=== Background ===
- Visible n-valued bool/tristate symbols generate a
'# CONFIG_FOO is not set' line in the .config file. The idea is to
remember the user selection without having to set a Makefile
variable. Having n correspond to the variable being undefined in the
Makefiles makes for easy CONFIG_* tests.
- Invisible n-valued bool/tristate symbols normally do not generate a
'# CONFIG_FOO is not set' line, because user values from .config
files have no effect on invisible symbols anyway.
Currently, there is one exception to this rule: Any bool/tristate symbol
that gets the value n through a 'default' property generates a
'# CONFIG_FOO is not set' line, even if the symbol is invisible.
Note that this only applies to explicitly given defaults, and not when
the symbol implicitly defaults to n (like bool/tristate symbols without
'default' properties do).
This is inconsistent, and seems redundant:
- As mentioned, the '# CONFIG_FOO is not set' won't affect the symbol
once the .config is read back in.
- Even if the symbol is invisible at first but becomes visible later,
there shouldn't be any harm in recalculating the default value
rather than viewing the '# CONFIG_FOO is not set' as a previous
user value of n.
=== Changes ===
Change sym_calc_value() to only set SYMBOL_WRITE (write to .config) for
non-n-valued 'default' properties.
Note that SYMBOL_WRITE is always set for visible symbols regardless of whether
they have 'default' properties or not, so this change only affects invisible
symbols.
This reduces the size of the x86 .config on my system by about 1% (due
to removed '# CONFIG_FOO is not set' entries).
One side effect of (and the main motivation for) this change is making
the following two definitions behave exactly the same:
config FOO
bool
config FOO
bool
default n
With this change, neither of these will generate a
'# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied).
That might make it clearer to people that a bare 'default n' is
redundant.
This change only affects generated .config files and not autoconf.h:
autoconf.h only includes #defines for non-n bool/tristate symbols.
=== Testing ===
The following testing was done with the x86 Kconfigs:
- .config files generated before and after the change were compared to
verify that the only difference is some '# CONFIG_FOO is not set'
entries disappearing. A couple of these were inspected manually, and
most turned out to be from redundant 'default n/def_bool n'
properties.
- The generated include/generated/autoconf.h was compared before and
after the change and verified to be identical.
- As a sanity check, the same modification was done to Kconfiglib.
The Kconfiglib test suite was then run to check for any mismatches
against the output of the C implementation.
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Surprisingly or not, disabling a CONFIG option (which is assumed to
be unneeded) may be not so trivial. Especially it is not trivial, when
this CONFIG option is selected by a dozen of other configs. Before the
moment commit 1ccb271433 ("kconfig: make "Selected by:" and
"Implied by:" readable") popped up in v4.16-rc1, it was an absolute pain
to break down the "Selected by" reverse dependency expression in order
to identify all those configs which select (IOW *do not allow
disabling*) a certain feature (assumed to be not needed).
This patch tries to make one step further by putting at users'
fingertips the revdep top level OR sub-expressions grouped/clustered by
the tristate value they evaluate to. This should allow the users to
directly concentrate on and tackle the _active_ reverse dependencies.
To give some numbers and quantify the complexity of certain reverse
dependencies, assuming commit 617aebe6a9 ("Merge tag
'usercopy-v4.16-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux"), ARCH=arm64
and vanilla arm64 defconfig, here is the top 10 CONFIG options with
the highest amount of top level "||" sub-expressions/tokens that make
up the final "Selected by" reverse dependency expression.
| Config | All revdep | Active revdep |
|-------------------|------------|---------------|
| REGMAP_I2C | 212 | 9 |
| CRC32 | 167 | 25 |
| FW_LOADER | 128 | 5 |
| MFD_CORE | 124 | 9 |
| FB_CFB_IMAGEBLIT | 114 | 2 |
| FB_CFB_COPYAREA | 111 | 2 |
| FB_CFB_FILLRECT | 110 | 2 |
| SND_PCM | 103 | 2 |
| CRYPTO_HASH | 87 | 19 |
| WATCHDOG_CORE | 86 | 6 |
The story behind the above is that users need to visually
review/evaluate 212 expressions which *potentially* select REGMAP_I2C
in order to identify the expressions which *actually* select REGMAP_I2C,
for a particular ARCH and for a particular defconfig used.
To make this experience smoother, change the way reverse dependencies
are displayed to the user from [1] to [2].
[1] Old representation of DMA_ENGINE_RAID:
Selected by:
- AMCC_PPC440SPE_ADMA [=n] && DMADEVICES [=y] && (440SPe || 440SP)
- BCM_SBA_RAID [=m] && DMADEVICES [=y] && (ARM64 [=y] || ...
- FSL_RAID [=n] && DMADEVICES [=y] && FSL_SOC && ...
- INTEL_IOATDMA [=n] && DMADEVICES [=y] && PCI [=y] && X86_64
- MV_XOR [=n] && DMADEVICES [=y] && (PLAT_ORION || ARCH_MVEBU [=y] ...
- MV_XOR_V2 [=y] && DMADEVICES [=y] && ARM64 [=y]
- XGENE_DMA [=n] && DMADEVICES [=y] && (ARCH_XGENE [=y] || ...
- DMATEST [=n] && DMADEVICES [=y] && DMA_ENGINE [=y]
[2] New representation of DMA_ENGINE_RAID:
Selected by [y]:
- MV_XOR_V2 [=y] && DMADEVICES [=y] && ARM64 [=y]
Selected by [m]:
- BCM_SBA_RAID [=m] && DMADEVICES [=y] && (ARM64 [=y] || ...
Selected by [n]:
- AMCC_PPC440SPE_ADMA [=n] && DMADEVICES [=y] && (440SPe || ...
- FSL_RAID [=n] && DMADEVICES [=y] && FSL_SOC && ...
- INTEL_IOATDMA [=n] && DMADEVICES [=y] && PCI [=y] && X86_64
- MV_XOR [=n] && DMADEVICES [=y] && (PLAT_ORION || ARCH_MVEBU [=y] ...
- XGENE_DMA [=n] && DMADEVICES [=y] && (ARCH_XGENE [=y] || ...
- DMATEST [=n] && DMADEVICES [=y] && DMA_ENGINE [=y]
Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This commit splits out the special E_OR handling ('-' instead of '||')
into a dedicated helper expr_print_revdev().
Restore the original expr_print() prior to commit 1ccb271433
("kconfig: make "Selected by:" and "Implied by:" readable").
This makes sense because:
- We need to chop those expressions only when printing the reverse
dependency, and only when E_OR is encountered
- Otherwise, it should be printed as before, so fall back to
expr_print()
This also improves the behavior; for a single line, it was previously
displayed in the same line as "Selected by", like this:
Selected by: A [=n] && B [=n]
This will be displayed in a new line, consistently:
Selected by:
- A [=n] && B [=n]
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
IMO, we should discourage '---help---' for new help texts, even in cases
where it would be consistent with other help texts in the file. This
will help if we ever want to get rid of '---help---' in the future.
Also simplify the code to only check for exactly '---help---'. Since
commit c2264564df ("kconfig: warn of unhandled characters in Kconfig
commands"), '---help---' is a proper keyword and can only appear in that
form. Prior to that commit, '---help---' working was more of a syntactic
quirk.
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Currently, only Kconfig symbols are checked for a missing or short help
text, and are only checked if they are defined with the 'config'
keyword.
To make the check more general, extend it to also check help texts for
choices and for symbols defined with the 'menuconfig' keyword.
This increases the accuracy of the check for symbols that would already
have been checked as well, since e.g. a 'menuconfig' symbol after a help
text will be recognized as ending the preceding symbol/choice
definition.
To increase the accuracy of the check further, also recognize 'if',
'endif', 'menu', 'endmenu', 'endchoice', and 'source' as ending a
symbol/choice definition.
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
The check for a missing or short help text only considers symbols with a
prompt, but doesn't recognize any of the following as a prompt:
bool 'foo'
tristate 'foo'
prompt "foo"
prompt 'foo'
Make the check recognize those too.
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
cmd_dt_S_dtb constructs the assembly source to incorporate a devicetree
FDT (that is, the .dtb file) as binary data in the kernel image. This
assembly source contains labels before and after the binary data. The
label names incorporate the file name of the corresponding .dtb file.
Hyphens are not legal characters in labels, so .dtb files built into the
kernel with hyphens in the file name result in errors like the
following:
bcm3368-netgear-cvg834g.dtb.S: Assembler messages:
bcm3368-netgear-cvg834g.dtb.S:5: Error: : no such section
bcm3368-netgear-cvg834g.dtb.S:5: Error: junk at end of line, first unrecognized character is `-'
bcm3368-netgear-cvg834g.dtb.S:6: Error: unrecognized opcode `__dtb_bcm3368-netgear-cvg834g_begin:'
bcm3368-netgear-cvg834g.dtb.S:8: Error: unrecognized opcode `__dtb_bcm3368-netgear-cvg834g_end:'
bcm3368-netgear-cvg834g.dtb.S:9: Error: : no such section
bcm3368-netgear-cvg834g.dtb.S:9: Error: junk at end of line, first unrecognized character is `-'
Fix this by updating cmd_dt_S_dtb to transform all hyphens from the file
name to underscores when constructing the labels.
As of v4.16-rc2, 1139 .dts files across ARM64, ARM, MIPS and PowerPC
contain hyphens in their names, but the issue only currently manifests
on Broadcom MIPS platforms, as that is the only place where such files
are built into the kernel. For example when CONFIG_DT_NETGEAR_CVG834G=y,
or on BMIPS kernels when the dtbs target is used (in the latter case it
admittedly shouldn't really build all the dtb.o files, but thats a
separate issue).
Fixes: 695835511f ("MIPS: BMIPS: rename bcm96358nb4ser to bcm6358-neufbox4-sercom")
Signed-off-by: James Hogan <jhogan@kernel.org>
Reviewed-by: Frank Rowand <frowand.list@gmail.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: <stable@vger.kernel.org> # 4.9+
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
The bloat-o-meter script has two typos in the help, fix both.
Fixes: 192efb7a1f ("bloat-o-meter: provide 3 different arguments for data, function and All")
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
kconfig.h was excluded from consideration by fixdep by
6a5be57f0f (fixdep: fix extraneous dependencies) to avoid some false
positive hits
(1) include/config/.h
(2) include/config/h.h
(3) include/config/foo.h
(1) occurred because kconfig.h contains the string CONFIG_ in a
comment. However, since dee81e9886 (fixdep: faster CONFIG_ search), we
have a check that the part after CONFIG_ is non-empty, so this does not
happen anymore (and CONFIG_ appears by itself elsewhere, so that check
is worthwhile).
(2) comes from the include guard, __LINUX_KCONFIG_H. But with the
previous patch, we no longer match that either.
That leaves (3), which amounts to one [1] false dependency (aka stat() call
done by make), which I think we can live with:
We've already had one case [2] where the lack of include/linux/kconfig.h in
the .o.cmd file caused a missing rebuild, and while I originally thought
we should just put kconfig.h in the dependency list without parsing it
for the CONFIG_ pattern, we actually do have some real CONFIG_ symbols
mentioned in it, and one can imagine some translation unit that just
does '#ifdef __BIG_ENDIAN' but doesn't through some other header
actually depend on CONFIG_CPU_BIG_ENDIAN - so changing the target
endianness could end up rebuilding the world, minus that small
TU. Quoting Linus,
... when missing dependencies cause a missed re-compile, the resulting
bugs can be _really_ subtle.
[1] well, two, we now also have CONFIG_BOOGER/booger.h - we could change
that to FOO if we care
[2] https://lkml.org/lkml/2018/2/22/838
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
The string CONFIG_ quite often appears after other alphanumerics,
meaning that that instance cannot be referencing a Kconfig
symbol. Omitting these means make has fewer files to stat() when
deciding what needs to be rebuilt - for a defconfig build, this seems to
remove about 2% of the (wildcard ...) lines from the .o.cmd files.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
uml-config.h hasn't existed in this decade (87e299e5c7 - x86, um: get
rid of uml-config.h). The few remaining UML_CONFIG instances are defined
directly in terms of their real CONFIG symbol in common-offsets.h, so
unlike when the symbols got defined via a sed script, anything that uses
UML_CONFIG_FOO now should also automatically pick up a dependency on
CONFIG_FOO via the normal fixdep mechanism (since common-offsets.h
should at least recursively be a dependency). Hence I believe we should
actually be able to ignore the HELLO_CONFIG_BOOM cases.
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Richard Weinberger <richard@nod.at>
Cc: user-mode-linux-devel@lists.sourceforge.net
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
- suppress sparse warnings about unknown attributes
- fix typos and stale comments
- fix build error of arch/sh
- fix wrong use of ld-option vs cc-ldoption
- remove redundant GCC_PLUGINS_CFLAGS assignment
- fix another memory leak of Kconfig
- fix line number in error messages of Kconfig
- do not write confusing CONFIG_DEFCONFIG_LIST out to .config
- add xstrdup() to Kconfig to handle memory shortage errors
- show also a Debian package name if ncurses is missing
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=sr4l
-----END PGP SIGNATURE-----
Merge tag 'kbuild-fixes-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- suppress sparse warnings about unknown attributes
- fix typos and stale comments
- fix build error of arch/sh
- fix wrong use of ld-option vs cc-ldoption
- remove redundant GCC_PLUGINS_CFLAGS assignment
- fix another memory leak of Kconfig
- fix line number in error messages of Kconfig
- do not write confusing CONFIG_DEFCONFIG_LIST out to .config
- add xstrdup() to Kconfig to handle memory shortage errors
- show also a Debian package name if ncurses is missing
* tag 'kbuild-fixes-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
MAINTAINERS: take over Kconfig maintainership
kconfig: fix line number in recursive inclusion error message
Coccinelle: memdup: Fix typo in warning messages
kconfig: Update ncurses package names for menuconfig
kbuild/kallsyms: trivial typo fix
kbuild: test --build-id linker flag by ld-option instead of cc-ldoption
kbuild: drop superfluous GCC_PLUGINS_CFLAGS assignment
kconfig: Don't leak choice names during parsing
sh: fix build error for empty CONFIG_BUILTIN_DTB_SOURCE
kconfig: set SYMBOL_AUTO to the symbol marked with defconfig_list
kconfig: add xstrdup() helper
kbuild: disable sparse warnings about unknown attributes
Makefile: Fix lying comment re. silentoldconfig
When recursive inclusion is detected, the line number of the last
'included from:' is wrong.
[Test Case]
Kconfig:
-------->8--------
source "Kconfig2"
-------->8--------
Kconfig2:
-------->8--------
source "Kconfig3"
-------->8--------
Kconfig3:
-------->8--------
source "Kconfig"
-------->8--------
[Result]
$ make allyesconfig
scripts/kconfig/conf --allyesconfig Kconfig
Kconfig:1: recursive inclusion detected. Inclusion path:
current file : 'Kconfig'
included from: 'Kconfig3:1'
included from: 'Kconfig2:1'
included from: 'Kconfig:3'
scripts/kconfig/Makefile:89: recipe for target 'allyesconfig' failed
make[1]: *** [allyesconfig] Error 1
Makefile:512: recipe for target 'allyesconfig' failed
make: *** [allyesconfig] Error 2
where we expect
current file : 'Kconfig'
included from: 'Kconfig3:1'
included from: 'Kconfig2:1'
included from: 'Kconfig:1'
The 'iter->lineno+1' in the second fpinrtf() should be 'iter->lineno-1'.
I refactored the code to merge the two fprintf() calls.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
The package name is ncurses-devel for Redhat based distros
and libncurses-dev for Debian based distros.
Signed-off-by: Arvind Prasanna <arvindprasanna@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
GCC_PLUGINS_CFLAGS is already in the environment, so it is superfluous
to add it in commandline of final build of init/.
Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
The named choice is not used in the kernel tree, but if it were used,
it would not be freed.
The intention of the named choice can be seen in the log of
commit 5a1aa8a1af ("kconfig: add named choice group").
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
The 'defconfig_list' is a weird attribute. If the '.config' is
missing, conf_read_simple() iterates over all visible defaults,
then it uses the first one for which fopen() succeeds.
config DEFCONFIG_LIST
string
depends on !UML
option defconfig_list
default "/lib/modules/$UNAME_RELEASE/.config"
default "/etc/kernel-config"
default "/boot/config-$UNAME_RELEASE"
default "$ARCH_DEFCONFIG"
default "arch/$ARCH/defconfig"
However, like other symbols, the first visible default is always
written out to the .config file. This might be different from what
has been actually used.
For example, on my machine, the third one "/boot/config-$UNAME_RELEASE"
is opened, like follows:
$ rm .config
$ make oldconfig 2>/dev/null
scripts/kconfig/conf --oldconfig Kconfig
#
# using defaults found in /boot/config-4.4.0-112-generic
#
*
* Restart config...
*
*
* IRQ subsystem
*
Expose irq internals in debugfs (GENERIC_IRQ_DEBUGFS) [N/y/?] (NEW)
However, the resulted .config file contains the first one since it is
visible:
$ grep CONFIG_DEFCONFIG_LIST .config
CONFIG_DEFCONFIG_LIST="/lib/modules/$UNAME_RELEASE/.config"
In order to stop confusing people, prevent this CONFIG option from
being written to the .config file.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
We already have xmalloc(), xcalloc(), and xrealloc((). Add xstrdup()
as well to save tedious error handling.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Disable retpoline validation in objtool if your compiler sucks, and otherwise
select the validation stuff for CONFIG_RETPOLINE=y (most builds would already
have it set due to ORC).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
David allowed retpolines in .init.text, except for modules, which will
trip up objtool retpoline validation, fix that.
Requested-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
David requested a objtool validation pass for CONFIG_RETPOLINE=y enabled
builds, where it validates no unannotated indirect jumps or calls are
left.
Add an additional .discard.retpoline_safe section to allow annotating
the few indirect sites that are required and safe.
Requested-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Makefile changes:
- enable unused-variable warning that was wrongly disabled for clang
Kconfig changes:
- warn blank 'help' and fix existing instances
- fix 'choice' behavior to not write out invisible symbols
- fix misc weirdness
Coccinell changes:
- fix false positive of free after managed memory alloc detection
- improve performance of NULL dereference detection
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=jy5l
-----END PGP SIGNATURE-----
Merge tag 'kbuild-v4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull more Kbuild updates from Masahiro Yamada:
"Makefile changes:
- enable unused-variable warning that was wrongly disabled for clang
Kconfig changes:
- warn about blank 'help' and fix existing instances
- fix 'choice' behavior to not write out invisible symbols
- fix misc weirdness
Coccinell changes:
- fix false positive of free after managed memory alloc detection
- improve performance of NULL dereference detection"
* tag 'kbuild-v4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (21 commits)
kconfig: remove const qualifier from sym_expand_string_value()
kconfig: add xrealloc() helper
kconfig: send error messages to stderr
kconfig: echo stdin to stdout if either is redirected
kconfig: remove check_stdin()
kconfig: remove 'config*' pattern from .gitignnore
kconfig: show '?' prompt even if no help text is available
kconfig: do not write choice values when their dependency becomes n
coccinelle: deref_null: avoid useless computation
coccinelle: devm_free: reduce false positives
kbuild: clang: disable unused variable warnings only when constant
kconfig: Warn if help text is blank
nios2: kconfig: Remove blank help text
arm: vt8500: kconfig: Remove blank help text
MIPS: kconfig: Remove blank help text
MIPS: BCM63XX: kconfig: Remove blank help text
lib/Kconfig.debug: Remove blank help text
Staging: rtl8192e: kconfig: Remove blank help text
Staging: rtl8192u: kconfig: Remove blank help text
mmc: kconfig: Remove blank help text
...
This function returns realloc'ed memory, so the returned pointer
must be passed to free() when done. So, 'const' qualifier is odd.
It is allowed to modify the expanded string.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
We already have xmalloc(), xcalloc(). Add xrealloc() as well
to save tedious error handling.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
These messages should be directed to stderr.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
If stdio is not tty, conf_askvalue() puts additional new line to
prevent prompts from being concatenated into a single line. This
care is missing in conf_choice(), so a 'choice' prompt and the next
prompt are shown in the same line.
Move the code into xfgets() to cater to all cases. To improve this
more, let's echo stdin to stdout. This clarifies what keys were
input from stdio and the stdout looks like as if it were from tty.
I removed the isatty(2) check since stderr is unrelated here.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
Except silentoldconfig, valid_stdin is 1, so check_stdin() is no-op.
oldconfig and silentoldconfig work almost in the same way except that
the latter generates additional files under include/. Both ask users
for input for new symbols.
I do not know why only silentoldconfig requires stdio be tty.
$ rm -f .config; touch .config
$ yes "" | make oldconfig > stdout
$ rm -f .config; touch .config
$ yes "" | make silentoldconfig > stdout
make[1]: *** [silentoldconfig] Error 1
make: *** [silentoldconfig] Error 2
$ tail -n 4 stdout
Console input/output is redirected. Run 'make oldconfig' to update configuration.
scripts/kconfig/Makefile:40: recipe for target 'silentoldconfig' failed
Makefile:507: recipe for target 'silentoldconfig' failed
Redirection is useful, for example, for testing where we want to give
particular key inputs from a test file, then check the result.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
I could not figure out why this pattern should be ignored.
Checking commit 1e65174a33 ("Add some basic .gitignore files")
did not help.
Let's remove this pattern, then see if it is really needed.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
'make config', 'make oldconfig', etc. always receive '?' as a valid
input and show useful information even if no help text is available.
------------------------>8------------------------
foo (FOO) [N/y] (NEW) ?
There is no help available for this option.
Symbol: FOO [=n]
Type : bool
Prompt: foo
Defined at Kconfig:1
------------------------>8------------------------
However, '?' is not shown in the prompt if its help text is missing.
Let's show '?' all the time so that the prompt and the behavior match.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
"# CONFIG_... is not set" for choice values are wrongly written into
the .config file if they are once visible, then become invisible later.
Test case
---------
---------------------------(Kconfig)----------------------------
config A
bool "A"
choice
prompt "Choice ?"
depends on A
config CHOICE_B
bool "Choice B"
config CHOICE_C
bool "Choice C"
endchoice
----------------------------------------------------------------
---------------------------(.config)----------------------------
CONFIG_A=y
----------------------------------------------------------------
With the Kconfig and .config above,
$ make config
scripts/kconfig/conf --oldaskconfig Kconfig
*
* Linux Kernel Configuration
*
A (A) [Y/n] n
#
# configuration written to .config
#
$ cat .config
#
# Automatically generated file; DO NOT EDIT.
# Linux Kernel Configuration
#
# CONFIG_A is not set
# CONFIG_CHOICE_B is not set
# CONFIG_CHOICE_C is not set
Here,
# CONFIG_CHOICE_B is not set
# CONFIG_CHOICE_C is not set
should not be written into the .config file because their dependency
"depends on A" is unmet.
Currently, there is no code that clears SYMBOL_WRITE of choice values.
Clear SYMBOL_WRITE for all symbols in sym_calc_value(), then set it
again after calculating visibility. To simplify the logic, set the
flag if they have non-n visibility, regardless of types, and regardless
of whether they are choice values or not.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
The effect of the rules ifm1, pr11, and pr12 is only used in the final rule,
which depends on context && !org && !report. Thus these rules should only
be performed in those circumstances.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Some files use both a non-devm allocation and a devm_allocation. Don't
complain about a free when the same function contains a non-devm
allocation.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
We get a lot of very large stack frames using gcc-7.0.1 with the default
-fsanitize-address-use-after-scope --param asan-stack=1 options, which can
easily cause an overflow of the kernel stack, e.g.
drivers/gpu/drm/i915/gvt/handlers.c:2434:1: warning: the frame size of 46176 bytes is larger than 3072 bytes
drivers/net/wireless/ralink/rt2x00/rt2800lib.c:5650:1: warning: the frame size of 23632 bytes is larger than 3072 bytes
lib/atomic64_test.c:250:1: warning: the frame size of 11200 bytes is larger than 3072 bytes
drivers/gpu/drm/i915/gvt/handlers.c:2621:1: warning: the frame size of 9208 bytes is larger than 3072 bytes
drivers/media/dvb-frontends/stv090x.c:3431:1: warning: the frame size of 6816 bytes is larger than 3072 bytes
fs/fscache/stats.c:287:1: warning: the frame size of 6536 bytes is larger than 3072 bytes
To reduce this risk, -fsanitize-address-use-after-scope is now split out
into a separate CONFIG_KASAN_EXTRA Kconfig option, leading to stack
frames that are smaller than 2 kilobytes most of the time on x86_64. An
earlier version of this patch also prevented combining KASAN_EXTRA with
KASAN_INLINE, but that is no longer necessary with gcc-7.0.1.
All patches to get the frame size below 2048 bytes with CONFIG_KASAN=y
and CONFIG_KASAN_EXTRA=n have been merged by maintainers now, so we can
bring back that default now. KASAN_EXTRA=y still causes lots of
warnings but now defaults to !COMPILE_TEST to disable it in
allmodconfig, and it remains disabled in all other defconfigs since it
is a new option. I arbitrarily raise the warning limit for KASAN_EXTRA
to 3072 to reduce the noise, but an allmodconfig kernel still has around
50 warnings on gcc-7.
I experimented a bit more with smaller stack frames and have another
follow-up series that reduces the warning limit for 64-bit architectures
to 1280 bytes (without CONFIG_KASAN).
With earlier versions of this patch series, I also had patches to address
the warnings we get with KASAN and/or KASAN_EXTRA, using a
"noinline_if_stackbloat" annotation.
That annotation now got replaced with a gcc-8 bugfix (see
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715) and a workaround for
older compilers, which means that KASAN_EXTRA is now just as bad as
before and will lead to an instant stack overflow in a few extreme
cases.
This reverts parts of commit 3f181b4d86 ("lib/Kconfig.debug: disable
-Wframe-larger-than warnings with KASAN=y"). Two patches in linux-next
should be merged first to avoid introducing warnings in an allmodconfig
build:
3cd890dbe2 ("media: dvb-frontends: fix i2c access helpers for KASAN")
16c3ada89c ("media: r820t: fix r820t_write_reg for KASAN")
Do we really need to backport this?
I think we do: without this patch, enabling KASAN will lead to
unavoidable kernel stack overflow in certain device drivers when built
with gcc-7 or higher on linux-4.10+ or any version that contains a
backport of commit c5caf21ab0. Most people are probably still on
older compilers, but it will get worse over time as they upgrade their
distros.
The warnings we get on kernels older than this should all be for code
that uses dangerously large stack frames, though most of them do not
cause an actual stack overflow by themselves.The asan-stack option was
added in linux-4.0, and commit 3f181b4d86 ("lib/Kconfig.debug:
disable -Wframe-larger-than warnings with KASAN=y") effectively turned
off the warning for allmodconfig kernels, so I would like to see this
fix backported to any kernels later than 4.0.
I have done dozens of fixes for individual functions with stack frames
larger than 2048 bytes with asan-stack, and I plan to make sure that
all those fixes make it into the stable kernels as well (most are
already there).
Part of the complication here is that asan-stack (from 4.0) was
originally assumed to always require much larger stacks, but that
turned out to be a combination of multiple gcc bugs that we have now
worked around and fixed, but sanitize-address-use-after-scope (from
v4.10) has a much higher inherent stack usage and also suffers from at
least three other problems that we have analyzed but not yet fixed
upstream, each of them makes the stack usage more severe than it should
be.
Link: http://lkml.kernel.org/r/20171221134744.2295529-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Similarly to type mismatch checks, new GCC 8.x and Clang also changed for
ABI for returns_nonnull checks. While we can update our code to conform
the new ABI it's more reasonable to just remove it. Because it's just
dead code, we don't have any single user of returns_nonnull attribute in
the whole kernel.
And AFAIU the advantage that this attribute could bring would be mitigated
by -fno-delete-null-pointer-checks cflag that we use to build the kernel.
So it's unlikely we will have a lot of returns_nonnull attribute in
future.
So let's just remove the code, it has no use.
[aryabinin@virtuozzo.com: fix warning]
Link: http://lkml.kernel.org/r/20180122165711.11510-1-aryabinin@virtuozzo.com
Link: http://lkml.kernel.org/r/20180119152853.16806-2-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Sodagudi Prasad <psodagud@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some structure definitions that use macros trip the OPEN_BRACE test.
e.g. +struct bpf_map_def SEC("maps") control_map = {
Improve the test by using $balanced_parens instead of a .*
Miscellanea:
o Use $sline so any comments are ignored
o Correct the message output from declaration to definition
o Remove unnecessary parentheses
Link: http://lkml.kernel.org/r/db9b772999d1d2fbda3b9ee24bbca81a87837e13.1517543491.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using an open bracket after what seems to be a declaration can also be a
function definition and declaration argument line continuation so remove
the open bracket from the possible declaration/definition matching.
e.g.:
int foobar(int a;
int *b[]);
Link: http://lkml.kernel.org/r/1515704479.9619.171.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Greg KH doesn't like this test so exclude the staging directory from the
implied --strict only test unless --strict is actually used on the
command-line.
Link: http://lkml.kernel.org/r/1515704034.9619.165.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
DEVICE_ATTR is a declaration macro that has a few alternate and
preferred forms like DEVICE_ATTR_RW, DEVICE_ATTR_RO, and DEVICE_ATTR.
As well, many uses of DEVICE_ATTR could use the preferred forms when the
show or store functions are also named in a regular form.
Suggest the preferred forms when appropriate.
Also emit a permissions warning if the the permissions are not the
typical 0644, 0444, or 0200.
Link: http://lkml.kernel.org/r/725864f363d91d1e1e6894a39fb57662eabd6d65.1513803306.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Given this patch context,
+#define EFI_ST_DISK_IMG { \
+ 0x00000240, "\xbe\x5b\x7c\xac\x22\xc0\x74\x0b" /* .[|.".t. */ \
+ }
the current code misreports a quoted string line continuation defect as
there is a single quote in comment.
The 'raw' line should not be tested for quote count, the comment
substituted line should be instead.
Link: http://lkml.kernel.org/r/13f2735df10c33ca846e26f42f5cce6618157200.1513698599.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
module_param and create_proc uses with a permissions use of a single 0 are
"special" and should not emit any warning.
module_param uses with permission 0 are not visible in sysfs
create_proc uses with permission 0 use a default permission
Link: http://lkml.kernel.org/r/b6583611bb529ea6f6d43786827fddbabbab0a71.1513190059.git.joe@perches.com
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow lines with URL to exceed the 80 char limit for improved interaction
in adaption to ongoing but undocumented practice.
$ git grep -E '://\S{77}.*' -- '*.[ch]'
As per RFC3986 [1], the URL format allows for alphanum, +, - and .
characters in the scheme before the separator :// as long as it starts
with a letter (e.g. https, git, f.-+).
Recognition of URIs without more context information is prone to false
positives and thus currently left out of the heuristics.
$rawline is used in the check as comments are removed from $line.
[1] https://tools.ietf.org/html/rfc3986#section-3.1
Link: http://lkml.kernel.org/r/1511355432.12667.15.camel@elementarea.net
Signed-off-by: Andreas Brauchli <andreas.brauchli@sensirion.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
clang's AddressSanitizer implementation adds redzones on either side of
alloca()ed buffers. These redzones are 32-byte aligned and at least 32
bytes long.
__asan_alloca_poison() is passed the size and address of the allocated
buffer, *excluding* the redzones on either side. The left redzone will
always be to the immediate left of this buffer; but AddressSanitizer may
need to add padding between the end of the buffer and the right redzone.
If there are any 8-byte chunks inside this padding, we should poison
those too.
__asan_allocas_unpoison() is just passed the top and bottom of the dynamic
stack area, so unpoisoning is simpler.
Link: http://lkml.kernel.org/r/20171204191735.132544-4-paullawrence@google.com
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
LLVM doesn't understand GCC-style paramters ("--param asan-foo=bar"), thus
we currently we don't use inline/globals/stack instrumentation when
building the kernel with clang.
Add support for LLVM-style parameters ("-mllvm -asan-foo=bar") to enable
all KASAN features.
Link: http://lkml.kernel.org/r/20171204191735.132544-3-paullawrence@google.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With KASAN enabled the kernel has two different memset() functions, one
with KASAN checks (memset) and one without (__memset). KASAN uses some
macro tricks to use the proper version where required. For example
memset() calls in mm/slub.c are without KASAN checks, since they operate
on poisoned slab object metadata.
The issue is that clang emits memset() calls even when there is no
memset() in the source code. They get linked with improper memset()
implementation and the kernel fails to boot due to a huge amount of KASAN
reports during early boot stages.
The solution is to add -fno-builtin flag for files with KASAN_SANITIZE :=
n marker.
Link: http://lkml.kernel.org/r/8ffecfffe04088c52c42b92739c2bd8a0bcb3f5e.1516384594.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
GCC 8 changed the order of some fields and is very picky about ordering
in static initializers, so instead just move to dynamic initializers,
and drop the redundant already-zero field assignments.
Suggested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Kees Cook <keescook@chromium.org>
