Commit Graph

792 Commits

Author SHA1 Message Date
Jerry James
73d1c580f9 kconfig: loop boundary condition fix
If buf[-1] just happens to hold the byte 0x0A, then nread can wrap around
to (size_t)-1, leading to invalid memory accesses.

This has caused segmentation faults when trying to build the latest
kernel snapshots for i686 in Fedora:
https://bugzilla.redhat.com/show_bug.cgi?id=1592374

Signed-off-by: Jerry James <loganjerry@gmail.com>
[alexpl@fedoraproject.org: reformatted patch for submission]
Signed-off-by: Alexander Ploumistos <alexpl@fedoraproject.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-28 22:48:08 +09:00
Dirk Gouders
ecd53ac2f2 kconfig: handle P_SYMBOL in print_symbol()
Each symbol has a property of type P_SYMBOL since commit
59e89e3ddf (kconfig: save location of config symbols).
Handle those properties in print_symbol().

Further, place a pointer to print_symbol() in the comment above the
list of known property type.

Signed-off-by: Dirk Gouders <dirk@gouders.net>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-28 22:47:47 +09:00
Dirk Gouders
b2d00d7c61 kconfig: fix line numbers for if-entries in menu tree
The line numers for if-entries in the menu tree are off by one or more
lines which is confusing when debugging for correctness of unrelated changes.

According to the git log, commit a02f0570ae (kconfig: improve
error handling in the parser) was the last one that changed that part
of the parser and replaced

	"if_entry: T_IF expr T_EOL"
by
	"if_entry: T_IF expr nl"

but the commit message does not state why this has been done.

When reverting that part of the commit, only the line numers are
corrected (checked with cdebug = DEBUG_PARSE in zconf.y), otherwise
the menu tree remains unchanged (checked with zconfdump() enabled in
conf.c).

An example for the corrected line numbers:

drivers/soc/Kconfig:15:source drivers/soc/tegra/Kconfig
drivers/soc/tegra/Kconfig:4:if
drivers/soc/tegra/Kconfig:6:if

changes to:

drivers/soc/Kconfig:15:source drivers/soc/tegra/Kconfig
drivers/soc/tegra/Kconfig:1:if
drivers/soc/tegra/Kconfig:4:if

Signed-off-by: Dirk Gouders <dirk@gouders.net>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-25 23:21:14 +09:00
Sam Ravnborg
8593080c0f kconfig: fix localmodconfig
When kconfig syntax moved to use $(FOO) for environment variables
localmodconfig was not updated.
Fix so it now works with the new syntax $(FOO)

Fixes: 104daea149 ("kconfig: reference environment variables directly and remove 'option env='")
Reported-by: Kevin Locke <kevin@kevinlocke.name>
Reported-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Tested-by: Kevin Locke <kevin@kevinlocke.name>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-11 09:16:30 +09:00
Nathan Chancellor
2ae89c7a82 kconfig: Avoid format overflow warning from GCC 8.1
In file included from scripts/kconfig/zconf.tab.c:2485:
scripts/kconfig/confdata.c: In function ‘conf_write’:
scripts/kconfig/confdata.c:773:22: warning: ‘%s’ directive writing likely 7 or more bytes into a region of size between 1 and 4097 [-Wformat-overflow=]
  sprintf(newname, "%s%s", dirname, basename);
                      ^~
scripts/kconfig/confdata.c:773:19: note: assuming directive output of 7 bytes
  sprintf(newname, "%s%s", dirname, basename);
                   ^~~~~~
scripts/kconfig/confdata.c:773:2: note: ‘sprintf’ output 1 or more bytes (assuming 4104) into a destination of size 4097
  sprintf(newname, "%s%s", dirname, basename);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
scripts/kconfig/confdata.c:776:23: warning: ‘.tmpconfig.’ directive writing 11 bytes into a region of size between 1 and 4097 [-Wformat-overflow=]
   sprintf(tmpname, "%s.tmpconfig.%d", dirname, (int)getpid());
                       ^~~~~~~~~~~
scripts/kconfig/confdata.c:776:3: note: ‘sprintf’ output between 13 and 4119 bytes into a destination of size 4097
   sprintf(tmpname, "%s.tmpconfig.%d", dirname, (int)getpid());
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Increase the size of tmpname and newname to make GCC happy.

Cc: stable@vger.kernel.org
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-05 22:07:21 +09:00
Petr Vorel
bb6d83dde1 kbuild: Move last word of nconfig help to the previous line
Signed-off-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-05 22:07:03 +09:00
Petr Vorel
d6a0c8a132 kconfig: Add testconfig into make help output
Signed-off-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-05 22:06:32 +09:00
Masahiro Yamada
2bece88f89 kconfig: test: add Kconfig macro language tests
Here are the test cases I used for developing the text expansion
feature.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
915f64901e kconfig: error out if a recursive variable references itself
When using a recursively expanded variable, it is a common mistake
to make circular reference.

For example, Make terminates the following code:

  X = $(X)
  Y := $(X)

Let's detect the circular expansion in Kconfig, too.

On the other hand, a function that recurses itself is a commonly-used
programming technique.  So, Make does not check recursion in the
reference with 'call'.  For example, the following code continues
running eternally:

  X = $(call X)
  Y := $(X)

Kconfig allows circular expansion if one or more arguments are given,
but terminates when the same function is recursively invoked 1000 times,
assuming it is a programming mistake.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
a702a6176e kconfig: add 'filename' and 'lineno' built-in variables
The special variables, $(filename) and $(lineno), are expanded to a
file name and its line number being parsed, respectively.

Suggested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
1d6272e6fe kconfig: add 'info', 'warning-if', and 'error-if' built-in functions
Syntax:
  $(info,<text>)
  $(warning-if,<condition>,<text>)
  $(error-if,<condition>,<text)

The 'info' function prints a message to stdout as in Make.

The 'warning-if' and 'error-if' are similar to 'warning' and 'error'
in Make, but take the condition parameter.  They are effective only
when the <condition> part is y.

Kconfig does not implement the lazy expansion as used in the 'if'
'and, 'or' functions in Make.  In other words, Kconfig does not
support conditional expansion.  The unconditional 'error' function
would always terminate the parsing, hence would be useless in Kconfig.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
82bc8bd82e kconfig: expand lefthand side of assignment statement
Make expands the lefthand side of assignment statements.  In fact,
Kbuild relies on it since kernel makefiles mostly look like this:

  obj-$(CONFIG_FOO) += foo.o

Do likewise in Kconfig.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
ed2a22f277 kconfig: support append assignment operator
Support += operator.  This appends a space and the text on the
righthand side to a variable.

The timing of the evaluation of the righthand side depends on the
flavor of the variable.  If the lefthand side was originally defined
as a simple variable, the righthand side is expanded immediately.
Otherwise, the expansion is deferred.  Appending something to an
undefined variable results in a recursive variable.

To implement this, we need to remember the flavor of variables.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
1175c02506 kconfig: support simply expanded variable
The previous commit added variable and user-defined function.  They
work similarly in the sense that the evaluation is deferred until
they are used.

This commit adds another type of variable, simply expanded variable,
as we see in Make.

The := operator defines a simply expanded variable, expanding the
righthand side immediately.  This works like traditional programming
language variables.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
9ced3bddec kconfig: support user-defined function and recursively expanded variable
Now, we got a basic ability to test compiler capability in Kconfig.

config CC_HAS_STACKPROTECTOR
        def_bool $(shell,($(CC) -Werror -fstack-protector -E -x c /dev/null -o /dev/null 2>/dev/null) && echo y || echo n)

This works, but it is ugly to repeat this long boilerplate.

We want to describe like this:

config CC_HAS_STACKPROTECTOR
        bool
        default $(cc-option,-fstack-protector)

It is straight-forward to add a new function, but I do not like to
hard-code specialized functions like that.  Hence, here is another
feature, user-defined function.  This works as a textual shorthand
with parameterization.

A user-defined function is defined by using the = operator, and can
be referenced in the same way as built-in functions.  A user-defined
function in Make is referenced like $(call my-func,arg1,arg2), but I
omitted the 'call' to make the syntax shorter.

The definition of a user-defined function contains $(1), $(2), etc.
in its body to reference the parameters.  It is grammatically valid
to pass more or fewer arguments when calling it.  We already exploit
this feature in our makefiles; scripts/Kbuild.include defines cc-option
which takes two arguments at most, but most of the callers pass only
one argument.

By the way, a variable is supported as a subset of this feature since
a variable is "a user-defined function with zero argument".  In this
context, I mean "variable" as recursively expanded variable.  I will
add a different flavored variable in the next commit.

The code above can be written as follows:

[Example Code]

  success = $(shell,($(1)) >/dev/null 2>&1 && echo y || echo n)
  cc-option = $(success,$(CC) -Werror $(1) -E -x c /dev/null -o /dev/null)

  config CC_HAS_STACKPROTECTOR
          def_bool $(cc-option,-fstack-protector)

[Result]
  $ make -s alldefconfig && tail -n 1 .config
  CONFIG_CC_HAS_STACKPROTECTOR=y

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
9de071536c kconfig: begin PARAM state only when seeing a command keyword
Currently, any statement line starts with a keyword with TF_COMMAND
flag.  So, the following three lines are dead code.

        alloc_string(yytext, yyleng);
        zconflval.string = text;
        return T_WORD;

If a T_WORD token is returned in this context, it will cause syntax
error in the parser anyway.

The next commit will support the assignment statement where a line
starts with an arbitrary identifier.  So, I want the lexer to switch
to the PARAM state only when it sees a command keyword.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
2fd5b09c20 kconfig: add 'shell' built-in function
This accepts a single command to execute.  It returns the standard
output from it.

[Example code]

  config HELLO
          string
          default "$(shell,echo hello world)"

  config Y
          def_bool $(shell,echo y)

[Result]

  $ make -s alldefconfig && tail -n 2 .config
  CONFIG_HELLO="hello world"
  CONFIG_Y=y

Caveat:
Like environments, functions are expanded in the lexer.  You cannot
pass symbols to function arguments.  This is a limitation to simplify
the implementation.  I want to avoid the dynamic function evaluation,
which would introduce much more complexity.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
e298f3b49d kconfig: add built-in function support
This commit adds a new concept 'function' to do more text processing
in Kconfig.

A function call looks like this:

  $(function,arg1,arg2,arg3,...)

This commit adds the basic infrastructure to expand functions.
Change the text expansion helpers to take arguments.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
137c0118a9 kconfig: make default prompt of mainmenu less specific
If "mainmenu" is not specified, "Linux Kernel Configuration" is used
as a default prompt.

Given that Kconfig is used in other projects than Linux, let's use
a more generic prompt, "Main menu".

Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
5b31a97467 kconfig: remove sym_expand_string_value()
There is no more caller of sym_expand_string_value().

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
96d8e48da5 kconfig: remove string expansion for mainmenu after yyparse()
Now that environments are expanded in the lexer, conf_parse() does
not need to expand them explicitly.

The hack introduced by commit 0724a7c32a ("kconfig: Don't leak
main menus during parsing") can go away.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
bb222ceeb3 kconfig: remove string expansion in file_lookup()
There are two callers of file_lookup(), but there is no more reason
to expand the given path.

[1] zconf_initscan()
    This is used to open the first Kconfig.  sym_expand_string_value()
    has never been used in a useful way here; before opening the first
    Kconfig file, obviously there is no symbol to expand.  If you use
    expand_string_value() instead, environments in KBUILD_KCONFIG would
    be expanded, but I do not see practical benefits for that.

[2] zconf_nextfile()
    This is used to open the next file from 'source' statement.
    Symbols in the path like "arch/$SRCARCH/Kconfig" needed expanding,
    but it was replaced with the direct environment expansion.  The
    environment has already been expanded before the token is passed
    to the parser.

By the way, file_lookup() was already buggy; it expanded a given path,
but it used the path before expansion for look-up:
        if (!strcmp(name, file->name)) {

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
2018-05-29 03:28:58 +09:00
Masahiro Yamada
104daea149 kconfig: reference environment variables directly and remove 'option env='
To get access to environment variables, Kconfig needs to define a
symbol using "option env=" syntax.  It is tedious to add a symbol entry
for each environment variable given that we need to define much more
such as 'CC', 'AS', 'srctree' etc. to evaluate the compiler capability
in Kconfig.

Adding '$' for symbol references is grammatically inconsistent.
Looking at the code, the symbols prefixed with 'S' are expanded by:
 - conf_expand_value()
   This is used to expand 'arch/$ARCH/defconfig' and 'defconfig_list'
 - sym_expand_string_value()
   This is used to expand strings in 'source' and 'mainmenu'

All of them are fixed values independent of user configuration.  So,
they can be changed into the direct expansion instead of symbols.

This change makes the code much cleaner.  The bounce symbols 'SRCARCH',
'ARCH', 'SUBARCH', 'KERNELVERSION' are gone.

sym_init() hard-coding 'UNAME_RELEASE' is also gone.  'UNAME_RELEASE'
should be replaced with an environment variable.

ARCH_DEFCONFIG is a normal symbol, so it should be simply referenced
without '$' prefix.

The new syntax is addicted by Make.  The variable reference needs
parentheses, like $(FOO), but you can omit them for single-letter
variables, like $F.  Yet, in Makefiles, people tend to use the
parenthetical form for consistency / clarification.

At this moment, only the environment variable is supported, but I will
extend the concept of 'variable' later on.

The variables are expanded in the lexer so we can simplify the token
handling on the parser side.

For example, the following code works.

[Example code]

  config MY_TOOLCHAIN_LIST
          string
          default "My tools: CC=$(CC), AS=$(AS), CPP=$(CPP)"

[Result]

  $ make -s alldefconfig && tail -n 1 .config
  CONFIG_MY_TOOLCHAIN_LIST="My tools: CC=gcc, AS=as, CPP=gcc -E"

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2018-05-29 03:28:58 +09:00
Sam Ravnborg
694c49a7c0 kconfig: drop localization support
The localization support is broken and appears unused.
There is no google hits on the update-po-config target.
And there is no recent (5 years) activity related to the localization.

So lets just drop this as it is no longer used.

Suggested-by: Ulf Magnusson <ulfalizer@gmail.com>
Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-28 18:25:21 +09:00
Masahiro Yamada
1c5af5cf93 kconfig: refactor ncurses package checks for building mconf and nconf
The mconf (or its infrastructure, lxdiaglog) depends on the ncurses.
Move and rename check-lxdialog.sh to mconf-cfg.sh to make it work in
the same way as for qconf and gconf.

This commit fixes some more weirdnesses.

The nconf also needs ncurses packages.  HOSTLOADLIBES_nconf is set
to the libraries needed for nconf, but the cflags is not explicitly
set.  Actually, nconf relies on the check-lxdialog.sh for the proper
cflags:

HOST_EXTRACFLAGS += $(shell $(CONFIG_SHELL) $(check-lxdialog) -ccflags) \
                    -DLOCALE

The code above passes the ncurses flags to all objects, even for conf,
qconf, gconf.  Let's pass the ncurses flags only to mconf and nconf.

Currently, the presence of ncurses is not checked for nconf.  Let's
show a prompt like the mconf case.

According to Randy's report, the shell scripts still need to carry
the fallback code in case the pkg-config fails to find the ncurses
packages.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
2018-05-28 18:25:21 +09:00