linux.git/scripts/kconfig, branch v4.2-rc2

Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

2015-07-02T21:53:01+00:00

Pull kconfig updates from Michal Marek:

 - kconfig conditions can use usual less/greater than comparisons

 - kconfig warns about stray characters in Kconfig files

 - bogus expression simplification removed

 - some minor fixes

* 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kconfig: re-generate *.c_shipped files after previous change
  kconfig: allow use of relations other than (in)equality
  kconfig: don't silently ignore unhandled characters
  kconfig: Wrap long "make help" text lines
  scripts/kconfig/Makefile: Cosmetic fixes
  scripts/kconfig/Makefile: Fix spelling of Qt
  Kconfig: Remove bad inference rules expr_eliminate_dups2()

kconfig: add xenconfig defconfig helper

2015-06-16T10:04:29+00:00

This lets you build a kernel which can support xen dom0
or xen guests on i386, x86-64 and arm64 by just using:

   make xenconfig

You can start from an allnoconfig and then switch to xenconfig.
This also splits out the options which are available currently
to be built with x86 and 'make ARCH=arm64' under a shared config.

Technically xen supports a dom0 kernel and also a guest
kernel configuration but upon review with the xen team
since we don't have many dom0 options its best to just
combine these two into one.

A few generic notes: we enable both of these:

CONFIG_INET=y
CONFIG_BINFMT_ELF=y

although technically not required given you likely will
end up with a pretty useless system otherwise.

A few architectural differences worth noting:

$ make allnoconfig; make xenconfig > /dev/null ; \
	grep XEN .config > 64-bit-config
$ make ARCH=i386 allnoconfig; make ARCH=i386 xenconfig > /dev/null; \
	grep XEN .config > 32-bit-config
$ make ARCH=arm64 allnoconfig; make ARCH=arm64 xenconfig > /dev/null; \
	grep XEN .config > arm64-config

Since the options are already split up with a generic config and
architecture specific configs you anything on the x86 configs
are known to only work right now on x86. For instance arm64 doesn't
support MEMORY_HOTPLUG yet as such although we try to enabe it
generically arm64 doesn't have it yet, so we leave the xen
specific kconfig option XEN_BALLOON_MEMORY_HOTPLUG on x86's config
file to set expecations correctly.

Then on x86 we have differences between i386 and x86-64. The difference
between 64-bit-config and 32-bit-config is you don't get XEN_MCE_LOG as
this is only supported on 64-bit. You also do not get on i386
XEN_BALLOON_MEMORY_HOTPLUG, there does not seem to be any technical
reasons to not allow this but I gave up after a few attempts.

Cc: Josh Triplett 
Cc: Borislav Petkov 
Cc: Pekka Enberg 
Cc: David Rientjes 
Cc: Michal Marek 
Cc: Randy Dunlap 
Cc: penberg@kernel.org
Cc: levinsasha928@gmail.com
Cc: mtosatti@redhat.com
Cc: fengguang.wu@intel.com
Cc: David Vrabel 
Cc: Ian Campbell 
Cc: Konrad Rzeszutek Wilk 
Cc: xen-devel@lists.xenproject.org
Acked-by: Stefano Stabellini 
Acked-by: Julien Grall 
Acked-by: Michal Marek 
Acked-by: David Rientjes 
Reviewed-by: Josh Triplett 
Signed-off-by: Luis R. Rodriguez 
Signed-off-by: David Vrabel

kconfig: clarify kvmconfig is for kvm

2015-06-16T10:04:21+00:00

We'll be adding options for xen as well.

Cc: Josh Triplett 
Cc: Borislav Petkov 
Cc: Pekka Enberg 
Cc: David Rientjes 
Cc: Michal Marek 
Cc: Randy Dunlap 
Cc: penberg@kernel.org
Cc: levinsasha928@gmail.com
Cc: mtosatti@redhat.com
Cc: fengguang.wu@intel.com
Cc: David Vrabel 
Cc: Ian Campbell 
Cc: Konrad Rzeszutek Wilk 
Cc: xen-devel@lists.xenproject.org
Reviewed-by: Josh Triplett 
Acked-by: David Rientjes 
Acked-by: Borislav Petkov 
Acked-by: Michal Marek 
Signed-off-by: Luis R. Rodriguez 
Signed-off-by: David Vrabel

kconfig: re-generate *.c_shipped files after previous change

2015-06-15T12:05:58+00:00

Signed-off-by: Jan Beulich 
Signed-off-by: Michal Marek

kconfig: allow use of relations other than (in)equality

2015-06-15T12:05:58+00:00

Over the years I found it desirable to be able to use all sorts of
relations, not just (in)equality. And apparently I'm not the only one,
as there's at least one example in the tree where the programmer
assumed this would work (see DEBUG_UART_8250_WORD in
arch/arm/Kconfig.debug). Another possible use would e.g. be to fold the
two SMP/NR_CPUS prompts into one: SMP could be promptless, simply
depending on NR_CPUS > 1.

A (desirable) side effect of this change - resulting from numeric
values now necessarily being compared as numbers rather than as
strings - is that comparing hex values now works as expected: Other
than int ones (which aren't allowed to have leading zeroes), zeroes
following the 0x prefix made them compare unequal even if their values
were equal.

Signed-off-by: Jan Beulich 
Signed-off-by: Michal Marek

kconfig: don't silently ignore unhandled characters

2015-06-11T12:25:56+00:00

At the very least we should tell people that what they wrote is not
what the utility understands.

Signed-off-by: Jan Beulich 
Acked-by: Paul Bolle 
Signed-off-by: Michal Marek

kconfig: Wrap long "make help" text lines

2015-06-04T14:41:47+00:00

Some "make help" text lines extend beyond 80 characters. Wrap them at 79
characters.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Michal Marek

scripts/kconfig/Makefile: Cosmetic fixes

2015-06-03T08:56:12+00:00

Signed-off-by: Diego Viola 
Signed-off-by: Michal Marek

scripts/kconfig/Makefile: Fix spelling of Qt

2015-05-28T08:27:02+00:00

Signed-off-by: Diego Viola 
Signed-off-by: Michal Marek

Kconfig: Remove bad inference rules expr_eliminate_dups2()

2015-05-25T08:04:12+00:00

expr_eliminate_dups2() in scripts/kconfig/expr.c applies two invalid
inference rules:

(FOO || BAR) && (!FOO && !BAR) -> n
(FOO && BAR) || (!FOO || !BAR) -> y

They would be correct in propositional logic, but this is a three-valued
logic, and here it is wrong in that it changes semantics. It becomes
immediately visible when assigning the value 1 to both, FOO and BAR:

(FOO || BAR) && (!FOO && !BAR)
-> min(max(1, 1), min(2-1, 2-1)) = min(1, 1) = 1

while n evaluates to 0 and

(FOO && BAR) || (!FOO || !BAR)
-> max(min(1, 1), max(2-1, 2-1)) = max(1, 1) = 1

with y evaluating to 2.

Fix it by removing expr_eliminate_dups2() and the functions that have no
use anywhere else: expr_extract_eq_and(), expr_extract_eq_or(),
and expr_extract_eq() from scripts/kconfig/expr.c

Currently the bug is not triggered in mainline, so this patch does not
modify the configuration space there. To observe the bug consider this
example:

config MODULES
        def_bool y
        option modules

config FOO
        def_tristate m

config BAR
        def_tristate m

config TEST1
        def_tristate y
        depends on (FOO || BAR) && (!FOO && !BAR)

if TEST1 = n
comment "TEST1 broken"
endif

config TEST2
        def_tristate y
        depends on (FOO && BAR) || (!FOO || !BAR)

if TEST2 = y
comment "TEST2 broken"
endif

config TEST3
        def_tristate y
        depends on m && !m

if TEST3 = n
comment "TEST3 broken"
endif

TEST1, TEST2 and TEST3 should all evaluate to m, but without the patch,
none of them does. It is probably not obvious that TEST3 is the same bug,
but it becomes clear when considering what happens internally to the
expression
m && !m":
First it expands to
(m && MODULES) && !(m && MODULES),
then it is transformed into
(m && MODULES) && (!m || !MODULES),
and finally due to the bug it is replaced with n.

As a side effect, this patch reduces code size in expr.c by roughly 10%
and slightly improves startup time for all configuration frontends.

Signed-off-by: Martin Walch 
Signed-off-by: Michal Marek