Anton Vorontsov [Mon, 28 Apr 2008 09:14:47 +0000 (02:14 -0700)]
gpiochip_reserve()
Add a new function gpiochip_reserve() to reserve ranges of gpios that platform
code has pre-allocated. That is, this marks gpio numbers which will be
claimed by drivers that haven't yet been loaded, and thus are not available
for dynamic gpio number allocation.
[akpm@linux-foundation.org: remove unneeded __must_check]
[david-b@pacbell.net: don't export gpiochip_reserve (section fix)] Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Anton Vorontsov [Mon, 28 Apr 2008 09:14:46 +0000 (02:14 -0700)]
gpiolib: dynamic gpio number allocation
If gpio_chip->base is negative during registration, gpiolib performs dynamic
base allocation. This is useful for devices that aren't always present, such
as GPIOs on hotplugged devices rather than mainboards. (This behavior was
previously specified but not implemented.)
To avoid using any numbers that may have been explicitly assigned but not yet
registered, this dynamic allocation assigns GPIO numbers from the biggest
number on down, instead of from the smallest on up.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce a gpio_is_valid() predicate; use it in gpiolib.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
[ use inline function; follow the gpio_* naming convention;
work without gpiolib; all programming interfaces need docs ] Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the newly introduced owner field in struct gpio_chip to protect the
current (small) set of non-SOC GPIO drivers from being unloaded while any of
their GPIOs are in use.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
[ add mcp23s08 and pcf857x ] Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As long as one or more GPIOs on a gpio chip are used its driver should not be
unloaded. The existing mechanism (gpiochip_remove failure) doesn't address
that, since rmmod can no longer be made to fail by having the cleanup code
report errors. Module usecounts are the solution.
Assuming standard "initialize struct to zero" policies, this change won't
affect SOC platform drivers. However, drivers for external chips (on I2C and
SPI busses) should be updated if they can be built as modules.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
[ gpio_ensure_requested() needs to update module usecounts too ] Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Robert P. J. Day [Mon, 28 Apr 2008 09:14:42 +0000 (02:14 -0700)]
isdn: rename CONFIG_AVMB1_COMPAT to not look like a Kconfig variable
Since CONFIG_AVMB1_COMPAT is not a Kconfig variable, move it out of the
Kconfig namespace.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Acked-by: Karsten Keil <kkeil@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Robert P. J. Day [Mon, 28 Apr 2008 09:14:40 +0000 (02:14 -0700)]
isdn: fix obvious cut-and-paste error in st5481_usb.c
Fix a rather obvious cut-and-paste error, where earlier code for the
controller URB got somehow mixed in with code for the interrupt URB.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Cc: Karsten Keil <kkeil@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Harvey Harrison [Mon, 28 Apr 2008 09:14:39 +0000 (02:14 -0700)]
eicon: fix sparse integer as NULL pointer warnings
drivers/isdn/hardware/eicon/message.c:745:47: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/eicon/message.c:761:45: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/eicon/message.c:9122:16: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/eicon/message.c:9147:16: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/eicon/message.c:9173:14: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/eicon/divasmain.c:396:23: warning: Using plain integer as NULL pointer
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Cc: Karsten Keil <kkeil@suse.de> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Harvey Harrison [Mon, 28 Apr 2008 09:14:38 +0000 (02:14 -0700)]
avm: fix sparse warning using integer as NULL pointer
drivers/isdn/hardware/avm/b1isa.c:206:37: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/b1isa.c:208:33: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/b1.c:664:42: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/b1.c:666:44: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/b1.c:668:42: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/b1.c:791:37: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/b1.c:793:33: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/b1pci.c:385:37: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/b1pci.c:387:33: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/b1dma.c:886:42: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/b1dma.c:888:44: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/b1dma.c:890:42: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/b1dma.c:973:37: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/b1dma.c:975:33: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/b1pcmcia.c:204:37: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/b1pcmcia.c:206:33: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/t1isa.c:554:37: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/t1isa.c:556:33: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/t1pci.c:236:37: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/t1pci.c:238:33: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/c4.c:1091:42: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/c4.c:1093:44: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/c4.c:1095:42: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/c4.c:1170:21: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/c4.c:1294:37: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/avm/c4.c:1296:33: warning: Using plain integer as NULL pointer
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Cc: Karsten Keil <kkeil@suse.de> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Harvey Harrison [Mon, 28 Apr 2008 09:14:37 +0000 (02:14 -0700)]
capi: fix sparse warnings using integer as NULL pointer
drivers/isdn/capi/kcapi.c:829:30: warning: Using plain integer as NULL pointer
drivers/isdn/capi/kcapi.c:838:27: warning: Using plain integer as NULL pointer
drivers/isdn/capi/kcapi.c:954:17: warning: Using plain integer as NULL pointer
drivers/isdn/capi/kcapi.c:1007:37: warning: Using plain integer as NULL pointer
drivers/isdn/capi/kcapi.c:1009:33: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capiutil.c:453:24: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capilib.c:47:30: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capi.c:353:29: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capi.c:369:15: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capi.c:486:48: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capi.c:515:46: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capi.c:541:47: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capi.c:692:47: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capi.c:699:49: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capi.c:704:14: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capi.c:943:53: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capi.c:948:32: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capi.c:969:42: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capi.c:989:48: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capi.c:1026:69: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capi.c:1028:19: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capi.c:1061:20: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capi.c:1529:37: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capi.c:1531:33: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:338:15: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:758:32: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:880:40: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:407:15: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:429:49: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:407:15: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:444:49: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:429:49: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:429:49: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:429:49: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:429:49: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:429:49: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:1664:61: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:1969:37: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:2294:37: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:2297:33: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:2338:37: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capidrv.c:2341:33: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capifs.c:192:37: warning: Using plain integer as NULL pointer
drivers/isdn/capi/capifs.c:194:33: warning: Using plain integer as NULL pointer
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Cc: Karsten Keil <kkeil@suse.de> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrew Morton [Mon, 28 Apr 2008 09:14:35 +0000 (02:14 -0700)]
quota: convert stub functions from macros into inlines
Fixes things like this:
fs/super.c: In function `deactivate_super':
fs/super.c:182: warning: statement with no effect
fs/super.c: In function `do_remount_sb':
fs/super.c:644: warning: statement with no effect
Cc: Jan Kara <jack@ucw.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Mon, 28 Apr 2008 09:14:35 +0000 (02:14 -0700)]
quota: reiserfs: make reiserfs handle quotaon on remount
Update reiserfs to handle quotaon on remount RW.
Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Mon, 28 Apr 2008 09:14:34 +0000 (02:14 -0700)]
quota: ext4: make ext4 handle quotaon on remount
Update ext4 to handle quotaon on remount RW.
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Mon, 28 Apr 2008 09:14:34 +0000 (02:14 -0700)]
quota: ext3: make ext3 handle quotaon on remount
Update ext3 handle quotaon on remount RW.
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Mon, 28 Apr 2008 09:14:33 +0000 (02:14 -0700)]
quota: quota core changes for quotaon on remount
Currently, we just turn quotas off on remount of filesystem to read-only
state. The patch below adds necessary framework so that we can turn quotas
off on remount RO but we are able to automatically reenable them again when
filesystem is remounted to RW state. All we need to do is to keep references
to inodes of quota files when remounting RO and using these references to
reenable quotas when remounting RW.
Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Mon, 28 Apr 2008 09:14:32 +0000 (02:14 -0700)]
quota: various style cleanups
Cleanups in quota code:
Change __inline__ to inline.
Change some macros to inline functions.
Remove vfs_quota_off_mount() macro.
DQUOT_OFF() should be (0) is CONFIG_QUOTA is disabled.
Move declaration of mark_dquot_dirty and dirty_dquot from quota.h to dquot.c
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Mon, 28 Apr 2008 09:14:32 +0000 (02:14 -0700)]
quota: remove superfluous DQUOT_OFF() in fs/namespace.c
We don't need to turn quotas off before remounting root ro, because
do_remount_sb() already handles this.
Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
quota: do not allow setting of quota limits to too high values
We should check whether quota limits set via Q_SETQUOTA are not exceeding
limits which quota format is able to handle.
Signed-off-by: Andrew Perepechko <andrew.perepechko@sun.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kprobes: add (un)register_kprobes for batch registration
Introduce unregister_/register_kprobes() for kprobe batch registration. This
can reduce waiting time for synchronized_sched() when a lot of probes have to
be unregistered at once.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Shaohua Li <shaohua.li@intel.com> Cc: David Miller <davem@davemloft.net> Cc: "Frank Ch. Eigler" <fche@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Prohibit users from probing preempt_schedule(). One way of prohibiting the
user from probing functions is by marking such functions with __kprobes. But
this method doesn't work for those functions, which are already marked to
different section like preempt_schedule() (belongs to __sched section). So we
use blacklist approach to refuse user from probing these functions.
In blacklist approach we populate the blacklisted function's starting address
and its size in kprobe_blacklist structure. Then we verify the user specified
address against start and end of the blacklisted function. So any attempt to
register probe on blacklisted functions will be rejected.
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com> Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Jim Keniston <jkenisto@us.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Robert P. J. Day [Mon, 28 Apr 2008 09:14:24 +0000 (02:14 -0700)]
mfd: use shorter set_current_state()
Since this routine declares a separate "tsk" pointer for no other reason than
to call set_task_state(), get rid of it and just invoke set_current_state().
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Dmitry Torokhov <dtor@mail.ru> Cc: Nicolas Pitre <nico@cam.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Magnus Damm [Mon, 28 Apr 2008 09:14:22 +0000 (02:14 -0700)]
sm501: add uart support
This patch extends the sm501 mfd with 8250 uart support. We're currently
doing this in the board specific r2d-1 code already, but it would be nice to
do move things into the mfd since it's more chip specific than board specific.
Signed-off-by: Magnus Damm <damm@igel.co.jp> Cc: Ben Dooks <ben-linux@fluff.org> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2) End of transfers is now managed on TXFIFO empty interrupt after the
last write to TXFIFO. This speeds interrupt execution by removing
the wait for TXFIFO to become empty. On TXFIFO empty interrupt the
handler needs only to poll for the end of the ongoing transaction
(SPI_CONTROL_XCH) to close the transfer.
(2.1) Write only transfers are closed flushing RXFIFO.
(2.2) Read transfers are closed reading trailing bytes from RXFIFO.
(2.3) Read transfers where RXFIFO overrun occurred are closed by
flushing RXFIFO and aborting the message.
3) Fifos are now flushed via SPI disable after the end of ongoing
transaction.
Signed-off-by: Andrea Paterniani <a.paterniani@swapp-eng.it> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A spi transfer with zero length is not invalid. For example, such
transfer (len == 0 && delay_usecs != 0) can be used to achieve delay
before first CLK edge after chipselect assertion.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Brownell [Mon, 28 Apr 2008 09:14:17 +0000 (02:14 -0700)]
spi: pxa2xx_spi "sparse" fixes
Various cleanups to pxa2xx_spi suggested by "sparse": make sure that
register addresess are "void __iomem *", and make a few functions properly
static.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Ned Forrester <nforrester@whoi.edu> Cc: Stephen Street <stephen@streetfiresound.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Thomas Petazzoni [Mon, 28 Apr 2008 09:14:14 +0000 (02:14 -0700)]
x86: configurable DMI scanning code
Turn CONFIG_DMI into a selectable option if EMBEDDED is defined, in
order to be able to remove the DMI table scanning code if it's not
needed, and then reduce the kernel code size.
With CONFIG_DMI (i.e before) :
text data bss dec hex filename 1076076 128656 98304 1303036 13e1fc vmlinux
Without CONFIG_DMI (i.e after) :
text data bss dec hex filename 1068092 126308 98304 1292704 13b9a0 vmlinux
Result:
text data bss dec hex filename
-7984 -2348 0 -10332 -285c vmlinux
The new option appears in "Processor type and features", only when
CONFIG_EMBEDDED is defined.
This patch is part of the Linux Tiny project, and is based on previous work
done by Matt Mackall <mpm@selenic.com>.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Anvin" <hpa@zytor.com> Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrew Morton [Mon, 28 Apr 2008 09:14:13 +0000 (02:14 -0700)]
drivers/acpi/thermal.c: fix build with CONFIG_DMI=n
drivers/acpi/thermal.c: In function 'acpi_thermal_init':
drivers/acpi/thermal.c:1794: error: 'thermal_dmi_table' undeclared (first use in this function)
drivers/acpi/thermal.c:1794: error: (Each undeclared identifier is reported only once
drivers/acpi/thermal.c:1794: error: for each function it appears in.)
Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After commit 39d4c922b596633da86878b1a5cc881785b8e5fa (atmel_serial: fix
uart/console concurrent access) the UART_GET_TCR macro got redefined. This
patch removes the duplicated definition.
Signed-off-by: michael trimarchi <trimarchimichael@evidence.eu.com> Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Alex Williamson [Mon, 28 Apr 2008 09:14:09 +0000 (02:14 -0700)]
serial 8250: tighten test for using backup timer
Thomas Koeller had reported an issue where a device that had been making use
of the UART_BUG_TXEN code in the 8250 driver was mistakenly being caught by
the backup timer test, causing the device to work improperly.
To fix this, tighten the test requirements to enable the backup timer
workaround.
The backup timer is really meant to catch UARTs that don't re-assert the THRE
interrupt. The expectation is that they do initially assert THRE. This patch
clarifies the test.
Signed-off-by: Alex Williamson <alex.williamson@hp.com> Cc: Thomas Koeller <thomas@koeller.dyndns.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: 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>
Alan Cox [Mon, 28 Apr 2008 09:14:07 +0000 (02:14 -0700)]
uart_get_baud_rate: stop mangling termios
Russell King noticed this one: We have to avoid replacing B0 when we pick a
baud rate for a "hung up" port. Ugly but the proper fix is in the tty layer
and means changing the tty<->serial interfaces so we will defer that for now.
[akpm@linux-foundation.org: fix uninitialised var] Signed-off-by: Alan Cox <alan@redhat.com> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Alan Cox [Mon, 28 Apr 2008 09:14:06 +0000 (02:14 -0700)]
Fix tty speed handling on 8250
We try and write the correct speed back but the serial midlayer already
mangles the speed on us and that means if we request B0 we report back B9600
when we should not. For now we'll hack around this in the drivers and serial
code, pending a better long term solution.
Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Harvey Harrison [Mon, 28 Apr 2008 09:14:05 +0000 (02:14 -0700)]
char: make functions static in synclinkmp.c
All were forward declared with static.
Fixes sparse warnings:
drivers/char/synclinkmp.c:1476:5: warning: symbol 'read_proc' was not declared. Should it be static?
drivers/char/synclinkmp.c:2027:5: warning: symbol 'bh_action' was not declared. Should it be static?
drivers/char/synclinkmp.c:2058:6: warning: symbol 'bh_handler' was not declared. Should it be static?
drivers/char/synclinkmp.c:2103:6: warning: symbol 'bh_receive' was not declared. Should it be static?
drivers/char/synclinkmp.c:2112:6: warning: symbol 'bh_transmit' was not declared. Should it be static?
drivers/char/synclinkmp.c:2124:6: warning: symbol 'bh_status' was not declared. Should it be static?
drivers/char/synclinkmp.c:2136:6: warning: symbol 'isr_timer' was not declared. Should it be static?
drivers/char/synclinkmp.c:2162:6: warning: symbol 'isr_rxint' was not declared. Should it be static?
drivers/char/synclinkmp.c:2221:6: warning: symbol 'isr_rxrdy' was not declared. Should it be static?
drivers/char/synclinkmp.c:2351:6: warning: symbol 'isr_txint' was not declared. Should it be static?
drivers/char/synclinkmp.c:2379:6: warning: symbol 'isr_txrdy' was not declared. Should it be static?
drivers/char/synclinkmp.c:2410:6: warning: symbol 'isr_rxdmaok' was not declared. Should it be static?
drivers/char/synclinkmp.c:2427:6: warning: symbol 'isr_rxdmaerror' was not declared. Should it be static?
drivers/char/synclinkmp.c:2445:6: warning: symbol 'isr_txdmaok' was not declared. Should it be static?
drivers/char/synclinkmp.c:2463:6: warning: symbol 'isr_txdmaerror' was not declared. Should it be static?
drivers/char/synclinkmp.c:2480:6: warning: symbol 'isr_io_pin' was not declared. Should it be static?
drivers/char/synclinkmp.c:3420:5: warning: symbol 'alloc_dma_bufs' was not declared. Should it be static?
drivers/char/synclinkmp.c:3494:5: warning: symbol 'alloc_buf_list' was not declared. Should it be static?
drivers/char/synclinkmp.c:3553:5: warning: symbol 'alloc_frame_bufs' was not declared. Should it be static?
drivers/char/synclinkmp.c:3570:6: warning: symbol 'free_dma_bufs' was not declared. Should it be static?
drivers/char/synclinkmp.c:3580:5: warning: symbol 'alloc_tmp_rx_buf' was not declared. Should it be static?
drivers/char/synclinkmp.c:3588:6: warning: symbol 'free_tmp_rx_buf' was not declared. Should it be static?
drivers/char/synclinkmp.c:3594:5: warning: symbol 'claim_resources' was not declared. Should it be static?
drivers/char/synclinkmp.c:3681:6: warning: symbol 'release_resources' was not declared. Should it be static?
drivers/char/synclinkmp.c:3737:6: warning: symbol 'add_device' was not declared. Should it be static?
drivers/char/synclinkmp.c:3860:6: warning: symbol 'device_init' was not declared. Should it be static?
drivers/char/synclinkmp.c:4054:6: warning: symbol 'enable_loopback' was not declared. Should it be static?
drivers/char/synclinkmp.c:4101:6: warning: symbol 'set_rate' was not declared. Should it be static?
drivers/char/synclinkmp.c:4147:6: warning: symbol 'rx_stop' was not declared. Should it be static?
drivers/char/synclinkmp.c:4168:6: warning: symbol 'rx_start' was not declared. Should it be static?
drivers/char/synclinkmp.c:4225:6: warning: symbol 'tx_start' was not declared. Should it be static?
drivers/char/synclinkmp.c:4295:6: warning: symbol 'tx_stop' was not declared. Should it be static?
drivers/char/synclinkmp.c:4322:6: warning: symbol 'tx_load_fifo' was not declared. Should it be static?
drivers/char/synclinkmp.c:4371:6: warning: symbol 'reset_port' was not declared. Should it be static?
drivers/char/synclinkmp.c:4395:6: warning: symbol 'reset_adapter' was not declared. Should it be static?
drivers/char/synclinkmp.c:4407:6: warning: symbol 'async_mode' was not declared. Should it be static?
drivers/char/synclinkmp.c:4546:6: warning: symbol 'hdlc_mode' was not declared. Should it be static?
drivers/char/synclinkmp.c:4748:6: warning: symbol 'tx_set_idle' was not declared. Should it be static?
drivers/char/synclinkmp.c:4768:6: warning: symbol 'get_signals' was not declared. Should it be static?
drivers/char/synclinkmp.c:4797:6: warning: symbol 'set_signals' was not declared. Should it be static?
drivers/char/synclinkmp.c:4826:6: warning: symbol 'rx_reset_buffers' was not declared. Should it be static?
drivers/char/synclinkmp.c:4837:6: warning: symbol 'rx_free_frame_buffers' was not declared. Should it be static?
drivers/char/synclinkmp.c:4865:5: warning: symbol 'rx_get_frame' was not declared. Should it be static?
drivers/char/synclinkmp.c:5040:6: warning: symbol 'tx_load_dma_buffer' was not declared. Should it be static?
drivers/char/synclinkmp.c:5080:5: warning: symbol 'register_test' was not declared. Should it be static?
drivers/char/synclinkmp.c:5119:5: warning: symbol 'irq_test' was not declared. Should it be static?
drivers/char/synclinkmp.c:5211:5: warning: symbol 'init_adapter' was not declared. Should it be static?
drivers/char/synclinkmp.c:5270:5: warning: symbol 'loopback_test' was not declared. Should it be static?
drivers/char/synclinkmp.c:5335:5: warning: symbol 'adapter_test' was not declared. Should it be static?
drivers/char/synclinkmp.c:5397:5: warning: symbol 'memory_test' was not declared. Should it be static?
drivers/char/synclinkmp.c:5449:6: warning: symbol 'load_pci_memory' was not declared. Should it be static?
drivers/char/synclinkmp.c:5468:6: warning: symbol 'trace_block' was not declared. Should it be static?
drivers/char/synclinkmp.c:5503:6: warning: symbol 'tx_timeout' was not declared. Should it be static?
drivers/char/synclinkmp.c:5530:6: warning: symbol 'status_timeout' was not declared. Should it be static?
drivers/char/synclinkmp.c:5581:15: warning: symbol 'read_reg' was not declared. Should it be static?
drivers/char/synclinkmp.c:5586:6: warning: symbol 'write_reg' was not declared. Should it be static?
drivers/char/synclinkmp.c:5592:5: warning: symbol 'read_reg16' was not declared. Should it be static?
drivers/char/synclinkmp.c:5598:6: warning: symbol 'write_reg16' was not declared. Should it be static?
drivers/char/synclinkmp.c:5604:15: warning: symbol 'read_status_reg' was not declared. Should it be static?
drivers/char/synclinkmp.c:5610:6: warning: symbol 'write_control_reg' was not declared. Should it be static?
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Cc: Paul Fulghum <paulkf@microgate.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sam Ravnborg [Mon, 28 Apr 2008 09:14:02 +0000 (02:14 -0700)]
serial: silence section mismatch warnings in 8250_pci
Fix following warnings:
WARNING: drivers/serial/built-in.o(.data+0x5b8): Section mismatch in reference from the variable pci_serial_quirks to the function .devexit.text:pci_ite887x_exit()
WARNING: drivers/serial/built-in.o(.data+0x5e0): Section mismatch in reference from the variable pci_serial_quirks to the function .devexit.text:pci_plx9050_exit()
WARNING: drivers/serial/built-in.o(.data+0x608): Section mismatch in reference from the variable pci_serial_quirks to the function .devexit.text:pci_plx9050_exit()
WARNING: drivers/serial/built-in.o(.data+0x658): Section mismatch in reference from the variable pci_serial_quirks to the function .devexit.text:pci_plx9050_exit()
WARNING: drivers/serial/built-in.o(.data+0x680): Section mismatch in reference from the variable pci_serial_quirks to the function .devexit.text:pci_plx9050_exit()
WARNING: drivers/serial/built-in.o(.data+0x6a8): Section mismatch in reference from the variable pci_serial_quirks to the function .devexit.text:pci_plx9050_exit()
WARNING: drivers/serial/built-in.o(.data+0x6d0): Section mismatch in reference from the variable pci_serial_quirks to the function .devexit.text:sbs_exit()
WARNING: drivers/serial/built-in.o(.data+0x6f8): Section mismatch in reference from the variable pci_serial_quirks to the function .devexit.text:sbs_exit()
WARNING: drivers/serial/built-in.o(.data+0x720): Section mismatch in reference from the variable pci_serial_quirks to the function .devexit.text:sbs_exit()
WARNING: drivers/serial/built-in.o(.data+0x748): Section mismatch in reference from the variable pci_serial_quirks to the function .devexit.text:sbs_exit()
pci_serial_quirks contains a number of function pointers where the referenced
function is annotated __devexit. This is OK so we annotate pci_serial_quirks
with __refdata to ignore the __devexit references
Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Harvey Harrison [Mon, 28 Apr 2008 09:14:01 +0000 (02:14 -0700)]
ncpfs: fix sparse warning in ncpsign_kernel.c
We're casting anyway, might as well cast to the correct sign.
Specific to i386 (ifdef __i386__)
fs/ncpfs/ncpsign_kernel.c:58:23: warning: incorrect type in initializer (different signedness)
fs/ncpfs/ncpsign_kernel.c:58:23: expected unsigned int *data2
fs/ncpfs/ncpsign_kernel.c:58:23: got int *<noident>
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: Petr Vandrovec <VANDROVE@vc.cvut.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Harvey Harrison [Mon, 28 Apr 2008 09:14:00 +0000 (02:14 -0700)]
ncpfs: fix sparse warnings in ioctl.c
In both cases, these inode variables arebeing used to test the
server's root inode against NULL. Change them to s_inode.
fs/ncpfs/ioctl.c:391:18: warning: symbol 'inode' shadows an earlier one
fs/ncpfs/ioctl.c:264:28: originally declared here
fs/ncpfs/ioctl.c:441:17: warning: symbol 'inode' shadows an earlier one
fs/ncpfs/ioctl.c:264:28: originally declared here
In this case, we are about to return anyway, just reuse result.
fs/ncpfs/ioctl.c:521:8: warning: symbol 'result' shadows an earlier one
fs/ncpfs/ioctl.c:268:6: originally declared here
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: Petr Vandrovec <VANDROVE@vc.cvut.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Harvey Harrison [Mon, 28 Apr 2008 09:13:59 +0000 (02:13 -0700)]
ncpfs: add prototypes to ncp_fs.h
Removes some externs from C files, noticed from the sparse warnings:
fs/ncpfs/dir.c:90:26: warning: symbol 'ncp_root_dentry_operations' was not declared. Should it be static?
fs/ncpfs/symlink.c:107:5: warning: symbol 'ncp_symlink' was not declared. Should it be static?
fs/ncpfs/symlink.c:101:39: warning: symbol 'ncp_symlink_aops' was not declared. Should it be static?
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: Petr Vandrovec <VANDROVE@vc.cvut.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
WANG Cong [Mon, 28 Apr 2008 09:13:58 +0000 (02:13 -0700)]
uml: clean up arch/um/drivers/ubd_kern.c
Make some global functions and variables static.
And remove some useless declarations for local functions, since we just need
to move their definitions ahead.
[jdike@addtoit.com: checkpatch cleanups] Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
WANG Cong [Mon, 28 Apr 2008 09:13:57 +0000 (02:13 -0700)]
arch/um/os-Linux/sys-i386/task_size.c: improve a bit
Improve this code a bit: check sigaction's return value and remove a useless
fflush().
Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
WANG Cong [Mon, 28 Apr 2008 09:13:57 +0000 (02:13 -0700)]
uml: make several things static
Make several things static, because they no longer need to be global.
Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
WANG Cong [Mon, 28 Apr 2008 09:13:56 +0000 (02:13 -0700)]
uml: remove a useless function
arch/um/drivers/chan_kern.c::chan_out_fd() is not used by anyone. Remove it.
Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
WANG Cong [Mon, 28 Apr 2008 09:13:55 +0000 (02:13 -0700)]
uml: make a function static
arch/um/drivers/chan_kern.c::open_chan() can become static.
Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
WANG Cong [Mon, 28 Apr 2008 09:13:53 +0000 (02:13 -0700)]
arch/um/os-Linux/start_up.c: various improvements.
- lets ptrace_child become void
- adds checking for the return value of change_sig
- moves errors info into stderr instead of stdout.
Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Harvey Harrison [Mon, 28 Apr 2008 09:13:53 +0000 (02:13 -0700)]
uml: replace remaining __FUNCTION__ occurrences
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
WANG Cong [Mon, 28 Apr 2008 09:13:52 +0000 (02:13 -0700)]
arch/um/kernel/um_arch.c: some small improvements
Make some small improvements for arch/um/kernel/um_arch.c.
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
add constfy to pgd_offset() for avoid following warnings.
CC mm/pagewalk.o
mm/pagewalk.c: In function 'walk_page_range':
mm/pagewalk.c:111: warning: passing argument 1 of 'pgd_offset' discards qualifiers from p\
ointer target type
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Matt Mackall <mpm@selenic.com> Cc: "Vegard Nossum" <vegard.nossum@gmail.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrew Morton [Mon, 28 Apr 2008 09:13:48 +0000 (02:13 -0700)]
alpha: teach the compiler that BUG doesn't return
Fix things like this:
security/selinux/netnode.c: In function 'sel_netnode_find':
security/selinux/netnode.c:126: warning: 'idx' may be used uninitialized in this function
security/selinux/netnode.c: In function 'sel_netnode_sid':
security/selinux/netnode.c:225: warning: 'ret' may be used uninitialized in this function
security/selinux/netnode.c:168: warning: 'idx' may be used uninitialized in this function
due to code correctly not expecting BUG() to return.
For some reason this reduces the object code size for that particular file.
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Richard Henderson <rth@twiddle.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Harvey Harrison [Mon, 28 Apr 2008 09:13:46 +0000 (02:13 -0700)]
alpha: replace __inline with inline
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Harvey Harrison [Mon, 28 Apr 2008 09:13:46 +0000 (02:13 -0700)]
alpha: remove remaining __FUNCTION__ occurrences
__FUNCTION__ is gcc-specific, use __func__
The change in pci-iommu,c should be safe as arena has not been assigned
when we get to this point.
Some were within #if 0 blocks, have changed them and left the blocks
as they appear to be debugging infrastructure.
A #define FN __FUNCTION__ was removed and occurances of FN were replaced
with __func__ as well.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Richard Henderson <rth@twiddle.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jim Meyering <meyering@redhat.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With the introduction of per-process securebits, the capabilities-related
prctl callbacks were moved into cap_task_prctl(). Have smack use
cap_task_prctl() so that PR_SET_KEEPCAPS is defined.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With the introduction of per-process securebits, the capabilities-related
prctl callbacks were moved into cap_task_prctl(). Have root_plug use
cap_task_prctl() so that PR_SET_KEEPCAPS is defined.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrew G. Morgan [Mon, 28 Apr 2008 09:13:40 +0000 (02:13 -0700)]
capabilities: implement per-process securebits
Filesystem capability support makes it possible to do away with (set)uid-0
based privilege and use capabilities instead. That is, with filesystem
support for capabilities but without this present patch, it is (conceptually)
possible to manage a system with capabilities alone and never need to obtain
privilege via (set)uid-0.
Of course, conceptually isn't quite the same as currently possible since few
user applications, certainly not enough to run a viable system, are currently
prepared to leverage capabilities to exercise privilege. Further, many
applications exist that may never get upgraded in this way, and the kernel
will continue to want to support their setuid-0 base privilege needs.
Where pure-capability applications evolve and replace setuid-0 binaries, it is
desirable that there be a mechanisms by which they can contain their
privilege. In addition to leveraging the per-process bounding and inheritable
sets, this should include suppressing the privilege of the uid-0 superuser
from the process' tree of children.
The feature added by this patch can be leveraged to suppress the privilege
associated with (set)uid-0. This suppression requires CAP_SETPCAP to
initiate, and only immediately affects the 'current' process (it is inherited
through fork()/exec()). This reimplementation differs significantly from the
historical support for securebits which was system-wide, unwieldy and which
has ultimately withered to a dead relic in the source of the modern kernel.
With this patch applied a process, that is capable(CAP_SETPCAP), can now drop
all legacy privilege (through uid=0) for itself and all subsequently
fork()'d/exec()'d children with:
prctl(PR_SET_SECUREBITS, 0x2f);
This patch represents a no-op unless CONFIG_SECURITY_FILE_CAPABILITIES is
enabled at configure time.
[akpm@linux-foundation.org: fix uninitialised var warning]
[serue@us.ibm.com: capabilities: use cap_task_prctl when !CONFIG_SECURITY] Signed-off-by: Andrew G. Morgan <morgan@kernel.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Reviewed-by: James Morris <jmorris@namei.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Paul Moore <paul.moore@hp.com> Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/nommu.c: return 0 from kobjsize with invalid objects
Don't perform kobjsize operations on objects the kernel doesn't manage.
On Blackfin, drivers can get dma coherent memory by calling a function
dma_alloc_coherent(). We do this in nommu by configuring a chunk of uncached
memory at the top of memory.
Since we don't want the kernel to use the uncached memory, we lie to the
kernel, and tell it that it's max memory is between 0, and the start of the
uncached dma coherent section.
this all works well, until this memory gets exposed into userspace (with a
frame buffer), when you look at the process's maps, it shows the framebuf:
This is outside the "normal" range for the kernel. When the kernel tries to
find the size of this object (when you run ps), it dies in nommu.c in
kobjsize.
BUG_ON(page->index >= MAX_ORDER);
since the page we are referring to is outside what the kernel thinks is it's
max valid memory.
root:~> while [ 1 ]; ps > /dev/null; done
kernel BUG at mm/nommu.c:119!
Kernel panic - not syncing: BUG!
We fixed this by adding a check to reject out of range object pointers as it
already does that for NULL pointers.
Signed-off-by: Michael Hennerich <Michael.Hennerich@analog.com> Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Li Zefan [Mon, 28 Apr 2008 09:13:35 +0000 (02:13 -0700)]
oom_kill: remove unused parameter in badness()
In commit 4c4a22148909e4c003562ea7ffe0a06e26919e3c, we moved the
memcontroller-related code from badness() to select_bad_process(), so the
parameter 'mem' in badness() is unused now.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is to free memmaps which is allocated by bootmem.
Freeing usemap is not necessary. The pages of usemap may be necessary for
other sections.
If removing section is last section on the node, its section is the final user
of usemap page. (usemaps are allocated on its section by previous patch.) But
it shouldn't be freed too, because the section must be logical offline state
which all pages are isolated against page allocater. If it is freed, page
alloctor may use it which will be removed physically soon. It will be
disaster. So, this patch keeps it as it is.
memory hotplug: allocate usemap on the section with pgdat
Usemaps are allocated on the section which has pgdat by this.
Because usemap size is very small, many other sections usemaps are allocated
on only one page. If a section has usemap, it can't be removed until removing
other sections. This dependency is not desirable for memory removing.
Pgdat has similar feature. When a section has pgdat area, it must be the last
section for removing on the node. So, if section A has pgdat and section B
has usemap for section A, Both sections can't be removed due to dependency
each other.
To solve this issue, this patch collects usemap on same section with pgdat.
If other sections doesn't have any dependency, this section will be able to be
removed finally.
To free memmap easier, this patch aligns it to page size. Bootmem allocater
may mix some objects in one pages. It's not good for freeing memmap of memory
hot-remove.
This patch set is to free pages which is allocated by bootmem for
memory-hotremove. Some structures of memory management are allocated by
bootmem. ex) memmap, etc.
To remove memory physically, some of them must be freed according to
circumstance. This patch set makes basis to free those pages, and free
memmaps.
Basic my idea is using remain members of struct page to remember information
of users of bootmem (section number or node id). When the section is
removing, kernel can confirm it. By this information, some issues can be
solved.
1) When the memmap of removing section is allocated on other
section by bootmem, it should/can be free.
2) When the memmap of removing section is allocated on the
same section, it shouldn't be freed. Because the section has to be
logical memory offlined already and all pages must be isolated against
page allocater. If it is freed, page allocator may use it which will
be removed physically soon.
3) When removing section has other section's memmap,
kernel will be able to show easily which section should be removed
before it for user. (Not implemented yet)
4) When the above case 2), the page isolation will be able to check and skip
memmap's page when logical memory offline (offline_pages()).
Current page isolation code fails in this case because this page is
just reserved page and it can't distinguish this pages can be
removed or not. But, it will be able to do by this patch.
(Not implemented yet.)
5) The node information like pgdat has similar issues. But, this
will be able to be solved too by this.
(Not implemented yet, but, remembering node id in the pages.)
Fortunately, current bootmem allocator just keeps PageReserved flags,
and doesn't use any other members of page struct. The users of
bootmem doesn't use them too.
This patch:
This is to register information which is node or section's id. Kernel can
distinguish which node/section uses the pages allcated by bootmem. This is
basis for hot-remove sections or nodes.
Huge ptes have a special type on s390 and cannot be handled with the standard
pte functions in certain cases, e.g. because of a different location of the
invalid bit. This patch adds some new architecture- specific functions to
hugetlb common code, as a prerequisite for the s390 large page support.
This won't affect other architectures in functionality, but I need to add some
new dummy inline functions to the headers.
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A cow break on a hugetlbfs page with page_count > 1 will set a new pte with
set_huge_pte_at(), w/o any tlb flush operation. The old pte will remain in
the tlb and subsequent write access to the page will result in a page fault
loop, for as long as it may take until the tlb is flushed from somewhere else.
This patch introduces an architecture-specific huge_ptep_clear_flush()
function, which is called before the the set_huge_pte_at() in hugetlb_cow().
ATTENTION: This is just a nop on all architectures for now, the s390
implementation will come with our large page patch later. Other architectures
should define their own huge_ptep_clear_flush() if needed.
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch moves all architecture functions for hugetlb to architecture header
files (include/asm-foo/hugetlb.h) and converts all macros to inline functions.
It also removes (!) ARCH_HAS_HUGEPAGE_ONLY_RANGE,
ARCH_HAS_HUGETLB_FREE_PGD_RANGE, ARCH_HAS_PREPARE_HUGEPAGE_RANGE,
ARCH_HAS_SETCLEAR_HUGE_PTE and ARCH_HAS_HUGETLB_PREFAULT_HOOK.
Getting rid of the ARCH_HAS_xxx #ifdef and macro fugliness should increase
readability and maintainability, at the price of some code duplication. An
asm-generic common part would have reduced the loc, but we would end up with
new ARCH_HAS_xxx defines eventually.
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lee Schermerhorn [Mon, 28 Apr 2008 09:13:26 +0000 (02:13 -0700)]
mempolicy: use struct mempolicy pointer in shmem_sb_info
This patch replaces the mempolicy mode, mode_flags, and nodemask in the
shmem_sb_info struct with a struct mempolicy pointer, initialized to NULL.
This removes dependency on the details of mempolicy from shmem.c and hugetlbfs
inode.c and simplifies the interfaces.
mpol_parse_str() in mempolicy.c is changed to return, via a pointer to a
pointer arg, a struct mempolicy pointer on success. For MPOL_DEFAULT, the
returned pointer is NULL. Further, mpol_parse_str() now takes a 'no_context'
argument that causes the input nodemask to be stored in the w.user_nodemask of
the created mempolicy for use when the mempolicy is installed in a tmpfs inode
shared policy tree. At that time, any cpuset contextualization is applied to
the original input nodemask. This preserves the previous behavior where the
input nodemask was stored in the superblock. We can think of the returned
mempolicy as "context free".
Because mpol_parse_str() is now calling mpol_new(), we can remove from
mpol_to_str() the semantic checks that mpol_new() already performs.
Add 'no_context' parameter to mpol_to_str() to specify that it should format
the nodemask in w.user_nodemask for 'bind' and 'interleave' policies.
Change mpol_shared_policy_init() to take a pointer to a "context free" struct
mempolicy and to create a new, "contextualized" mempolicy using the mode,
mode_flags and user_nodemask from the input mempolicy.
Note: we know that the mempolicy passed to mpol_to_str() or
mpol_shared_policy_init() from a tmpfs superblock is "context free". This
is currently the only instance thereof. However, if we found more uses for
this concept, and introduced any ambiguity as to whether a mempolicy was
context free or not, we could add another internal mode flag to identify
context free mempolicies. Then, we could remove the 'no_context' argument
from mpol_to_str().
Added shmem_get_sbmpol() to return a reference counted superblock mempolicy,
if one exists, to pass to mpol_shared_policy_init(). We must add the
reference under the sb stat_lock to prevent races with replacement of the mpol
by remount. This reference is removed in mpol_shared_policy_init().
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: another build fix]
[akpm@linux-foundation.org: yet another build fix] Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lee Schermerhorn [Mon, 28 Apr 2008 09:13:24 +0000 (02:13 -0700)]
mempolicy: support mpol=local tmpfs mount option
For tmpfs/shmem shared policies, MPOL_DEFAULT is not necessarily equivalent to
"local allocation". Because shared policies are at the same "scope" level
[see Documentation/vm/numa_memory_policy.txt], as vma policies MPOL_DEFAULT
means "fall back to current task policy".
This patch extends the memory policy string parsing function to display
"local" for MPOL_PREFERRED + MPOL_F_LOCAL. This allows one to specify local
allocation as the default policy for shared memory areas via the tmpfs mpol
mount option, regardless of the current task's policy.
Also, "local" is now displayed for this policy. This patch allows us to
accept the same input format as the display.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lee Schermerhorn [Mon, 28 Apr 2008 09:13:23 +0000 (02:13 -0700)]
mempolicy: rework shmem mpol parsing and display
mm/shmem.c currently contains functions to parse and display memory policy
strings for the tmpfs 'mpol' mount option. Move this to mm/mempolicy.c with
the rest of the mempolicy support. With subsequent patches, we'll be able to
remove knowledge of the details [mode, flags, policy, ...] completely from
shmem.c
1) replace shmem_parse_mpol() in mm/shmem.c with mpol_parse_str() in
mm/mempolicy.c. Rework to use the policy_types[] array [used by
mpol_to_str()] to look up mode by name.
2) use mpol_to_str() to format policy for shmem_show_mpol(). mpol_to_str()
expects a pointer to a struct mempolicy, so temporarily construct one.
This will be replaced with a reference to a struct mempolicy in the tmpfs
superblock in a subsequent patch.
NOTE 1: I changed mpol_to_str() to use a colon ':' rather than an equal
sign '=' as the nodemask delimiter to match mpol_parse_str() and the
tmpfs/shmem mpol mount option formatting that now uses mpol_to_str(). This
is a user visible change to numa_maps, but then the addition of the mode
flags already changed the display. It makes sense to me to have the mounts
and numa_maps display the policy in the same format. However, if anyone
objects strongly, I can pass the desired nodemask delimeter as an arg to
mpol_to_str().
Note 2: Like show_numa_map(), I don't check the return code from
mpol_to_str(). I do use a longer buffer than the one provided by
show_numa_map(), which seems to have sufficed so far.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mpol-to-str() formats memory policies into printable strings. Currently this
is only used to display "numa_maps". A subsequent patch will use
mpol_to_str() for formatting tmpfs [shmem] mpol mount options, allowing us to
remove essentially duplicate code in mm/shmem.c. This patch cleans up
mpol_to_str() generally and in preparation for that patch.
1) show_numa_maps() is not checking the return code from mpol_to_str().
There's not a lot we can do in this context if mpol_to_str() did return the
error [insufficient space in buffer]. Proposed "solution": just check,
under DEBUG_VM, that callers are providing sufficient buffer space for the
policy, flags, and a few nodes. This way, we'll get some display.
show_numa_maps() is providing a 50-byte buffer, so it won't trip this
check. 50-bytes should be sufficient unless one has a large number of
nodes in a very sparse nodemask.
2) The display of the new mode flags ["static" & "relative"] was set up to
display multiple flags, separated by a "bar" '|'. However, this support is
incomplete--e.g., need_bar was never incremented; and currently, these two
flags are mutually exclusive. So remove the "bar" support, for now, and
only display one flag.
3) Use snprint() to format flags, so as not to overflow the buffer. Not
that it's ever happed, AFAIK.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lee Schermerhorn [Mon, 28 Apr 2008 09:13:21 +0000 (02:13 -0700)]
mempolicy: use MPOL_F_LOCAL to Indicate Preferred Local Policy
Now that we're using "preferred local" policy for system default, we need to
make this as fast as possible. Because of the variable size of the mempolicy
structure [based on size of nodemasks], the preferred_node may be in a
different cacheline from the mode. This can result in accessing an extra
cacheline in the normal case of system default policy. Suspect this is the
cause of an observed 2-3% slowdown in page fault testing relative to kernel
without this patch series.
To alleviate this, use an internal mode flag, MPOL_F_LOCAL in the mempolicy
flags member which is guaranteed [?] to be in the same cacheline as the mode
itself.
Verified that reworked mempolicy now performs slightly better on 25-rc8-mm1
for both anon and shmem segments with system default and vma [preferred local]
policy.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lee Schermerhorn [Mon, 28 Apr 2008 09:13:20 +0000 (02:13 -0700)]
mempolicy: mPOL_PREFERRED cleanups for "local allocation"
Here are a couple of "cleanups" for MPOL_PREFERRED behavior when
v.preferred_node < 0 -- i.e., "local allocation":
1) [do_]get_mempolicy() calls the now renamed get_policy_nodemask()
to fetch the nodemask associated with a policy. Currently,
get_policy_nodemask() returns the set of nodes with memory, when
the policy 'mode' is 'PREFERRED, and the preferred_node is < 0.
Change to return an empty nodemask, as this is what was specified
to achieve "local allocation".
2) When a task is moved into a [new] cpuset, mpol_rebind_policy() is
called to adjust any task and vma policy nodes to be valid in the
new cpuset. However, when the policy is MPOL_PREFERRED, and the
preferred_node is <0, no rebind is necessary. The "local allocation"
indication is valid in any cpuset. Existing code will "do the right
thing" because node_remap() will just return the argument node when
it is outside of the valid range of node ids. However, I think it is
clearer and cleaner to skip the remap explicitly in this case.
3) mpol_to_str() produces a printable, "human readable" string from a
struct mempolicy. For MPOL_PREFERRED with preferred_node <0, show
"local", as this indicates local allocation, as the task migrates
among nodes. Note that this matches the usage of "local allocation"
in libnuma() and numactl. Without this change, I believe that node_set()
[via set_bit()] will set bit 31, resulting in a misleading display.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lee Schermerhorn [Mon, 28 Apr 2008 09:13:18 +0000 (02:13 -0700)]
mempolicy: use MPOL_PREFERRED for system-wide default policy
Currently, when one specifies MPOL_DEFAULT via a NUMA memory policy API
[set_mempolicy(), mbind() and internal versions], the kernel simply installs a
NULL struct mempolicy pointer in the appropriate context: task policy, vma
policy, or shared policy. This causes any use of that policy to "fall back"
to the next most specific policy scope.
The only use of MPOL_DEFAULT to mean "local allocation" is in the system
default policy. This requires extra checks/cases for MPOL_DEFAULT in many
mempolicy.c functions.
There is another, "preferred" way to specify local allocation via the APIs.
That is using the MPOL_PREFERRED policy mode with an empty nodemask.
Internally, the empty nodemask gets converted to a preferred_node id of '-1'.
All internal usage of MPOL_PREFERRED will convert the '-1' to the id of the
node local to the cpu where the allocation occurs.
System default policy, except during boot, is hard-coded to "local
allocation". By using the MPOL_PREFERRED mode with a negative value of
preferred node for system default policy, MPOL_DEFAULT will never occur in the
'policy' member of a struct mempolicy. Thus, we can remove all checks for
MPOL_DEFAULT when converting policy to a node id/zonelist in the allocation
paths.
In slab_node() return local node id when policy pointer is NULL. No need to
set a pol value to take the switch default. Replace switch default with
BUG()--i.e., shouldn't happen.
With this patch MPOL_DEFAULT is only used in the APIs, including internal
calls to do_set_mempolicy() and in the display of policy in
/proc/<pid>/numa_maps. It always means "fall back" to the the next most
specific policy scope. This simplifies the description of memory policies
quite a bit, with no visible change in behavior.
get_mempolicy() continues to return MPOL_DEFAULT and an empty nodemask when
the requested policy [task or vma/shared] is NULL. These are the values one
would supply via set_mempolicy() or mbind() to achieve that condition--default
behavior.
This patch updates Documentation to reflect this change.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After further discussion with Christoph Lameter, it has become clear that my
earlier attempts to clean up the mempolicy reference counting were a bit of
overkill in some areas, resulting in superflous ref/unref in what are usually
fast paths. In other areas, further inspection reveals that I botched the
unref for interleave policies.
A separate patch, suitable for upstream/stable trees, fixes up the known
errors in the previous attempt to fix reference counting.
This patch reworks the memory policy referencing counting and, one hopes,
simplifies the code. Maybe I'll get it right this time.
See the update to the numa_memory_policy.txt document for a discussion of
memory policy reference counting that motivates this patch.
Summary:
Lookup of mempolicy, based on (vma, address) need only add a reference for
shared policy, and we need only unref the policy when finished for shared
policies. So, this patch backs out all of the unneeded extra reference
counting added by my previous attempt. It then unrefs only shared policies
when we're finished with them, using the mpol_cond_put() [conditional put]
helper function introduced by this patch.
Note that shmem_swapin() calls read_swap_cache_async() with a dummy vma
containing just the policy. read_swap_cache_async() can call alloc_page_vma()
multiple times, so we can't let alloc_page_vma() unref the shared policy in
this case. To avoid this, we make a copy of any non-null shared policy and
remove the MPOL_F_SHARED flag from the copy. This copy occurs before reading
a page [or multiple pages] from swap, so the overhead should not be an issue
here.
I introduced a new static inline function "mpol_cond_copy()" to copy the
shared policy to an on-stack policy and remove the flags that would require a
conditional free. The current implementation of mpol_cond_copy() assumes that
the struct mempolicy contains no pointers to dynamically allocated structures
that must be duplicated or reference counted during copy.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Document mempolicy return value reference semantics assumed by the rest of the
mempolicy code for the set_ and get_policy vm_ops in <linux/mm.h>--where the
prototypes are defined--to inform any future mempolicy vm_op writers what the
rest of the subsystem expects of them.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lee Schermerhorn [Mon, 28 Apr 2008 09:13:13 +0000 (02:13 -0700)]
mempolicy: mark shared policies for unref
As part of yet another rework of mempolicy reference counting, we want to be
able to identify shared policies efficiently, because they have an extra ref
taken on lookup that needs to be removed when we're finished using the policy.
Note: the extra ref is required because the policies are
shared between tasks/processes and can be changed/freed
by one task while another task is using them--e.g., for
page allocation.
Building on David Rientjes mempolicy "mode flags" enhancement, this patch
indicates a "shared" policy by setting a new MPOL_F_SHARED flag in the flags
member of the struct mempolicy added by David. MPOL_F_SHARED, and any future
"internal mode flags" are reserved from bit zero up, as they will never be
passed in the upper bits of the mode argument of a mempolicy API.
I set the MPOL_F_SHARED flag when the policy is installed in the shared policy
rb-tree. Don't need/want to clear the flag when removing from the tree as the
mempolicy is freed [unref'd] internally to the sp_delete() function. However,
a task could hold another reference on this mempolicy from a prior lookup. We
need the MPOL_F_SHARED flag to stay put so that any tasks holding a ref will
unref, eventually freeing, the mempolicy.
A later patch in this series will introduce a function to conditionally unref
[mpol_free] a policy. The MPOL_F_SHARED flag is one reason [currently the
only reason] to unref/free a policy via the conditional free.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
projects / linux-2.6 / log