linux-stable.git/net/core/sysctl_net_core.c, branch linux-6.8.y

net: make SK_MEMORY_PCPU_RESERV tunable

2024-05-02T14:35:17+00:00

[ Upstream commit 12a686c2e761f1f1f6e6e2117a9ab9c6de2ac8a7 ]

This patch adds /proc/sys/net/core/mem_pcpu_rsv sysctl file,
to make SK_MEMORY_PCPU_RESERV tunable.

Commit 3cd3399dd7a8 ("net: implement per-cpu reserves for
memory_allocated") introduced per-cpu forward alloc cache:

"Implement a per-cpu cache of +1/-1 MB, to reduce number
of changes to sk->sk_prot->memory_allocated, which
would otherwise be cause of false sharing."

sk_prot->memory_allocated points to global atomic variable:
atomic_long_t tcp_memory_allocated ____cacheline_aligned_in_smp;

If increasing the per-cpu cache size from 1MB to e.g. 16MB,
changes to sk->sk_prot->memory_allocated can be further reduced.
Performance may be improved on system with many cores.

Signed-off-by: Adam Li 
Reviewed-by: Christoph Lameter (Ampere) 
Signed-off-by: David S. Miller 
Stable-dep-of: 3584718cf2ec ("net: fix sk_memory_allocated_{add|sub} vs softirqs")
Signed-off-by: Sasha Levin

net: Namespace-ify sysctl_optmem_max

2023-12-15T11:01:27+00:00

optmem_max being used in tx zerocopy,
we want to be able to control it on a netns basis.

Following patch changes two tests.

Tested:

oqq130:~# cat /proc/sys/net/core/optmem_max
131072
oqq130:~# echo 1000000 >/proc/sys/net/core/optmem_max
oqq130:~# cat /proc/sys/net/core/optmem_max
1000000
oqq130:~# unshare -n
oqq130:~# cat /proc/sys/net/core/optmem_max
131072
oqq130:~# exit
logout
oqq130:~# cat /proc/sys/net/core/optmem_max
1000000

Signed-off-by: Eric Dumazet 
Reviewed-by: Willem de Bruijn 
Acked-by: Neal Cardwell 
Signed-off-by: David S. Miller

networking: Update to register_net_sysctl_sz

2023-08-15T22:26:18+00:00

Move from register_net_sysctl to register_net_sysctl_sz for all the
networking related files. Do this while making sure to mirror the NULL
assignments with a table_size of zero for the unprivileged users.

We need to move to the new function in preparation for when we change
SIZE_MAX to ARRAY_SIZE() in the register_net_sysctl macro. Failing to do
so would erroneously allow ARRAY_SIZE() to be called on a pointer. We
hold off the SIZE_MAX to ARRAY_SIZE change until we have migrated all
the relevant net sysctl registering functions to register_net_sysctl_sz
in subsequent commits.

An additional size function was added to the following files in order to
calculate the size of an array that is defined in another file:
    include/net/ipv6.h
    net/ipv6/icmp.c
    net/ipv6/route.c
    net/ipv6/sysctl_net_ipv6.c

Signed-off-by: Joel Granados 
Signed-off-by: Luis Chamberlain

net/sysctl: Rename kvfree_rcu() to kvfree_rcu_mightsleep()

2023-04-05T13:48:04+00:00

The kfree_rcu() and kvfree_rcu() macros' single-argument forms are
deprecated.  Therefore switch to the new kfree_rcu_mightsleep() and
kvfree_rcu_mightsleep() variants. The goal is to avoid accidental use
of the single-argument forms, which can introduce functionality bugs in
atomic contexts and latency bugs in non-atomic contexts.

Acked-by: Jakub Kicinski 
Cc: Eric Dumazet 
Cc: David S. Miller 
Signed-off-by: Uladzislau Rezki (Sony) 
Signed-off-by: Paul E. McKenney 
Signed-off-by: Joel Fernandes (Google)

net: make default_rps_mask a per netns attribute

2023-02-20T11:22:54+00:00

That really was meant to be a per netns attribute from the beginning.

The idea is that once proper isolation is in place in the main
namespace, additional demux in the child namespaces will be redundant.
Let's make child netns default rps mask empty by default.

To avoid bloating the netns with a possibly large cpumask, allocate
it on-demand during the first write operation.

Signed-off-by: Paolo Abeni 
Signed-off-by: David S. Miller

net: introduce default_rps_mask netns attribute

2023-02-10T01:45:55+00:00

If RPS is enabled, this allows configuring a default rps
mask, which is effective since receive queue creation time.

A default RPS mask allows the system admin to ensure proper
isolation, avoiding races at network namespace or device
creation time.

The default RPS mask is initially empty, and can be
modified via a newly added sysctl entry.

Signed-off-by: Paolo Abeni 
Reviewed-by: Simon Horman 
Reviewed-by: Eric Dumazet 
Signed-off-by: Jakub Kicinski

net-sysctl: factor out cpumask parsing helper

2023-02-10T01:45:55+00:00

Will be used by the following patch to avoid code
duplication. No functional changes intended.

The only difference is that now flow_limit_cpu_sysctl() will
always compute the flow limit mask on each read operation,
even when read() will not return any byte to user-space.

Note that the new helper is placed under a new #ifdef at
the file start to better fit the usage in the later patch

Signed-off-by: Paolo Abeni 
Reviewed-by: Simon Horman 
Reviewed-by: Eric Dumazet 
Signed-off-by: Jakub Kicinski

sysctl: expose all net/core sysctls inside netns

2023-01-06T12:41:52+00:00

All were not visible to the non-priv users inside netns. However,
with 4ecb90090c84 ("sysctl: allow override of /proc/sys/net with
CAP_NET_ADMIN"), these vars are protected from getting modified.
A proc with capable(CAP_NET_ADMIN) can change the values so
not having them visible inside netns is just causing nuisance to
process that check certain values (e.g. net.core.somaxconn) and
see different behavior in root-netns vs. other-netns

Cc: "David S. Miller" 
Cc: Eric Dumazet 
Cc: Jakub Kicinski 
Cc: Paolo Abeni 
Cc: Soheil Hassas Yeganeh 
Signed-off-by: Mahesh Bandewar 
Acked-by: Soheil Hassas Yeganeh 
Signed-off-by: David S. Miller

net: sysctl: remove unused variable long_max

2022-09-07T14:31:19+00:00

The variable long_max is replaced by bpf_jit_limit_max and no longer be
used. So remove it.

No functional change.

Signed-off-by: Liu Shixin 
Signed-off-by: David S. Miller

net: Fix data-races around weight_p and dev_weight_[rt]x_bias.

2022-08-24T12:46:57+00:00

While reading weight_p, it can be changed concurrently.  Thus, we need
to add READ_ONCE() to its reader.

Also, dev_[rt]x_weight can be read/written at the same time.  So, we
need to use READ_ONCE() and WRITE_ONCE() for its access.  Moreover, to
use the same weight_p while changing dev_[rt]x_weight, we add a mutex
in proc_do_dev_weight().

Fixes: 3d48b53fb2ae ("net: dev_weight: TX/RX orthogonality")
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima 
Signed-off-by: David S. Miller