3930 Commits

Author SHA1 Message Date
Ard Biesheuvel
0f66784ae2 scripts/kallsyms: remove last remnants of --page-offset option
The implementation of the --page-offset kallsyms command line option has
been removed, so remove it from the usage string as well.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-12-11 12:46:15 +01:00
Ben Hutchings
79e51b5c2d kconfig/nconf: Fix hang when editing symbol with a long prompt
Currently it is impossible to edit the value of a config symbol with a
prompt longer than (terminal width - 2) characters.  dialog_inputbox()
calculates a negative x-offset for the input window and newwin() fails
as this is invalid.  It also doesn't check for this failure, so it
busy-loops calling wgetch(NULL) which immediately returns -1.

The additions in the offset calculations also don't match the intended
size of the window.

Limit the window size and calculate the offset similarly to
show_scroll_win().

Cc: stable <stable@vger.kernel.org>
Fixes: 692d97c380c6 ("kconfig: new configuration interface (nconfig)")
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
2016-12-11 12:26:42 +01:00
Vaishali Thakkar
d1e774f49f Coccinelle: misc: Add support for devm variant in all modes
Add missing support for the devm_request_threaded_irq in
the rules of context, report and org modes.

Misc:
----
To be consistent with other scripts, change confidence level
of the script to 'Moderate'.

Signed-off-by: Vaishali Thakkar <vaishali.thakkar@oracle.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-12-11 12:08:26 +01:00
Vaishali Thakkar
35b303ae36 Coccinelle: misc: Improve the result given by context mode
To eliminate false positives given by the context mode, add
necessary arguments for the function request_threaded_irq.

Signed-off-by: Vaishali Thakkar <vaishali.thakkar@oracle.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-12-11 12:08:26 +01:00
Vaishali Thakkar
dca24c4544 Coccinelle: misc: Improve the matching of rules
Currently because of the left associativity of the operators, pattern
IRQF_ONESHOT | flags does not match with the pattern when we have more
than one flag after the disjunction. This eventually results in giving
false positives by the script. This patch eliminates these FPs by
improving the rule.

Signed-off-by: Vaishali Thakkar <vaishali.thakkar@oracle.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-12-11 12:08:26 +01:00
Anton Tikhomirov
51a5f81079 kbuild/mkspec: avoid using brace expansion
Brace expansion might not work properly if _buildshell RPM macro
points to a shell other than bash. Particularly, with _bulidshell
defined to /bin/dash it leads to broken build and source symlinks.

Signed-off-by: Anton Tikhomirov <anton.tikhomirov@cdnetworks.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-12-11 12:07:00 +01:00
Andrew F. Davis
75238b9e6a Coccinelle: Add misc/boolconv.cocci
Add a script to check for unneeded conversions to bool.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-12-11 12:07:00 +01:00
Nicolas Pitre
76bee23411 kbuild: cmd_export_list: tighten the sed script
When LTO is used, some ___ksymtab_string sections are seen by this sed
script, creating lines containing a single ) such as:

EXPORT(foo)
)
)
EXPORT(bar)

Let's make it so the + character is also required for any line to be
printed.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-12-11 11:51:43 +01:00
Mauro Carvalho Chehab
f15c323397 scripts: add a script to check if Documentation/00-INDEX is sane
It is easy to forget adding/removing entries at the
Documentation/00-INDEX file. In a matter of fact, even before
ReST conversion, people use to forget adding things here, as
there are lots of missing stuff out there.

Now that we're doing a hard work converting entries to ReST,
and while this hole file is not outdated, it is good to have
some tool that would help to verify that this file is kept
updated.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2016-12-05 14:21:24 -07:00
Nicolas Pitre
d3fc425e81 kbuild: make sure autoksyms.h exists early
Some people are able to trigger a race where autoksyms.h is used before
its empty version is even created.  Let's create it at the same time as
the directory holding it is created.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Prarit Bhargava <prarit@redhat.com>
Tested-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-01 10:19:22 -08:00
Nicholas Piggin
abac4c8973 kbuild: minor improvement for thin archives build
The root built-in.o archive is currently generated before all object
files are built for the final link, due to final build of init/ after
version update. In practice it seems like it doesn't matter because
the archive symbol table does not change, but it is more logical to
create the final archive as the last step.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-11-29 15:58:57 +01:00
Nicholas Piggin
d8c1eb86e9 kbuild: modpost warn if export version crc is missing
This catches the failing ceph CRC on with:

    LD      vmlinux.o
    MODPOST vmlinux.o
  WARNING: EXPORT symbol "ceph_monc_do_statfs" [vmlinux] version
  generation failed, symbol will not be versioned.

When the modules referring to exported symbols are built, there is an
existing warning for missing CRC, but it's not always the case such
any such module will be built, and in any case it is useful to get a
warning at the source.

This gets a little verbose with CONFIG_DEBUG_SECTION_MISMATCH,
producing a warning with each object linked, but I didn't think
that warranted extra complexity to avoid.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-11-29 15:58:57 +01:00
Nicholas Piggin
9da2f584b5 kbuild: improve linker compatibility with lib-ksyms.o build
lib-ksyms.o is created by linking an empty input file with a linker
script containing the interesting bits. Currently the empty input file
is an archive containing nothing, however this causes the gold linker
to segfault.

I have opened a bug against gold

  https://sourceware.org/bugzilla/show_bug.cgi?id=20767

However this can be worked around by assembling an empty file to link
with instead. The resulting lib-ksyms.o is slightly larger (seemingly
due to empty .text, .data, .bss setions added), but final linked
output should not be changed.

Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-11-29 15:58:57 +01:00
Michal Marek
7e441fe759 genksyms: Regenerate parser
Regenerate the keyword table and parser after commit 0efdb2282343
("kbuild/genksyms: handle va_list type").

Signed-off-by: Michal Marek <mmarek@suse.com>
2016-11-29 15:57:40 +01:00
Nicholas Piggin
0efdb22823 kbuild/genksyms: handle va_list type
genksyms currently does not handle va_list. Add the __builtin_va_list
keyword as a type. This reduces the amount of syntax errors thrown,
but so far no export symbol has a type with a va_list argument, so
there is currently no bug in the end result.

Note: this patch does not regenerate shipped parser files.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-11-29 15:53:19 +01:00
Nicholas Piggin
fe026a851b kbuild: thin archives for multi-y targets
THIN_ARCHIVES builds archives for built-in.o targets, have it build
multi-y targets as archives as well.

This saves another ~15% of the size of intermediate artifacts in the
build tree. After this patch, the linker is only used in final link,
and special cases like vdsos.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-11-29 15:53:19 +01:00
Nicholas Piggin
7e2b37c971 kbuild: kallsyms allow 3-pass generation if symbols size has changed
kallsyms generation is not foolproof, due to some linkers adding
symbols (e.g., branch trampolines) when a binary size changes.
Have it attempt a 3rd pass automatically if the kallsyms size changes
in the 2nd pass.

This allows powerpc64 allyesconfig to build without adding another
pass when it's not required.

This can be solved other ways by directing the linker not to add labels
on branch stubs, or to move kallsyms near the end of the image. The
former is undesirable for debugging/tracing, and the latter is a more
significant change that requires more testing and review.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-11-29 15:53:19 +01:00
Josh Poimboeuf
53938ee427 scripts/decode_stacktrace.sh: Fix address line detection on x86
Kirill reported that the decode_stacktrace.sh script was broken by the
following commit:

  bb5e5ce545f2 ("x86/dumpstack: Remove kernel text addresses from stack dump")

Fix it by updating the per-line absolute address check to also check for
function-based address lines like the following:

  write_sysrq_trigger+0x51/0x60

I didn't remove the check for absolute addresses because it's still
needed for ARM.

Reported-by: Kirill A. Shutemov <kirill@shutemov.name>
Tested-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <alexander.levin@verizon.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: bb5e5ce545f2 ("x86/dumpstack: Remove kernel text addresses from stack dump")
Link: http://lkml.kernel.org/r/20161128230635.4n2ofgawltgexgcg@treble
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-29 14:19:50 +01:00
Cheah Kok Cheong
0eb4734696 Scripts: kconfig: nconf: fix _GNU_SOURCE redefined warning
Fix below warning when make nconfig is run initially
or after make clean.

  HOSTCC  scripts/kconfig/nconf.o
scripts/kconfig/nconf.c:8:0: warning: "_GNU_SOURCE" redefined
 #define _GNU_SOURCE
 ^
<command-line>:0:0: note: this is the location of the previous definition

Signed-off-by: Cheah Kok Cheong <thrust73@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-11-29 14:03:14 +01:00
Heinrich Schuchardt
c7d47f26df modpost: free allocated memory
valgrind complains that memory is not freed after allocation
with realloc() called from main() and write_dump().

So let us free the allocated memory properly.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Link: http://lkml.kernel.org/r/1470166981-6461-1-git-send-email-xypron.glpk@gmx.de
Signed-off-by: Jessica Yu <jeyu@redhat.com>
2016-11-26 11:18:01 -08:00
Adam Borowski
152b695d74 builddeb: fix cross-building to arm64 producing host-arch debs
Both Debian and kernel archs are "arm64" but UTS_MACHINE and gcc say
"aarch64".  Recognizing just the latter should be enough but let's
accept both in case something regresses again or an user sets
UTS_MACHINE=arm64.

Regressed in cfa88c7: arm64: Set UTS_MACHINE in the Makefile.

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Acked-by: Riku Voipio <riku.voipio@linaro.org>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-11-25 15:39:03 +01:00
Ingo Molnar
02cb689b2c Merge branch 'linus' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-22 12:37:38 +01:00
Linus Torvalds
04e36857d6 Merge branch 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild fixes from Michal Marek:
 "Here are some regression fixes for kbuild:

   - modversion support for exported asm symbols (Nick Piggin). The
     affected architectures need separate patches adding
     asm-prototypes.h.

   - fix rebuilds of lib-ksyms.o (Nick Piggin)

   - -fno-PIE builds (Sebastian Siewior and Borislav Petkov). This is
     not a kernel regression, but one of the Debian gcc package.
     Nevertheless, it's quite annoying, so I think it should go into
     mainline and stable now"

* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild: Steal gcc's pie from the very beginning
  kbuild: be more careful about matching preprocessed asm ___EXPORT_SYMBOL
  x86/kexec: add -fno-PIE
  scripts/has-stack-protector: add -fno-PIE
  kbuild: add -fno-PIE
  kbuild: modversions for EXPORT_SYMBOL() for asm
  kbuild: prevent lib-ksyms.o rebuilds
2016-11-18 16:45:21 -08:00
Jonathan Corbet
917fef6f7e Linux 4.9-rc4
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 p/izdpTbrw3GX6xXB8olbG7XWHaVye/+TT3q6+gmgm8I/QEujcLeGoycE0zlhPN8
 FG/JX76At/+ZM2Py7Oxo3k+oKL9CHrtOQYDp/wN0uslV5eYvvkZz0/M1HMOGZt+c
 gZU5jzM17K7C4Nzo06WAuBU9wUBGc25m+cPicLlOmljnzfU+f50SKaDjZq3p7QI=
 =2KUF
 -----END PGP SIGNATURE-----

Merge tag 'v4.9-rc4' into sound

Bring in -rc4 patches so I can successfully merge the sound doc changes.
2016-11-18 16:13:41 -07:00
Ingo Molnar
89a01c51cb Merge branch 'x86/cpufeature' into x86/asm, to pick up dependency
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-17 08:30:54 +01:00
Jani Nikula
0c9aa20957 kernel-doc: add support for one line inline struct member doc comments
kernel-doc supports documenting struct members "inline" since
a4c6ebede2f9 ("scripts/kernel-doc Allow struct arguments documentation
in struct body"). This requires the inline kernel-doc comments to have
the opening and closing comment markers (/** and */ respectively) on
lines of their own, even for short comments. For example:

	/**
	 * struct foo - struct documentation
	 */
	struct foo {
		/**
		 * @bar: member documentation
		 */
		int bar;
	};

Add support for one line inline comments:

	/**
	 * struct foo - struct documentation
	 */
	struct foo {
		/** @bar: member documentation */
		int bar;
	};

Note that mixing of the two in one doc comment is not allowed; either
both comment markers must be on lines of their own, or both must be on
the one line. This limitation keeps both the comments more uniform, and
kernel-doc less complicated.

Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2016-11-16 16:30:27 -07:00
Nicolas Pitre
32ce5ac867 Kconfig: Regenerate *.c_shipped files after previous changes
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: linux-kbuild@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Michal Marek <mmarek@suse.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Edward Cree <ecree@solarflare.com>
Link: http://lkml.kernel.org/r/1478841010-28605-3-git-send-email-nicolas.pitre@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-16 09:26:33 +01:00
Nicolas Pitre
237e3ad0f1 Kconfig: Introduce the "imply" keyword
The "imply" keyword is a weak version of "select" where the target
config symbol can still be turned off, avoiding those pitfalls that come
with the "select" keyword.

This is useful e.g. with multiple drivers that want to indicate their
ability to hook into a secondary subsystem while allowing the user to
configure that subsystem out without also having to unset these drivers.

Currently, the same effect can almost be achieved with:

config DRIVER_A
	tristate

config DRIVER_B
	tristate

config DRIVER_C
	tristate

config DRIVER_D
	tristate

[...]

config SUBSYSTEM_X
	tristate
	default DRIVER_A || DRIVER_B || DRIVER_C || DRIVER_D || [...]

This is unwieldy to maintain especially with a large number of drivers.
Furthermore, there is no easy way to restrict the choice for SUBSYSTEM_X
to y or n, excluding m, when some drivers are built-in. The "select"
keyword allows for excluding m, but it excludes n as well. Hence
this "imply" keyword.  The above becomes:

config DRIVER_A
	tristate
	imply SUBSYSTEM_X

config DRIVER_B
	tristate
	imply SUBSYSTEM_X

[...]

config SUBSYSTEM_X
	tristate

This is much cleaner, and way more flexible than "select". SUBSYSTEM_X
can still be configured out, and it can be set as a module when none of
the drivers are configured in or all of them are modular.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: linux-kbuild@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: Michal Marek <mmarek@suse.com>
Cc: Edward Cree <ecree@solarflare.com>
Link: http://lkml.kernel.org/r/1478841010-28605-2-git-send-email-nicolas.pitre@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-16 09:26:33 +01:00
Peter Zijlstra
0f5225b024 locking/mutex, drm: Introduce mutex_trylock_recursive()
By popular DRM demand, introduce mutex_trylock_recursive() to fix up the
two GEM users.

Without this it is very easy for these drivers to get stuck in
low-memory situations and trigger OOM. Work is in progress to remove the
need for this in at least i915.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Jason Low <jason.low2@hpe.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Terry Rudd <terry.rudd@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <Will.Deacon@arm.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-15 14:19:55 +01:00
Stephen Boyd
9648dc1577 recordmcount: arm: Implement make_nop
In similar spirit to x86 and arm64 support, add a make_nop_arm()
to replace calls to mcount with a nop in sections that aren't
traced.

Link: http://lkml.kernel.org/r/20161018234200.5804-1-sboyd@codeaurora.org

Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-14 16:43:00 -05:00
Greg Kroah-Hartman
b7d91c9152 Merge 4.9-rc5 into char-misc-next
We want those fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-14 16:39:47 +01:00
Nicholas Piggin
5b9ff02785 powerpc: Build-time sort the exception table
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-14 11:11:51 +11:00
Linus Torvalds
015ed9433b Merge branch 'maybe-uninitialized' (patches from Arnd)
Merge fixes for -Wmaybe-uninitialized from Arnd Bergmann:
 "It took a while for some patches to make it into mainline through
  maintainer trees, but the 28-patch series is now reduced to 10, with
  one tiny patch added at the end.

  Aside from patches that are no longer required, I did these changes
  compared to version 1:

   - Dropped "iio: maxim_thermocouple: detect invalid storage size in
     read()", which is currently in linux-next as commit 32cb7d27e65d.
     This is the only remaining warning I see for a couple of corner
     cases (kbuild bot reports it on blackfin, kernelci bot and arm-soc
     bot both report it on arm64)

   - Dropped "brcmfmac: avoid maybe-uninitialized warning in
     brcmf_cfg80211_start_ap", which is currently in net/master merge
     pending.

   - Dropped two x86 patches, "x86: math-emu: possible uninitialized
     variable use" and "x86: mark target address as output in 'insb'
     asm" as they do not seem to trigger for a default build, and I got
     no feedback on them. Both of these are ancient issues and seem
     harmless, I will send them again to the x86 maintainers once the
     rest is merged.

   - Dropped "rbd: false-postive gcc-4.9 -Wmaybe-uninitialized" based on
     feedback from Ilya Dryomov, who already has a different fix queued
     up for v4.10. The kbuild bot reports this as a warning for xtensa.

   - Replaced "crypto: aesni: avoid -Wmaybe-uninitialized warning" with
     a simpler patch, this one always triggers but my first solution
     would not be safe for linux-4.9 any more at this point. I'll follow
     up with the larger patch as a cleanup for 4.10.

   - Replaced "dib0700: fix nec repeat handling" with a better one,
     contributed by Sean Young"

* -Wmaybe-uninitialized fixes:
  Kbuild: enable -Wmaybe-uninitialized warnings by default
  pcmcia: fix return value of soc_pcmcia_regulator_set
  infiniband: shut up a maybe-uninitialized warning
  crypto: aesni: shut up -Wmaybe-uninitialized warning
  rc: print correct variable for z8f0811
  dib0700: fix nec repeat handling
  s390: pci: don't print uninitialized data for debugging
  nios2: fix timer initcall return value
  x86: apm: avoid uninitialized data
  NFSv4.1: work around -Wmaybe-uninitialized warning
  Kbuild: enable -Wmaybe-uninitialized warning for "make W=1"
2016-11-11 10:03:01 -08:00
Arnd Bergmann
4324cb23f4 Kbuild: enable -Wmaybe-uninitialized warnings by default
Previously the warnings were added back at the W=1 level and above, this
now turns them on again by default, assuming that we have addressed all
warnings and again have a clean build for v4.10.

I found a number of new warnings in linux-next already and submitted
bugfixes for those.  Hopefully they are caught by the 0day builder in
the future as soon as this patch is merged.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-11 08:45:08 -08:00
Arnd Bergmann
a76bcf557e Kbuild: enable -Wmaybe-uninitialized warning for "make W=1"
Traditionally, we have always had warnings about uninitialized variables
enabled, as this is part of -Wall, and generally a good idea [1], but it
also always produced false positives, mainly because this is a variation
of the halting problem and provably impossible to get right in all cases
[2].

Various people have identified cases that are particularly bad for false
positives, and in commit e74fc973b6e5 ("Turn off -Wmaybe-uninitialized
when building with -Os"), I turned off the warning for any build that
was done with CC_OPTIMIZE_FOR_SIZE.  This drastically reduced the number
of false positive warnings in the default build but unfortunately had
the side effect of turning the warning off completely in 'allmodconfig'
builds, which in turn led to a lot of warnings (both actual bugs, and
remaining false positives) to go in unnoticed.

With commit 877417e6ffb9 ("Kbuild: change CC_OPTIMIZE_FOR_SIZE
definition") enabled the warning again for allmodconfig builds in v4.7
and in v4.8-rc1, I had finally managed to address all warnings I get in
an ARM allmodconfig build and most other maybe-uninitialized warnings
for ARM randconfig builds.

However, commit 6e8d666e9253 ("Disable "maybe-uninitialized" warning
globally") was merged at the same time and disabled it completely for
all configurations, because of false-positive warnings on x86 that I had
not addressed until then.  This caused a lot of actual bugs to get
merged into mainline, and I sent several dozen patches for these during
the v4.9 development cycle.  Most of these are actual bugs, some are for
correct code that is safe because it is only called under external
constraints that make it impossible to run into the case that gcc sees,
and in a few cases gcc is just stupid and finds something that can
obviously never happen.

I have now done a few thousand randconfig builds on x86 and collected
all patches that I needed to address every single warning I got (I can
provide the combined patch for the other warnings if anyone is
interested), so I hope we can get the warning back and let people catch
the actual bugs earlier.

This reverts the change to disable the warning completely and for now
brings it back at the "make W=1" level, so we can get it merged into
mainline without introducing false positives.  A follow-up patch enables
it on all levels unless some configuration option turns it off because
of false-positives.

Link: https://rusty.ozlabs.org/?p=232 [1]
Link: https://gcc.gnu.org/wiki/Better_Uninitialized_Warnings [2]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-11 08:45:08 -08:00
Alexey Dobriyan
eef06b82f1 scripts/bloat-o-meter: fix SIGPIPE
Fix piping output to a program which quickly exits (read: head -n1)

	$ ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux | head -n1
	add/remove: 0/0 grow/shrink: 9/60 up/down: 124/-305 (-181)
	close failed in file object destructor:
	sys.excepthook is missing
	lost sys.stderr

Link: http://lkml.kernel.org/r/20161028204618.GA29923@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-11 08:12:37 -08:00
Nicholas Piggin
cc6acc11ca kbuild: be more careful about matching preprocessed asm ___EXPORT_SYMBOL
The CRC code for asm exports grabs the preprocessed asm, finds the
___EXPORT_SYMBOL and turns those into EXPORT_SYMBOL in a C program
that can be preprocessed and parsed to create the CRC signatures from
the type.

The existing regex matching and replacement is too strict, and doesn't
deal well with whitespace among other things. The line
" EXPORT_SYMBOL(sym)" in a .S file would not match due to initial
whitespace, for example, which resulted in x86's ___preempt_schedule
failing to get CRCs.

Reported-by: Philip Müller <philm@manjaro.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-11-09 22:29:53 +01:00
Sebastian Andrzej Siewior
82031ea29e scripts/has-stack-protector: add -fno-PIE
Adding -no-PIE to the fstack protector check. -no-PIE was introduced
before -fstack-protector so there is no need for a runtime check.

Without it the build stops:
|Cannot use CONFIG_CC_STACKPROTECTOR_STRONG: -fstack-protector-strong available but compiler is broken

due to -mcmodel=kernel + -fPIE if -fPIE is enabled by default.

Tagging it stable so it is possible to compile recent stable kernels as
well.

Cc: stable@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-11-09 22:28:05 +01:00
Nicholas Piggin
4efca4ed05 kbuild: modversions for EXPORT_SYMBOL() for asm
Allow architectures to create asm/asm-prototypes.h file that
provides C prototypes for exported asm functions, which enables
proper CRC versions to be generated for them.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-11-01 16:20:17 +01:00
Kees Cook
58bea4144d latent_entropy: Fix wrong gcc code generation with 64 bit variables
The stack frame size could grow too large when the plugin used long long
on 32-bit architectures when the given function had too many basic blocks.

The gcc warning was:

drivers/pci/hotplug/ibmphp_ebda.c: In function 'ibmphp_access_ebda':
drivers/pci/hotplug/ibmphp_ebda.c:409:1: warning: the frame size of 1108 bytes is larger than 1024 bytes [-Wframe-larger-than=]

This switches latent_entropy from u64 to unsigned long.

Thanks to PaX Team and Emese Revfy for the patch.

Signed-off-by: Kees Cook <keescook@chromium.org>
2016-10-31 11:30:41 -07:00
Kees Cook
da7389ac6c gcc-plugins: Export symbols needed by gcc
This explicitly exports symbols that gcc expects from plugins.

Based on code from Emese Revfy.

Signed-off-by: Kees Cook <keescook@chromium.org>
2016-10-31 10:40:13 -07:00
Silvio Fricke
c950a1739e kernel-doc: better parsing of named variable arguments
Without this patch we get warnings for named variable arguments.

    warning: No description found for parameter '...'
    warning: Excess function parameter 'args' description in 'alloc_ordered_workqueue'

Signed-off-by: Silvio Fricke <silvio.fricke@gmail.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2016-10-28 10:54:16 -06:00
Valentin Rothberg
0d18c19288 checkkconfigsymbols.py: support git's "^" syntax
Support git's "^" syntax for diffing two commits, for instance via
"--diff HEAD^^^..HEAD".

Signed-off-by: Michael Ellermann <mpe@ellerman.id.au>
Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-28 08:12:14 -04:00
Josh Poimboeuf
efdb4167e6 scripts/faddr2line: Fix "size mismatch" error
I'm not sure how we missed this problem before.  When I take a function
address and size from an oops and give it to faddr2line, it usually
complains about a size mismatch:

  $ scripts/faddr2line ~/k/vmlinux write_sysrq_trigger+0x51/0x60
  skipping write_sysrq_trigger address at 0xffffffff815731a1 due to size mismatch (0x60 != 83)
  no match for write_sysrq_trigger+0x51/0x60

The problem is caused by differences in how kallsyms and faddr2line
determine a function's size.

kallsyms calculates a function's size by parsing the output of 'nm -n'
and subtracting the next function's address from the current function's
address.  This means that nop instructions after the end of the function
are included in the size.

In contrast, faddr2line reads the size from the symbol table, which does
*not* include the ending nops in the function's size.

Change faddr2line to calculate the size from the output of 'nm -n' to be
consistent with kallsyms and oops outputs.

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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/bd313ed7c4003f6b1fda63e825325c44a9d837de.1477405374.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-25 18:40:37 +02:00
Mauro Carvalho Chehab
8c27ceff36 docs: fix locations of several documents that got moved
The previous patch renamed several files that are cross-referenced
along the Kernel documentation. Adjust the links to point to
the right places.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-10-24 08:12:35 -02:00
Nicholas Piggin
989cea5c14 kbuild: prevent lib-ksyms.o rebuilds
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reported-by: Russell King <rmk+kernel@armlinux.org.uk>
Tested-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-10-22 21:49:30 +02:00
Linus Torvalds
9ffc66941d This adds a new gcc plugin named "latent_entropy". It is designed to
extract as much possible uncertainty from a running system at boot time as
 possible, hoping to capitalize on any possible variation in CPU operation
 (due to runtime data differences, hardware differences, SMP ordering,
 thermal timing variation, cache behavior, etc).
 
 At the very least, this plugin is a much more comprehensive example for
 how to manipulate kernel code using the gcc plugin internals.
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Merge tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull gcc plugins update from Kees Cook:
 "This adds a new gcc plugin named "latent_entropy". It is designed to
  extract as much possible uncertainty from a running system at boot
  time as possible, hoping to capitalize on any possible variation in
  CPU operation (due to runtime data differences, hardware differences,
  SMP ordering, thermal timing variation, cache behavior, etc).

  At the very least, this plugin is a much more comprehensive example
  for how to manipulate kernel code using the gcc plugin internals"

* tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  latent_entropy: Mark functions with __latent_entropy
  gcc-plugins: Add latent_entropy plugin
2016-10-15 10:03:15 -07:00
Linus Torvalds
50cff89837 Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull misc kbuild changes from Michal Marek:
 "Just a few patches on the kbuild.git#misc branch this time:

   - New Coccinelle patch by Nicholas Mc Guire
   - Existing patch fixes by Julia Lawall
   - Minor comment fix by Markus Elfring"

* 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  Coccinelle: flag conditions with no effect
  scripts/coccicheck: Update reference for the corresponding documentation
  Coccinelle: pm_runtime: ensure relevance of pm_runtime reports
  Coccinelle: limit memdup_user transformation to GFP_KERNEL case
2016-10-14 15:03:08 -07:00
Linus Torvalds
84d69848c9 Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild updates from Michal Marek:

 - EXPORT_SYMBOL for asm source by Al Viro.

   This does bring a regression, because genksyms no longer generates
   checksums for these symbols (CONFIG_MODVERSIONS). Nick Piggin is
   working on a patch to fix this.

   Plus, we are talking about functions like strcpy(), which rarely
   change prototypes.

 - Fixes for PPC fallout of the above by Stephen Rothwell and Nick
   Piggin

 - fixdep speedup by Alexey Dobriyan.

 - preparatory work by Nick Piggin to allow architectures to build with
   -ffunction-sections, -fdata-sections and --gc-sections

 - CONFIG_THIN_ARCHIVES support by Stephen Rothwell

 - fix for filenames with colons in the initramfs source by me.

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (22 commits)
  initramfs: Escape colons in depfile
  ppc: there is no clear_pages to export
  powerpc/64: whitelist unresolved modversions CRCs
  kbuild: -ffunction-sections fix for archs with conflicting sections
  kbuild: add arch specific post-link Makefile
  kbuild: allow archs to select link dead code/data elimination
  kbuild: allow architectures to use thin archives instead of ld -r
  kbuild: Regenerate genksyms lexer
  kbuild: genksyms fix for typeof handling
  fixdep: faster CONFIG_ search
  ia64: move exports to definitions
  sparc32: debride memcpy.S a bit
  [sparc] unify 32bit and 64bit string.h
  sparc: move exports to definitions
  ppc: move exports to definitions
  arm: move exports to definitions
  s390: move exports to definitions
  m68k: move exports to definitions
  alpha: move exports to actual definitions
  x86: move exports to actual definitions
  ...
2016-10-14 14:26:58 -07:00
Mathieu Maret
d0c75f33f0 scripts/tags.sh: enable code completion in VIM
Vim, with the omnicppcomplete(#1) plugin, can do code completion using
information build by ctags.  Add flags needed by omnicppcomplete(#2) to
have completion on member of structure.

1: https://github.com/vim-scripts/omnicppcomplete
2: https://github.com/vim-scripts/OmniCppComplete/blob/master/doc/omnicppcomplete.txt#L93

Link: http://lkml.kernel.org/r/20160830191546.4469-1-mathieu.maret@gmail.com
Signed-off-by: Mathieu Maret <mathieu.maret@gmail.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:33 -07:00