys/stat.h>
 17#include <sys/wait.h>
 18#include <sys/time.h>
 19#include <sys/resource.h>
 20#include <asm/ldt.h>
 21#include <asm/unistd.h>
 22#include <init.h>
 23#include <os.h>
 24#include <kern_util.h>
 25#include <mem_user.h>
 26#include <ptrace_user.h>
 27#include <registers.h>
 28#include <skas.h>
 29#include "internal.h"
 30
 31static void ptrace_child(void)
 32{
 33	int ret;
 34	/* Calling os_getpid because some libcs cached getpid incorrectly */
 35	int pid = os_getpid(), ppid = getppid();
 36	int sc_result;
 37
 38	if (change_sig(SIGWINCH, 0) < 0 ||
 39	    ptrace(PTRACE_TRACEME, 0, 0, 0) < 0) {
 40		perror("ptrace");
 41		kill(pid, SIGKILL);
 42	}
 43	kill(pid, SIGSTOP);
 44
 45	/*
 46	 * This syscall will be intercepted by the parent. Don't call more than
 47	 * once, please.
 48	 */
 49	sc_result = os_getpid();
 50
 51	if (sc_result == pid)
 52		/* Nothing modified by the parent, we are running normally. */
 53		ret = 1;
 54	else if (sc_result == ppid)
 55		/*
 56		 * Expected in check_ptrace and check_sysemu when they succeed
 57		 * in modifying the stack frame
 58		 */
 59		ret = 0;
 60	else
 61		/* Serious trouble! This could be caused by a bug in host 2.6
 62		 * SKAS3/2.6 patch before release -V6, together with a bug in
 63		 * the UML code itself.
 64		 */
 65		ret = 2;
 66
 67	exit(ret);
 68}
 69
 70static void fatal_perror(const char *str)
 71{
 72	perror(str);
 73	exit(1);
 74}
 75
 76static void fatal(char *fmt, ...)
 77{
 78	va_list list;
 79
 80	va_start(list, fmt);
 81	vfprintf(stderr, fmt, list);
 82	va_end(list);
 83
 84	exit(1);
 85}
 86
 87static void non_fatal(char *fmt, ...)
 88{
 89	va_list list;
 90
 91	va_start(list, fmt);
 92	vfprintf(stderr, fmt, list);
 93	va_end(list);
 94}
 95
 96static int start_ptraced_child(void)
 97{
 98	int pid, n, status;
 99
100	fflush(stdout);
101
102	pid = fork();
103	if (pid == 0)
104		ptrace_child();
105	else if (pid < 0)
106		fatal_perror("start_ptraced_child : fork failed");
107
108	CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
109	if (n < 0)
110		fatal_perror("check_ptrace : waitpid failed");
111	if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
112		fatal("check_ptrace : expected SIGSTOP, got status = %d",
113		      status);
114
115	return pid;
116}
117
118static void stop_ptraced_child(int pid, int exitcode)
 
 
 
 
 
 
119{
120	int status, n;
121
122	if (ptrace(PTRACE_CONT, pid, 0, 0) < 0)
123		fatal_perror("stop_ptraced_child : ptrace failed");
124
 
 
 
 
125	CATCH_EINTR(n = waitpid(pid, &status, 0));
126	if (!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) {
127		int exit_with = WEXITSTATUS(status);
128		fatal("stop_ptraced_child : child exited with exitcode %d, "
129		      "while expecting %d; status 0x%x\n", exit_with,
130		      exitcode, status);
 
 
 
 
 
 
131	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
132}
133
 
 
 
 
 
 
 
 
 
134static void __init check_sysemu(void)
135{
 
136	int pid, n, status, count=0;
137
138	os_info("Checking syscall emulation for ptrace...");
 
139	pid = start_ptraced_child();
140
141	if ((ptrace(PTRACE_SETOPTIONS, pid, 0,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
142		   (void *) PTRACE_O_TRACESYSGOOD) < 0))
143		fatal_perror("check_sysemu: PTRACE_SETOPTIONS failed");
144
145	while (1) {
146		count++;
147		if (ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0)
148			goto fail;
149		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
150		if (n < 0)
151			fatal_perror("check_sysemu: wait failed");
152
153		if (WIFSTOPPED(status) &&
154		    (WSTOPSIG(status) == (SIGTRAP|0x80))) {
155			if (!count) {
156				non_fatal("check_sysemu: SYSEMU_SINGLESTEP "
157					  "doesn't singlestep");
158				goto fail;
159			}
160			n = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_RET_OFFSET,
161				   os_getpid());
162			if (n < 0)
163				fatal_perror("check_sysemu : failed to modify "
164					     "system call return");
165			break;
166		}
167		else if (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGTRAP))
168			count++;
169		else {
170			non_fatal("check_sysemu: expected SIGTRAP or "
171				  "(SIGTRAP | 0x80), got status = %d\n",
172				  status);
173			goto fail;
174		}
175	}
176	stop_ptraced_child(pid, 0);
 
177
178	os_info("OK\n");
 
179
 
 
180	return;
181
182fail:
183	stop_ptraced_child(pid, 1);
184	fatal("missing\n");
 
185}
186
187static void __init check_ptrace(void)
188{
189	int pid, syscall, n, status;
190
191	os_info("Checking that ptrace can change system call numbers...");
192	pid = start_ptraced_child();
193
194	if ((ptrace(PTRACE_SETOPTIONS, pid, 0,
195		   (void *) PTRACE_O_TRACESYSGOOD) < 0))
196		fatal_perror("check_ptrace: PTRACE_SETOPTIONS failed");
197
198	while (1) {
199		if (ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0)
200			fatal_perror("check_ptrace : ptrace failed");
201
202		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
203		if (n < 0)
204			fatal_perror("check_ptrace : wait failed");
205
206		if (!WIFSTOPPED(status) ||
207		   (WSTOPSIG(status) != (SIGTRAP | 0x80)))
208			fatal("check_ptrace : expected (SIGTRAP|0x80), "
209			       "got status = %d", status);
210
211		syscall = ptrace(PTRACE_PEEKUSER, pid, PT_SYSCALL_NR_OFFSET,
212				 0);
213		if (syscall == __NR_getpid) {
214			n = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_NR_OFFSET,
215				   __NR_getppid);
216			if (n < 0)
217				fatal_perror("check_ptrace : failed to modify "
218					     "system call");
219			break;
220		}
221	}
222	stop_ptraced_child(pid, 0);
223	os_info("OK\n");
224	check_sysemu();
225}
226
 
 
227static void __init check_coredump_limit(void)
228{
229	struct rlimit lim;
230	int err = getrlimit(RLIMIT_CORE, &lim);
231
232	if (err) {
233		perror("Getting core dump limit");
234		return;
235	}
236
237	os_info("Core dump limits :\n\tsoft - ");
238	if (lim.rlim_cur == RLIM_INFINITY)
239		os_info("NONE\n");
240	else
241		os_info("%llu\n", (unsigned long long)lim.rlim_cur);
242
243	os_info("\thard - ");
244	if (lim.rlim_max == RLIM_INFINITY)
245		os_info("NONE\n");
246	else
247		os_info("%llu\n", (unsigned long long)lim.rlim_max);
248}
249
250void  __init get_host_cpu_features(
251		void (*flags_helper_func)(char *line),
252		void (*cache_helper_func)(char *line))
253{
254	FILE *cpuinfo;
255	char *line = NULL;
256	size_t len = 0;
257	int done_parsing = 0;
258
259	cpuinfo = fopen("/proc/cpuinfo", "r");
260	if (cpuinfo == NULL) {
261		os_info("Failed to get host CPU features\n");
262	} else {
263		while ((getline(&line, &len, cpuinfo)) != -1) {
264			if (strstr(line, "flags")) {
265				flags_helper_func(line);
266				done_parsing++;
267			}
268			if (strstr(line, "cache_alignment")) {
269				cache_helper_func(line);
270				done_parsing++;
271			}
272			free(line);
273			line = NULL;
274			if (done_parsing > 1)
275				break;
276		}
277		fclose(cpuinfo);
278	}
279}
280
281
282void __init os_early_checks(void)
283{
284	int pid;
285
286	/* Print out the core dump limits early */
287	check_coredump_limit();
288
289	check_ptrace();
290
291	/* Need to check this early because mmapping happens before the
292	 * kernel is running.
293	 */
294	check_tmpexec();
295
296	pid = start_ptraced_child();
297	if (init_pid_registers(pid))
298		fatal("Failed to initialize default registers");
299	stop_ptraced_child(pid, 1);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
300}
301
302int __init parse_iomem(char *str, int *add)
303{
304	struct iomem_region *new;
305	struct stat64 buf;
306	char *file, *driver;
307	int fd, size;
308
309	driver = str;
310	file = strchr(str,',');
311	if (file == NULL) {
312		os_warn("parse_iomem : failed to parse iomem\n");
313		goto out;
314	}
315	*file = '\0';
316	file++;
317	fd = open(file, O_RDWR, 0);
318	if (fd < 0) {
319		perror("parse_iomem - Couldn't open io file");
320		goto out;
321	}
322
323	if (fstat64(fd, &buf) < 0) {
324		perror("parse_iomem - cannot stat_fd file");
325		goto out_close;
326	}
327
328	new = malloc(sizeof(*new));
329	if (new == NULL) {
330		perror("Couldn't allocate iomem_region struct");
331		goto out_close;
332	}
333
334	size = (buf.st_size + UM_KERN_PAGE_SIZE) & ~(UM_KERN_PAGE_SIZE - 1);
335
336	*new = ((struct iomem_region) { .next		= iomem_regions,
337					.driver		= driver,
338					.fd		= fd,
339					.size		= size,
340					.phys		= 0,
341					.virt		= 0 });
342	iomem_regions = new;
343	iomem_size += new->size + UM_KERN_PAGE_SIZE;
344
345	return 0;
346 out_close:
347	close(fd);
348 out:
349	return 1;
350}