blob: 387e26af301a57c6ca0a861c654727af7a5b3696 [file] [log] [blame]
Gennady Sharapov60d339f62005-09-03 15:57:47 -07001/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
3 * Licensed under the GPL
4 */
5
Jeff Dike8e367062006-03-27 01:14:32 -08006#include <pty.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007#include <stdio.h>
Jeff Dike0f80bc82005-09-16 19:27:50 -07008#include <stddef.h>
9#include <stdarg.h>
10#include <stdlib.h>
11#include <string.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <unistd.h>
13#include <signal.h>
14#include <sched.h>
Jeff Dike0f80bc82005-09-16 19:27:50 -070015#include <fcntl.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <errno.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <setjmp.h>
18#include <sys/time.h>
19#include <sys/wait.h>
20#include <sys/mman.h>
21#include <asm/unistd.h>
22#include <asm/page.h>
Jeff Dike0f80bc82005-09-16 19:27:50 -070023#include <sys/types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include "user_util.h"
25#include "kern_util.h"
26#include "user.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include "signal_kern.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include "sysdep/ptrace.h"
29#include "sysdep/sigcontext.h"
30#include "irq_user.h"
31#include "ptrace_user.h"
Jeff Dike0f80bc82005-09-16 19:27:50 -070032#include "mem_user.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include "init.h"
34#include "os.h"
35#include "uml-config.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include "choose-mode.h"
37#include "mode.h"
Jeff Diked67b5692005-07-07 17:56:49 -070038#include "tempfile.h"
Jeff Dike0f80bc82005-09-16 19:27:50 -070039#include "kern_constants.h"
40
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#ifdef UML_CONFIG_MODE_SKAS
42#include "skas.h"
43#include "skas_ptrace.h"
44#include "registers.h"
45#endif
46
Jeff Dikeb85e9682005-07-28 21:16:01 -070047static int ptrace_child(void *arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -070048{
49 int ret;
50 int pid = os_getpid(), ppid = getppid();
51 int sc_result;
52
Jeff Dike43b00fd2006-02-07 12:58:42 -080053 change_sig(SIGWINCH, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 if(ptrace(PTRACE_TRACEME, 0, 0, 0) < 0){
55 perror("ptrace");
56 os_kill_process(pid, 0);
57 }
58 os_stop_process(pid);
59
60 /*This syscall will be intercepted by the parent. Don't call more than
61 * once, please.*/
62 sc_result = os_getpid();
63
64 if (sc_result == pid)
65 ret = 1; /*Nothing modified by the parent, we are running
66 normally.*/
67 else if (sc_result == ppid)
68 ret = 0; /*Expected in check_ptrace and check_sysemu when they
69 succeed in modifying the stack frame*/
70 else
71 ret = 2; /*Serious trouble! This could be caused by a bug in
72 host 2.6 SKAS3/2.6 patch before release -V6, together
73 with a bug in the UML code itself.*/
74 _exit(ret);
75}
76
Jeff Dikeb85e9682005-07-28 21:16:01 -070077static int start_ptraced_child(void **stack_out)
Linus Torvalds1da177e2005-04-16 15:20:36 -070078{
Jeff Dikeb85e9682005-07-28 21:16:01 -070079 void *stack;
80 unsigned long sp;
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 int pid, n, status;
Gennady Sharapov60d339f62005-09-03 15:57:47 -070082
Jeff Dikeb85e9682005-07-28 21:16:01 -070083 stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
84 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
85 if(stack == MAP_FAILED)
86 panic("check_ptrace : mmap failed, errno = %d", errno);
87 sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
88 pid = clone(ptrace_child, (void *) sp, SIGCHLD, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 if(pid < 0)
Gennady Sharapov60d339f62005-09-03 15:57:47 -070090 panic("start_ptraced_child : clone failed, errno = %d", errno);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
92 if(n < 0)
Gennady Sharapov60d339f62005-09-03 15:57:47 -070093 panic("check_ptrace : clone failed, errno = %d", errno);
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
95 panic("check_ptrace : expected SIGSTOP, got status = %d",
96 status);
97
Jeff Dikeb85e9682005-07-28 21:16:01 -070098 *stack_out = stack;
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 return(pid);
100}
101
Gennady Sharapov60d339f62005-09-03 15:57:47 -0700102/* When testing for SYSEMU support, if it is one of the broken versions, we
103 * must just avoid using sysemu, not panic, but only if SYSEMU features are
104 * broken.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 * So only for SYSEMU features we test mustpanic, while normal host features
Gennady Sharapov60d339f62005-09-03 15:57:47 -0700106 * must work anyway!
107 */
108static int stop_ptraced_child(int pid, void *stack, int exitcode,
109 int mustpanic)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110{
111 int status, n, ret = 0;
112
113 if(ptrace(PTRACE_CONT, pid, 0, 0) < 0)
Jeff Dikeb85e9682005-07-28 21:16:01 -0700114 panic("check_ptrace : ptrace failed, errno = %d", errno);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 CATCH_EINTR(n = waitpid(pid, &status, 0));
116 if(!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) {
117 int exit_with = WEXITSTATUS(status);
118 if (exit_with == 2)
Paolo 'Blaisorblade' Giarrusso51694942005-12-29 17:39:51 +0100119 printf("check_ptrace : child exited with status 2. "
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 "Serious trouble happening! Try updating your "
121 "host skas patch!\nDisabling SYSEMU support.");
Paolo 'Blaisorblade' Giarrusso51694942005-12-29 17:39:51 +0100122 printf("check_ptrace : child exited with exitcode %d, while "
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 "expecting %d; status 0x%x", exit_with,
124 exitcode, status);
Jeff Dikeb85e9682005-07-28 21:16:01 -0700125 if (mustpanic)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 panic("\n");
127 else
Paolo 'Blaisorblade' Giarrusso51694942005-12-29 17:39:51 +0100128 printf("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 ret = -1;
130 }
131
Jeff Dikeb85e9682005-07-28 21:16:01 -0700132 if(munmap(stack, PAGE_SIZE) < 0)
133 panic("check_ptrace : munmap failed, errno = %d", errno);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 return ret;
135}
136
Paolo 'Blaisorblade' Giarrussocb665042005-07-27 11:43:31 -0700137int ptrace_faultinfo = 1;
Bodo Stroesser858259c2005-11-07 00:58:55 -0800138int ptrace_ldt = 1;
Paolo 'Blaisorblade' Giarrussocb665042005-07-27 11:43:31 -0700139int proc_mm = 1;
Bodo Stroesser858259c2005-11-07 00:58:55 -0800140int skas_needs_stub = 0;
Paolo 'Blaisorblade' Giarrussocb665042005-07-27 11:43:31 -0700141
142static int __init skas0_cmd_param(char *str, int* add)
143{
144 ptrace_faultinfo = proc_mm = 0;
145 return 0;
146}
147
Paolo 'Blaisorblade' Giarrusso9e3d8622005-10-09 21:37:18 +0200148/* The two __uml_setup would conflict, without this stupid alias. */
149
150static int __init mode_skas0_cmd_param(char *str, int* add)
151 __attribute__((alias("skas0_cmd_param")));
152
Gennady Sharapov60d339f62005-09-03 15:57:47 -0700153__uml_setup("skas0", skas0_cmd_param,
154 "skas0\n"
155 " Disables SKAS3 usage, so that SKAS0 is used, unless \n"
156 " you specify mode=tt.\n\n");
157
Paolo 'Blaisorblade' Giarrusso9e3d8622005-10-09 21:37:18 +0200158__uml_setup("mode=skas0", mode_skas0_cmd_param,
159 "mode=skas0\n"
160 " Disables SKAS3 usage, so that SKAS0 is used, unless you \n"
161 " specify mode=tt. Note that this was recently added - on \n"
162 " older kernels you must use simply \"skas0\".\n\n");
163
Gennady Sharapov60d339f62005-09-03 15:57:47 -0700164static int force_sysemu_disabled = 0;
165
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166static int __init nosysemu_cmd_param(char *str, int* add)
167{
168 force_sysemu_disabled = 1;
169 return 0;
170}
171
172__uml_setup("nosysemu", nosysemu_cmd_param,
Gennady Sharapov60d339f62005-09-03 15:57:47 -0700173"nosysemu\n"
174" Turns off syscall emulation patch for ptrace (SYSEMU) on.\n"
175" SYSEMU is a performance-patch introduced by Laurent Vivier. It changes\n"
176" behaviour of ptrace() and helps reducing host context switch rate.\n"
177" To make it working, you need a kernel patch for your host, too.\n"
178" See http://perso.wanadoo.fr/laurent.vivier/UML/ for further \n"
179" information.\n\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180
181static void __init check_sysemu(void)
182{
Jeff Dikeb85e9682005-07-28 21:16:01 -0700183 void *stack;
Bodo Stroesserf9dfefe2005-09-03 15:57:51 -0700184 int pid, n, status, count=0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185
Paolo 'Blaisorblade' Giarrusso51694942005-12-29 17:39:51 +0100186 printf("Checking syscall emulation patch for ptrace...");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 sysemu_supported = 0;
Jeff Dikeb85e9682005-07-28 21:16:01 -0700188 pid = start_ptraced_child(&stack);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189
190 if(ptrace(PTRACE_SYSEMU, pid, 0, 0) < 0)
191 goto fail;
192
193 CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
194 if (n < 0)
195 panic("check_sysemu : wait failed, errno = %d", errno);
196 if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
197 panic("check_sysemu : expected SIGTRAP, "
198 "got status = %d", status);
199
200 n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET,
201 os_getpid());
202 if(n < 0)
203 panic("check_sysemu : failed to modify system "
204 "call return, errno = %d", errno);
205
Jeff Dikeb85e9682005-07-28 21:16:01 -0700206 if (stop_ptraced_child(pid, stack, 0, 0) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 goto fail_stopped;
208
209 sysemu_supported = 1;
Paolo 'Blaisorblade' Giarrusso51694942005-12-29 17:39:51 +0100210 printf("OK\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 set_using_sysemu(!force_sysemu_disabled);
212
Paolo 'Blaisorblade' Giarrusso51694942005-12-29 17:39:51 +0100213 printf("Checking advanced syscall emulation patch for ptrace...");
Jeff Dikeb85e9682005-07-28 21:16:01 -0700214 pid = start_ptraced_child(&stack);
Bodo Stroesserf9dfefe2005-09-03 15:57:51 -0700215
216 if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
217 (void *) PTRACE_O_TRACESYSGOOD) < 0)
218 panic("check_ptrace: PTRACE_OLDSETOPTIONS failed, errno = %d",
219 errno);
220
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 while(1){
222 count++;
223 if(ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0)
224 goto fail;
225 CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
226 if(n < 0)
227 panic("check_ptrace : wait failed, errno = %d", errno);
Bodo Stroesserf9dfefe2005-09-03 15:57:51 -0700228 if(WIFSTOPPED(status) && (WSTOPSIG(status) == (SIGTRAP|0x80))){
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 if (!count)
Bodo Stroesserf9dfefe2005-09-03 15:57:51 -0700230 panic("check_ptrace : SYSEMU_SINGLESTEP "
231 "doesn't singlestep");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET,
233 os_getpid());
234 if(n < 0)
235 panic("check_sysemu : failed to modify system "
236 "call return, errno = %d", errno);
237 break;
238 }
Bodo Stroesserf9dfefe2005-09-03 15:57:51 -0700239 else if(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGTRAP))
240 count++;
241 else
242 panic("check_ptrace : expected SIGTRAP or "
243 "(SIGTRAP|0x80), got status = %d", status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 }
Jeff Dikeb85e9682005-07-28 21:16:01 -0700245 if (stop_ptraced_child(pid, stack, 0, 0) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 goto fail_stopped;
247
248 sysemu_supported = 2;
Paolo 'Blaisorblade' Giarrusso51694942005-12-29 17:39:51 +0100249 printf("OK\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250
251 if ( !force_sysemu_disabled )
252 set_using_sysemu(sysemu_supported);
253 return;
254
255fail:
Jeff Dikeb85e9682005-07-28 21:16:01 -0700256 stop_ptraced_child(pid, stack, 1, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257fail_stopped:
Paolo 'Blaisorblade' Giarrusso51694942005-12-29 17:39:51 +0100258 printf("missing\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259}
260
Gennady Sharapov60d339f62005-09-03 15:57:47 -0700261static void __init check_ptrace(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262{
Jeff Dikeb85e9682005-07-28 21:16:01 -0700263 void *stack;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 int pid, syscall, n, status;
265
Paolo 'Blaisorblade' Giarrusso51694942005-12-29 17:39:51 +0100266 printf("Checking that ptrace can change system call numbers...");
Jeff Dikeb85e9682005-07-28 21:16:01 -0700267 pid = start_ptraced_child(&stack);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268
Gennady Sharapov60d339f62005-09-03 15:57:47 -0700269 if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0)
270 panic("check_ptrace: PTRACE_OLDSETOPTIONS failed, errno = %d", errno);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271
272 while(1){
273 if(ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0)
Gennady Sharapov60d339f62005-09-03 15:57:47 -0700274 panic("check_ptrace : ptrace failed, errno = %d",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 errno);
276 CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
277 if(n < 0)
278 panic("check_ptrace : wait failed, errno = %d", errno);
Bodo Stroesserf9dfefe2005-09-03 15:57:51 -0700279 if(!WIFSTOPPED(status) || (WSTOPSIG(status) != (SIGTRAP|0x80)))
280 panic("check_ptrace : expected (SIGTRAP|0x80), "
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 "got status = %d", status);
Gennady Sharapov60d339f62005-09-03 15:57:47 -0700282
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET,
284 0);
285 if(syscall == __NR_getpid){
286 n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET,
287 __NR_getppid);
288 if(n < 0)
289 panic("check_ptrace : failed to modify system "
290 "call, errno = %d", errno);
291 break;
292 }
293 }
Jeff Dikeb85e9682005-07-28 21:16:01 -0700294 stop_ptraced_child(pid, stack, 0, 1);
Paolo 'Blaisorblade' Giarrusso51694942005-12-29 17:39:51 +0100295 printf("OK\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 check_sysemu();
297}
298
Jeff Dikeae173812005-11-07 00:58:57 -0800299extern int create_tmp_file(unsigned long long len);
Jeff Dike0f80bc82005-09-16 19:27:50 -0700300
301static void check_tmpexec(void)
302{
303 void *addr;
304 int err, fd = create_tmp_file(UM_KERN_PAGE_SIZE);
305
306 addr = mmap(NULL, UM_KERN_PAGE_SIZE,
307 PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, fd, 0);
308 printf("Checking PROT_EXEC mmap in /tmp...");
309 fflush(stdout);
310 if(addr == MAP_FAILED){
311 err = errno;
312 perror("failed");
313 if(err == EPERM)
314 printf("/tmp must be not mounted noexec\n");
315 exit(1);
316 }
317 printf("OK\n");
318 munmap(addr, UM_KERN_PAGE_SIZE);
319
320 close(fd);
321}
322
Gennady Sharapov60d339f62005-09-03 15:57:47 -0700323void os_early_checks(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324{
Gennady Sharapov60d339f62005-09-03 15:57:47 -0700325 check_ptrace();
Jeff Dike0f80bc82005-09-16 19:27:50 -0700326
327 /* Need to check this early because mmapping happens before the
328 * kernel is running.
329 */
330 check_tmpexec();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331}
332
Bodo Stroesserd9838d82005-09-03 15:57:51 -0700333static int __init noprocmm_cmd_param(char *str, int* add)
334{
335 proc_mm = 0;
336 return 0;
337}
338
339__uml_setup("noprocmm", noprocmm_cmd_param,
340"noprocmm\n"
341" Turns off usage of /proc/mm, even if host supports it.\n"
342" To support /proc/mm, the host needs to be patched using\n"
343" the current skas3 patch.\n\n");
344
345static int __init noptracefaultinfo_cmd_param(char *str, int* add)
346{
347 ptrace_faultinfo = 0;
348 return 0;
349}
350
351__uml_setup("noptracefaultinfo", noptracefaultinfo_cmd_param,
352"noptracefaultinfo\n"
353" Turns off usage of PTRACE_FAULTINFO, even if host supports\n"
354" it. To support PTRACE_FAULTINFO, the host needs to be patched\n"
355" using the current skas3 patch.\n\n");
356
Bodo Stroesser858259c2005-11-07 00:58:55 -0800357static int __init noptraceldt_cmd_param(char *str, int* add)
358{
359 ptrace_ldt = 0;
360 return 0;
361}
362
363__uml_setup("noptraceldt", noptraceldt_cmd_param,
364"noptraceldt\n"
365" Turns off usage of PTRACE_LDT, even if host supports it.\n"
366" To support PTRACE_LDT, the host needs to be patched using\n"
367" the current skas3 patch.\n\n");
368
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369#ifdef UML_CONFIG_MODE_SKAS
Bodo Stroesser858259c2005-11-07 00:58:55 -0800370static inline void check_skas3_ptrace_faultinfo(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371{
372 struct ptrace_faultinfo fi;
Jeff Dikeb85e9682005-07-28 21:16:01 -0700373 void *stack;
Jeff Diked67b5692005-07-07 17:56:49 -0700374 int pid, n;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375
Bodo Stroesser858259c2005-11-07 00:58:55 -0800376 printf(" - PTRACE_FAULTINFO...");
Jeff Dikeb85e9682005-07-28 21:16:01 -0700377 pid = start_ptraced_child(&stack);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378
379 n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi);
380 if (n < 0) {
Paolo 'Blaisorblade' Giarrussocb665042005-07-27 11:43:31 -0700381 ptrace_faultinfo = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 if(errno == EIO)
383 printf("not found\n");
Gennady Sharapov60d339f62005-09-03 15:57:47 -0700384 else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 perror("not found");
Jeff Diked67b5692005-07-07 17:56:49 -0700386 }
387 else {
Paolo 'Blaisorblade' Giarrussocb665042005-07-27 11:43:31 -0700388 if (!ptrace_faultinfo)
389 printf("found but disabled on command line\n");
390 else
391 printf("found\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 }
393
394 init_registers(pid);
Jeff Dikeb85e9682005-07-28 21:16:01 -0700395 stop_ptraced_child(pid, stack, 1, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396}
397
Bodo Stroesser858259c2005-11-07 00:58:55 -0800398static inline void check_skas3_ptrace_ldt(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399{
Bodo Stroesser858259c2005-11-07 00:58:55 -0800400#ifdef PTRACE_LDT
401 void *stack;
402 int pid, n;
403 unsigned char ldtbuf[40];
404 struct ptrace_ldt ldt_op = (struct ptrace_ldt) {
405 .func = 2, /* read default ldt */
406 .ptr = ldtbuf,
407 .bytecount = sizeof(ldtbuf)};
408
409 printf(" - PTRACE_LDT...");
410 pid = start_ptraced_child(&stack);
411
412 n = ptrace(PTRACE_LDT, pid, 0, (unsigned long) &ldt_op);
413 if (n < 0) {
414 if(errno == EIO)
415 printf("not found\n");
416 else {
417 perror("not found");
418 }
419 ptrace_ldt = 0;
420 }
421 else {
422 if(ptrace_ldt)
423 printf("found\n");
424 else
425 printf("found, but use is disabled\n");
426 }
427
428 stop_ptraced_child(pid, stack, 1, 1);
429#else
430 /* PTRACE_LDT might be disabled via cmdline option.
431 * We want to override this, else we might use the stub
432 * without real need
433 */
434 ptrace_ldt = 1;
435#endif
436}
437
438static inline void check_skas3_proc_mm(void)
439{
440 printf(" - /proc/mm...");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 if (os_access("/proc/mm", OS_ACC_W_OK) < 0) {
Gennady Sharapov60d339f62005-09-03 15:57:47 -0700442 proc_mm = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 printf("not found\n");
Gennady Sharapov60d339f62005-09-03 15:57:47 -0700444 }
445 else {
Paolo 'Blaisorblade' Giarrussocb665042005-07-27 11:43:31 -0700446 if (!proc_mm)
447 printf("found but disabled on command line\n");
448 else
449 printf("found\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450 }
Bodo Stroesser858259c2005-11-07 00:58:55 -0800451}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452
Bodo Stroesser858259c2005-11-07 00:58:55 -0800453int can_do_skas(void)
454{
455 printf("Checking for the skas3 patch in the host:\n");
456
457 check_skas3_proc_mm();
458 check_skas3_ptrace_faultinfo();
459 check_skas3_ptrace_ldt();
460
461 if(!proc_mm || !ptrace_faultinfo || !ptrace_ldt)
462 skas_needs_stub = 1;
463
Jeff Diked67b5692005-07-07 17:56:49 -0700464 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465}
466#else
467int can_do_skas(void)
468{
469 return(0);
470}
471#endif
Jeff Dike0f80bc82005-09-16 19:27:50 -0700472
Jeff Dike0f80bc82005-09-16 19:27:50 -0700473int __init parse_iomem(char *str, int *add)
474{
475 struct iomem_region *new;
476 struct uml_stat buf;
477 char *file, *driver;
478 int fd, err, size;
479
480 driver = str;
481 file = strchr(str,',');
482 if(file == NULL){
483 printf("parse_iomem : failed to parse iomem\n");
484 goto out;
485 }
486 *file = '\0';
487 file++;
488 fd = os_open_file(file, of_rdwr(OPENFLAGS()), 0);
489 if(fd < 0){
490 os_print_error(fd, "parse_iomem - Couldn't open io file");
491 goto out;
492 }
493
494 err = os_stat_fd(fd, &buf);
495 if(err < 0){
496 os_print_error(err, "parse_iomem - cannot stat_fd file");
497 goto out_close;
498 }
499
500 new = malloc(sizeof(*new));
501 if(new == NULL){
502 perror("Couldn't allocate iomem_region struct");
503 goto out_close;
504 }
505
506 size = (buf.ust_size + UM_KERN_PAGE_SIZE) & ~(UM_KERN_PAGE_SIZE - 1);
507
508 *new = ((struct iomem_region) { .next = iomem_regions,
509 .driver = driver,
510 .fd = fd,
511 .size = size,
512 .phys = 0,
513 .virt = 0 });
514 iomem_regions = new;
515 iomem_size += new->size + UM_KERN_PAGE_SIZE;
516
517 return(0);
518 out_close:
519 os_close_file(fd);
520 out:
521 return(1);
522}
523
Jeff Dike8e367062006-03-27 01:14:32 -0800524
525/* Changed during early boot */
526int pty_output_sigio = 0;
527int pty_close_sigio = 0;
528
529/* Used as a flag during SIGIO testing early in boot */
530static volatile int got_sigio = 0;
531
532static void __init handler(int sig)
533{
534 got_sigio = 1;
535}
536
537struct openpty_arg {
538 int master;
539 int slave;
540 int err;
541};
542
543static void openpty_cb(void *arg)
544{
545 struct openpty_arg *info = arg;
546
547 info->err = 0;
548 if(openpty(&info->master, &info->slave, NULL, NULL, NULL))
549 info->err = -errno;
550}
551
552static void __init check_one_sigio(void (*proc)(int, int))
553{
554 struct sigaction old, new;
555 struct openpty_arg pty = { .master = -1, .slave = -1 };
556 int master, slave, err;
557
558 initial_thread_cb(openpty_cb, &pty);
559 if(pty.err){
560 printk("openpty failed, errno = %d\n", -pty.err);
561 return;
562 }
563
564 master = pty.master;
565 slave = pty.slave;
566
567 if((master == -1) || (slave == -1)){
568 printk("openpty failed to allocate a pty\n");
569 return;
570 }
571
572 /* Not now, but complain so we now where we failed. */
573 err = raw(master);
574 if (err < 0)
575 panic("check_sigio : __raw failed, errno = %d\n", -err);
576
577 err = os_sigio_async(master, slave);
578 if(err < 0)
579 panic("tty_fds : sigio_async failed, err = %d\n", -err);
580
581 if(sigaction(SIGIO, NULL, &old) < 0)
582 panic("check_sigio : sigaction 1 failed, errno = %d\n", errno);
583 new = old;
584 new.sa_handler = handler;
585 if(sigaction(SIGIO, &new, NULL) < 0)
586 panic("check_sigio : sigaction 2 failed, errno = %d\n", errno);
587
588 got_sigio = 0;
589 (*proc)(master, slave);
590
591 close(master);
592 close(slave);
593
594 if(sigaction(SIGIO, &old, NULL) < 0)
595 panic("check_sigio : sigaction 3 failed, errno = %d\n", errno);
596}
597
598static void tty_output(int master, int slave)
599{
600 int n;
601 char buf[512];
602
603 printk("Checking that host ptys support output SIGIO...");
604
605 memset(buf, 0, sizeof(buf));
606
607 while(os_write_file(master, buf, sizeof(buf)) > 0) ;
608 if(errno != EAGAIN)
609 panic("check_sigio : write failed, errno = %d\n", errno);
610 while(((n = os_read_file(slave, buf, sizeof(buf))) > 0) && !got_sigio) ;
611
612 if(got_sigio){
613 printk("Yes\n");
614 pty_output_sigio = 1;
615 }
616 else if(n == -EAGAIN) printk("No, enabling workaround\n");
617 else panic("check_sigio : read failed, err = %d\n", n);
618}
619
620static void tty_close(int master, int slave)
621{
622 printk("Checking that host ptys support SIGIO on close...");
623
624 close(slave);
625 if(got_sigio){
626 printk("Yes\n");
627 pty_close_sigio = 1;
628 }
629 else printk("No, enabling workaround\n");
630}
631
632void __init check_sigio(void)
633{
634 if((os_access("/dev/ptmx", OS_ACC_R_OK) < 0) &&
635 (os_access("/dev/ptyp0", OS_ACC_R_OK) < 0)){
636 printk("No pseudo-terminals available - skipping pty SIGIO "
637 "check\n");
638 return;
639 }
640 check_one_sigio(tty_output);
641 check_one_sigio(tty_close);
642}
643
644void os_check_bugs(void)
645{
646 check_ptrace();
647 check_sigio();
Jeff Dike8e367062006-03-27 01:14:32 -0800648}
649