Commit Graph

4783 Commits

Author SHA1 Message Date
Linus Torvalds
70ad6368e8 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
 "The biggest part is a series of reverts for the macro based GCC
  inlining workarounds. It caused regressions in distro build and other
  kernel tooling environments, and the GCC project was very receptive to
  fixing the underlying inliner weaknesses - so as time ran out we
  decided to do a reasonably straightforward revert of the patches. The
  plan is to rely on the 'asm inline' GCC 9 feature, which might be
  backported to GCC 8 and could thus become reasonably widely available
  on modern distros.

  Other than those reverts, there's misc fixes from all around the
  place.

  I wish our final x86 pull request for v4.20 was smaller..."

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs"
  Revert "x86/objtool: Use asm macros to work around GCC inlining bugs"
  Revert "x86/refcount: Work around GCC inlining bug"
  Revert "x86/alternatives: Macrofy lock prefixes to work around GCC inlining bugs"
  Revert "x86/bug: Macrofy the BUG table section handling, to work around GCC inlining bugs"
  Revert "x86/paravirt: Work around GCC inlining bugs when compiling paravirt ops"
  Revert "x86/extable: Macrofy inline assembly code to work around GCC inlining bugs"
  Revert "x86/cpufeature: Macrofy inline assembly code to work around GCC inlining bugs"
  Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"
  x86/mtrr: Don't copy uninitialized gentry fields back to userspace
  x86/fsgsbase/64: Fix the base write helper functions
  x86/mm/cpa: Fix cpa_flush_array() TLB invalidation
  x86/vdso: Pass --eh-frame-hdr to the linker
  x86/mm: Fix decoy address handling vs 32-bit builds
  x86/intel_rdt: Ensure a CPU remains online for the region's pseudo-locking sequence
  x86/dump_pagetables: Fix LDT remap address marker
  x86/mm: Fix guard hole handling
2018-12-21 09:22:24 -08:00
Ingo Molnar
6ac389346e Revert "kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs"
This reverts commit 77b0bf55bc.

See this commit for details about the revert:

  e769742d35 ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"")

 Conflicts:
	arch/x86/Makefile

Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Juergen Gross <jgross@suse.com>
Cc: Richard Biener <rguenther@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-12-19 12:00:28 +01:00
Thierry Reding
3a6ab5c7dc scripts/spdxcheck.py: always open files in binary mode
The spdxcheck script currently falls over when confronted with a binary
file (such as Documentation/logo.gif).  To avoid that, always open files
in binary mode and decode line-by-line, ignoring encoding errors.

One tricky case is when piping data into the script and reading it from
standard input.  By default, standard input will be opened in text mode,
so we need to reopen it in binary mode.

The breakage only happens with python3 and results in a
UnicodeDecodeError (according to Uwe).

Link: http://lkml.kernel.org/r/20181212131210.28024-1-thierry.reding@gmail.com
Fixes: 6f4d29df66 ("scripts/spdxcheck.py: make python3 compliant")
Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Jeremy Cline <jcline@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Joe Perches <joe@perches.com>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-14 15:05:45 -08:00
Qian Cai
f1733a1d3c checkstack.pl: fix for aarch64
There is actually a space after "sp," like this,

    ffff2000080813c8:       a9bb7bfd        stp     x29, x30, [sp, #-80]!

Right now, checkstack.pl isn't able to print anything on aarch64,
because it won't be able to match the stating objdump line of a function
due to this missing space.  Hence, it displays every stack as zero-size.

After this patch, checkpatch.pl is able to match the start of a
function's objdump, and is then able to calculate each function's stack
correctly.

Link: http://lkml.kernel.org/r/20181207195843.38528-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-14 15:05:45 -08:00
Linus Torvalds
1cdc3624a1 Fixes for stackleak
- Remove tracing for inserted stack depth marking function (Anders Roxell)
 - Move gcc-plugin pass location to avoid objtool warnings (Alexander Popov)
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Merge tag 'gcc-plugins-v4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull gcc stackleak plugin fixes from Kees Cook:

 - Remove tracing for inserted stack depth marking function (Anders
   Roxell)

 - Move gcc-plugin pass location to avoid objtool warnings (Alexander
   Popov)

* tag 'gcc-plugins-v4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  stackleak: Register the 'stackleak_cleanup' pass before the '*free_cfg' pass
  stackleak: Mark stackleak_track_stack() as notrace
2018-12-07 13:13:07 -08:00
Alexander Popov
8fb2dfb228 stackleak: Register the 'stackleak_cleanup' pass before the '*free_cfg' pass
Currently the 'stackleak_cleanup' pass deleting a CALL insn is executed
after the 'reload' pass. That allows gcc to do some weird optimization in
function prologues and epilogues, which are generated later [1].

Let's avoid that by registering the 'stackleak_cleanup' pass before
the '*free_cfg' pass. It's the moment when the stack frame size is
already final, function prologues and epilogues are generated, and the
machine-dependent code transformations are not done.

[1] https://www.openwall.com/lists/kernel-hardening/2018/11/23/2

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Alexander Popov <alex.popov@linux.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2018-12-06 09:10:23 -08:00
Linus Torvalds
4b78317679 Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull STIBP fallout fixes from Thomas Gleixner:
 "The performance destruction department finally got it's act together
  and came up with a cure for the STIPB regression:

   - Provide a command line option to control the spectre v2 user space
     mitigations. Default is either seccomp or prctl (if seccomp is
     disabled in Kconfig). prctl allows mitigation opt-in, seccomp
     enables the migitation for sandboxed processes.

   - Rework the code to handle the conditional STIBP/IBPB control and
     remove the now unused ptrace_may_access_sched() optimization
     attempt

   - Disable STIBP automatically when SMT is disabled

   - Optimize the switch_to() logic to avoid MSR writes and invocations
     of __switch_to_xtra().

   - Make the asynchronous speculation TIF updates synchronous to
     prevent stale mitigation state.

  As a general cleanup this also makes retpoline directly depend on
  compiler support and removes the 'minimal retpoline' option which just
  pretended to provide some form of security while providing none"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
  x86/speculation: Provide IBPB always command line options
  x86/speculation: Add seccomp Spectre v2 user space protection mode
  x86/speculation: Enable prctl mode for spectre_v2_user
  x86/speculation: Add prctl() control for indirect branch speculation
  x86/speculation: Prepare arch_smt_update() for PRCTL mode
  x86/speculation: Prevent stale SPEC_CTRL msr content
  x86/speculation: Split out TIF update
  ptrace: Remove unused ptrace_may_access_sched() and MODE_IBRS
  x86/speculation: Prepare for conditional IBPB in switch_mm()
  x86/speculation: Avoid __switch_to_xtra() calls
  x86/process: Consolidate and simplify switch_to_xtra() code
  x86/speculation: Prepare for per task indirect branch speculation control
  x86/speculation: Add command line control for indirect branch speculation
  x86/speculation: Unify conditional spectre v2 print functions
  x86/speculataion: Mark command line parser data __initdata
  x86/speculation: Mark string arrays const correctly
  x86/speculation: Reorder the spec_v2 code
  x86/l1tf: Show actual SMT state
  x86/speculation: Rework SMT state change
  sched/smt: Expose sched_smt_present static key
  ...
2018-12-01 12:35:48 -08:00
Linus Torvalds
38c7b224ce unifdef: use memcpy instead of strncpy
New versions of gcc reasonably warn about the odd pattern of

	strncpy(p, q, strlen(q));

which really doesn't make sense: the strncpy() ends up being just a slow
and odd way to write memcpy() in this case.

There was a comment about _why_ the code used strncpy - to avoid the
terminating NUL byte, but memcpy does the same and avoids the warning.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30 14:45:01 -08:00
Zhenzhong Duan
4cd24de3a0 x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support
Since retpoline capable compilers are widely available, make
CONFIG_RETPOLINE hard depend on the compiler capability.

Break the build when CONFIG_RETPOLINE is enabled and the compiler does not
support it. Emit an error message in that case:

 "arch/x86/Makefile:226: *** You are building kernel with non-retpoline
  compiler, please update your compiler..  Stop."

[dwmw: Fail the build with non-retpoline compiler]

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Borislav Petkov <bp@suse.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: <srinivas.eeda@oracle.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/cca0cb20-f9e2-4094-840b-fb0f8810cd34@default
2018-11-28 11:57:03 +01:00
Uwe Kleine-König
6f4d29df66 scripts/spdxcheck.py: make python3 compliant
Without this change the following happens when using Python3 (3.6.6):

	$ echo "GPL-2.0" | python3 scripts/spdxcheck.py -
	FAIL: 'str' object has no attribute 'decode'
	Traceback (most recent call last):
	  File "scripts/spdxcheck.py", line 253, in <module>
	    parser.parse_lines(sys.stdin, args.maxlines, '-')
	  File "scripts/spdxcheck.py", line 171, in parse_lines
	    line = line.decode(locale.getpreferredencoding(False), errors='ignore')
	AttributeError: 'str' object has no attribute 'decode'

So as the line is already a string, there is no need to decode it and
the line can be dropped.

/usr/bin/python on Arch is Python 3.  So this would indeed be worth
going into 4.19.

Link: http://lkml.kernel.org/r/20181023070802.22558-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Joe Perches <joe@perches.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-18 10:15:10 -08:00
Randy Dunlap
f5f67cc0e0 scripts/faddr2line: fix location of start_kernel in comment
Fix a source file reference location to the correct path name.

Link: http://lkml.kernel.org/r/1d50bd3d-178e-dcd8-779f-9711887440eb@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-18 10:15:09 -08:00
Rob Herring
d5615e472d builddeb: Fix inclusion of dtbs in debian package
Commit 37c8a5fafa ("kbuild: consolidate Devicetree dtb build rules")
moved the location of 'dtbs_install' target which caused dtbs to not be
installed when building debian package with 'bindeb-pkg' target. Update
the builddeb script to use the same logic that determines if there's a
'dtbs_install' target which is presence of the arch dts directory. Also,
use CONFIG_OF_EARLY_FLATTREE instead of CONFIG_OF as that's a better
indication of whether we are building dtbs.

This commit will also have the side effect of installing dtbs on any
arch that has dts files. Previously, it was dependent on whether the
arch defined 'dtbs_install'.

Fixes: 37c8a5fafa ("kbuild: consolidate Devicetree dtb build rules")
Reported-by: Nuno Gonçalves <nunojpg@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-11-11 23:04:53 +09:00
Guenter Roeck
8ef14c2c41 Revert "scripts/setlocalversion: git: Make -dirty check more robust"
This reverts commit 6147b1cf19.

The reverted patch results in attempted write access to the source
repository, even if that repository is mounted read-only.

Output from "strace git status -uno --porcelain":

getcwd("/tmp/linux-test", 129)          = 16
open("/tmp/linux-test/.git/index.lock", O_RDWR|O_CREAT|O_EXCL|O_CLOEXEC, 0666) =
	-1 EROFS (Read-only file system)

While git appears to be able to handle this situation, a monitored
build environment (such as the one used for Chrome OS kernel builds)
may detect it and bail out with an access violation error. On top of
that, the attempted write access suggests that git _will_ write to the
file even if a build output directory is specified. Users may have the
reasonable expectation that the source repository remains untouched in
that situation.

Fixes: 6147b1cf19 ("scripts/setlocalversion: git: Make -dirty check more robust"
Cc: Genki Sky <sky@genki.is>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-11-11 23:04:52 +09:00
Masahiro Yamada
bbcde0a724 kbuild: deb-pkg: fix too low build version number
Since commit b41d920acf ("kbuild: deb-pkg: split generating packaging
and build"), the build version of the kernel contained in a deb package
is too low by 1.

Prior to the bad commit, the kernel was built first, then the number
in .version file was read out, and written into the debian control file.

Now, the debian control file is created before the kernel is actually
compiled, which is causing the version number mismatch.

Let the mkdebian script pass KBUILD_BUILD_VERSION=${revision} to require
the build system to use the specified version number.

Fixes: b41d920acf ("kbuild: deb-pkg: split generating packaging and build")
Reported-by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Doug Smythies <dsmythies@telus.net>
2018-11-11 23:04:52 +09:00
Masahiro Yamada
6bbe4385d0 kconfig: merge_config: avoid false positive matches from comment lines
The current SED_CONFIG_EXP could match to comment lines in config
fragment files, especially when CONFIG_PREFIX_ is empty. For example,
Buildroot uses empty prefixing; starting symbols with BR2_ is just
convention.

Make the sed expression more robust against false positives from
comment lines. The new sed expression matches to only valid patterns.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Petr Vorel <petr.vorel@gmail.com>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
2018-11-11 23:04:51 +09:00
Masahiro Yamada
02826a6ba3 kbuild: deb-pkg: fix bindeb-pkg breakage when O= is used
Ard Biesheuvel reports bindeb-pkg with O= option is broken in the
following way:

  ...
    LD [M]  sound/soc/rockchip/snd-soc-rk3399-gru-sound.ko
    LD [M]  sound/soc/rockchip/snd-soc-rockchip-pcm.ko
    LD [M]  sound/soc/rockchip/snd-soc-rockchip-rt5645.ko
    LD [M]  sound/soc/rockchip/snd-soc-rockchip-spdif.ko
    LD [M]  sound/soc/sh/rcar/snd-soc-rcar.ko
   fakeroot -u debian/rules binary
  make KERNELRELEASE=4.19.0-12677-g19beffaf7a99-dirty ARCH=arm64 KBUILD_SRC= intdeb-pkg
  /bin/bash /home/ard/linux/scripts/package/builddeb
  Makefile:600: include/config/auto.conf: No such file or directory
  ***
  *** Configuration file ".config" not found!
  ***
  *** Please run some configurator (e.g. "make oldconfig" or
  *** "make menuconfig" or "make xconfig").
  ***
  make[12]: *** [syncconfig] Error 1
  make[11]: *** [syncconfig] Error 2
  make[10]: *** [include/config/auto.conf] Error 2
  make[9]: *** [__sub-make] Error 2
  ...

Prior to commit 80463f1b7b ("kbuild: add --include-dir flag only
for out-of-tree build"), both srctree and objtree were added to
--include-dir redundantly, and the wrong code '$MAKE image_name'
was working by relying on that. Now, the potential issue that had
previously been hidden just showed up.

'$MAKE image_name' recurses to the generated $(objtree)/Makefile and
ends up with running in srctree, which is incorrect. It should be
invoked with '-f $srctree/Makefile' (or KBUILD_SRC=) to be executed
in objtree.

Fixes: 80463f1b7b ("kbuild: add --include-dir flag only for out-of-tree build")
Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2018-11-06 01:29:00 +09:00
Masahiro Yamada
21b42eb468 kbuild: rpm-pkg: fix binrpm-pkg breakage when O= is used
Zhenzhong Duan reported that running 'make O=/build/kernel binrpm-pkg'
failed with the following errors:

  Running 'make O=/build/kernel binrpm-pkg' failed with below two errors.

  Makefile:600: include/config/auto.conf: No such file or directory

  + cp make -C /mnt/root/kernel O=/build/kernel image_name make -f
  /mnt/root/kernel/Makefile ...
  cp: invalid option -- 'C'
  Try 'cp --help' for more information.

Prior to commit 80463f1b7b ("kbuild: add --include-dir flag only
for out-of-tree build"), both srctree and objtree were added to
--include-dir redundantly, and the wrong code 'make image_name'
was working by relying on that. Now, the potential issue that had
previously been hidden just showed up.

'make image_name' recurses to the generated $(objtree)/Makefile and
ends up with running in srctree, which is incorrect. It should be
invoked with '-f $srctree/Makefile' (or KBUILD_SRC=) to be executed
in objtree.

Fixes: 80463f1b7b ("kbuild: add --include-dir flag only for out-of-tree build")
Reported-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-11-06 01:28:48 +09:00
Linus Torvalds
9a12efc5e0 Kbuild updates for v4.20 (2nd)
- clean-up leftovers in Kconfig files
 
 - remove stale oldnoconfig and silentoldconfig targets
 
 - remove unneeded cc-fullversion and cc-name variables
 
 - improve merge_config script to allow overriding option prefix
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Merge tag 'kbuild-v4.20-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - clean-up leftovers in Kconfig files

 - remove stale oldnoconfig and silentoldconfig targets

 - remove unneeded cc-fullversion and cc-name variables

 - improve merge_config script to allow overriding option prefix

* tag 'kbuild-v4.20-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: remove cc-name variable
  kbuild: replace cc-name test with CONFIG_CC_IS_CLANG
  merge_config.sh: Allow to define config prefix
  kbuild: remove unused cc-fullversion variable
  kconfig: remove silentoldconfig target
  kconfig: remove oldnoconfig target
  powerpc: PCI_MSI needs PCI
  powerpc: remove CONFIG_MCA leftovers
  powerpc: remove CONFIG_PCI_QSPAN
  scsi: aha152x: rename the PCMCIA define
2018-11-03 10:47:33 -07:00
Masahiro Yamada
9951674207 kbuild: remove cc-name variable
There is one more user of $(cc-name) in the top Makefile. It is supposed
to detect Clang before invoking Kconfig, so it should still be there
in the $(shell ...) form. All the other users of $(cc-name) have been
replaced with $(CONFIG_CC_IS_CLANG). Hence, scripts/Kbuild.include does
not need to define cc-name any more.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-11-02 22:49:01 +09:00
Masahiro Yamada
076f421da5 kbuild: replace cc-name test with CONFIG_CC_IS_CLANG
Evaluating cc-name invokes the compiler every time even when you are
not compiling anything, like 'make help'. This is not efficient.

The compiler type has been already detected in the Kconfig stage.
Use CONFIG_CC_IS_CLANG, instead.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Paul Burton <paul.burton@mips.com> (MIPS)
Acked-by: Joel Stanley <joel@jms.id.au>
2018-11-02 22:49:00 +09:00
Linus Torvalds
e468f5c06b The Compiler Attributes series
This is an effort to disentangle the include/linux/compiler*.h headers
 and bring them up to date.
 
 The main idea behind the series is to use feature checking macros
 (i.e. __has_attribute) instead of compiler version checks (e.g. GCC_VERSION),
 which are compiler-agnostic (so they can be shared, reducing the size
 of compiler-specific headers) and version-agnostic.
 
 Other related improvements have been performed in the headers as well,
 which on top of the use of __has_attribute it has amounted to a significant
 simplification of these headers (e.g. GCC_VERSION is now only guarding
 a few non-attribute macros).
 
 This series should also help the efforts to support compiling the kernel
 with clang and icc. A fair amount of documentation and comments have also
 been added, clarified or removed; and the headers are now more readable,
 which should help kernel developers in general.
 
 The series was triggered due to the move to gcc >= 4.6. In turn, this series
 has also triggered Sparse to gain the ability to recognize __has_attribute
 on its own.
 
 Finally, the __nonstring variable attribute series has been also applied
 on top; plus two related patches from Nick Desaulniers for unreachable()
 that came a bit afterwards.
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Merge tag 'compiler-attributes-for-linus-4.20-rc1' of https://github.com/ojeda/linux

Pull compiler attribute updates from Miguel Ojeda:
 "This is an effort to disentangle the include/linux/compiler*.h headers
  and bring them up to date.

  The main idea behind the series is to use feature checking macros
  (i.e. __has_attribute) instead of compiler version checks (e.g.
  GCC_VERSION), which are compiler-agnostic (so they can be shared,
  reducing the size of compiler-specific headers) and version-agnostic.

  Other related improvements have been performed in the headers as well,
  which on top of the use of __has_attribute it has amounted to a
  significant simplification of these headers (e.g. GCC_VERSION is now
  only guarding a few non-attribute macros).

  This series should also help the efforts to support compiling the
  kernel with clang and icc. A fair amount of documentation and comments
  have also been added, clarified or removed; and the headers are now
  more readable, which should help kernel developers in general.

  The series was triggered due to the move to gcc >= 4.6. In turn, this
  series has also triggered Sparse to gain the ability to recognize
  __has_attribute on its own.

  Finally, the __nonstring variable attribute series has been also
  applied on top; plus two related patches from Nick Desaulniers for
  unreachable() that came a bit afterwards"

* tag 'compiler-attributes-for-linus-4.20-rc1' of https://github.com/ojeda/linux:
  compiler-gcc: remove comment about gcc 4.5 from unreachable()
  compiler.h: update definition of unreachable()
  Compiler Attributes: ext4: remove local __nonstring definition
  Compiler Attributes: auxdisplay: panel: use __nonstring
  Compiler Attributes: enable -Wstringop-truncation on W=1 (gcc >= 8)
  Compiler Attributes: add support for __nonstring (gcc >= 8)
  Compiler Attributes: add MAINTAINERS entry
  Compiler Attributes: add Doc/process/programming-language.rst
  Compiler Attributes: remove uses of __attribute__ from compiler.h
  Compiler Attributes: KENTRY used twice the "used" attribute
  Compiler Attributes: use feature checks instead of version checks
  Compiler Attributes: add missing SPDX ID in compiler_types.h
  Compiler Attributes: remove unneeded sparse (__CHECKER__) tests
  Compiler Attributes: homogenize __must_be_array
  Compiler Attributes: remove unneeded tests
  Compiler Attributes: always use the extra-underscores syntax
  Compiler Attributes: remove unused attributes
2018-11-01 18:34:46 -07:00
Linus Torvalds
2d6bb6adb7 New gcc plugin: stackleak
- Introduces the stackleak gcc plugin ported from grsecurity by Alexander
   Popov, with x86 and arm64 support.
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Merge tag 'stackleak-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull stackleak gcc plugin from Kees Cook:
 "Please pull this new GCC plugin, stackleak, for v4.20-rc1. This plugin
  was ported from grsecurity by Alexander Popov. It provides efficient
  stack content poisoning at syscall exit. This creates a defense
  against at least two classes of flaws:

   - Uninitialized stack usage. (We continue to work on improving the
     compiler to do this in other ways: e.g. unconditional zero init was
     proposed to GCC and Clang, and more plugin work has started too).

   - Stack content exposure. By greatly reducing the lifetime of valid
     stack contents, exposures via either direct read bugs or unknown
     cache side-channels become much more difficult to exploit. This
     complements the existing buddy and heap poisoning options, but
     provides the coverage for stacks.

  The x86 hooks are included in this series (which have been reviewed by
  Ingo, Dave Hansen, and Thomas Gleixner). The arm64 hooks have already
  been merged through the arm64 tree (written by Laura Abbott and
  reviewed by Mark Rutland and Will Deacon).

  With VLAs having been removed this release, there is no need for
  alloca() protection, so it has been removed from the plugin"

* tag 'stackleak-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  arm64: Drop unneeded stackleak_check_alloca()
  stackleak: Allow runtime disabling of kernel stack erasing
  doc: self-protection: Add information about STACKLEAK feature
  fs/proc: Show STACKLEAK metrics in the /proc file system
  lkdtm: Add a test for STACKLEAK
  gcc-plugins: Add STACKLEAK plugin for tracking the kernel stack
  x86/entry: Add STACKLEAK erasing the kernel stack at the end of syscalls
2018-11-01 11:46:27 -07:00
Petr Vorel
2cd3faf87d merge_config.sh: Allow to define config prefix
with CONFIG_ environment variable.

merge_config.sh uses CONFIG_ which is used in kernel and other projects.
There are some projects which use kconfig with different prefixes (e.g.
buildroot: BR2_ prefix). CONFIG_ variable is already used for this
purpose in kconfig binary (scripts/kconfig/lkc.h), let's use the same
rule for in merge_config.sh.

Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Petr Vorel <petr.vorel@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-11-02 00:15:26 +09:00
Masahiro Yamada
3f80babd9c kbuild: remove unused cc-fullversion variable
The last user of cc-fullversion was removed by commit f2910f0e68
("powerpc: remove old GCC version checks").

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-11-02 00:15:26 +09:00
Masahiro Yamada
0085b4191f kconfig: remove silentoldconfig target
As commit 911a91c39c ("kconfig: rename silentoldconfig to
syncconfig") announced, it is time for the removal.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2018-11-02 00:15:25 +09:00
Masahiro Yamada
04c459d204 kconfig: remove oldnoconfig target
As commit 312ee68752 ("kconfig: announce removal of oldnoconfig if
used") announced, it is time for the removal.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-11-02 00:15:25 +09:00
Christophe Leroy
22ebb72b32 checkpatch: remove GCC_BINARY_CONSTANT warning
This warning was there to avoid the use of 0bxxx values as they are not
supported by gcc prior to v4.3

Since cafa0010cd ("Raise the minimum required gcc version to 4.6"),
it's not an issue anymore and using such values can increase readability
of code.

Joe said:

: Seems sensible as the other compilers also support binary literals from
: relatively old versions.
: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3472.pdf
: https://software.intel.com/en-us/articles/c14-features-supported-by-intel-c-compiler

Link: http://lkml.kernel.org/r/392eeae782302ee8812a3c932a602035deed1609.1535351453.git.christophe.leroy@c-s.fr
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-31 08:54:13 -07:00
Linus Torvalds
746bb4ed6d Globally warn on VLA use
- Remove unused fallback for BUILD_BUG_ON (which technically contains a VLA)
 - Lift -Wvla to the top-level Makefile
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Merge tag 'vla-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull VLA removal from Kees Cook:
 "Globally warn on VLA use.

  This turns on "-Wvla" globally now that the last few trees with their
  VLA removals have landed (crypto, block, net, and powerpc).

  Arnd mentioned that there may be a couple more VLAs hiding in
  hard-to-find randconfigs, but nothing big has shaken out in the last
  month or so in linux-next.

  We should be basically VLA-free now! Wheee. :)

  Summary:

   - Remove unused fallback for BUILD_BUG_ON (which technically contains
     a VLA)

   - Lift -Wvla to the top-level Makefile"

* tag 'vla-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  Makefile: Globally enable VLA warning
  compiler.h: give up __compiletime_assert_fallback()
2018-10-28 13:26:45 -07:00
Linus Torvalds
ac747c0715 Kbuild updates for v4.20
- optimize kallsyms slightly
 
 - remove check for old CFLAGS usage
 
 - add some compiler flags unconditionally instead of evaluating
   $(call cc-option,...)
 
 - fix variable shadowing in host tools
 
 - refactor scripts/mkmakefile
 
 - refactor various makefiles
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Merge tag 'kbuild-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - optimize kallsyms slightly

 - remove check for old CFLAGS usage

 - add some compiler flags unconditionally instead of evaluating
   $(call cc-option,...)

 - fix variable shadowing in host tools

 - refactor scripts/mkmakefile

 - refactor various makefiles

* tag 'kbuild-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  modpost: Create macro to avoid variable shadowing
  ASN.1: Remove unnecessary shadowed local variable
  kbuild: use 'else ifeq' for checksrc to improve readability
  kbuild: remove unneeded link_multi_deps
  kbuild: add -Wno-unused-but-set-variable flag unconditionally
  kbuild: add -Wdeclaration-after-statement flag unconditionally
  kbuild: add -Wno-pointer-sign flag unconditionally
  modpost: remove leftover symbol prefix handling for module device table
  kbuild: simplify command line creation in scripts/mkmakefile
  kbuild: do not pass $(objtree) to scripts/mkmakefile
  kbuild: remove user ID check in scripts/mkmakefile
  kbuild: remove VERSION and PATCHLEVEL from $(objtree)/Makefile
  kbuild: add --include-dir flag only for out-of-tree build
  kbuild: remove dead code in cmd_files calculation in top Makefile
  kbuild: hide most of targets when running config or mixed targets
  kbuild: remove old check for CFLAGS use
  kbuild: prefix Makefile.dtbinst path with $(srctree) unconditionally
  kallsyms: remove left-over Blackfin code
  kallsyms: reduce size a little on 64-bit
2018-10-28 13:22:35 -07:00
Leonardo Bras
c2b1a9226f modpost: Create macro to avoid variable shadowing
Create DEF_FIELD_ADDR_VAR as a more generic version of the DEF_FIELD_ADD
macro, allowing usage of a variable name other than the struct element name.
Also, sets DEF_FIELD_ADDR as a specific usage of DEF_FILD_ADDR_VAR in which
the var name is the same as the struct element name.
Then, makes use of DEF_FIELD_ADDR_VAR to create a variable of another name,
in order to avoid variable shadowing.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-10-29 00:41:41 +09:00
Leonardo Bras
9e1e819433 ASN.1: Remove unnecessary shadowed local variable
Remove an unnecessary shadowed local variable (start).
It was used only once, with the same value it was started before
the if block.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-10-29 00:19:41 +09:00
Linus Torvalds
345671ea0f Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:

 - a few misc things

 - ocfs2 updates

 - most of MM

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (132 commits)
  hugetlbfs: dirty pages as they are added to pagecache
  mm: export add_swap_extent()
  mm: split SWP_FILE into SWP_ACTIVATED and SWP_FS
  tools/testing/selftests/vm/map_fixed_noreplace.c: add test for MAP_FIXED_NOREPLACE
  mm: thp: relocate flush_cache_range() in migrate_misplaced_transhuge_page()
  mm: thp: fix mmu_notifier in migrate_misplaced_transhuge_page()
  mm: thp: fix MADV_DONTNEED vs migrate_misplaced_transhuge_page race condition
  mm/kasan/quarantine.c: make quarantine_lock a raw_spinlock_t
  mm/gup: cache dev_pagemap while pinning pages
  Revert "x86/e820: put !E820_TYPE_RAM regions into memblock.reserved"
  mm: return zero_resv_unavail optimization
  mm: zero remaining unavailable struct pages
  tools/testing/selftests/vm/gup_benchmark.c: add MAP_HUGETLB option
  tools/testing/selftests/vm/gup_benchmark.c: add MAP_SHARED option
  tools/testing/selftests/vm/gup_benchmark.c: allow user specified file
  tools/testing/selftests/vm/gup_benchmark.c: fix 'write' flag usage
  mm/gup_benchmark.c: add additional pinning methods
  mm/gup_benchmark.c: time put_page()
  mm: don't raise MEMCG_OOM event due to failed high-order allocation
  mm/page-writeback.c: fix range_cyclic writeback vs writepages deadlock
  ...
2018-10-26 19:33:41 -07:00
Kirill Tkhai
1f6904f729 scripts/tags.sh: add DECLARE_HASHTABLE()
In addition to DEFINE_HASHTABLE() add DECLARE_ variant.

Link: http://lkml.kernel.org/r/153683203215.13678.11468076350083405643.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Constantine Shulyupin <const@MakeLinux.com>
Cc: Arend van Spriel <arend.vanspriel@broadcom.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Joey Pabalinas <joeypabalinas@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-26 16:25:18 -07:00
Linus Torvalds
b27186abb3 Devicetree updates for 4.20:
- Sync dtc with upstream version v1.4.7-14-gc86da84d30e4
 
 - Work to get rid of direct accesses to struct device_node name and
   type pointers in preparation for removing them. New helpers for
   parsing DT cpu nodes and conversions to use the helpers. printk
   conversions to %pOFn for printing DT node names. Most went thru
   subystem trees, so this is the remainder.
 
 - Fixes to DT child node lookups to actually be restricted to child
   nodes instead of treewide.
 
 - Refactoring of dtb targets out of arch code. This makes the support
   more uniform and enables building all dtbs on c6x, microblaze, and
   powerpc.
 
 - Various DT binding updates for Renesas r8a7744 SoC
 
 - Vendor prefixes for Facebook, OLPC
 
 - Restructuring of some ARM binding docs moving some peripheral bindings
   out of board/SoC binding files
 
 - New "secure-chosen" binding for secure world settings on ARM
 
 - Dual licensing of 2 DT IRQ binding headers
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Merge tag 'devicetree-for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull Devicetree updates from Rob Herring:
 "A bit bigger than normal as I've been busy this cycle.

  There's a few things with dependencies and a few things subsystem
  maintainers didn't pick up, so I'm taking them thru my tree.

  The fixes from Johan didn't get into linux-next, but they've been
  waiting for some time now and they are what's left of what subsystem
  maintainers didn't pick up.

  Summary:

   - Sync dtc with upstream version v1.4.7-14-gc86da84d30e4

   - Work to get rid of direct accesses to struct device_node name and
     type pointers in preparation for removing them. New helpers for
     parsing DT cpu nodes and conversions to use the helpers. printk
     conversions to %pOFn for printing DT node names. Most went thru
     subystem trees, so this is the remainder.

   - Fixes to DT child node lookups to actually be restricted to child
     nodes instead of treewide.

   - Refactoring of dtb targets out of arch code. This makes the support
     more uniform and enables building all dtbs on c6x, microblaze, and
     powerpc.

   - Various DT binding updates for Renesas r8a7744 SoC

   - Vendor prefixes for Facebook, OLPC

   - Restructuring of some ARM binding docs moving some peripheral
     bindings out of board/SoC binding files

   - New "secure-chosen" binding for secure world settings on ARM

   - Dual licensing of 2 DT IRQ binding headers"

* tag 'devicetree-for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (78 commits)
  ARM: dt: relicense two DT binding IRQ headers
  power: supply: twl4030-charger: fix OF sibling-node lookup
  NFC: nfcmrvl_uart: fix OF child-node lookup
  net: stmmac: dwmac-sun8i: fix OF child-node lookup
  net: bcmgenet: fix OF child-node lookup
  drm/msm: fix OF child-node lookup
  drm/mediatek: fix OF sibling-node lookup
  of: Add missing exports of node name compare functions
  dt-bindings: Add OLPC vendor prefix
  dt-bindings: misc: bk4: Add device tree binding for Liebherr's BK4 SPI bus
  dt-bindings: thermal: samsung: Add SPDX license identifier
  dt-bindings: clock: samsung: Add SPDX license identifiers
  dt-bindings: timer: ostm: Add R7S9210 support
  dt-bindings: phy: rcar-gen2: Add r8a7744 support
  dt-bindings: can: rcar_can: Add r8a7744 support
  dt-bindings: timer: renesas, cmt: Document r8a7744 CMT support
  dt-bindings: watchdog: renesas-wdt: Document r8a7744 support
  dt-bindings: thermal: rcar: Add device tree support for r8a7744
  Documentation: dt: Add binding for /secure-chosen/stdout-path
  dt-bindings: arm: zte: Move sysctrl bindings to their own doc
  ...
2018-10-26 12:09:58 -07:00
Linus Torvalds
01aa9d518e This is a fairly typical cycle for documentation. There's some welcome
readability improvements for the formatted output, some LICENSES updates
 including the addition of the ISC license, the removal of the unloved and
 unmaintained 00-INDEX files, the deprecated APIs document from Kees, more
 MM docs from Mike Rapoport, and the usual pile of typo fixes and
 corrections.
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Merge tag 'docs-4.20' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "This is a fairly typical cycle for documentation. There's some welcome
  readability improvements for the formatted output, some LICENSES
  updates including the addition of the ISC license, the removal of the
  unloved and unmaintained 00-INDEX files, the deprecated APIs document
  from Kees, more MM docs from Mike Rapoport, and the usual pile of typo
  fixes and corrections"

* tag 'docs-4.20' of git://git.lwn.net/linux: (41 commits)
  docs: Fix typos in histogram.rst
  docs: Introduce deprecated APIs list
  kernel-doc: fix declaration type determination
  doc: fix a typo in adding-syscalls.rst
  docs/admin-guide: memory-hotplug: remove table of contents
  doc: printk-formats: Remove bogus kobject references for device nodes
  Documentation: preempt-locking: Use better example
  dm flakey: Document "error_writes" feature
  docs/completion.txt: Fix a couple of punctuation nits
  LICENSES: Add ISC license text
  LICENSES: Add note to CDDL-1.0 license that it should not be used
  docs/core-api: memory-hotplug: add some details about locking internals
  docs/core-api: rename memory-hotplug-notifier to memory-hotplug
  docs: improve readability for people with poorer eyesight
  yama: clarify ptrace_scope=2 in Yama documentation
  docs/vm: split memory hotplug notifier description to Documentation/core-api
  docs: move memory hotplug description into admin-guide/mm
  doc: Fix acronym "FEKEK" in ecryptfs
  docs: fix some broken documentation references
  iommu: Fix passthrough option documentation
  ...
2018-10-24 18:01:11 +01:00
Linus Torvalds
44786880df Merge branch 'parisc-4.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc updates from Helge Deller:
 "Lots of small fixes and enhancements, most noteably:

   - Many TLB and cache flush optimizations (Dave)

   - Fixed HPMC/crash handler on 64-bit kernel (Dave and myself)

   - Added alternative infrastructre. The kernel now live-patches itself
     for various situations, e.g. replace SMP code when running on one
     CPU only or drop cache flushes when system has no cache installed.

   - vmlinuz now contains a full copy of the compressed vmlinux file.
     This simplifies debugging the currently booted kernel.

   - Unused driver removal (Christoph)

   - Reduced warnings of Dino PCI bridge when running in qemu

   - Removed gcc version check (Masahiro)"

* 'parisc-4.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: (23 commits)
  parisc: Retrieve and display the PDC PAT capabilities
  parisc: Optimze cache flush algorithms
  parisc: Remove pte_inserted define
  parisc: Add PDC PAT cell_info() and pd_get_pdc_revisions() functions
  parisc: Drop two instructions from pte lookup code
  parisc: Use zdep for shlw macro on PA1.1 and PA2.0
  parisc: Add alternative coding infrastructure
  parisc: Include compressed vmlinux file in vmlinuz boot kernel
  extract-vmlinux: Check for uncompressed image as fallback
  parisc: Fix address in HPMC IVA
  parisc: Fix exported address of os_hpmc handler
  parisc: Fix map_pages() to not overwrite existing pte entries
  parisc: Purge TLB entries after updating page table entry and set page accessed flag in TLB handler
  parisc: Release spinlocks using ordered store
  parisc: Ratelimit dino stuck interrupt warnings
  parisc: dino: Utilize DINO_MASK_IRQ() macro
  parisc: Clean up crash header output
  parisc: Add SYSTEM_INFO and REGISTER TOC PAT functions
  parisc: Remove PTE load and fault check from L2_ptep macro
  parisc: Reorder TLB flush timing calculation
  ...
2018-10-23 20:02:03 +01:00
Linus Torvalds
0200fbdd43 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking and misc x86 updates from Ingo Molnar:
 "Lots of changes in this cycle - in part because locking/core attracted
  a number of related x86 low level work which was easier to handle in a
  single tree:

   - Linux Kernel Memory Consistency Model updates (Alan Stern, Paul E.
     McKenney, Andrea Parri)

   - lockdep scalability improvements and micro-optimizations (Waiman
     Long)

   - rwsem improvements (Waiman Long)

   - spinlock micro-optimization (Matthew Wilcox)

   - qspinlocks: Provide a liveness guarantee (more fairness) on x86.
     (Peter Zijlstra)

   - Add support for relative references in jump tables on arm64, x86
     and s390 to optimize jump labels (Ard Biesheuvel, Heiko Carstens)

   - Be a lot less permissive on weird (kernel address) uaccess faults
     on x86: BUG() when uaccess helpers fault on kernel addresses (Jann
     Horn)

   - macrofy x86 asm statements to un-confuse the GCC inliner. (Nadav
     Amit)

   - ... and a handful of other smaller changes as well"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
  locking/lockdep: Make global debug_locks* variables read-mostly
  locking/lockdep: Fix debug_locks off performance problem
  locking/pvqspinlock: Extend node size when pvqspinlock is configured
  locking/qspinlock_stat: Count instances of nested lock slowpaths
  locking/qspinlock, x86: Provide liveness guarantee
  x86/asm: 'Simplify' GEN_*_RMWcc() macros
  locking/qspinlock: Rework some comments
  locking/qspinlock: Re-order code
  locking/lockdep: Remove duplicated 'lock_class_ops' percpu array
  x86/defconfig: Enable CONFIG_USB_XHCI_HCD=y
  futex: Replace spin_is_locked() with lockdep
  locking/lockdep: Make class->ops a percpu counter and move it under CONFIG_DEBUG_LOCKDEP=y
  x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs
  x86/cpufeature: Macrofy inline assembly code to work around GCC inlining bugs
  x86/extable: Macrofy inline assembly code to work around GCC inlining bugs
  x86/paravirt: Work around GCC inlining bugs when compiling paravirt ops
  x86/bug: Macrofy the BUG table section handling, to work around GCC inlining bugs
  x86/alternatives: Macrofy lock prefixes to work around GCC inlining bugs
  x86/refcount: Work around GCC inlining bug
  x86/objtool: Use asm macros to work around GCC inlining bugs
  ...
2018-10-23 13:08:53 +01:00
Masahiro Yamada
7d0ea25242 kbuild: use 'else ifeq' for checksrc to improve readability
'ifeq ... else ifeq ... endif' notation is supported by GNU Make 3.81
or later, which is the requirement for building the kernel since
commit 37d69ee308 ("docs: bump minimal GNU Make version to 3.81").

Use it to improve the readability.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-10-19 09:48:47 +09:00
Masahiro Yamada
69ea912fda kbuild: remove unneeded link_multi_deps
Since commit c8589d1e9e ("kbuild: handle multi-objs dependency
appropriately"), $^ really represents all the prerequisite of the
composite object being built.

Hence, $(filter %.o,$^) contains all the objects to link together,
which is much simpler than link_multi_deps calculation.

Please note $(filter-out FORCE,$^) does not work here. When a single
object module is turned into a multi object module, $^ will contain
header files that were previously included for building the single
object, and recorded in the .*.cmd file. To filter out such headers,
$(filter %.o,$^) should be used here.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-10-19 09:47:46 +09:00
Masahiro Yamada
153e04b373 modpost: remove leftover symbol prefix handling for module device table
Blackfin and metag were the only architectures that prefix symbols with
an underscore. They were removed by commit 4ba66a9760 ("arch: remove
blackfin port"), commit bb6fb6dfcc ("metag: Remove arch/metag/"),
respectively.

It is no longer necessary to handle <prefix> part of module device
table symbols.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-10-19 09:47:44 +09:00
Randy Dunlap
cf419d542f kernel-doc: fix declaration type determination
Make declaration type determination more robust.

When scripts/kernel-doc is deciding if some kernel-doc notation
contains an enum, a struct, a union, a typedef, or a function,
it does a pattern match on the beginning of the string, looking
for a match with one of "struct", "union", "enum", or "typedef",
and otherwise defaults to a function declaration type.
However, if a function or a function-like macro has a name that
begins with "struct" (e.g., struct_size()), then kernel-doc
incorrectly decides that this is a struct declaration.

Fix this by looking for the declaration type keywords having an
ending word boundary (\b), so that "struct_size" will not match
a struct declaration.

I compared lots of html before/after output from core-api, driver-api,
and networking.  There were no differences in any of the files that
I checked.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-10-18 12:20:35 -06:00
Helge Deller
db139d71c4 extract-vmlinux: Check for uncompressed image as fallback
As on x86-64 and other architectures, the boot kernel on parisc (vmlinuz
and bzImage) contains a full compressed copy of the final kernel
executable (vmlinux.bin.gz), which one should be able to extract with
the extract-vmlinux script.

But on parisc extracting the kernel with extract-vmlinux fails.
Currently the script first checks if the given file is an ELF file
(which is true on parisc) and if so returns it.  Thus on parisc we
unexpectedly get back the vmlinuz boot file instead of the uncompressed
vmlinux image.

This patch fixes this issue by reverting the logic. It now first tries
to find a compression signature in the given file and if that fails it
checks the file itself as fallback.

Signed-off-by: Helge Deller <deller@gmx.de>
2018-10-17 08:18:01 +02:00
Greg Kroah-Hartman
e5337178f7 Kbuild fixes for v4.19 (2nd)
- Fix warnings from recordmcount.pl when building with Clang
 
  - Allow Clang to use GNU toolchains correctly
 
  - Disable CONFIG_SAMPLES for UML to avoid build error
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Merge tag 'kbuild-fixes-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Masahiro writes:
  "Kbuild fixes for v4.19 (2nd)
   - Fix warnings from recordmcount.pl when building with Clang
   - Allow Clang to use GNU toolchains correctly
   - Disable CONFIG_SAMPLES for UML to avoid build error"

* tag 'kbuild-fixes-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  samples: disable CONFIG_SAMPLES for UML
  kbuild: allow to use GCC toolchain not in Clang search path
  ftrace: Build with CPPFLAGS to get -Qunused-arguments
2018-10-11 19:23:07 +02:00
Kees Cook
0bb95f80a3 Makefile: Globally enable VLA warning
Now that Variable Length Arrays (VLAs) have been entirely removed[1]
from the kernel, enable the VLA warning globally. The only exceptions
to this are the KASan an UBSan tests which are explicitly checking that
VLAs trigger their respective tests.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Airlie <airlied@linux.ie>
Cc: linux-kbuild@vger.kernel.org
Cc: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2018-10-11 08:17:50 -07:00
Rob Herring
4355151de4 Merge branch 'all-dtbs' into dt/next 2018-10-04 14:16:15 -05:00
Masahiro Yamada
80d0dda3a4 kbuild: simplify command line creation in scripts/mkmakefile
Assuming we never invoke the generated Makefile from outside of
the $(objtree) directory, $(CURDIR) points to the absolute path
of $(objtree).

BTW, 'lastword' is natively supported by GNU Make 3.81+, which
is the current requirement for building the kernel.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-10-04 22:56:02 +09:00
Masahiro Yamada
4fd61277f6 kbuild: do not pass $(objtree) to scripts/mkmakefile
Since $(objtree) is always '.', it is not useful to pass it to
scripts/mkmakefile.  I assume nobody wants to run this script directly.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-10-04 22:56:02 +09:00
Masahiro Yamada
74bc0c09b2 kbuild: remove user ID check in scripts/mkmakefile
This line was added by commit fd5f0cd6b0 ("kbuild: Do not overwrite
makefile as anohter user").  Its commit description says the intention
was to prevent $(objtree)/Makefile from being owned by root when e.g.
running 'make install'.

However, as commit 19514fc665 ("arm, kbuild: make "make install" not
depend on vmlinux") stated, installation targets must not modify the
source tree in the first place.  If they do, we are already screwed up.
We must fix the root cause.

Installation targets should just copy files verbatim, hence we never
expect $(objtree)/Makefile is touched by root.  The user ID check in
scripts/mkmakefile is unneeded.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-10-04 22:56:02 +09:00
Masahiro Yamada
77ec0c20c7 kbuild: remove VERSION and PATCHLEVEL from $(objtree)/Makefile
Neither VERSION nor PATCHLEVEL is used in any useful way.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-10-04 22:56:01 +09:00
Nadav Amit
77b0bf55bc kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs
Using macros in inline assembly allows us to work around bugs
in GCC's inlining decisions.

Compile macros.S and use it to assemble all C files.
Currently only x86 will use it.

Background:

The inlining pass of GCC doesn't include an assembler, so it's not aware
of basic properties of the generated code, such as its size in bytes,
or that there are such things as discontiuous blocks of code and data
due to the newfangled linker feature called 'sections' ...

Instead GCC uses a lazy and fragile heuristic: it does a linear count of
certain syntactic and whitespace elements in inlined assembly block source
code, such as a count of new-lines and semicolons (!), as a poor substitute
for "code size and complexity".

Unsurprisingly this heuristic falls over and breaks its neck whith certain
common types of kernel code that use inline assembly, such as the frequent
practice of putting useful information into alternative sections.

As a result of this fresh, 20+ years old GCC bug, GCC's inlining decisions
are effectively disabled for inlined functions that make use of such asm()
blocks, because GCC thinks those sections of code are "large" - when in
reality they are often result in just a very low number of machine
instructions.

This absolute lack of inlining provess when GCC comes across such asm()
blocks both increases generated kernel code size and causes performance
overhead, which is particularly noticeable on paravirt kernels, which make
frequent use of these inlining facilities in attempt to stay out of the
way when running on baremetal hardware.

Instead of fixing the compiler we use a workaround: we set an assembly macro
and call it from the inlined assembly block. As a result GCC considers the
inline assembly block as a single instruction. (Which it often isn't but I digress.)

This uglifies and bloats the source code - for example just the refcount
related changes have this impact:

 Makefile                 |    9 +++++++--
 arch/x86/Makefile        |    7 +++++++
 arch/x86/kernel/macros.S |    7 +++++++
 scripts/Kbuild.include   |    4 +++-
 scripts/mod/Makefile     |    2 ++
 5 files changed, 26 insertions(+), 3 deletions(-)

Yay readability and maintainability, it's not like assembly code is hard to read
and maintain ...

We also hope that GCC will eventually get fixed, but we are not holding
our breath for that. Yet we are optimistic, it might still happen, any decade now.

[ mingo: Wrote new changelog describing the background. ]

Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kbuild@vger.kernel.org
Link: http://lkml.kernel.org/r/20181003213100.189959-3-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-04 10:57:09 +02:00