Bug 975541

This is something really strange and I have no clue if it is bug or some
esoteric feature, but one would not expect su/sudo-like program killing
its slave after some timeout is reached.

Look (full strace will follow):

$ strace -f -tt gksu-polkit pango-view /etc/sudoers
18:58:55.326702
  execve("/bin/gksu-polkit", ["gksu-polkit", "pango-view", "/etc/sudoers"],
         [/* 53 vars */]) = 0
18:58:55.327415
  brk(0)                  = 0x163e000
18:58:55.327551
  mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
  = 0x7f7651afa000
18:58:55.327696
  access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
18:58:55.327841
  open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[...]
18:58:55.532148 socket(PF_FILE, SOCK_STREAM|SOCK_CLOEXEC, 0) = 5
18:58:55.532338 connect(5, {sa_family=AF_FILE,
                        sun_path="/var/run/dbus/system_bus_socket"}, 33) = 0
[...]
18:59:00.191351 write(4, "\1\0\0\0\0\0\0\0", 8) = 8
18:59:00.191378 fstat(10, {st_mode=S_IFIFO|0600, st_size=0, ...}) = 0
18:59:00.191403 fcntl(10, F_GETFL)      = 0x800 (flags O_RDONLY|O_NONBLOCK)
18:59:00.191428 write(4, "\1\0\0\0\0\0\0\0", 8) = 8
18:59:00.191465 poll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN},
                      {fd=5, events=POLLIN}, {fd=6, events=POLLIN|POLLPRI},
                      {fd=7, events=0}, {fd=8, events=0}, {fd=9, events=0},
                      {fd=10, events=0}, {fd=11, events=0}, {fd=7, events=0},
                      {fd=0, events=POLLIN|POLLPRI},
                      {fd=8, events=POLLIN|POLLPRI},
                      {fd=10, events=POLLIN|POLLPRI}], 13, 0) = 2
                     ([{fd=4, revents=POLLIN}, {fd=3, revents=POLLIN}])
18:59:00.191564 recvfrom(3, "\21\0\205\0\4\0@\3\4\0@\3\0\0\0\0\0\0\0\0\0\0\0
                             \0\0\0\0\0\0\0\0\0", 4096, 0, NULL, NULL) = 32
18:59:00.191601 recvfrom(3, 0x16644f4, 4096, 0, 0, 0) = -1 EAGAIN
                         (Resource temporarily unavailable)
18:59:00.191631 recvfrom(3, 0x16644f4, 4096, 0, 0, 0) = -1 EAGAIN
                         (Resource temporarily unavailable)
18:59:00.191669 recvfrom(3, 0x16644f4, 4096, 0, 0, 0) = -1 EAGAIN
                         (Resource temporarily unavailable)
18:59:00.191713 poll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN},
                      {fd=5, events=POLLIN}, {fd=6, events=POLLIN|POLLPRI},
                      {fd=7, events=0}, {fd=8, events=0}, {fd=9, events=0},
                      {fd=10, events=0}, {fd=11, events=0}, {fd=7, events=0},
                      {fd=0, events=POLLIN|POLLPRI},
                      {fd=8, events=POLLIN|POLLPRI},
                      {fd=10, events=POLLIN|POLLPRI}], 13, 0) = 1
                      ([{fd=4, revents=POLLIN}])
18:59:00.191765 read(4, "\20\0\0\0\0\0\0\0", 16) = 8
18:59:00.191817 recvfrom(3, 0x16644f4, 4096, 0, 0, 0) = -1 EAGAIN
                         (Resource temporarily unavailable)
18:59:00.191847 poll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN},
                      {fd=5, events=POLLIN}, {fd=6, events=POLLIN|POLLPRI},
                      {fd=7, events=0}, {fd=8, events=0}, {fd=9, events=0},
                      {fd=10, events=0}, {fd=11, events=0}, {fd=7, events=0},
                      {fd=0, events=POLLIN|POLLPRI},
                      {fd=8, events=POLLIN|POLLPRI},
                      {fd=10, events=POLLIN|POLLPRI}], 13, 0) = 0 (Timeout)
18:59:00.191893 read(4, 0x7ffff8f51470, 16) = -1 EAGAIN
                      (Resource temporarily unavailable)
18:59:00.191937 recvfrom(3, 0x16644f4, 4096, 0, 0, 0) = -1 EAGAIN
                         (Resource temporarily unavailable)
18:59:00.191968 poll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN},
                      {fd=5, events=POLLIN}, {fd=6, events=POLLIN|POLLPRI},
                      {fd=7, events=0}, {fd=8, events=0}, {fd=9, events=0},
                      {fd=10, events=0}, {fd=11, events=0}, {fd=7, events=0},
                      {fd=0, events=POLLIN|POLLPRI},
                      {fd=8, events=POLLIN|POLLPRI},
                      {fd=10, events=POLLIN|POLLPRI}], 13, 4294967295)
                      = ? ERESTART_RESTARTBLOCK (Interrupted by signal)
18:59:06.690148 --- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
18:59:06.690180 restart_syscall(<... resuming interrupted call ...>) = 1
<note:
 empty gap that is finished by pango-view being disappeared/killed?
 at the same moment subsequent lines being printed
>
19:00:25.642729 write(4, "\1\0\0\0\0\0\0\0", 8) = 8
19:00:25.642834 recvmsg(5, {msg_name(0)=NULL, msg_iov(1)=[{"l\4\1\1%\0\0\0\5
                        \0\0\0\211\0\0\0\1\1o\0\25\0\0\0/org/fre"..., 2048}],
                        msg_controllen=0, msg_flags=MSG_CMSG_CLOEXEC},
                        MSG_CMSG_CLOEXEC) = 197
19:00:25.642886 write(4, "\1\0\0\0\0\0\0\0", 8) = 8
19:00:25.642917 recvmsg(5, 0x7ffff8f512d0, MSG_CMSG_CLOEXEC) = -1 EAGAIN
                        (Resource temporarily unavailable)
19:00:25.642948 write(4, "\1\0\0\0\0\0\0\0", 8) = 8
19:00:25.642977 recvfrom(3, 0x16644f4, 4096, 0, 0, 0) = -1 EAGAIN
                         (Resource temporarily unavailable)
19:00:25.643013 poll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN},
                      {fd=6, events=POLLIN|POLLPRI}, {fd=7, events=0},
                      {fd=8, events=0}, {fd=9, events=0}, {fd=10, events=0},
                      {fd=11, events=0}, {fd=7, events=0},
                      {fd=0, events=POLLIN|POLLPRI},
                      {fd=8, events=POLLIN|POLLPRI},
                      {fd=10, events=POLLIN|POLLPRI}, {fd=5, events=POLLIN}],
                      13, 0) = 1 ([{fd=4, revents=POLLIN}])
19:00:25.643093 recvfrom(3, 0x16644f4, 4096, 0, 0, 0) = -1 EAGAIN
                         (Resource temporarily unavailable)
19:00:25.643120 poll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN},
                      {fd=6, events=POLLIN|POLLPRI}, {fd=7, events=0},
                      {fd=8, events=0}, {fd=9, events=0}, {fd=10, events=0},
                      {fd=11, events=0}, {fd=7, events=0},
                      {fd=0, events=POLLIN|POLLPRI},
                      {fd=8, events=POLLIN|POLLPRI},
                      {fd=10, events=POLLIN|POLLPRI}, {fd=5, events=POLLIN}],
                      13, 4294967295) = 1 ([{fd=4, revents=POLLIN}])
19:00:25.643168 read(4, "\3\0\0\0\0\0\0\0", 16) = 8
19:00:25.643194 recvfrom(3, 0x16644f4, 4096, 0, 0, 0) = -1 EAGAIN
                         (Resource temporarily unavailable)
19:00:25.643217 poll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN},
                      {fd=6, events=POLLIN|POLLPRI}, {fd=7, events=0},
                      {fd=8, events=0}, {fd=9, events=0}, {fd=10, events=0},
                      {fd=11, events=0}, {fd=7, events=0},
                      {fd=0, events=POLLIN|POLLPRI},
                      {fd=8, events=POLLIN|POLLPRI},
                      {fd=10, events=POLLIN|POLLPRI}, {fd=5, events=POLLIN}],
                      13, 4294967295) = ? ERESTART_RESTARTBLOCK
                      (Interrupted by signal)
19:00:55.764739 --- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
19:00:55.764769 restart_syscall(<... resuming interrupted call ...>
<note:
 now, I've suspended the gksu-polkit process via ^Z, just to be able to
 kill it as a next step, as nothing meaningful can be done here
>

Apparently, this prevents gksu-polkit to be helpful at all (modulo one-off
commands).  Or maybe I am just missing its mission.

First I noted this in connection to running "enabled" wireshark:
[bug 959543].