Replace fput() with sockfd_put() in bpf_fd_reuseport_array_update_elem().

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://lore.kernel.org/r/20240830020756.607877-1-ruanjinjie@huawei.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

This allows to do more centralized decisions later on, and generally
makes it very explicit which maps are privileged and which are not
(e.g., LRU_HASH and LRU_PERCPU_HASH, which are privileged HASH variants,
as opposed to unprivileged HASH and HASH_PERCPU; now this is explicit
and easy to verify).

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20230613223533.3689589-4-andrii@kernel.org

This patch changes the return types of bpf_map_ops functions to long, where
previously int was returned. Using long allows for bpf programs to maintain
the sign bit in the absence of sign extension during situations where
inlined bpf helper funcs make calls to the bpf_map_ops funcs and a negative
error is returned.

The definitions of the helper funcs are generated from comments in the bpf
uapi header at `include/uapi/linux/bpf.h`. The return type of these
helpers was previously changed from int to long in commit bdb7b79b4ce8. For
any case where one of the map helpers call the bpf_map_ops funcs that are
still returning 32-bit int, a compiler might not include sign extension
instructions to properly convert the 32-bit negative value a 64-bit
negative value.

For example:
bpf assembly excerpt of an inlined helper calling a kernel function and
checking for a specific error:

; err = bpf_map_update_elem(&mymap, &key, &val, BPF_NOEXIST);
  ...
  46:	call   0xffffffffe103291c	; htab_map_update_elem
; if (err && err != -EEXIST) {
  4b:	cmp    $0xffffffffffffffef,%rax ; cmp -EEXIST,%rax

kernel function assembly excerpt of return value from
`htab_map_update_elem` returning 32-bit int:

movl $0xffffffef, %r9d
...
movl %r9d, %eax

...results in the comparison:
cmp $0xffffffffffffffef, $0x00000000ffffffef

Fixes: bdb7b79b4ce8 ("bpf: Switch most helper return values from 32-bit int to 64-bit long")
Tested-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Link: https://lore.kernel.org/r/20230322194754.185781-3-inwardvessel@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

A new helper is introduced to calculate reuseport_array memory usage.

The result as follows,
- before
14: reuseport_sockarray  name count_map  flags 0x0
        key 4B  value 8B  max_entries 65536  memlock 1048576B

- after
14: reuseport_sockarray  name count_map  flags 0x0
        key 4B  value 8B  max_entries 65536  memlock 524544B

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-7-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

bpf_sk_reuseport_detach() calls __rcu_dereference_sk_user_data_with_flags()
to obtain the value of sk->sk_user_data, but that function is only usable
if the RCU read lock is held, and neither that function nor any of its
callers hold it.

Fix this by adding a new helper, __locked_read_sk_user_data_with_flags()
that checks to see if sk->sk_callback_lock() is held and use that here
instead.

Alternatively, making __rcu_dereference_sk_user_data_with_flags() use
rcu_dereference_checked() might suffice.

Without this, the following warning can be occasionally observed:

=============================
WARNING: suspicious RCU usage
6.0.0-rc1-build2+ #563 Not tainted
-----------------------------
include/net/sock.h:592 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
5 locks held by locktest/29873:
 #0: ffff88812734b550 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: __sock_release+0x77/0x121
 #1: ffff88812f5621b0 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_close+0x1c/0x70
 #2: ffff88810312f5c8 (&h->lhash2[i].lock){+.+.}-{2:2}, at: inet_unhash+0x76/0x1c0
 #3: ffffffff83768bb8 (reuseport_lock){+...}-{2:2}, at: reuseport_detach_sock+0x18/0xdd
 #4: ffff88812f562438 (clock-AF_INET){++..}-{2:2}, at: bpf_sk_reuseport_detach+0x24/0xa4

stack backtrace:
CPU: 1 PID: 29873 Comm: locktest Not tainted 6.0.0-rc1-build2+ #563
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x4c/0x5f
 bpf_sk_reuseport_detach+0x6d/0xa4
 reuseport_detach_sock+0x75/0xdd
 inet_unhash+0xa5/0x1c0
 tcp_set_state+0x169/0x20f
 ? lockdep_sock_is_held+0x3a/0x3a
 ? __lock_release.isra.0+0x13e/0x220
 ? reacquire_held_locks+0x1bb/0x1bb
 ? hlock_class+0x31/0x96
 ? mark_lock+0x9e/0x1af
 __tcp_close+0x50/0x4b6
 tcp_close+0x28/0x70
 inet_release+0x8e/0xa7
 __sock_release+0x95/0x121
 sock_close+0x14/0x17
 __fput+0x20f/0x36a
 task_work_run+0xa3/0xcc
 exit_to_user_mode_prepare+0x9c/0x14d
 syscall_exit_to_user_mode+0x18/0x44
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: cf8c1e967224 ("net: refactor bpf_sk_reuseport_detach()")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Hawkins Jiawei <yin31149@gmail.com>
Link: https://lore.kernel.org/r/166064248071.3502205.10036394558814861778.stgit@warthog.procyon.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Refactor sk_user_data dereference using more generic function
__rcu_dereference_sk_user_data_with_flags(), which improve its
maintainability

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

For now, the field 'map_btf_id' in 'struct bpf_map_ops' for all map
types are computed during vmlinux-btf init:

  btf_parse_vmlinux() -> btf_vmlinux_map_ids_init()

It will lookup the btf_type according to the 'map_btf_name' field in
'struct bpf_map_ops'. This process can be done during build time,
thanks to Jiri's resolve_btfids.

selftest of map_ptr has passed:

  $96 map_ptr:OK
  Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Add leading space to spdx tag
Use // for spdx c file comment

Replacements
resereved to reserved
inbetween to in between
everytime to every time
intutivie to intuitive
currenct to current
encontered to encountered
referenceing to referencing
upto to up to
exectuted to executed

Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20220220184055.3608317-1-trix@redhat.com

In an effort to avoid open-coded arithmetic in the kernel, use the
struct_size() helper instead of open-coded calculation.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://github.com/KSPP/linux/issues/160
Link: https://lore.kernel.org/bpf/20211220113048.2859-1-xiujianfeng@huawei.com

Fix some spelling mistakes in comments:
aother ==> another
Netiher ==> Neither
desribe ==> describe
intializing ==> initializing
funciton ==> function
wont ==> won't and move the word 'the' at the end to the next line
accross ==> across
pathes ==> paths
triggerred ==> triggered
excute ==> execute
ether ==> either
conervative ==> conservative
convetion ==> convention
markes ==> marks
interpeter ==> interpreter

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210525025659.8898-2-thunder.leizhen@huawei.com