| Age | Commit message (Collapse) | Author |
|---|
|
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>
|
|
Patch from Tony Lindgren
This patch fixes the low-level IO init for omap1 boards.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
Patch from Tony Lindgren
This patch adds the missing cache flushes to common low-level
init that are needed to access the IO region. These flushes
are normally done at the end of devicemaps_init(), but we
need to detect the OMAP core type early.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
This patch fixes OMAP clock framework to use clk_enable/disable
instead of clk_use/unuse as specified in include/linux/clk.h.
Signed-off-by: Tony Lindgren <tony@atomide.com>
|
|
This patch fixes OMAP clock framework to use clk_enable/disable
instead of clk_use/unuse as specified in include/linux/clk.h.
Signed-off-by: Tony Lindgren <tony@atomide.com>
|
|
Patch from Nicolas Pitre
This field is redundent since it must be equal to PHYS_OFFSET anyway.
Now that no code uses it anymore, mark it deprecated and remove all
initializations from the tree.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
Additionally, one comment was reformulated by Joe Perches <joe@perches.com>.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
|
|
Some ARM platforms have the ability to program the interrupt controller to
detect various interrupt edges and/or levels. For some platforms, this is
critical to setup correctly, particularly those which the setting is dependent
on the device.
Currently, ARM drivers do (eg) the following:
err = request_irq(irq, ...);
set_irq_type(irq, IRQT_RISING);
However, if the interrupt has previously been programmed to be level sensitive
(for whatever reason) then this will cause an interrupt storm.
Hence, if we combine set_irq_type() with request_irq(), we can then safely set
the type prior to unmasking the interrupt. The unfortunate problem is that in
order to support this, these flags need to be visible outside of the ARM
architecture - drivers such as smc91x need these flags and they're
cross-architecture.
Finally, the SA_TRIGGER_* flag passed to request_irq() should reflect the
property that the device would like. The IRQ controller code should do its
best to select the most appropriate supported mode.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
|
|
This is needs to be visible to other architectures using the AMBA
bus and peripherals.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
Patch from Tony Lindgren
This patch syncs the mainline kernel with linux-omap tree.
The highlights of the patch are:
- Omap1 serial pport and framebuffer init updates by Imre Deak
- Add support for omap310 processor and Palm Tungsten E PDA
by Laurent Gonzales, Romain Goyet, et al. Omap310 and
omap1510 processors are now handled as omap15xx.
- Omap1 specific changes to shared omap clock framework
by Tony Lindgren
- Omap1 specific changes to shared omap pin mux framework
by Tony Lindgren
- Other misc fixes, such as update memory timings for smc91x,
omap1 specific device initialization etc.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
This patch removes almost all inclusions of linux/version.h. The 3
#defines are unused in most of the touched files.
A few drivers use the simple KERNEL_VERSION(a,b,c) macro, which is
unfortunatly in linux/version.h.
There are also lots of #ifdef for long obsolete kernels, this was not
touched. In a few places, the linux/version.h include was move to where
the LINUX_VERSION_CODE was used.
quilt vi `find * -type f -name "*.[ch]"|xargs grep -El '(UTS_RELEASE|LINUX_VERSION_CODE|KERNEL_VERSION|linux/version.h)'|grep -Ev '(/(boot|coda|drm)/|~$)'`
search pattern:
/UTS_RELEASE\|LINUX_VERSION_CODE\|KERNEL_VERSION\|linux\/\(utsname\|version\).h
Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
|
|
Convert everyone who uses platform_bus_type to include
linux/platform_device.h.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
|
|
Patch from Deepak Saxena
OMAP map_desc.pfn conversion
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
|
|
Patch from Tony Lindgren
This patch syncs the mainline kernel with linux-omap tree.
The highlights of the patch are:
- Convert more drivers to register resources in board-*.c to take
advantage of the driver model by David Brownell and Ladislav Michl
- Use set_irq_type() for GPIO interrupts instead of
omap_set_gpio_edge_ctrl() by David Brownell
- Add minimal support for handling optional add-on boards, such as
OSK Mistral board with LCD and keypad, by David Brownell
- Minimal support for loading functions to SRAM by Tony Lindgren
- Wake up from serial port by muxing RX lines temporarily into GPIO
interrupts by Tony Lindgren
- 32KHz sched_clock by Tony Lindgren and Juha Yrjola
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
Rather than hard-coding the platform device IDs, enumerate them.
We don't particularly care about the actual ID we get, just as
long as they're unique.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
Fix the broken initialisers missed by the recent IRQ patch.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
This is part of Thomas Gleixner's generic IRQ patch, which converts
ARM to use the generic IRQ subsystem. Here, we wrap calls to
desc->handler() in an inline function, desc_handle_irq(). This
reduces the size of Thomas' patch since the changes become more
localised.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
Changing CONFIG_LOCALVERSION rebuilds too much, for no appearent reason.
Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
Patch from Tony Lindgren
This patch by various OMAP developers syncs the OMAP
specific arch files with the linux-omap tree.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
Patch from Tony Lindgren
This patch by various OMAP developers syncs the OMAP
specific arch files with the linux-omap tree.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
and serial
Patch from Tony Lindgren
This patch by Juha Yrjölä and other OMAP developers splits
OMAP1 specific common code into OMAP1 id, io, and serial
code in mach-omap1 directory.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
directory
Patch from Tony Lindgren
This patch by Paul Mundt and other OMAP developers
moves OMAP1 board files into mach-omap1 directory.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
directory
Patch from Tony Lindgren
This patch by Paul Mundt and other OMAP developers
moves OMAP1 specific LED code into mach-omap1 directory.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
directory
Patch from Tony Lindgren
This patch by Paul Mundt and other OMAP developers
moves OMAP1 specific IRQ, time, and FPGA code into
mach-omap1 directory.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
and omap2
Patch from Tony Lindgren
This patch by Paul Mundt and other OMAP developers modifies
ARM specific Kconfig to allow sharing code between OMAP1 and
OMAP2 architectures.
In order to share code between OMAP1 and OMAP2, all OMAP1
specific code is moved into mach-omap1 directory in the
following patch. A new mach-omap2 directory will be added
later on.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
