The build of frv allmodconfig was failing with the errors like:
/tmp/cc0JSPc3.s: Assembler messages:
/tmp/cc0JSPc3.s:1839: Error: symbol `.LSLT0' is already defined
/tmp/cc0JSPc3.s:1842: Error: symbol `.LASLTP0' is already defined
/tmp/cc0JSPc3.s:1969: Error: symbol `.LELTP0' is already defined
/tmp/cc0JSPc3.s:1970: Error: symbol `.LELT0' is already defined
Commit 866ced950b ("kbuild: Support split debug info v4") introduced
splitting the debug info and keeping that in a separate file. Somehow,
the frv-linux gcc did not like that and I am guessing that instead of
splitting it started copying. The first report about this is at:
https://lists.01.org/pipermail/kbuild-all/2015-July/010527.html.
I will try and see if this can work with frv and if still fails I will
open a bug report with gcc. But meanwhile this is the easiest option to
solve build failure of frv.
Fixes: 866ced950b ("kbuild: Support split debug info v4")
Link: http://lkml.kernel.org/r/1482062348-5352-1-git-send-email-sudipm.mukherjee@gmail.com
Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SipHash is a 64-bit keyed hash function that is actually a
cryptographically secure PRF, like HMAC. Except SipHash is super fast,
and is meant to be used as a hashtable keyed lookup function, or as a
general PRF for short input use cases, such as sequence numbers or RNG
chaining.
For the first usage:
There are a variety of attacks known as "hashtable poisoning" in which an
attacker forms some data such that the hash of that data will be the
same, and then preceeds to fill up all entries of a hashbucket. This is
a realistic and well-known denial-of-service vector. Currently
hashtables use jhash, which is fast but not secure, and some kind of
rotating key scheme (or none at all, which isn't good). SipHash is meant
as a replacement for jhash in these cases.
There are a modicum of places in the kernel that are vulnerable to
hashtable poisoning attacks, either via userspace vectors or network
vectors, and there's not a reliable mechanism inside the kernel at the
moment to fix it. The first step toward fixing these issues is actually
getting a secure primitive into the kernel for developers to use. Then
we can, bit by bit, port things over to it as deemed appropriate.
While SipHash is extremely fast for a cryptographically secure function,
it is likely a bit slower than the insecure jhash, and so replacements
will be evaluated on a case-by-case basis based on whether or not the
difference in speed is negligible and whether or not the current jhash usage
poses a real security risk.
For the second usage:
A few places in the kernel are using MD5 or SHA1 for creating secure
sequence numbers, syn cookies, port numbers, or fast random numbers.
SipHash is a faster and more fitting, and more secure replacement for MD5
in those situations. Replacing MD5 and SHA1 with SipHash for these uses is
obvious and straight-forward, and so is submitted along with this patch
series. There shouldn't be much of a debate over its efficacy.
Dozens of languages are already using this internally for their hash
tables and PRFs. Some of the BSDs already use this in their kernels.
SipHash is a widely known high-speed solution to a widely known set of
problems, and it's time we catch-up.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
hotcpu_notifier(), cpu_notifier(), __hotcpu_notifier(), __cpu_notifier(),
register_hotcpu_notifier(), register_cpu_notifier(),
__register_hotcpu_notifier(), __register_cpu_notifier(),
unregister_hotcpu_notifier(), unregister_cpu_notifier(),
__unregister_hotcpu_notifier(), __unregister_cpu_notifier()
are unused now. Remove them and all related code.
Remove also the now pointless cpu notifier error injection mechanism. The
states can be executed step by step and error rollback is the same as cpu
down, so any state transition can be tested w/o requiring the notifier
error injection.
Some CPU hotplug states are kept as they are (ab)used for hotplug state
tracking.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20161221192112.005642358@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull documentation update from Jonathan Corbet:
"These are the documentation changes for 4.10.
It's another busy cycle for the docs tree, as the sphinx conversion
continues. Highlights include:
- Further work on PDF output, which remains a bit of a pain but
should be more solid now.
- Five more DocBook template files converted to Sphinx. Only 27 to
go... Lots of plain-text files have also been converted and
integrated.
- Images in binary formats have been replaced with more
source-friendly versions.
- Various bits of organizational work, including the renaming of
various files discussed at the kernel summit.
- New documentation for the device_link mechanism.
... and, of course, lots of typo fixes and small updates"
* tag 'docs-4.10' of git://git.lwn.net/linux: (193 commits)
dma-buf: Extract dma-buf.rst
Update Documentation/00-INDEX
docs: 00-INDEX: document directories/files with no docs
docs: 00-INDEX: remove non-existing entries
docs: 00-INDEX: add missing entries for documentation files/dirs
docs: 00-INDEX: consolidate process/ and admin-guide/ description
scripts: add a script to check if Documentation/00-INDEX is sane
Docs: change sh -> awk in REPORTING-BUGS
Documentation/core-api/device_link: Add initial documentation
core-api: remove an unexpected unident
ppc/idle: Add documentation for powersave=off
Doc: Correct typo, "Introdution" => "Introduction"
Documentation/atomic_ops.txt: convert to ReST markup
Documentation/local_ops.txt: convert to ReST markup
Documentation/assoc_array.txt: convert to ReST markup
docs-rst: parse-headers.pl: cleanup the documentation
docs-rst: fix media cleandocs target
docs-rst: media/Makefile: reorganize the rules
docs-rst: media: build SVG from graphviz files
docs-rst: replace bayer.png by a SVG image
...
Add a configuration option to set the default console loglevel. This
is, as before, still possible to override at runtime through bootargs
(loglevel=<x>), sysrq and /proc/printk.
There are cases where adding additional arguments on the commandline is
impractical, and changing the default for the kernel when being built
makes more sense. Provide such a method here, for those who choose to
do so.
Also, while touching this code, clarify the difference between
MESSAGE_LOGLEVEL_DEFAULT and CONSOLE_LOGLEVEL_DEFAULT.
Link: http://lkml.kernel.org/r/1479676829-30031-1-git-send-email-olof@lixom.net
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull RCU updates from Paul E. McKenney:
- Documentation updates, yet again just simple changes.
- Miscellaneous fixes, including a change to call_rcu()'s
rcu_head alignment check.
- Security-motivated list consistency checks, which are
disabled by default behind DEBUG_LIST.
- Torture-test updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This new config parameter limits the space used for "Lock debugging:
prove locking correctness" by about 4MB. The current sparc systems have
the limitation of 32MB size for kernel size including .text, .data and
.bss sections. With PROVE_LOCKING feature, the kernel size could grow
beyond this limit and causing system boot-up issues. With this option,
kernel limits the size of the entries of lock_chains, stack_trace etc.,
so that kernel fits in required size limit. This is not visible to user
and only used for sparc.
Signed-off-by: Babu Moger <babu.moger@oracle.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The commit brings the RCU_TRACE Kconfig option's help text up to date
by noting that it enables additional event tracing as well as debugfs.
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
[ paulmck: Do some wordsmithing. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
The CONFIG_DEBUG_LIST option is normally meant for kernel developers
rather than production machines and is guarded by CONFIG_DEBUG_KERNEL.
In contrast, the newly added CONFIG_BUG_ON_DATA_CORRUPTION is meant
for security hardening and may be used on systems that intentionally
do not enable CONFIG_DEBUG_KERNEL. In this configuration, we get
a warning from Kconfig about the mismatched dependencies:
warning: (BUG_ON_DATA_CORRUPTION) selects DEBUG_LIST which has unmet direct dependencies (DEBUG_KERNEL)
This annotates the DEBUG_LIST option to be selectable by
BUG_ON_DATA_CORRUPTION when DEBUG_KERNEL is disabled.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 40cd725cfc7f ("bug: Provide toggle for BUG on data corruption")
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Commit 484f29c7430b3 ("bug: Provide toggle for BUG on data corruption")
added a Kconfig select statement on CONFIG_DEBUG_LIST, but the CONFIG_
prefix is only used in Make and C(PP) syntax. Remove the CONFIG_ prefix
to correctly select the Kconfig option DEBUG_LIST.
Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
The kernel checks for cases of data structure corruption under some
CONFIGs (e.g. CONFIG_DEBUG_LIST). When corruption is detected, some
systems may want to BUG() immediately instead of letting the system run
with known corruption. Usually these kinds of manipulation primitives can
be used by security flaws to gain arbitrary memory write control. This
provides a new config CONFIG_BUG_ON_DATA_CORRUPTION and a corresponding
macro CHECK_DATA_CORRUPTION for handling these situations. Notably, even
if not BUGing, the kernel should not continue processing the corrupted
structure.
This is inspired by similar hardening by Syed Rameez Mustafa in MSM
kernels, and in PaX and Grsecurity, which is likely in response to earlier
removal of the BUG calls in commit 924d9addb9 ("list debugging: use
WARN() instead of BUG()").
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
The previous patch renamed several files that are cross-referenced
along the Kernel documentation. Adjust the links to point to
the right places.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Pull kselftest updates from Shuah Khan:
"This update consists of:
- Fixes and improvements to existing tests
- Moving code from Documentation to selftests, samples, and tools:
* Moves dnotify_test, prctl, ptp, vDSO, ia64, watchdog, and
networking tests from Documentation to selftests.
* Moves mic/mpssd, misc-devices/mei, timers, watchdog, auxdisplay,
and blackfin examples from Documentation to samples.
* Moves accounting, laptops/dslm, and pcmcia/crc32hash tools from
Documentation to tools.
* Deletes BUILD_DOCSRC and its dependencies"
* tag 'linux-kselftest-4.9-rc1-update' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (21 commits)
selftests/futex: Check ANSI terminal color support
Doc: update 00-INDEX files to reflect the runnable code move
samples: move blackfin gptimers-example from Documentation
tools: move pcmcia crc32hash tool from Documentation
tools: move laptops dslm tool from Documentation
tools: move accounting tool from Documentation
samples: move auxdisplay example code from Documentation
samples: move watchdog example code from Documentation
samples: move timers example code from Documentation
samples: move misc-devices/mei example code from Documentation
samples: move mic/mpssd example code from Documentation
selftests: Move networking/timestamping from Documentation
selftests: move watchdog tests from Documentation/watchdog
selftests: move ia64 tests from Documentation/ia64
selftests: move vDSO tests from Documentation/vDSO
selftests: move ptp tests from Documentation/ptp
selftests: move prctl tests from Documentation/prctl
selftests: move dnotify_test from Documentation/filesystems
selftests/timers: Add missing error code assignment before test
selftests/zram: replace ZRAM_LZ4_COMPRESS
...
Move blackfin gptimers-example to samples and remove it from Documentation
Makefile. Update samples Kconfig and Makefile to build gptimers-example.
blackfin is the last CONFIG_BUILD_DOCSRC target in Documentation/Makefile.
Hence this patch also includes changes to remove CONFIG_BUILD_DOCSRC from
Makefile and lib/Kconfig.debug and updates VIDEO_PCI_SKELETON dependency
on BUILD_DOCSRC.
Documentation/Makefile is not deleted to avoid braking make htmldocs and
make distclean.
Acked-by: Michal Marek <mmarek@suse.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reported-by: Valentin Rothberg <valentinrothberg@gmail.com>
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
There are three usercopy warnings which are currently being silenced for
gcc 4.6 and newer:
1) "copy_from_user() buffer size is too small" compile warning/error
This is a static warning which happens when object size and copy size
are both const, and copy size > object size. I didn't see any false
positives for this one. So the function warning attribute seems to
be working fine here.
Note this scenario is always a bug and so I think it should be
changed to *always* be an error, regardless of
CONFIG_DEBUG_STRICT_USER_COPY_CHECKS.
2) "copy_from_user() buffer size is not provably correct" compile warning
This is another static warning which happens when I enable
__compiletime_object_size() for new compilers (and
CONFIG_DEBUG_STRICT_USER_COPY_CHECKS). It happens when object size
is const, but copy size is *not*. In this case there's no way to
compare the two at build time, so it gives the warning. (Note the
warning is a byproduct of the fact that gcc has no way of knowing
whether the overflow function will be called, so the call isn't dead
code and the warning attribute is activated.)
So this warning seems to only indicate "this is an unusual pattern,
maybe you should check it out" rather than "this is a bug".
I get 102(!) of these warnings with allyesconfig and the
__compiletime_object_size() gcc check removed. I don't know if there
are any real bugs hiding in there, but from looking at a small
sample, I didn't see any. According to Kees, it does sometimes find
real bugs. But the false positive rate seems high.
3) "Buffer overflow detected" runtime warning
This is a runtime warning where object size is const, and copy size >
object size.
All three warnings (both static and runtime) were completely disabled
for gcc 4.6 with the following commit:
2fb0815c9e ("gcc4: disable __compiletime_object_size for GCC 4.6+")
That commit mistakenly assumed that the false positives were caused by a
gcc bug in __compiletime_object_size(). But in fact,
__compiletime_object_size() seems to be working fine. The false
positives were instead triggered by #2 above. (Though I don't have an
explanation for why the warnings supposedly only started showing up in
gcc 4.6.)
So remove warning #2 to get rid of all the false positives, and re-enable
warnings #1 and #3 by reverting the above commit.
Furthermore, since #1 is a real bug which is detected at compile time,
upgrade it to always be an error.
Having done all that, CONFIG_DEBUG_STRICT_USER_COPY_CHECKS is no longer
needed.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David S. Miller
Sudip Mukherjee
Jason A. Donenfeld
Thomas Gleixner
Borislav Petkov
Andreas Platschek
Linus Torvalds
Dave Young
Olof Johansson
Ingo Molnar
Jonathan Corbet
Babu Moger
Paul E. McKenney
Nikolay Borisov
Arnd Bergmann
Valentin Rothberg
Kees Cook
Mauro Carvalho Chehab
Shuah Khan
Uwe Kleine-König
Vivien Didelot
Josh Poimboeuf