tinyconfig: remove unnecessary 'is not set' for choice blocks

This reverts the following commits:

- 236dec051078 ("kconfig: tinyconfig: provide whole choice blocks to
avoid warnings")

- b0f26

tinyconfig: remove unnecessary 'is not set' for choice blocks

This reverts the following commits:

- 236dec051078 ("kconfig: tinyconfig: provide whole choice blocks to
avoid warnings")

- b0f269728ccd ("x86/config: Fix warning for 'make ARCH=x86_64
tinyconfig'")

Since commit f79dc03fe68c ("kconfig: refactor choice value calculation"),
it is no longer necessary to disable the remaining options in choice
blocks.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>

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mm/slab: rename CONFIG_SLAB to CONFIG_SLAB_DEPRECATED

As discussed at LSF/MM [1] [2] and with no objections raised there,
deprecate the SLAB allocator. Rename the user-visible option so that
users w

mm/slab: rename CONFIG_SLAB to CONFIG_SLAB_DEPRECATED

As discussed at LSF/MM [1] [2] and with no objections raised there,
deprecate the SLAB allocator. Rename the user-visible option so that
users with CONFIG_SLAB=y get a new prompt with explanation during make
oldconfig, while make olddefconfig will just switch to SLUB.

In all defconfigs with CONFIG_SLAB=y remove the line so those also
switch to SLUB. Regressions due to the switch should be reported to
linux-mm and slab maintainers.

[1] https://lore.kernel.org/all/[email protected]/
[2] https://lwn.net/Articles/932201/

Signed-off-by: Vlastimil Babka <[email protected]>
Acked-by: Hyeonggon Yoo <[email protected]>
Acked-by: David Rientjes <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]> # m68k
Acked-by: Helge Deller <[email protected]> # parisc

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mm/slob: remove CONFIG_SLOB

Remove SLOB from Kconfig and Makefile. Everything under #ifdef
CONFIG_SLOB, and mm/slob.c is now dead code.

Signed-off-by: Vlastimil Babka <[email protected]>
Acked-by: Hye

mm/slob: remove CONFIG_SLOB

Remove SLOB from Kconfig and Makefile. Everything under #ifdef
CONFIG_SLOB, and mm/slob.c is now dead code.

Signed-off-by: Vlastimil Babka <[email protected]>
Acked-by: Hyeonggon Yoo <[email protected]>
Acked-by: Lorenzo Stoakes <[email protected]>
Acked-by: Mike Rapoport (IBM) <[email protected]>

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mm, slob: rename CONFIG_SLOB to CONFIG_SLOB_DEPRECATED

As explained in [1], we would like to remove SLOB if possible.

- There are no known users that need its somewhat lower memory footprint
so m

mm, slob: rename CONFIG_SLOB to CONFIG_SLOB_DEPRECATED

As explained in [1], we would like to remove SLOB if possible.

- There are no known users that need its somewhat lower memory footprint
so much that they cannot handle SLUB (after some modifications by the
previous patches) instead.

- It is an extra maintenance burden, and a number of features are
incompatible with it.

- It blocks the API improvement of allowing kfree() on objects allocated
via kmem_cache_alloc().

As the first step, rename the CONFIG_SLOB option in the slab allocator
configuration choice to CONFIG_SLOB_DEPRECATED. Add CONFIG_SLOB
depending on CONFIG_SLOB_DEPRECATED as an internal option to avoid code
churn. This will cause existing .config files and defconfigs with
CONFIG_SLOB=y to silently switch to the default (and recommended
replacement) SLUB, while still allowing SLOB to be configured by anyone
that notices and needs it. But those should contact the slab maintainers
and [email protected] as explained in the updated help. With no valid
objections, the plan is to update the existing defconfigs to SLUB and
remove SLOB in a few cycles.

To make SLUB more suitable replacement for SLOB, a CONFIG_SLUB_TINY
option was introduced to limit SLUB's memory overhead.
There is a number of defconfigs specifying CONFIG_SLOB=y. As part of
this patch, update them to select CONFIG_SLUB and CONFIG_SLUB_TINY.

[1] https://lore.kernel.org/all/[email protected]/

Cc: Russell King <[email protected]>
Cc: Aaro Koskinen <[email protected]>
Cc: Janusz Krzysztofik <[email protected]>
Cc: Tony Lindgren <[email protected]>
Cc: Jonas Bonn <[email protected]>
Cc: Stefan Kristiansson <[email protected]>
Cc: Stafford Horne <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Josh Triplett <[email protected]>
Cc: Conor Dooley <[email protected]>
Cc: Damien Le Moal <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Signed-off-by: Vlastimil Babka <[email protected]>
Acked-by: Aaro Koskinen <[email protected]> # OMAP1
Reviewed-by: Damien Le Moal <[email protected]> # riscv k210
Acked-by: Arnd Bergmann <[email protected]> # arm
Acked-by: Roman Gushchin <[email protected]>
Acked-by: Mike Rapoport <[email protected]>
Reviewed-by: Christoph Lameter <[email protected]>

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compiler: remove CONFIG_OPTIMIZE_INLINING entirely

Commit ac7c3e4ff401 ("compiler: enable CONFIG_OPTIMIZE_INLINING
forcibly") made this always-on option. We released v5.4 and v5.5
including that com

compiler: remove CONFIG_OPTIMIZE_INLINING entirely

Commit ac7c3e4ff401 ("compiler: enable CONFIG_OPTIMIZE_INLINING
forcibly") made this always-on option. We released v5.4 and v5.5
including that commit.

Remove the CONFIG option and clean up the code now.

Signed-off-by: Masahiro Yamada <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: Miguel Ojeda <[email protected]>
Reviewed-by: Nathan Chancellor <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: David Miller <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

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kconfig: tinyconfig: remove stale stack protector fixups

Prior to commit 2a61f4747eea ("stack-protector: test compiler capability
in Kconfig and drop AUTO mode"), the stack protector was configured

kconfig: tinyconfig: remove stale stack protector fixups

Prior to commit 2a61f4747eea ("stack-protector: test compiler capability
in Kconfig and drop AUTO mode"), the stack protector was configured by
the choice of NONE, REGULAR, STRONG, AUTO.

tiny.config needed to explicitly set NONE because the default value of
choice, AUTO, did not produce the tiniest kernel.

Now that there are only two boolean symbols, STACKPROTECTOR and
STACKPROTECTOR_STRONG, they are naturally disabled by "make
allnoconfig", which "make tinyconfig" is based on. Remove unnecessary
lines from the tiny.config fragment file.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Kees Cook <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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Makefile: introduce CONFIG_CC_STACKPROTECTOR_AUTO

Nearly all modern compilers support a stack-protector option, and nearly
all modern distributions enable the kernel stack-protector, so enabling
thi

Makefile: introduce CONFIG_CC_STACKPROTECTOR_AUTO

Nearly all modern compilers support a stack-protector option, and nearly
all modern distributions enable the kernel stack-protector, so enabling
this by default in kernel builds would make sense. However, Kconfig does
not have knowledge of available compiler features, so it isn't safe to
force on, as this would unconditionally break builds for the compilers or
architectures that don't have support. Instead, this introduces a new
option, CONFIG_CC_STACKPROTECTOR_AUTO, which attempts to discover the best
possible stack-protector available, and will allow builds to proceed even
if the compiler doesn't support any stack-protector.

This option is made the default so that kernels built with modern
compilers will be protected-by-default against stack buffer overflows,
avoiding things like the recent BlueBorne attack. Selection of a specific
stack-protector option remains available, including disabling it.

Additionally, tiny.config is adjusted to use CC_STACKPROTECTOR_NONE, since
that's the option with the least code size (and it used to be the default,
so we have to explicitly choose it there now).

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>
Tested-by: Laura Abbott <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Josh Triplett <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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kconfig: tinyconfig: provide whole choice blocks to avoid warnings

Using "make tinyconfig" produces a couple of annoying warnings that show
up for build test machines all the time:

.config:966:

kconfig: tinyconfig: provide whole choice blocks to avoid warnings

Using "make tinyconfig" produces a couple of annoying warnings that show
up for build test machines all the time:

.config:966:warning: override: NOHIGHMEM changes choice state
.config:965:warning: override: SLOB changes choice state
.config:963:warning: override: KERNEL_XZ changes choice state
.config:962:warning: override: CC_OPTIMIZE_FOR_SIZE changes choice state
.config:933:warning: override: SLOB changes choice state
.config:930:warning: override: CC_OPTIMIZE_FOR_SIZE changes choice state
.config:870:warning: override: SLOB changes choice state
.config:868:warning: override: KERNEL_XZ changes choice state
.config:867:warning: override: CC_OPTIMIZE_FOR_SIZE changes choice state

I've made a previous attempt at fixing them and we discussed a number of
alternatives.

I tried changing the Makefile to use "merge_config.sh -n
$(fragment-list)" but couldn't get that to work properly.

This is yet another approach, based on the observation that we do want
to see a warning for conflicting 'choice' options, and that we can
simply make them non-conflicting by listing all other options as
disabled. This is a trivial patch that we can apply independent of
plans for other changes.

Link: http://lkml.kernel.org/r/[email protected]
Link: https://storage.kernelci.org/mainline/v4.7-rc6/x86-tinyconfig/build.log
https://patchwork.kernel.org/patch/9212749/
Signed-off-by: Arnd Bergmann <[email protected]>
Reviewed-by: Josh Triplett <[email protected]>
Reviewed-by: Masahiro Yamada <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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x86: Add "make tinyconfig" to configure the tiniest possible kernel

Since commit 5d2acfc7b974bbd3858b4dd3f2cdc6362dd8843a ("kconfig: make
allnoconfig disable options behind EMBEDDED and EXPERT") in

x86: Add "make tinyconfig" to configure the tiniest possible kernel

Since commit 5d2acfc7b974bbd3858b4dd3f2cdc6362dd8843a ("kconfig: make
allnoconfig disable options behind EMBEDDED and EXPERT") in 3.15-rc1,
"make allnoconfig" disables every possible config option.

However, a few configuration options (CC_OPTIMIZE_FOR_SIZE,
OPTIMIZE_INLINING) produce a smaller kernel when turned on, and a few
choices exist (compression, highmem, allocator) for which a non-default
option produces a smaller kernel.

Add a "tinyconfig" option, which starts from allnoconfig and then sets
these options to configure the tiniest possible kernel. This provides a
better baseline for embedded systems or efforts to reduce kernel size.

Signed-off-by: Josh Triplett <[email protected]>

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