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693,635 commits

Author SHA1 Message Date
Eric Biggers
63a0b0509e KEYS: fix freeing uninitialized memory in key_update()
key_update() freed the key_preparsed_payload even if it was not
initialized first.  This would cause a crash if userspace called
keyctl_update() on a key with type like "asymmetric" that has a
->preparse() method but not an ->update() method.  Possibly it could
even be triggered for other key types by racing with keyctl_setperm() to
make the KEY_NEED_WRITE check fail (the permission was already checked,
so normally it wouldn't fail there).

Reproducer with key type "asymmetric", given a valid cert.der:

keyctl new_session
keyid=$(keyctl padd asymmetric desc @s < cert.der)
keyctl setperm $keyid 0x3f000000
keyctl update $keyid data

[  150.686666] BUG: unable to handle kernel NULL pointer dereference at 0000000000000001
[  150.687601] IP: asymmetric_key_free_kids+0x12/0x30
[  150.688139] PGD 38a3d067
[  150.688141] PUD 3b3de067
[  150.688447] PMD 0
[  150.688745]
[  150.689160] Oops: 0000 [#1] SMP
[  150.689455] Modules linked in:
[  150.689769] CPU: 1 PID: 2478 Comm: keyctl Not tainted 4.11.0-rc4-xfstests-00187-ga9f6b6b8cd2f #742
[  150.690916] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-20170228_101828-anatol 04/01/2014
[  150.692199] task: ffff88003b30c480 task.stack: ffffc90000350000
[  150.692952] RIP: 0010:asymmetric_key_free_kids+0x12/0x30
[  150.693556] RSP: 0018:ffffc90000353e58 EFLAGS: 00010202
[  150.694142] RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000004
[  150.694845] RDX: ffffffff81ee3920 RSI: ffff88003d4b0700 RDI: 0000000000000001
[  150.697569] RBP: ffffc90000353e60 R08: ffff88003d5d2140 R09: 0000000000000000
[  150.702483] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
[  150.707393] R13: 0000000000000004 R14: ffff880038a4d2d8 R15: 000000000040411f
[  150.709720] FS:  00007fcbcee35700(0000) GS:ffff88003fd00000(0000) knlGS:0000000000000000
[  150.711504] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  150.712733] CR2: 0000000000000001 CR3: 0000000039eab000 CR4: 00000000003406e0
[  150.714487] Call Trace:
[  150.714975]  asymmetric_key_free_preparse+0x2f/0x40
[  150.715907]  key_update+0xf7/0x140
[  150.716560]  ? key_default_cmp+0x20/0x20
[  150.717319]  keyctl_update_key+0xb0/0xe0
[  150.718066]  SyS_keyctl+0x109/0x130
[  150.718663]  entry_SYSCALL_64_fastpath+0x1f/0xc2
[  150.719440] RIP: 0033:0x7fcbce75ff19
[  150.719926] RSP: 002b:00007ffd5d167088 EFLAGS: 00000206 ORIG_RAX: 00000000000000fa
[  150.720918] RAX: ffffffffffffffda RBX: 0000000000404d80 RCX: 00007fcbce75ff19
[  150.721874] RDX: 00007ffd5d16785e RSI: 000000002866cd36 RDI: 0000000000000002
[  150.722827] RBP: 0000000000000006 R08: 000000002866cd36 R09: 00007ffd5d16785e
[  150.723781] R10: 0000000000000004 R11: 0000000000000206 R12: 0000000000404d80
[  150.724650] R13: 00007ffd5d16784d R14: 00007ffd5d167238 R15: 000000000040411f
[  150.725447] Code: 83 c4 08 31 c0 5b 41 5c 41 5d 41 5e 41 5f 5d c3 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 85 ff 74 23 55 48 89 e5 53 48 89 fb <48> 8b 3f e8 06 21 c5 ff 48 8b 7b 08 e8 fd 20 c5 ff 48 89 df e8
[  150.727489] RIP: asymmetric_key_free_kids+0x12/0x30 RSP: ffffc90000353e58
[  150.728117] CR2: 0000000000000001
[  150.728430] ---[ end trace f7f8fe1da2d5ae8d ]---

Fixes: 4d8c0250b8 ("KEYS: Call ->free_preparse() even after ->preparse() returns an error")
Cc: stable@vger.kernel.org # 3.17+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:47 +10:00
Eric Biggers
5649645d72 KEYS: fix dereferencing NULL payload with nonzero length
sys_add_key() and the KEYCTL_UPDATE operation of sys_keyctl() allowed a
NULL payload with nonzero length to be passed to the key type's
->preparse(), ->instantiate(), and/or ->update() methods.  Various key
types including asymmetric, cifs.idmap, cifs.spnego, and pkcs7_test did
not handle this case, allowing an unprivileged user to trivially cause a
NULL pointer dereference (kernel oops) if one of these key types was
present.  Fix it by doing the copy_from_user() when 'plen' is nonzero
rather than when '_payload' is non-NULL, causing the syscall to fail
with EFAULT as expected when an invalid buffer is specified.

Cc: stable@vger.kernel.org # 2.6.10+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:47 +10:00
Eric Biggers
0f534e4a13 KEYS: encrypted: use constant-time HMAC comparison
MACs should, in general, be compared using crypto_memneq() to prevent
timing attacks.

Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:47 +10:00
Eric Biggers
64d107d3ac KEYS: encrypted: fix race causing incorrect HMAC calculations
The encrypted-keys module was using a single global HMAC transform,
which could be rekeyed by multiple threads concurrently operating on
different keys, causing incorrect HMAC values to be calculated.  Fix
this by allocating a new HMAC transform whenever we need to calculate a
HMAC.  Also simplify things a bit by allocating the shash_desc's using
SHASH_DESC_ON_STACK() for both the HMAC and unkeyed hashes.

The following script reproduces the bug:

    keyctl new_session
    keyctl add user master "abcdefghijklmnop" @s
    for i in $(seq 2); do
        (
            set -e
            for j in $(seq 1000); do
                keyid=$(keyctl add encrypted desc$i "new user:master 25" @s)
                datablob="$(keyctl pipe $keyid)"
                keyctl unlink $keyid > /dev/null
                keyid=$(keyctl add encrypted desc$i "load $datablob" @s)
                keyctl unlink $keyid > /dev/null
            done
        ) &
    done

Output with bug:

    [  439.691094] encrypted_key: bad hmac (-22)
    add_key: Invalid argument
    add_key: Invalid argument

Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:47 +10:00
Eric Biggers
794b4bc292 KEYS: encrypted: fix buffer overread in valid_master_desc()
With the 'encrypted' key type it was possible for userspace to provide a
data blob ending with a master key description shorter than expected,
e.g. 'keyctl add encrypted desc "new x" @s'.  When validating such a
master key description, validate_master_desc() could read beyond the end
of the buffer.  Fix this by using strncmp() instead of memcmp().  [Also
clean up the code to deduplicate some logic.]

Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:46 +10:00
Eric Biggers
e9ff56ac35 KEYS: encrypted: avoid encrypting/decrypting stack buffers
Since v4.9, the crypto API cannot (normally) be used to encrypt/decrypt
stack buffers because the stack may be virtually mapped.  Fix this for
the padding buffers in encrypted-keys by using ZERO_PAGE for the
encryption padding and by allocating a temporary heap buffer for the
decryption padding.

Tested with CONFIG_DEBUG_SG=y:
	keyctl new_session
	keyctl add user master "abcdefghijklmnop" @s
	keyid=$(keyctl add encrypted desc "new user:master 25" @s)
	datablob="$(keyctl pipe $keyid)"
	keyctl unlink $keyid
	keyid=$(keyctl add encrypted desc "load $datablob" @s)
	datablob2="$(keyctl pipe $keyid)"
	[ "$datablob" = "$datablob2" ] && echo "Success!"

Cc: Andy Lutomirski <luto@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 4.9+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:46 +10:00
Eric Biggers
d636bd9f12 KEYS: put keyring if install_session_keyring_to_cred() fails
In join_session_keyring(), if install_session_keyring_to_cred() were to
fail, we would leak the keyring reference, just like in the bug fixed by
commit 23567fd052 ("KEYS: Fix keyring ref leak in
join_session_keyring()").  Fortunately this cannot happen currently, but
we really should be more careful.  Do this by adding and using a new
error label at which the keyring reference is dropped.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:46 +10:00
Markus Elfring
41f1c53e0d KEYS: Delete an error message for a failed memory allocation in get_derived_key()
Omit an extra message for a memory allocation failure in this function.

This issue was detected by using the Coccinelle software.

Link: http://events.linuxfoundation.org/sites/events/files/slides/LCJ16-Refactor_Strings-WSang_0.pdf
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:46 +10:00
Dan Carpenter
4e880168e9 X.509: Fix error code in x509_cert_parse()
We forgot to set the error code on this path so it could result in
returning NULL which leads to a NULL dereference.

Fixes: db6c43bd21 ("crypto: KEYS: convert public key and digsig asym to the akcipher api")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:45 +10:00
Davidlohr Bueso
381f20fceb security: use READ_ONCE instead of deprecated ACCESS_ONCE
With the new standardized functions, we can replace all ACCESS_ONCE()
calls across relevant security/keyrings/.

ACCESS_ONCE() does not work reliably on non-scalar types. For example
gcc 4.6 and 4.7 might remove the volatile tag for such accesses during
the SRA (scalar replacement of aggregates) step:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145

Update the new calls regardless of if it is a scalar type, this is
cleaner than having three alternatives.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:45 +10:00
Bilal Amarni
47b2c3fff4 security/keys: add CONFIG_KEYS_COMPAT to Kconfig
CONFIG_KEYS_COMPAT is defined in arch-specific Kconfigs and is missing for
several 64-bit architectures : mips, parisc, tile.

At the moment and for those architectures, calling in 32-bit userspace the
keyctl syscall would return an ENOSYS error.

This patch moves the CONFIG_KEYS_COMPAT option to security/keys/Kconfig, to
make sure the compatibility wrapper is registered by default for any 64-bit
architecture as long as it is configured with CONFIG_COMPAT.

[DH: Modified to remove arm64 compat enablement also as requested by Eric
 Biggers]

Signed-off-by: Bilal Amarni <bilal.amarni@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
cc: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:45 +10:00
Dave Airlie
6e88007e22 Merge branch 'vmwgfx-fixes-4.12' of git://people.freedesktop.org/~thomash/linux into drm-fixes
A bunch of fixes for vmwgfx 4.12 regressions and older stuff. In the latter
case either trivial, cc'd stable or requiring backports for stable.

* 'vmwgfx-fixes-4.12' of git://people.freedesktop.org/~thomash/linux:
  drm/vmwgfx: Bump driver minor and date
  drm/vmwgfx: Remove unused legacy cursor functions
  drm/vmwgfx: fix spelling mistake "exeeds" -> "exceeds"
  drm/vmwgfx: Fix large topology crash
  drm/vmwgfx: Make sure to update STDU when FB is updated
  drm/vmwgfx: Make sure backup_handle is always valid
  drm/vmwgfx: Handle vmalloc() failure in vmw_local_fifo_reserve()
  drm/vmwgfx: Don't create proxy surface for cursor
  drm/vmwgfx: limit the number of mip levels in vmw_gb_surface_define_ioctl()
2017-06-09 13:12:02 +10:00
Dave Airlie
3d76917f50 Merge tag 'drm-intel-fixes-2017-06-08' of git://anongit.freedesktop.org/git/drm-intel into drm-fixes
drm/i915 fixes for v4.12-rc5

* tag 'drm-intel-fixes-2017-06-08' of git://anongit.freedesktop.org/git/drm-intel:
  drm/i915: fix warning for unused variable
  drm/i915: Fix 90/270 rotated coordinates for FBC
  drm/i915: Restore has_fbc=1 for ILK-M
  drm/i915: Workaround VLV/CHV DSI scanline counter hardware fail
  drm/i915: Fix logical inversion for gen4 quirking
  drm/i915: Guard against i915_ggtt_disable_guc() being invoked unconditionally
  drm/i915: Always recompute watermarks when distrust_bios_wm is set, v2.
  drm/i915: Prevent the system suspend complete optimization
  drm/i915/psr: disable psr2 for resolution greater than 32X20
  drm/i915: Hold a wakeref for probing the ring registers
  drm/i915: Short-circuit i915_gem_wait_for_idle() if already idle
  drm/i915: Disable decoupled MMIO
  drm/i915/guc: Remove stale comment for q_fail
  drm/i915: Serialize GTT/Aperture accesses on BXT
2017-06-09 12:18:07 +10:00
Dave Airlie
b62dba5577 Merge tag 'drm-misc-fixes-2017-06-07' of git://anongit.freedesktop.org/git/drm-misc into drm-fixes
Driver Changes:
- kirin: Use correct dt port for the bridge (John)
- meson: Fix regression caused by adding HDMI support to allow board
	 configurations without HDMI (Neil)

Cc: John Stultz <john.stultz@linaro.org>
Cc: Neil Armstrong <narmstrong@baylibre.com>

* tag 'drm-misc-fixes-2017-06-07' of git://anongit.freedesktop.org/git/drm-misc:
  drm/meson: Fix driver bind when only CVBS is available
  drm: kirin: Fix drm_of_find_panel_or_bridge conversion
2017-06-09 12:17:27 +10:00
Dave Airlie
97f607fe0d Merge branch 'mediatek-drm-fixes-4.12-rc1' of https://github.com/ckhu-mediatek/linux.git-tags into drm-fixes
mediatek fixes

* 'mediatek-drm-fixes-4.12-rc1' of https://github.com/ckhu-mediatek/linux.git-tags:
  drm/mediatek: fix mtk_hdmi_setup_vendor_specific_infoframe mistake
  drm/mediatek: fix a timeout loop
2017-06-09 12:17:00 +10:00
Dave Airlie
dd44c95739 imx-drm: PRE clock gating, panelless LDB, and VDIC CSI selection fixes
- Keep the external clock input to the PRE ungated and only use the internal
   soft reset to keep the module in low power state, to avoid sporadic startup
   failures.
 - Ignore -ENODEV return values from drm_of_find_panel_or_bridge in the LDB
   driver to fix probing for devices that still do not specify a panel in the
   device tree.
 - Fix the CSI input selection to the VDIC. According to experiments, the real
   behaviour differs a bit from the documentation.
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Merge tag 'imx-drm-fixes-2017-06-08' of git://git.pengutronix.de/git/pza/linux into drm-fixes

imx-drm: PRE clock gating, panelless LDB, and VDIC CSI selection fixes

- Keep the external clock input to the PRE ungated and only use the internal
  soft reset to keep the module in low power state, to avoid sporadic startup
  failures.
- Ignore -ENODEV return values from drm_of_find_panel_or_bridge in the LDB
  driver to fix probing for devices that still do not specify a panel in the
  device tree.
- Fix the CSI input selection to the VDIC. According to experiments, the real
  behaviour differs a bit from the documentation.

* tag 'imx-drm-fixes-2017-06-08' of git://git.pengutronix.de/git/pza/linux:
  gpu: ipu-v3: Fix CSI selection for VDIC
  drm/imx: imx-ldb: Accept drm_of_find_panel_or_bridge failure
  gpu: ipu-v3: pre: only use internal clock gating
2017-06-09 12:16:25 +10:00
Paul E. McKenney
6d48152eaf rcu: Remove RCU CPU stall warnings from Tiny RCU
Tiny RCU's job is to be tiny, so this commit removes its RCU CPU
stall warning code.  After this, there is no longer any need for
rcu_sched_ctrlblk and rcu_bh_ctrlblk to be in tiny_plugin.h, so this
commit also moves them to tiny.c.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:45 -07:00
Paul E. McKenney
c23484f0e7 rcu: Remove event tracing from Tiny RCU
This commit saves a few lines by getting rid of Tiny RCU's event tracing.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:45 -07:00
Paul E. McKenney
43a0a2a7d7 rcu: Move RCU debug Kconfig options to kernel/rcu
RCU's debugging Kconfig options are in the unintuitive location
lib/Kconfig.debug, and there are enough of them that it would be good for
them to be more centralized.  This commit therefore extracts RCU's Kconfig
options from init/Kconfig into a new kernel/rcu/Kconfig.debug file.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:44 -07:00
Paul E. McKenney
0af92d4609 rcu: Move RCU non-debug Kconfig options to kernel/rcu
RCU's Kconfig options are scattered, and there are enough of them
that it would be good for them to be more centralized.  This commit
therefore extracts RCU's Kconfig options from init/Kconfig into a new
kernel/rcu/Kconfig file.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:44 -07:00
Paul E. McKenney
44c65ff2e3 rcu: Eliminate NOCBs CPU-state Kconfig options
The CONFIG_RCU_NOCB_CPU_ALL, CONFIG_RCU_NOCB_CPU_NONE, and
CONFIG_RCU_NOCB_CPU_ZERO Kconfig options are used only in testing and
are redundant with the rcu_nocbs= boot parameter.  This commit therefore
removes these three Kconfig options and adjusts the rcutorture scripts
to use the boot parameter instead.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:43 -07:00
Paul E. McKenney
ae91aa0adb rcu: Remove debugfs tracing
RCU's debugfs tracing used to be the only reasonable low-level debug
information available, but ftrace and event tracing has since surpassed
the RCU debugfs level of usefulness.  This commit therefore removes
RCU's debugfs tracing.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:43 -07:00
Paul E. McKenney
bd8cc5a062 srcu: Remove Classic SRCU
Classic SRCU was only ever intended to be a fallback in case of issues
with Tree/Tiny SRCU, and the latter two are doing quite well in testing.
This commit therefore removes Classic SRCU.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:42 -07:00
Paul E. McKenney
7f0cd63330 srcu: Fix rcutorture-statistics typo
The function srcutorture_get_gp_data() duplicated the check for
sp->batch_check0.head instead of also checking sp->batch_check1.head.
The only effect of this typo would be for rcutorture statistics to
understate the fraction of time that an SRCU grace period was in flight,
and only for Classic SRCU.  This commit fixes this typo.

Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:42 -07:00
Paul E. McKenney
41a2901e7d rcu: Remove SPARSE_RCU_POINTER Kconfig option
The sparse-based checking for non-RCU accesses to RCU-protected pointers
has been around for a very long time, and it is now the only type of
sparse-based checking that is optional.  This commit therefore makes
it unconditional.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
2017-06-08 18:52:41 -07:00
Paul E. McKenney
c4a09ff752 rcu: Remove the now-obsolete PROVE_RCU_REPEATEDLY Kconfig option
The PROVE_RCU_REPEATEDLY Kconfig option was initially added due to
the volume of messages from PROVE_RCU: Doing just one per boot would
have required excessive numbers of boots to locate them all.  However,
PROVE_RCU messages are now relatively rare, so there is no longer any
reason to need more than one such message per boot.  This commit therefore
removes the PROVE_RCU_REPEATEDLY Kconfig option.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
2017-06-08 18:52:41 -07:00
Paul E. McKenney
4e4bea7427 rcu: Remove typecheck() from RCU locking wrapper functions
Because raw_spin_lock_irqsave() and raw_spin_unlock_irqrestore()
both do typecheck() on their flags argument, there is no point in
duplicating this check in raw_spin_lock_irqsave_rcu_node() and
raw_spin_unlock_irqrestore_rcu_node().  This commit therefore saves
a few lines by removing this duplicated check.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:40 -07:00
Paul E. McKenney
d2b1654f91 rcu: Remove #ifdef moving rcu_end_inkernel_boot from rcupdate.h
This commit removes a #ifdef and saves a few lines of code by moving
the rcu_end_inkernel_boot() function from include/linux/rcupdate.h to
include/linux/rcutiny.h (for TINY_RCU) and to include/linux/rcutree.h
(for TREE_RCU).

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:40 -07:00
Paul E. McKenney
fe5ac724d8 rcu: Remove nohz_full full-system-idle state machine
The NO_HZ_FULL_SYSIDLE full-system-idle capability was added in 2013
by commit 0edd1b1784 ("nohz_full: Add full-system-idle state machine"),
but has not been used.  This commit therefore removes it.

If it turns out to be needed later, this commit can always be reverted.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-08 18:52:39 -07:00
Paul E. McKenney
f7a10a9750 rcu: Remove the RCU_KTHREAD_PRIO Kconfig option
Anything that can be done with the RCU_KTHREAD_PRIO Kconfig option can
also be done with the rcutree.kthread_prio kernel boot parameter.
This commit therefore removes this Kconfig option.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
2017-06-08 18:52:39 -07:00
Paul E. McKenney
90040c9e30 rcu: Remove *_SLOW_* Kconfig options
The RCU_TORTURE_TEST_SLOW_PREINIT, RCU_TORTURE_TEST_SLOW_PREINIT_DELAY,
RCU_TORTURE_TEST_SLOW_PREINIT_DELAY, RCU_TORTURE_TEST_SLOW_INIT,
RCU_TORTURE_TEST_SLOW_INIT_DELAY, RCU_TORTURE_TEST_SLOW_CLEANUP,
and RCU_TORTURE_TEST_SLOW_CLEANUP_DELAY Kconfig options are only
useful for torture testing, and there are the rcutree.gp_cleanup_delay,
rcutree.gp_init_delay, and rcutree.gp_preinit_delay kernel boot parameters
that rcutorture can use instead.  The effect of these parameters is to
artificially slow down grace period initialization and cleanup in order
to make some types of race conditions happen more often.

This commit therefore simplifies Tree RCU a bit by removing the Kconfig
options and adding the corresponding kernel parameters to rcutorture's
.boot files instead.  However, this commit also leaves out the kernel
parameters for TREE02, TREE04, and TREE07 in order to have about the
same number of tests slowed as not slowed.  TREE01, TREE03, TREE05,
and TREE06 are slowed, and the rest are not slowed.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:38 -07:00
Paul E. McKenney
a3883df393 srcu: Use rnp->lock wrappers to replace explicit memory barriers
This commit uses TREE RCU's rnp->lock wrappers to replace a few explicit
memory barriers.  This change also has the advantage of making SRCU's
memory-ordering properties be implemented in roughly the same way as they
are in Tree RCU.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:38 -07:00
Paul E. McKenney
83d40bd3bc rcu: Move rnp->lock wrappers for SRCU use
This commit moves the now-generic rnp->lock wrapper macros from
kernel/rcu/tree.h to kernel/rcu/rcu.h, thus allowing SRCU to use them.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:38 -07:00
Paul E. McKenney
bf32c76540 rcu: Convert rnp->lock wrappers to macros for SRCU use
Use of smp_mb__after_unlock_lock() would allow SRCU to omit a full
memory barrier during callback execution, so this commit converts
raw_spin_lock_rcu_node() from inline functions to type-generic macros
to allow them to handle locks in srcu_node structures as well as
rcu_node structures.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:37 -07:00
Paul E. McKenney
5f192ab027 rcu: Refactor #includes from include/linux/rcupdate.h
The list of #includes from include/linux/rcupdate.h has grown quite
a bit, so it is time to trim it.  This commit moves the #include
of include/linux/ktime.h to include/linux/rcutiny.h, along with the
Tiny-RCU-only function that was the only thing needing ktimem.h.  It then
reconstructs the files included into include/linux/ktime.h based on what
is actually needed, with significant help from the 0day Test Robot.

This single change reduces the .i file footprint from rcupdate.h from
9018 lines to 7101 lines.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:37 -07:00
Arnd Bergmann
0cb5133ab5 bcm47xx: Fix build regression
Commit 0bc2d534708b ("rcu: Refactor #includes from include/linux/rcupdate.h")
caused a build regression in an MTD partition driver:

In file included from drivers/mtd/bcm47xxpart.c:12:0:
include/linux/bcm47xx_nvram.h: In function 'bcm47xx_nvram_init_from_mem':
include/linux/bcm47xx_nvram.h:27:10: error: 'ENOTSUPP' undeclared (first use in this function)

The rcupdate.h file has no particular need for linux/errno.h, so this
commit includes linux/errno.h into bcm47xx_nvram.h.

Fixes: 0bc2d534708b ("rcu: Refactor #includes from include/linux/rcupdate.h")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:36 -07:00
Paul E. McKenney
681fbec881 lockdep: Use consistent printing primitives
Commit a5dd63efda ("lockdep: Use "WARNING" tag on lockdep splats")
substituted pr_warn() for printk() in places called out by Dmitry Vyukov.
However, this resulted in an ugly mix of pr_warn() and printk().  This
commit therefore changes printk() to pr_warn() or pr_cont(), depending
on the absence or presence of KERN_CONT.  This is done in all functions
that had printk() changed to pr_warn() by the aforementioned commit.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:36 -07:00
Paul E. McKenney
2464dd940e srcu: Apply trivial callback lists to shrink Tiny SRCU
The rcu_segcblist structure provides quite a bit of functionality, and
Tiny SRCU needs almost none of it.  So this commit replaces Tiny SRCU's
uses of rcu_segcblist with a simple singly linked list with tail pointer.
This change significantly reduces Tiny SRCU's memory footprint, more
than making up for the growth caused by the creation of rcu_segcblist.c

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:35 -07:00
Paul E. McKenney
5a0465e17a srcu: Shrink srcu.h by moving docbook and private function
The call_srcu() docbook entry is currently in include/linux/srcu.h,
which causes needless processing for each include point.  This commit
therefore moves this entry to kernel/rcu/srcutree.c, which the compiler
reads only once.  In addition, the srcu_batches_completed() function is
used only within RCU and its torture-test suites.  This commit therefore
also moves this function's declaration from include/linux/srcutiny.h,
include/linux/srcutree.h, and include/linux/srcuclassic.h to
kernel/rcu/rcu.h.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:35 -07:00
Paul E. McKenney
c350c00829 srcu: Prevent sdp->srcu_gp_seq_needed counter wrap
If a given CPU never happens to ever start an SRCU grace period, the
grace-period sequence counter might wrap.  If this CPU were to decide to
finally start a grace period, the state of its sdp->srcu_gp_seq_needed
might make it appear that it has already requested this grace period,
which would prevent starting the grace period.  If no other CPU ever started
a grace period again, this would look like a grace-period hang.  Even
if some other CPU took pity and started the needed grace period, the
leaf rcu_node structure's ->srcu_data_have_cbs field won't have record
of the fact that this CPU has a callback pending, which would look like
a very localized grace-period hang.

This might seem very unlikely, but SRCU grace periods can take less than
a microsecond on small systems, which means that overflow can happen
in much less than an hour on a 32-bit embedded system.  And embedded
systems are especially likely to have long-term idle CPUs.  Therefore,
it makes sense to prevent this scenario from happening.

This commit therefore scans each srcu_data structure occasionally,
with frequency controlled by the srcutree.counter_wrap_check kernel
boot parameter.  This parameter can be set to something like 255
in order to exercise the counter-wrap-prevention code.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:34 -07:00
Paul E. McKenney
71c40fd0b5 rcu: Move rcutiny.h to new empty/true/false-function style
This commit saves a few lines in include/linux/rcutiny.h by moving
to single-line definitions for empty functions, instead of the old
style where the two curly braces each get their own line.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:34 -07:00
Paul E. McKenney
fe21a27e8c rcu: Move rcu_request_urgent_qs_task() out of rcutiny.h and rcutree.h
The rcu_request_urgent_qs_task() function is used only within RCU,
so there is no point in exporting it to the rest of the kernel from
nclude/linux/rcutiny.h and include/linux/rcutree.h.  This commit therefore
moves this function to kernel/rcu/rcu.h.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:33 -07:00
Paul E. McKenney
e3c8d51e1a rcu: Move torture-related functions out of rcutiny.h and rcutree.h
The various functions similar to rcu_batches_started(), the
function show_rcu_gp_kthreads(), the various functions similar to
rcu_force_quiescent_state(), and the variables rcutorture_testseq and
rcutorture_vernum are used only within RCU.  There is therefore no point
in exporting them to the kernel at large from include/linux/rcutiny.h
and include/linux/rcutree.h.  This commit therefore moves all of these
to kernel/rcu/rcu.h.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:33 -07:00
Paul E. McKenney
17a8c18731 rcu: move rcupdate.h to the new true/false-function style
This commit saves a few lines in include/linux/rcupdate.h by moving
to single-line definitions for functions that just return either true
or false, instead of the old style where the two curly braces each get
their own line.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:32 -07:00
Paul E. McKenney
b8989b7605 rcu: Move rcu_ftrace_dump() from rcupdate.h to rcu.h
The rcu_ftrace_dump() function is used only internally to RCU.  This
commit therefore moves its declaration from include/linux/rcupdate.h
to kernel/rcu/rcu.h.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:32 -07:00
Paul E. McKenney
3d54f7983f rcu: Move rcu_is_nocb_cpu() from rcupdate.h to rcu.h
The rcu_is_nocb_cpu() function is used only internally to RCU.  This
commit therefore moves its declaration from include/linux/rcupdate.h
to kernel/rcu/rcu.h.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:31 -07:00
Paul E. McKenney
fa3c664769 rcu: Improve __call_rcu() debug-objects error message
The "__call_rcu(): Leaked duplicate callback" error message from
__call_rcu() has proven to be unhelpful.  This commit therefore changes
it to "__call_rcu(): Double-freed CB" and adds the value of the pointer
passed in.  The value of the pointer improves debuggability by allowing
correlation with tracing output, for example, the rcu:rcu_callback trace
event.

Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:31 -07:00
Paul E. McKenney
752de307b0 rcu: Remove linux/debugobjects.h from rcupdate.h
The include/linux/rcupdate.h file does not actually need anything from
linux/debugobjects.h, so this commit removes the inclusion.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:31 -07:00
Paul E. McKenney
82118249d0 rcu: Move the RCU_SCHEDULER_ definitions from rcupdate.h
The RCU_SCHEDULER_INACTIVE, RCU_SCHEDULER_INIT, and RCU_SCHEDULER_RUNNING
definitions are used only within RCU, so this commit moves them from
include/linux/rcupdate.h to kernel/rcu/rcu.h.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:30 -07:00
Paul E. McKenney
791875d16e rcu: Eliminate the unused __rcu_is_watching() function
The __rcu_is_watching() function is currently not used, aside from
to implement the rcu_is_watching() function.  This commit therefore
eliminates __rcu_is_watching(), which has the beneficial side-effect
of shrinking include/linux/rcupdate.h a bit.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:30 -07:00