BPF alignment tests got a conflict because the registers
are output as Rn_w instead of just Rn in net-next, and
in net a fixup for a testcase prohibits logical operations
on pointers before using them.
Also, we should attempt to patch BPF call args if JIT always on is
enabled. Instead, if we fail to JIT the subprogs we should pass
an error back up and fail immediately.
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Borkmann says:
====================
pull-request: bpf 2018-01-09
The following pull-request contains BPF updates for your *net* tree.
The main changes are:
1) Prevent out-of-bounds speculation in BPF maps by masking the
index after bounds checks in order to fix spectre v1, and
add an option BPF_JIT_ALWAYS_ON into Kconfig that allows for
removing the BPF interpreter from the kernel in favor of
JIT-only mode to make spectre v2 harder, from Alexei.
2) Remove false sharing of map refcount with max_entries which
was used in spectre v1, from Daniel.
3) Add a missing NULL psock check in sockmap in order to fix
a race, from John.
4) Fix test_align BPF selftest case since a recent change in
verifier rejects the bit-wise arithmetic on pointers
earlier but test_align update was missing, from Alexei.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The BPF interpreter has been used as part of the spectre 2 attack CVE-2017-5715.
A quote from goolge project zero blog:
"At this point, it would normally be necessary to locate gadgets in
the host kernel code that can be used to actually leak data by reading
from an attacker-controlled location, shifting and masking the result
appropriately and then using the result of that as offset to an
attacker-controlled address for a load. But piecing gadgets together
and figuring out which ones work in a speculation context seems annoying.
So instead, we decided to use the eBPF interpreter, which is built into
the host kernel - while there is no legitimate way to invoke it from inside
a VM, the presence of the code in the host kernel's text section is sufficient
to make it usable for the attack, just like with ordinary ROP gadgets."
To make attacker job harder introduce BPF_JIT_ALWAYS_ON config
option that removes interpreter from the kernel in favor of JIT-only mode.
So far eBPF JIT is supported by:
x64, arm64, arm32, sparc64, s390, powerpc64, mips64
The start of JITed program is randomized and code page is marked as read-only.
In addition "constant blinding" can be turned on with net.core.bpf_jit_harden
v2->v3:
- move __bpf_prog_ret0 under ifdef (Daniel)
v1->v2:
- fix init order, test_bpf and cBPF (Daniel's feedback)
- fix offloaded bpf (Jakub's feedback)
- add 'return 0' dummy in case something can invoke prog->bpf_func
- retarget bpf tree. For bpf-next the patch would need one extra hunk.
It will be sent when the trees are merged back to net-next
Considered doing:
int bpf_jit_enable __read_mostly = BPF_EBPF_JIT_DEFAULT;
but it seems better to land the patch as-is and in bpf-next remove
bpf_jit_enable global variable from all JITs, consolidate in one place
and remove this jit_init() function.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Pull crypto fixes from Herbert Xu:
"This fixes the following issues:
- racy use of ctx->rcvused in af_alg
- algif_aead crash in chacha20poly1305
- freeing bogus pointer in pcrypt
- build error on MIPS in mpi
- memory leak in inside-secure
- memory overwrite in inside-secure
- NULL pointer dereference in inside-secure
- state corruption in inside-secure
- build error without CRYPTO_GF128MUL in chelsio
- use after free in n2"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: inside-secure - do not use areq->result for partial results
crypto: inside-secure - fix request allocations in invalidation path
crypto: inside-secure - free requests even if their handling failed
crypto: inside-secure - per request invalidation
lib/mpi: Fix umul_ppmm() for MIPS64r6
crypto: pcrypt - fix freeing pcrypt instances
crypto: n2 - cure use after free
crypto: af_alg - Fix race around ctx->rcvused by making it atomic_t
crypto: chacha20poly1305 - validate the digest size
crypto: chelsio - select CRYPTO_GF128MUL
Pull timer fixes from Thomas Gleixner:
"A pile of fixes for long standing issues with the timer wheel and the
NOHZ code:
- Prevent timer base confusion accross the nohz switch, which can
cause unlocked access and data corruption
- Reinitialize the stale base clock on cpu hotplug to prevent subtle
side effects including rollovers on 32bit
- Prevent an interrupt storm when the timer softirq is already
pending caused by tick_nohz_stop_sched_tick()
- Move the timer start tracepoint to a place where it actually makes
sense
- Add documentation to timerqueue functions as they caused confusion
several times now"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timerqueue: Document return values of timerqueue_add/del()
timers: Invoke timer_start_debug() where it makes sense
nohz: Prevent a timer interrupt storm in tick_nohz_stop_sched_tick()
timers: Reinitialize per cpu bases on hotplug
timers: Use deferrable base independent of base::nohz_active
Here are 2 driver core fixes for 4.15-rc6, resolving some reported
issues.
The first is a cacheinfo fix for DT based systems to resolve a reported
issue that has been around for a while, and the other is to resolve a
regression in the kobject uevent code that showed up in 4.15-rc1.
Both have been in linux-next for a while with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCWkjLCA8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+yk6GACbBZ/EqSrd5w6//4okaHJLPAi8ligAoNfcBqrH
TPQycbostUcOBHUvvoUB
=MaZG
-----END PGP SIGNATURE-----
Merge tag 'driver-core-4.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core fixes from Greg KH:
"Here are two driver core fixes for 4.15-rc6, resolving some reported
issues.
The first is a cacheinfo fix for DT based systems to resolve a
reported issue that has been around for a while, and the other is to
resolve a regression in the kobject uevent code that showed up in
4.15-rc1.
Both have been in linux-next for a while with no reported issues"
* tag 'driver-core-4.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
kobject: fix suppressing modalias in uevents delivered over netlink
drivers: base: cacheinfo: fix cache type for non-architected system cache
The return values of timerqueue_add/del() are not documented in the kernel doc
comment. Add proper documentation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: rt@linutronix.de
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Link: https://lkml.kernel.org/r/20171222145337.872681338@linutronix.de
Lots of overlapping changes. Also on the net-next side
the XDP state management is handled more in the generic
layers so undo the 'net' nfp fix which isn't applicable
in net-next.
Include a necessary change by Jakub Kicinski, with log message:
====================
cls_bpf no longer takes care of offload tracking. Make sure
netdevsim performs necessary checks. This fixes a warning
caused by TC trying to remove a filter it has not added.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Current MIPS64r6 toolchains aren't able to generate efficient
DMULU/DMUHU based code for the C implementation of umul_ppmm(), which
performs an unsigned 64 x 64 bit multiply and returns the upper and
lower 64-bit halves of the 128-bit result. Instead it widens the 64-bit
inputs to 128-bits and emits a __multi3 intrinsic call to perform a 128
x 128 multiply. This is both inefficient, and it results in a link error
since we don't include __multi3 in MIPS linux.
For example commit 90a53e4432 ("cfg80211: implement regdb signature
checking") merged in v4.15-rc1 recently broke the 64r6_defconfig and
64r6el_defconfig builds by indirectly selecting MPILIB. The same build
errors can be reproduced on older kernels by enabling e.g. CRYPTO_RSA:
lib/mpi/generic_mpih-mul1.o: In function `mpihelp_mul_1':
lib/mpi/generic_mpih-mul1.c:50: undefined reference to `__multi3'
lib/mpi/generic_mpih-mul2.o: In function `mpihelp_addmul_1':
lib/mpi/generic_mpih-mul2.c:49: undefined reference to `__multi3'
lib/mpi/generic_mpih-mul3.o: In function `mpihelp_submul_1':
lib/mpi/generic_mpih-mul3.c:49: undefined reference to `__multi3'
lib/mpi/mpih-div.o In function `mpihelp_divrem':
lib/mpi/mpih-div.c:205: undefined reference to `__multi3'
lib/mpi/mpih-div.c:142: undefined reference to `__multi3'
Therefore add an efficient MIPS64r6 implementation of umul_ppmm() using
inline assembly and the DMULU/DMUHU instructions, to prevent __multi3
calls being emitted.
Fixes: 7fd08ca58a ("MIPS: Add build support for the MIPS R6 ISA")
Signed-off-by: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-mips@linux-mips.org
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The commit 4a336a23d6 ("kobject: copy env blob in one go") optimized
constructing uevent data for delivery over netlink by using the raw
environment buffer, instead of reconstructing it from individual
environment pointers. Unfortunately in doing so it broke suppressing
MODALIAS attribute for KOBJ_UNBIND events, as the code that suppressed this
attribute only adjusted the environment pointers, but left the buffer
itself alone. Let's fix it by making sure the offending attribute is
obliterated form the buffer as well.
Reported-by: Tariq Toukan <tariqt@mellanox.com>
Reported-by: Casey Leedom <leedom@chelsio.com>
Fixes: 4a336a23d6 ("kobject: copy env blob in one go")
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Daniel Borkmann says:
====================
pull-request: bpf 2017-12-17
The following pull-request contains BPF updates for your *net* tree.
The main changes are:
1) Fix a corner case in generic XDP where we have non-linear skbs
but enough tailroom in the skb to not miss to linearizing there,
from Song.
2) Fix BPF JIT bugs in s390x and ppc64 to not recache skb data when
BPF context is not skb, from Daniel.
3) Fix a BPF JIT bug in sparc64 where recaching skb data after helper
call would use the wrong register for the skb, from Daniel.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Three sets of overlapping changes, two in the packet scheduler
and one in the meson-gxl PHY driver.
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull locking fixes from Ingo Molnar:
"Misc fixes:
- Fix a S390 boot hang that was caused by the lock-break logic.
Remove lock-break to begin with, as review suggested it was
unreasonably fragile and our confidence in its continued good
health is lower than our confidence in its removal.
- Remove the lockdep cross-release checking code for now, because of
unresolved false positive warnings. This should make lockdep work
well everywhere again.
- Get rid of the final (and single) ACCESS_ONCE() straggler and
remove the API from v4.15.
- Fix a liblockdep build warning"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tools/lib/lockdep: Add missing declaration of 'pr_cont()'
checkpatch: Remove ACCESS_ONCE() warning
compiler.h: Remove ACCESS_ONCE()
tools/include: Remove ACCESS_ONCE()
tools/perf: Convert ACCESS_ONCE() to READ_ONCE()
locking/lockdep: Remove the cross-release locking checks
locking/core: Remove break_lock field when CONFIG_GENERIC_LOCKBREAK=y
locking/core: Fix deadlock during boot on systems with GENERIC_LOCKBREAK
Add a test that i) uses LD_ABS, ii) zeroing R6 before call, iii) calls
a helper that triggers reload of cached skb data, iv) uses LD_ABS again.
It's added for test_bpf in order to do runtime testing after JITing as
well as test_verifier to test that the sequence is allowed.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add a variant of rbtree_replace_node() that maintains the leftmost cache
of struct rbtree_root_cached when replacing nodes within the rbtree.
As drm_mm is the only rb_replace_node() being used on an interval tree,
the mistake looks fairly self-contained. Furthermore the only user of
drm_mm_replace_node() is its testsuite...
Testcase: igt/drm_mm/replace
Link: http://lkml.kernel.org/r/20171122100729.3742-1-chris@chris-wilson.co.uk
Link: https://patchwork.freedesktop.org/patch/msgid/20171109212435.9265-1-chris@chris-wilson.co.uk
Fixes: f808c13fd3 ("lib/interval_tree: fast overlap detection")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This code (CONFIG_LOCKDEP_CROSSRELEASE=y and CONFIG_LOCKDEP_COMPLETIONS=y),
while it found a number of old bugs initially, was also causing too many
false positives that caused people to disable lockdep - which is arguably
a worse overall outcome.
If we disable cross-release by default but keep the code upstream then
in practice the most likely outcome is that we'll allow the situation
to degrade gradually, by allowing entropy to introduce more and more
false positives, until it overwhelms maintenance capacity.
Another bad side effect was that people were trying to work around
the false positives by uglifying/complicating unrelated code. There's
a marked difference between annotating locking operations and
uglifying good code just due to bad lock debugging code ...
This gradual decrease in quality happened to a number of debugging
facilities in the kernel, and lockdep is pretty complex already,
so we cannot risk this outcome.
Either cross-release checking can be done right with no false positives,
or it should not be included in the upstream kernel.
( Note that it might make sense to maintain it out of tree and go through
the false positives every now and then and see whether new bugs were
introduced. )
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
To allocate the array of bucket locks for the hash table we now
call library function alloc_bucket_spinlocks. This function is
based on the old alloc_bucket_locks in rhashtable and should
produce the same effect.
Signed-off-by: Tom Herbert <tom@quantonium.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add two new library functions: alloc_bucket_spinlocks and
free_bucket_spinlocks. These are used to allocate and free an array
of spinlocks that are useful as locks for hash buckets. The interface
specifies the maximum number of spinlocks in the array as well
as a CPU multiplier to derive the number of spinlocks to allocate.
The number allocated is rounded up to a power of two to make the
array amenable to hash lookup.
Signed-off-by: Tom Herbert <tom@quantonium.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This function is like rhashtable_walk_next except that it only returns
the current element in the inter and does not advance the iter.
This patch also creates __rhashtable_walk_find_next. It finds the next
element in the table when the entry cached in iter is NULL or at the end
of a slot. __rhashtable_walk_find_next is called from
rhashtable_walk_next and rhastable_walk_peek.
end_of_table is an added field to the iter structure. This indicates
that the end of table was reached (walker.tbl being NULL is not a
sufficient condition for end of table).
Signed-off-by: Tom Herbert <tom@quantonium.net>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Most callers of rhashtable_walk_start don't care about a resize event
which is indicated by a return value of -EAGAIN. So calls to
rhashtable_walk_start are wrapped wih code to ignore -EAGAIN. Something
like this is common:
ret = rhashtable_walk_start(rhiter);
if (ret && ret != -EAGAIN)
goto out;
Since zero and -EAGAIN are the only possible return values from the
function this check is pointless. The condition never evaluates to true.
This patch changes rhashtable_walk_start to return void. This simplifies
code for the callers that ignore -EAGAIN. For the few cases where the
caller cares about the resize event, particularly where the table can be
walked in mulitple parts for netlink or seq file dump, the function
rhashtable_walk_start_check has been added that returns -EAGAIN on a
resize event.
Signed-off-by: Tom Herbert <tom@quantonium.net>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Callers of sprint_oid() do not check its return value before printing
the result. In the case where the OID is zero-length, -EBADMSG was
being returned without anything being written to the buffer, resulting
in uninitialized stack memory being printed. Fix this by writing
"(bad)" to the buffer in the cases where -EBADMSG is returned.
Fixes: 4f73175d03 ("X.509: Add utility functions to render OIDs as strings")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
In sprint_oid(), if the input buffer were to be more than 1 byte too
small for the first snprintf(), 'bufsize' would underflow, causing a
buffer overflow when printing the remainder of the OID.
Fortunately this cannot actually happen currently, because no users pass
in a buffer that can be too small for the first snprintf().
Regardless, fix it by checking the snprintf() return value correctly.
For consistency also tweak the second snprintf() check to look the same.
Fixes: 4f73175d03 ("X.509: Add utility functions to render OIDs as strings")
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
asn1_ber_decoder() was ignoring errors from actions associated with the
opcodes ASN1_OP_END_SEQ_ACT, ASN1_OP_END_SET_ACT,
ASN1_OP_END_SEQ_OF_ACT, and ASN1_OP_END_SET_OF_ACT. In practice, this
meant the pkcs7_note_signed_info() action (since that was the only user
of those opcodes). Fix it by checking for the error, just like the
decoder does for actions associated with the other opcodes.
This bug allowed users to leak slab memory by repeatedly trying to add a
specially crafted "pkcs7_test" key (requires CONFIG_PKCS7_TEST_KEY).
In theory, this bug could also be used to bypass module signature
verification, by providing a PKCS#7 message that is misparsed such that
a signature's ->authattrs do not contain its ->msgdigest. But it
doesn't seem practical in normal cases, due to restrictions on the
format of the ->authattrs.
Fixes: 42d5ec27f8 ("X.509: Add an ASN.1 decoder")
Cc: <stable@vger.kernel.org> # v3.7+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
In asn1_ber_decoder(), indefinitely-sized ASN.1 items were being passed
to the action functions before their lengths had been computed, using
the bogus length of 0x80 (ASN1_INDEFINITE_LENGTH). This resulted in
reading data past the end of the input buffer, when given a specially
crafted message.
Fix it by rearranging the code so that the indefinite length is resolved
before the action is called.
This bug was originally found by fuzzing the X.509 parser in userspace
using libFuzzer from the LLVM project.
KASAN report (cleaned up slightly):
BUG: KASAN: slab-out-of-bounds in memcpy ./include/linux/string.h:341 [inline]
BUG: KASAN: slab-out-of-bounds in x509_fabricate_name.constprop.1+0x1a4/0x940 crypto/asymmetric_keys/x509_cert_parser.c:366
Read of size 128 at addr ffff880035dd9eaf by task keyctl/195
CPU: 1 PID: 195 Comm: keyctl Not tainted 4.14.0-09238-g1d3b78bbc6e9 #26
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-20171110_100015-anatol 04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0xd1/0x175 lib/dump_stack.c:53
print_address_description+0x78/0x260 mm/kasan/report.c:252
kasan_report_error mm/kasan/report.c:351 [inline]
kasan_report+0x23f/0x350 mm/kasan/report.c:409
memcpy+0x1f/0x50 mm/kasan/kasan.c:302
memcpy ./include/linux/string.h:341 [inline]
x509_fabricate_name.constprop.1+0x1a4/0x940 crypto/asymmetric_keys/x509_cert_parser.c:366
asn1_ber_decoder+0xb4a/0x1fd0 lib/asn1_decoder.c:447
x509_cert_parse+0x1c7/0x620 crypto/asymmetric_keys/x509_cert_parser.c:89
x509_key_preparse+0x61/0x750 crypto/asymmetric_keys/x509_public_key.c:174
asymmetric_key_preparse+0xa4/0x150 crypto/asymmetric_keys/asymmetric_type.c:388
key_create_or_update+0x4d4/0x10a0 security/keys/key.c:850
SYSC_add_key security/keys/keyctl.c:122 [inline]
SyS_add_key+0xe8/0x290 security/keys/keyctl.c:62
entry_SYSCALL_64_fastpath+0x1f/0x96
Allocated by task 195:
__do_kmalloc_node mm/slab.c:3675 [inline]
__kmalloc_node+0x47/0x60 mm/slab.c:3682
kvmalloc ./include/linux/mm.h:540 [inline]
SYSC_add_key security/keys/keyctl.c:104 [inline]
SyS_add_key+0x19e/0x290 security/keys/keyctl.c:62
entry_SYSCALL_64_fastpath+0x1f/0x96
Fixes: 42d5ec27f8 ("X.509: Add an ASN.1 decoder")
Reported-by: Alexander Potapenko <glider@google.com>
Cc: <stable@vger.kernel.org> # v3.7+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Commit 28033ae4e0 ("net: netlink: Update attr validation to require
exact length for some types") requires attributes using types NLA_U* and
NLA_S* to have an exact length. This change is exposing bugs in various
userspace commands that are sending attributes with an invalid length
(e.g., attribute has type NLA_U8 and userspace sends NLA_U32). While
the commands are clearly broken and need to be fixed, users are arguing
that the sudden change in enforcement is breaking older commands on
newer kernels for use cases that otherwise "worked".
Relax the validation to print a warning mesage similar to what is done
for messages containing extra bytes after parsing.
Fixes: 28033ae4e0 ("net: netlink: Update attr validation to require exact length for some types")
Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This tag contains a handful of small cleanups that are a result of
feedback that didn't make it into our original patch set, either because
the feedback hadn't been given yet, I missed the original emails, or
we weren't ready to submit the changes yet.
I've been maintaining the various cleanup patch sets I have as their own
branches, which I then merged together and signed. Each merge commit
has a short summary of the changes, and each branch is based on your
latest tag (4.15-rc1, in this case). If this isn't the right way to do
this then feel free to suggest something else, but it seems sane to me.
Here's a short summary of the changes, roughly in order of how
interesting they are.
* libgcc.h has been moved from include/lib, where it's the only member,
to include/linux. This is meant to avoid tab completion conflicts.
* VDSO entries for clock_get/gettimeofday/getcpu have been added. These
are simple syscalls now, but we want to let glibc use them from the
start so we can make them faster later.
* A VDSO entry for instruction cache flushing has been added so
userspace can flush the instruction cache.
* The VDSO symbol versions for __vdso_cmpxchg{32,64} have been removed,
as those VDSO entries don't actually exist.
* __io_writes has been corrected to respect the given type.
* A new READ_ONCE in arch_spin_is_locked().
* __test_and_op_bit_ord() is now actually ordered.
* Various small fixes throughout the tree to enable allmodconfig to
build cleanly.
* Removal of some dead code in our atomic support headers.
* Improvements to various comments in our atomic support headers.
-----BEGIN PGP SIGNATURE-----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=CCe+
-----END PGP SIGNATURE-----
Merge tag 'riscv-for-linus-4.15-rc2_cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux
Pull RISC-V cleanups and ABI fixes from Palmer Dabbelt:
"This contains a handful of small cleanups that are a result of
feedback that didn't make it into our original patch set, either
because the feedback hadn't been given yet, I missed the original
emails, or we weren't ready to submit the changes yet.
I've been maintaining the various cleanup patch sets I have as their
own branches, which I then merged together and signed. Each merge
commit has a short summary of the changes, and each branch is based on
your latest tag (4.15-rc1, in this case). If this isn't the right way
to do this then feel free to suggest something else, but it seems sane
to me.
Here's a short summary of the changes, roughly in order of how
interesting they are.
- libgcc.h has been moved from include/lib, where it's the only
member, to include/linux. This is meant to avoid tab completion
conflicts.
- VDSO entries for clock_get/gettimeofday/getcpu have been added.
These are simple syscalls now, but we want to let glibc use them
from the start so we can make them faster later.
- A VDSO entry for instruction cache flushing has been added so
userspace can flush the instruction cache.
- The VDSO symbol versions for __vdso_cmpxchg{32,64} have been
removed, as those VDSO entries don't actually exist.
- __io_writes has been corrected to respect the given type.
- A new READ_ONCE in arch_spin_is_locked().
- __test_and_op_bit_ord() is now actually ordered.
- Various small fixes throughout the tree to enable allmodconfig to
build cleanly.
- Removal of some dead code in our atomic support headers.
- Improvements to various comments in our atomic support headers"
* tag 'riscv-for-linus-4.15-rc2_cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux: (23 commits)
RISC-V: __io_writes should respect the length argument
move libgcc.h to include/linux
RISC-V: Clean up an unused include
RISC-V: Allow userspace to flush the instruction cache
RISC-V: Flush I$ when making a dirty page executable
RISC-V: Add missing include
RISC-V: Use define for get_cycles like other architectures
RISC-V: Provide stub of setup_profiling_timer()
RISC-V: Export some expected symbols for modules
RISC-V: move empty_zero_page definition to C and export it
RISC-V: io.h: type fixes for warnings
RISC-V: use RISCV_{INT,SHORT} instead of {INT,SHORT} for asm macros
RISC-V: use generic serial.h
RISC-V: remove spin_unlock_wait()
RISC-V: `sfence.vma` orderes the instruction cache
RISC-V: Add READ_ONCE in arch_spin_is_locked()
RISC-V: __test_and_op_bit_ord should be strongly ordered
RISC-V: Remove smb_mb__{before,after}_spinlock()
RISC-V: Remove __smp_bp__{before,after}_atomic
RISC-V: Comment on why {,cmp}xchg is ordered how it is
...
Introducing a new include/lib directory just for this file totally
messes up tab completion for include/linux, which is highly annoying.
Move it to include/linux where we have headers for all kinds of other
lib/ code as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Instead, just fall back on the new '%p' behavior which hashes the
pointer.
Otherwise, '%pK' - that was intended to mark a pointer as restricted -
just ends up leaking pointers that a normal '%p' wouldn't leak. Which
just make the whole thing pointless.
I suspect we should actually get rid of '%pK' entirely, and make it just
work as '%p' regardless, but this is the minimal obvious fix. People
who actually use 'kptr_restrict' should weigh in on which behavior they
want.
Cc: Tobin Harding <me@tobin.cc>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
printk specifier %p now hashes all addresses before printing. Sometimes
we need to see the actual unmodified address. This can be achieved using
%lx but then we face the risk that if in future we want to change the
way the Kernel handles printing of pointers we will have to grep through
the already existent 50 000 %lx call sites. Let's add specifier %px as a
clear, opt-in, way to print a pointer and maintain some level of
isolation from all the other hex integer output within the Kernel.
Add printk specifier %px to print the actual unmodified address.
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Currently there exist approximately 14 000 places in the kernel where
addresses are being printed using an unadorned %p. This potentially
leaks sensitive information regarding the Kernel layout in memory. Many
of these calls are stale, instead of fixing every call lets hash the
address by default before printing. This will of course break some
users, forcing code printing needed addresses to be updated.
Code that _really_ needs the address will soon be able to use the new
printk specifier %px to print the address.
For what it's worth, usage of unadorned %p can be broken down as
follows (thanks to Joe Perches).
$ git grep -E '%p[^A-Za-z0-9]' | cut -f1 -d"/" | sort | uniq -c
1084 arch
20 block
10 crypto
32 Documentation
8121 drivers
1221 fs
143 include
101 kernel
69 lib
100 mm
1510 net
40 samples
7 scripts
11 security
166 sound
152 tools
2 virt
Add function ptr_to_id() to map an address to a 32 bit unique
identifier. Hash any unadorned usage of specifier %p and any malformed
specifiers.
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Currently code to handle %pK is all within the switch statement in
pointer(). This is the wrong level of abstraction. Each of the other switch
clauses call a helper function, pK should do the same.
Refactor code out of pointer() to new function restricted_pointer().
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Pull timer updates from Thomas Gleixner:
- The final conversion of timer wheel timers to timer_setup().
A few manual conversions and a large coccinelle assisted sweep and
the removal of the old initialization mechanisms and the related
code.
- Remove the now unused VSYSCALL update code
- Fix permissions of /proc/timer_list. I still need to get rid of that
file completely
- Rename a misnomed clocksource function and remove a stale declaration
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
m68k/macboing: Fix missed timer callback assignment
treewide: Remove TIMER_FUNC_TYPE and TIMER_DATA_TYPE casts
timer: Remove redundant __setup_timer*() macros
timer: Pass function down to initialization routines
timer: Remove unused data arguments from macros
timer: Switch callback prototype to take struct timer_list * argument
timer: Pass timer_list pointer to callbacks unconditionally
Coccinelle: Remove setup_timer.cocci
timer: Remove setup_*timer() interface
timer: Remove init_timer() interface
treewide: setup_timer() -> timer_setup() (2 field)
treewide: setup_timer() -> timer_setup()
treewide: init_timer() -> setup_timer()
treewide: Switch DEFINE_TIMER callbacks to struct timer_list *
s390: cmm: Convert timers to use timer_setup()
lightnvm: Convert timers to use timer_setup()
drivers/net: cris: Convert timers to use timer_setup()
drm/vc4: Convert timers to use timer_setup()
block/laptop_mode: Convert timers to use timer_setup()
net/atm/mpc: Avoid open-coded assignment of timer callback function
...
General changes:
* Unconfuse get_unmapped_area and point/unpoint driver methods
* New partition parser: sharpslpart
* Kill GENERIC_IO
* Various fixes
NAND changes:
* Add a flag to mark NANDs that require 3 address cycles to encode a
page address
* Set a default ECC/free layout when NAND_ECC_NONE is requested
* Fix a bug in panic_nand_write()
* Another batch of cleanups for the denali driver
* Fix PM support in the atmel driver
* Remove support for platform data in the omap driver
* Fix subpage write in the omap driver
* Fix irq handling in the mtk driver
* Change link order of mtk_ecc and mtk_nand drivers to speed up boot
time
* Change log level of ECC error messages in the mxc driver
* Patch the pxa3xx driver to support Armada 8k platforms
* Add BAM DMA support to the qcom driver
* Convert gpio-nand to the GPIO desc API
* Fix ECC handling in the mt29f driver
SPI-NOR changes:
* Introduce system power management support
* New mechanism to select the proper .quad_enable() hook by JEDEC ID,
when needed, instead of only by manufacturer ID
* Add support to new memory parts from Gigadevice, Winbond, Macronix and
Everspin
* Maintainance for Cadence, Intel, Mediatek and STM32 drivers
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2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=wVm7
-----END PGP SIGNATURE-----
Merge tag 'for-linus-20171120' of git://git.infradead.org/linux-mtd
Pull MTD updates from Richard Weinberger:
"General changes:
- Unconfuse get_unmapped_area and point/unpoint driver methods
- New partition parser: sharpslpart
- Kill GENERIC_IO
- Various fixes
NAND changes:
- Add a flag to mark NANDs that require 3 address cycles to encode a
page address
- Set a default ECC/free layout when NAND_ECC_NONE is requested
- Fix a bug in panic_nand_write()
- Another batch of cleanups for the denali driver
- Fix PM support in the atmel driver
- Remove support for platform data in the omap driver
- Fix subpage write in the omap driver
- Fix irq handling in the mtk driver
- Change link order of mtk_ecc and mtk_nand drivers to speed up boot
time
- Change log level of ECC error messages in the mxc driver
- Patch the pxa3xx driver to support Armada 8k platforms
- Add BAM DMA support to the qcom driver
- Convert gpio-nand to the GPIO desc API
- Fix ECC handling in the mt29f driver
SPI-NOR changes:
- Introduce system power management support
- New mechanism to select the proper .quad_enable() hook by JEDEC
ID, when needed, instead of only by manufacturer ID
- Add support to new memory parts from Gigadevice, Winbond, Macronix
and Everspin
- Maintainance for Cadence, Intel, Mediatek and STM32 drivers"
* tag 'for-linus-20171120' of git://git.infradead.org/linux-mtd: (85 commits)
mtd: Avoid probe failures when mtd->dbg.dfs_dir is invalid
mtd: sharpslpart: Add sharpslpart partition parser
mtd: Add sanity checks in mtd_write/read_oob()
mtd: remove the get_unmapped_area method
mtd: implement mtd_get_unmapped_area() using the point method
mtd: chips/map_rom.c: implement point and unpoint methods
mtd: chips/map_ram.c: implement point and unpoint methods
mtd: mtdram: properly handle the phys argument in the point method
mtd: mtdswap: fix spelling mistake: 'TRESHOLD' -> 'THRESHOLD'
mtd: slram: use memremap() instead of ioremap()
kconfig: kill off GENERIC_IO option
mtd: Fix C++ comment in include/linux/mtd/mtd.h
mtd: constify mtd_partition
mtd: plat-ram: Replace manual resource management by devm
mtd: nand: Fix writing mtdoops to nand flash.
mtd: intel-spi: Add Intel Lewisburg PCH SPI super SKU PCI ID
mtd: nand: mtk: fix infinite ECC decode IRQ issue
mtd: spi-nor: Add support for mr25h128
mtd: nand: mtk: change the compile sequence of mtk_nand.o and mtk_ecc.o
mtd: spi-nor: enable 4B opcodes for mx66l51235l
...
This changes all DEFINE_TIMER() callbacks to use a struct timer_list
pointer instead of unsigned long. Since the data argument has already been
removed, none of these callbacks are using their argument currently, so
this renames the argument to "unused".
Done using the following semantic patch:
@match_define_timer@
declarer name DEFINE_TIMER;
identifier _timer, _callback;
@@
DEFINE_TIMER(_timer, _callback);
@change_callback depends on match_define_timer@
identifier match_define_timer._callback;
type _origtype;
identifier _origarg;
@@
void
-_callback(_origtype _origarg)
+_callback(struct timer_list *unused)
{ ... }
Signed-off-by: Kees Cook <keescook@chromium.org>
The flag enables Clang instrumentation of comparison operations
(currently not supported by GCC). This instrumentation is needed by the
new KCOV device to collect comparison operands.
Link: http://lkml.kernel.org/r/20171011095459.70721-2-glider@google.com
Signed-off-by: Victor Chibotaru <tchibo@google.com>
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: <syzkaller@googlegroups.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
find_bit functions are widely used in the kernel, including hot paths.
This module tests performance of those functions in 2 typical scenarios:
randomly filled bitmap with relatively equal distribution of set and
cleared bits, and sparse bitmap which has 1 set bit for 500 cleared
bits.
On ThunderX machine:
Start testing find_bit() with random-filled bitmap
find_next_bit: 240043 cycles, 164062 iterations
find_next_zero_bit: 312848 cycles, 163619 iterations
find_last_bit: 193748 cycles, 164062 iterations
find_first_bit: 177720874 cycles, 164062 iterations
Start testing find_bit() with sparse bitmap
find_next_bit: 3633 cycles, 656 iterations
find_next_zero_bit: 620399 cycles, 327025 iterations
find_last_bit: 3038 cycles, 656 iterations
find_first_bit: 691407 cycles, 656 iterations
[arnd@arndb.de: use correct format string for find-bit tests]
Link: http://lkml.kernel.org/r/20171113135605.3166307-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/20171109140714.13168-1-ynorov@caviumnetworks.com
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Clement Courbet <courbet@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fengguang reported soft lockups while running the rbtree and interval
tree test modules. The logic for these tests all occur in init phase,
and we currently are pounding with the default values for number of
nodes and number of iterations of each test. Reduce the latter by two
orders of magnitude. This does not influence the value of the tests in
that one thousand times by default is enough to get the picture.
Link: http://lkml.kernel.org/r/20171109161715.xai2dtwqw2frhkcm@linux-n805
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the amount of resources allocated to a gen_pool exceeds 2^32 then the
avail atomic overflows and this causes problems when clients try and
borrow resources from the pool. This is only expected to be an issue on
64 bit systems.
Add the <linux/atomic.h> header to pull in atomic_long* operations. So
that 32 bit systems continue to use atomic32_t but 64 bit systems can
use atomic64_t.
Link: http://lkml.kernel.org/r/1509033843-25667-1-git-send-email-sbates@raithlin.com
Signed-off-by: Stephen Bates <sbates@raithlin.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Daniel Mentz <danielmentz@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Our current int_sqrt() is not rough nor any approximation; it calculates
the exact value of: floor(sqrt()). Document this.
Link: http://lkml.kernel.org/r/20171020164645.001652117@infradead.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Anshul Garg <aksgarg1989@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Michael Davidson <md@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The initial value (@m) compute is:
m = 1UL << (BITS_PER_LONG - 2);
while (m > x)
m >>= 2;
Which is a linear search for the highest even bit smaller or equal to @x
We can implement this using a binary search using __fls() (or better when
its hardware implemented).
m = 1UL << (__fls(x) & ~1UL);
Especially for small values of @x; which are the more common arguments
when doing a CDF on idle times; the linear search is near to worst case,
while the binary search of __fls() is a constant 6 (or 5 on 32bit)
branches.
cycles: branches: branch-misses:
PRE:
hot: 43.633557 +- 0.034373 45.333132 +- 0.002277 0.023529 +- 0.000681
cold: 207.438411 +- 0.125840 45.333132 +- 0.002277 6.976486 +- 0.004219
SOFTWARE FLS:
hot: 29.576176 +- 0.028850 26.666730 +- 0.004511 0.019463 +- 0.000663
cold: 165.947136 +- 0.188406 26.666746 +- 0.004511 6.133897 +- 0.004386
HARDWARE FLS:
hot: 24.720922 +- 0.025161 20.666784 +- 0.004509 0.020836 +- 0.000677
cold: 132.777197 +- 0.127471 20.666776 +- 0.004509 5.080285 +- 0.003874
Averages computed over all values <128k using a LFSR to generate order.
Cold numbers have a LFSR based branch trace buffer 'confuser' ran between
each int_sqrt() invocation.
Link: http://lkml.kernel.org/r/20171020164644.936577234@infradead.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Suggested-by: Joe Perches <joe@perches.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Anshul Garg <aksgarg1989@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Michael Davidson <md@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current int_sqrt() computation is sub-optimal for the case of small
@x. Which is the interesting case when we're going to do cumulative
distribution functions on idle times, which we assume to be a random
variable, where the target residency of the deepest idle state gives an
upper bound on the variable (5e6ns on recent Intel chips).
In the case of small @x, the compute loop:
while (m != 0) {
b = y + m;
y >>= 1;
if (x >= b) {
x -= b;
y += m;
}
m >>= 2;
}
can be reduced to:
while (m > x)
m >>= 2;
Because y==0, b==m and until x>=m y will remain 0.
And while this is computationally equivalent, it runs much faster
because there's less code, in particular less branches.
cycles: branches: branch-misses:
OLD:
hot: 45.109444 +- 0.044117 44.333392 +- 0.002254 0.018723 +- 0.000593
cold: 187.737379 +- 0.156678 44.333407 +- 0.002254 6.272844 +- 0.004305
PRE:
hot: 67.937492 +- 0.064124 66.999535 +- 0.000488 0.066720 +- 0.001113
cold: 232.004379 +- 0.332811 66.999527 +- 0.000488 6.914634 +- 0.006568
POST:
hot: 43.633557 +- 0.034373 45.333132 +- 0.002277 0.023529 +- 0.000681
cold: 207.438411 +- 0.125840 45.333132 +- 0.002277 6.976486 +- 0.004219
Averages computed over all values <128k using a LFSR to generate order.
Cold numbers have a LFSR based branch trace buffer 'confuser' ran between
each int_sqrt() invocation.
Link: http://lkml.kernel.org/r/20171020164644.876503355@infradead.org
Fixes: 30493cc9dd ("lib/int_sqrt.c: optimize square root algorithm")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Suggested-by: Anshul Garg <aksgarg1989@gmail.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Joe Perches <joe@perches.com>
Cc: David Miller <davem@davemloft.net>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michael Davidson <md@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Omit extra messages for a memory allocation failure in these functions.
This issue was detected by using the Coccinelle software.
Link: http://lkml.kernel.org/r/410a4c5a-4ee0-6fcc-969c-103d8e496b78@users.sourceforge.net
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Extract the string test code into its own source file, to allow
compiling it either to a loadable module, or built into the kernel.
Fixes: 03270c13c5 ("lib/string.c: add testcases for memset16/32/64")
Link: http://lkml.kernel.org/r/1505397744-3387-1-git-send-email-geert@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
line-range is supposed to treat "1-" as "1-endoffile", so
handle the special case by setting last_lineno to UINT_MAX.
Fixes this error:
dynamic_debug:ddebug_parse_query: last-line:0 < 1st-line:1
dynamic_debug:ddebug_exec_query: query parse failed
Link: http://lkml.kernel.org/r/10a6a101-e2be-209f-1f41-54637824788e@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The "cut here" string is used in a few paths. Define it in a single
place.
Link: http://lkml.kernel.org/r/1510100869-73751-3-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some architectures store the WARN_ONCE state in the flags field of the
bug_entry. Clear that one too when resetting once state through
/sys/kernel/debug/clear_warn_once
Pointed out by Michael Ellerman
Improves the earlier patch that add clear_warn_once.
[ak@linux.intel.com: add a missing ifdef CONFIG_MODULES]
Link: http://lkml.kernel.org/r/20171020170633.9593-1-andi@firstfloor.org
[akpm@linux-foundation.org: fix unused var warning]
[akpm@linux-foundation.org: Use 0200 for clear_warn_once file, per mpe]
[akpm@linux-foundation.org: clear BUGFLAG_DONE in clear_once_table(), per mpe]
Link: http://lkml.kernel.org/r/20171019204642.7404-1-andi@firstfloor.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
