initramfs: avoid static buffer for error message

The dynamic error message printed if CONFIG_RD_$ALG compression support
is missing needn't be propagated up to the caller via a static buffer.
Print

initramfs: avoid static buffer for error message

The dynamic error message printed if CONFIG_RD_$ALG compression support
is missing needn't be propagated up to the caller via a static buffer.
Print it immediately via pr_err() and set @message to a const string to
flag error.

Before:
text data bss dec hex filename
8006 1118 8 9132 23ac init/initramfs.o

After:
text data bss dec hex filename
7938 1022 8 8968 2308 init/initramfs.o

Signed-off-by: David Disseldorp <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

show more ...

initramfs: fix hardlink hash leak without TRAILER

Covered in Documentation/driver-api/early-userspace/buffer-format.rst ,
initramfs archives can carry an optional "TRAILER!!!" entry which serves
as

initramfs: fix hardlink hash leak without TRAILER

Covered in Documentation/driver-api/early-userspace/buffer-format.rst ,
initramfs archives can carry an optional "TRAILER!!!" entry which serves
as a boundary for collecting and associating hardlinks with matching
inode and major / minor device numbers.

Although optional, if hardlinks are found in an archive without a
subsequent "TRAILER!!!" entry then the hardlink state hash table is
leaked, e.g. unfixed kernel, with initramfs_test.c hunk applied only:
unreferenced object 0xffff9405408cc000 (size 8192):
comm "kunit_try_catch", pid 53, jiffies 4294892519
hex dump (first 32 bytes):
01 00 00 00 01 00 00 00 00 00 00 00 ff 81 00 00 ................
00 00 00 00 00 00 00 00 69 6e 69 74 72 61 6d 66 ........initramf
backtrace (crc a9fb0ee0):
[<0000000066739faa>] __kmalloc_cache_noprof+0x11d/0x250
[<00000000fc755219>] maybe_link.part.5+0xbc/0x120
[<000000000526a128>] do_name+0xce/0x2f0
[<00000000145c1048>] write_buffer+0x22/0x40
[<000000003f0b4f32>] unpack_to_rootfs+0xf9/0x2a0
[<00000000d6f7e5af>] initramfs_test_hardlink+0xe3/0x3f0
[<0000000014fde8d6>] kunit_try_run_case+0x5f/0x130
[<00000000dc9dafc5>] kunit_generic_run_threadfn_adapter+0x18/0x30
[<000000001076c239>] kthread+0xc8/0x100
[<00000000d939f1c1>] ret_from_fork+0x2b/0x40
[<00000000f848ad1a>] ret_from_fork_asm+0x1a/0x30

Fix this by calling free_hash() after initramfs buffer processing in
unpack_to_rootfs(). An extra hardlink_seen global is added as an
optimization to avoid walking the 32 entry hash array unnecessarily.
The expectation is that a "TRAILER!!!" entry will normally be present,
and initramfs hardlinks are uncommon.

There is one user facing side-effect of this fix: hardlinks can
currently be associated across built-in and external initramfs archives,
*if* the built-in initramfs archive lacks a "TRAILER!!!" terminator. I'd
consider this cross-archive association broken, but perhaps it's used.

Signed-off-by: David Disseldorp <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

show more ...

initramfs: reuse name_len for dir mtime tracking

We already have a nulterm-inclusive, checked name_len for the directory
name, so use that instead of calling strlen().

Signed-off-by: David Disseldo

initramfs: reuse name_len for dir mtime tracking

We already have a nulterm-inclusive, checked name_len for the directory
name, so use that instead of calling strlen().

Signed-off-by: David Disseldorp <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

show more ...

initramfs: allocate heap buffers together

header_buf, symlink_buf and name_buf all share the same lifecycle so
needn't be allocated / freed separately. This change leads to a minor
reduction in .tex

initramfs: allocate heap buffers together

header_buf, symlink_buf and name_buf all share the same lifecycle so
needn't be allocated / freed separately. This change leads to a minor
reduction in .text size:

before:
text data bss dec hex filename
7914 1110 8 9032 2348 init/initramfs.o

after:
text data bss dec hex filename
7854 1110 8 8972 230c init/initramfs.o

A previous iteration of this patch reused a single buffer instead of
three, given that buffer use is state-sequential (GotHeader, GotName,
GotSymlink). However, the slight decrease in heap use during early boot
isn't really worth the extra review complexity.

Link: https://lore.kernel.org/all/[email protected]/
Signed-off-by: David Disseldorp <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

show more ...

initramfs: avoid memcpy for hex header fields

newc/crc cpio headers contain a bunch of 8-character hexadecimal fields
which we convert via simple_strtoul(), following memcpy() into a
zero-terminated

initramfs: avoid memcpy for hex header fields

newc/crc cpio headers contain a bunch of 8-character hexadecimal fields
which we convert via simple_strtoul(), following memcpy() into a
zero-terminated stack buffer. The new simple_strntoul() helper allows us
to pass in max_chars=8 to avoid zero-termination and memcpy().

Signed-off-by: David Disseldorp <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

show more ...

init: add initramfs_internal.h

The new header only exports a single unpack function and a CPIO_HDRLEN
constant for future test use.

Signed-off-by: David Disseldorp <[email protected]>
Link: https://lor

init: add initramfs_internal.h

The new header only exports a single unpack function and a CPIO_HDRLEN
constant for future test use.

Signed-off-by: David Disseldorp <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

show more ...

initramfs: avoid filename buffer overrun

The initramfs filename field is defined in
Documentation/driver-api/early-userspace/buffer-format.rst as:

37 cpio_file := ALGN(4) + cpio_header + filename

initramfs: avoid filename buffer overrun

The initramfs filename field is defined in
Documentation/driver-api/early-userspace/buffer-format.rst as:

37 cpio_file := ALGN(4) + cpio_header + filename + "\0" + ALGN(4) + data
...
55 ============= ================== =========================
56 Field name Field size Meaning
57 ============= ================== =========================
...
70 c_namesize 8 bytes Length of filename, including final \0

When extracting an initramfs cpio archive, the kernel's do_name() path
handler assumes a zero-terminated path at @collected, passing it
directly to filp_open() / init_mkdir() / init_mknod().

If a specially crafted cpio entry carries a non-zero-terminated filename
and is followed by uninitialized memory, then a file may be created with
trailing characters that represent the uninitialized memory. The ability
to create an initramfs entry would imply already having full control of
the system, so the buffer overrun shouldn't be considered a security
vulnerability.

Append the output of the following bash script to an existing initramfs
and observe any created /initramfs_test_fname_overrunAA* path. E.g.
./reproducer.sh | gzip >> /myinitramfs

It's easiest to observe non-zero uninitialized memory when the output is
gzipped, as it'll overflow the heap allocated @out_buf in __gunzip(),
rather than the initrd_start+initrd_size block.

---- reproducer.sh ----
nilchar="A" # change to "\0" to properly zero terminate / pad
magic="070701"
ino=1
mode=$(( 0100777 ))
uid=0
gid=0
nlink=1
mtime=1
filesize=0
devmajor=0
devminor=1
rdevmajor=0
rdevminor=0
csum=0
fname="initramfs_test_fname_overrun"
namelen=$(( ${#fname} + 1 )) # plus one to account for terminator

printf "%s%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%s" \
$magic $ino $mode $uid $gid $nlink $mtime $filesize \
$devmajor $devminor $rdevmajor $rdevminor $namelen $csum $fname

termpadlen=$(( 1 + ((4 - ((110 + $namelen) & 3)) % 4) ))
printf "%.s${nilchar}" $(seq 1 $termpadlen)
---- reproducer.sh ----

Symlink filename fields handled in do_symlink() won't overrun past the
data segment, due to the explicit zero-termination of the symlink
target.

Fix filename buffer overrun by aborting the initramfs FSM if any cpio
entry doesn't carry a zero-terminator at the expected (name_len - 1)
offset.

Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2")
Signed-off-by: David Disseldorp <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

show more ...

initramfs,lsm: add a security hook to do_populate_rootfs()

This patch introduces a new hook to notify security system that the
content of initramfs has been unpacked into the rootfs.

Upon receiving

initramfs,lsm: add a security hook to do_populate_rootfs()

This patch introduces a new hook to notify security system that the
content of initramfs has been unpacked into the rootfs.

Upon receiving this notification, the security system can activate
a policy to allow only files that originated from the initramfs to
execute or load into kernel during the early stages of booting.

This approach is crucial for minimizing the attack surface by
ensuring that only trusted files from the initramfs are operational
in the critical boot phase.

Signed-off-by: Fan Wu <[email protected]>
[PM: subject line tweak]
Signed-off-by: Paul Moore <[email protected]>

show more ...

treewide: Use sysfs_bin_attr_simple_read() helper

Deduplicate ->read() callbacks of bin_attributes which are backed by a
simple buffer in memory:

Use the newly introduced sysfs_bin_attr_simple_read

treewide: Use sysfs_bin_attr_simple_read() helper

Deduplicate ->read() callbacks of bin_attributes which are backed by a
simple buffer in memory:

Use the newly introduced sysfs_bin_attr_simple_read() helper instead,
either by referencing it directly or by declaring such bin_attributes
with BIN_ATTR_SIMPLE_RO() or BIN_ATTR_SIMPLE_ADMIN_RO().

Aside from a reduction of LoC, this shaves off a few bytes from vmlinux
(304 bytes on an x86_64 allyesconfig).

No functional change intended.

Signed-off-by: Lukas Wunner <[email protected]>
Acked-by: Zhi Wang <[email protected]>
Acked-by: Michael Ellerman <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Acked-by: Ard Biesheuvel <[email protected]>
Link: https://lore.kernel.org/r/92ee0a0e83a5a3f3474845db6c8575297698933a.1712410202.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

init: open output files from cpio unpacking with O_LARGEFILE

If a member of a cpio archive for an initrd or initrams is larger than
2Gb, we'll eventually fail to write to that file when we get to th

init: open output files from cpio unpacking with O_LARGEFILE

If a member of a cpio archive for an initrd or initrams is larger than
2Gb, we'll eventually fail to write to that file when we get to that
limit, unless O_LARGEFILE is set.

The problem can be seen with this recipe, assuming that BLK_DEV_RAM
is not configured:

cd /tmp
dd if=/dev/zero of=BIGFILE bs=1048576 count=2200
echo BIGFILE | cpio -o -H newc -R root:root > initrd.img
kexec -l /boot/vmlinuz-$(uname -r) --initrd=initrd.img --reuse-cmdline
kexec -e

The console will show 'Initramfs unpacking failed: write error'. With
the patch, the error is gone.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: John Sperbeck <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

init: open /initrd.image with O_LARGEFILE

If initrd data is larger than 2Gb, we'll eventually fail to write to the
/initrd.image file when we hit that limit, unless O_LARGEFILE is set.

Link: https:

init: open /initrd.image with O_LARGEFILE

If initrd data is larger than 2Gb, we'll eventually fail to write to the
/initrd.image file when we hit that limit, unless O_LARGEFILE is set.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: John Sperbeck <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

crash: split crash dumping code out from kexec_core.c

Currently, KEXEC_CORE select CRASH_CORE automatically because crash codes
need be built in to avoid compiling error when building kexec code eve

crash: split crash dumping code out from kexec_core.c

Currently, KEXEC_CORE select CRASH_CORE automatically because crash codes
need be built in to avoid compiling error when building kexec code even
though the crash dumping functionality is not enabled. E.g
--------------------
CONFIG_CRASH_CORE=y
CONFIG_KEXEC_CORE=y
CONFIG_KEXEC=y
CONFIG_KEXEC_FILE=y
---------------------

After splitting out crashkernel reservation code and vmcoreinfo exporting
code, there's only crash related code left in kernel/crash_core.c. Now
move crash related codes from kexec_core.c to crash_core.c and only build it
in when CONFIG_CRASH_DUMP=y.

And also wrap up crash codes inside CONFIG_CRASH_DUMP ifdeffery scope,
or replace inappropriate CONFIG_KEXEC_CORE ifdef with CONFIG_CRASH_DUMP
ifdef in generic kernel files.

With these changes, crash_core codes are abstracted from kexec codes and
can be disabled at all if only kexec reboot feature is wanted.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Baoquan He <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Hari Bathini <[email protected]>
Cc: Pingfan Liu <[email protected]>
Cc: Klara Modin <[email protected]>
Cc: Michael Kelley <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Yang Li <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

init: flush async file closing

When unpacking the initramfs or when mounting block devices we need to
ensure that any delayed fput() finished to prevent spurious errors.
The init process can be a pr

init: flush async file closing

When unpacking the initramfs or when mounting block devices we need to
ensure that any delayed fput() finished to prevent spurious errors.
The init process can be a proper kernel thread or a user mode helper.
In the latter case PF_KTHREAD isn't set. So we need to do both
flush_delayed_work() and task_work_run().

Since we'll port block device opening and closing to regular file open
and closing we need to ensure the same as for the initramfs. So just
make that a little helper.

Tested-by: Marek Szyprowski <[email protected]>
Tested-by: Srikanth Aithal <[email protected]>
Link: https://lore.kernel.org/r/CA+G9fYttTwsbFuVq10igbSvP5xC6bf_XijM=mpUqrJV=uvUirQ@mail.gmail.com
Signed-off-by: Christian Brauner <[email protected]>

show more ...

initramfs: remove duplicate built-in __initramfs_start unpacking

If initrd_start cpio extraction fails, CONFIG_BLK_DEV_RAM triggers
fallback to initrd.image handling via populate_initrd_image().
The

initramfs: remove duplicate built-in __initramfs_start unpacking

If initrd_start cpio extraction fails, CONFIG_BLK_DEV_RAM triggers
fallback to initrd.image handling via populate_initrd_image().
The populate_initrd_image() call follows successful extraction of any
built-in cpio archive at __initramfs_start, but currently performs
built-in archive extraction a second time.

Prior to commit b2a74d5f9d446 ("initramfs: remove clean_rootfs"),
the second built-in initramfs unpack call was used to repopulate entries
removed by clean_rootfs(), but it's no longer necessary now the contents
of the previous extraction are retained.

Signed-off-by: David Disseldorp <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

show more ...

initramfs: Expose retained initrd as sysfs file

When the kernel command line option "retain_initrd" is set, we do not
free the initrd memory. However, we also don't expose it to anyone for
consumpti

initramfs: Expose retained initrd as sysfs file

When the kernel command line option "retain_initrd" is set, we do not
free the initrd memory. However, we also don't expose it to anyone for
consumption. That leaves us in a weird situation where the only user of
this feature is ppc64 and arm64 specific kexec tooling.

To make it more generally useful, this patch adds a kobject to the
firmware object that contains the initrd context when "retain_initrd"
is set. That way, we can access the initrd any time after boot from
user space and for example hand it into kexec as --initrd parameter
if we want to reboot the same initrd. Or inspect it directly locally.

With this patch applied, there is a new /sys/firmware/initrd file when
the kernel was booted with an initrd and "retain_initrd" command line
option is set.

Signed-off-by: Alexander Graf <[email protected]>
Tested-by: Bagas Sanjaya <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

mm: remove arguments of show_mem()

All callers of show_mem() pass 0 and NULL, so we can remove the two
arguments by directly calling __show_mem(0, NULL, MAX_NR_ZONES - 1) in
show_mem().

Link: https

mm: remove arguments of show_mem()

All callers of show_mem() pass 0 and NULL, so we can remove the two
arguments by directly calling __show_mem(0, NULL, MAX_NR_ZONES - 1) in
show_mem().

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kefeng Wang <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

init/initramfs: Fix argument forwarding to panic() in panic_show_mem()

Forwarding variadic argument lists can't be done by passing a va_list
to a function with signature foo(...) (as panic() has). I

init/initramfs: Fix argument forwarding to panic() in panic_show_mem()

Forwarding variadic argument lists can't be done by passing a va_list
to a function with signature foo(...) (as panic() has). It ends up
interpreting the va_list itself as a single argument instead of
iterating it. printf() happily accepts it of course, leading to corrupt
output.

Convert panic_show_mem() to a macro to allow forwarding the arguments.
The function is trivial enough that it's easier than trying to introduce
a vpanic() variant.

Signed-off-by: Benjamin Gray <[email protected]>
Reviewed-by: Andrew Donnellan <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

show more ...

initramfs: use kstrtobool() instead of strtobool()

strtobool() is the same as kstrtobool(). However, the latter is more used
within the kernel.

In order to remove strtobool() and slightly simplify

initramfs: use kstrtobool() instead of strtobool()

strtobool() is the same as kstrtobool(). However, the latter is more used
within the kernel.

In order to remove strtobool() and slightly simplify kstrtox.h, switch to
the other function name.

While at it, include the corresponding header file (<linux/kstrtox.h>)

Link: https://lkml.kernel.org/r/2597e80cb7059ec6ad63a01b77d7c944dcc99195.1673716768.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: David Disseldorp <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Martin Wilck <[email protected]>
Cc: wuchi <[email protected]>
Cc: XU pengfei <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

initramfs: remove unnecessary (void*) conversion

Remove unnecessary void* type casting.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: XU pengfei <xupen

initramfs: remove unnecessary (void*) conversion

Remove unnecessary void* type casting.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: XU pengfei <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: David Disseldorp <[email protected]>
Cc: "Eric W . Biederman" <[email protected]>
Cc: Martin Wilck <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: wuchi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

initramfs: mark my_inptr as __initdata

As my_inptr is only used in __init function unpack_to_rootfs(), mark it as
__initdata to allow it be freed after boot.

Link: https://lkml.kernel.org/r/2022082

initramfs: mark my_inptr as __initdata

As my_inptr is only used in __init function unpack_to_rootfs(), mark it as
__initdata to allow it be freed after boot.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: wuchi <[email protected]>
Reviewed-by: David Disseldorp <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Martin Wilck <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

initramfs: support cpio extraction with file checksums

Add support for extraction of checksum-enabled "070702" cpio archives,
specified in Documentation/driver-api/early-userspace/buffer-format.rst.

initramfs: support cpio extraction with file checksums

Add support for extraction of checksum-enabled "070702" cpio archives,
specified in Documentation/driver-api/early-userspace/buffer-format.rst.
Fail extraction if the calculated file data checksum doesn't match the
value carried in the header.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Disseldorp <[email protected]>
Suggested-by: Matthew Wilcox (Oracle) <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Martin Wilck <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

initramfs: add INITRAMFS_PRESERVE_MTIME Kconfig option

initramfs cpio mtime preservation, as implemented in commit 889d51a10712
("initramfs: add option to preserve mtime from initramfs cpio images")

initramfs: add INITRAMFS_PRESERVE_MTIME Kconfig option

initramfs cpio mtime preservation, as implemented in commit 889d51a10712
("initramfs: add option to preserve mtime from initramfs cpio images"),
uses a linked list to defer directory mtime processing until after all
other items in the cpio archive have been processed. This is done to
ensure that parent directory mtimes aren't overwritten via subsequent
child creation.

The lkml link below indicates that the mtime retention use case was for
embedded devices with applications running exclusively out of initramfs,
where the 32-bit mtime value provided a rough file version identifier.
Linux distributions which discard an extracted initramfs immediately after
the root filesystem has been mounted may want to avoid the unnecessary
overhead.

This change adds a new INITRAMFS_PRESERVE_MTIME Kconfig option, which can
be used to disable on-by-default mtime retention and in turn speed up
initramfs extraction, particularly for cpio archives with large directory
counts.

Benchmarks with a one million directory cpio archive extracted 20 times
demonstrated:
mean extraction time (s) std dev
INITRAMFS_PRESERVE_MTIME=y 3.808 0.006
INITRAMFS_PRESERVE_MTIME unset 3.056 0.004

The above extraction times were measured using ftrace (initcall_finish -
initcall_start) values for populate_rootfs() with initramfs_async
disabled.

[[email protected]: rebase atop dir_entry.name flexible array member and drop separate initramfs_mtime.h header]
Link: https://lkml.org/lkml/2008/9/3/424
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Disseldorp <[email protected]>
Reviewed-by: Martin Wilck <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

initramfs: make dir_entry.name a flexible array member

dir_entry.name is currently allocated via a separate kstrdup(). Change it
to a flexible array member and allocate it along with struct dir_ent

initramfs: make dir_entry.name a flexible array member

dir_entry.name is currently allocated via a separate kstrdup(). Change it
to a flexible array member and allocate it along with struct dir_entry.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Disseldorp <[email protected]>
Acked-by: Christian Brauner <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Martin Wilck <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

initramfs: refactor do_header() cpio magic checks

Patch series "initramfs: "crc" cpio format and INITRAMFS_PRESERVE_MTIME", v7.

This patchset does some minor initramfs refactoring and allows cpio e

initramfs: refactor do_header() cpio magic checks

Patch series "initramfs: "crc" cpio format and INITRAMFS_PRESERVE_MTIME", v7.

This patchset does some minor initramfs refactoring and allows cpio entry
mtime preservation to be disabled via a new Kconfig
INITRAMFS_PRESERVE_MTIME option.

Patches 4/6 to 6/6 implement support for creation and extraction of "crc"
cpio archives, which carry file data checksums. Basic tests for this
functionality can be found at https://github.com/rapido-linux/rapido/pull/163


This patch (of 6):

do_header() is called for each cpio entry and fails if the first six bytes
don't match "newc" magic. The magic check includes a special case error
message if POSIX.1 ASCII (cpio -H odc) magic is detected. This special
case POSIX.1 check can be nested under the "newc" mismatch code path to
avoid calling memcmp() twice in a non-error case.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Disseldorp <[email protected]>
Reviewed-by: Martin Wilck <[email protected]>
Acked-by: Christian Brauner <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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init: Deal with the init process being a user mode process

It is silly for user_mode_thread to leave PF_KTHREAD set
on the resulting task. Update the init process so that
it does not care if PF_KTH

init: Deal with the init process being a user mode process

It is silly for user_mode_thread to leave PF_KTHREAD set
on the resulting task. Update the init process so that
it does not care if PF_KTHREAD is set or not.

Ensure do_populate_rootfs flushes all delayed fput work by calling
task_work_run. In the rare instance that async_schedule_domain calls
do_populate_rootfs synchronously it is possible do_populate_rootfs
will be called directly from the init process. At which point fput
will call "task_work_add(current, ..., TWA_RESUME)". The files on the
initramfs need to be completely put before we attempt to exec them
(which is before the code enters userspace). So call task_work_run
just in case there are any pending fput operations.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: "Eric W. Biederman" <[email protected]>

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