'libcap' is unused since commit b1c2768a ("bpf: selftests: Remove libcap
usage from test_verifier"). Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240602234112.225107-4-linux@treblig.org

'key_t' is unused in a couple of files since the original commit 60dd49ea
("selftests/bpf: Add test for bpf array map iterators"). Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240602234112.225107-3-linux@treblig.org

'scale_test_def' is unused since commit 3762a39c ("selftests/bpf: Split out
bpf_verif_scale selftests into multiple tests"). Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240602234112.225107-2-linux@treblig.org

Zba extension is very useful for generating addresses that index into array
of basic data types. This patch introduces sh2add and sh3add helpers for
RV32 and RV64 respectively, to accelerate addressing for array of unsigned
long data.
Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Björn Töpel <bjorn@kernel.org>
Link: https://lore.kernel.org/bpf/20240524075543.4050464-3-xiao.w.wang@intel.com

Make sure to preserve and/or enforce FD_CLOEXEC flag on duped FDs.
Use dup3() with O_CLOEXEC flag for that.

Without this fix libbpf effectively clears FD_CLOEXEC flag on each of BPF
map/prog FD, which is definitely not the right or expected behavior.
Reported-by: Lennart Poettering <lennart@poettering.net>
Fixes: bc308d01 ("libbpf: call dup2() syscall directly")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20240529223239.504241-1-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Kui-Feng Lee says:

====================
The subsystems managing struct_ops objects may need to detach a
struct_ops object due to errors or other reasons. It would be useful
to notify user space programs so that error recovery or logging can be
carried out.

This patch set enables the detach feature for struct_ops links and
send an event to epoll when a link is detached.  Subsystems could call
link->ops->detach() to detach a link and notify user space programs
through epoll.

The signatures of callback functions in "struct bpf_struct_ops" have
been changed as well to pass an extra link argument to
subsystems. Subsystems could detach the links received from reg() and
update() callbacks if there is. This also provides a way that
subsystems can distinguish registrations for an object that has been
registered multiple times for several links.

However, bpf struct_ops maps without BPF_F_LINK have no any link.
Subsystems will receive NULL link pointer for this case.
---
Changes from v6:

 - Fix the missing header at patch 5.

 - Move RCU_INIT_POINTER() back to its original position.

Changes from v5:

 - Change the commit title of the patch for bpftool.

Changes from v4:

 - Change error code for bpf_struct_ops_map_link_update()

 - Always return 0 for bpf_struct_ops_map_link_detach()

 - Hold update_mutex in bpf_struct_ops_link_create()

 - Add a separated instance of file_operations for links supporting
    poll.

 - Fix bpftool for bpf_link_fops_poll.

Changes from v3:

 - Add a comment to explain why holding update_mutex is not necessary
    in bpf_struct_ops_link_create()

 - Use rcu_access_pointer() in bpf_struct_ops_map_link_poll().

Changes from v2:

 - Rephrased commit logs and comments.

 - Addressed some mistakes from patch splitting.

 - Replace mutex with spinlock in bpf_testmod.c to address lockdep
    Splat and simplify the implementation.

 - Fix an argument passing to rcu_dereference_protected().

Changes from v1:

 - Pass a link to reg, unreg, and update callbacks.

 - Provide a function to detach a link from underlying subsystems.

 - Add a kfunc to mimic detachments from subsystems, and provide a
    flexible way to control when to do detachments.

 - Add two tests to detach a link from the subsystem after the refcount
    of the link drops to zero.

v6: https://lore.kernel.org/bpf/20240524223036.318800-1-thinker.li@gmail.com/
v5: https://lore.kernel.org/all/20240523230848.2022072-1-thinker.li@gmail.com/
v4: https://lore.kernel.org/all/20240521225121.770930-1-thinker.li@gmail.com/
v3: https://lore.kernel.org/all/20240510002942.1253354-1-thinker.li@gmail.com/
v2: https://lore.kernel.org/all/20240507055600.2382627-1-thinker.li@gmail.com/
v1: https://lore.kernel.org/all/20240429213609.487820-1-thinker.li@gmail.com/
====================
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

To support epoll, a new instance of file_operations, bpf_link_fops_poll,
has been added for links that support epoll. The pid_iter.bpf.c checks
f_ops for links and other BPF objects. The check should fail for struct_ops
links without this patch.
Acked-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240530065946.979330-9-thinker.li@gmail.comSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

Verify whether a user space program is informed through epoll with EPOLLHUP
when a struct_ops object is detached.

The BPF code in selftests/bpf/progs/struct_ops_module.c has become
complex. Therefore, struct_ops_detach.c has been added to segregate the BPF
code for detachment tests from the BPF code for other tests based on the
recommendation of Andrii Nakryiko.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240530065946.979330-6-thinker.li@gmail.comSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

bpf_link_inc_not_zero() will be used by kernel modules.  We will use it in
bpf_testmod.c later.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240530065946.979330-5-thinker.li@gmail.comSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

Add epoll support to bpf struct_ops links to trigger EPOLLHUP event upon
detachment.

This patch implements the "poll" of the "struct file_operations" for BPF
links and introduces a new "poll" operator in the "struct bpf_link_ops". By
implementing "poll" of "struct bpf_link_ops" for the links of struct_ops,
the file descriptor of a struct_ops link can be added to an epoll file
descriptor to receive EPOLLHUP events.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240530065946.979330-4-thinker.li@gmail.comSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

Implement the detach callback in bpf_link_ops for struct_ops so that user
programs can detach a struct_ops link. The subsystems that struct_ops
objects are registered to can also use this callback to detach the links
being passed to them.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240530065946.979330-3-thinker.li@gmail.comSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

Pass an additional pointer of bpf_struct_ops_link to callback function reg,
unreg, and update provided by subsystems defined in bpf_struct_ops. A
bpf_struct_ops_map can be registered for multiple links. Passing a pointer
of bpf_struct_ops_link helps subsystems to distinguish them.

This pointer will be used in the later patches to let the subsystem
initiate a detachment on a link that was registered to it previously.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240530065946.979330-2-thinker.li@gmail.comSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

libbpf can deduce program type and attach type from the ELF section name.
We don't need to pass it out-of-band if we switch to libbpf convention [1].

[1] https://docs.kernel.org/bpf/libbpf/program_types.htmlSigned-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240522080936.2475833-1-jakub@cloudflare.com

Yafang Shao says:

====================
bpf: Add a generic bits iterator

Three new kfuncs, namely bpf_iter_bits_{new,next,destroy}, have been
added for the new bpf_iter_bits functionality. These kfuncs enable the
iteration of the bits from a given address and a given number of bits.

- bpf_iter_bits_new
  Initialize a new bits iterator for a given memory area. Due to the
  limitation of bpf memalloc, the max number of bits to be iterated
  over is (4096 * 8).
- bpf_iter_bits_next
  Get the next bit in a bpf_iter_bits
- bpf_iter_bits_destroy
  Destroy a bpf_iter_bits

The bits iterator can be used in any context and on any address.

Changes:
- v7->v8:
  Refine the interface to avoid dealing with endianness (Andrii)
- v6->v7:
  Fix endianness error for non-long-aligned data (Andrii)
- v5->v6:
  Add positive tests (Andrii)
- v4->v5:
  Simplify test cases (Andrii)
- v3->v4:
  - Fix endianness error on s390x (Andrii)
  - zero-initialize kit->bits_copy and zero out nr_bits (Andrii)
- v2->v3:
  Optimization for u64/u32 mask (Andrii)
- v1->v2:
  Simplify the CPU number verification code to avoid the failure on s390x
  (Eduard)
- bpf: Add bpf_iter_cpumask
  https://lwn.net/Articles/961104/
- bpf: Add new bpf helper bpf_for_each_cpu
  https://lwn.net/Articles/939939/
====================

Link: https://lore.kernel.org/r/20240517023034.48138-1-laoar.shao@gmail.comSigned-off-by: Andrii Nakryiko <andrii@kernel.org>

Add test cases for the bits iter:

- Positive cases
  - Bit mask representing a single word (8-byte unit)
  - Bit mask representing data spanning more than one word
  - The index of the set bit

- Nagative cases
  - bpf_iter_bits_destroy() is required after calling
    bpf_iter_bits_new()
  - bpf_iter_bits_destroy() can only destroy an initialized iter
  - bpf_iter_bits_next() must use an initialized iter
  - Bit mask representing zero words
  - Bit mask representing fewer words than expected
  - Case for ENOMEM
  - Case for NULL pointer
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240517023034.48138-3-laoar.shao@gmail.com

Add three new kfuncs for the bits iterator:
- bpf_iter_bits_new
  Initialize a new bits iterator for a given memory area. Due to the
  limitation of bpf memalloc, the max number of words (8-byte units) that
  can be iterated over is limited to (4096 / 8).
- bpf_iter_bits_next
  Get the next bit in a bpf_iter_bits
- bpf_iter_bits_destroy
  Destroy a bpf_iter_bits

The bits iterator facilitates the iteration of the bits of a memory area,
such as cpumask. It can be used in any context and on any address.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240517023034.48138-2-laoar.shao@gmail.com

Geliang Tang says:

====================
This patchset uses post_socket_cb callbacks of struct network_helper_opts
to refactor do_test() in bpf_tcp_ca.c.

v5:
 - address Martin's comments in v4 (thanks)
 - add patch 4, use start_server_str in test_dctcp_fallback too
 - ASSERT_* is already used in settcpca, use this helper in cc_cb (patch 3).

v4:
 - address Martin's comments in v3 (thanks).
 - drop 2 patches, keep "type" as the individual arg to start_server_addr,
   connect_to_addr and start_server_str.

v3:
 - Add 4 new patches, 1-3 are cleanups. 4 adds a new helper.
 - address Martin's comments in v2.

v2:
 - rebased on commit "selftests/bpf: Add test for the use of new args in
 cong_control"
====================
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

This patch uses new helper start_server_str() in do_test() in bpf_tcp_ca.c
to accept a struct network_helper_opts argument instead of using
start_server() and settcpca(). Then change the type of the first paramenter
of do_test() into a struct network_helper_opts one.

Define its own cb_opts and opts for each test, set its own cc name into
cb_opts.cc, and cc_cb() into post_socket_cb callback, then pass it to
do_test().
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Link: https://lore.kernel.org/r/6e1b6555e3284e77c8aa60668c61a66c5f99aa37.1716638248.git.tanggeliang@kylinos.cnSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

This patch uses start_server_str() helper in test_dctcp_fallback() in
bpf_tcp_ca.c, instead of using start_server() and settcpca(). For
support opts in start_server_str() helper, opts->cb_opts needs to be
passed to post_socket_cb() in __start_server().
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Link: https://lore.kernel.org/r/414c749321fa150435f7fe8e12c80fec8b447c78.1716638248.git.tanggeliang@kylinos.cnSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

Since the post_socket_cb() callback is added in struct network_helper_opts,
it's make sense to use it not only in __start_server(), but also in
connect_to_fd_opts(). Then it can be used to set TCP_CONGESTION sockopt.

Add a "void *" type member cb_opts into struct network_helper_opts, and add
a new struct named cb_opts in prog_tests/bpf_tcp_ca.c, then cc can be moved
into struct cb_opts from network_helper_opts. Define a new callback cc_cb()
to set TCP_CONGESTION sockopt, and set it to post_socket_cb pointer of opts.
Define a new cb_opts cubic, set it to cb_opts of opts. Pass this opts to
connect_to_fd_opts() in test_dctcp_fallback().
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Link: https://lore.kernel.org/r/b512bb8d8f6854c9ea5c409b69d1bf37c6f272c6.1716638248.git.tanggeliang@kylinos.cnSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

It's a tech debt that start_server() does not take the "opts" argument.
It's pretty handy to have start_server() as a helper that takes string
address.

So this patch creates a new helper start_server_str(). Then start_server()
can be a wrapper of it.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Link: https://lore.kernel.org/r/606e6cfd7e1aff8bc51ede49862eed0802e52170.1716638248.git.tanggeliang@kylinos.cnSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

It's not possible to have one generic/common "struct post_socket_opts"
for all tests. It's better to have the individual test define its own
callback opts struct.

So this patch drops struct post_socket_opts, and changes the second
parameter of post_socket_cb as "void *" type.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Link: https://lore.kernel.org/r/f8bda41c7cb9cb6979b2779f89fb3a684234304f.1716638248.git.tanggeliang@kylinos.cnSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

Configure logging verbosity by setting LIBBPF_LOG_LEVEL environment
variable, which is applied only to default logger. Once user set their
custom logging callback, it is up to them to handle filtering.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240524131840.114289-1-yatsenko@meta.com

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-05-28

We've added 23 non-merge commits during the last 11 day(s) which contain
a total of 45 files changed, 696 insertions(+), 277 deletions(-).

The main changes are:

1) Rename skb's mono_delivery_time to tstamp_type for extensibility
   and add SKB_CLOCK_TAI type support to bpf_skb_set_tstamp(),
   from Abhishek Chauhan.

2) Add netfilter CT zone ID and direction to bpf_ct_opts so that arbitrary
   CT zones can be used from XDP/tc BPF netfilter CT helper functions,
   from Brad Cowie.

3) Several tweaks to the instruction-set.rst IETF doc to address
   the Last Call review comments, from Dave Thaler.

4) Small batch of riscv64 BPF JIT optimizations in order to emit more
   compressed instructions to the JITed image for better icache efficiency,
   from Xiao Wang.

5) Sort bpftool C dump output from BTF, aiming to simplify vmlinux.h
   diffing and forcing more natural type definitions ordering,
   from Mykyta Yatsenko.

6) Use DEV_STATS_INC() macro in BPF redirect helpers to silence
   a syzbot/KCSAN race report for the tx_errors counter,
   from Jiang Yunshui.

7) Un-constify bpf_func_info in bpftool to fix compilation with LLVM 17+
   which started treating const structs as constants and thus breaking
   full BTF program name resolution, from Ivan Babrou.

8) Fix up BPF program numbers in test_sockmap selftest in order to reduce
   some of the test-internal array sizes, from Geliang Tang.

9) Small cleanup in Makefile.btf script to use test-ge check for v1.25-only
   pahole, from Alan Maguire.

10) Fix bpftool's make dependencies for vmlinux.h in order to avoid needless
    rebuilds in some corner cases, from Artem Savkov.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (23 commits)
  bpf, net: Use DEV_STAT_INC()
  bpf, docs: Fix instruction.rst indentation
  bpf, docs: Clarify call local offset
  bpf, docs: Add table captions
  bpf, docs: clarify sign extension of 64-bit use of 32-bit imm
  bpf, docs: Use RFC 2119 language for ISA requirements
  bpf, docs: Move sentence about returning R0 to abi.rst
  bpf: constify member bpf_sysctl_kern:: Table
  riscv, bpf: Try RVC for reg move within BPF_CMPXCHG JIT
  riscv, bpf: Use STACK_ALIGN macro for size rounding up
  riscv, bpf: Optimize zextw insn with Zba extension
  selftests/bpf: Handle forwarding of UDP CLOCK_TAI packets
  net: Add additional bit to support clockid_t timestamp type
  net: Rename mono_delivery_time to tstamp_type for scalabilty
  selftests/bpf: Update tests for new ct zone opts for nf_conntrack kfuncs
  net: netfilter: Make ct zone opts configurable for bpf ct helpers
  selftests/bpf: Fix prog numbers in test_sockmap
  bpf: Remove unused variable "prev_state"
  bpftool: Un-const bpf_func_info to fix it for llvm 17 and newer
  bpf: Fix order of args in call to bpf_map_kvcalloc
  ...
====================

Link: https://lore.kernel.org/r/20240528105924.30905-1-daniel@iogearbox.netSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Both lan78xx and smsc75xx have a 'usb_context'
struct which is unused, since their original commits.

Remove them.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Link: https://lore.kernel.org/r/20240526205922.176578-1-linux@treblig.orgSigned-off-by: Paolo Abeni <pabeni@redhat.com>

'ne2k_pci_card' is unused since 2.3.99-pre3 in March 2000.

Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

'mlx4_port_config was added by
commit ab9c17a0 ("mlx4_core: Modify driver initialization flow to
accommodate SRIOV for Ethernet")
but remained unused.

Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

'niclist' and 'oct_link_status_resp' are unused since the original
commit f21fb3ed ("Add support of Cavium Liquidio ethernet
adapters").

Remove them.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

'short_rx_done_desc' and 'basic_rx_done_desc' are unused since
commit fdecea66 ("  [netdrvr starfire] Add GPL'd firmware, remove
compat code").

Remove them.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

In commit cdfbabfb ("net: Work around lockdep limitation in
sockets that use sockets"), it introduces 'af_kern_callback_keys'
to lockdep-init of sk_callback_lock according to 'sk_kern_sock',
it modifies sock_init_data() only, and sk_clone_lock() calls
sk_init_common() to initialize sk_callback_lock too, so the
lockdep-init of sk_callback_lock should be moved to sk_init_common().
Signed-off-by: Gou Hao <gouhao@uniontech.com>
Link: https://lore.kernel.org/r/20240526145718.9542-2-gouhao@uniontech.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

sk_callback_lock has already been initialized in sk_init_common().
Signed-off-by: Gou Hao <gouhao@uniontech.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240526145718.9542-1-gouhao@uniontech.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

syzbot/KCSAN reported that races happen when multiple CPUs updating
dev->stats.tx_error concurrently. Adopt SMP safe DEV_STATS_INC() to
update the dev->stats fields.
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: yunshui <jiangyunshui@kylinos.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240523033520.4029314-1-jiangyunshui@kylinos.cn

'bf_ctx' appears unused since the original
commit 960366cf ("Add mISDN DSP").

Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Link: https://lore.kernel.org/r/20240523155922.67329-1-linux@treblig.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The table captions patch corrected indented most tables to work with
the table directive for adding a caption but missed two of them.
Signed-off-by: Dave Thaler <dthaler1968@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240526061815.22497-1-dthaler1968@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

In the Jump instructions section it explains that the offset is
"relative to the instruction following the jump instruction".
But the program-local section confusingly said "referenced by
offset from the call instruction, similar to JA".

This patch updates that sentence with consistent wording, saying
it's relative to the instruction following the call instruction.
Signed-off-by: Dave Thaler <dthaler1968@gmail.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240525153332.21355-1-dthaler1968@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

As suggested by Ines Robles in his IETF GENART review at
https://datatracker.ietf.org/doc/review-ietf-bpf-isa-02-genart-lc-robles-2024-05-16/Signed-off-by: Dave Thaler <dthaler1968@gmail.com>
Link: https://lore.kernel.org/r/20240524164618.18894-1-dthaler1968@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

imm is defined as a 32-bit signed integer.

{MOV, K, ALU64} says it does "dst = src" (where src is 'imm') and it
does do dst = (s64)imm, which in that sense does sign extend imm. The MOVSX
instruction is explained as sign extending, so added the example of
{MOV, K, ALU64} to make this more clear.

{JLE, K, JMP} says it does "PC += offset if dst <= src" (where src is 'imm',
and the comparison is unsigned). This was apparently ambiguous to some
readers as to whether the comparison was "dst <= (u64)(u32)imm" or
"dst <= (u64)(s64)imm" so added an example to make this more clear.

v1 -> v2: Address comments from Yonghong
Signed-off-by: Dave Thaler <dthaler1968@googlemail.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20240520215255.10595-1-dthaler1968@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Per IETF convention and discussion at LSF/MM/BPF, use MUST etc.
keywords as requested by IETF Area Director review.  Also as
requested, indicate that documenting BTF is out of scope of this
document and will be covered by a separate IETF specification.

Added paragraph about the terminology that is required IETF boilerplate
and must be worded exactly as such.
Signed-off-by: Dave Thaler <dthaler1968@googlemail.com>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20240517165855.4688-1-dthaler1968@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

As discussed at LSF/MM/BPF, the sentence about using R0 for returning
values from calls is part of the calling convention and belongs in
abi.rst.  Any further additions or clarifications to this text are left
for future patches on abi.rst.  The current patch is simply to unblock
progression of instruction-set.rst to a standard.

In contrast, the restriction of register numbers to the range 0-10
is untouched, left in the instruction-set.rst definition of the
src_reg and dst_reg fields.
Signed-off-by: Dave Thaler <dthaler1968@googlemail.com>
Link: https://lore.kernel.org/r/20240517153445.3914-1-dthaler1968@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

The sysctl core is preparing to only expose instances of struct ctl_table
as "const". This will also affect the ctl_table argument of sysctl handlers,
for which bpf_sysctl_kern::table is also used.

As the function prototype of all sysctl handlers throughout the tree
needs to stay consistent that change will be done in one commit.

To reduce the size of that final commit, switch this utility type which
is not bound by "typedef proc_handler" to "const struct ctl_table".

No functional change.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Joel Granados <j.granados@samsung.com>
Link: https://lore.kernel.org/bpf/20240518-sysctl-const-handler-bpf-v1-1-f0d7186743c1@weissschuh.net