tree 5bd7f019aaf28184c765b94c563ceb9585cb3418
parent dbbf0045b6dba0df28761e37be03f3127d2d2dd9
author Pete Delaney <piet.delaney@imgtec.com> 1361419519 -0800
committer Pete Delaney <piet.delaney@imgtec.com> 1361419519 -0800

[MIPS] Added support for file descriptor related system calls.

Specifically these functions are now supported:
    signalfd4(), eventfd(), timerfd_create(),
    pipe(), and inotify_init1()

Modified syscall_portable() to call signalfd4_portable(),
eventfd_portable(), eventfd2_portable(), and timerfd_create().
These system calls enable the read system calls to access
kernel data structures.

The signalfd4() enables read to return a signalfd_siginfo structure
which have the signal number and errno mapped until an execve().
This is similar to the maintaining a table of signal handlers to
map the signal numbers done earlier. This mapping is extended to
the process after an execve() by passing the final set of mapped
file descriptors via a pair of environment variables.

Disabling signal and file descriptor read mapping in parent
if the child would break the mapping algorithms.

This code passes at least all of the non-POSIX LTP tests,
including an updated LTP signalfd4 test that posts SIGNALS
and uses this read() mechanism to get signal info.

inotify_init1 is similar to signalfd(), timerfd() and other
filefd functions which map read() calls. Unlike signalfd(), and
similar to timerfd(), the reads don't appear to need to be mapped.

The members of the inotify_event structure appear to be generic.
The mask bits like IN_MOVE_FROM and IN_MOVE_TO are defined in
generic files. The LTP test in testcases/kernel/syscalls/inotify
test for the inotify_event structure being inotify_event structure
being read and does seem to check it contents being correct.

Change-Id: I3f2dcd4e33437ac953cd9f67f56dccc6ec6e5e6f
Signed-off-by: Pete Delaney <piet.delaney@imgtec.com>
Signed-off-by: Chris Dearman <chris.dearman@imgtec.com>
Signed-off-by: Paul Lind <paul.lind@imgtec.com>