Commit Graph

918 Commits

Author SHA1 Message Date
Linus Torvalds
14cd0bd049 Kconfig updates for v5.6
- add 'yes2modconfig' and 'mod2yesconfig' targets
 
  - sanitize help text
 
  - various code cleanups
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Merge tag 'kconfig-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kconfig updates from Masahiro Yamada:

 - add 'yes2modconfig' and 'mod2yesconfig' targets (useful mainly for
   turning syzbot configs into more modular ones as a step to minimizing
   the result)

 - sanitize help text

 - various code cleanups

* tag 'kconfig-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: fix documentation typos
  kconfig: fix an "implicit declaration of function" warning
  kconfig: fix nesting of symbol help text
  kconfig: distinguish between dependencies and visibility in help text
  kconfig: list all definitions of a symbol in help text
  kconfig: Add yes2modconfig and mod2yesconfig targets.
  kconfig: use $(PERL) in Makefile
  kconfig: fix too deep indentation in Makefile
  kconfig: localmodconfig: fix indentation for closing brace
  kconfig: localmodconfig: remove unused $config
  kconfig: squash prop_alloc() into menu_add_prop()
  kconfig: remove sym from struct property
  kconfig: remove 'prompt' argument from menu_add_prop()
  kconfig: move prompt handling to menu_add_prompt() from menu_add_prop()
  kconfig: remove 'prompt' symbol
  kconfig: drop T_WORD from the RHS of 'prompt' symbol
  kconfig: use parent->dep as the parentdep of 'menu'
  kconfig: remove the rootmenu check in menu_add_prop()
2020-02-01 10:25:55 -08:00
Bartosz Golaszewski
ba82f52e22 kconfig: fix an "implicit declaration of function" warning
strncasecmp() & strcasecmp() functions are declared in strings.h, not
string.h. On most environments the former is implicitly included by
the latter but on some setups, building menuconfig results in the
following warning:

  HOSTCC  scripts/kconfig/mconf.o
scripts/kconfig/mconf.c: In function ‘search_conf’:
scripts/kconfig/mconf.c:423:6: warning: implicit declaration of function ‘strncasecmp’ [-Wimplicit-function-declaration]
  if (strncasecmp(dialog_input_result, CONFIG_, strlen(CONFIG_)) == 0)
      ^~~~~~~~~~~
scripts/kconfig/mconf.c: In function ‘main’:
scripts/kconfig/mconf.c:1021:8: warning: implicit declaration of function ‘strcasecmp’ [-Wimplicit-function-declaration]
   if (!strcasecmp(mode, "single_menu"))
        ^~~~~~~~~~

Fix it by explicitly including strings.h.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-10 02:44:54 +09:00
Thomas Hebb
a960968604 kconfig: fix nesting of symbol help text
When we generate the help text of a symbol (e.g. when a user presses '?'
in menuconfig), we do two things:

 1. We iterate through every prompt that belongs to that symbol,
    printing its text and its location in the menu tree.
 2. We print symbol-wide information that's not linked to a particular
    prompt, such as what it selects/is selected by and what it
    implies/is implied by.

Each prompt we print for 1 starts with a line that's not indented
indicating where the prompt is defined, then continues with indented
lines that describe properties of that particular definition.

Once we get to 2, however, we print all the global data indented as
well! Visually, this makes it look like the symbol-wide data is
associated with the last prompt we happened to print rather than
the symbol as a whole.

Fix this by removing the indentation for symbol-wide information.

Before:

  Symbol: CPU_FREQ [=n]
  Type  : bool
  Defined at drivers/cpufreq/Kconfig:4
    Prompt: CPU Frequency scaling
    Location:
      -> CPU Power Management
        -> CPU Frequency scaling
    Selects: SRCU [=n]
    Selected by [n]:
    - ARCH_SA1100 [=n] && <choice>

After:

  Symbol: CPU_FREQ [=n]
  Type  : bool
  Defined at drivers/cpufreq/Kconfig:4
    Prompt: CPU Frequency scaling
    Location:
      -> CPU Power Management
        -> CPU Frequency scaling
  Selects: SRCU [=n]
  Selected by [n]:
    - ARCH_SA1100 [=n] && <choice>

Signed-off-by: Thomas Hebb <tommyhebb@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-07 02:18:45 +09:00
Thomas Hebb
3460d0bc25 kconfig: distinguish between dependencies and visibility in help text
Kconfig makes a distinction between dependencies (defined by "depends
on" expressions and enclosing "if" blocks) and visibility (which
includes all dependencies, but also includes inline "if" expressions of
individual properties as well as, for prompts, "visible if" expressions
of enclosing menus).

Before commit bcdedcc1af ("menuconfig: print more info for symbol
without prompts"), the "Depends on" lines of a symbol's help text
indicated the visibility of the prompt property they appeared under.
After bcdedcc1af, there was always only a single "Depends on" line,
which indicated the visibility of the first P_SYMBOL property of the
symbol. Since P_SYMBOLs never have inline if expressions, this was in
effect the same as the dependencies of the menu item that the P_SYMBOL
was attached to.

Neither of these situations accurately conveyed the dependencies of a
symbol--the first because it was actually the visibility, and the second
because it only showed the dependencies from a single definition.

With this series, we are back to printing separate dependencies for each
definition, but we print the actual dependencies (rather than the
visibility) in the "Depends on" line. However, it can still be useful to
know the visibility of a prompt, so this patch adds a "Visible if" line
that shows the visibility only if the visibility is different from the
dependencies (which it isn't for most prompts in Linux).

Before:

  Symbol: THUMB2_KERNEL [=n]
  Type  : bool
  Defined at arch/arm/Kconfig:1417
    Prompt: Compile the kernel in Thumb-2 mode
    Depends on: (CPU_V7 [=y] || CPU_V7M [=n]) && !CPU_V6 [=n] && !CPU_V6K [=n]
    Location:
      -> Kernel Features
    Selects: ARM_UNWIND [=n]

After:

   Symbol: THUMB2_KERNEL [=n]
   Type  : bool
   Defined at arch/arm/Kconfig:1417
     Prompt: Compile the kernel in Thumb-2 mode
     Depends on: (CPU_V7 [=y] || CPU_V7M [=n]) && !CPU_V6 [=n] && !CPU_V6K [=n]
     Visible if: (CPU_V7 [=y] || CPU_V7M [=n]) && !CPU_V6 [=n] && !CPU_V6K [=n] && !CPU_THUMBONLY [=n]
     Location:
       -> Kernel Features
     Selects: ARM_UNWIND [=n]

Signed-off-by: Thomas Hebb <tommyhebb@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-07 02:18:45 +09:00
Thomas Hebb
edda15f219 kconfig: list all definitions of a symbol in help text
In Kconfig, each symbol (representing a config option) can be defined in
multiple places. Each definition may or may not have a prompt, which
allows the option to be set via an interface like menuconfig. Each
definition has a set of dependencies, which determine whether its prompt
is visible and whether other pieces of the definition, like a default
value, take effect.

Historically, a symbol's help text (i.e. what's shown when a user
presses '?' in menuconfig) contained some symbol-wide information not
tied to any particular definition (e.g. what other symbols it selects)
as well as the location (file name and line number) and dependencies of
each prompt. Notably, the help text did not show the location or
dependencies of definitions without prompts.

Because this made it hard to reason about symbols that had no prompts,
commit bcdedcc1af ("menuconfig: print more info for symbol without
prompts") changed the help text so that, instead of containing the
location and dependencies of each prompt, it contained the location and
dependencies of the symbol's first definition, regardless of whether or
not that definition had a prompt.

For symbols with only one definition, that change makes sense. However,
it breaks down for symbols with multiple definitions: each definition
has its own set of dependencies (the `dep` field of `struct menu`), and
those dependencies are ORed together to get the symbol's dependency list
(the `dir_dep` field of `struct symbol`). By printing only the
dependencies of the first definition, the help text misleads users into
believing that an option is more narrowly-applicable than it actually
is.

For an extreme example of this, we can look at the SYS_TEXT_BASE symbol
in the Das U-Boot project (version 2019.10), which also uses Kconfig. (I
unfortunately could not find an illustrative example in Linux.) This
config option specifies the load address of the built binary and, as
such, is applicable to basically every configuration possible. And yet,
without this patch, its help text is as follows:

  Symbol: SYS_TEXT_BASE [=]
  Type  : hex
  Prompt: U-Boot base address
    Location:
      -> ARM architecture
  Prompt: Text Base
    Location:
      -> Boot images
    Defined at arch/arm/mach-aspeed/Kconfig:9
    Depends on: ARM [=n] && ARCH_ASPEED [=n]

The help text indicates that the option is applicable only for a
specific unselected architecture (aspeed), because that architecture's
promptless definition (which just sets a default value), happens to be
the first one seen. No definition or dependency information is printed
for either of the two prompts listed.

Because source locations and dependencies are fundamentally properties
of definitions and not of symbols, we should treat them as such. This
patch brings back the pre-bcdedcc1afd6 behavior for definitions with
prompts but also separately prints the location and dependencies of
those without prompts, solving the original problem in a different way.
With this change, our SYS_TEXT_BASE example becomes

   Symbol: SYS_TEXT_BASE [=]
   Type  : hex
   Defined at arch/arm/mach-stm32mp/Kconfig:83
     Prompt: U-Boot base address
     Depends on: ARM [=n] && ARCH_STM32MP [=n]
     Location:
       -> ARM architecture
   Defined at Kconfig:532
     Prompt: Text Base
     Depends on: !NIOS2 [=n] && !XTENSA [=n] && !EFI_APP [=n]
     Location:
       -> Boot images
   Defined at arch/arm/mach-aspeed/Kconfig:9
     Depends on: ARM [=n] && ARCH_ASPEED [=n]
   Defined  at arch/arm/mach-socfpga/Kconfig:25
     Depends on: ARM [=n] && ARCH_SOCFPGA [=n]
   <snip>
   Defined at board/sifive/fu540/Kconfig:15
     Depends on: RISCV [=n] && TARGET_SIFIVE_FU540 [=n]

which is a much more accurate representation.

Note that there is one notable difference between what gets printed for
prompts after this change and what got printed before bcdedcc1af: the
"Depends on" line now accurately represents the prompt's dependencies
instead of conflating those with the prompt's visibility (which can
include extra conditions). See the patch later in this series titled
"kconfig: distinguish between dependencies and visibility in help text"
for more details and better handling of that nuance.

Signed-off-by: Thomas Hebb <tommyhebb@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-07 02:18:45 +09:00
Tetsuo Handa
89b9060987 kconfig: Add yes2modconfig and mod2yesconfig targets.
Since kernel configs provided by syzbot are close to "make allyesconfig",
it takes long time to rebuild. This is especially waste of time when we
need to rebuild for many times (e.g. doing manual printk() inspection,
bisect operations).

We can save time if we can exclude modules which are irrelevant to each
problem. But "make localmodconfig" cannot exclude modules which are built
into vmlinux because /sbin/lsmod output is used as the source of modules.

Therefore, this patch adds "make yes2modconfig" which converts from =y
to =m if possible. After confirming that the interested problem is still
reproducible, we can try "make localmodconfig" (and/or manually tune
based on "Modules linked in:" line) in order to exclude modules which are
irrelevant to the interested problem. While we are at it, this patch also
adds "make mod2yesconfig" which converts from =m to =y in case someone
wants to convert from =m to =y after "make localmodconfig".

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-07 02:18:45 +09:00
Masahiro Yamada
c8138a57bb kconfig: use $(PERL) in Makefile
The top Makefile defines and exports the variable 'PERL'. Use it in
case somebody wants to specify a particular version of perl from the
command line.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-07 02:18:45 +09:00
Masahiro Yamada
1d1352373e kconfig: fix too deep indentation in Makefile
The indentation for if ... else ... fi is too deep. Fix it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-07 02:18:45 +09:00
Masahiro Yamada
68f0d62746 kconfig: localmodconfig: fix indentation for closing brace
This is the closing brace for the foreach loop. Fix the misleading
indentation.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-07 02:18:45 +09:00
Masahiro Yamada
5edcef8454 kconfig: localmodconfig: remove unused $config
This is unused since commit cdfc47950a ("kconfig: search for a config
to base the local(mod|yes)config on").

Having unused $config is confusing because $config is used as a local
variable in various sub-routines.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-07 02:18:44 +09:00
Masahiro Yamada
adf7c5bd06 kconfig: squash prop_alloc() into menu_add_prop()
prop_alloc() is only called from menu_add_prop(). Squash it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-07 02:18:44 +09:00
Masahiro Yamada
6397d96ba5 kconfig: remove sym from struct property
struct property can reference to the symbol that it is associated with
by prop->menu->sym.

Fix up the one usage of prop->sym, and remove sym from struct property.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-07 02:18:44 +09:00
Masahiro Yamada
2ffeef615b kconfig: remove 'prompt' argument from menu_add_prop()
This function no longer uses the 'prompt' argument.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-07 02:18:44 +09:00
Masahiro Yamada
024352ff8d kconfig: move prompt handling to menu_add_prompt() from menu_add_prop()
menu_add_prompt() is the only function that calls menu_add_prop() with
non-NULL prompt.

So, the code inside the if-conditional block of menu_add_prop() can be
moved to menu_add_prompt().

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-07 02:18:44 +09:00
Masahiro Yamada
1be6e79138 kconfig: remove 'prompt' symbol
Now that 'prompt' is only reduced from T_WORD_QUOTE without any action,
use T_WORD_QUOTE directly.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-07 02:18:44 +09:00
Masahiro Yamada
801b27db46 kconfig: drop T_WORD from the RHS of 'prompt' symbol
Commit 8636a1f967 ("treewide: surround Kconfig file paths with double
quotes") killed use-cases to reduce an unquoted string into the 'prompt'
symbol.

Kconfig still allows to use an unquoted string in the context of menu,
source, or prompt.

So, you can omit quoting if the prompt is a single word:

    bool foo

..., but I do not think this is so useful.

Let's require quoting:

    bool "foo"

All the Kconfig files in the kernel are written in this way.

Remove the T_WORD from the right-hand side of the symbol 'prompt'.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-07 02:18:44 +09:00
Masahiro Yamada
de026ca915 kconfig: use parent->dep as the parentdep of 'menu'
In menu_finalize(), the dependency of a menu entry is propagated
downwards.

For the 'menu', parent->dep and parent->prompt->visible.expr have
the same expression. Both accumulate the 'depends on' of itself and
upper menu entries.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-07 02:18:44 +09:00
Masahiro Yamada
f64048a20b kconfig: remove the rootmenu check in menu_add_prop()
This reverts commit ba6ff60d5e ("kconfig: don't emit warning upon
rootmenu's prompt redefinition").

At that time, rootmenu.prompt was always set first, then it was set
again if a "mainmenu" statement was specified in the Kconfig file.

This is no longer the case since commit 0724a7c32a ("kconfig: Don't
leak main menus during parsing"). Remove the unneeded check.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-07 02:18:44 +09:00
Masahiro Yamada
8b41fc4454 kbuild: create modules.builtin without Makefile.modbuiltin or tristate.conf
Commit bc081dd6e9 ("kbuild: generate modules.builtin") added
infrastructure to generate modules.builtin, the list of all
builtin modules.

Basically, it works like this:

  - Kconfig generates include/config/tristate.conf, the list of
    tristate CONFIG options with a value in a capital letter.

  - scripts/Makefile.modbuiltin makes Kbuild descend into
    directories to collect the information of builtin modules.

I am not a big fan of it because Kbuild ends up with traversing
the source tree twice.

I am not sure how perfectly it should work, but this approach cannot
avoid false positives; even if the relevant CONFIG option is tristate,
some Makefiles forces obj-m to obj-y.

Some examples are:

  arch/powerpc/platforms/powermac/Makefile:
    obj-$(CONFIG_NVRAM:m=y)         += nvram.o

  net/ipv6/Makefile:
    obj-$(subst m,y,$(CONFIG_IPV6)) += inet6_hashtables.o

  net/netlabel/Makefile:
    obj-$(subst m,y,$(CONFIG_IPV6)) += netlabel_calipso.o

Nobody has complained about (or noticed) it, so it is probably fine to
have false positives in modules.builtin.

This commit simplifies the implementation. Let's exploit the fact
that every module has MODULE_LICENSE(). (modpost shows a warning if
MODULE_LICENSE is missing. If so, 0-day bot would already have blocked
such a module.)

I added MODULE_FILE to <linux/module.h>. When the code is being compiled
as builtin, it will be filled with the file path of the module, and
collected into modules.builtin.info. Then, scripts/link-vmlinux.sh
extracts the list of builtin modules out of it.

This new approach fixes the false-positives above, but adds another
type of false-positives; non-modular code may have MODULE_LICENSE()
by mistake. This is not a big deal, it is just the code is always
orphan. We can clean it up if we like. You can see cleanup examples by:

  $ git log --grep='make.* explicitly non-modular'

To sum up, this commits deletes lots of code, but still produces almost
equivalent results. Please note it does not increase the vmlinux size at
all. As you can see in include/asm-generic/vmlinux.lds.h, the .modinfo
section is discarded in the link stage.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-07 02:18:39 +09:00
Thomas Hebb
272a721030 kconfig: don't crash on NULL expressions in expr_eq()
NULL expressions are taken to always be true, as implemented by the
expr_is_yes() macro and by several other functions in expr.c. As such,
they ought to be valid inputs to expr_eq(), which compares two
expressions.

Signed-off-by: Thomas Hebb <tommyhebb@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2019-12-17 19:21:07 +09:00
Alyssa Ross
46b2afa689 kconfig: be more helpful if pkg-config is missing
If ncurses is installed, but at a non-default location, the previous
error message was not helpful in resolving the situation.  Now it will
suggest that pkg-config might need to be installed in addition to
ncurses.

Signed-off-by: Alyssa Ross <hi@alyssa.is>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-11-11 20:10:01 +09:00
Laura Abbott
5d8b42aa7c kconfig: Add option to get the full help text with listnewconfig
make listnewconfig will list the individual options that need to be set.
This is useful but there's no easy way to get the help text associated
with the options at the same time. Introduce a new targe
'make helpnewconfig' which lists the full help text of all the
new options as well. This makes it easier to automatically generate
changes that are easy for humans to review. This command also adds
markers between each option for easier parsing.

Signed-off-by: Laura Abbott <labbott@redhat.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-11-11 20:10:01 +09:00
Geert Uytterhoeven
a64c0440dd kbuild: Wrap long "make help" text lines
Some "make help" text lines extend beyond 80 characters.
Wrap them before an opening parenthesis, or before 80 characters.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-11-11 20:10:01 +09:00
Masahiro Yamada
521b29b6ff kconfig: split util.c out of parser.y
util.c exists both in scripts/kconfig/ and scripts/kconfig/lxdialog.

Prior to commit 54b8ae66ae ("kbuild: change *FLAGS_<basetarget>.o
to take the path relative to $(obj)"), Kbuild could not pass different
flags to source files with the same basename. Now that this issue
was solved, you can split util.c out of parser.y and compile them
independently of each other.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-11-11 20:07:03 +09:00
Guillaume Tucker
60bef52c7a merge_config.sh: ignore unwanted grep errors
The merge_config.sh script verifies that all the config options have
their expected value in the resulting file and prints any issues as
warnings.  These checks aren't intended to be treated as errors given
the current implementation.  However, since "set -e" was added, if the
grep command to look for a config option does not find it the script
will then abort prematurely.

Handle the case where the grep exit status is non-zero by setting
ACTUAL_VAL to an empty string to restore previous functionality.

Fixes: cdfca82157 ("merge_config.sh: Check error codes from make")
Signed-off-by: Guillaume Tucker <guillaume.tucker@collabora.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-09-04 23:12:50 +09:00
Masahiro Yamada
54b8ae66ae kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj)
Kbuild provides per-file compiler flag addition/removal:

  CFLAGS_<basetarget>.o
  CFLAGS_REMOVE_<basetarget>.o
  AFLAGS_<basetarget>.o
  AFLAGS_REMOVE_<basetarget>.o
  CPPFLAGS_<basetarget>.lds
  HOSTCFLAGS_<basetarget>.o
  HOSTCXXFLAGS_<basetarget>.o

The <basetarget> is the filename of the target with its directory and
suffix stripped.

This syntax comes into a trouble when two files with the same basename
appear in one Makefile, for example:

  obj-y += foo.o
  obj-y += dir/foo.o
  CFLAGS_foo.o := <some-flags>

Here, the <some-flags> applies to both foo.o and dir/foo.o

The real world problem is:

  scripts/kconfig/util.c
  scripts/kconfig/lxdialog/util.c

Both files are compiled into scripts/kconfig/mconf, but only the
latter should be given with the ncurses flags.

It is more sensible to use the relative path to the Makefile, like this:

  obj-y += foo.o
  CFLAGS_foo.o := <some-flags>
  obj-y += dir/foo.o
  CFLAGS_dir/foo.o := <other-flags>

At first, I attempted to replace $(basetarget) with $*. The $* variable
is replaced with the stem ('%') part in a pattern rule. This works with
most of cases, but does not for explicit rules.

For example, arch/ia64/lib/Makefile reuses rule_as_o_S in its own
explicit rules, so $* will be empty, resulting in ignoring the per-file
AFLAGS.

I introduced a new variable, target-stem, which can be used also from
explicit rules.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Marc Zyngier <maz@kernel.org>
2019-09-04 23:12:50 +09:00
Masahiro Yamada
1634f2bfdb kbuild: remove clean-dirs syntax
The only the difference between clean-files and clean-dirs is the -r
option passed to the 'rm' command.

You can always pass -r, and then remove the clean-dirs syntax.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-08-29 23:54:29 +09:00
Mark Brown
cdfca82157 merge_config.sh: Check error codes from make
When we execute make after merging the configurations we ignore any
errors it produces causing whatever is running merge_config.sh to be
unaware of any failures.  This issue was noticed by Guillaume Tucker
while looking at problems with testing of clang only builds in KernelCI
which caused Kbuild to be unable to find a working host compiler.

This implementation was suggested by Yamada-san.

Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reported-by: Guillaume Tucker <guillaume.tucker@collabora.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-08-22 01:14:11 +09:00
M. Vefa Bicakci
0c5b6c28ed kconfig: Clear "written" flag to avoid data loss
Prior to this commit, starting nconfig, xconfig or gconfig, and saving
the .config file more than once caused data loss, where a .config file
that contained only comments would be written to disk starting from the
second save operation.

This bug manifests itself because the SYMBOL_WRITTEN flag is never
cleared after the first call to conf_write, and subsequent calls to
conf_write then skip all of the configuration symbols due to the
SYMBOL_WRITTEN flag being set.

This commit resolves this issue by clearing the SYMBOL_WRITTEN flag
from all symbols before conf_write returns.

Fixes: 8e2442a5f8 ("kconfig: fix missing choice values in auto.conf")
Cc: linux-stable <stable@vger.kernel.org> # 4.19+
Signed-off-by: M. Vefa Bicakci <m.v.b@runbox.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-08-04 12:44:15 +09:00
Masahiro Yamada
8e2442a5f8 kconfig: fix missing choice values in auto.conf
Since commit 00c864f890 ("kconfig: allow all config targets to write
auto.conf if missing"), Kconfig creates include/config/auto.conf in the
defconfig stage when it is missing.

Joonas Kylmälä reported incorrect auto.conf generation under some
circumstances.

To reproduce it, apply the following diff:

|  --- a/arch/arm/configs/imx_v6_v7_defconfig
|  +++ b/arch/arm/configs/imx_v6_v7_defconfig
|  @@ -345,14 +345,7 @@ CONFIG_USB_CONFIGFS_F_MIDI=y
|   CONFIG_USB_CONFIGFS_F_HID=y
|   CONFIG_USB_CONFIGFS_F_UVC=y
|   CONFIG_USB_CONFIGFS_F_PRINTER=y
|  -CONFIG_USB_ZERO=m
|  -CONFIG_USB_AUDIO=m
|  -CONFIG_USB_ETH=m
|  -CONFIG_USB_G_NCM=m
|  -CONFIG_USB_GADGETFS=m
|  -CONFIG_USB_FUNCTIONFS=m
|  -CONFIG_USB_MASS_STORAGE=m
|  -CONFIG_USB_G_SERIAL=m
|  +CONFIG_USB_FUNCTIONFS=y
|   CONFIG_MMC=y
|   CONFIG_MMC_SDHCI=y
|   CONFIG_MMC_SDHCI_PLTFM=y

And then, run:

$ make ARCH=arm mrproper imx_v6_v7_defconfig

You will see CONFIG_USB_FUNCTIONFS=y is correctly contained in the
.config, but not in the auto.conf.

Please note drivers/usb/gadget/legacy/Kconfig is included from a choice
block in drivers/usb/gadget/Kconfig. So USB_FUNCTIONFS is a choice value.

This is probably a similar situation described in commit beaaddb625
("kconfig: tests: test defconfig when two choices interact").

When sym_calc_choice() is called, the choice symbol forgets the
SYMBOL_DEF_USER unless all of its choice values are explicitly set by
the user.

The choice symbol is given just one chance to recall it because
set_all_choice_values() is called if SYMBOL_NEED_SET_CHOICE_VALUES
is set.

When sym_calc_choice() is called again, the choice symbol forgets it
forever, since SYMBOL_NEED_SET_CHOICE_VALUES is a one-time aid.
Hence, we cannot call sym_clear_all_valid() again and again.

It is crazy to repeat set and unset of internal flags. However, we
cannot simply get rid of "sym->flags &= flags | ~SYMBOL_DEF_USER;"
Doing so would re-introduce the problem solved by commit 5d09598d48
("kconfig: fix new choices being skipped upon config update").

To work around the issue, conf_write_autoconf() stopped calling
sym_clear_all_valid().

conf_write() must be changed accordingly. Currently, it clears
SYMBOL_WRITE after the symbol is written into the .config file. This
is needed to prevent it from writing the same symbol multiple times in
case the symbol is declared in two or more locations. I added the new
flag SYMBOL_WRITTEN, to track the symbols that have been written.

Anyway, this is a cheesy workaround in order to suppress the issue
as far as defconfig is concerned.

Handling of choices is totally broken. sym_clear_all_valid() is called
every time a user touches a symbol from the GUI interface. To reproduce
it, just add a new symbol drivers/usb/gadget/legacy/Kconfig, then touch
around unrelated symbols from menuconfig. USB_FUNCTIONFS will disappear
from the .config file.

I added the Fixes tag since it is more fatal than before. But, this
has been broken since long long time before, and still it is.
We should take a closer look to fix this correctly somehow.

Fixes: 00c864f890 ("kconfig: allow all config targets to write auto.conf if missing")
Cc: linux-stable <stable@vger.kernel.org> # 4.19+
Reported-by: Joonas Kylmälä <joonas.kylmala@iki.fi>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Joonas Kylmälä <joonas.kylmala@iki.fi>
2019-07-17 22:37:51 +09:00
Masahiro Yamada
3266c806dc kconfig: run olddefconfig instead of oldconfig after merging fragments
'make olddefconfig' is non-interactive, so we can drop 'yes'.
The behavior is equivalent.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-17 10:25:10 +09:00
Linus Torvalds
106f1466e7 Kconfig updates for v5.3
- always require argument for --defconfig and remove the hard-coded
   arch/$(ARCH)/defconfig path
 
 - make arch/$(SRCARCH)/configs/defconfig the new default of defconfig
 
 - some code cleanups
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Merge tag 'kconfig-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kconfig updates from Masahiro Yamada:

 - always require argument for --defconfig and remove the hard-coded
   arch/$(ARCH)/defconfig path

 - make arch/$(SRCARCH)/configs/defconfig the new default of defconfig

 - some code cleanups

* tag 'kconfig-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: remove meaningless if-conditional in conf_read()
  kconfig: Fix spelling of sym_is_changable
  unicore32: rename unicore32_defconfig to defconfig
  kconfig: make arch/*/configs/defconfig the default of KBUILD_DEFCONFIG
  kconfig: add static qualifier to expand_string()
  kconfig: require the argument of --defconfig
  kconfig: remove always false ifeq ($(KBUILD_DEFCONFIG,) conditional
2019-07-12 16:06:27 -07:00
Masahiro Yamada
e3cd5136a4 kconfig: remove meaningless if-conditional in conf_read()
sym_is_choice(sym) has already been checked by previous if-block:

    if (sym_is_choice(sym) || (sym->flags & SYMBOL_NO_WRITE))
            continue;

Hence, the following code is redundant, and the comment is misleading:

    if (!sym_is_choice(sym))
            continue;
    /* fall through */

It always takes 'continue', never falls though.

Clean up the dead code.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-11 23:37:55 +09:00
Marco Ammon
baa23ec860 kconfig: Fix spelling of sym_is_changable
There is a spelling mistake in "changable", it is corrected to
"changeable" and all call sites are updated accordingly.

Signed-off-by: Marco Ammon <marco.ammon@fau.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-06 21:58:23 +09:00
Mauro Carvalho Chehab
cd238effef docs: kbuild: convert docs to ReST and rename to *.rst
The kbuild documentation clearly shows that the documents
there are written at different times: some use markdown,
some use their own peculiar logic to split sections.

Convert everything to ReST without affecting too much
the author's style and avoiding adding uneeded markups.

The conversion is actually:
  - add blank lines and identation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-14 14:21:21 -06:00
Masahiro Yamada
bd305f259c kconfig: make arch/*/configs/defconfig the default of KBUILD_DEFCONFIG
Until recently, if KBUILD_DEFCONFIG was not set by the arch Makefile,
the default path arch/*/defconfig was used.

The last users of the default are gone by the following commits:

- Commit f3e20ad67b ("s390: move arch/s390/defconfig to
  arch/s390/configs/defconfig")

- Commit 986a13769c ("alpha: move arch/alpha/defconfig to
  arch/alpha/configs/defconfig")

Let's set arch/*/configs/defconfig as a new default. This saves
KBUILD_DEFCONFIG for some architectures.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2019-06-09 15:08:18 +09:00
Masahiro Yamada
5533397d1e kconfig: add static qualifier to expand_string()
Now expand_string() is only used in preprocess.c

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-06-09 15:08:18 +09:00
Masahiro Yamada
b6f7e9f705 kconfig: require the argument of --defconfig
Currently, the argument for --defconfig is optional. If the argument
is not passed, the hard-coded default arch/$(ARCH)/defconfig is used.

It no longer happens in Linux since the last users of the default are
gone by the following commits:

- Commit f3e20ad67b ("s390: move arch/s390/defconfig to
  arch/s390/configs/defconfig")

- Commit 986a13769c ("alpha: move arch/alpha/defconfig to
  arch/alpha/configs/defconfig")

I want to kill the Linux-specific directory path embedded in the
Kconfig binary.

The --savedefconfig (reverse operation of --defconfig) requires an
argument, so it should not hurt to do likewise for --defconfig.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-06-09 15:08:18 +09:00
Masahiro Yamada
e0a2668665 kconfig: remove always false ifeq ($(KBUILD_DEFCONFIG,) conditional
With the following two commits applied, all the arch Makefiles
define KBUILD_DEFCONFIG.

- Commit f3e20ad67b ("s390: move arch/s390/defconfig to
  arch/s390/configs/defconfig")

- Commit 986a13769c ("alpha: move arch/alpha/defconfig to
  arch/alpha/configs/defconfig")

The first conditional in the defconfig rule is always false.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-06-09 15:08:18 +09:00
Masahiro Yamada
8dde5715b2 kconfig: tests: fix recursive inclusion unit test
Adding SPDX license identifier is pretty safe; however, here is one
exception.

Since commit ec8f24b7fa ("treewide: Add SPDX license identifier -
Makefile/Kconfig"), "make testconfig" would not pass.

When Kconfig detects a circular file inclusion, it displays error
messages with a file name and a line number prefixed to each line.

The unit test checks if Kconfig emits the error messages correctly
(this also checks the line number correctness).

Now that the test input has the SPDX license identifier at the very top,
the line numbers in the expected stderr should be incremented by 1.

Fixes: ec8f24b7fa ("treewide: Add SPDX license identifier - Makefile/Kconfig")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-06-05 02:33:10 +09:00
Thomas Gleixner
ec8f24b7fa treewide: Add SPDX license identifier - Makefile/Kconfig
Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:46 +02:00
Masahiro Yamada
fc2694ec1a kconfig: use 'else ifneq' for Makefile to improve readability
'ifeq ... else ifneq ... endif' notation is supported by GNU Make 3.81
or later, which is the requirement for building the kernel since
commit 37d69ee308 ("docs: bump minimal GNU Make version to 3.81").

Use it to improve the readability.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-05-19 09:34:35 +09:00
Alexander Popov
aff11cd983 kconfig: Terminate menu blocks with a comment in the generated config
Currently menu blocks start with a pretty header but end with nothing in
the generated config. So next config options stick together with the
options from the menu block.

Let's terminate menu blocks in the generated config with a comment and
a newline if needed. Example:

...
CONFIG_BPF_STREAM_PARSER=y
CONFIG_NET_FLOW_LIMIT=y

#
# Network testing
#
CONFIG_NET_PKTGEN=y
CONFIG_NET_DROP_MONITOR=y
# end of Network testing
# end of Networking options

CONFIG_HAMRADIO=y
...

Signed-off-by: Alexander Popov <alex.popov@linux.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-05-18 15:31:24 +09:00
Masahiro Yamada
9cc342f6c4 treewide: prefix header search paths with $(srctree)/
Currently, the Kbuild core manipulates header search paths in a crazy
way [1].

To fix this mess, I want all Makefiles to add explicit $(srctree)/ to
the search paths in the srctree. Some Makefiles are already written in
that way, but not all. The goal of this work is to make the notation
consistent, and finally get rid of the gross hacks.

Having whitespaces after -I does not matter since commit 48f6e3cf5b
("kbuild: do not drop -I without parameter").

[1]: https://patchwork.kernel.org/patch/9632347/

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-05-18 11:49:57 +09:00
Masahiro Yamada
9b9f5948af kconfig: make conf_get_autoconfig_name() static
This is only used in confdata.c

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-05-14 23:23:25 +09:00
Jacob Garber
b9d1a8e930 kconfig: use snprintf for formatting pathnames
Valid pathnames will never exceed PATH_MAX, but these file names
are unsanitized and can cause buffer overflow if set incorrectly.
Use snprintf to avoid this. This was flagged during a Coverity scan
of the coreboot project, which also uses kconfig for its build system.

Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-05-14 23:23:25 +09:00
Masahiro Yamada
4cb726121e kconfig: remove useless NULL pointer check in conf_write_dep()
conf_write_dep() has just one caller:

    conf_write_dep("include/config/auto.conf.cmd");

"name" always points to a valid string.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-05-14 23:23:16 +09:00
Masahiro Yamada
580c5b3e1b kconfig: make parent directories for the saved .config as needed
With menuconfig / nconfig, users can input any file path from the
"Save" menu, but it fails if the parent directory does not exist.

Why not create the parent directory automatically. I think this is
a user-friendly behavior.

I changed the error messages in menuconfig / nconfig.

"Nonexistent directory" is no longer the most likely reason of the
failure. Perhaps, the user specified the existing directory, or
attempted to write to the location without write permission.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-05-11 02:16:21 +09:00
Masahiro Yamada
67424f61f8 kconfig: do not write .config if the content is the same
Kconfig updates the .config when it exits even if its content is
exactly the same as before. Since its timestamp becomes newer than
that of other build artifacts, additional processing is invoked,
which is annoying.

- syncconfig is invoked to update include/config/auto.conf, etc.

- kernel/configs.o is recompiled if CONFIG_IKCONFIG is enabled,
  then vmlinux is relinked as well.

If the .config is not changed at all, we do not have to even
touch it. Just bail out showing "No change to .config".

  $ make allmodconfig
  scripts/kconfig/conf  --allmodconfig Kconfig
  #
  # configuration written to .config
  #
  $ make allmodconfig
  scripts/kconfig/conf  --allmodconfig Kconfig
  #
  # No change to .config
  #

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-11 02:15:49 +09:00
Masahiro Yamada
ceb7f3296e kconfig: do not accept a directory for configuration output
Currently, conf_write() can be called with a directory name instead
of a file name. As far as I see, this can happen for menuconfig,
nconfig, gconfig.

If it is given with a directory path, conf_write() kindly appends
getenv("KCONFIG_CONFIG"), but this ends up with hacky dir/basename
handling, and screwed up in corner-cases like "what if KCONFIG_CONFIG
is an absolute path?" as discussed before:

  https://patchwork.kernel.org/patch/9910037/

Since conf_write() is already messed up, I'd say "do not do it".
Please pass a file path all the time. If a directory path is specified
for the configuration output, conf_write() will simply error out.

Now that the tmp file is created in the same directory as the .config,
the previously reported "what if KCONFIG_CONFIG points to a different
file system?" has been solved.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Nicolas Porcel <nicolasporcel06@gmail.com>
2019-05-11 02:14:27 +09:00