Commit graph

534127 commits

Author SHA1 Message Date
Michal Simek
2221043b75 ARM: dts: zynq: Fix stdout-path and bootargs
parallella - Remove linux,stdout-path.
Use stdout-path to identify kernel console

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
2015-05-28 08:44:56 +02:00
Michal Simek
1b654bc9d4 ARM: dts: zynq: Add missing alias node for zybo and parallella
Add missing alias node.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
2015-05-28 08:13:35 +02:00
Guenter Roeck
e3cb742c32 staging: wilc1000: Disable for S390
The wilc1000 driver uses definitions such as DEBUG_LEVEL, DEBUG,
and PRINT_INFO. This causes compile errors on S390 which has similar
definitions in its core code. Disable the driver for S390 instead
of giving the non-standard messaging code credit by trying to fix it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-27 21:47:16 -07:00
Alexander Duyck
d55c670cbc ip_vti/ip6_vti: Preserve skb->mark after rcv_cb call
The vti6_rcv_cb and vti_rcv_cb calls were leaving the skb->mark modified
after completing the function.  This resulted in the original skb->mark
value being lost.  Since we only need skb->mark to be set for
xfrm_policy_check we can pull the assignment into the rcv_cb calls and then
just restore the original mark after xfrm_policy_check has been completed.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2015-05-28 06:23:32 +02:00
Alexander Duyck
049f8e2e28 xfrm: Override skb->mark with tunnel->parm.i_key in xfrm_input
This change makes it so that if a tunnel is defined we just use the mark
from the tunnel instead of the mark from the skb header.  By doing this we
can avoid the need to set skb->mark inside of the tunnel receive functions.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2015-05-28 06:23:31 +02:00
Alexander Duyck
cd5279c194 ip_vti/ip6_vti: Do not touch skb->mark on xmit
Instead of modifying skb->mark we can simply modify the flowi_mark that is
generated as a result of the xfrm_decode_session.  By doing this we don't
need to actually touch the skb->mark and it can be preserved as it passes
out through the tunnel.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2015-05-28 06:23:31 +02:00
Michel Dänzer
b0b9bb4dd5 drm/radeon: Fix max_vblank_count value for current display engines
The value was much too low, which could cause the userspace visible
vblank counter to move backwards when the hardware counter wrapped
around.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2015-05-28 00:15:30 -04:00
Christian König
161ab658a6 drm/radeon: stop using addr to check for BO move
It is theoretically possible that a swapped out BO gets the
same GTT address, but different backing pages while being swapped in.

Instead just use another VA state to note updated areas.

Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2015-05-28 00:03:39 -04:00
Alex Deucher
0106219361 drm/radeon: clean up radeon_audio_enable
- make it static
- fix mask/bool handling for last param

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
2015-05-28 00:03:39 -04:00
Stephan Mueller
cf58fcb1be crypto: jitterentropy - remove timekeeping_valid_for_hres
The patch removes the use of timekeeping_valid_for_hres which is now
marked as internal for the time keeping subsystem. The jitterentropy
does not really require this verification as a coarse timer (when
random_get_entropy is absent) is discovered by the initialization test
of jent_entropy_init, which would cause the jitter rng to not load in
that case.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:21 +08:00
Herbert Xu
19fa77522e crypto: algif_aead - Switch to new AEAD interface
This patch makes use of the new AEAD interface which uses a single
SG list instead of separate lists for the AD and plain text.

Note that the user-space interface now requires both input and
output to be of the same length, and both must include space for
the AD as well as the authentication tag.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:21 +08:00
Herbert Xu
a3f2185a29 crypto: tcrypt - Switch to new AEAD interface
This patch makes use of the new AEAD interface which uses a single
SG list instead of separate lists for the AD and plain text.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:21 +08:00
Herbert Xu
957e0fe629 mac80211: Switch to new AEAD interface
This patch makes use of the new AEAD interface which uses a single
SG list instead of separate lists for the AD and plain text.

Tested-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:20 +08:00
Herbert Xu
25528fdae4 mac802154: Switch to new AEAD interface
This patch makes use of the new AEAD interface which uses a single
SG list instead of separate lists for the AD and plain text.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:20 +08:00
Herbert Xu
000ae7b269 esp6: Switch to new AEAD interface
This patch makes use of the new AEAD interface which uses a single
SG list instead of separate lists for the AD and plain text.  The
IV generation is also now carried out through normal AEAD methods.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:20 +08:00
Herbert Xu
7021b2e1cd esp4: Switch to new AEAD interface
This patch makes use of the new AEAD interface which uses a single
SG list instead of separate lists for the AD and plain text.  The
IV generation is also now carried out through normal AEAD methods.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:20 +08:00
Herbert Xu
69b0137f61 ipsec: Add IV generator information to xfrm_state
This patch adds IV generator information to xfrm_state.  This
is currently obtained from our own list of algorithm descriptions.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:20 +08:00
Herbert Xu
165ecc6373 xfrm: Add IV generator information to xfrm_algo_desc
This patch adds IV generator information for each AEAD and block
cipher to xfrm_algo_desc.  This will be used to access the new
AEAD interface.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:19 +08:00
Herbert Xu
8a525fcd46 crypto: testmgr - Switch to new AEAD interface
This patch makes use of the new AEAD interface which uses a single
SG list instead of separate lists for the AD and plain text.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:19 +08:00
Herbert Xu
056c04ba8b crypto: seqiv - Fix module unload/reload crash
On module unload we weren't unregistering the seqniv template,
thus leading to a crash the next time someone walks the template
list.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:19 +08:00
Herbert Xu
ccdb8a0384 crypto: seqiv - Fix IV size in context size calculation
This patch fixes a bug in the context size calculation where we
were still referring to the old cra_aead.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:19 +08:00
Herbert Xu
661cfd0e5e crypto: seqiv - Use common IV generation code
This patch makes use of the new common IV generation code.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:18 +08:00
Herbert Xu
d0ad1b246d crypto: seqiv - Copy AD along with plain/cipher text
As the AD does not necessarily exist in the destination buffer
it must be copied along with the plain/cipher text.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:18 +08:00
Herbert Xu
9d03aee125 crypto: echainiv - Fix IV size in context size calculation
This patch fixes a bug in the context size calculation where we
were still referring to the old cra_aead.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:18 +08:00
Herbert Xu
d97de47ca1 crypto: echainiv - Use common IV generation code
This patch makes use of the new common IV generation code.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:18 +08:00
Herbert Xu
838c9d561a crypto: echainiv - Copy AD along with plain text
As the AD does not necessarily exist in the destination buffer
it must be copied along with the plain text.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:18 +08:00
Herbert Xu
6350449fbf crypto: aead - Add common IV generation code
This patch adds some common IV generation code currently duplicated
by seqiv and echainiv.  For example, the setkey and setauthsize
functions are completely identical.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:17 +08:00
Herbert Xu
b455eb80f1 crypto: aead - Preserve in-place processing in old_crypt
This patch tries to preserve in-place processing in old_crypt as
various algorithms are optimised for in-place processing where
src == dst.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:17 +08:00
Herbert Xu
fdaef75f66 crypto: scatterwalk - Add missing sg_init_table to scatterwalk_ffwd
We need to call sg_init_table as otherwise the first entry may
inadvertently become the last.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:17 +08:00
Herbert Xu
693b549d39 crypto: aead - Document behaviour of AD in destination buffer
This patch defines the behaviour of AD in the new interface more
clearly.  In particular, it specifies that if the user must copy
the AD to the destination manually when src != dst if they wish
to guarantee that the destination buffer contains a copy of the
AD.

The reason for this is that otherwise every AEAD implementation
would have to perform such a copy when src != dst.  In reality
most users do in-place processing where src == dst so this is
not an issue.

This patch also kills some remaining references to cryptoff.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-28 11:23:16 +08:00
Herbert Xu
6d7e3d8995 Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Merge the crypto tree for 4.1 to pull in the changeset that disables
algif_aead.
2015-05-28 11:16:41 +08:00
Luis R. Rodriguez
6727bb9c6a kernel/module.c: avoid ifdefs for sig_enforce declaration
There's no need to require an ifdef over the declaration
of sig_enforce as IS_ENABLED() can be used. While at it,
there's no harm in exposing this kernel parameter outside of
CONFIG_MODULE_SIG as it'd be a no-op on non module sig
kernels.

Now, technically we should in theory be able to remove
the #ifdef'ery over the declaration of the module parameter
as we are also trusting the bool_enable_only code for
CONFIG_MODULE_SIG kernels but for now remain paranoid
and keep it.

With time if no one can put a bullet through bool_enable_only
and if there are no technical requirements over not exposing
CONFIG_MODULE_SIG_FORCE with the measures in place by
bool_enable_only we could remove this last ifdef.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: cocci@systeme.lip6.fr
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:13 +09:30
Luis R. Rodriguez
552f530cbc kernel/workqueue.c: remove ifdefs over wq_power_efficient
We can avoid an ifdef over wq_power_efficient's declaration
by just using IS_ENABLED().

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: cocci@systeme.lip6.fr
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:12 +09:30
Luis R. Rodriguez
154be21c58 kernel/params.c: export param_ops_bool_enable_only
This will grant access to this helper to code built as modules.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: David Howells <dhowells@redhat.com>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Kyle McMartin <kyle@kernel.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:12 +09:30
Luis R. Rodriguez
d19f05d8a8 kernel/params.c: generalize bool_enable_only
This takes out the bool_enable_only implementation from
the module loading code and generalizes it so that others
can make use of it.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: cocci@systeme.lip6.fr
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:11 +09:30
Luis R. Rodriguez
05f408dddb kernel/module.c: use generic module param operaters for sig_enforce
We're directly checking and modifying sig_enforce when needed instead
of using the generic helpers. This prevents us from generalizing this
helper so that others can use it. Use indirect helpers to allow us
to generalize this code a bit and to make it a bit more clear what
this is doing.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: cocci@systeme.lip6.fr
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:11 +09:30
Luis R. Rodriguez
9c27847dda kernel/params: constify struct kernel_param_ops uses
Most code already uses consts for the struct kernel_param_ops,
sweep the kernel for the last offending stragglers. Other than
include/linux/moduleparam.h and kernel/params.c all other changes
were generated with the following Coccinelle SmPL patch. Merge
conflicts between trees can be handled with Coccinelle.

In the future git could get Coccinelle merge support to deal with
patch --> fail --> grammar --> Coccinelle --> new patch conflicts
automatically for us on patches where the grammar is available and
the patch is of high confidence. Consider this a feature request.

Test compiled on x86_64 against:

	* allnoconfig
	* allmodconfig
	* allyesconfig

@ const_found @
identifier ops;
@@

const struct kernel_param_ops ops = {
};

@ const_not_found depends on !const_found @
identifier ops;
@@

-struct kernel_param_ops ops = {
+const struct kernel_param_ops ops = {
};

Generated-by: Coccinelle SmPL
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Junio C Hamano <gitster@pobox.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: cocci@systeme.lip6.fr
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:10 +09:30
Gobinda Charan Maji
28b8d0c8f5 sysfs: tightened sysfs permission checks
There were some inconsistency in restriction to VERIFY_OCTAL_PERMISSIONS().
Previously the test was "User perms >= group perms >= other perms". The
permission field of User, Group or Other consists of three bits. LSB is
EXECUTE permission, MSB is READ permission and the middle bit is WRITE
permission. But logically WRITE is "more privileged" than READ.

Say for example, permission value is "0430". Here User has only READ
permission whereas Group has both WRITE and EXECUTE permission.

So, the checks could be tightened and the tests are separated to
USER_READABLE >= GROUP_READABLE >= OTHER_READABLE,
USER_WRITABLE >= GROUP_WRITABLE and OTHER_WRITABLE is not permitted.

Signed-off-by: Gobinda Charan Maji <gobinda.cemk07@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:09 +09:30
Peter Zijlstra
4f666546d0 module: Rework module_addr_{min,max}
__module_address() does an initial bound check before doing the
{list/tree} iteration to find the actual module. The bound variables
are nowhere near the mod_tree cacheline, in fact they're nowhere near
one another.

module_addr_min lives in .data while module_addr_max lives in .bss
(smarty pants GCC thinks the explicit 0 assignment is a mistake).

Rectify this by moving the two variables into a structure together
with the latch_tree_root to guarantee they all share the same
cacheline and avoid hitting two extra cachelines for the lookup.

While reworking the bounds code, move the bound update from allocation
to insertion time, this avoids updating the bounds for a few error
paths.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:09 +09:30
Peter Zijlstra
b7df4d1b23 module: Use __module_address() for module_address_lookup()
Use the generic __module_address() addr to struct module lookup
instead of open coding it once more.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:08 +09:30
Peter Zijlstra
6c9692e2d6 module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACING
Andrew worried about the overhead on small systems; only use the fancy
code when either perf or tracing is enabled.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Requested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:07 +09:30
Peter Zijlstra
93c2e105f6 module: Optimize __module_address() using a latched RB-tree
Currently __module_address() is using a linear search through all
modules in order to find the module corresponding to the provided
address. With a lot of modules this can take a lot of time.

One of the users of this is kernel_text_address() which is employed
in many stack unwinders; which in turn are used by perf-callchain and
ftrace (possibly from NMI context).

So by optimizing __module_address() we optimize many stack unwinders
which are used by both perf and tracing in performance sensitive code.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:07 +09:30
Peter Zijlstra
ade3f510f9 rbtree: Implement generic latch_tree
Implement a latched RB-tree in order to get unconditional RCU/lockless
lookups.

Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:06 +09:30
Peter Zijlstra
7fc26327b7 seqlock: Introduce raw_read_seqcount_latch()
Because with latches there is a strict data dependency on the seq load
we can avoid the rmb in favour of a read_barrier_depends.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:06 +09:30
Peter Zijlstra
0a04b01669 rcu: Move lockless_dereference() out of rcupdate.h
I want to use lockless_dereference() from seqlock.h, which would mean
including rcupdate.h from it, however rcupdate.h already includes
seqlock.h.

Avoid this by moving lockless_dereference() into compiler.h. This is
somewhat tricky since it uses smp_read_barrier_depends() which isn't
available there, but its a CPP macro so we can get away with it.

The alternative would be moving it into asm/barrier.h, but that would
be updating each arch (I can do if people feel that is more
appropriate).

Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:05 +09:30
Peter Zijlstra
6695b92a60 seqlock: Better document raw_write_seqcount_latch()
Improve the documentation of the latch technique as used in the
current timekeeping code, such that it can be readily employed
elsewhere.

Borrow from the comments in timekeeping and replace those with a
reference to this more generic comment.

Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:04 +09:30
Peter Zijlstra
d72da4a4d9 rbtree: Make lockless searches non-fatal
Change the insert and erase code such that lockless searches are
non-fatal.

In and of itself an rbtree cannot be correctly searched while
in-modification, we can however provide weaker guarantees that will
allow the rbtree to be used in conjunction with other techniques, such
as latches; see 9b0fd802e8 ("seqcount: Add raw_write_seqcount_latch()").

For this to work we need the following guarantees from the rbtree
code:

 1) a lockless reader must not see partial stores, this would allow it
    to observe nodes that are invalid memory.

 2) there must not be (temporary) loops in the tree structure in the
    modifier's program order, this would cause a lookup which
    interrupts the modifier to get stuck indefinitely.

For 1) we must use WRITE_ONCE() for all updates to the tree structure;
in particular this patch only does rb_{left,right} as those are the
only element required for simple searches.

It generates slightly worse code, probably because volatile. But in
pointer chasing heavy code a few instructions more should not matter.

For 2) I have carefully audited the code and drawn every intermediate
link state and not found a loop.

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Reviewed-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:04 +09:30
Peter Zijlstra
0be964be0d module: Sanitize RCU usage and locking
Currently the RCU usage in module is an inconsistent mess of RCU and
RCU-sched, this is broken for CONFIG_PREEMPT where synchronize_rcu()
does not imply synchronize_sched().

Most usage sites use preempt_{dis,en}able() which is RCU-sched, but
(most of) the modification sites use synchronize_rcu(). With the
exception of the module bug list, which actually uses RCU.

Convert everything over to RCU-sched.

Furthermore add lockdep asserts to all sites, because it's not at all
clear to me the required locking is observed, esp. on exported
functions.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:31:52 +09:30
NeilBrown
626f2092c8 md/raid5: break stripe-batches when the array has failed.
Once the array has too much failure, we need to break
stripe-batches up so they can all be dealt with.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-05-28 11:48:59 +10:00
NeilBrown
787b76fa37 md/raid5: call break_stripe_batch_list from handle_stripe_clean_event
Now that the code in break_stripe_batch_list() is nearly identical
to the end of handle_stripe_clean_event, replace the later
with a function call.

The only remaining difference of any interest is the masking that is
applieds to dev[i].flags copied from head_sh.
R5_WriteError certainly isn't wanted as it is set per-stripe, not
per-patch.  R5_Overlap isn't wanted as it is explicitly handled.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-05-28 11:47:02 +10:00