linux-toradex.git/fs/select.c, branch v2.6.34

Add generic sys_old_select()

2010-03-12T23:52:32+00:00

Add a generic implementation of the old select() syscall, which expects
its argument in a memory block and switch all architectures over to use
it.

Signed-off-by: Christoph Hellwig 
Cc: Ralf Baechle 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mundt 
Cc: Jeff Dike 
Cc: Hirokazu Takata 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Reviewed-by: H. Peter Anvin 
Cc: Al Viro 
Cc: Arnd Bergmann 
Cc: Heiko Carstens 
Cc: Martin Schwidefsky 
Cc: "Luck, Tony" 
Cc: James Morris 
Acked-by: Andreas Schwab 
Acked-by: Russell King 
Acked-by: Greg Ungerer 
Acked-by: David Howells 
Cc: Andreas Schwab 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs: use rlimit helpers

2010-03-06T19:26:29+00:00

Make sure compiler won't do weird things with limits.  E.g.  fetching them
twice may return 2 different values after writable limits are implemented.

I.e.  either use rlimit helpers added in commit 3e10e716abf3 ("resource:
add helpers for fetching rlimits") or ACCESS_ONCE if not applicable.

Signed-off-by: Jiri Slaby 
Cc: Alexander Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

headers: remove sched.h from poll.h

2009-10-04T22:05:10+00:00

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Linus Torvalds

poll/select: avoid arithmetic overflow in __estimate_accuracy()

2009-09-23T14:39:27+00:00

__estimate_accuracy() was prone to integer overflow, for example if *tv ==
{2147, 483648000} on a 32 bit computer (or even for delays as small as
{429, 500000000} if the task is niced).

Because the result was already forced between 0 and 100ms, the effect of
the overflow was not too problematic, but the use of the hrtimer range
feature was not optimal in overflow cases.

This patch ensures that there can not be an integer overflow in this
function.

Signed-off-by: Guillaume Knispel 
Cc: Alexander Viro 
Cc: Arjan van de Ven 
Cc: Thomas Gleixner 
Cc: Heiko Carstens 
Cc: Tejun Heo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

poll/select: initialize triggered field of struct poll_wqueues

2009-08-16T01:40:11+00:00

The triggered field of struct poll_wqueues introduced in commit
5f820f648c92a5ecc771a96b3c29aa6e90013bba ("poll: allow f_op->poll to
sleep").

It was first set to 1 in pollwake() (now __pollwake() ), tested and
later set to 0 in poll_schedule_timeout(), but not initialized before.

As a result when the process needs to sleep, triggered was likely to be
non-zero even if pollwake() is not called before the first
poll_schedule_timeout(), meaning schedule_hrtimeout_range() would not be
called and an extra loop calling all ->poll() would be done.

This patch initialize triggered to 0 in poll_initwait() so the ->poll()
are not called twice before the process goes to sleep when it needs to.

Signed-off-by: Guillaume Knispel 
Acked-by: Thomas Gleixner 
Acked-by: Tejun Heo 
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds

poll: avoid extra wakeups in select/poll

2009-06-17T02:47:48+00:00

After introduction of keyed wakeups Davide Libenzi did on epoll, we are
able to avoid spurious wakeups in poll()/select() code too.

For example, typical use of poll()/select() is to wait for incoming
network frames on many sockets.  But TX completion for UDP/TCP frames call
sock_wfree() which in turn schedules thread.

When scheduled, thread does a full scan of all polled fds and can sleep
again, because nothing is really available.  If number of fds is large,
this cause significant load.

This patch makes select()/poll() aware of keyed wakeups and useless
wakeups are avoided.  This reduces number of context switches by about 50%
on some setups, and work performed by sofirq handlers.

Signed-off-by: Eric Dumazet 
Acked-by: David S. Miller 
Acked-by: Andi Kleen 
Acked-by: Ingo Molnar 
Acked-by: Davide Libenzi 
Cc: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[CVE-2009-0029] System call wrappers part 32

2009-01-14T13:15:31+00:00

Signed-off-by: Heiko Carstens

[CVE-2009-0029] System call wrappers part 23

2009-01-14T13:15:28+00:00

Signed-off-by: Heiko Carstens

[CVE-2009-0029] Make sys_pselect7 static

2009-01-14T13:15:16+00:00

Not a single architecture has wired up sys_pselect7 plus it is the
only system call with seven parameters. Just make it static and
rename it to do_pselect which will do the work for sys_pselect6.

Signed-off-by: Heiko Carstens

Fix timeouts in sys_pselect7

2009-01-13T22:45:17+00:00

Since we (Analog Devices) updated our Blackfin kernel to 2.6.28, we've
seen occasional 5-second hangs from telnet.  telnetd calls select with a
NULL timeout, but with the new kernel, the system call occasionally
returns 0, which causes telnet to call sleep (5).  This did not happen
with earlier kernels.

The code in sys_pselect7 looks a bit strange, in particular the variable
"to" is initialized to NULL, then changed if a non-null timeout was
passed in, but not used further.  It needs to be passed to
core_sys_select instead of &end_time.

This bug was introduced by 8ff3e8e85fa6c312051134b3953e397feb639f51
("select: switch select() and poll() over to hrtimers").

Signed-off-by: Bernd Schmidt 
Reviewed-by: Ulrich Drepper 
Tested-by: Robin Getz 
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds