With this patch any thread can dequeue its own private signals via signalfd,
even if it was created by another sub-thread.
To do so, we pass "current" to dequeue_signal() if the caller is from the same
thread group. This also fixes the scheduling of posix timers broken by the
previous patch.
If the caller doesn't belong to this thread group, we can't handle __SI_TIMER
case properly anyway. Perhaps we should forbid the cross-process signalfd usage
and convert ctx->tsk to ctx->sighand.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Roland McGrath <roland@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dequeue_signal:
if (__SI_TIMER) {
spin_unlock(&tsk->sighand->siglock);
do_schedule_next_timer(info);
spin_lock(&tsk->sighand->siglock);
}
Unless tsk == curent, this is absolutely unsafe: nothing prevents tsk from
exiting. If signalfd was passed to another process, do_schedule_next_timer()
is just wrong.
Add yet another "tsk == current" check into dequeue_signal().
This patch fixes an oopsable bug, but breaks the scheduling of posix timers
if the shared __SI_TIMER signal was fetched via signalfd attached to another
sub-thread. Mostly fixed by the next patch.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Roland McGrath <roland@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sys_timer_create() sets ->it_process and unlocks ->siglock, then checks
tmr->it_sigev_notify to define if get_task_struct() is needed.
We already passed ->it_id to the caller, another thread can delete this timer
and free its memory in between.
As a minimal fix, move this code under ->siglock, sys_timer_delete() takes it
too before calling release_posix_timer(). A proper serialization would be to
take ->it_lock, we add a partly initialized timer on posix_timers_id, not
good.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
timer_delete does:
lock_timer();
timer->it_process = NULL;
unlock_timer();
release_posix_timer();
timer->it_process is checked in lock_timer() to prevent access to a
timer, which is on the way to be deleted, but the check happens after
idr_lock is dropped. This allows release_posix_timer() to delete the
timer before the lock code can check the timer:
CPU 0 CPU 1
lock_timer();
timer->it_process = NULL;
unlock_timer();
lock_timer()
spin_lock(idr_lock);
timer = idr_find();
spin_lock(timer->lock);
spin_unlock(idr_lock);
release_posix_timer();
spin_lock(idr_lock);
idr_remove(timer);
spin_unlock(idr_lock);
free_timer(timer);
if (timer->......)
Change the locking to prevent this.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
m68k/mac: Make mac_hid_mouse_emulate_buttons() declaration visible
drivers/char/keyboard.c: In function 'kbd_keycode':
drivers/char/keyboard.c:1142: error: implicit declaration of function 'mac_hid_mouse_emulate_buttons'
The forward declaration of mac_hid_mouse_emulate_buttons() is not visible on
m68k because it's hidden in the middle of a big #ifdef block.
Move it to <linux/kbd_kern.h>, correct the type of the second parameter, and
include <linux/kbd_kern.h> where needed.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don't include RODATA into text segment as it includes the kallsyms data and
can cause spurious link failures (layout differences can change the number of
symbols in kallsyms, i.e. when a symbol is equal to _etext it's not
included).
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When suspend is ever implemented for pmu68k it really should follow the
generic pm_ops concept and not mirror the platform-specific /dev/pmu
device with ioctls on it. Hence, this patch removes the unused code there;
should the implementers need it they can look at via-pmu.c and/or the
history of the file.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The new exec code inserts an accounted vma into an mm struct which is not
current->mm. The existing memory check code has a hard coded assumption
that this does not happen as does the security code.
As the correct mm is known we pass the mm to the security method and the
helper function. A new security test is added for the case where we need
to pass the mm and the existing one is modified to pass current->mm to
avoid the need to change large amounts of code.
(Thanks to Tobias for fixing rejects and testing)
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: WU Fengguang <wfg@mail.ustc.edu.cn>
Cc: James Morris <jmorris@redhat.com>
Cc: Tobias Diedrich <ranma+kernel@tdiedrich.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The new rtc-m41t80 driver name doesn't match its module name, which
prevents it from properly hotplugging. Since it's new, no platforms yet
depend on that name ... so this patch fixes the driver name to match its
module name, rather than going the other way around with a MODULE_ALIAS().
NOTE: This sort of bug is a new thing to watch out for with new-style I2C
drivers; previously I2C couldn't hotplug.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lumpy reclaim works by selecting a lead page from the LRU list and then
selecting pages for reclaim from the order-aligned area of pages. In the
situation were all pages in that region are inactive and not referenced by any
process over time, it works well.
In the situation where there is even light load on the system, the pages may
not free quickly. Out of a area of 1024 pages, maybe only 950 of them are
freed when the allocation attempt occurs because lumpy reclaim returned early.
This patch alters the behaviour of direct reclaim for large contiguous
blocks.
The first attempt to call shrink_page_list() is asynchronous but if it fails,
the pages are submitted a second time and the calling process waits for the IO
to complete. This may stall allocators waiting for contiguous memory but that
should be expected behaviour for high-order users. It is preferable behaviour
to potentially queueing unnecessary areas for IO. Note that kswapd will not
stall in this fashion.
[apw@shadowen.org: update to version 2]
[apw@shadowen.org: update to version 3]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As pointed out by Mel when reclaim is applied at higher orders a significant
amount of IO may be started. As this takes finite time to drain reclaim will
consider more areas than ultimatly needed to satisfy the request. This leads
to more reclaim than strictly required and reduced success rates.
I was able to confirm Mel's test results on systems locally. These show that
even under light load the success rates drop off far more than expected.
Testing with a modified version of his patch (which follows) I was able to
allocate almost all of ZONE_MOVABLE with a near idle system. I ran 5 test
passes sequentially following system boot (the system has 29 hugepages in
ZONE_MOVABLE):
2.6.23-rc1 11 8 6 7 7
sync_lumpy 28 28 29 29 26
These show that although hugely better than the near 0% success normally
expected we can only allocate about a 1/4 of the zone. Using synchronous
reclaim for these allocations we get close to 100% as expected.
I have also run our standard high order tests and these show no regressions in
allocation success rates at rest, and some significant improvements under
load.
This patch:
We are transitioning pages from active to inactive in clear_active_flags,
those need counting as PGDEACTIVATE vm events.
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit b663a79c19 ("taskstats: add
context-switch counters") incorrectly removed a comma from a printf
statement. This causes corruption in the output printing or a seg
fault.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If we're going to run the handler from free_irq() then we must do it with
local irq's disabled. Otherwise lockdep complains that the handler is taking
irq-safe spinlocks in a non-irq-safe fashion.
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The serial_pci driver tries to guess serial ports on unknown devices based
on the PCI class (modem or serial). On certain softmodems (AC'97 modems)
this can lead to the recognition of non-existing serial ports.
This patch adds a blacklist of PCI IDs that are to be ignored by the driver.
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Christian Schmidt <schmidt@digadd.de>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Russell King <rmk+lkml@arm.linux.org.uk>
Cc: Yinghai Lu <yinghai.lu@sun.com>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reading the LSR clears the break, parity, frame error, and overrun bits in
the 8250 chip, but these are not being saved in all places that read the
LSR. Same goes for the MSR delta bits. Save the LSR bits off whenever the
lsr is read so they can be handled later in the receive routine. Save the
MSR bits to be handled in the modem status routine.
Also, clear the stored bits and clear the interrupt registers before
enabling interrupts, to avoid handling old values of the stored bits in the
interrupt routines.
[akpm@linux-foundation.org: clean up pre-existing code]
Signed-off-by: Corey Minyard <minyard@acm.org>
Cc: Russell King <rmk+lkml@arm.linux.org.uk>
Cc: Yinghai Lu <yinghai.lu@sun.com>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
