diff options
| -rw-r--r-- | configure.ac | 13 | ||||
| -rw-r--r-- | lib/consoles.c | 73 |
2 files changed, 86 insertions, 0 deletions
diff --git a/configure.ac b/configure.ac index 3be3715e5..c0783056c 100644 --- a/configure.ac +++ b/configure.ac @@ -1296,6 +1296,19 @@ if test "x$enable_use_tty_group" = xyes; then AC_DEFINE(USE_TTY_GROUP, 1, [Should wall and write be installed setgid tty?]) fi + +AC_ARG_ENABLE([sulogin-emergency-mount], + AS_HELP_STRING([--disable-sulogin-emergency-mount], + [do not use emergency mount of /dev and /proc for sulogin]), + [], enable_sulogin_emergency_mount=yes +) + +if test "x$enable_sulogin_emergency_mount" = xyes; then + AC_DEFINE(USE_SULOGIN_EMERGENCY_MOUNT, 1, + [Should sulogin use a emergency mount of /dev and /proc?]) +fi + + AC_ARG_ENABLE([makeinstall-chown], AS_HELP_STRING([--disable-makeinstall-chown], [do not do chown-like operations during "make install"]), [], enable_makeinstall_chown=yes diff --git a/lib/consoles.c b/lib/consoles.c index 21c5a249a..7175a0882 100644 --- a/lib/consoles.c +++ b/lib/consoles.c @@ -39,6 +39,16 @@ #include <dirent.h> #include <unistd.h> +#ifdef USE_SULOGIN_EMERGENCY_MOUNT +# include <sys/mount.h> +# include <linux/fs.h> +# include <linux/magic.h> +# include <linux/major.h> +# ifndef MNT_DETACH +# define MNT_DETACH 2 +# endif +#endif + #include "c.h" #include "canonicalize.h" #include "consoles.h" @@ -77,6 +87,64 @@ dbgprint(const char *mesg, ...) fputc('\n', stderr); } +#ifdef USE_SULOGIN_EMERGENCY_MOUNT +/* + * Make C library standard calls such like ttyname(3) work + * even if the system does not show any of the standard + * directories. + */ + +static uint32_t emergency_flags; +# define MNT_PROCFS 0x0001 +# define MNT_DEVTMPFS 0x0002 + +static __attribute__((__destructor__)) +void emergency_do_umounts(void) +{ + if (emergency_flags & MNT_DEVTMPFS) + umount2("/dev", MNT_DETACH); + if (emergency_flags & MNT_PROCFS) + umount2("/proc", MNT_DETACH); +} + +static __attribute__((__constructor__)) +void emergency_do_mounts(void) +{ + struct stat rt, xt; + + if (emergency_flags) { + emergency_flags = 0; + return; + } + + if (stat("/", &rt) != 0) { + warn("can not get file status of root file system\n"); + return; + } + + if (stat("/proc", &xt) == 0 + && rt.st_dev == xt.st_dev + && mount("proc", "/proc", "proc", MS_RELATIME, NULL) == 0) + emergency_flags |= MNT_PROCFS; + + if (stat("/dev", &xt) == 0 + && rt.st_dev == xt.st_dev + && mount("devtmpfs", "/dev", "devtmpfs", + MS_RELATIME, "mode=0755,nr_inodes=0") == 0) { + + emergency_flags |= MNT_DEVTMPFS; + mknod("/dev/console", S_IFCHR|S_IRUSR|S_IWUSR, + makedev(TTYAUX_MAJOR, 1)); + + if (symlink("/proc/self/fd", "/dev/fd") == 0) { + ignore_result( symlink("fd/0", "/dev/stdin") ); + ignore_result( symlink("fd/1", "/dev/stdout") ); + ignore_result( symlink("fd/2", "/dev/stderr") ); + } + } +} +#endif /* USE_SULOGIN_EMERGENCY_MOUNT */ + /* * Read and allocate one line from file, * the caller has to free the result @@ -182,6 +250,11 @@ char* scandev(DIR *dir, dev_t comparedev) continue; if ((size_t)snprintf(path, sizeof(path), "/dev/%s", dent->d_name) >= sizeof(path)) continue; +#ifdef USE_SULOGIN_EMERGENCY_MOUNT + if (emergency_flags & MNT_DEVTMPFS) + mknod(path, S_IFCHR|S_IRUSR|S_IWUSR, comparedev); +#endif + name = canonicalize_path(path); break; } |