Bug#570382: after upgrade: "vlogin: openpty(): No such file or directory"]

[Dan Gardner <dan@chaotica.org.uk>]

Unfortunately it seems my fix does not work. The problem is not
consistently reproducible, hence my belief I had fixed it.

I tried backporting the util-vserver package from squeeze
(0.30.216-pre2864-1) and had exactly the same problem.

The problem appears to be caused by failure of old_mmap() in
secure-mount. Here is the strace output of a failed secure-mount:

execve("/usr/lib/util-vserver/secure-mount",
["/usr/lib/util-vserver/secure-mou"..., "-a", "--chroot", "--fstab",
"/etc/vservers/XXX/fstab", "--rootfs", "no"], [/* 31 vars */]) = 0
open(".", O_RDONLY|O_LARGEFILE|O_DIRECTORY) = 3
open("/", O_RDONLY|O_LARGEFILE|O_DIRECTORY) = 4
fcntl64(3, F_SETFD, FD_CLOEXEC)         = 0
fcntl64(4, F_SETFD, FD_CLOEXEC)         = 0
rt_sigaction(SIGCHLD, {SIG_DFL}, {SIG_DFL}, 8) = 0
open("/etc/vservers/XXX/fstab", O_RDONLY|O_LARGEFILE) = 5
_llseek(5, 0, [393], SEEK_END)          = 0
_llseek(5, 0, [0], SEEK_SET)            = 0
read(5, "none\t/proc\t\tproc\tdefaults\t\t0 0\nno"..., 394) = 393
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS,
-1, 0xbffff28408086038) = 0x40001000
chdir("/")                              = 0
fchdir(3)                               = 0
chroot(".")                             = 0
chdir("/proc")                          = 0
open(".", O_RDONLY|O_LARGEFILE|O_DIRECTORY) = 6
fchdir(4)                               = 0
chroot(".")                             = 0
fchdir(6)                               = 0
close(6)                                = 0
mount("none", ".", "proc", MS_NODEV, "") = 0
fchdir(3)                               = 0
chroot(".")                             = 0
open("/etc/mtab", O_WRONLY|O_CREAT|O_APPEND|O_LARGEFILE, 0644) = 6
fcntl(6, F_SETLKW, {type=F_WRLCK, whence=SEEK_CUR, start=0, len=0}) = 0
write(6, "none"..., 4)                  = 4
write(6, " "..., 1)                     = 1
write(6, "/proc"..., 5)                 = 5
write(6, " "..., 1)                     = 1
write(6, "proc"..., 4)                  = 4
write(6, " "..., 1)                     = 1
write(6, "defaults"..., 8)              = 8
write(6, " 0 0\n"..., 5)                = 5
close(6)                                = 0
fchdir(4)                               = 0
chroot(".")                             = 0
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS,
-1, 0xbffff28408086038) = -1 ENOMEM (Cannot allocate memory)
--- SIGSEGV (Segmentation fault) @ 0 (0) ---
+++ killed by SIGSEGV +++

I have also tried using ulimit to turn off any potential limits which
might be causing this but without success.