Pull x86 asm updates from Ingo Molnar:
- Introduce the ORC unwinder, which can be enabled via
CONFIG_ORC_UNWINDER=y.
The ORC unwinder is a lightweight, Linux kernel specific debuginfo
implementation, which aims to be DWARF done right for unwinding.
Objtool is used to generate the ORC unwinder tables during build, so
the data format is flexible and kernel internal: there's no
dependency on debuginfo created by an external toolchain.
The ORC unwinder is almost two orders of magnitude faster than the
(out of tree) DWARF unwinder - which is important for perf call graph
profiling. It is also significantly simpler and is coded defensively:
there has not been a single ORC related kernel crash so far, even
with early versions. (knock on wood!)
But the main advantage is that enabling the ORC unwinder allows
CONFIG_FRAME_POINTERS to be turned off - which speeds up the kernel
measurably:
With frame pointers disabled, GCC does not have to add frame pointer
instrumentation code to every function in the kernel. The kernel's
.text size decreases by about 3.2%, resulting in better cache
utilization and fewer instructions executed, resulting in a broad
kernel-wide speedup. Average speedup of system calls should be
roughly in the 1-3% range - measurements by Mel Gorman [1] have shown
a speedup of 5-10% for some function execution intense workloads.
The main cost of the unwinder is that the unwinder data has to be
stored in RAM: the memory cost is 2-4MB of RAM, depending on kernel
config - which is a modest cost on modern x86 systems.
Given how young the ORC unwinder code is it's not enabled by default
- but given the performance advantages the plan is to eventually make
it the default unwinder on x86.
See Documentation/x86/orc-unwinder.txt for more details.
- Remove lguest support: its intended role was that of a temporary
proof of concept for virtualization, plus its removal will enable the
reduction (removal) of the paravirt API as well, so Rusty agreed to
its removal. (Juergen Gross)
- Clean up and fix FSGS related functionality (Andy Lutomirski)
- Clean up IO access APIs (Andy Shevchenko)
- Enhance the symbol namespace (Jiri Slaby)
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits)
objtool: Handle GCC stack pointer adjustment bug
x86/entry/64: Use ENTRY() instead of ALIGN+GLOBAL for stub32_clone()
x86/fpu/math-emu: Add ENDPROC to functions
x86/boot/64: Extract efi_pe_entry() from startup_64()
x86/boot/32: Extract efi_pe_entry() from startup_32()
x86/lguest: Remove lguest support
x86/paravirt/xen: Remove xen_patch()
objtool: Fix objtool fallthrough detection with function padding
x86/xen/64: Fix the reported SS and CS in SYSCALL
objtool: Track DRAP separately from callee-saved registers
objtool: Fix validate_branch() return codes
x86: Clarify/fix no-op barriers for text_poke_bp()
x86/switch_to/64: Rewrite FS/GS switching yet again to fix AMD CPUs
selftests/x86/fsgsbase: Test selectors 1, 2, and 3
x86/fsgsbase/64: Report FSBASE and GSBASE correctly in core dumps
x86/fsgsbase/64: Fully initialize FS and GS state in start_thread_common
x86/asm: Fix UNWIND_HINT_REGS macro for older binutils
x86/asm/32: Fix regs_get_register() on segment registers
x86/xen/64: Rearrange the SYSCALL entries
x86/asm/32: Remove a bunch of '& 0xffff' from pt_regs segment reads
...
Pull documentation updates from Jonathan Corbet:
"After a fair amount of churn in the last couple of cycles, docs are
taking it easier this time around. Lots of fixes and some new
documentation, but nothing all that radical. Perhaps the most
interesting change for many is the scripts/sphinx-pre-install tool
from Mauro; it will tell you exactly which packages you need to
install to get a working docs toolchain on your system.
There are two little patches reaching outside of Documentation/; both
just tweak kerneldoc comments to eliminate warnings and fix some
dangling doc pointers"
* 'docs-next' of git://git.lwn.net/linux: (52 commits)
Documentation/sphinx: fix kernel-doc decode for non-utf-8 locale
genalloc: Fix an incorrect kerneldoc comment
doc: Add documentation for the genalloc subsystem
assoc_array: fix path to assoc_array documentation
kernel-doc parser mishandles declarations split into lines
docs: ReSTify table of contents in core.rst
docs: process: drop git snapshots from applying-patches.rst
Documentation:input: fix typo
swap: Remove obsolete sentence
sphinx.rst: Allow Sphinx version 1.6 at the docs
docs-rst: fix verbatim font size on tables
Documentation: stable-kernel-rules: fix broken git urls
rtmutex: update rt-mutex
rtmutex: update rt-mutex-design
docs: fix minimal sphinx version in conf.py
docs: fix nested numbering in the TOC
NVMEM documentation fix: A minor typo
docs-rst: pdf: use same vertical margin on all Sphinx versions
doc: Makefile: if sphinx is not found, run a check script
docs: Fix paths in security/keys
...
dtc uses an incorrect format specifier for printing a uint64_t value.
uint64_t may be either 'unsigned long' or 'unsigned long long' depending
on the host architecture.
Fix this by using %llx and casting to unsigned long long, which ensures
that we always have a wide enough variable to print 64 bits of hex.
HOSTCC scripts/dtc/checks.o
scripts/dtc/checks.c: In function 'check_simple_bus_reg':
scripts/dtc/checks.c:876:2: warning: format '%zx' expects argument of type 'size_t', but argument 4 has type 'uint64_t' [-Wformat=]
snprintf(unit_addr, sizeof(unit_addr), "%zx", reg);
^
scripts/dtc/checks.c:876:2: warning: format '%zx' expects argument of type 'size_t', but argument 4 has type 'uint64_t' [-Wformat=]
Link: http://lkml.kernel.org/r/20170829222034.GJ20805@n2100.armlinux.org.uk
Fixes: 828d4cdd01 ("dtc: check.c fix compile error")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported by Johannes Berg [1]. Problem here: function
process_proto_type() concatenates the striped lines of declaration
without any whitespace. A one-liner of::
struct something {
struct foo
bar;
};
has to be::
struct something {struct foo bar;};
Without the patching process_proto_type(), the result missed the space
between 'foo' and 'bar'::
struct something {struct foobar;};
Bugfix of process_proto_type() brings next error when blank lines
between enum declaration::
warning: Enum value ' ' not described in enum 'foo'
Problem here: dump_enum() does not strip leading whitespaces from
the concatenated string (with the new additional space from
process_proto_type).
[1] https://www.mail-archive.com/linux-doc@vger.kernel.org/msg12410.html
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Pull Kbuild fixes from Masahiro Yamada:
- fix linker script regression caused by dead code elimination support
- fix typos and outdated comments
- specify kselftest-clean as a PHONY target
- fix "make dtbs_install" when $(srctree) includes shell special
characters like '~'
- Move -fshort-wchar to the global option list because defining it
partially emits warnings
* tag 'kbuild-fixes-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: update comments of Makefile.asm-generic
kbuild: Do not use hyphen in exported variable name
Makefile: add kselftest-clean to PHONY target list
Kbuild: use -fshort-wchar globally
fixdep: trivial: typo fix and correction
kbuild: trivial cleanups on the comments
kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured
This definition in Makefile.dtbinst:
export dtbinst-root ?= $(obj)
should define and export dtbinst-root when handling the root dts
directory, and do nothing in the subdirectories. However some shells,
including dash, will not pass through environment variables whose name
includes a hyphen. Usually GNU make does not use a shell to recurse,
but if e.g. $(srctree) contains '~' it will use a shell here.
Rename the variable to dtbinst_root.
References: https://bugs.debian.org/833561
Fixes: 323a028d39cdi ("dts, kbuild: Implement support for dtb vendor subdirs")
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Allow any number of command line arguments to match either the
section header or the section contents and create new files.
Create MAINTAINERS.new and SECTION.new.
This allows scripting of the movement of various sections from
MAINTAINERS.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Instead of reading STDIN and writing STDOUT, use specific filenames of
MAINTAINERS and MAINTAINERS.new.
Use hash references instead of global hash %hash so future modifications
can read and write specific hashes to split up MAINTAINERS into multiple
files using a script.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Section [A-Z]: patterns are not currently in any required sorting order.
Add a specific sorting sequence to MAINTAINERS entries.
Sort F: and X: patterns in alphabetic order.
The preferred section ordering is:
SECTION HEADER
M: Maintainers
R: Reviewers
P: Named persons without email addresses
L: Mailing list addresses
S: Status of this section (Supported, Maintained, Orphan, etc...)
W: Any relevant URLs
T: Source code control type (git, quilt, etc)
Q: Patchwork patch acceptance queue site
B: Bug tracking URIs
C: Chat URIs
F: Files with wildcard patterns (alphabetic ordered)
X: Excluded files with wildcard patterns (alphabetic ordered)
N: Files with regex patterns
K: Keyword regexes in source code for maintainership identification
Miscellaneous perl neatening:
- Rename %map to %hash, map has a different meaning in perl
- Avoid using \& and local variables for function indirection
- Use return for a little c like clarity
- Use c-like function call style instead of &function
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow for MAINTAINERS to become a directory and if it is,
read all the files in the directory for maintained sections.
Optionally look for all files named MAINTAINERS in directories
excluding the .git directory by using --find-maintainer-files.
This optional feature adds ~.3 seconds of CPU on an Intel
i5-6200 with an SSD.
Miscellanea:
- Create a read_maintainer_file subroutine from the existing code
- Test only the existence of MAINTAINERS, not whether it's a file
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
RHEL 7.x and clone distros are shipped with Sphinx 1.1.x,
with is incompatible with Kernel ReST markups.
So, on those systems, the only alternative is to install
it via a Python virtual environment.
While seeking for "pip" on CentOS 7.3, I noticed that it
is not really needed, as python-virtualenv has its version
packaged there already. So, remove this from the list of
requirements for all distributions.
With regards to PDF, we need at least texlive-tabulary
extension, but that is not shipped there (at least on
CentOS). So, disable PDF packages as a whole.
Please notice, however, that texlive + amsmath is needed for
ReST to properly handle ReST ".. math::" tags. Yet, Sphinx
fall back to display the LaTeX math expressions as-is, if
such extension is not available.
So, let's just disable all texlive packages as a whole.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Pull DeviceTree fixes from Rob Herring:
"Two small DT fixes:
- Fix error handling in of_irq_to_resource_table() due to
of_irq_to_resource() error return changes.
- Fix dtx_diff script due to dts include path changes"
* tag 'devicetree-fixes-for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
of: irq: fix of_irq_to_resource() error check
scripts/dtc: dtx_diff - update include dts paths to match build
Add the new ORC unwinder which is enabled by CONFIG_ORC_UNWINDER=y.
It plugs into the existing x86 unwinder framework.
It relies on objtool to generate the needed .orc_unwind and
.orc_unwind_ip sections.
For more details on why ORC is used instead of DWARF, see
Documentation/x86/orc-unwinder.txt - but the short version is
that it's a simplified, fundamentally more robust debugninfo
data structure, which also allows up to two orders of magnitude
faster lookups than the DWARF unwinder - which matters to
profiling workloads like perf.
Thanks to Andy Lutomirski for the performance improvement ideas:
splitting the ORC unwind table into two parallel arrays and creating a
fast lookup table to search a subset of the unwind table.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/0a6cbfb40f8da99b7a45a1a8302dc6aef16ec812.1500938583.git.jpoimboe@redhat.com
[ Extended the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Objtool tries to silence 'unreachable instruction' warnings when it
detects gcov is enabled, because gcov produces a lot of unreachable
instructions and they don't really matter.
However, the 0-day bot is still reporting some unreachable instruction
warnings with CONFIG_GCOV_KERNEL=y on GCC 4.6.4.
As it turns out, objtool's gcov detection doesn't work with older
versions of GCC because they don't create a bunch of symbols with the
'gcov.' prefix like newer versions of GCC do.
Move the gcov check out of objtool and instead just create a new
'--no-unreachable' flag which can be passed in by the kernel Makefile
when CONFIG_GCOV_KERNEL is defined.
Also rename the 'nofp' variable to 'no_fp' for consistency with the new
'no_unreachable' variable.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 9cfffb1168 ("objtool: Skip all "unreachable instruction" warnings for gcov kernels")
Link: http://lkml.kernel.org/r/c243dc78eb2ffdabb6e927844dea39b6033cd395.1500939244.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This adds a perl script to actually parse the MAINTAINERS file, clean up
some whitespace in it, warn about errors in it, and then properly sort
the end result.
My perl-fu is atrocious, so the script has basically been created by
randomly putting various characters in a pile, mixing them around, and
then looking it the end result does anything interesting when used as a
perl script.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for detecting and installing missing packages
on Mageia. I opted to use "urpmi" at the install instructions,
as this is present on Mageia since ever. Yet, if I were using
Mageia 6, I would likely be using "dnf", as it is, IMHO,
easier to use.
Tested with Mageia 6.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Gentoo need some USE for GraphViz and ImageMagick to have
the features required by kfigure.py.
Output that when providing instructions for Gentoo.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
ImageMagick actually uses librsvg for conversions when converiting
from SVG (actually, it uses rsvg-convert). That causes the build to
fail with:
WARNING: Error #1 when calling: /usr/bin/convert /home/mchehab/docs/Documentation/media/uapi/v4l/selection.svg /home/mchehab/docs/Documentation/output/latex/selection.pdf
convert: delegate failed `'rsvg-convert' -o '%o' '%i'' @ error/delegate.c/InvokeDelegate/1919.
convert: unable to open file `/tmp/magick-8883oOQfHzrA5trM': No such file or directory @ error/constitute.c/ReadImage/544.
Add the corresponding dependencies.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
On newer versions of graphviz packaging on Fedora, it is needed to
install a separate package for PDF support.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Instead of using 3 commands to install a virtualenv, use
a single one, reading the requirements from this file:
Documentation/sphinx/requirements.txt
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Detect if the script runs after creating the virtualenv,
printing the command line commands to enable the virtualenv.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
