s390: Move s390 sysctls into their own file under arch/s390

Move s390 sysctls (spin_retry and userprocess_debug) into their own
files under arch/s390. Create two new sysctl tables
(2390_{fault,spin}

s390: Move s390 sysctls into their own file under arch/s390

Move s390 sysctls (spin_retry and userprocess_debug) into their own
files under arch/s390. Create two new sysctl tables
(2390_{fault,spin}_sysctl_table) which will be initialized with
arch_initcall placing them after their original place in proc_root_init.

This is part of a greater effort to move ctl tables into their
respective subsystems which will reduce the merge conflicts in
kernel/sysctl.c.

Signed-off-by: joel granados <[email protected]>
Acked-by: Heiko Carstens <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vasily Gorbik <[email protected]>

show more ...

perf/core: Move perf_event sysctls into kernel/events

Move ctl tables to two files:

- perf_event_{paranoid,mlock_kb,max_sample_rate} and
perf_cpu_time_max_percent into kernel/events/core.c

-

perf/core: Move perf_event sysctls into kernel/events

Move ctl tables to two files:

- perf_event_{paranoid,mlock_kb,max_sample_rate} and
perf_cpu_time_max_percent into kernel/events/core.c

- perf_event_max_{stack,context_per_stack} into
kernel/events/callchain.c

Make static variables and functions that are fully contained in core.c
and callchain.cand remove them from include/linux/perf_event.h.
Additionally six_hundred_forty_kb is moved to callchain.c.

Two new sysctl tables are added ({callchain,events_core}_sysctl_table)
with their respective sysctl registration functions.

This is part of a greater effort to move ctl tables into their
respective subsystems which will reduce the merge conflicts in
kerenel/sysctl.c.

Signed-off-by: Joel Granados <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

x86: Move sysctls into arch/x86

Move the following sysctl tables into arch/x86/kernel/setup.c:

panic_on_{unrecoverable_nmi,io_nmi}
bootloader_{type,version}
io_delay_type
unknown_nmi_panic

x86: Move sysctls into arch/x86

Move the following sysctl tables into arch/x86/kernel/setup.c:

panic_on_{unrecoverable_nmi,io_nmi}
bootloader_{type,version}
io_delay_type
unknown_nmi_panic
acpi_realmode_flags

Variables moved from include/linux/ to arch/x86/include/asm/ because there
is no longer need for them outside arch/x86/kernel:

acpi_realmode_flags
panic_on_{unrecoverable_nmi,io_nmi}

Include <asm/nmi.h> in arch/s86/kernel/setup.h in order to bring in
panic_on_{io_nmi,unrecovered_nmi}.

This is part of a greater effort to move ctl tables into their
respective subsystems which will reduce the merge conflicts in
kerenel/sysctl.c.

Signed-off-by: Joel Granados <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

sysctl: remove unneeded include

Removing unneeded mm includes in kernel/sysctl.c.

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Kalesh AP

sysctl: remove unneeded include

Removing unneeded mm includes in kernel/sysctl.c.

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Kalesh AP <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

sysctl: remove the vm_table

After patch1~14 is applied, all sysctls of vm_table
would be moved. So, delete vm_table.

Signed-off-by: Kaixiong Yu <[email protected]>
Signed-off-by: Joel Granados

sysctl: remove the vm_table

After patch1~14 is applied, all sysctls of vm_table
would be moved. So, delete vm_table.

Signed-off-by: Kaixiong Yu <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

sh: vdso: move the sysctl to arch/sh/kernel/vsyscall/vsyscall.c

When CONFIG_SUPERH and CONFIG_VSYSCALL are defined,
vdso_enabled belongs to arch/sh/kernel/vsyscall/vsyscall.c.
So, move it into its o

sh: vdso: move the sysctl to arch/sh/kernel/vsyscall/vsyscall.c

When CONFIG_SUPERH and CONFIG_VSYSCALL are defined,
vdso_enabled belongs to arch/sh/kernel/vsyscall/vsyscall.c.
So, move it into its own file. To avoid failure when registering
the vdso_table, move the call to register_sysctl_init() into
its own fs_initcall().

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

x86: vdso: move the sysctl to arch/x86/entry/vdso/vdso32-setup.c

When CONFIG_X86_32 is defined and CONFIG_UML is not defined,
vdso_enabled belongs to arch/x86/entry/vdso/vdso32-setup.c.
So, move it

x86: vdso: move the sysctl to arch/x86/entry/vdso/vdso32-setup.c

When CONFIG_X86_32 is defined and CONFIG_UML is not defined,
vdso_enabled belongs to arch/x86/entry/vdso/vdso32-setup.c.
So, move it into its own file.

Before this patch, vdso_enabled was allowed to be set to
a value exceeding 1 on x86_32 architecture. After this patch is
applied, vdso_enabled is not permitted to set the value more than 1.
It does not matter, because according to the function load_vdso32(),
only vdso_enabled is set to 1, VDSO would be enabled. Other values
all mean "disabled". The same limitation could be seen in the
function vdso32_setup().

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

fs: dcache: move the sysctl to fs/dcache.c

The sysctl_vfs_cache_pressure belongs to fs/dcache.c, move it to
fs/dcache.c from kernel/sysctl.c. As a part of fs/dcache.c cleaning,
sysctl_vfs_cache_pres

fs: dcache: move the sysctl to fs/dcache.c

The sysctl_vfs_cache_pressure belongs to fs/dcache.c, move it to
fs/dcache.c from kernel/sysctl.c. As a part of fs/dcache.c cleaning,
sysctl_vfs_cache_pressure is changed to a static variable, and change
the inline-type function vfs_pressure_ratio() to out-of-inline type,
export vfs_pressure_ratio() with EXPORT_SYMBOL_GPL to be used by other
files. Move the unneeded include(linux/dcache.h).

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Reviewed-by: Christian Brauner <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

fs: drop_caches: move sysctl to fs/drop_caches.c

The sysctl_drop_caches to fs/drop_caches.c, move it to
fs/drop_caches.c from /kernel/sysctl.c. And remove the
useless extern variable declaration fro

fs: drop_caches: move sysctl to fs/drop_caches.c

The sysctl_drop_caches to fs/drop_caches.c, move it to
fs/drop_caches.c from /kernel/sysctl.c. And remove the
useless extern variable declaration from include/linux/mm.h

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Reviewed-by: Christian Brauner <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

fs: fs-writeback: move sysctl to fs/fs-writeback.c

The dirtytime_expire_interval belongs to fs/fs-writeback.c, move it to
fs/fs-writeback.c from /kernel/sysctl.c. And remove the useless extern
varia

fs: fs-writeback: move sysctl to fs/fs-writeback.c

The dirtytime_expire_interval belongs to fs/fs-writeback.c, move it to
fs/fs-writeback.c from /kernel/sysctl.c. And remove the useless extern
variable declaration and the function declaration from
include/linux/writeback.h

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

mm: nommu: move sysctl to mm/nommu.c

The sysctl_nr_trim_pages belongs to nommu.c, move it to mm/nommu.c
from /kernel/sysctl.c. And remove the useless extern variable declaration
from include/linux/m

mm: nommu: move sysctl to mm/nommu.c

The sysctl_nr_trim_pages belongs to nommu.c, move it to mm/nommu.c
from /kernel/sysctl.c. And remove the useless extern variable declaration
from include/linux/mm.h

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Lorenzo Stoakes <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

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security: min_addr: move sysctl to security/min_addr.c

The dac_mmap_min_addr belongs to min_addr.c, move it to
min_addr.c from /kernel/sysctl.c. In the previous Linux kernel
boot process, sysctl_ini

security: min_addr: move sysctl to security/min_addr.c

The dac_mmap_min_addr belongs to min_addr.c, move it to
min_addr.c from /kernel/sysctl.c. In the previous Linux kernel
boot process, sysctl_init_bases needs to be executed before
init_mmap_min_addr, So, register_sysctl_init should be executed
before update_mmap_min_addr in init_mmap_min_addr. And according
to the compilation condition in security/Makefile:

obj-$(CONFIG_MMU) += min_addr.o

if CONFIG_MMU is not defined, min_addr.c would not be included in the
compilation process. So, drop the CONFIG_MMU check.

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Acked-by: Paul Moore <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

mm: mmap: move sysctl to mm/mmap.c

This moves all mmap related sysctls to mm/mmap.c, as part of the
kernel/sysctl.c cleaning, also move the variable declaration from
kernel/sysctl.c into mm/mmap.c.

mm: mmap: move sysctl to mm/mmap.c

This moves all mmap related sysctls to mm/mmap.c, as part of the
kernel/sysctl.c cleaning, also move the variable declaration from
kernel/sysctl.c into mm/mmap.c.

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Lorenzo Stoakes <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

mm: util: move sysctls to mm/util.c

This moves all util related sysctls to mm/util.c, as part of the
kernel/sysctl.c cleaning, also removes redundant external
variable declarations and function decl

mm: util: move sysctls to mm/util.c

This moves all util related sysctls to mm/util.c, as part of the
kernel/sysctl.c cleaning, also removes redundant external
variable declarations and function declarations.

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

mm: vmscan: move vmscan sysctls to mm/vmscan.c

This moves vm_swappiness and zone_reclaim_mode to mm/vmscan.c,
as part of the kernel/sysctl.c cleaning, also moves some external
variable declarations

mm: vmscan: move vmscan sysctls to mm/vmscan.c

This moves vm_swappiness and zone_reclaim_mode to mm/vmscan.c,
as part of the kernel/sysctl.c cleaning, also moves some external
variable declarations and function declarations from include/linux/swap.h
into mm/internal.h.

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

mm: swap: move sysctl to mm/swap.c

The page-cluster belongs to mm/swap.c, move it to mm/swap.c .
Removes the redundant external variable declaration and unneeded
include(linux/swap.h).

Signed-off-b

mm: swap: move sysctl to mm/swap.c

The page-cluster belongs to mm/swap.c, move it to mm/swap.c .
Removes the redundant external variable declaration and unneeded
include(linux/swap.h).

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

mm: filemap: move sysctl to mm/filemap.c

This moves the filemap related sysctl to mm/filemap.c, and
removes the redundant external variable declaration.

Signed-off-by: Kaixiong Yu <yukaixiong@huawe

mm: filemap: move sysctl to mm/filemap.c

This moves the filemap related sysctl to mm/filemap.c, and
removes the redundant external variable declaration.

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

mm: vmstat: move sysctls to mm/vmstat.c

This moves all vmstat related sysctls to its own file, removes useless
extern variable declarations, and do some related clean-ups. To avoid
compiler warnings

mm: vmstat: move sysctls to mm/vmstat.c

This moves all vmstat related sysctls to its own file, removes useless
extern variable declarations, and do some related clean-ups. To avoid
compiler warnings when CONFIG_PROC_FS is not defined, add the macro
definition CONFIG_PROC_FS ahead CONFIG_NUMA in vmstat.c.

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

treewide: const qualify ctl_tables where applicable

Add the const qualifier to all the ctl_tables in the tree except for
watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls,
loadpin_sysc

treewide: const qualify ctl_tables where applicable

Add the const qualifier to all the ctl_tables in the tree except for
watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls,
loadpin_sysctl_table and the ones calling register_net_sysctl (./net,
drivers/inifiniband dirs). These are special cases as they use a
registration function with a non-const qualified ctl_table argument or
modify the arrays before passing them on to the registration function.

Constifying ctl_table structs will prevent the modification of
proc_handler function pointers as the arrays would reside in .rodata.
This is made possible after commit 78eb4ea25cd5 ("sysctl: treewide:
constify the ctl_table argument of proc_handlers") constified all the
proc_handlers.

Created this by running an spatch followed by a sed command:
Spatch:
virtual patch

@
depends on !(file in "net")
disable optional_qualifier
@

identifier table_name != {
watchdog_hardlockup_sysctl,
iwcm_ctl_table,
ucma_ctl_table,
memory_allocation_profiling_sysctls,
loadpin_sysctl_table
};
@@

+ const
struct ctl_table table_name [] = { ... };

sed:
sed --in-place \
-e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \
kernel/utsname_sysctl.c

Reviewed-by: Song Liu <[email protected]>
Acked-by: Steven Rostedt (Google) <[email protected]> # for kernel/trace/
Reviewed-by: Martin K. Petersen <[email protected]> # SCSI
Reviewed-by: Darrick J. Wong <[email protected]> # xfs
Acked-by: Jani Nikula <[email protected]>
Acked-by: Corey Minyard <[email protected]>
Acked-by: Wei Liu <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
Reviewed-by: Bill O'Donnell <[email protected]>
Acked-by: Baoquan He <[email protected]>
Acked-by: Ashutosh Dixit <[email protected]>
Acked-by: Anna Schumaker <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

pid: allow pid_max to be set per pid namespace

The pid_max sysctl is a global value. For a long time the default value
has been 65535 and during the pidfd dicussions Linus proposed to bump
pid_max b

pid: allow pid_max to be set per pid namespace

The pid_max sysctl is a global value. For a long time the default value
has been 65535 and during the pidfd dicussions Linus proposed to bump
pid_max by default (cf. [1]). Based on this discussion systemd started
bumping pid_max to 2^22. So all new systems now run with a very high
pid_max limit with some distros having also backported that change.
The decision to bump pid_max is obviously correct. It just doesn't make
a lot of sense nowadays to enforce such a low pid number. There's
sufficient tooling to make selecting specific processes without typing
really large pid numbers available.

In any case, there are workloads that have expections about how large
pid numbers they accept. Either for historical reasons or architectural
reasons. One concreate example is the 32-bit version of Android's bionic
libc which requires pid numbers less than 65536. There are workloads
where it is run in a 32-bit container on a 64-bit kernel. If the host
has a pid_max value greater than 65535 the libc will abort thread
creation because of size assumptions of pthread_mutex_t.

That's a fairly specific use-case however, in general specific workloads
that are moved into containers running on a host with a new kernel and a
new systemd can run into issues with large pid_max values. Obviously
making assumptions about the size of the allocated pid is suboptimal but
we have userspace that does it.

Of course, giving containers the ability to restrict the number of
processes in their respective pid namespace indepent of the global limit
through pid_max is something desirable in itself and comes in handy in
general.

Independent of motivating use-cases the existence of pid namespaces
makes this also a good semantical extension and there have been prior
proposals pushing in a similar direction.
The trick here is to minimize the risk of regressions which I think is
doable. The fact that pid namespaces are hierarchical will help us here.

What we mostly care about is that when the host sets a low pid_max
limit, say (crazy number) 100 that no descendant pid namespace can
allocate a higher pid number in its namespace. Since pid allocation is
hierarchial this can be ensured by checking each pid allocation against
the pid namespace's pid_max limit. This means if the allocation in the
descendant pid namespace succeeds, the ancestor pid namespace can reject
it. If the ancestor pid namespace has a higher limit than the descendant
pid namespace the descendant pid namespace will reject the pid
allocation. The ancestor pid namespace will obviously not care about
this.
All in all this means pid_max continues to enforce a system wide limit
on the number of processes but allows pid namespaces sufficient leeway
in handling workloads with assumptions about pid values and allows
containers to restrict the number of processes in a pid namespace
through the pid_max interface.

[1]: https://lore.kernel.org/linux-api/CAHk-=wiZ40LVjnXSi9iHLE_-ZBsWFGCgdmNiYZUXn1-V5YBg2g@mail.gmail.com
- rebased from 5.14-rc1
- a few fixes (missing ns_free_inum on error path, missing initialization, etc)
- permission check changes in pid_table_root_permissions
- unsigned int pid_max -> int pid_max (keep pid_max type as it was)
- add READ_ONCE in alloc_pid() as suggested by Christian
- rebased from 6.7 and take into account:
* sysctl: treewide: drop unused argument ctl_table_root::set_ownership(table)
* sysctl: treewide: constify ctl_table_header::ctl_table_arg
* pidfd: add pidfs
* tracing: Move saved_cmdline code into trace_sched_switch.c

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

show more ...

sysctl: Reorganize kerneldoc parameter names

Reorganize kerneldoc parameter names to match the parameter
order in the function header.

Problems identified using Coccinelle.

Signed-off-by: Julia La

sysctl: Reorganize kerneldoc parameter names

Reorganize kerneldoc parameter names to match the parameter
order in the function header.

Problems identified using Coccinelle.

Signed-off-by: Julia Lawall <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

sysctl: treewide: constify the ctl_table argument of proc_handlers

const qualify the struct ctl_table argument in the proc_handler function
signatures. This is a prerequisite to moving the static ct

sysctl: treewide: constify the ctl_table argument of proc_handlers

const qualify the struct ctl_table argument in the proc_handler function
signatures. This is a prerequisite to moving the static ctl_table
structs into .rodata data which will ensure that proc_handler function
pointers cannot be modified.

This patch has been generated by the following coccinelle script:

```
virtual patch

@r1@
identifier ctl, write, buffer, lenp, ppos;
identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)";
@@

int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int write, void *buffer, size_t *lenp, loff_t *ppos);

@r2@
identifier func, ctl, write, buffer, lenp, ppos;
@@

int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int write, void *buffer, size_t *lenp, loff_t *ppos)
{ ... }

@r3@
identifier func;
@@

int func(
- struct ctl_table *
+ const struct ctl_table *
,int , void *, size_t *, loff_t *);

@r4@
identifier func, ctl;
@@

int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int , void *, size_t *, loff_t *);

@r5@
identifier func, write, buffer, lenp, ppos;
@@

int func(
- struct ctl_table *
+ const struct ctl_table *
,int write, void *buffer, size_t *lenp, loff_t *ppos);

```

* Code formatting was adjusted in xfs_sysctl.c to comply with code
conventions. The xfs_stats_clear_proc_handler,
xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where
adjusted.

* The ctl_table argument in proc_watchdog_common was const qualified.
This is called from a proc_handler itself and is calling back into
another proc_handler, making it necessary to change it as part of the
proc_handler migration.

Co-developed-by: Thomas Weißschuh <[email protected]>
Signed-off-by: Thomas Weißschuh <[email protected]>
Co-developed-by: Joel Granados <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

sysctl: constify ctl_table arguments of utility function

In a future commit the proc_handlers themselves will change to
"const struct ctl_table". As a preparation for that adapt the internal
helper.

sysctl: constify ctl_table arguments of utility function

In a future commit the proc_handlers themselves will change to
"const struct ctl_table". As a preparation for that adapt the internal
helper.

Signed-off-by: Thomas Weißschuh <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

sysctl: move the extra1/2 boundary check of u8 to sysctl_check_table_array

Move boundary checking for proc_dou8ved_minmax into module loading, thereby
reporting errors in advance. And add a kunit te

sysctl: move the extra1/2 boundary check of u8 to sysctl_check_table_array

Move boundary checking for proc_dou8ved_minmax into module loading, thereby
reporting errors in advance. And add a kunit test case ensuring the
boundary check is done correctly.

The boundary check in proc_dou8vec_minmax done to the extra elements in
the ctl_table struct is currently performed at runtime. This allows buggy
kernel modules to be loaded normally without any errors only to fail
when used.

This is a buggy example module:
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sysctl.h>

static struct ctl_table_header *_table_header = NULL;
static unsigned char _data = 0;
struct ctl_table table[] = {
{
.procname = "foo",
.data = &_data,
.maxlen = sizeof(u8),
.mode = 0644,
.proc_handler = proc_dou8vec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE_THOUSAND,
},
};

static int init_demo(void) {
_table_header = register_sysctl("kernel", table);
if (!_table_header)
return -ENOMEM;

return 0;
}

module_init(init_demo);
MODULE_LICENSE("GPL");

And this is the result:
# insmod test.ko
# cat /proc/sys/kernel/foo
cat: /proc/sys/kernel/foo: Invalid argument

Suggested-by: Joel Granados <[email protected]>
Signed-off-by: Wen Yang <[email protected]>
Cc: Luis Chamberlain <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Joel Granados <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: [email protected]
Reviewed-by: Joel Granados <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

kernel misc: Remove the now superfluous sentinel elements from ctl_table array

This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (

kernel misc: Remove the now superfluous sentinel elements from ctl_table array

This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which
will reduce the overall build time size of the kernel and run time
memory bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%[email protected]/)

Remove the sentinel from ctl_table arrays. Reduce by one the values used
to compare the size of the adjusted arrays.

Signed-off-by: Joel Granados <[email protected]>

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