user/sven/linux.git/usr, branch v4.12.5

initramfs: fix disabling of initramfs (and its compression)

2017-06-02T22:07:37Z

Commit db2aa7fd15e8 ("initramfs: allow again choice of the embedded initram compression algorithm") introduced the possibility to select the initramfs compression algorithm from Kconfig and while this is a nice feature it broke the use case described below. Here is what my build system does: - kernel is initially configured not to have an initramfs included - build the user space root file system - re-configure the kernel to have an initramfs included (CONFIG_INITRAMFS_SOURCE="/path/to/romfs") and set relevant CONFIG_INITRAMFS options, in my case, no compression option (CONFIG_INITRAMFS_COMPRESSION_NONE) - kernel is re-built with these options -> kernel+initramfs image is copied - kernel is re-built again without these options -> kernel image is copied Building a kernel without an initramfs means setting this option: CONFIG_INITRAMFS_SOURCE="" (and this one only) whereas building a kernel with an initramfs means setting these options: CONFIG_INITRAMFS_SOURCE="/home/fainelli/work/uclinux-rootfs/romfs /home/fainelli/work/uclinux-rootfs/misc/initramfs.dev" CONFIG_INITRAMFS_ROOT_UID=1000 CONFIG_INITRAMFS_ROOT_GID=1000 CONFIG_INITRAMFS_COMPRESSION_NONE=y CONFIG_INITRAMFS_COMPRESSION="" Commit db2aa7fd15e85 ("initramfs: allow again choice of the embedded initram compression algorithm") is problematic because CONFIG_INITRAMFS_COMPRESSION which is used to determine the initramfs_data.cpio extension/compression is a string, and due to how Kconfig works it will evaluate in order, how to assign it. Setting CONFIG_INITRAMFS_COMPRESSION_NONE with CONFIG_INITRAMFS_SOURCE="" cannot possibly work (because of the depends on INITRAMFS_SOURCE!="" imposed on CONFIG_INITRAMFS_COMPRESSION ) yet we still get CONFIG_INITRAMFS_COMPRESSION assigned to ".gz" because CONFIG_RD_GZIP=y is set in my kernel, even when there is no initramfs being built. So we basically end-up generating two initramfs_data.cpio* files, one without extension, and one with .gz. This causes usr/Makefile to track usr/initramfs_data.cpio.gz, and not usr/initramfs_data.cpio anymore, that is also largely problematic after 9e3596b0c6539e ("kbuild: initramfs cleanup, set target from Kconfig") because we used to track all possible initramfs_data files in the $(targets) variable before that commit. The end result is that the kernel with an initramfs clearly does not contain what we expect it to, it has a stale initramfs_data.cpio file built into it, and we keep re-generating an initramfs_data.cpio.gz file which is not the one that we want to include in the kernel image proper. The fix consists in hiding CONFIG_INITRAMFS_COMPRESSION when CONFIG_INITRAMFS_SOURCE="". This puts us back in a state to the pre-4.10 behavior where we can properly disable and re-enable initramfs within the same kernel .config file, and be in control of what CONFIG_INITRAMFS_COMPRESSION is set to. Fixes: db2aa7fd15e8 ("initramfs: allow again choice of the embedded initram compression algorithm") Fixes: 9e3596b0c653 ("kbuild: initramfs cleanup, set target from Kconfig") Link: http://lkml.kernel.org/r/20170521033337.6197-1-f.fainelli@gmail.com Signed-off-by: Florian Fainelli Acked-by: Nicholas Piggin Cc: P J P Cc: Paul Bolle Cc: Michal Marek Cc: Daniel Thompson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

initramfs: provide a way to ignore image provided by bootloader

2017-05-09T00:15:12Z

Many "embedded" architectures provide CMDLINE_FORCE to allow the kernel to override the command line provided by an inflexible bootloader. However there is currrently no way for the kernel to override the initramfs image provided by the bootloader meaning there are still ways for bootloaders to make things difficult for us. Fix this by introducing INITRAMFS_FORCE which can prevent the kernel from loading the bootloader supplied image. We use CMDLINE_FORCE (and its friend CMDLINE_EXTEND) to imply that the system has an inflexible bootloader. This allow us to avoid presenting this config option to users of systems where inflexible bootloaders aren't usually a problem. Link: http://lkml.kernel.org/r/20170217121940.30126-1-daniel.thompson@linaro.org Signed-off-by: Daniel Thompson Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kbuild: initramfs cleanup, set target from Kconfig

2017-01-05T17:40:16Z

Rather than keep a list of all possible compression types in the Makefile, set the target explicitly from Kconfig. Reviewed-by: Francisco Blas Izquierdo Riera (klondike) Signed-off-by: Nicholas Piggin Signed-off-by: Linus Torvalds

kbuild: initramfs fix dependency checking for compressed target

2017-01-05T17:40:16Z

When using initramfs compression, the data file compression suffix gets quotes pulled in from Kconfig, e.g., initramfs_data.cpio".gz" which make does not match a target and causes rebuild. Fix this by filtering out quotes from the Kconfig string. Fixes: 35e669e1a254 ("initramfs: select builtin initram compression algorithm on KConfig instead of Makefile") Reviewed-by: Francisco Blas Izquierdo Riera (klondike) Signed-off-by: Nicholas Piggin Signed-off-by: Linus Torvalds

initramfs: allow again choice of the embedded initram compression algorithm

2016-12-15T00:04:08Z

Choosing the appropriate compression option when using an embedded initramfs can result in significant size differences in the resulting data. This is caused by avoiding double compression of the initramfs contents. For example on my tests, choosing CONFIG_INITRAMFS_COMPRESSION_NONE when compressing the kernel using XZ) results in up to 500KiB differences (9MiB to 8.5MiB) in the kernel size as the dictionary will not get polluted with uncomprensible data and may reuse kernel data too. Despite embedding an uncompressed initramfs, a user may want to allow for a compressed extra initramfs to be passed using the rd system, for example to boot a recovery system. 9ba4bcb645898d ("initramfs: read CONFIG_RD_ variables for initramfs compression") broke that behavior by making the choice based on CONFIG_RD_* instead of adding CONFIG_INITRAMFS_COMPRESSION_LZ4. Saddly, CONFIG_RD_* is also used to choose the supported RD compression algorithms by the kernel and a user may want to support more than one. This patch also reverts commit 3e4e0f0a875 ("initramfs: remove "compression mode" choice") restoring back the "compression mode" choice and includes the CONFIG_INITRAMFS_COMPRESSION_LZ4 option which was never added. As a result the following options are added or readed affecting the embedded initramfs compression: INITRAMFS_COMPRESSION_NONE Do no compression INITRAMFS_COMPRESSION_GZIP Compress using gzip INITRAMFS_COMPRESSION_BZIP2 Compress using bzip2 INITRAMFS_COMPRESSION_LZMA Compress using lzma INITRAMFS_COMPRESSION_XZ Compress using xz INITRAMFS_COMPRESSION_LZO Compress using lzo INITRAMFS_COMPRESSION_LZ4 Compress using lz4 These depend on the corresponding CONFIG_RD_* option being set (except NONE which has no dependencies). This patch depends on the previous one (the previous version didn't) to simplify the way in which the algorithm is chosen and keep backwards compatibility with the behaviour introduced by 9ba4bcb645898 ("initramfs: read CONFIG_RD_ variables for initramfs compression"). Link: http://lkml.kernel.org/r/57EAD77B.7090607@klondike.es Signed-off-by: Francisco Blas Izquierdo Riera (klondike) Cc: P J P Cc: Paul Bolle Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

initramfs: select builtin initram compression algorithm on KConfig instead of Makefile

2016-12-15T00:04:08Z

Move the current builtin initram compression algorithm selection from the Makefile into the INITRAMFS_COMPRESSION variable. This makes deciding algorithm precedence easier and would allow for overrides if new algorithms want to be tested. Link: http://lkml.kernel.org/r/57EAD769.1090401@klondike.es Signed-off-by: Francisco Blas Izquierdo Riera (klondike) Cc: P J P Cc: Paul Bolle Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

usr/Kconfig: make initrd compression algorithm selection not expert

2014-12-13T20:42:52Z

The kernel has support for (nearly) every compression algorithm known to man, each to handle some particular microscopic niche. Unfortunately all of these always get compiled in if you want to support INITRDs, and can be only disabled when CONFIG_EXPERT is set. I don't see why I need to set EXPERT just to properly configure the initrd compression algorithms, and not always include every possible algorithm Usually the initrd is just compressed with gzip anyways, at least that's true on all distributions I use. Remove the dependencies for initrd compression on CONFIG_EXPERT. Make the various options just default y, which should be good enough to not break any previous configuration. Signed-off-by: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

initramfs: remove "compression mode" choice

2014-06-06T23:08:14Z

Commit 9ba4bcb64589 ("initramfs: read CONFIG_RD_ variables for initramfs compression") removed the users of the various INITRAMFS_COMPRESSION_* Kconfig symbols. So since v3.13 the entire "Built-in initramfs compression mode" choice is a set of knobs connected to nothing. The entire choice can safely be removed. Signed-off-by: Paul Bolle Cc: P J P Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

initramfs: read CONFIG_RD_ variables for initramfs compression

2013-11-13T03:09:26Z

When expert configuration option(CONFIG_EXPERT) is enabled, menuconfig offers a choice of compression algorithm to compress initial ramfs image; This choice is stored into CONFIG_RD_* variables. But usr/Makefile uses earlier INITRAMFS_COMPRESSION_* macros to build initial ramfs file. Since none of them is defined, resulting 'initramfs_data.cpio' file remains un-compressed. This patch updates the Makefile to use CONFIG_RD_* variables and adds support for LZ4 compression algorithm. Also updates the 'gen_initramfs_list.sh' script to check whether a selected compression command is accessible or not. And fall-back to default gzip(1) compression when it is not. Signed-off-by: P J P Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

gen_init_cpio: avoid NULL pointer dereference and rework env expanding

2013-11-13T03:09:12Z

getenv() may return NULL if given environment variable does not exist which leads to NULL dereference when calling strncat. Besides that, the environment variable name was copied to a temporary env_var buffer, but this copying can be avoided by simply using the input string. Lastly, the whole loop can be greatly simplified by using the snprintf function instead of the playing with strncat. By the way, the current implementation allows a recursive variable expansion, as in: $ echo 'out ${A} out ' | A='a ${B} a' B=b /tmp/a out a b a out I'm assuming this is just a side effect and not a conscious decision (especially as this may lead to infinite loop), but I didn't want to change this behaviour without consulting. If the current behaviour is deamed incorrect, I'll be happy to send a patch without recursive processing. Signed-off-by: Michal Nazarewicz Cc: Kees Cook Cc: Jiri Kosina Cc: Jesper Juhl Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds