Avoid repetition of long variables.

No functional change intended.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>

Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention without any functional
difference. In fact, $(obj) and $(src) are exactly the same, as defined
in scripts/Makefile.build:

    src := $(obj)

When the kernel is built in a separate output directory, $(src) does
not accurately reflect the source directory location. While Kbuild
resolves this discrepancy by specifying VPATH=$(srctree) to search for
source files, it does not cover all cases. For example, when adding a
header search path for local headers, -I$(srctree)/$(src) is typically
passed to the compiler.

This introduces inconsistency between upstream and downstream Makefiles
because $(src) is used instead of $(srctree)/$(src) for the latter.

To address this inconsistency, this commit changes the semantics of
$(src) so that it always points to the directory in the source tree.

Going forward, the variables used in Makefiles will have the following
meanings:

  $(obj)     - directory in the object tree
  $(src)     - directory in the source tree  (changed by this commit)
  $(objtree) - the top of the kernel object tree
  $(srctree) - the top of the kernel source tree

Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced
with $(src).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

Currently gen_init_cpio -d <timestamp> is applied to symlinks,
directories and special files. These files are created by
gen_init_cpio from their description. Without <timestamp> option
current time(NULL) is used. And regular files that go in initramfs
are created before cpio generation, so their mtime(s) are preserved.

This is usually not an issue as reproducible builds should rebuild
everything in the distribution, including binaries, configs and whatever
other regular files may find their way into kernel's initramfs.

On the other hand, gen_initramfs.sh usage claims:
>	-d <date>      Use date for all file mtime values

Ar Arista initramfs files are managed with version control system
that preserves mtime. Those are configs, boot parameters, init scripts,
version files, platform-specific files, probably some others, too.

While it's certainly possible to work this around by copying the file
into temp directory and adjusting mtime prior to gen_init_cpio call,
I don't see why it needs workarounds.

The intended user of -d <date> option is the one that needs to create
a reproducible build, see commit a8b8017c ("initramfs: Use
KBUILD_BUILD_TIMESTAMP for generated entries"). If a user wants
the build reproduction, they use -d <date>, which can be set on all
types of files, without surprising exceptions and workarounds.
Let's KISS here and just apply the time that user specified
with -d option.

Based-on-a-patch-by: Baptiste Covolato <baptiste@arista.com>
Link: https://lore.kernel.org/lkml/20181025215133.20138-1-baptiste@arista.com/


Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Use "Its" or "its" for possessive instead of "it's" (contraction
for "it is").

Link: https://lkml.kernel.org/r/20231210053429.23146-1-rdunlap@infradead.org


Fixes: db2aa7fd ("initramfs: allow again choice of the embedded initram compression algorithm")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Acked-by: "Francisco Blas Izquierdo Riera (klondike)" <klondike@klondike.es>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The Itanium architecture is obsolete, and an informal survey [0] reveals
that any residual use of Itanium hardware in production is mostly HP-UX
or OpenVMS based. The use of Linux on Itanium appears to be limited to
enthusiasts that occasionally boot a fresh Linux kernel to see whether
things are still working as intended, and perhaps to churn out some
distro packages that are rarely used in practice.

None of the original companies behind Itanium still produce or support
any hardware or software for the architecture, and it is listed as
'Orphaned' in the MAINTAINERS file, as apparently, none of the engineers
that contributed on behalf of those companies (nor anyone else, for that
matter) have been willing to support or maintain the architecture
upstream or even be responsible for applying the odd fix. The Intel
firmware team removed all IA-64 support from the Tianocore/EDK2
reference implementation of EFI in 2018. (Itanium is the original
architecture for which EFI was developed, and the way Linux supports it
deviates significantly from other architectures.) Some distros, such as
Debian and Gentoo, still maintain [unofficial] ia64 ports, but many have
dropped support years ago.

While the argument is being made [1] that there is a 'for the common
good' angle to being able to build and run existing projects such as the
Grid Community Toolkit [2] on Itanium for interoperability testing, the
fact remains that none of those projects are known to be deployed on
Linux/ia64, and very few people actually have access to such a system in
the first place. Even if there were ways imaginable in which Linux/ia64
could be put to good use today, what matters is whether anyone is
actually doing that, and this does not appear to be the case.

There are no emulators widely available, and so boot testing Itanium is
generally infeasible for ordinary contributors. GCC still supports IA-64
but its compile farm [3] no longer has any IA-64 machines. GLIBC would
like to get rid of IA-64 [4] too because it would permit some overdue
code cleanups. In summary, the benefits to the ecosystem of having IA-64
be part of it are mostly theoretical, whereas the maintenance overhead
of keeping it supported is real.

So let's rip off the band aid, and remove the IA-64 arch code entirely.
This follows the timeline proposed by the Debian/ia64 maintainer [5],
which removes support in a controlled manner, leaving IA-64 in a known
good state in the most recent LTS release. Other projects will follow
once the kernel support is removed.

[0] https://lore.kernel.org/all/CAMj1kXFCMh_578jniKpUtx_j8ByHnt=s7S+yQ+vGbKt9ud7+kQ@mail.gmail.com/
[1] https://lore.kernel.org/all/0075883c-7c51-00f5-2c2d-5119c1820410@web.de/
[2] https://gridcf.org/gct-docs/latest/index.html
[3] https://cfarm.tetaneutral.net/machines/list/
[4] https://lore.kernel.org/all/87bkiilpc4.fsf@mid.deneb.enyo.de/
[5] https://lore.kernel.org/all/ff58a3e76e5102c94bb5946d99187b358def688a.camel@physik.fu-berlin.de/



Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

gen_initramfs.sh has an internal dependency on KBUILD_BUILD_TIMESTAMP
for generating file mtimes that is not exposed to make, so changing
KBUILD_BUILD_TIMESTAMP will not trigger a rebuild of the archive.

Declare the mtime date as a new parameter to gen_initramfs.sh to encode
KBUILD_BUILD_TIMESTAMP in the shell command, thereby making make aware
of the dependency.

It will rebuild if KBUILD_BUILD_TIMESTAMP changes or is newly set/unset.
It will _not_ rebuild if KBUILD_BUILD_TIMESTAMP is unset before and
after. This should be fine for anyone who doesn't care about setting
specific build times in the first place.

Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Tested-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Similar to commit 4c9d410f ("initramfs: Check timestamp to prevent
broken cpio archive"), except asserts that the timestamp is
non-negative. This can happen when the KBUILD_BUILD_TIMESTAMP is a value
before UNIX epoch, which may be set when making reproducible builds that
don't want to look like they use a valid date.

While support for dates before 1970 might not be supported, this is more
about preventing undetected CPIO corruption. The printf's use a minimum
length format specifier, and will happily make the field longer than 8
characters if they need to.

Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Tested-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

The file variable is assigned first, it does not need to be initialized.

Link: https://lkml.kernel.org/r/20220919014406.3242-1-zeming@nfschina.com


Signed-off-by: Li zeming <zeming@nfschina.com>
Cc: Li zeming <zeming@nfschina.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

asm/stat.h is currently excluded from the UAPI compile-test for
ARCH=sparc because of the errors like follows:

  In file included from <command-line>:
  ./usr/include/asm/stat.h:11:2: error: unknown type name 'ino_t'
     11 |  ino_t   st_ino;
        |  ^~~~~
    HDRTEST usr/include/asm/param.h
  ./usr/include/asm/stat.h:12:2: error: unknown type name 'mode_t'
     12 |  mode_t  st_mode;
        |  ^~~~~~
  ./usr/include/asm/stat.h:14:2: error: unknown type name 'uid_t'
     14 |  uid_t   st_uid;
        |  ^~~~~
  ./usr/include/asm/stat.h:15:2: error: unknown type name 'gid_t'
     15 |  gid_t   st_gid;
        |  ^~~~~

The errors can be fixed by prefixing the types with __kernel_.

Then, remove the no-header-test entry from user/include/Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>

asm/stat.h is currently excluded from the UAPI compile-test for
ARCH=powerpc because of the errors like follows:

    HDRTEST usr/include/asm/stat.h
  In file included from <command-line>:32:
  ./usr/include/asm/stat.h:32:2: error: unknown type name 'ino_t'
     32 |  ino_t  st_ino;
        |  ^~~~~
  ./usr/include/asm/stat.h:35:2: error: unknown type name 'mode_t'
     35 |  mode_t  st_mode;
        |  ^~~~~~
  ./usr/include/asm/stat.h:40:2: error: unknown type name 'uid_t'
     40 |  uid_t  st_uid;
        |  ^~~~~
  ./usr/include/asm/stat.h:41:2: error: unknown type name 'gid_t'
     41 |  gid_t  st_gid;
        |  ^~~~~

The errors can be fixed by prefixing the types with __kernel_.

Then, remove the no-header-test entry from user/include/Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>

asm/stat.h is currently excluded from the UAPI compile-test for
ARCH=mips because of the errors like follows:

    HDRTEST usr/include/asm/stat.h
  In file included from <command-line>:32:
  ./usr/include/asm/stat.h:22:2: error: unknown type name 'ino_t'
     22 |  ino_t  st_ino;
        |  ^~~~~
  ./usr/include/asm/stat.h:23:2: error: unknown type name 'mode_t'
     23 |  mode_t  st_mode;
        |  ^~~~~~
  ./usr/include/asm/stat.h:25:2: error: unknown type name 'uid_t'
     25 |  uid_t  st_uid;
        |  ^~~~~
  ./usr/include/asm/stat.h:26:2: error: unknown type name 'gid_t'
     26 |  gid_t  st_gid;
        |  ^~~~~
  ./usr/include/asm/stat.h:58:2: error: unknown type name 'mode_t'
     58 |  mode_t  st_mode;
        |  ^~~~~~
  ./usr/include/asm/stat.h:61:2: error: unknown type name 'uid_t'
     61 |  uid_t  st_uid;
        |  ^~~~~
  ./usr/include/asm/stat.h:62:2: error: unknown type name 'gid_t'
     62 |  gid_t  st_gid;
        |  ^~~~~

The errors can be fixed by prefixing the types with __kernel_.

Then, remove the no-header-test entry from user/include/Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>

I can compile this for ARCH=riscv with CONFIG_UAPI_HEADER_TEST=y.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>

Some UAPI headers included <stdlib.h>, like this:

  #ifndef __KERNEL__
  #include <stdlib.h>
  #endif

As it turned out, they just included it for no good reason.

After some fixes, now I can compile-test UAPI headers
(CONFIG_UAPI_HEADER_TEST=y) without including <stdlib.h> from the
system header search paths.

To avoid somebody getting it back again, this commit adds the dummy
header, usr/dummy-include/stdlib.h

I added $(srctree)/usr/dummy-include to the header search paths.
Because it is searched before the system directories, if someone
tries to include <stdlib.h>, they will see the error message.

While I am here, I also replaced $(objtree)/usr/include with $(obj),
but it has no functional change.

If we can make kernel headers self-contained (that is, none of exported
kernel headers includes system headers), we will be able to add the
-nostdinc flag, but that is much far from where we stand now.

As a realistic solution, we can ban header inclusion individually by
putting a dummy header into usr/dummy-include/.

Currently, no header include <stdbool.h>. I put it as well before somebody
attempts to use it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/driver-api/early-userspace/buffer-format.rst includes the
specification for checksum-enabled cpio archives.  Implement support for
this format in gen_init_cpio via a new '-c' parameter.

Link: https://lkml.kernel.org/r/20220404093429.27570-6-ddiss@suse.de


Signed-off-by: David Disseldorp <ddiss@suse.de>
Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Martin Wilck <mwilck@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

When processing a "file" entry, gen_init_cpio attempts to allocate a
buffer large enough to stage the entire contents of the source file.  It
then attempts to fill the buffer via a single read() call and subsequently
writes out the entire buffer length, without checking that read() returned
the full length, potentially writing uninitialized buffer memory.

Fix this by breaking up file I/O into 64k chunks and only writing the
length returned by the prior read() call.

Link: https://lkml.kernel.org/r/20220404093429.27570-5-ddiss@suse.de


Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The UAPI header tests are checking that the generated headers do not
have syntax errors. There's no need to run the rest of the compilation
pipeline after semantic analysis has run. Replace -S -o /dev/null with
-fsyntax-only.

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

When you compile-test UAPI headers (CONFIG_UAPI_HEADER_TEST=y) with
Clang, they are currently compiled for the host target (likely x86_64)
regardless of the given ARCH=.

In fact, some exported headers include libc headers. For example,
include/uapi/linux/agpgart.h includes <stdlib.h> after being exported.
The header search paths should match to the target we are compiling
them for.

Pick up the --target triple from KBUILD_CFLAGS in the same ways as
commit 7f58b487 ("kbuild: make Clang build userprogs for target
architecture").

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

extra-y is not run for 'make modules'. The header compile test should
be executed irrespective of the build target. always-y is a better fit.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

linux/reiserfs_xattr.h is currently excluded from the UAPI compile-test
because of the error like follows:

    HDRTEST usr/include/linux/reiserfs_xattr.h
  In file included from <command-line>:
  ./usr/include/linux/reiserfs_xattr.h:22:9: error: unknown type name ‘size_t’
     22 |         size_t length;
        |         ^~~~~~

The error can be fixed by replacing size_t with __kernel_size_t.

Then, remove the no-header-test entry from user/include/Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

linux/kexec.h is currently excluded from the UAPI compile-test because
of the errors like follows:

    HDRTEST usr/include/linux/kexec.h
  In file included from <command-line>:
  ./usr/include/linux/kexec.h:56:9: error: unknown type name ‘size_t’
     56 |         size_t bufsz;
        |         ^~~~~~
  ./usr/include/linux/kexec.h:58:9: error: unknown type name ‘size_t’
     58 |         size_t memsz;
        |         ^~~~~~

The errors can be fixed by replacing size_t with __kernel_size_t.

Then, remove the no-header-test entry from user/include/Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

linux/fsmap.h is currently excluded from the UAPI compile-test because
of the error like follows:

    HDRTEST usr/include/linux/fsmap.h
  In file included from <command-line>:
  ./usr/include/linux/fsmap.h:72:19: error: unknown type name ‘size_t’
     72 | static __inline__ size_t
        |                   ^~~~~~

The error can be fixed by replacing size_t with __kernel_size_t.

Then, remove the no-header-test entry from user/include/Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

linux/android/binder.h and linux/android/binderfs.h are currently
excluded from the UAPI compile-test because of the errors like follows:

    HDRTEST usr/include/linux/android/binder.h
  In file included from <command-line>:
  ./usr/include/linux/android/binder.h:291:9: error: unknown type name ‘pid_t’
    291 |         pid_t           sender_pid;
        |         ^~~~~
  ./usr/include/linux/android/binder.h:292:9: error: unknown type name ‘uid_t’
    292 |         uid_t           sender_euid;
        |         ^~~~~

The errors can be fixed by replacing {pid,uid}_t with __kernel_{pid,uid}_t.

Then, remove the no-header-test entries from user/include/Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

asm/shmbuf.h is currently excluded from the UAPI compile-test because of
the errors like follows:

    HDRTEST usr/include/asm/shmbuf.h
  In file included from ./usr/include/asm/shmbuf.h:6,
                   from <command-line>:
  ./usr/include/asm-generic/shmbuf.h:26:33: error: field ‘shm_perm’ has incomplete type
     26 |         struct ipc64_perm       shm_perm;       /* operation perms */
        |                                 ^~~~~~~~
  ./usr/include/asm-generic/shmbuf.h:27:9: error: unknown type name ‘size_t’
     27 |         size_t                  shm_segsz;      /* size of segment (bytes) */
        |         ^~~~~~
  ./usr/include/asm-generic/shmbuf.h:40:9: error: unknown type name ‘__kernel_pid_t’
     40 |         __kernel_pid_t          shm_cpid;       /* pid of creator */
        |         ^~~~~~~~~~~~~~
  ./usr/include/asm-generic/shmbuf.h:41:9: error: unknown type name ‘__kernel_pid_t’
     41 |         __kernel_pid_t          shm_lpid;       /* pid of last operator */
        |         ^~~~~~~~~~~~~~

The errors can be fixed by replacing size_t with __kernel_size_t and by
including proper headers.

Then, remove the no-header-test entry from user/include/Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

linux/signal.h and asm/signal.h are currently excluded from the UAPI
compile-test because of the errors like follows:

    HDRTEST usr/include/asm/signal.h
  In file included from <command-line>:
  ./usr/include/asm/signal.h:103:9: error: unknown type name ‘size_t’
    103 |         size_t ss_size;
        |         ^~~~~~

The errors can be fixed by replacing size_t with __kernel_size_t.

Then, remove the no-header-test entries from user/include/Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Allow additional arguments be passed to userprogs compilation.
Reproducible clang builds need to provide a sysroot and gcc path to
ensure the same toolchain is used across hosts. KCFLAGS is not currently
used for any user programs compilation, so add new USERCFLAGS and
USERLDFLAGS which serves similar purpose as HOSTCFLAGS/HOSTLDFLAGS.

Clang might detect GCC installation on hosts which have it installed
to a default location in /. With addition of these environment
variables, you can specify flags such as:

$ make USERCFLAGS=--sysroot=/path/to/sysroot

This can also be used to specify different sysroots such as musl or
bionic which may be installed on the host in paths that the compiler
may not search by default.

Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

cmd_copy and cmd_shipped have similar functionality. The difference is
that cmd_copy uses 'cp' while cmd_shipped 'cat'.

Unify them into cmd_copy because this macro name is more intuitive.

Going forward, cmd_copy will use 'cat' to avoid the permission issue.
I also thought of 'cp --no-preserve=mode' but this option is not
mentioned in the POSIX spec [1], so I am keeping the 'cat' command.

[1]: https://pubs.opengroup.org/onlinepubs/009695299/utilities/cp.html


Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@collabora.com>

The file now rightfully throws up a big warning that it should never be
included, so remove it from the header_check test.

Fixes: f23653fe ("tty: Partially revert the removal of the Cyclades public API")
Cc: stable <stable@vger.kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: "Maciej W. Rozycki" <macro@embecosm.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/20220127073304.42399-1-gregkh@linuxfoundation.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

As linux/nfc.h userspace compilation was finally fixed by commits
79b69a83 ("nfc: uapi: use kernel size_t to fix user-space builds")
and 7175f02c ("uapi: fix linux/nfc.h userspace compilation errors"),
there is no need to keep the compile-test exception for it in
usr/include/Makefile.

Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

GZIP-compressed files end with 4 byte data that represents the size
of the original input. The decompressors (the self-extracting kernel)
exploit it to know the vmlinux size beforehand. To mimic the GZIP's
trailer, Kbuild provides cmd_{bzip2,lzma,lzo,lz4,xzkern,zstd22}.
Unfortunately these macros are used everywhere despite the appended
size data is only useful for the decompressors.

There is no guarantee that such hand-crafted trailers are safely ignored.
In fact, the kernel refuses compressed initramdfs with the garbage data.
That is why usr/Makefile overrides size_append to make it no-op.

To limit the use of such broken compressed files, this commit renames
the existing macros as follows:

  cmd_bzip2   --> cmd_bzip2_with_size
  cmd_lzma    --> cmd_lzma_with_size
  cmd_lzo     --> cmd_lzo_with_size
  cmd_lz4     --> cmd_lz4_with_size
  cmd_xzkern  --> cmd_xzkern_with_size
  cmd_zstd22  --> cmd_zstd22_with_size

To keep the decompressors working, I updated the following Makefiles
accordingly:

  arch/arm/boot/compressed/Makefile
  arch/h8300/boot/compressed/Makefile
  arch/mips/boot/compressed/Makefile
  arch/parisc/boot/compressed/Makefile
  arch/s390/boot/compressed/Makefile
  arch/sh/boot/compressed/Makefile
  arch/x86/boot/compressed/Makefile

I reused the current macro names for the normal usecases; they produce
the compressed data in the proper format.

I did not touch the following:

  arch/arc/boot/Makefile
  arch/arm64/boot/Makefile
  arch/csky/boot/Makefile
  arch/mips/boot/Makefile
  arch/riscv/boot/Makefile
  arch/sh/boot/Makefile
  kernel/Makefile

This means those Makefiles will stop appending the size data.

I dropped the 'override size_append' hack from usr/Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>

The previous commit fixed up all shell scripts to not include
include/config/auto.conf.

Now that include/config/auto.conf is only included by Makefiles,
we can change it into a more Make-friendly form.

Previously, Kconfig output string values enclosed with double-quotes
(both in the .config and include/config/auto.conf):

    CONFIG_X="foo bar"

Unlike shell, Make handles double-quotes (and single-quotes as well)
verbatim. We must rip them off when used.

There are some patterns:

  [1] $(patsubst "%",%,$(CONFIG_X))
  [2] $(CONFIG_X:"%"=%)
  [3] $(subst ",,$(CONFIG_X))
  [4] $(shell echo $(CONFIG_X))

These are not only ugly, but also fragile.

[1] and [2] do not work if the value contains spaces, like
   CONFIG_X=" foo bar "

[3] does not work correctly if the value contains double-quotes like
   CONFIG_X="foo\"bar"

[4] seems to work better, but has a cost of forking a process.

Anyway, quoted strings were always PITA for our Makefiles.

This commit changes Kconfig to stop quoting in include/config/auto.conf.

These are the string type symbols referenced in Makefiles or scripts:

    ACPI_CUSTOM_DSDT_FILE
    ARC_BUILTIN_DTB_NAME
    ARC_TUNE_MCPU
    BUILTIN_DTB_SOURCE
    CC_IMPLICIT_FALLTHROUGH
    CC_VERSION_TEXT
    CFG80211_EXTRA_REGDB_KEYDIR
    EXTRA_FIRMWARE
    EXTRA_FIRMWARE_DIR
    EXTRA_TARGETS
    H8300_BUILTIN_DTB
    INITRAMFS_SOURCE
    LOCALVERSION
    MODULE_SIG_HASH
    MODULE_SIG_KEY
    NDS32_BUILTIN_DTB
    NIOS2_DTB_SOURCE
    OPENRISC_BUILTIN_DTB
    SOC_CANAAN_K210_DTB_SOURCE
    SYSTEM_BLACKLIST_HASH_LIST
    SYSTEM_REVOCATION_KEYS
    SYSTEM_TRUSTED_KEYS
    TARGET_CPU
    UNUSED_KSYMS_WHITELIST
    XILINX_MICROBLAZE0_FAMILY
    XILINX_MICROBLAZE0_HW_VER
    XTENSA_VARIANT_NAME

I checked them one by one, and fixed up the code where necessary.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This script is only used by usr/include/Makefile. Make it local to
the directory.

Update the comment in include/uapi/linux/soundcard.h because
'make headers_check' is no longer functional.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Cpio format reserves 8 bytes for an ASCII representation of a time_t timestamp.
While 2106-02-07 06:28:15 UTC (time_t = 0xffffffff) is still some years in the
future, a poorly chosen date string for KBUILD_BUILD_TIMESTAMP, converted into
seconds since the epoch, might lead to exceeded cpio timestamp limits that
result in a broken cpio archive.  Add timestamp checks to prevent overrun of
the 8-byte cpio header field.

My colleague Thomas Kühnel discovered the behaviour, when we accidentally fed
SOURCE_DATE_EPOCH to KBUILD_BUILD_TIMESTAMP as is: some timestamps (e.g.
1607420928 = 2021-12-08 9:48:48 UTC) will be interpreted by `date` as a valid
date specification of science fictional times (here: year 160742).  Even though
this is bad input for KBUILD_BUILD_TIMESTAMP, it should not break the initramfs
cpio format.

Signed-off-by: Nicolas Schier <nicolas@fjasle.eu>
Cc: Thomas Kühnel <thomas.kuehnel@avm.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Add 'const' to constant arrays. I also added missing 'static'.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

The pattern prefixed with '/' matches files in the same directory,
but not ones in sub-directories.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Andra Paraschiv <andraprs@amazon.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Gabriel Krisman Bertazi <krisman@collabora.com>

LANG gives a weak default to each LC_* in case it is not explicitly
defined. LC_ALL, if set, overrides all other LC_* variables.

  LANG  <  LC_CTYPE, LC_COLLATE, LC_MONETARY, LC_NUMERIC, ...  <  LC_ALL

This is why documentation such as [1] suggests to set LC_ALL in build
scripts to get the deterministic result.

LANG=C is not strong enough to override LC_* that may be set by end
users.

[1]: https://reproducible-builds.org/docs/locales/



Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Matthias Maennich <maennich@google.com>
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net> (mptcp)
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The current .gitignore intends to ignore everything under usr/include/
except .gitignore and Makefile.

A cleaner solution is to use a pattern suffixed with '/', which matches
only directories. It works well here because all the exported headers
are located in sub-directories, like <linux/*.h>, <asm/*.h>.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Commit be1859bd ("initramfs: remove redundant dependency on
BLK_DEV_INITRD") removed all redundant dependencies on BLK_DEV_INITRD,
but the recent addition of zstd support introduced a new one.

Fixes: a30d8a39 ("usr: Add support for zstd compressed initramfs")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Perfmon support (used by oprofile earlier) was removed by commit
ecf5b72d ("ia64: Remove perfmon") earlier, but it missed few files
to remove/update.

Clean it up.

Suggested-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Robert Richter <rric@kernel.org>
Acked-by: William Cohen <wcohen@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Thomas Gleixner <tglx@linutronix.de>

Nick Terrell authored 4 years ago and Ingo Molnar committed 4 years ago

- Add support for a zstd compressed initramfs.

- Add compression for compressing built-in initramfs with zstd.

I have tested this patch by boot testing with buildroot and QEMU.
Specifically, I booted the kernel with both a zstd and gzip compressed
initramfs, both built into the kernel and separate. I ensured that the
correct compression algorithm was used. I tested on arm, aarch64, i386,
and x86_64.

This patch has been tested in production on aarch64 and x86_64 devices.

Additionally, I have performance measurements from internal use in
production. On an aarch64 device we saw 19 second boot time improvement
from switching from lzma to zstd (27 seconds to 8 seconds). On an x86_64
device we saw a 9 second boot time reduction from switching from xz to
zstd.

Signed-off-by: Nick Terrell <terrelln@fb.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200730190841.2071656-5-nickrterrell@gmail.com

It's unusable from userland - it uses elf_gregset_t, which is not
provided by exported headers.  glibc has it in sys/procfs.h, but
the same file defines struct elf_prstatus, so linux/elfcore.h can't
be included once sys/procfs.h has been pulled.  Same goes for uclibc
and dietlibc simply doesn't have elf_gregset_t defined anywhere.

IOW, no userland source is including that thing.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>