IFH@204581

MFC r198508, r198509:
Reimplement pselect() in kernel, making change of sigmask and sleep atomic.

MFC r198538:
Move pselect(3) man page to section 2.

MFC @199204

Current pselect(3) is implemented in usermode and thus vulnerable to
well-known race condition, which elimination was the reason for the
function appearance in first place. If sigmask supplied as arg

Current pselect(3) is implemented in usermode and thus vulnerable to
well-known race condition, which elimination was the reason for the
function appearance in first place. If sigmask supplied as argument to
pselect() enables a signal, the signal might be delivered before thread
called select(2), causing lost wakeup. Reimplement pselect() in kernel,
making change of sigmask and sleep atomic.

Since signal shall be delivered to the usermode, but sigmask restored,
set TDP_OLDMASK and save old mask in td_oldsigmask. The TDP_OLDMASK
should be cleared by ast() in case signal was not gelivered during
syscall execution.

Reviewed by: davidxu
Tested by: pho
MFC after: 1 month

show more ...

- MFC

Merge from head

Merge from head up to r188941 (last revision before the USB stack switch)

MFC r197049:
Calculate the amount of bytes to copy for select filedescriptor masks
taking into account size of fd_set for the current process ABI.

Approved by: re (kensmith)

kern_select(9) copies fd_set in and out of userspace in quantities of
longs. Since 32bit processes longs are 4 bytes, 64bit kernel may copy in
or out 4 bytes more then the process expected.

Calculat

kern_select(9) copies fd_set in and out of userspace in quantities of
longs. Since 32bit processes longs are 4 bytes, 64bit kernel may copy in
or out 4 bytes more then the process expected.

Calculate the amount of bytes to copy taking into account size of fd_set
for the current process ABI.

Diagnosed and tested by: Peter Jeremy <peterjeremy acm org>
Reviewed by: jhb
MFC after: 1 week

show more ...

- MFC from head@196987

MFC r196460

Fix the conformance of poll(2) for sockets after r195423 by
returning POLLHUP instead of POLLIN for several cases. Now, the
tools/regression/poll results for FreeBSD are closer to

MFC r196460

Fix the conformance of poll(2) for sockets after r195423 by
returning POLLHUP instead of POLLIN for several cases. Now, the
tools/regression/poll results for FreeBSD are closer to that of the
Solaris and Linux.

Also, improve the POSIX conformance by explicitely clearing POLLOUT
when POLLHUP is reported in pollscan(), making the fix global.

Submitted by: bde
Reviewed by: rwatson

MFC r196556

Fix poll() on half-closed sockets, while retaining POLLHUP for fifos.

This reverts part of r196460, so that sockets only return POLLHUP if both
directions are closed/error. Fifos get POLLHUP by closing the unused
direction immediately after creating the sockets.

The tools/regression/poll/*poll.c tests now pass except for two other
things:
- if POLLHUP is returned, POLLIN is always returned as well instead of
only when there is data left in the buffer to be read
- fifo old/new reader distinction does not work the way POSIX specs it

Reviewed by: kib, bde

MFC r196554

Add some tests for poll(2)/shutdown(2) interaction.

Approved by: re (kensmith)

show more ...

Fix the conformance of poll(2) for sockets after r195423 by
returning POLLHUP instead of POLLIN for several cases. Now, the
tools/regression/poll results for FreeBSD are closer to that of the
Solaris

Fix the conformance of poll(2) for sockets after r195423 by
returning POLLHUP instead of POLLIN for several cases. Now, the
tools/regression/poll results for FreeBSD are closer to that of the
Solaris and Linux.

Also, improve the POSIX conformance by explicitely clearing POLLOUT
when POLLHUP is reported in pollscan(), making the fix global.

Submitted by: bde
Reviewed by: rwatson
MFC after: 1 week

show more ...

- MFC

Audit file descriptor and command arguments to ioctl(2).

Approved by: re (audit argument blanket)
MFC after: 1 week

- Use fd_lastfile + 1 as the upper bound on nd. This is more correct than
using the size of the descriptor array.
- A lock is not needed to fetch fd_lastfile. The results are stale the
insta

- Use fd_lastfile + 1 as the upper bound on nd. This is more correct than
using the size of the descriptor array.
- A lock is not needed to fetch fd_lastfile. The results are stale the
instant it is dropped.
- Use a private mutex pool for select since the pool mutex is not used
as a leaf.
- Fetch the si_mtx pointer first before resorting to hashing to compute
the mutex address.

Reviewed by: McKusick
Approved by: re (kib)

show more ...

Replace AUDIT_ARG() with variable argument macros with a set more more
specific macros for each audit argument type. This makes it easier to
follow call-graphs, especially for automated analysis too

Replace AUDIT_ARG() with variable argument macros with a set more more
specific macros for each audit argument type. This makes it easier to
follow call-graphs, especially for automated analysis tools (such as
fxr).

In MFC, we should leave the existing AUDIT_ARG() macros as they may be
used by third-party kernel modules.

Suggested by: brooks
Approved by: re (kib)
Obtained from: TrustedBSD Project
MFC after: 1 week

show more ...

Merge from HEAD

- Implement a lockless file descriptor lookup algorithm in
fget_unlocked().
- Save old file descriptor tables created on expansion until
the entire descriptor table is freed so that pointers m

- Implement a lockless file descriptor lookup algorithm in
fget_unlocked().
- Save old file descriptor tables created on expansion until
the entire descriptor table is freed so that pointers may be
followed without regard for expanders.
- Mark the file zone as NOFREE so we may attempt to reference
potentially freed files.
- Convert several fget_locked() users to fget_unlocked(). This
requires us to manage reference counts explicitly but reduces
locking overhead in the common case.

show more ...

Update the projects tree to a newer FreeBSD current.

When writing out updated pollfd records when returning from
poll(), only copy out the revents field, not the whole pollfd
structure. Otherwise, if the events field is updated
concurrently by another

When writing out updated pollfd records when returning from
poll(), only copy out the revents field, not the whole pollfd
structure. Otherwise, if the events field is updated
concurrently by another thread, that update may be lost.

This issue apparently causes problems for the JDK on FreeBSD,
which expects the Linux behavior of not updating all fields
(somewhat oddly, Solaris does not implement the required
behavior, but presumably our adaptation of the JDK is based
on the Linux port?).

MFC after: 2 weeks
PR: kern/130924
Submitted by: Kurt Miller <kurt @ intricatesoftware.com>
Discussed with: kib

show more ...

Extract the no_poll() and vop_nopoll() code into the common routine
poll_no_poll().
Return a poll_no_poll() result from devfs_poll_f() when
filedescriptor does not reference the live cdev, instead of

Extract the no_poll() and vop_nopoll() code into the common routine
poll_no_poll().
Return a poll_no_poll() result from devfs_poll_f() when
filedescriptor does not reference the live cdev, instead of ENXIO.

Noted and tested by: hps
MFC after: 1 week

show more ...

Fix select on platforms where sizeof(long) != sizeof(int). This used
to work by accident before the cleanup done in revision 187693.

Approved by: kan (mentor)

- bit has to be fd_mask to work properly on 64bit platforms. Constants
must also be cast even though the result ultimately is promoted
to 64bit.
- Correct a loop index upper bound in selscan(

- bit has to be fd_mask to work properly on 64bit platforms. Constants
must also be cast even though the result ultimately is promoted
to 64bit.
- Correct a loop index upper bound in selscan().

show more ...

- Correct a typo in a comment.

Noticed by: danger

Fix errors introduced when I rewrote select.
- Restructure selscan() and selrescan() to avoid producing extra selfps
when we have a fd in multiple sets. As described below multiple selfps
may

Fix errors introduced when I rewrote select.
- Restructure selscan() and selrescan() to avoid producing extra selfps
when we have a fd in multiple sets. As described below multiple selfps
may still exist for other reasons.
- Make selrescan() tolerate multiple selfds for a given descriptor
set since sockets use two selinfos per fd. If an event on each selinfo
fires selrescan() will see the descriptor twice. This could result in
select() returning 2x the number of fds actually existing in fd sets.

Reported by: mgleason@ncftp.com

show more ...