The kernel's implementation of notifier chains is unsafe. There is no
protection against entries being added to or removed from a chain while the
chain is in use. The issues were discussed in this thread:
http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2
We noticed that notifier chains in the kernel fall into two basic usage
classes:
"Blocking" chains are always called from a process context
and the callout routines are allowed to sleep;
"Atomic" chains can be called from an atomic context and
the callout routines are not allowed to sleep.
We decided to codify this distinction and make it part of the API. Therefore
this set of patches introduces three new, parallel APIs: one for blocking
notifiers, one for atomic notifiers, and one for "raw" notifiers (which is
really just the old API under a new name). New kinds of data structures are
used for the heads of the chains, and new routines are defined for
registration, unregistration, and calling a chain. The three APIs are
explained in include/linux/notifier.h and their implementation is in
kernel/sys.c.
With atomic and blocking chains, the implementation guarantees that the chain
links will not be corrupted and that chain callers will not get messed up by
entries being added or removed. For raw chains the implementation provides no
guarantees at all; users of this API must provide their own protections. (The
idea was that situations may come up where the assumptions of the atomic and
blocking APIs are not appropriate, so it should be possible for users to
handle these things in their own way.)
There are some limitations, which should not be too hard to live with. For
atomic/blocking chains, registration and unregistration must always be done in
a process context since the chain is protected by a mutex/rwsem. Also, a
callout routine for a non-raw chain must not try to register or unregister
entries on its own chain. (This did happen in a couple of places and the code
had to be changed to avoid it.)
Since atomic chains may be called from within an NMI handler, they cannot use
spinlocks for synchronization. Instead we use RCU. The overhead falls almost
entirely in the unregister routine, which is okay since unregistration is much
less frequent that calling a chain.
Here is the list of chains that we adjusted and their classifications. None
of them use the raw API, so for the moment it is only a placeholder.
ATOMIC CHAINS
-------------
arch/i386/kernel/traps.c: i386die_chain
arch/ia64/kernel/traps.c: ia64die_chain
arch/powerpc/kernel/traps.c: powerpc_die_chain
arch/sparc64/kernel/traps.c: sparc64die_chain
arch/x86_64/kernel/traps.c: die_chain
drivers/char/ipmi/ipmi_si_intf.c: xaction_notifier_list
kernel/panic.c: panic_notifier_list
kernel/profile.c: task_free_notifier
net/bluetooth/hci_core.c: hci_notifier
net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_chain
net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_expect_chain
net/ipv6/addrconf.c: inet6addr_chain
net/netfilter/nf_conntrack_core.c: nf_conntrack_chain
net/netfilter/nf_conntrack_core.c: nf_conntrack_expect_chain
net/netlink/af_netlink.c: netlink_chain
BLOCKING CHAINS
---------------
arch/powerpc/platforms/pseries/reconfig.c: pSeries_reconfig_chain
arch/s390/kernel/process.c: idle_chain
arch/x86_64/kernel/process.c idle_notifier
drivers/base/memory.c: memory_chain
drivers/cpufreq/cpufreq.c cpufreq_policy_notifier_list
drivers/cpufreq/cpufreq.c cpufreq_transition_notifier_list
drivers/macintosh/adb.c: adb_client_list
drivers/macintosh/via-pmu.c sleep_notifier_list
drivers/macintosh/via-pmu68k.c sleep_notifier_list
drivers/macintosh/windfarm_core.c wf_client_list
drivers/usb/core/notify.c usb_notifier_list
drivers/video/fbmem.c fb_notifier_list
kernel/cpu.c cpu_chain
kernel/module.c module_notify_list
kernel/profile.c munmap_notifier
kernel/profile.c task_exit_notifier
kernel/sys.c reboot_notifier_list
net/core/dev.c netdev_chain
net/decnet/dn_dev.c: dnaddr_chain
net/ipv4/devinet.c: inetaddr_chain
It's possible that some of these classifications are wrong. If they are,
please let us know or submit a patch to fix them. Note that any chain that
gets called very frequently should be atomic, because the rwsem read-locking
used for blocking chains is very likely to incur cache misses on SMP systems.
(However, if the chain's callout routines may sleep then the chain cannot be
atomic.)
The patch set was written by Alan Stern and Chandra Seetharaman, incorporating
material written by Keith Owens and suggestions from Paul McKenney and Andrew
Morton.
[jes@sgi.com: restructure the notifier chain initialization macros]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Create compat_sys_adjtimex and use it an all appropriate places.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We had a copy of the compatibility version of struct timex in each 64 bit
architecture. This patch just creates a global one and replaces all the
usages of the old ones.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kyle McMartin <kyle@parisc-linux.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
include/linux/platform.h contained nothing that was actually used except
the default_idle() prototype, and is therefore removed by this patch.
This patch does the following with the platform specific default_idle()
functions on different architectures:
- remove the unused function:
- parisc
- sparc64
- make the needlessly global function static:
- arm
- h8300
- m68k
- m68knommu
- s390
- v850
- x86_64
- add a prototype in asm/system.h:
- cris
- i386
- ia64
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Patrick Mochel <mochel@digitalimplant.org>
Acked-by: Kyle McMartin <kyle@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When we stop allocating percpu memory for not-possible CPUs we must not touch
the percpu data for not-possible CPUs at all. The correct way of doing this
is to test cpu_possible() or to use for_each_cpu().
This patch is a kernel-wide sweep of all instances of NR_CPUS. I found very
few instances of this bug, if any. But the patch converts lots of open-coded
test to use the preferred helper macros.
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Acked-by: Kyle McMartin <kyle@parisc-linux.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Christian Zankel <chris@zankel.net>
Cc: Philippe Elie <phil.el@wanadoo.fr>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Jens Axboe <axboe@suse.de>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
set_page_count usage outside mm/ is limited to setting the refcount to 1.
Remove set_page_count from outside mm/, and replace those users with
init_page_count() and set_page_refcounted().
This allows more debug checking, and tighter control on how code is allowed
to play around with page->_count.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
CONFIG_TIME_LOW_RES is a temporary way for architectures to signal that
they simply return xtime in do_gettimeoffset(). In this corner-case we
want to round up by resolution when starting a relative timer, to avoid
short timeouts. This will go away with the GTOD framework.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
parisc defines ARCH_WANT_STAT64, so we want to use fstatat64. It does not
appear that it needs to be ENTRY_COMP, because struct stat64 is the same
on both 32-bit and 64-bit (unlike on other platforms which did define a
compat_sys_fstatat64.)
Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Swap out pselect6/ppoll for ni_syscall for now. We also have to switch
the macro to ENTRY_SAME since compat_sys_ni_syscall does not exist.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Userspace can alter the string after the kernel has run strlen_user().
Also: the strlen_user() return value includes the \0, so fix that.
Also: handle EFAULT from strlen_user().
It's unlikely anyone is using this code. Very, very unlikely. If I
remember correctly, CONFIG_HPUX turns this code on, but one would actually
need CONFIG_BINFMT_SOM to load a binary that could cause a problem, and
BINFMT_SOM has had an #error in it for quite some time.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Wire up some new syscalls that have been merged upstream,
o inotify
o openat et al
o pselect6/ppoll
o migrate_pages
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
parisc was previously displaying both the mm/Kconfig memory model
menu, and its own prompt. Remove prompt and have CONFIG_64BIT toggle
between DISCONTIGMEM and FLATMEM. Also remove the EXPERIMENTAL from
discontigmem support... It's been running fine for months (years?)
now.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Add enough arch-specific compat signals code to enable parisc64
to compile and boot out of the mainline tree. There are likely still
many dragons here, but this is a start to squashing the last
big difference between the mainline tree and the parisc-linux tree.
The remaining bugs can be squashed as they come up.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Use CONFIG_DEBUG_KERNEL to catch kernel code which tries to access
__init data after it is freed. When CONFIG_DEBUG_KERNEL is not set
this also cleans up a WARN_ON at boot time. Also remove some dead
code from mm/init.c
Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Add the parisc version of the "mark rodata section read only" patches.
Based on code from and Signed-off-by Arjan van de Ven
<arjan@infradead.org>, Ingo Molnar <mingo@elte.hu>, Andi Kleen <ak@muc.de>,
Andrew Morton <akpm@osdl.org>, Linus Torvalds <torvalds@osdl.org>.
Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Remove the lock_kernel/unlock_kernel pair in the ioctl method. It
plainly wasn't protecting anything.
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Define a chassis_power_off routine that machines which have a way
to turn off the power supply can hook into. Formerly they were
using pm_power_off, which is now being used by generic code. Make
lasi.c use chassis_power_off instead of pm_power_off.
Note, all machines need to call machine_power_off so that the
switch can power off the machine, though halt -p may not necessarily
be able to work properly on the machine.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Remove a bunch of obsolete code from process.c, these routines were
likely imported from the i386 version of process.c when the port
started. The routines are only used in floppy.c, which I seriously
doubt will ever work on parisc, due to architectural assumptions.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Move the EXPORT_SYMBOL() of pm_power_off from parisc_ksyms.c to the
location of its definition in process.c
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Avoid compiler warning for unused variables on 32bit kernels by
conditionalizing the local variables on CONFIG_64BIT. PCI_HOST_ADDR()
only uses the hba argument on 64bit compiles.
Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Instead of wrapping the define of COMMAND_GLOBAL in #ifdef __LP64__
use the F_EXTEND() macro defined in asm/io.h, which is the preferred
way of extending mmio space addresses for either 32 or 64 bit machines.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Fix our trap handler to issue the correct floating point exception
for both types of invalid trap.
Signed-off-by: James Bottomley <jejb@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Drop the unused do_check_pgt_cache routine from mm/init.c and its
prototype in asm/pgalloc.h
Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Remove two unnecessary extern declarations from asm/pci.h.
They collide with what gcc4.0 assumed was static (and should be static).
Found by Joel Soete.
Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Helge,
o Convert a bunch of kmalloc/memset uses to kzalloc.
o pci.c: Add some __read_mostly annotations.
o pci.c: Move constant pci_post_reset_delay to asm/pci.h
o grfioctl.h: Add A4450A to comment of CRT_ID_VISUALIZE_EG.
o Add some consts to perf.c/perf_images.h
Matthew,
o sticore.c: Add some consts to suppress compile warnings.
Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Update b180_defconfig to be more usable on other similar machines.
Enabling Lasi 82596, Harmony, Mux console, CCIO, HPPB, etc., means
this config is suitable for not only BXXX machines, but also CXXX
and JXXX class machines.
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Make flush_tlb_all_local take a void * so it doesn't have to be cast
when using on_each_cpu(). This becomes a problem when on_each_cpu
is a macro.
Also remove the prototype of flush_tlb_all_local from .c files.
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Adds the ability to disability packet split at compile time and use the legacy receive path on PCI express hardware. Made this a CONFIG option and modified the Kconfig, to reflect the new option.
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: John Ronciak <john.ronciak@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
arch: Use <linux/capability.h> where capable() is used.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Cleanup vmlinux.lds.S by using STABS_DEBUG macro from vmlinux.lds.h
instead of repeating the sections.
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Fix Dino reporting on J2240. This particular machine thought it
had a Cujo. Also add J2240 Dino chip to the hp_hardware_list.
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
max_low_pfn was not being set in arch/parisc/mm/init.c, causing severe
problems whenever anything tried to use BLK_BOUNCE_HIGH. Set it to
max_pfn like other similar architectures do.
Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Make knapps work with its 64MB gfx card. I probably just broke another
machine in the process, but assuming 64MB when 64MB aligned is probably
safer than assuming 32MB all the time.
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Fixup ioremap a bit. It seems to work on 32-bit kernels, but fails
miserably on the first ioremapped access on 64-bit kernels. Also, having
STI enabled causes it to fail. Probably because we're passing an ioremapped
region to a real-mode STI call...
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Make flush_data_cache_local, flush_instruction_cache_local and
flush_tlb_all_local take a void * so they don't have to be cast
when using on_each_cpu(). This becomes a problem when on_each_cpu
is a macro (as it is in current -mm).
Also move the prototype of flush_tlb_all_local into tlbflush.h and
remove its declaration from .c files.
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Flag a whole bunch of things as __read_mostly on parisc. Also flag a few
branches as unlikely() and cleanup a bit of code.
Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Now that all these entries in the arch ioctl32.c files are gone [1], we can
build fs/compat_ioctl.c as a normal object and kill tons of cruft. We need a
special do_ioctl32_pointer handler for s390 so the compat_ptr call is done.
This is not needed but harmless on all other architectures. Also remove some
superflous includes in fs/compat_ioctl.c
Tested on ppc64.
[1] parisc still had it's PPP handler left, which is not fully correct
for ppp and besides that ppp uses the generic SIOCPRIV ioctl so it'd
kick in for all netdevice users. We can introduce a proper handler
in one of the next patch series by adding a compat_ioctl method to
struct net_device but for now let's just kill it - parisc doesn't
compile in mainline anyway and I don't want this to block this
patchset.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@debian.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch implements generic handling of RTC_IRQP_READ32, RTC_IRQP_SET32,
RTC_EPOCH_READ32 and RTC_EPOCH_SET32 in fs/compat_ioctl.c. It's based on the
x86_64 code which needed a little massaging to be endian-clean.
parisc used COMPAT_IOCTL or generic w_long handlers for these whichce is wrong
and can't work because the ioctls encode sizeof(unsigned long) in their ioctl
number. parisc also duplicated COMPAT_IOCTL entries for other rtc ioctls
which I remove in this patch, too.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Matthew Wilcox <matthew@wil.cx>
Acked-by: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Configurable 16-bit UID and friends support
This allows turning off the legacy 16 bit UID interfaces on embedded platforms.
text data bss dec hex filename
3330172 529036 190556 4049764 3dcb64 vmlinux-baseline
3328268 529040 190556 4047864 3dc3f8 vmlinux
From: Adrian Bunk <bunk@stusta.de>
UID16 was accidentially disabled for !EMBEDDED.
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove drm compat_ioctl handlers. The drm drivers have proper
compat_ioctl methods these days.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Move PA perf driver over to ->compat_ioctl.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Randolph Chung <tausq@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Fix some compile problems:
- ret wasn't being initialised in all code paths
- I'm pretty sure 'goto out' should have been 'goto out_tsk'
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Improve the error message when we get a clashing mod path, and
actually display the IODC data and path for the conflicting device.
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Return PDC_OK when device registration fails so that we enumerate all
subsequent devices, even when we get two devices with the same hardware
path (which should never happen, but does with at least one revision of
rp8400 firmware).
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Document clobbers and args in entry.S and syscall.S.
entry.S: Add comment to indicate that cr27 may recycle and EDEADLOCK
detection is not 100% correct. Since this is only enabled when using
ENABLE_LWS_DEBUG, the user is warned by the comment.
Signed-off-by: Carlos O'Donell <carlos@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Make the "redirecting irq" message to not display on the console by
setting the severity to KERN_DEBUG. The console was basically unusable.
Signed-off-by: Ryan Bradetich <rbrad@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Alan Stern
Akinobu Mita
Stephen Rothwell
Adrian Bunk
Andrew Morton
Nick Piggin
Ingo Molnar
Kyle McMartin
Kyle McMartin
Helge Deller
Matthew Wilcox
James Bottomley
Grant Grundler
Jesse Brandeburg
Russell King
Al Viro
Randy Dunlap
Christoph Hellwig
Matt Mackall
Carlos O'Donell
Ryan Bradetich