Problem: it's hard to avoid an init routine stumbling over a
request_module these days. And it's not clear it's always a bad idea:
for example, a module like kvm with dynamic dependencies on kvm-intel
or kvm-amd would be neater if it could simply request_module the right
one.
In this particular case, it's libcrc32c:
libcrc32c_mod_init
crypto_alloc_shash
crypto_alloc_tfm
crypto_find_alg
crypto_alg_mod_lookup
crypto_larval_lookup
request_module
If another module is waiting inside resolve_symbol() for libcrc32c to
finish initializing (ie. bne2 depends on libcrc32c) then it does so
holding the module lock, and our request_module() can't make progress
until that is released.
Waiting inside resolve_symbol() without the lock isn't all that hard:
we just need to pass the -EBUSY up the call chain so we can sleep
where we don't hold the lock. Error reporting is a bit trickier: we
need to copy the name of the unfinished module before releasing the
lock.
Other notes:
1) This also fixes a theoretical issue where a weak dependency would allow
symbol version mismatches to be ignored.
2) We rename use_module to ref_module to make life easier for the only
external user (the out-of-tree ksplice patches).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tim Abbot <tabbott@ksplice.com>
Tested-by: Brandon Philips <bphilips@suse.de>
It disabled preempt so it was "safe", but nothing stops another module
slipping in before this module is added to the global list now we don't
hold the lock the whole time.
So we check this just after we check for duplicate modules, and just
before we put the module in the global list.
(find_symbol finds symbols in coming and going modules, too).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I think Rusty may have made the lock a bit _too_ finegrained there, and
didn't add it to some places that needed it. It looks, for example, like
PATCH 1/2 actually drops the lock in places where it's needed
("find_module()" is documented to need it, but now load_module() didn't
hold it at all when it did the find_module()).
Rather than adding a new "module_loading" list, I think we should be able
to just use the existing "modules" list, and just fix up the locking a
bit.
In fact, maybe we could just move the "look up existing module" a bit
later - optimistically assuming that the module doesn't exist, and then
just undoing the work if it turns out that we were wrong, just before
adding ourselves to the list.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Kay Sievers <kay.sievers@vrfy.org> reports that we still have some
contention over module loading which is slowing boot.
Linus also disliked a previous "drop lock and regrab" patch to fix the
bne2 "gave up waiting for init of module libcrc32c" message.
This is more ambitious: we only grab the lock where we need it.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Brandon Philips <brandon@ifup.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
These were placed in the header in ef665c1a06 to get the various
SYSFS/MODULE config combintations to compile.
That may have been necessary then, but it's not now. These functions
are all local to module.c.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
This means a little extra work, but is more logical: we don't put
anything in sysfs until we're about to put the module into the
global list an parse its parameters.
This also gives us a logical place to put duplicate module detection
in the next patch.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Linus changed the structure, and luckily this didn't compile any more.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Martin Hicks <mort@sgi.com>
When adding a module that depends on another one, we used to create a
one-way list of "modules_which_use_me", so that module unloading could
see who needs a module.
It's actually quite simple to make that list go both ways: so that we
not only can see "who uses me", but also see a list of modules that are
"used by me".
In fact, we always wanted that list in "module_unload_free()": when we
unload a module, we want to also release all the other modules that are
used by that module. But because we didn't have that list, we used to
first iterate over all modules, and then iterate over each "used by me"
list of that module.
By making the list two-way, we simplify module_unload_free(), and it
allows for some trivial fixes later too.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (cleaned & rebased)
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
libata: implement on-demand HPA unlocking
libata: use the enlarged capacity after late HPA unlock
SCSI: implement sd_unlock_native_capacity()
libata-sff: trivial corrections to Kconfig help text
sata_nv: don't diddle with nIEN on mcp55
sata_via: magic vt6421 fix for transmission problems w/ WD drives
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched, trace: Fix sched_switch() prev_state argument
sched: Fix wake_affine() vs RT tasks
sched: Make sure timers have migrated before killing the migration_thread
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, smpboot: Fix cores per node printing on boot
x86/amd-iommu: Fall back to GART if initialization fails
x86/amd-iommu: Fix crash when request_mem_region fails
x86/mm: Remove unused DBG() macro
arch/x86/kernel: Add missing spin_unlock
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc/macio: Fix probing of macio devices by using the right of match table
agp/uninorth: Fix oops caused by flushing too much
powerpc/pasemi: Update MAINTAINERS file
powerpc/cell: Fix integer constant warning
powerpc/kprobes: Remove resume_execution() in kprobes
powerpc/macio: Don't dereference pointer before null check
* 'for-linus/bugfixes' of git://xenbits.xensource.com/people/ianc/linux-2.6:
xen: avoid allocation causing potential swap activity on the resume path
xen: ensure timer tick is resumed even on CPU driving the resume
* 'perf-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf: Fix crash in swevents
perf buildid-list: Fix --with-hits event processing
perf scripts python: Give field dict to unhandled callback
perf hist: fix objdump output parsing
perf-record: Check correct pid when forking
perf: Do the comm inheritance per thread in event__process_task
perf: Use event__process_task from perf sched
perf: Process comm events by tid
blktrace: Fix new kernel-doc warnings
perf_events: Fix unincremented buffer base on partial copy
perf_events: Fix event scheduling issues introduced by transactional API
perf_events, trace: Fix perf_trace_destroy(), mutex went missing
perf_events, trace: Fix probe unregister race
perf_events: Fix races in group composition
perf_events: Fix races and clean up perf_event and perf_mmap_data interaction
* 'virtio' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
virtio: console: Fix crash when port is unplugged and blocked for write
virtio: console: Fix crash when hot-unplugging a port and read is blocked
virtio-blk: fix minimum number of S/G elements
Frederic reported that because swevents handling doesn't disable IRQs
anymore, we can get a recursion of perf_adjust_period(), once from
overflow handling and once from the tick.
If both call ->disable, we get a double hlist_del_rcu() and trigger
a LIST_POISON2 dereference.
Since we don't actually need to stop/start a swevent to re-programm
the hardware (lack of hardware to program), simply nop out these
callbacks for the swevent pmu.
Reported-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1275557609.27810.35218.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (41 commits)
drm/radeon/kms: make sure display hw is disabled when suspending
drm/vmwgfx: Allow userspace to change default layout. Bump minor.
drm/vmwgfx: Fix framebuffer modesetting
drm/vmwgfx: Fix vga save / restore with display topology.
vgaarb: use MIT license
vgaarb: convert pr_devel() to pr_debug()
drm: fix typos in Linux DRM Developer's Guide
drm/radeon/kms/pm: voltage fixes
drm/radeon/kms/pm: radeon_set_power_state fixes
drm/radeon/kms/pm: patch default power state with default clocks/voltages on r6xx+
drm/radeon/kms/pm: enable SetVoltage on r7xx/evergreen
drm/radeon/kms/pm: add support for SetVoltage cmd table (V2)
drm/radeon/kms/evergreen: add initial CS parser
drm/kms: disable/enable poll around switcheroo on/off
drm/nouveau: fixup confusion over which handle the DSM is hanging off.
drm/nouveau: attempt to get bios from ACPI v3
drm/nv50: cast IGP memory location to u64 before shifting
drm/ttm: Fix ttm_page_alloc.c
drm/ttm: Fix cached TTM page allocation.
drm/vmwgfx: Remove some leftover debug messages.
...
When a program that has a virtio port opened and blocked for a write
operation, a port hot-unplug event will later led to a crash when
SIGTERM was sent to the program. Fix that.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When removing a port we don't check if a program was blocked for read.
This leads to a crash when SIGTERM is sent to the program after
hot-unplugging the port.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We need at least one S/G element to operate properly, as does the block
layer which increments it to one anyway. We hit this due to a qemu
bug which advertises a sg_elements of 0 under some circumstances.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (tweaked logic)
I2C drivers can use the clientdata-pointer to point to private data. As I2C
devices are not really unregistered, but merely detached from their driver, it
used to be the drivers obligation to clear this pointer during remove() or a
failed probe(). As a couple of drivers forgot to do this, it was agreed that it
was cleaner if the i2c-core does this clearance when appropriate, as there is
no guarantee for the lifetime of the clientdata-pointer after remove() anyhow.
This feature was added to the core with commit
e4a7b9b04d to fix the faulty drivers.
As there is no need anymore to clear the clientdata-pointer, remove all current
occurrences in the drivers to simplify the code and prevent confusion.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Richard Purdie <rpurdie@linux.intel.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Move strict I2C address validity check to a single function, and
document the reserved I2C addresses there.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Hans Verkuil <hverkuil@xs4all.nl>
Do basic address validity checks when a client is being registered. We
already had checks in place for devices which are being detected, but
not for devices which are simply instantiated.
This is a very basic check. We don't want to do strict checking here
because some devices are known to infringe the I2C address constraints
(e.g. IR receivers at 7-bit address 0x7a while this value is
supposedly reserved for 10-bit addresses.) So we assume the caller
knows what it is doing.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Matthieu Castet <castet.matthieu@free.fr>
Use the same I2C device presence detection code for legacy and new
device detection functions. This is more consistent and makes the code
smaller.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Matthieu Castet <castet.matthieu@free.fr>
Remove all trailing whitespace in Documentation/i2c.
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Since the device we are resuming could be the device containing the
swap device we should ensure that the allocation cannot cause
IO.
On resume, this path is triggered when the running system tries to
continue using its devices. If it cannot then the resume will fail;
to try to avoid this we let it dip into the emergency pools.
The majority of these changes were made when linux-2.6.18-xen.hg
changeset e8b49cfbdac0 was ported upstream in
a144ff09bc but somehow this hunk was
dropped.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Stable Kernel <stable@kernel.org> # .32.x
The core suspend/resume code is run from stop_machine on CPU0 but
parts of the suspend/resume machinery (including xen_arch_resume) are
run on whichever CPU happened to schedule the xenwatch kernel thread.
As part of the non-core resume code xen_arch_resume is called in order
to restart the timer tick on non-boot processors. The boot processor
itself is taken care of by core timekeeping code.
xen_arch_resume uses smp_call_function which does not call the given
function on the current processor. This means that we can end up with
one CPU not receiving timer ticks if the xenwatch thread happened to
be scheduled on CPU > 0.
Use on_each_cpu instead of smp_call_function to ensure the timer tick
is resumed everywhere.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Stable Kernel <stable@kernel.org> # .32.x
Fixes build error caused by the OF device_node
pointer being moved into struct device
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Disable the display hw when suspending.
Should fix bug:
https://bugzilla.redhat.com/show_bug.cgi?id=522393
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
The host may change the layout and, since the change is
communicated to the master, the master needs a way to
communicate the change to the kernel driver.
The minor version number is bumped to advertize the
availability of this feature.
Signed-off-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Must set SVGA_NUM_REG_GUEST_DISPLAY before setting up the display information.
Signed-off-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
vga save / restore previously didn't handle the display topology case.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
We want to be able to use CONFIG_DYNAMIC_DEBUG in arbiter code, switch
the few existing pr_devel() calls to pr_debug().
Also, add one more debug information regarding decoding count.
Signed-off-by: Tiago Vignatti <tiago.vignatti@nokia.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
A few typos in the DRM Developer's Guide.
Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Acked-by: Jesse Barnes <jesse.barnes@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
- Enable GPIO voltage for non pm modes as well so resetting
the default voltage works.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
- wait for vbl for both profile and dynpm
- unify profile and dynpm code paths more
- call pm_misc before of after clocks to make
sure voltage is changed in the proper order.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
The default power state does not always match the default clocks and voltage
for a particular card. The information in the firmware info table is correct
and should be used in preference to the info the default power state.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
- This enables voltage adjustment on r6xx+ and certain
r5xx asics.
- Voltage drop support is already available for most
r1xx-r5xx asics.
V2: endian fix for voltage table.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Fixes build error caused by the OF device_node
pointer being moved into struct device
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Fixes build errors in EDAC drivers caused by the OF
device_node pointer being moved into struct device
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Fixes build error caused by the OF device_node
pointer being moved into struct device
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
