[Plash] Firefox now hangs

[Thomas Leonard]

Hi all,

I've been running firefox under plash for a while, using this script
(on Debian/unstable):

#!/bin/sh
export FIREFOX_DSP=none
cp ~/.Xauthority ~/.firefox-jail/.Xauthority
ARGS=""
for x in $*; do
 ARGS="$ARGS -a $x"
done
exec pola-run --cwd / -B --prog /usr/bin/mozilla-firefox -f /etc --x11 \
        -fw /tmp \
        -f / \
        -f ~/public_html \
        -f ~/rox \
        -tw /home/talex ~/.firefox-jail $ARGS

This was working fine (plash-0.16), but I upgraded something and now
it just hangs on startup. stracing it shows:

10613 sendmsg(11, {msg_name(0)=NULL,
msg_iov(1)=[{"MSG!;\0\0\0\0\0\0\0Invk\0\0\0\0\1\0\0\0\2\0\0\0Call"...,
72}], msg_controllen=12, {cmsg_len=12, cmsg_level=SOL_SOCKET,
cmsg_type=SCM_RIGHTS, ...}, msg_flags=0}, MSG_NOSIGNAL) = 72
10613 recvmsg(11, {msg_name(0)=NULL,
msg_iov(1)=[{"MSG!D\0\0\0\0\0\0\0Invk\0\0\0\0\0\0\0\0RSta\3\3\0\0"...,
10144}], msg_controllen=0, msg_flags=0}, 0) = 80
10613 sendmsg(11, {msg_name(0)=NULL,
msg_iov(1)=[{"MSG!6\0\0\0\0\0\0\0Invk\0\0\0\0\1\0\0\0\2\0\0\0Call"...,
68}], msg_controllen=12, {cmsg_len=12, cmsg_level=SOL_SOCKET,
cmsg_type=SCM_RIGHTS, ...}, msg_flags=0}, MSG_NOSIGNAL) = 68
10613 recvmsg(11, {msg_name(0)=NULL,
msg_iov(1)=[{"MSG!\24\0\0\0\1\0\0\0Invk\0\0\0\0\1\0\0\0\1\3\0\0RDfd"...,
10240}], msg_controllen=16, {cmsg_len=16, cmsg_level=SOL_SOCKET,
cmsg_type=SCM_RIGHTS, {25}}, msg_flags=0}, 0) = 32
10613 fcntl64(25, F_SETFD, FD_CLOEXEC)  = 0
10613 sendmsg(11, {msg_name(0)=NULL,
msg_iov(1)=[{"MSG!\34\0\0\0\0\0\0\0Invk\0\0\0\0\2\0\0\0\2\0\0\0\0\3\0"...,
40}], msg_controllen=12, {cmsg_len=12, cmsg_level=SOL_SOCKET,
cmsg_type=SCM_RIGHTS, ...}, msg_flags=0}, MSG_NOSIGNAL) = 40
10613 recvmsg(11, {msg_name(0)=NULL,
msg_iov(1)=[{"MSG!D\0\0\0\0\0\0\0Invk\0\0\0\0\0\0\0\0Okay\3\3\0\0"...,
10208}], msg_controllen=0, msg_flags=0}, 0) = 80
10613 old_mmap(NULL, 4096, PROT_READ, MAP_PRIVATE, 25, 0) = -1 ENODEV
(No such device)
10613 read(25, "", 4096)                = 0
10613 read(25, "", 4096)                = 0
10613 read(25, "", 4096)                = 0
10613 read(25, "", 4096)                = 0
10613 read(25, "", 4096)                = 0

The reads just continue forever. Other programs still run OK with
plash. Looking in /proc/10613/fd, we have:

lr-x------ 1 1830190 1830190 64 May  4 20:26 25 -> /dev/null

Looking for debug options, I managed to get plash to say:

$ firefox
plash: warning: using open() on a directory, `/tmp/gconfd-talex', is
not fully supported
plash: warning: using open() on a directory, `/usr/share/fonts/type1',
is not fully supported

Looking at the Linux source, in do_mmap_pgoff() we have:

                if (!file->f_op || !file->f_op->mmap)
                        return -ENODEV;

Running firefox without plash works fine.

Any idea how to debug this?

Thanks,


--
Dr Thomas Leonard               http://rox.sourceforge.net
GPG: 9242 9807 C985 3C07 44A6  8B9A AE07 8280 59A5 3CC1