Commit Graph

4344 Commits

Author SHA1 Message Date
Masahiro Yamada
1903c51190 kconfig: tests: add basic choice tests
The calculation of 'choice' is a bit complicated part in Kconfig.

The behavior of 'y' choice is intuitive.  If choice values are tristate,
the choice can be 'm' where each value can be enabled independently.
Also, if a choice is marked as 'optional', the whole choice can be
invisible.

Test basic functionality of choice.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
2018-03-26 02:04:02 +09:00
Masahiro Yamada
022a4bf6b5 kconfig: tests: add framework for Kconfig unit testing
Many parts in Kconfig are so cryptic and need refactoring.  However,
its complexity prevents us from moving forward.  There are several
naive corner cases where it is difficult to notice breakage.  If
those are covered by unit tests, we will be able to touch the code
with more confidence.

Here is a simple test framework based on pytest.  The conftest.py
provides a fixture useful to run commands such as 'oldaskconfig' etc.
and to compare the resulted .config, stdout, stderr with expectations.

How to add test cases?
----------------------

For each test case, you should create a subdirectory under
scripts/kconfig/tests/ (so test cases are separated from each other).
Every test case directory should contain the following files:

 - __init__.py: describes test functions
 - Kconfig: the top level Kconfig file for the test

To do a useful job, test cases generally need additional data like
input .config and information about expected results.

How to run tests?
-----------------

You need python3 and pytest.  Then, run "make testconfig".  O= option
is supported.  If V=1 is given, detailed logs captured during tests
are displayed.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
2018-03-26 02:04:01 +09:00
Ulf Magnusson
2a61625835 kconfig: remove redundant streamline_config.pl prerequisite
The local{yes,mod}config targets currently have streamline_config.pl as
a prerequisite. This is redundant, because streamline_config.pl is a
checked-in file with no prerequisites.

Remove the prerequisite and reference streamline_config.pl directly in
the recipe of the rule instead.

Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-03-26 02:04:01 +09:00
Masahiro Yamada
911a91c39c kconfig: rename silentoldconfig to syncconfig
As commit cedd55d49d ("kconfig: Remove silentoldconfig from help
and docs; fix kconfig/conf's help") mentioned, 'silentoldconfig' is a
historical misnomer.  That commit removed it from help and docs since
it is an internal interface.  If so, it should be allowed to rename
it to something more intuitive.  'syncconfig' is the one I came up
with because it updates the .config if necessary, then synchronize
include/generated/autoconf.h and include/config/* with it.

You should not manually invoke 'silentoldcofig'.  Display warning if
used in case existing scripts are doing wrong.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
2018-03-26 02:04:00 +09:00
Masahiro Yamada
81d2bc2273 kconfig: invoke oldconfig instead of silentoldconfig from local*config
The purpose of local{yes,mod}config is to arrange the .config file
based on actually loaded modules.  It is unnecessary to update
include/generated/autoconf.h and include/config/* stuff here.
They will be updated as needed during the build.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
2018-03-26 02:04:00 +09:00
Masahiro Yamada
2aad9b8962 kconfig: hide irrelevant sub-menus for oldconfig
Historically, "make oldconfig" has changed its behavior several times,
quieter or louder.  (I attached the history below.)  Currently, it is
not as quiet as it should be.  This commit addresses it.

  Test Case
  ---------

---------------------------(Kconfig)----------------------------
menu "menu"

config FOO
        bool "foo"

menu "sub menu"

config BAR
        bool "bar"

endmenu

endmenu

menu "sibling menu"

config BAZ
        bool "baz"

endmenu
----------------------------------------------------------------

---------------------------(.config)----------------------------
CONFIG_BAR=y
CONFIG_BAZ=y
----------------------------------------------------------------

With the Kconfig and .config above, "make silentoldconfig" and
"make oldconfig" work differently, like follows:

  $ make silentoldconfig
  scripts/kconfig/conf  --silentoldconfig Kconfig
  *
  * Restart config...
  *
  *
  * menu
  *
  foo (FOO) [N/y/?] (NEW) y
  #
  # configuration written to .config
  #

  $ make oldconfig
  scripts/kconfig/conf  --oldconfig Kconfig
  *
  * Restart config...
  *
  *
  * menu
  *
  foo (FOO) [N/y/?] (NEW) y
  *
  * sub menu
  *
  bar (BAR) [Y/n/?] y
  #
  # configuration written to .config
  #

Both hide "sibling node" since it is irrelevant.  The difference is
that silentoldconfig hides "sub menu" whereas oldconfig does not.
The behavior of silentoldconfig is preferred since the "sub menu"
does not contain any new symbol.

The root cause is in conf().  There are three input modes that can
call conf(); oldaskconfig, oldconfig, and silentoldconfig.

Everytime conf() encounters a menu entry, it calls check_conf() to
check if it contains new symbols.  If no new symbol is found, the
menu is just skipped.

Currently, this happens only when input_mode == silentoldconfig.
The oldaskconfig enters into the check_conf() loop as silentoldconfig,
so oldaskconfig works likewise for the second loop or later, but it
never happens for oldconfig.  So, irrelevant sub-menus are shown for
oldconfig.

Change the test condition to "input_mode != oldaskconfig".  This is
false only for the first loop of oldaskconfig; it must ask the user
all symbols, so no need to call check_conf().

  History of oldconfig
  --------------------

[0] Originally, "make oldconfig" was as loud as "make config"  (It
    showed the entire .config file)

[1] Commit cd9140e1e7 ("kconfig: make oldconfig is now less chatty")
    made oldconfig quieter, but it was still less quieter than
    silentoldconfig.  (oldconfig did not hide sub-menus)

[2] Commit 204c96f609 ("kconfig: fix silentoldconfig") changed
    the input_mode of oldconfig to "ask_silent" from "ask_new".
    So, oldconfig really became as quiet as silentoldconfig.
    (oldconfig hided irrelevant sub-menus)

[3] Commit 4062f1a4c0 ("kconfig: use long options in conf") made
    oldconfig as loud as [0] due to misconversion.

[4] Commit 1482834971 ("kconfig: fix make oldconfig") addressed
    the misconversion of [3], but it made oldconfig quieter only to
    the same level as [1], not [2].

This commit is restoring the behavior of [2].

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
2018-03-26 02:03:59 +09:00
Masahiro Yamada
99f0b6578b kconfig: remove redundant input_mode test for check_conf() loop
check_conf() never increments conf_cnt for listnewconfig, so conf_cnt
is always zero.

In other words, conf_cnt is not zero, "input_mode != listnewconfig"
is met.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
2018-03-26 02:03:59 +09:00
Masahiro Yamada
4bb3a5b085 kconfig: remove unneeded input_mode test in conf()
conf() is never called for listnewconfig / olddefconfig.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
2018-03-26 02:03:59 +09:00
Masahiro Yamada
59a80b5e89 kconfig: do not call check_conf() for olddefconfig
check_conf() traverses the menu tree, but it is completely no-op for
olddefconfig because the following if-else block does nothing.

    if (input_mode == listnewconfig) {
            ...
    } else if (input_mode != olddefconfig) {
            ...
    }

As the help message says, olddefconfig automatically sets new symbols
to their default value.  There is no room for manual intervention.
So, calling check_conf() for olddefconfig is odd in the first place.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
2018-03-26 02:03:58 +09:00
Ulf Magnusson
f467c5640c kconfig: only write '# CONFIG_FOO is not set' for visible symbols
=== 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>
2018-03-26 02:03:58 +09:00
Eugeniu Rosca
d9119b5925 kconfig: Print reverse dependencies in groups
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>
2018-03-26 02:03:58 +09:00
Masahiro Yamada
9a47ceec54 kconfig: clean-up reverse dependency help implementation
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>
2018-03-26 02:03:57 +09:00
Ulf Magnusson
84af7a6194 checkpatch: kconfig: prefer 'help' over '---help---'
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>
2018-03-26 02:03:57 +09:00
Ulf Magnusson
678ae162dd checkpatch: kconfig: check help texts for menuconfig and choice
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>
2018-03-26 02:03:56 +09:00
Ulf Magnusson
86adf1a07e checkpatch: kconfig: recognize more prompts when checking help texts
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>
2018-03-26 02:03:56 +09:00
James Hogan
55fe6da9ef kbuild: Handle builtin dtb file names containing hyphens
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>
2018-03-09 01:14:38 +09:00
Matteo Croce
61fc470814 scripts/bloat-o-meter: fix typos in help
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>
2018-03-09 01:12:31 +09:00
Rasmus Villemoes
638e69cf22 fixdep: do not ignore kconfig.h
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>
2018-03-05 23:48:29 +09:00
Rasmus Villemoes
5b8ad96d1a fixdep: remove some false CONFIG_ matches
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>
2018-03-05 23:48:25 +09:00
Rasmus Villemoes
14a596a7e6 fixdep: remove stale references to uml-config.h
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>
2018-03-05 23:48:21 +09:00
Linus Torvalds
0eb3412a68 Kbuild fixes for v4.16
- 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
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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
2018-03-03 10:37:01 -08:00
Masahiro Yamada
5ae6fcc4bb kconfig: fix line number in recursive inclusion error message
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>
2018-03-03 00:44:47 +09:00
Dafna Hirschfeld
a11761c2dd Coccinelle: memdup: Fix typo in warning messages
Replace 'kmemdep' with 'kmemdup' in warning messages.

Signed-off-by: Dafna Hirschfeld <dafna3@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Acked-by: Nicolas Palix <nicolas.palix@imag.fr>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-03-03 00:41:24 +09:00
Arvind Prasanna
1a90ce36c6 kconfig: Update ncurses package names for menuconfig
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>
2018-03-02 09:20:57 +09:00
Cao jin
cbf7a90e30 kbuild/kallsyms: trivial typo fix
Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-03-02 09:20:56 +09:00
Cao jin
a7b151fffb kbuild: drop superfluous GCC_PLUGINS_CFLAGS assignment
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>
2018-03-02 09:20:56 +09:00
Masahiro Yamada
bf0bbdcf10 kconfig: Don't leak choice names during parsing
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>
2018-03-02 09:20:55 +09:00
Masahiro Yamada
f4bc1eefc1 kconfig: set SYMBOL_AUTO to the symbol marked with defconfig_list
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>
2018-03-02 09:20:44 +09:00
Masahiro Yamada
cd81fc82b9 kconfig: add xstrdup() helper
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>
2018-03-02 00:26:47 +09:00
Peter Zijlstra
d5028ba8ee objtool, retpolines: Integrate objtool with retpoline support more closely
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>
2018-02-21 16:54:32 +01:00
Peter Zijlstra
ca41b97ed9 objtool: Add module specific retpoline rules
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>
2018-02-21 09:05:05 +01:00
Peter Zijlstra
b5bc2231b8 objtool: Add retpoline validation
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>
2018-02-21 09:05:04 +01:00
Linus Torvalds
9a61df9e5f Kbuild updates for v4.16 (2nd)
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
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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
  ...
2018-02-09 19:32:41 -08:00
Masahiro Yamada
523ca58b7d kconfig: remove const qualifier from sym_expand_string_value()
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>
2018-02-10 11:31:49 +09:00
Masahiro Yamada
d717f24d8c kconfig: add xrealloc() helper
We already have xmalloc(), xcalloc().  Add xrealloc() as well
to save tedious error handling.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-02-10 11:26:04 +09:00
Linus Torvalds
4ed8244ef8 - update includes for gcc 8 (Valdis Kletnieks)
- update initializers for gcc 8
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Merge tag 'gcc-plugins-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull gcc plugins updates from Kees Cook:

 - update includes for gcc 8 (Valdis Kletnieks)

 - update initializers for gcc 8

* tag 'gcc-plugins-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  gcc-plugins: Use dynamic initializers
  gcc-plugins: Add include required by GCC release 8
2018-02-08 14:37:32 -08:00
Masahiro Yamada
9e3e10c725 kconfig: send error messages to stderr
These messages should be directed to stderr.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
2018-02-09 04:10:10 +09:00
Masahiro Yamada
f3ff6fb5db kconfig: echo stdin to stdout if either is redirected
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>
2018-02-09 04:10:10 +09:00
Masahiro Yamada
d2a04648a5 kconfig: remove check_stdin()
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>
2018-02-09 04:10:10 +09:00
Masahiro Yamada
cd58a91def kconfig: remove 'config*' pattern from .gitignnore
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>
2018-02-09 04:10:09 +09:00
Masahiro Yamada
4f208f3921 kconfig: show '?' prompt even if no help text is available
'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>
2018-02-09 04:10:09 +09:00
Masahiro Yamada
cb67ab2cd2 kconfig: do not write choice values when their dependency becomes n
"# 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>
2018-02-09 04:08:05 +09:00
Linus Torvalds
581e400ff9 Modules updates for v4.16
Summary of modules changes for the 4.16 merge window:
 
 - Minor code cleanups and MAINTAINERS update
 
 Signed-off-by: Jessica Yu <jeyu@kernel.org>
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Merge tag 'modules-for-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

Pull modules updates from Jessica Yu:
 "Minor code cleanups and MAINTAINERS update"

* tag 'modules-for-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  modpost: Remove trailing semicolon
  ftrace/module: Move ftrace_release_mod() to ddebug_cleanup label
  MAINTAINERS: Remove from module & paravirt maintenance
2018-02-07 14:29:34 -08:00
Julia Lawall
a2b0fe7435 coccinelle: deref_null: avoid useless computation
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>
2018-02-08 00:16:12 +09:00
Julia Lawall
e856f3a7d7 coccinelle: devm_free: reduce false positives
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>
2018-02-07 23:53:09 +09:00
Arnd Bergmann
e7c52b84fb kasan: rework Kconfig settings
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>
2018-02-06 18:32:47 -08:00
Andrey Ryabinin
bac7a1fff7 lib/ubsan: remove returns-nonnull-attribute checks
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>
2018-02-06 18:32:46 -08:00
Joe Perches
2d453e3b41 checkpatch: improve OPEN_BRACE test
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>
2018-02-06 18:32:45 -08:00
Joe Perches
bd49111f7d checkpatch: avoid some false positives for TABSTOP declaration test
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>
2018-02-06 18:32:45 -08:00
Joe Perches
a032aa4c4a checkpatch: exclude drivers/staging from if with unnecessary parentheses test
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>
2018-02-06 18:32:45 -08:00