96_allow_multiple_console_output.patch

   1 Description: Allow multiple console output
   2  When booting a kernel with multiple serial console support, or multuiple
   3  console arguments ala "console=tty1 console=ttyS0,9600" the kernel will output
   4  messages to all consoles, init however will not. It will only send output to,
   5  and accept input from, the last of the consoles.
   6  .
   7  This patch fixes it.
   8 Author: Martin Buck <m@rtin-buck.de>
   9 Origin: other, https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=181756
  10 Bug-Debian: https://bugs.debian.org/181756
  11 Forwarded: no
  12 Last-Update: 2014-07-20
  13
  14 Index: sysvinit-2.88dsf/src/bootlogd.c
  15 ===================================================================
  16 --- sysvinit-2.88dsf.orig/src/bootlogd.c        2010-03-23 15:37:01.000000000 +0100
  17 +++ sysvinit-2.88dsf/src/bootlogd.c     2013-07-15 09:56:55.953975300 +0200
  18 @@ -57,6 +57,7 @@
  19  char *Version = "@(#) bootlogd 2.86 03-Jun-2004 miquels@cistron.nl";
  20
  21  #define LOGFILE        "/var/log/boot"
  22 +#define MAX_CONSOLES 16
  23
  24  char ringbuf[32768];
  25  char *endptr = ringbuf + sizeof(ringbuf);
  26 @@ -73,6 +74,11 @@
  27         int pos;
  28  } line;
  29
  30 +struct real_cons {
  31 +       char name[1024];
  32 +       int fd;
  33 +};
  34 +
  35  /*
  36   *     Console devices as listed on the kernel command line and
  37   *     the mapping to actual devices in /dev
  38 @@ -235,10 +241,10 @@
  39  }
  40
  41  /*
  42 - *     Find out the _real_ console. Assume that stdin is connected to
  43 + *     Find out the _real_ console(s). Assume that stdin is connected to
  44   *     the console device (/dev/console).
  45   */
  46 -int consolename(char *res, int rlen)
  47 +int consolenames(struct real_cons *cons, int max_consoles)
  48  {
  49  #ifdef TIOCGDEV
  50         unsigned int    kdev;
  51 @@ -247,34 +253,9 @@
  52         char            buf[256];
  53         char            *p;
  54         int             didmount = 0;
  55 -       int             n, r;
  56 +       int             n;
  57         int             fd;
  58 -
  59 -       fstat(0, &st);
  60 -       if (major(st.st_rdev) != 5 || minor(st.st_rdev) != 1) {
  61 -               /*
  62 -                *      Old kernel, can find real device easily.
  63 -                */
  64 -               int r = findtty(res, "/dev", rlen, st.st_rdev);
  65 -               if (0 != r)
  66 -                       fprintf(stderr, "bootlogd: cannot find console device "
  67 -                               "%d:%d under /dev\n", major(st.st_rdev), minor(st.st_rdev));
  68 -               return r;
  69 -       }
  70 -
  71 -#ifdef TIOCGDEV
  72 -# ifndef  ENOIOCTLCMD
  73 -#  define ENOIOCTLCMD  515
  74 -# endif
  75 -       if (ioctl(0, TIOCGDEV, &kdev) == 0) {
  76 -               int r = findtty(res, "/dev", rlen, (dev_t)kdev);
  77 -               if (0 != r)
  78 -                       fprintf(stderr, "bootlogd: cannot find console device "
  79 -                               "%d:%d under /dev\n", major(kdev), minor(kdev));
  80 -               return r;
  81 -       }
  82 -       if (errno != ENOIOCTLCMD) return -1;
  83 -#endif
  84 +       int             considx, num_consoles = 0;
  85
  86  #ifdef __linux__
  87         /*
  88 @@ -283,7 +264,7 @@
  89         stat("/", &st);
  90         if (stat("/proc", &st2) < 0) {
  91                 perror("bootlogd: /proc");
  92 -               return -1;
  93 +               return 0;
  94         }
  95         if (st.st_dev == st2.st_dev) {
  96                 if (mount("proc", "/proc", "proc", 0, NULL) < 0) {
  97 @@ -293,21 +274,21 @@
  98                 didmount = 1;
  99         }
 100
 101 -       n = 0;
 102 -       r = -1;
 103 +       n = -1;
 104         if ((fd = open("/proc/cmdline", O_RDONLY)) < 0) {
 105                 perror("bootlogd: /proc/cmdline");
 106         } else {
 107                 buf[0] = 0;
 108 -               if ((n = read(fd, buf, sizeof(buf) - 1)) >= 0)
 109 -                       r = 0;
 110 -               else
 111 +               if ((n = read(fd, buf, sizeof(buf) - 1)) < 0)
 112                         perror("bootlogd: /proc/cmdline");
 113                 close(fd);
 114         }
 115         if (didmount) umount("/proc");
 116 +
 117 +
 118 +       if (n < 0) return 0;
 119 +
 120
 121 -       if (r < 0) return r;
 122
 123         /*
 124          *      OK, so find console= in /proc/cmdline.
 125 @@ -315,21 +296,32 @@
 126          */
 127         p = buf + n;
 128         *p-- = 0;
 129 -       r = -1;
 130         while (p >= buf) {
 131                 if (*p == ' ' || *p == '\t' || *p == '\r' || *p == '\n') {
 132                         *p-- = 0;
 133                         continue;
 134                 }
 135                 if (strncmp(p, "console=", 8) == 0 &&
 136 -                   isconsole(p + 8, res, rlen)) {
 137 -                       r = 0;
 138 -                       break;
 139 +                       isconsole(p + 8, cons[num_consoles].name, sizeof(cons[num_consoles].name))) {
 140 +                               /*
 141 +                                *      Suppress duplicates
 142 +                                */
 143 +                               for (considx = 0; considx < num_consoles; considx++) {
 144 +                                       if (!strcmp(cons[num_consoles].name, cons[considx].name)) {
 145 +                                               goto dontuse;
 146 +                                       }
 147 +                               }
 148 +
 149 +                       num_consoles++;
 150 +                       if (num_consoles >= max_consoles) {
 151 +                               break;
 152 +                       }
 153                 }
 154 +dontuse:
 155                 p--;
 156         }
 157
 158 -       if (r == 0) return r;
 159 +       if (num_consoles > 0) return num_consoles;
 160  #endif
 161
 162         /*
 163 @@ -337,12 +329,12 @@
 164          *      guess the default console.
 165          */
 166         for (n = 0; defcons[n]; n++)
 167 -               if (isconsole(defcons[n], res, rlen))
 168 -                       return 0;
 169 +               if (isconsole(defcons[n], cons[0].name, sizeof(cons[0].name)))
 170 +                       return 1;
 171
 172         fprintf(stderr, "bootlogd: cannot deduce real console device\n");
 173
 174 -       return -1;
 175 +       return 0;
 176  }
 177
 178
 179 @@ -472,7 +464,6 @@
 180         struct timeval  tv;
 181         fd_set          fds;
 182         char            buf[1024];
 183 -       char            realcons[1024];
 184         char            *p;
 185         char            *logfile;
 186         char            *pidfile;
 187 @@ -485,6 +476,9 @@
 188  #ifndef __linux__      /* BSD-style ioctl needs an argument. */
 189         int             on = 1;
 190  #endif
 191 +       int             considx;
 192 +       struct real_cons cons[MAX_CONSOLES];
 193 +       int             num_consoles, consoles_left;
 194
 195         fp = NULL;
 196         logfile = LOGFILE;
 197 @@ -531,18 +525,22 @@
 198         /*
 199          *      Open console device directly.
 200          */
 201 -       if (consolename(realcons, sizeof(realcons)) < 0)
 202 -               return 1;
 203 -
 204 -       if (strcmp(realcons, "/dev/tty0") == 0)
 205 -               strcpy(realcons, "/dev/tty1");
 206 -       if (strcmp(realcons, "/dev/vc/0") == 0)
 207 -               strcpy(realcons, "/dev/vc/1");
 208 -
 209 -       if ((realfd = open_nb(realcons)) < 0) {
 210 -               fprintf(stderr, "bootlogd: %s: %s\n", buf, strerror(errno));
 211 +       if ((num_consoles = consolenames(cons, MAX_CONSOLES)) <= 0)
 212                 return 1;
 213 +       consoles_left = num_consoles;
 214 +       for (considx = 0; considx < num_consoles; considx++) {
 215 +               if (strcmp(cons[considx].name, "/dev/tty0") == 0)
 216 +                       strcpy(cons[considx].name, "/dev/tty1");
 217 +               if (strcmp(cons[considx].name, "/dev/vc/0") == 0)
 218 +                       strcpy(cons[considx].name, "/dev/vc/1");
 219 +
 220 +               if ((cons[considx].fd = open_nb(cons[considx].name)) < 0) {
 221 +                       fprintf(stderr, "bootlogd: %s: %s\n", cons[considx].name, strerror(errno));
 222 +                       consoles_left--;
 223 +               }
 224         }
 225 +       if (!consoles_left)
 226 +               return 1;
 227
 228         /*
 229          *      Grab a pty, and redirect console messages to it.
 230 @@ -626,26 +624,34 @@
 231                         if ((n = read(ptm, inptr, endptr - inptr)) >= 0) {
 232                                 /*
 233                                  *      Write data (in chunks if needed)
 234 -                                *      to the real output device.
 235 +                                *      to the real output devices.
 236                                  */
 237 -                               m = n;
 238 -                               p = inptr;
 239 -                               while (m > 0) {
 240 -                                       i = write(realfd, p, m);
 241 -                                       if (i >= 0) {
 242 -                                               m -= i;
 243 -                                               p += i;
 244 -                                               continue;
 245 -                                       }
 246 -                                       /*
 247 -                                        *      Handle EIO (somebody hung
 248 -                                        *      up our filedescriptor)
 249 -                                        */
 250 -                                       realfd = write_err(pts, realfd,
 251 -                                               realcons, errno);
 252 -                                       if (realfd >= 0) continue;
 253 -                                       got_signal = 1; /* Not really */
 254 -                                       break;
 255 +                               for (considx = 0; considx < num_consoles; considx++) {
 256 +                                       if (cons[considx].fd < 0) continue;
 257 +                                       m = n;
 258 +                                       p = inptr;
 259 +                                       while (m > 0) {
 260 +                                               i = write(cons[considx].fd, p, m);
 261 +                                               if (i >= 0) {
 262 +                                                       m -= i;
 263 +                                                       p += i;
 264 +                                                       continue;
 265 +                                               }
 266 +                                               /*
 267 +                                                *      Handle EIO (somebody hung
 268 +                                                *      up our filedescriptor)
 269 +                                                */
 270 +                                               cons[considx].fd = write_err(pts,
 271 +                                                       cons[considx].fd,
 272 +                                                       cons[considx].name, errno);
 273 +                                               if (cons[considx].fd >= 0) continue;
 274 +                                               /*
 275 +                                                *      If this was the last console,
 276 +                                                *      generate a fake signal
 277 +                                                */
 278 +                                               if (--consoles_left <= 0) got_signal = 1;
 279 +                                               break;
 280 +                                       }
 281                                 }
 282
 283                                 /*
 284 @@ -691,7 +697,9 @@
 285
 286         close(pts);
 287         close(ptm);
 288 -       close(realfd);
 289 +       for (considx = 0; considx < num_consoles; considx++) {
 290 +               close(cons[considx].fd);
 291 +       }
 292
 293         return 0;
 294  }