linux.git/kernel/sysctl.c, branch v5.10.194

sysctl: move some boundary constants from sysctl.c to sysctl_vals

2023-06-28T08:28:09+00:00

[ Upstream commit 78e36f3b0dae586f623c4a37ec5eb5496f5abbe1 ]

sysctl has helpers which let us specify boundary values for a min or max
int value.  Since these are used for a boundary check only they don't
change, so move these variables to sysctl_vals to avoid adding duplicate
variables.  This will help with our cleanup of kernel/sysctl.c.

[akpm@linux-foundation.org: update it for "mm/pagealloc: sysctl: change watermark_scale_factor max limit to 30%"]
[mcgrof@kernel.org: major rebase]

Link: https://lkml.kernel.org/r/20211123202347.818157-3-mcgrof@kernel.org
Signed-off-by: Xiaoming Ni 
Signed-off-by: Luis Chamberlain 
Reviewed-by: Kees Cook 
Cc: Al Viro 
Cc: Amir Goldstein 
Cc: Andy Shevchenko 
Cc: Benjamin LaHaise 
Cc: "Eric W. Biederman" 
Cc: Greg Kroah-Hartman 
Cc: Iurii Zaikin 
Cc: Jan Kara 
Cc: Paul Turner 
Cc: Peter Zijlstra 
Cc: Petr Mladek 
Cc: Qing Wang 
Cc: Sebastian Reichel 
Cc: Sergey Senozhatsky 
Cc: Stephen Kitt 
Cc: Tetsuo Handa 
Cc: Antti Palosaari 
Cc: Arnd Bergmann 
Cc: Benjamin Herrenschmidt 
Cc: Clemens Ladisch 
Cc: David Airlie 
Cc: Jani Nikula 
Cc: Joel Becker 
Cc: Joonas Lahtinen 
Cc: Joseph Qi 
Cc: Julia Lawall 
Cc: Lukas Middendorf 
Cc: Mark Fasheh 
Cc: Phillip Potter 
Cc: Rodrigo Vivi 
Cc: Douglas Gilbert 
Cc: James E.J. Bottomley 
Cc: Jani Nikula 
Cc: John Ogness 
Cc: Martin K. Petersen 
Cc: "Rafael J. Wysocki" 
Cc: Steven Rostedt (VMware) 
Cc: Suren Baghdasaryan 
Cc: "Theodore Ts'o" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Stable-dep-of: 935d44acf621 ("memfd: check for non-NULL file_seals in memfd_create() syscall")
Signed-off-by: Sasha Levin

mm/pagealloc: sysctl: change watermark_scale_factor max limit to 30%

2023-06-28T08:28:09+00:00

[ Upstream commit 39c65a94cd9661532be150e88f8b02f4a6844a35 ]

For embedded systems with low total memory, having to run applications
with relatively large memory requirements, 10% max limitation for
watermark_scale_factor poses an issue of triggering direct reclaim every
time such application is started.  This results in slow application
startup times and bad end-user experience.

By increasing watermark_scale_factor max limit we allow vendors more
flexibility to choose the right level of kswapd aggressiveness for their
device and workload requirements.

Link: https://lkml.kernel.org/r/20211124193604.2758863-1-surenb@google.com
Signed-off-by: Suren Baghdasaryan 
Acked-by: Johannes Weiner 
Cc: Michal Hocko 
Cc: Lukas Middendorf 
Cc: Antti Palosaari 
Cc: Luis Chamberlain 
Cc: Kees Cook 
Cc: Iurii Zaikin 
Cc: Dave Hansen 
Cc: Vlastimil Babka 
Cc: Mel Gorman 
Cc: Jonathan Corbet 
Cc: Zhang Yi 
Cc: Fengfei Xi 
Cc: Mike Rapoport 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Stable-dep-of: 935d44acf621 ("memfd: check for non-NULL file_seals in memfd_create() syscall")
Signed-off-by: Sasha Levin

sysctl: Fix data-races in proc_dou8vec_minmax().

2023-04-20T10:10:29+00:00

commit 7dee5d7747a69aa2be41f04c6a7ecfe3ac8cdf18 upstream.

A sysctl variable is accessed concurrently, and there is always a chance
of data-race.  So, all readers and writers need some basic protection to
avoid load/store-tearing.

This patch changes proc_dou8vec_minmax() to use READ_ONCE() and
WRITE_ONCE() internally to fix data-races on the sysctl side.  For now,
proc_dou8vec_minmax() itself is tolerant to a data-race, but we still
need to add annotations on the other subsystem's side.

Fixes: cb9444130662 ("sysctl: add proc_dou8vec_minmax()")
Signed-off-by: Kuniyuki Iwashima 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

sysctl: add proc_dou8vec_minmax()

2023-04-20T10:10:26+00:00

[ Upstream commit cb9444130662c6c13022579c861098f212db2562 ]

Networking has many sysctls that could fit in one u8.

This patch adds proc_dou8vec_minmax() for this purpose.

Note that the .extra1 and .extra2 fields are pointing
to integers, because it makes conversions easier.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Stable-dep-of: dc5110c2d959 ("tcp: restrict net.ipv4.tcp_app_win")
Signed-off-by: Sasha Levin

kernel/panic: move panic sysctls to its own file

2023-02-01T07:23:18+00:00

commit 9df918698408fd914493aba0b7858fef50eba63a upstream.

kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.

To help with this maintenance let's start by moving sysctls to places
where they actually belong.  The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we
just care about the core logic.

All filesystem syctls now get reviewed by fs folks. This commit
follows the commit of fs, move the oops_all_cpu_backtrace sysctl to
its own file, kernel/panic.c.

Signed-off-by: tangmeng 
Signed-off-by: Luis Chamberlain 
Signed-off-by: Eric Biggers 
Signed-off-by: Sasha Levin

proc: proc_skip_spaces() shouldn't think it is working on C strings

2022-12-08T10:24:00+00:00

commit bce9332220bd677d83b19d21502776ad555a0e73 upstream.

proc_skip_spaces() seems to think it is working on C strings, and ends
up being just a wrapper around skip_spaces() with a really odd calling
convention.

Instead of basing it on skip_spaces(), it should have looked more like
proc_skip_char(), which really is the exact same function (except it
skips a particular character, rather than whitespace).  So use that as
inspiration, odd coding and all.

Now the calling convention actually makes sense and works for the
intended purpose.

Reported-and-tested-by: Kyle Zeng 
Acked-by: Eric Dumazet 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

proc: avoid integer type confusion in get_proc_long

2022-12-08T10:23:59+00:00

commit e6cfaf34be9fcd1a8285a294e18986bfc41a409c upstream.

proc_get_long() is passed a size_t, but then assigns it to an 'int'
variable for the length.  Let's not do that, even if our IO paths are
limited to MAX_RW_COUNT (exactly because of these kinds of type errors).

So do the proper test in the rigth type.

Reported-by: Kyle Zeng 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm: sysctl: fix missing numa_stat when !CONFIG_HUGETLB_PAGE

2022-07-21T19:20:13+00:00

[ Upstream commit 43b5240ca6b33108998810593248186b1e3ae34a ]

"numa_stat" should not be included in the scope of CONFIG_HUGETLB_PAGE, if
CONFIG_HUGETLB_PAGE is not configured even if CONFIG_NUMA is configured,
"numa_stat" is missed form /proc. Move it out of CONFIG_HUGETLB_PAGE to
fix it.

Fixes: 4518085e127d ("mm, sysctl: make NUMA stats configurable")
Signed-off-by: Muchun Song 
Cc: 
Acked-by: Michal Hocko 
Acked-by: Mel Gorman 
Signed-off-by: Luis Chamberlain 
Signed-off-by: Sasha Levin

sysctl: Fix data-races in proc_dointvec_ms_jiffies().

2022-07-21T19:20:09+00:00

[ Upstream commit 7d1025e559782b58824b36cb8ad547a69f2e4b31 ]

A sysctl variable is accessed concurrently, and there is always a chance
of data-race.  So, all readers and writers need some basic protection to
avoid load/store-tearing.

This patch changes proc_dointvec_ms_jiffies() to use READ_ONCE() and
WRITE_ONCE() internally to fix data-races on the sysctl side.  For now,
proc_dointvec_ms_jiffies() itself is tolerant to a data-race, but we still
need to add annotations on the other subsystem's side.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

sysctl: Fix data races in proc_dointvec_jiffies().

2022-07-21T19:20:07+00:00

[ Upstream commit e877820877663fbae8cb9582ea597a7230b94df3 ]

A sysctl variable is accessed concurrently, and there is always a chance
of data-race.  So, all readers and writers need some basic protection to
avoid load/store-tearing.

This patch changes proc_dointvec_jiffies() to use READ_ONCE() and
WRITE_ONCE() internally to fix data-races on the sysctl side.  For now,
proc_dointvec_jiffies() itself is tolerant to a data-race, but we still
need to add annotations on the other subsystem's side.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin