07 Feb, 2018
13 commits
-
We get a lot of very large stack frames using gcc-7.0.1 with the default
-fsanitize-address-use-after-scope --param asan-stack=1 options, which can
easily cause an overflow of the kernel stack, e.g.drivers/gpu/drm/i915/gvt/handlers.c:2434:1: warning: the frame size of 46176 bytes is larger than 3072 bytes
drivers/net/wireless/ralink/rt2x00/rt2800lib.c:5650:1: warning: the frame size of 23632 bytes is larger than 3072 bytes
lib/atomic64_test.c:250:1: warning: the frame size of 11200 bytes is larger than 3072 bytes
drivers/gpu/drm/i915/gvt/handlers.c:2621:1: warning: the frame size of 9208 bytes is larger than 3072 bytes
drivers/media/dvb-frontends/stv090x.c:3431:1: warning: the frame size of 6816 bytes is larger than 3072 bytes
fs/fscache/stats.c:287:1: warning: the frame size of 6536 bytes is larger than 3072 bytesTo reduce this risk, -fsanitize-address-use-after-scope is now split out
into a separate CONFIG_KASAN_EXTRA Kconfig option, leading to stack
frames that are smaller than 2 kilobytes most of the time on x86_64. An
earlier version of this patch also prevented combining KASAN_EXTRA with
KASAN_INLINE, but that is no longer necessary with gcc-7.0.1.All patches to get the frame size below 2048 bytes with CONFIG_KASAN=y
and CONFIG_KASAN_EXTRA=n have been merged by maintainers now, so we can
bring back that default now. KASAN_EXTRA=y still causes lots of
warnings but now defaults to !COMPILE_TEST to disable it in
allmodconfig, and it remains disabled in all other defconfigs since it
is a new option. I arbitrarily raise the warning limit for KASAN_EXTRA
to 3072 to reduce the noise, but an allmodconfig kernel still has around
50 warnings on gcc-7.I experimented a bit more with smaller stack frames and have another
follow-up series that reduces the warning limit for 64-bit architectures
to 1280 bytes (without CONFIG_KASAN).With earlier versions of this patch series, I also had patches to address
the warnings we get with KASAN and/or KASAN_EXTRA, using a
"noinline_if_stackbloat" annotation.That annotation now got replaced with a gcc-8 bugfix (see
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715) and a workaround for
older compilers, which means that KASAN_EXTRA is now just as bad as
before and will lead to an instant stack overflow in a few extreme
cases.This reverts parts of commit 3f181b4d8652 ("lib/Kconfig.debug: disable
-Wframe-larger-than warnings with KASAN=y"). Two patches in linux-next
should be merged first to avoid introducing warnings in an allmodconfig
build:
3cd890dbe2a4 ("media: dvb-frontends: fix i2c access helpers for KASAN")
16c3ada89cff ("media: r820t: fix r820t_write_reg for KASAN")Do we really need to backport this?
I think we do: without this patch, enabling KASAN will lead to
unavoidable kernel stack overflow in certain device drivers when built
with gcc-7 or higher on linux-4.10+ or any version that contains a
backport of commit c5caf21ab0cf8. Most people are probably still on
older compilers, but it will get worse over time as they upgrade their
distros.The warnings we get on kernels older than this should all be for code
that uses dangerously large stack frames, though most of them do not
cause an actual stack overflow by themselves.The asan-stack option was
added in linux-4.0, and commit 3f181b4d8652 ("lib/Kconfig.debug:
disable -Wframe-larger-than warnings with KASAN=y") effectively turned
off the warning for allmodconfig kernels, so I would like to see this
fix backported to any kernels later than 4.0.I have done dozens of fixes for individual functions with stack frames
larger than 2048 bytes with asan-stack, and I plan to make sure that
all those fixes make it into the stable kernels as well (most are
already there).Part of the complication here is that asan-stack (from 4.0) was
originally assumed to always require much larger stacks, but that
turned out to be a combination of multiple gcc bugs that we have now
worked around and fixed, but sanitize-address-use-after-scope (from
v4.10) has a much higher inherent stack usage and also suffers from at
least three other problems that we have analyzed but not yet fixed
upstream, each of them makes the stack usage more severe than it should
be.Link: http://lkml.kernel.org/r/20171221134744.2295529-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann
Acked-by: Andrey Ryabinin
Cc: Mauro Carvalho Chehab
Cc: Andrey Ryabinin
Cc: Alexander Potapenko
Cc: Dmitry Vyukov
Cc: Andrey Konovalov
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Similarly to type mismatch checks, new GCC 8.x and Clang also changed for
ABI for returns_nonnull checks. While we can update our code to conform
the new ABI it's more reasonable to just remove it. Because it's just
dead code, we don't have any single user of returns_nonnull attribute in
the whole kernel.And AFAIU the advantage that this attribute could bring would be mitigated
by -fno-delete-null-pointer-checks cflag that we use to build the kernel.
So it's unlikely we will have a lot of returns_nonnull attribute in
future.So let's just remove the code, it has no use.
[aryabinin@virtuozzo.com: fix warning]
Link: http://lkml.kernel.org/r/20180122165711.11510-1-aryabinin@virtuozzo.com
Link: http://lkml.kernel.org/r/20180119152853.16806-2-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin
Cc: Sodagudi Prasad
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Some structure definitions that use macros trip the OPEN_BRACE test.
e.g. +struct bpf_map_def SEC("maps") control_map = {
Improve the test by using $balanced_parens instead of a .*
Miscellanea:
o Use $sline so any comments are ignored
o Correct the message output from declaration to definition
o Remove unnecessary parenthesesLink: http://lkml.kernel.org/r/db9b772999d1d2fbda3b9ee24bbca81a87837e13.1517543491.git.joe@perches.com
Signed-off-by: Joe Perches
Reported-by: Song Liu
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Using an open bracket after what seems to be a declaration can also be a
function definition and declaration argument line continuation so remove
the open bracket from the possible declaration/definition matching.e.g.:
int foobar(int a;
int *b[]);Link: http://lkml.kernel.org/r/1515704479.9619.171.camel@perches.com
Signed-off-by: Joe Perches
Reported-by: Sven Eckelmann
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Greg KH doesn't like this test so exclude the staging directory from the
implied --strict only test unless --strict is actually used on the
command-line.Link: http://lkml.kernel.org/r/1515704034.9619.165.camel@perches.com
Signed-off-by: Joe Perches
Cc: Greg KH
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Declarations should start on a tabstop too.
Link: http://lkml.kernel.org/r/1b5f97673f36595956ad43329f77bf1a5546d2ff.1513976662.git.joe@perches.com
Signed-off-by: Joe Perches
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
DEVICE_ATTR is a declaration macro that has a few alternate and
preferred forms like DEVICE_ATTR_RW, DEVICE_ATTR_RO, and DEVICE_ATTR.As well, many uses of DEVICE_ATTR could use the preferred forms when the
show or store functions are also named in a regular form.Suggest the preferred forms when appropriate.
Also emit a permissions warning if the the permissions are not the
typical 0644, 0444, or 0200.Link: http://lkml.kernel.org/r/725864f363d91d1e1e6894a39fb57662eabd6d65.1513803306.git.joe@perches.com
Signed-off-by: Joe Perches
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Given this patch context,
+#define EFI_ST_DISK_IMG { \
+ 0x00000240, "\xbe\x5b\x7c\xac\x22\xc0\x74\x0b" /* .[|.".t. */ \
+ }the current code misreports a quoted string line continuation defect as
there is a single quote in comment.The 'raw' line should not be tested for quote count, the comment
substituted line should be instead.Link: http://lkml.kernel.org/r/13f2735df10c33ca846e26f42f5cce6618157200.1513698599.git.joe@perches.com
Signed-off-by: Joe Perches
Reported-by: Heinrich Schuchardt
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
module_param and create_proc uses with a permissions use of a single 0 are
"special" and should not emit any warning.module_param uses with permission 0 are not visible in sysfs
create_proc uses with permission 0 use a default permission
Link: http://lkml.kernel.org/r/b6583611bb529ea6f6d43786827fddbabbab0a71.1513190059.git.joe@perches.com
Signed-off-by: Bartosz Golaszewski
Signed-off-by: Joe Perches
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Allow lines with URL to exceed the 80 char limit for improved interaction
in adaption to ongoing but undocumented practice.$ git grep -E '://\S{77}.*' -- '*.[ch]'
As per RFC3986 [1], the URL format allows for alphanum, +, - and .
characters in the scheme before the separator :// as long as it starts
with a letter (e.g. https, git, f.-+).Recognition of URIs without more context information is prone to false
positives and thus currently left out of the heuristics.$rawline is used in the check as comments are removed from $line.
[1] https://tools.ietf.org/html/rfc3986#section-3.1
Link: http://lkml.kernel.org/r/1511355432.12667.15.camel@elementarea.net
Signed-off-by: Andreas Brauchli
Acked-by: Joe Perches
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
clang's AddressSanitizer implementation adds redzones on either side of
alloca()ed buffers. These redzones are 32-byte aligned and at least 32
bytes long.__asan_alloca_poison() is passed the size and address of the allocated
buffer, *excluding* the redzones on either side. The left redzone will
always be to the immediate left of this buffer; but AddressSanitizer may
need to add padding between the end of the buffer and the right redzone.
If there are any 8-byte chunks inside this padding, we should poison
those too.__asan_allocas_unpoison() is just passed the top and bottom of the dynamic
stack area, so unpoisoning is simpler.Link: http://lkml.kernel.org/r/20171204191735.132544-4-paullawrence@google.com
Signed-off-by: Greg Hackmann
Signed-off-by: Paul Lawrence
Acked-by: Andrey Ryabinin
Cc: Alexander Potapenko
Cc: Dmitry Vyukov
Cc: Masahiro Yamada
Cc: Matthias Kaehlcke
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
LLVM doesn't understand GCC-style paramters ("--param asan-foo=bar"), thus
we currently we don't use inline/globals/stack instrumentation when
building the kernel with clang.Add support for LLVM-style parameters ("-mllvm -asan-foo=bar") to enable
all KASAN features.Link: http://lkml.kernel.org/r/20171204191735.132544-3-paullawrence@google.com
Signed-off-by: Andrey Ryabinin
Signed-off-by: Paul Lawrence
Reviewed-by: Alexander Potapenko
Cc: Dmitry Vyukov
Cc: Greg Hackmann
Cc: Masahiro Yamada
Cc: Matthias Kaehlcke
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
With KASAN enabled the kernel has two different memset() functions, one
with KASAN checks (memset) and one without (__memset). KASAN uses some
macro tricks to use the proper version where required. For example
memset() calls in mm/slub.c are without KASAN checks, since they operate
on poisoned slab object metadata.The issue is that clang emits memset() calls even when there is no
memset() in the source code. They get linked with improper memset()
implementation and the kernel fails to boot due to a huge amount of KASAN
reports during early boot stages.The solution is to add -fno-builtin flag for files with KASAN_SANITIZE :=
n marker.Link: http://lkml.kernel.org/r/8ffecfffe04088c52c42b92739c2bd8a0bcb3f5e.1516384594.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov
Acked-by: Nick Desaulniers
Cc: Masahiro Yamada
Cc: Michal Marek
Cc: Andrey Ryabinin
Cc: Alexander Potapenko
Cc: Dmitry Vyukov
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Feb, 2018
5 commits
-
Pull printk updates from Petr Mladek:
- Add a console_msg_format command line option:
The value "default" keeps the old "[time stamp] text\n" format. The
value "syslog" allows to see the syslog-like "[timestamp] text" format.This feature was requested by people doing regression tests, for
example, 0day robot. They want to have both filtered and full logs
at hands.- Reduce the risk of softlockup:
Pass the console owner in a busy loop.
This is a new approach to the old problem. It was first proposed by
Steven Rostedt on Kernel Summit 2017. It marks a context in which
the console_lock owner calls console drivers and could not sleep.
On the other side, printk() callers could detect this state and use
a busy wait instead of a simple console_trylock(). Finally, the
console_lock owner checks if there is a busy waiter at the end of
the special context and eventually passes the console_lock to the
waiter.The hand-off works surprisingly well and helps in many situations.
Well, there is still a possibility of the softlockup, for example,
when the flood of messages stops and the last owner still has too
much to flush.There is increasing number of people having problems with
printk-related softlockups. We might eventually need to get better
solution. Anyway, this looks like a good start and promising
direction.- Do not allow to schedule in console_unlock() called from printk():
This reverts an older controversial commit. The reschedule helped
to avoid softlockups. But it also slowed down the console output.
This patch is obsoleted by the new console waiter logic described
above. In fact, the reschedule made the hand-off less effective.- Deprecate "%pf" and "%pF" format specifier:
It was needed on ia64, ppc64 and parisc64 to dereference function
descriptors and show the real function address. It is done
transparently by "%ps" and "pS" format specifier now.Sergey Senozhatsky found that all the function descriptors were in
a special elf section and could be easily detected.- Remove printk_symbol() API:
It has been obsoleted by "%pS" format specifier, and this change
helped to remove few continuous lines and a less intuitive old API.- Remove redundant memsets:
Sergey removed unnecessary memset when processing printk.devkmsg
command line option.* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (27 commits)
printk: drop redundant devkmsg_log_str memsets
printk: Never set console_may_schedule in console_trylock()
printk: Hide console waiter logic into helpers
printk: Add console owner and waiter logic to load balance console writes
kallsyms: remove print_symbol() function
checkpatch: add pF/pf deprecation warning
symbol lookup: introduce dereference_symbol_descriptor()
parisc64: Add .opd based function descriptor dereference
powerpc64: Add .opd based function descriptor dereference
ia64: Add .opd based function descriptor dereference
sections: split dereference_function_descriptor()
openrisc: Fix conflicting types for _exext and _stext
lib: do not use print_symbol()
irq debug: do not use print_symbol()
sysfs: do not use print_symbol()
drivers: do not use print_symbol()
x86: do not use print_symbol()
unicore32: do not use print_symbol()
sh: do not use print_symbol()
mn10300: do not use print_symbol()
... -
Pull Kconfig updates from Masahiro Yamada:
"A pretty big batch of Kconfig updates.I have to mention the lexer and parser of Kconfig are now built from
real .l and .y sources. So, flex and bison are the requirement for
building the kernel. Both of them (unlike gperf) have been stable for
a long time. This change has been tested several weeks in linux-next,
and I did not receive any problem report about this.Summary:
- add checks for mistakes, like the choice default is not in choice,
help is doubled- document data structure and complex code
- fix various memory leaks
- change Makefile to build lexer and parser instead of using
pre-generated C files- drop 'boolean' keyword, which is equivalent to 'bool'
- use default 'yy' prefix and remove unneeded Make variables
- fix gettext() check for xconfig
- announce that oldnoconfig will be finally removed
- make 'Selected by:' and 'Implied by' readable in help and search
result- hide silentoldconfig from 'make help' to stop confusing people
- fix misc things and cleanups"
* tag 'kconfig-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (37 commits)
kconfig: Remove silentoldconfig from help and docs; fix kconfig/conf's help
kconfig: make "Selected by:" and "Implied by:" readable
kconfig: announce removal of oldnoconfig if used
kconfig: fix make xconfig when gettext is missing
kconfig: Clarify menu and 'if' dependency propagation
kconfig: Document 'if' flattening logic
kconfig: Clarify choice dependency propagation
kconfig: Document SYMBOL_OPTIONAL logic
kbuild: remove unnecessary LEX_PREFIX and YACC_PREFIX
kconfig: use default 'yy' prefix for lexer and parser
kconfig: make conf_unsaved a local variable of conf_read()
kconfig: make xfgets() really static
kconfig: make input_mode static
kconfig: Warn if there is more than one help text
kconfig: drop 'boolean' keyword
kconfig: use bool instead of boolean for type definition attributes, again
kconfig: Remove menu_end_entry()
kconfig: Document important expression functions
kconfig: Document automatic submenu creation code
kconfig: Fix choice symbol expression leak
... -
…asahiroy/linux-kbuild
Pull Kbuild misc updates from Masahiro Yamada:
- add snap-pkg target to create Linux kernel snap package
- make out-of-tree creation of source packages fail correctly
- improve and fix several semantic patches
* tag 'kbuild-misc-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
Coccinelle: coccicheck: fix typo
Coccinelle: memdup: drop spurious line
Coccinelle: kzalloc-simple: Rename kzalloc-simple to zalloc-simple
Coccinelle: ifnullfree: Trim the warning reported in report mode
Coccinelle: alloc_cast: Add more memory allocating functions to the list
Coccinelle: array_size: report even if include is missing
Coccinelle: kzalloc-simple: Add all zero allocating functions
kbuild: pkg: make out-of-tree rpm/deb-pkg build immediately fail
scripts/package: snap-pkg target -
Pull Kbuild updates from Masahiro Yamada:
- terminate the build correctly in case of fixdep errors
- clean up fixdep
- suppress packed-not-aligned warnings from GCC-8
- fix W= handling for extra DTC warnings
* tag 'kbuild-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: fix W= option checks for extra DTC warnings
Kbuild: suppress packed-not-aligned warning for default setting only
fixdep: use existing helper to check modular CONFIG options
fixdep: refactor parse_dep_file()
fixdep: move global variables to local variables of main()
fixdep: remove unneeded memcpy() in parse_dep_file()
fixdep: factor out common code for reading files
fixdep: use malloc() and read() to load dep_file to buffer
fixdep: remove unnecessary inclusion
fixdep: exit with error code in error branches of do_config_file() -
Pull char/misc driver updates from Greg KH:
"Here is the big pull request for char/misc drivers for 4.16-rc1.There's a lot of stuff in here. Three new driver subsystems were added
for various types of hardware busses:- siox
- slimbus
- soundwireas well as a new vboxguest subsystem for the VirtualBox hypervisor
drivers.There's also big updates from the FPGA subsystem, lots of Android
binder fixes, the usual handful of hyper-v updates, and lots of other
smaller driver updates.All of these have been in linux-next for a long time, with no reported
issues"* tag 'char-misc-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (155 commits)
char: lp: use true or false for boolean values
android: binder: use VM_ALLOC to get vm area
android: binder: Use true and false for boolean values
lkdtm: fix handle_irq_event symbol for INT_HW_IRQ_EN
EISA: Delete error message for a failed memory allocation in eisa_probe()
EISA: Whitespace cleanup
misc: remove AVR32 dependencies
virt: vbox: Add error mapping for VERR_INVALID_NAME and VERR_NO_MORE_FILES
soundwire: Fix a signedness bug
uio_hv_generic: fix new type mismatch warnings
uio_hv_generic: fix type mismatch warnings
auxdisplay: img-ascii-lcd: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE
uio_hv_generic: add rescind support
uio_hv_generic: check that host supports monitor page
uio_hv_generic: create send and receive buffers
uio: document uio_hv_generic regions
doc: fix documentation about uio_hv_generic
vmbus: add monitor_id and subchannel_id to sysfs per channel
vmbus: fix ABI documentation
uio_hv_generic: use ISR callback method
...
01 Feb, 2018
4 commits
-
Correct spelling of "coccinelle".
Signed-off-by: Julia Lawall
Signed-off-by: Masahiro Yamada -
Pull documentation updates from Jonathan Corbet:
"Documentation updates for 4.16.New stuff includes refcount_t documentation, errseq documentation,
kernel-doc support for nested structure definitions, the removal of
lots of crufty kernel-doc support for unused formats, SPDX tag
documentation, the beginnings of a manual for subsystem maintainers,
and lots of fixes and updates.As usual, some of the changesets reach outside of Documentation/ to
effect kerneldoc comment fixes. It also adds the new LICENSES
directory, of which Thomas promises I do not need to be the
maintainer"* tag 'docs-4.16' of git://git.lwn.net/linux: (65 commits)
linux-next: docs-rst: Fix typos in kfigure.py
linux-next: DOC: HWPOISON: Fix path to debugfs in hwpoison.txt
Documentation: Fix misconversion of #if
docs: add index entry for networking/msg_zerocopy
Documentation: security/credentials.rst: explain need to sort group_list
LICENSES: Add MPL-1.1 license
LICENSES: Add the GPL 1.0 license
LICENSES: Add Linux syscall note exception
LICENSES: Add the MIT license
LICENSES: Add the BSD-3-clause "Clear" license
LICENSES: Add the BSD 3-clause "New" or "Revised" License
LICENSES: Add the BSD 2-clause "Simplified" license
LICENSES: Add the LGPL-2.1 license
LICENSES: Add the LGPL 2.0 license
LICENSES: Add the GPL 2.0 license
Documentation: Add license-rules.rst to describe how to properly identify file licenses
scripts: kernel_doc: better handle show warnings logic
fs/*/Kconfig: drop links to 404-compliant http://acl.bestbits.at
doc: md: Fix a file name to md-fault.c in fault-injection.txt
errseq: Add to documentation tree
... -
The current find done in find_other_sources() excludes directories in
the kernel tree that are named 'include', eg.:./security/apparmor/include
./security/selinux/include
./drivers/net/wireless/broadcom/brcm80211/include
./drivers/gpu/drm/amd/acp/include
./drivers/gpu/drm/amd/display/include
./drivers/gpu/drm/amd/include
./drivers/gpu/drm/nouveau/includeThis changes the find command in find_other_sources() to include those
using the -path option.Link: http://lkml.kernel.org/r/1513335768-7852-1-git-send-email-arend.vanspriel@broadcom.com
Signed-off-by: Arend van Spriel
Cc: Robert Jarzmik
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In case of running scripts/decodecode without any parameters in order to
give a copy'n'pasted Code line from, for example, email it would parse
only first line of it, while in emails it's split to few.ie, when you have a file out of oops the Code line looks like
Code: hh hh ... ... hh\n
When copy'n'paste from, for example, email where sender or some middle
MTA split it, the line looks like:Code: hh hh ... hh\n
hh ... ... hh\n
hh hh ... hh\nThe Code line followed by another oops line usually contains characters
out of hex digit + space + < + > set.So add logic to join this split back if and only if the following lines
have hex digits, or spaces, or '' characters. It will be quite
unlikely to have a broken input in well formed Oops or dmesg, thus a
simple regex is being used.Link: http://lkml.kernel.org/r/20171212100323.33201-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko
Cc: Will Deacon
Cc: Dave Martin
Cc: Philippe Ombredanne
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
31 Jan, 2018
1 commit
-
Pull RCU updates from Ingo Molnar:
"The main RCU changes in this cycle were:- Updates to use cond_resched() instead of cond_resched_rcu_qs()
where feasible (currently everywhere except in kernel/rcu and in
kernel/torture.c). Also a couple of fixes to avoid sending IPIs to
offline CPUs.- Updates to simplify RCU's dyntick-idle handling.
- Updates to remove almost all uses of smp_read_barrier_depends() and
read_barrier_depends().- Torture-test updates.
- Miscellaneous fixes"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits)
torture: Save a line in stutter_wait(): while -> for
torture: Eliminate torture_runnable and perf_runnable
torture: Make stutter less vulnerable to compilers and races
locking/locktorture: Fix num reader/writer corner cases
locking/locktorture: Fix rwsem reader_delay
torture: Place all torture-test modules in one MAINTAINERS group
rcutorture/kvm-build.sh: Skip build directory check
rcutorture: Simplify functions.sh include path
rcutorture: Simplify logging
rcutorture/kvm-recheck-*: Improve result directory readability check
rcutorture/kvm.sh: Support execution from any directory
rcutorture/kvm.sh: Use consistent help text for --qemu-args
rcutorture/kvm.sh: Remove unused variable, `alldone`
rcutorture: Remove unused script, config2frag.sh
rcutorture/configinit: Fix build directory error message
rcutorture: Preempt RCU-preempt readers more vigorously
torture: Reduce #ifdefs for preempt_schedule()
rcu: Remove have_rcu_nocb_mask from tree_plugin.h
rcu: Add comment giving debug strategy for double call_rcu()
tracing, rcu: Hide trace event rcu_nocb_wake when not used
...
30 Jan, 2018
1 commit
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Pull x86/pti updates from Thomas Gleixner:
"Another set of melted spectrum related changes:- Code simplifications and cleanups for RSB and retpolines.
- Make the indirect calls in KVM speculation safe.
- Whitelist CPUs which are known not to speculate from Meltdown and
prepare for the new CPUID flag which tells the kernel that a CPU is
not affected.- A less rigorous variant of the module retpoline check which merily
warns when a non-retpoline protected module is loaded and reflects
that fact in the sysfs file.- Prepare for Indirect Branch Prediction Barrier support.
- Prepare for exposure of the Speculation Control MSRs to guests, so
guest OSes which depend on those "features" can use them. Includes
a blacklist of the broken microcodes. The actual exposure of the
MSRs through KVM is still being worked on"* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/speculation: Simplify indirect_branch_prediction_barrier()
x86/retpoline: Simplify vmexit_fill_RSB()
x86/cpufeatures: Clean up Spectre v2 related CPUID flags
x86/cpu/bugs: Make retpoline module warning conditional
x86/bugs: Drop one "mitigation" from dmesg
x86/nospec: Fix header guards names
x86/alternative: Print unadorned pointers
x86/speculation: Add basic IBPB (Indirect Branch Prediction Barrier) support
x86/cpufeature: Blacklist SPEC_CTRL/PRED_CMD on early Spectre v2 microcodes
x86/pti: Do not enable PTI on CPUs which are not vulnerable to Meltdown
x86/msr: Add definitions for new speculation control MSRs
x86/cpufeatures: Add AMD feature bits for Speculation Control
x86/cpufeatures: Add Intel feature bits for Speculation Control
x86/cpufeatures: Add CPUID_7_EDX CPUID leaf
module/retpoline: Warn about missing retpoline in module
KVM: VMX: Make indirect call speculation safe
KVM: x86: Make indirect calls in emulator speculation safe
29 Jan, 2018
1 commit
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The kmemdup line in the non-patch case was left over from the added kmemdup
line in the patch case.Signed-off-by: Julia Lawall
Signed-off-by: Masahiro Yamada
28 Jan, 2018
1 commit
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As explained by Michal Marek at https://lkml.org/lkml/2011/8/31/189
silentoldconfig has become a misnomer. It has become an internal interface
so remove it from "make help" and Documentation/ to stop confusing people
using it as seen for instance at
https://chromium-review.googlesource.com/835632 Don't remove it from
kconfig/Makefile yet not to break any (other) tool using it.On the other hand, correct and expand its description in the help of
the (internal) scripts/kconfig/conf.cSigned-off-by: Marc Herbert
Signed-off-by: Masahiro Yamada
26 Jan, 2018
1 commit
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There's a risk that a kernel which has full retpoline mitigations becomes
vulnerable when a module gets loaded that hasn't been compiled with the
right compiler or the right option.To enable detection of that mismatch at module load time, add a module info
string "retpoline" at build time when the module was compiled with
retpoline support. This only covers compiled C source, but assembler source
or prebuilt object files are not checked.If a retpoline enabled kernel detects a non retpoline protected module at
load time, print a warning and report it in the sysfs vulnerability file.[ tglx: Massaged changelog ]
Signed-off-by: Andi Kleen
Signed-off-by: Thomas Gleixner
Cc: David Woodhouse
Cc: gregkh@linuxfoundation.org
Cc: torvalds@linux-foundation.org
Cc: jeyu@kernel.org
Cc: arjan@linux.intel.com
Link: https://lkml.kernel.org/r/20180125235028.31211-1-andi@firstfloor.org
25 Jan, 2018
3 commits
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Kbuild supports 3 levels of extra warnings, and multiple levels can
be combined, like W=12, W=123. It was added by commit a6de553da01c
("kbuild: Allow to combine multiple W= levels").From the log of commit 8654cb8d0371 ("dtc: update warning settings
for new bus and node/property name checks"), I assume:- unit_address_vs_reg, simple_bus_reg, etc. belong to level 1
- node_name_chars_strict, property_name_chars_strict belong to level 2However, the level 1 warnings are displayed by any argument to W=.
On the other hand, the level 2 warnings are displayed by W=2, but
not by W=12, or W=123.Use $(findstring ...) like scripts/Makefile.extrawarn.
Signed-off-by: Masahiro Yamada
Acked-by: Arnd Bergmann -
Reverse dependency expressions can get rather unwieldy, especially if
a symbol is selected by more than a handful of other symbols. I.e. it's
possible to have near endless expressions like:
A && B && !C || D || F && (G || H) || [...]Chop these expressions into actually readable chunks:
- A && B && !C
- D
- F && (G || H)
- [...]I.e. transform the top level OR tokens into newlines and prepend each
line with a minus. This makes the "Selected by:" and "Implied by:" blurb
much easier to read. This is done only if there is more than one top
level OR. "Depends on:" and "Range :" were deliberately left as they are.Based on idea from Paul Bolle.
Suggested-by: Paul Bolle
Signed-off-by: Petr Vorel
Signed-off-by: Masahiro Yamada -
The 'oldnoconfig' is really confusing due to its counter-intuitive name.
It was renamed by commit fb16d8912db5 ("kconfig: replace 'oldnoconfig'
with 'olddefconfig', and keep the old name as an alias").The 'oldnoconfig' has been kept as an alias for enough period of time,
and finally I am planning to remove it. I will give people a little
more time for migration. Meanwhile, the following message will be
displayed if oldnoconfig is used.WARNING: "oldnoconfig" target will be removed after Linux 4.19
Please use "olddefconfig" instead, which is an alias.Signed-off-by: Masahiro Yamada
Reviewed-by: Ulf Magnusson
22 Jan, 2018
3 commits
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The C-based config programs are properly guarded from a missing (or,
currently, external) libintl.h by the HOST_EXTRACFLAGS check, but
this does not help the C++-based qconf.Signed-off-by: Yaakov Selkowitz
Signed-off-by: Masahiro Yamada -
It is not obvious that the last two cases refer to menus and ifs,
respectively, in the conditional that sets 'parentdep'.Automatic submenu creation is done later, so the parent can't be a
symbol here.No functional changes. Only comments added.
Signed-off-by: Ulf Magnusson
Signed-off-by: Masahiro Yamada -
It is not obvious that this might refer to an 'if', making the code
pretty cryptic:if (menu->list && (!menu->prompt || !menu->prompt->text)) {
Kconfig keeps the 'if' menu nodes even after flattening. Reflect that in
the example to be accurate.No functional changes. Only comments added.
Signed-off-by: Ulf Magnusson
Signed-off-by: Masahiro Yamada
21 Jan, 2018
7 commits
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It's easy to miss that choices are special-cased to pass on their mode
as the parent dependency.No functional changes. Only comments added.
Signed-off-by: Ulf Magnusson
Signed-off-by: Masahiro Yamada -
Not obvious, especially if you don't already know how choices are
implemented.No functional changes. Only comments added.
Signed-off-by: Ulf Magnusson
Signed-off-by: Masahiro Yamada -
Kconfig was the only user of these. With Kconfig converted to use
the default 'yy' prefix, we do not need them any more.Signed-off-by: Masahiro Yamada
Reviewed-by: Ulf Magnusson -
Flex and Bison provide an option to change the prefix of globally-
visible symbols. This is useful to link multiple lexers and/or
parsers into the same executable. However, Kconfig (and any other
host programs in kernel) uses a single lexer and parser. I do not
see a good reason to change the default 'yy' prefix.Signed-off-by: Masahiro Yamada
Reviewed-by: Ulf Magnusson -
conf_unsaved is initialized by conf_read_simple(), but it is possible
to move it to conf_read() so that it can be a local variable.Signed-off-by: Masahiro Yamada
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Sparse reports:
warning: symbol 'xfgets' was not declared. Should it be static?It is declared as static, but it is missing in the definition part.
Move the definition up and remove the forward declaration.Signed-off-by: Masahiro Yamada
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Sparse reports:
warning: symbol 'input_mode' was not declared. Should it be static?Signed-off-by: Masahiro Yamada