init/modpost: conditionally check section mismatch to __meminit*

This reverts commit eb8f689046b8 ("Use separate sections for __dev/
_cpu/__mem code/data").

Check section mismatch to __meminit* onl

init/modpost: conditionally check section mismatch to __meminit*

This reverts commit eb8f689046b8 ("Use separate sections for __dev/
_cpu/__mem code/data").

Check section mismatch to __meminit* only when CONFIG_MEMORY_HOTPLUG=n.

With this change, the linker script and modpost become simpler, and we
can get rid of the __ref annotations from the memory hotplug code.

[[email protected]: remove MEM_KEEP from arch/powerpc/kernel/vmlinux.lds.S]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Masahiro Yamada <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
Reviewed-by: Wei Yang <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

init: remove unused __MEMINIT* macros

These macros are not used anywhere.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Masahiro Yamada <masahiroy@ker

init: remove unused __MEMINIT* macros

These macros are not used anywhere.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Masahiro Yamada <[email protected]>
Reviewed-by: Wei Yang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

init: Declare rodata_enabled and mark_rodata_ro() at all time

Declaring rodata_enabled and mark_rodata_ro() at all time
helps removing related #ifdefery in C files.

Signed-off-by: Christophe Leroy

init: Declare rodata_enabled and mark_rodata_ro() at all time

Declaring rodata_enabled and mark_rodata_ro() at all time
helps removing related #ifdefery in C files.

Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>

show more ...

init: move THIS_MODULE from <linux/export.h> to <linux/init.h>

Commit f50169324df4 ("module.h: split out the EXPORT_SYMBOL into
export.h") appropriately separated EXPORT_SYMBOL into <linux/export.h>

init: move THIS_MODULE from <linux/export.h> to <linux/init.h>

Commit f50169324df4 ("module.h: split out the EXPORT_SYMBOL into
export.h") appropriately separated EXPORT_SYMBOL into <linux/export.h>
because modules and EXPORT_SYMBOL are orthogonal; modules are symbol
consumers, while EXPORT_SYMBOL are used by symbol providers, which
may not be necessarily a module.

However, that commit also relocated THIS_MODULE. As explained in the
commit description, the intention was to define THIS_MODULE in a
lightweight header, but I do not believe <linux/export.h> was the
best location because EXPORT_SYMBOL and THIS_MODULE are unrelated.

Move it to another lightweight header, <linux/init.h>. The reason for
choosing <linux/init.h> is to make <linux/moduleparam.h> self-contained
without relying on <linux/linkage.h> incorrectly including
<linux/export.h>.

With this adjustment, the role of <linux/export.h> becomes clearer as
it only defines EXPORT_SYMBOL.

Signed-off-by: Masahiro Yamada <[email protected]>
Reviewed-by: Luis Chamberlain <[email protected]>

show more ...

linux/init: remove __memexit* annotations

We have never used __memexit, __memexitdata, or __memexitconst.

These were unneeded.

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

linux/init: remove __memexit* annotations

We have never used __memexit, __memexitdata, or __memexitconst.

These were unneeded.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>

show more ...

x86/mem_encrypt: Remove stale mem_encrypt_init() declaration

The memory encryption initialization logic was moved from init/main.c
into arch_cpu_finalize_init() in commit 439e17576eb4 ("init, x86: M

x86/mem_encrypt: Remove stale mem_encrypt_init() declaration

The memory encryption initialization logic was moved from init/main.c
into arch_cpu_finalize_init() in commit 439e17576eb4 ("init, x86: Move
mem_encrypt_init() into arch_cpu_finalize_init()"), but a stale
declaration for the init function was left in <linux/init.h>.

And didn't cause any problems if you had X86_MEM_ENCRYPT enabled, which
apparently everybody involved did have. See also commit 0a9567ac5e6a
("x86/mem_encrypt: Unbreak the AMD_MEM_ENCRYPT=n build") in this whole
sad saga of conflicting declarations for different situations.

Reported-by: Matthew Wilcox <[email protected]>
Fixes: 439e17576eb4 init, x86: Move mem_encrypt_init() into arch_cpu_finalize_init()
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

init: consolidate prototypes in linux/init.h

The init/main.c file contains some extern declarations for functions
defined in architecture code, and it defines some other functions that are
called fr

init: consolidate prototypes in linux/init.h

The init/main.c file contains some extern declarations for functions
defined in architecture code, and it defines some other functions that are
called from architecture code with a custom prototype. Both of those
result in warnings with 'make W=1':

init/calibrate.c:261:37: error: no previous prototype for 'calibrate_delay_is_known' [-Werror=missing-prototypes]
init/main.c:790:20: error: no previous prototype for 'mem_encrypt_init' [-Werror=missing-prototypes]
init/main.c:792:20: error: no previous prototype for 'poking_init' [-Werror=missing-prototypes]
arch/arm64/kernel/irq.c:122:13: error: no previous prototype for 'init_IRQ' [-Werror=missing-prototypes]
arch/arm64/kernel/time.c:55:13: error: no previous prototype for 'time_init' [-Werror=missing-prototypes]
arch/x86/kernel/process.c:935:13: error: no previous prototype for 'arch_post_acpi_subsys_init' [-Werror=missing-prototypes]
init/calibrate.c:261:37: error: no previous prototype for 'calibrate_delay_is_known' [-Werror=missing-prototypes]
kernel/fork.c:991:20: error: no previous prototype for 'arch_task_cache_init' [-Werror=missing-prototypes]

Add prototypes for all of these in include/linux/init.h or another
appropriate header, and remove the duplicate declarations from
architecture specific code.

[[email protected]: declare time_init_early()]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Eric Paris <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Michal Simek <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Paul Moore <[email protected]>
Cc: Pavel Machek <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Russell King <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Waiman Long <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

linux/init.h: include <linux/build_bug.h> and <linux/stringify.h>

With CONFIG_HAVE_ARCH_PREL32_RELOCATIONS=y, the following code fails to
build:

---------------->8----------------
#include <lin

linux/init.h: include <linux/build_bug.h> and <linux/stringify.h>

With CONFIG_HAVE_ARCH_PREL32_RELOCATIONS=y, the following code fails to
build:

---------------->8----------------
#include <linux/init.h>

int foo(void) { return 0; }
core_initcall(foo);
---------------->8----------------

Include <linux/build_bug.h> for static_assert() and <linux/stringify.h>
for __stringify().

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Masahiro Yamada <[email protected]>
Cc: Jiangshan Yi <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Randy Dunlap <[email protected]> # build-tested
Cc: Sami Tolvanen <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

proc: give /proc/cmdline size

Most /proc files don't have length (in fstat sense). This leads to
inefficiencies when reading such files with APIs commonly found in modern
programming languages. Th

proc: give /proc/cmdline size

Most /proc files don't have length (in fstat sense). This leads to
inefficiencies when reading such files with APIs commonly found in modern
programming languages. They open file, then fstat descriptor, get st_size
== 0 and either assume file is empty or start reading without knowing
target size.

cat(1) does OK because it uses large enough buffer by default. But naive
programs copy-pasted from SO aren't:

let mut f = std::fs::File::open("/proc/cmdline").unwrap();
let mut buf: Vec<u8> = Vec::new();
f.read_to_end(&mut buf).unwrap();

will result in

openat(AT_FDCWD, "/proc/cmdline", O_RDONLY|O_CLOEXEC) = 3
statx(0, NULL, AT_STATX_SYNC_AS_STAT, STATX_ALL, NULL) = -1 EFAULT (Bad address)
statx(3, "", AT_STATX_SYNC_AS_STAT|AT_EMPTY_PATH, STATX_ALL, {stx_mask=STATX_BASIC_STATS|STATX_MNT_ID, stx_attributes=0, stx_mode=S_IFREG|0444, stx_size=0, ...}) = 0
lseek(3, 0, SEEK_CUR) = 0
read(3, "BOOT_IMAGE=(hd3,gpt2)/vmlinuz-5.", 32) = 32
read(3, "19.6-100.fc35.x86_64 root=/dev/m", 32) = 32
read(3, "apper/fedora_localhost--live-roo"..., 64) = 64
read(3, "ocalhost--live-swap rd.lvm.lv=fe"..., 128) = 116
read(3, "", 12)

open/stat is OK, lseek looks silly but there are 3 unnecessary reads
because Rust starts with 32 bytes per Vec<u8> and grows from there.

In case of /proc/cmdline, the length is known precisely.

Make variables readonly while I'm at it.

P.S.: I tried to scp /proc/cpuinfo today and got empty file
but this is separate story.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

init.h: fix spelling typo in comment

Fix spelling typo in comment.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jiangshan Yi <[email protected]>
R

init.h: fix spelling typo in comment

Fix spelling typo in comment.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jiangshan Yi <[email protected]>
Reported-by: k2ci <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

treewide: Drop __cficanonical

CONFIG_CFI_CLANG doesn't use a jump table anymore and therefore,
won't change function references to point elsewhere. Remove the
__cficanonical attribute and all uses o

treewide: Drop __cficanonical

CONFIG_CFI_CLANG doesn't use a jump table anymore and therefore,
won't change function references to point elsewhere. Remove the
__cficanonical attribute and all uses of it.

Note that the Clang definition of the attribute was removed earlier,
just clean up the no-op definition and users.

Signed-off-by: Sami Tolvanen <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Tested-by: Kees Cook <[email protected]>
Tested-by: Nathan Chancellor <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Tested-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

init: Drop __nocfi from __init

It's no longer necessary to disable CFI checking for all __init
functions. Drop the __nocfi attribute from __init.

Signed-off-by: Sami Tolvanen <[email protected]

init: Drop __nocfi from __init

It's no longer necessary to disable CFI checking for all __init
functions. Drop the __nocfi attribute from __init.

Signed-off-by: Sami Tolvanen <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Tested-by: Kees Cook <[email protected]>
Tested-by: Nathan Chancellor <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Tested-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

init.h: improve __setup and early_param documentation

Igor noted in [1] that there are quite a few __setup() handling
functions that return incorrect values. Doing this can be harmless, but
it can

init.h: improve __setup and early_param documentation

Igor noted in [1] that there are quite a few __setup() handling
functions that return incorrect values. Doing this can be harmless, but
it can also cause strings to be added to init's argument or environment
list, polluting them.

Since __setup() handling and return values are not documented, first add
documentation for that. Also add more documentation for early_param()
handling and return values.

For __setup() functions, returning 0 (not handled) has questionable
value if it is just a malformed option value, as in

rodata=junk

since returning 0 would just cause "rodata=junk" to be added to init's
environment unnecessarily:

Run /sbin/init as init process
with arguments:
/sbin/init
with environment:
HOME=/
TERM=linux
splash=native
rodata=junk

Also, there are no recommendations on whether to print a warning when an
unknown parameter value is seen. I am not addressing that here.

[1] lore.kernel.org/r/[email protected]

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Randy Dunlap <[email protected]>
Reported-by: Igor Zhbanov <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

init: verify that function is initcall_t at compile-time

In the spirit of making it hard to misuse an interface, add a
compile-time assertion in the CONFIG_HAVE_ARCH_PREL32_RELOCATIONS case
to verif

init: verify that function is initcall_t at compile-time

In the spirit of making it hard to misuse an interface, add a
compile-time assertion in the CONFIG_HAVE_ARCH_PREL32_RELOCATIONS case
to verify the initcall function matches initcall_t, because the inline
asm bypasses any type-checking the compiler would otherwise do. This
will help developers catch incorrect API use in all configurations.

A recent example of this is:
https://lkml.kernel.org/r/[email protected]

Signed-off-by: Marco Elver <[email protected]>
Reviewed-by: Miguel Ojeda <[email protected]>
Reviewed-by: Nathan Chancellor <[email protected]>
Tested-by: Nathan Chancellor <[email protected]>
Reviewed-by: Sami Tolvanen <[email protected]>
Tested-by: Paul E. McKenney <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

cfi: add __cficanonical

With CONFIG_CFI_CLANG, the compiler replaces a function address taken
in C code with the address of a local jump table entry, which passes
runtime indirect call checks. Howev

cfi: add __cficanonical

With CONFIG_CFI_CLANG, the compiler replaces a function address taken
in C code with the address of a local jump table entry, which passes
runtime indirect call checks. However, the compiler won't replace
addresses taken in assembly code, which will result in a CFI failure
if we later jump to such an address in instrumented C code. The code
generated for the non-canonical jump table looks this:

<noncanonical.cfi_jt>: /* In C, &noncanonical points here */
jmp noncanonical
...
<noncanonical>: /* function body */
...

This change adds the __cficanonical attribute, which tells the
compiler to use a canonical jump table for the function instead. This
means the compiler will rename the actual function to <function>.cfi
and points the original symbol to the jump table entry instead:

<canonical>: /* jump table entry */
jmp canonical.cfi
...
<canonical.cfi>: /* function body */
...

As a result, the address taken in assembly, or other non-instrumented
code always points to the jump table and therefore, can be used for
indirect calls in instrumented code without tripping CFI checks.

Signed-off-by: Sami Tolvanen <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Acked-by: Bjorn Helgaas <[email protected]> # pci.h
Tested-by: Nathan Chancellor <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

add support for Clang CFI

This change adds support for Clang’s forward-edge Control Flow
Integrity (CFI) checking. With CONFIG_CFI_CLANG, the compiler
injects a runtime check before each indirect fu

add support for Clang CFI

This change adds support for Clang’s forward-edge Control Flow
Integrity (CFI) checking. With CONFIG_CFI_CLANG, the compiler
injects a runtime check before each indirect function call to ensure
the target is a valid function with the correct static type. This
restricts possible call targets and makes it more difficult for
an attacker to exploit bugs that allow the modification of stored
function pointers. For more details, see:

https://clang.llvm.org/docs/ControlFlowIntegrity.html

Clang requires CONFIG_LTO_CLANG to be enabled with CFI to gain
visibility to possible call targets. Kernel modules are supported
with Clang’s cross-DSO CFI mode, which allows checking between
independently compiled components.

With CFI enabled, the compiler injects a __cfi_check() function into
the kernel and each module for validating local call targets. For
cross-module calls that cannot be validated locally, the compiler
calls the global __cfi_slowpath_diag() function, which determines
the target module and calls the correct __cfi_check() function. This
patch includes a slowpath implementation that uses __module_address()
to resolve call targets, and with CONFIG_CFI_CLANG_SHADOW enabled, a
shadow map that speeds up module look-ups by ~3x.

Clang implements indirect call checking using jump tables and
offers two methods of generating them. With canonical jump tables,
the compiler renames each address-taken function to <function>.cfi
and points the original symbol to a jump table entry, which passes
__cfi_check() validation. This isn’t compatible with stand-alone
assembly code, which the compiler doesn’t instrument, and would
result in indirect calls to assembly code to fail. Therefore, we
default to using non-canonical jump tables instead, where the compiler
generates a local jump table entry <function>.cfi_jt for each
address-taken function, and replaces all references to the function
with the address of the jump table entry.

Note that because non-canonical jump table addresses are local
to each component, they break cross-module function address
equality. Specifically, the address of a global function will be
different in each module, as it's replaced with the address of a local
jump table entry. If this address is passed to a different module,
it won’t match the address of the same function taken there. This
may break code that relies on comparing addresses passed from other
components.

CFI checking can be disabled in a function with the __nocfi attribute.
Additionally, CFI can be disabled for an entire compilation unit by
filtering out CC_FLAGS_CFI.

By default, CFI failures result in a kernel panic to stop a potential
exploit. CONFIG_CFI_PERMISSIVE enables a permissive mode, where the
kernel prints out a rate-limited warning instead, and allows execution
to continue. This option is helpful for locating type mismatches, but
should only be enabled during development.

Signed-off-by: Sami Tolvanen <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Tested-by: Nathan Chancellor <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

init: clean up early_param_on_off() macro

Use early_param() to define early_param_on_off().

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Masahiro Yam

init: clean up early_param_on_off() macro

Use early_param() to define early_param_on_off().

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Masahiro Yamada <[email protected]>
Reviewed-by: Johan Hovold <[email protected]>
Reviewed-by: Miguel Ojeda <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Joe Perches <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

init: lto: fix PREL32 relocations

With LTO, the compiler can rename static functions to avoid global
naming collisions. As initcall functions are typically static,
renaming can break references to t

init: lto: fix PREL32 relocations

With LTO, the compiler can rename static functions to avoid global
naming collisions. As initcall functions are typically static,
renaming can break references to them in inline assembly. This
change adds a global stub with a stable name for each initcall to
fix the issue when PREL32 relocations are used.

Signed-off-by: Sami Tolvanen <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

init: lto: ensure initcall ordering

With LTO, the compiler doesn't necessarily obey the link order for
initcalls, and initcall variables need globally unique names to avoid
collisions at link time.

init: lto: ensure initcall ordering

With LTO, the compiler doesn't necessarily obey the link order for
initcalls, and initcall variables need globally unique names to avoid
collisions at link time.

This change exports __KBUILD_MODNAME and adds the initcall_id() macro,
which uses it together with __COUNTER__ and __LINE__ to help ensure
these variables have unique names, and moves each variable to its own
section when LTO is enabled, so the correct order can be specified using
a linker script.

The generate_initcall_ordering.pl script uses nm to find initcalls from
the object files passed to the linker, and generates a linker script
that specifies the same order for initcalls that we would have without
LTO. With LTO enabled, the script is called in link-vmlinux.sh through
jobserver-exec to limit the number of jobs spawned.

Signed-off-by: Sami Tolvanen <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

init: use type alignment for kernel parameters

Specify type alignment for kernel parameters instead of sizeof(long).

The alignment attribute is used to prevent gcc from increasing the
alignment of

init: use type alignment for kernel parameters

Specify type alignment for kernel parameters instead of sizeof(long).

The alignment attribute is used to prevent gcc from increasing the
alignment of objects with static extent as an optimisation, something
which would mess up the __setup array stride.

Using __alignof__(struct obs_kernel_param) rather than sizeof(long) is
preferred since it better indicates why it is there and doesn't break
should the type size or alignment change.

Note that on m68k the alignment of struct obs_kernel_param is actually
two and that adding a 1- or 2-byte field to the 12-byte struct would
cause a breakage with the current 4-byte alignment.

Link: https://lore.kernel.org/lkml/[email protected]
Signed-off-by: Johan Hovold <[email protected]>
Signed-off-by: Jessica Yu <[email protected]>

show more ...

treewide: Convert macro and uses of __section(foo) to __section("foo")

Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.

Remove the q

treewide: Convert macro and uses of __section(foo) to __section("foo")

Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.

Remove the quote operator # from compiler_attributes.h __section macro.

Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.

Conversion done using the script at:

https://lore.kernel.org/lkml/[email protected]/2-convert_section.pl

Signed-off-by: Joe Perches <[email protected]>
Reviewed-by: Nick Desaulniers <[email protected]>
Reviewed-by: Miguel Ojeda <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

mnt_init(): call shmem_init() unconditionally

No point having two call sites (earlier in init_rootfs() from
mnt_init() in case we are going to use shmem-style rootfs,
later from do_basic_setup() unc

mnt_init(): call shmem_init() unconditionally

No point having two call sites (earlier in init_rootfs() from
mnt_init() in case we are going to use shmem-style rootfs,
later from do_basic_setup() unconditionally), along with the
logics in shmem_init() itself to make the second call a no-op...

Signed-off-by: Al Viro <[email protected]>

show more ...

don't bother with registering rootfs

init_mount_tree() can get to rootfs_fs_type directly and that simplifies
a lot of things. We don't need to register it, we don't need to look
it up *and* we don

don't bother with registering rootfs

init_mount_tree() can get to rootfs_fs_type directly and that simplifies
a lot of things. We don't need to register it, we don't need to look
it up *and* we don't need to bother with preventing subsequent userland
mounts. That's the way we should've done that from the very beginning.

There is a user-visible change, namely the disappearance of "rootfs"
from /proc/filesystems. Note that it's been unmountable all along
and it didn't show up in /proc/mounts; however, it *is* a user-visible
change and theoretically some script might've been using its presence
in /proc/filesystems to tell 2.4.11+ from earlier kernels.

*IF* any complaints about behaviour change do show up, we could fake
it in /proc/filesystems. I very much doubt we'll have to, though.

Signed-off-by: Al Viro <[email protected]>

show more ...

block: remove dead elevator code

This removes a bunch of core and elevator related code. On the core
front, we remove anything related to queue running, draining,
initialization, plugging, and conge

block: remove dead elevator code

This removes a bunch of core and elevator related code. On the core
front, we remove anything related to queue running, draining,
initialization, plugging, and congestions. We also kill anything
related to request allocation, merging, retrieval, and completion.

Remove any checking for single queue IO schedulers, as they no
longer exist. This means we can also delete a bunch of code related
to request issue, adding, completion, etc - and all the SQ related
ops and helpers.

Also kill the load_default_modules(), as all that did was provide
for a way to load the default single queue elevator.

Tested-by: Ming Lei <[email protected]>
Reviewed-by: Omar Sandoval <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

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LSM: Convert from initcall to struct lsm_info

In preparation for doing more interesting LSM init probing, this converts
the existing initcall system into an explicit call into a function pointer
fro

LSM: Convert from initcall to struct lsm_info

In preparation for doing more interesting LSM init probing, this converts
the existing initcall system into an explicit call into a function pointer
from a section-collected struct lsm_info array.

Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Casey Schaufler <[email protected]>
Reviewed-by: James Morris <[email protected]>
Reviewed-by: John Johansen <[email protected]>
Signed-off-by: James Morris <[email protected]>

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