<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/kernel/bpf/btf.c, branch v6.16.2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Merge tag 'bpf-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next</title>
<updated>2025-05-28T22:52:42+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-05-28T22:52:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=90b83efa6701656e02c86e7df2cb1765ea602d07'/>
<id>90b83efa6701656e02c86e7df2cb1765ea602d07</id>
<content type='text'>
Pull bpf updates from Alexei Starovoitov:

 - Fix and improve BTF deduplication of identical BTF types (Alan
   Maguire and Andrii Nakryiko)

 - Support up to 12 arguments in BPF trampoline on arm64 (Xu Kuohai and
   Alexis Lothoré)

 - Support load-acquire and store-release instructions in BPF JIT on
   riscv64 (Andrea Parri)

 - Fix uninitialized values in BPF_{CORE,PROBE}_READ macros (Anton
   Protopopov)

 - Streamline allowed helpers across program types (Feng Yang)

 - Support atomic update for hashtab of BPF maps (Hou Tao)

 - Implement json output for BPF helpers (Ihor Solodrai)

 - Several s390 JIT fixes (Ilya Leoshkevich)

 - Various sockmap fixes (Jiayuan Chen)

 - Support mmap of vmlinux BTF data (Lorenz Bauer)

 - Support BPF rbtree traversal and list peeking (Martin KaFai Lau)

 - Tests for sockmap/sockhash redirection (Michal Luczaj)

 - Introduce kfuncs for memory reads into dynptrs (Mykyta Yatsenko)

 - Add support for dma-buf iterators in BPF (T.J. Mercier)

 - The verifier support for __bpf_trap() (Yonghong Song)

* tag 'bpf-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (135 commits)
  bpf, arm64: Remove unused-but-set function and variable.
  selftests/bpf: Add tests with stack ptr register in conditional jmp
  bpf: Do not include stack ptr register in precision backtracking bookkeeping
  selftests/bpf: enable many-args tests for arm64
  bpf, arm64: Support up to 12 function arguments
  bpf: Check rcu_read_lock_trace_held() in bpf_map_lookup_percpu_elem()
  bpf: Avoid __bpf_prog_ret0_warn when jit fails
  bpftool: Add support for custom BTF path in prog load/loadall
  selftests/bpf: Add unit tests with __bpf_trap() kfunc
  bpf: Warn with __bpf_trap() kfunc maybe due to uninitialized variable
  bpf: Remove special_kfunc_set from verifier
  selftests/bpf: Add test for open coded dmabuf_iter
  selftests/bpf: Add test for dmabuf_iter
  bpf: Add open coded dmabuf iterator
  bpf: Add dmabuf iterator
  dma-buf: Rename debugfs symbols
  bpf: Fix error return value in bpf_copy_from_user_dynptr
  libbpf: Use mmap to parse vmlinux BTF from sysfs
  selftests: bpf: Add a test for mmapable vmlinux BTF
  btf: Allow mmap of vmlinux btf
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull bpf updates from Alexei Starovoitov:

 - Fix and improve BTF deduplication of identical BTF types (Alan
   Maguire and Andrii Nakryiko)

 - Support up to 12 arguments in BPF trampoline on arm64 (Xu Kuohai and
   Alexis Lothoré)

 - Support load-acquire and store-release instructions in BPF JIT on
   riscv64 (Andrea Parri)

 - Fix uninitialized values in BPF_{CORE,PROBE}_READ macros (Anton
   Protopopov)

 - Streamline allowed helpers across program types (Feng Yang)

 - Support atomic update for hashtab of BPF maps (Hou Tao)

 - Implement json output for BPF helpers (Ihor Solodrai)

 - Several s390 JIT fixes (Ilya Leoshkevich)

 - Various sockmap fixes (Jiayuan Chen)

 - Support mmap of vmlinux BTF data (Lorenz Bauer)

 - Support BPF rbtree traversal and list peeking (Martin KaFai Lau)

 - Tests for sockmap/sockhash redirection (Michal Luczaj)

 - Introduce kfuncs for memory reads into dynptrs (Mykyta Yatsenko)

 - Add support for dma-buf iterators in BPF (T.J. Mercier)

 - The verifier support for __bpf_trap() (Yonghong Song)

* tag 'bpf-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (135 commits)
  bpf, arm64: Remove unused-but-set function and variable.
  selftests/bpf: Add tests with stack ptr register in conditional jmp
  bpf: Do not include stack ptr register in precision backtracking bookkeeping
  selftests/bpf: enable many-args tests for arm64
  bpf, arm64: Support up to 12 function arguments
  bpf: Check rcu_read_lock_trace_held() in bpf_map_lookup_percpu_elem()
  bpf: Avoid __bpf_prog_ret0_warn when jit fails
  bpftool: Add support for custom BTF path in prog load/loadall
  selftests/bpf: Add unit tests with __bpf_trap() kfunc
  bpf: Warn with __bpf_trap() kfunc maybe due to uninitialized variable
  bpf: Remove special_kfunc_set from verifier
  selftests/bpf: Add test for open coded dmabuf_iter
  selftests/bpf: Add test for dmabuf_iter
  bpf: Add open coded dmabuf iterator
  bpf: Add dmabuf iterator
  dma-buf: Rename debugfs symbols
  bpf: Fix error return value in bpf_copy_from_user_dynptr
  libbpf: Use mmap to parse vmlinux BTF from sysfs
  selftests: bpf: Add a test for mmapable vmlinux BTF
  btf: Allow mmap of vmlinux btf
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: WARN_ONCE on verifier bugs</title>
<updated>2025-05-19T15:17:08+00:00</updated>
<author>
<name>Paul Chaignon</name>
<email>paul.chaignon@gmail.com</email>
</author>
<published>2025-05-19T13:43:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1cb0f56d96185cb20e63e191fc291191823e6f52'/>
<id>1cb0f56d96185cb20e63e191fc291191823e6f52</id>
<content type='text'>
Throughout the verifier's logic, there are multiple checks for
inconsistent states that should never happen and would indicate a
verifier bug. These bugs are typically logged in the verifier logs and
sometimes preceded by a WARN_ONCE.

This patch reworks these checks to consistently emit a verifier log AND
a warning when CONFIG_DEBUG_KERNEL is enabled. The consistent use of
WARN_ONCE should help fuzzers (ex. syzkaller) expose any situation
where they are actually able to reach one of those buggy verifier
states.

Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Paul Chaignon &lt;paul.chaignon@gmail.com&gt;
Link: https://lore.kernel.org/r/aCs1nYvNNMq8dAWP@mail.gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Throughout the verifier's logic, there are multiple checks for
inconsistent states that should never happen and would indicate a
verifier bug. These bugs are typically logged in the verifier logs and
sometimes preceded by a WARN_ONCE.

This patch reworks these checks to consistently emit a verifier log AND
a warning when CONFIG_DEBUG_KERNEL is enabled. The consistent use of
WARN_ONCE should help fuzzers (ex. syzkaller) expose any situation
where they are actually able to reach one of those buggy verifier
states.

Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Paul Chaignon &lt;paul.chaignon@gmail.com&gt;
Link: https://lore.kernel.org/r/aCs1nYvNNMq8dAWP@mail.gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Replace offsetof() with struct_size()</title>
<updated>2025-05-05T21:21:46+00:00</updated>
<author>
<name>Thorsten Blum</name>
<email>thorsten.blum@linux.dev</email>
</author>
<published>2025-05-03T15:15:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=41948afcf503b5667637a0b3ab279a061f559bec'/>
<id>41948afcf503b5667637a0b3ab279a061f559bec</id>
<content type='text'>
Compared to offsetof(), struct_size() provides additional compile-time
checks for structs with flexible arrays (e.g., __must_be_array()).

No functional changes intended.

Signed-off-by: Thorsten Blum &lt;thorsten.blum@linux.dev&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250503151513.343931-2-thorsten.blum@linux.dev
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Compared to offsetof(), struct_size() provides additional compile-time
checks for structs with flexible arrays (e.g., __must_be_array()).

No functional changes intended.

Signed-off-by: Thorsten Blum &lt;thorsten.blum@linux.dev&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250503151513.343931-2-thorsten.blum@linux.dev
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Allow access to const void pointer arguments in tracing programs</title>
<updated>2025-04-23T18:26:15+00:00</updated>
<author>
<name>KaFai Wan</name>
<email>mannkafai@gmail.com</email>
</author>
<published>2025-04-23T12:13:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1271a40eeafa8e9b5b76c4d02e2b3812cbc3c280'/>
<id>1271a40eeafa8e9b5b76c4d02e2b3812cbc3c280</id>
<content type='text'>
Adding support to access arguments with const void pointer arguments
in tracing programs.

Currently we allow tracing programs to access void pointers. If we try to
access argument which is pointer to const void like 2nd argument in kfree,
verifier will fail to load the program with;

0: R1=ctx() R10=fp0
; asm volatile ("r2 = *(u64 *)(r1 + 8); ");
0: (79) r2 = *(u64 *)(r1 +8)
func 'kfree' arg1 type UNKNOWN is not a struct

Changing the is_int_ptr to void and generic integer check and renaming
it to is_void_or_int_ptr.

Signed-off-by: KaFai Wan &lt;mannkafai@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250423121329.3163461-2-mannkafai@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Adding support to access arguments with const void pointer arguments
in tracing programs.

Currently we allow tracing programs to access void pointers. If we try to
access argument which is pointer to const void like 2nd argument in kfree,
verifier will fail to load the program with;

0: R1=ctx() R10=fp0
; asm volatile ("r2 = *(u64 *)(r1 + 8); ");
0: (79) r2 = *(u64 *)(r1 +8)
func 'kfree' arg1 type UNKNOWN is not a struct

Changing the is_int_ptr to void and generic integer check and renaming
it to is_void_or_int_ptr.

Signed-off-by: KaFai Wan &lt;mannkafai@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250423121329.3163461-2-mannkafai@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Use proper type to calculate bpf_raw_tp_null_args.mask index</title>
<updated>2025-04-23T17:21:24+00:00</updated>
<author>
<name>Shung-Hsi Yu</name>
<email>shung-hsi.yu@suse.com</email>
</author>
<published>2025-04-18T07:49:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=53ebef53a657d7957d35dc2b953db64f1bb28065'/>
<id>53ebef53a657d7957d35dc2b953db64f1bb28065</id>
<content type='text'>
The calculation of the index used to access the mask field in 'struct
bpf_raw_tp_null_args' is done with 'int' type, which could overflow when
the tracepoint being attached has more than 8 arguments.

While none of the tracepoints mentioned in raw_tp_null_args[] currently
have more than 8 arguments, there do exist tracepoints that had more
than 8 arguments (e.g. iocost_iocg_forgive_debt), so use the correct
type for calculation and avoid Smatch static checker warning.

Reported-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Signed-off-by: Shung-Hsi Yu &lt;shung-hsi.yu@suse.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Link: https://lore.kernel.org/bpf/20250418074946.35569-1-shung-hsi.yu@suse.com

Closes: https://lore.kernel.org/r/843a3b94-d53d-42db-93d4-be10a4090146@stanley.mountain/
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The calculation of the index used to access the mask field in 'struct
bpf_raw_tp_null_args' is done with 'int' type, which could overflow when
the tracepoint being attached has more than 8 arguments.

While none of the tracepoints mentioned in raw_tp_null_args[] currently
have more than 8 arguments, there do exist tracepoints that had more
than 8 arguments (e.g. iocost_iocg_forgive_debt), so use the correct
type for calculation and avoid Smatch static checker warning.

Reported-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Signed-off-by: Shung-Hsi Yu &lt;shung-hsi.yu@suse.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Link: https://lore.kernel.org/bpf/20250418074946.35569-1-shung-hsi.yu@suse.com

Closes: https://lore.kernel.org/r/843a3b94-d53d-42db-93d4-be10a4090146@stanley.mountain/
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next</title>
<updated>2025-04-22T01:51:08+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2025-04-22T01:51:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=07e32237ed9d3f5815fb900dee9458b5f115a678'/>
<id>07e32237ed9d3f5815fb900dee9458b5f115a678</id>
<content type='text'>
Martin KaFai Lau says:

====================
pull-request: bpf-next 2025-04-17

We've added 12 non-merge commits during the last 9 day(s) which contain
a total of 18 files changed, 1748 insertions(+), 19 deletions(-).

The main changes are:

1) bpf qdisc support, from Amery Hung.
   A qdisc can be implemented in bpf struct_ops programs and
   can be used the same as other existing qdiscs in the
   "tc qdisc" command.

2) Add xsk tail adjustment tests, from Tushar Vyavahare.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
  selftests/bpf: Test attaching bpf qdisc to mq and non root
  selftests/bpf: Add a bpf fq qdisc to selftest
  selftests/bpf: Add a basic fifo qdisc test
  libbpf: Support creating and destroying qdisc
  bpf: net_sched: Disable attaching bpf qdisc to non root
  bpf: net_sched: Support updating bstats
  bpf: net_sched: Add a qdisc watchdog timer
  bpf: net_sched: Add basic bpf qdisc kfuncs
  bpf: net_sched: Support implementation of Qdisc_ops in bpf
  bpf: Prepare to reuse get_ctx_arg_idx
  selftests/xsk: Add tail adjustment tests and support check
  selftests/xsk: Add packet stream replacement function
====================

Link: https://patch.msgid.link/20250417184338.3152168-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Martin KaFai Lau says:

====================
pull-request: bpf-next 2025-04-17

We've added 12 non-merge commits during the last 9 day(s) which contain
a total of 18 files changed, 1748 insertions(+), 19 deletions(-).

The main changes are:

1) bpf qdisc support, from Amery Hung.
   A qdisc can be implemented in bpf struct_ops programs and
   can be used the same as other existing qdiscs in the
   "tc qdisc" command.

2) Add xsk tail adjustment tests, from Tushar Vyavahare.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
  selftests/bpf: Test attaching bpf qdisc to mq and non root
  selftests/bpf: Add a bpf fq qdisc to selftest
  selftests/bpf: Add a basic fifo qdisc test
  libbpf: Support creating and destroying qdisc
  bpf: net_sched: Disable attaching bpf qdisc to non root
  bpf: net_sched: Support updating bstats
  bpf: net_sched: Add a qdisc watchdog timer
  bpf: net_sched: Add basic bpf qdisc kfuncs
  bpf: net_sched: Support implementation of Qdisc_ops in bpf
  bpf: Prepare to reuse get_ctx_arg_idx
  selftests/xsk: Add tail adjustment tests and support check
  selftests/xsk: Add packet stream replacement function
====================

Link: https://patch.msgid.link/20250417184338.3152168-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Prepare to reuse get_ctx_arg_idx</title>
<updated>2025-04-17T17:50:55+00:00</updated>
<author>
<name>Amery Hung</name>
<email>ameryhung@gmail.com</email>
</author>
<published>2025-04-09T21:45:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a1b669ea16c4d7c1a1a8fc7e25aaf651ea0078c3'/>
<id>a1b669ea16c4d7c1a1a8fc7e25aaf651ea0078c3</id>
<content type='text'>
Rename get_ctx_arg_idx to bpf_ctx_arg_idx, and allow others to call it.
No functional change.

Signed-off-by: Amery Hung &lt;ameryhung@gmail.com&gt;
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Acked-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Link: https://patch.msgid.link/20250409214606.2000194-2-ameryhung@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Rename get_ctx_arg_idx to bpf_ctx_arg_idx, and allow others to call it.
No functional change.

Signed-off-by: Amery Hung &lt;ameryhung@gmail.com&gt;
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Acked-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Link: https://patch.msgid.link/20250409214606.2000194-2-ameryhung@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>trace: tcp: Add tracepoint for tcp_sendmsg_locked()</title>
<updated>2025-04-11T01:34:05+00:00</updated>
<author>
<name>Breno Leitao</name>
<email>leitao@debian.org</email>
</author>
<published>2025-04-08T18:32:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0f08335ade71273f89d19412268b48b55f3e3726'/>
<id>0f08335ade71273f89d19412268b48b55f3e3726</id>
<content type='text'>
Add a tracepoint to monitor TCP send operations, enabling detailed
visibility into TCP message transmission.

Create a new tracepoint within the tcp_sendmsg_locked function,
capturing traditional fields along with size_goal, which indicates the
optimal data size for a single TCP segment. Additionally, a reference to
the struct sock sk is passed, allowing direct access for BPF programs.
The implementation is largely based on David's patch[1] and suggestions.

Link: https://lore.kernel.org/all/70168c8f-bf52-4279-b4c4-be64527aa1ac@kernel.org/ [1]
Signed-off-by: Breno Leitao &lt;leitao@debian.org&gt;
Reviewed-by: David Ahern &lt;dsahern@kernel.org&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@amazon.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Link: https://patch.msgid.link/20250408-tcpsendmsg-v3-2-208b87064c28@debian.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add a tracepoint to monitor TCP send operations, enabling detailed
visibility into TCP message transmission.

Create a new tracepoint within the tcp_sendmsg_locked function,
capturing traditional fields along with size_goal, which indicates the
optimal data size for a single TCP segment. Additionally, a reference to
the struct sock sk is passed, allowing direct access for BPF programs.
The implementation is largely based on David's patch[1] and suggestions.

Link: https://lore.kernel.org/all/70168c8f-bf52-4279-b4c4-be64527aa1ac@kernel.org/ [1]
Signed-off-by: Breno Leitao &lt;leitao@debian.org&gt;
Reviewed-by: David Ahern &lt;dsahern@kernel.org&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@amazon.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Link: https://patch.msgid.link/20250408-tcpsendmsg-v3-2-208b87064c28@debian.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'bpf_res_spin_lock' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next</title>
<updated>2025-03-30T20:06:27+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-03-30T20:06:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=494e7fe591bf834d57c6607cdc26ab8873708aa7'/>
<id>494e7fe591bf834d57c6607cdc26ab8873708aa7</id>
<content type='text'>
Pull bpf relisient spinlock support from Alexei Starovoitov:
 "This patch set introduces Resilient Queued Spin Lock (or rqspinlock
  with res_spin_lock() and res_spin_unlock() APIs).

  This is a qspinlock variant which recovers the kernel from a stalled
  state when the lock acquisition path cannot make forward progress.
  This can occur when a lock acquisition attempt enters a deadlock
  situation (e.g. AA, or ABBA), or more generally, when the owner of the
  lock (which we’re trying to acquire) isn’t making forward progress.
  Deadlock detection is the main mechanism used to provide instant
  recovery, with the timeout mechanism acting as a final line of
  defense. Detection is triggered immediately when beginning the waiting
  loop of a lock slow path.

  Additionally, BPF programs attached to different parts of the kernel
  can introduce new control flow into the kernel, which increases the
  likelihood of deadlocks in code not written to handle reentrancy.
  There have been multiple syzbot reports surfacing deadlocks in
  internal kernel code due to the diverse ways in which BPF programs can
  be attached to different parts of the kernel. By switching the BPF
  subsystem’s lock usage to rqspinlock, all of these issues are
  mitigated at runtime.

  This spin lock implementation allows BPF maps to become safer and
  remove mechanisms that have fallen short in assuring safety when
  nesting programs in arbitrary ways in the same context or across
  different contexts.

  We run benchmarks that stress locking scalability and perform
  comparison against the baseline (qspinlock). For the rqspinlock case,
  we replace the default qspinlock with it in the kernel, such that all
  spin locks in the kernel use the rqspinlock slow path. As such,
  benchmarks that stress kernel spin locks end up exercising rqspinlock.

  More details in the cover letter in commit 6ffb9017e932 ("Merge branch
  'resilient-queued-spin-lock'")"

* tag 'bpf_res_spin_lock' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (24 commits)
  selftests/bpf: Add tests for rqspinlock
  bpf: Maintain FIFO property for rqspinlock unlock
  bpf: Implement verifier support for rqspinlock
  bpf: Introduce rqspinlock kfuncs
  bpf: Convert lpm_trie.c to rqspinlock
  bpf: Convert percpu_freelist.c to rqspinlock
  bpf: Convert hashtab.c to rqspinlock
  rqspinlock: Add locktorture support
  rqspinlock: Add entry to Makefile, MAINTAINERS
  rqspinlock: Add macros for rqspinlock usage
  rqspinlock: Add basic support for CONFIG_PARAVIRT
  rqspinlock: Add a test-and-set fallback
  rqspinlock: Add deadlock detection and recovery
  rqspinlock: Protect waiters in trylock fallback from stalls
  rqspinlock: Protect waiters in queue from stalls
  rqspinlock: Protect pending bit owners from stalls
  rqspinlock: Hardcode cond_acquire loops for arm64
  rqspinlock: Add support for timeouts
  rqspinlock: Drop PV and virtualization support
  rqspinlock: Add rqspinlock.h header
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull bpf relisient spinlock support from Alexei Starovoitov:
 "This patch set introduces Resilient Queued Spin Lock (or rqspinlock
  with res_spin_lock() and res_spin_unlock() APIs).

  This is a qspinlock variant which recovers the kernel from a stalled
  state when the lock acquisition path cannot make forward progress.
  This can occur when a lock acquisition attempt enters a deadlock
  situation (e.g. AA, or ABBA), or more generally, when the owner of the
  lock (which we’re trying to acquire) isn’t making forward progress.
  Deadlock detection is the main mechanism used to provide instant
  recovery, with the timeout mechanism acting as a final line of
  defense. Detection is triggered immediately when beginning the waiting
  loop of a lock slow path.

  Additionally, BPF programs attached to different parts of the kernel
  can introduce new control flow into the kernel, which increases the
  likelihood of deadlocks in code not written to handle reentrancy.
  There have been multiple syzbot reports surfacing deadlocks in
  internal kernel code due to the diverse ways in which BPF programs can
  be attached to different parts of the kernel. By switching the BPF
  subsystem’s lock usage to rqspinlock, all of these issues are
  mitigated at runtime.

  This spin lock implementation allows BPF maps to become safer and
  remove mechanisms that have fallen short in assuring safety when
  nesting programs in arbitrary ways in the same context or across
  different contexts.

  We run benchmarks that stress locking scalability and perform
  comparison against the baseline (qspinlock). For the rqspinlock case,
  we replace the default qspinlock with it in the kernel, such that all
  spin locks in the kernel use the rqspinlock slow path. As such,
  benchmarks that stress kernel spin locks end up exercising rqspinlock.

  More details in the cover letter in commit 6ffb9017e932 ("Merge branch
  'resilient-queued-spin-lock'")"

* tag 'bpf_res_spin_lock' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (24 commits)
  selftests/bpf: Add tests for rqspinlock
  bpf: Maintain FIFO property for rqspinlock unlock
  bpf: Implement verifier support for rqspinlock
  bpf: Introduce rqspinlock kfuncs
  bpf: Convert lpm_trie.c to rqspinlock
  bpf: Convert percpu_freelist.c to rqspinlock
  bpf: Convert hashtab.c to rqspinlock
  rqspinlock: Add locktorture support
  rqspinlock: Add entry to Makefile, MAINTAINERS
  rqspinlock: Add macros for rqspinlock usage
  rqspinlock: Add basic support for CONFIG_PARAVIRT
  rqspinlock: Add a test-and-set fallback
  rqspinlock: Add deadlock detection and recovery
  rqspinlock: Protect waiters in trylock fallback from stalls
  rqspinlock: Protect waiters in queue from stalls
  rqspinlock: Protect pending bit owners from stalls
  rqspinlock: Hardcode cond_acquire loops for arm64
  rqspinlock: Add support for timeouts
  rqspinlock: Drop PV and virtualization support
  rqspinlock: Add rqspinlock.h header
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'bpf-next-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next</title>
<updated>2025-03-30T19:43:03+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-03-30T19:43:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fa593d0f969dcfa41d390822fdf1a0ab48cd882c'/>
<id>fa593d0f969dcfa41d390822fdf1a0ab48cd882c</id>
<content type='text'>
Pull bpf updates from Alexei Starovoitov:
 "For this merge window we're splitting BPF pull request into three for
  higher visibility: main changes, res_spin_lock, try_alloc_pages.

  These are the main BPF changes:

   - Add DFA-based live registers analysis to improve verification of
     programs with loops (Eduard Zingerman)

   - Introduce load_acquire and store_release BPF instructions and add
     x86, arm64 JIT support (Peilin Ye)

   - Fix loop detection logic in the verifier (Eduard Zingerman)

   - Drop unnecesary lock in bpf_map_inc_not_zero() (Eric Dumazet)

   - Add kfunc for populating cpumask bits (Emil Tsalapatis)

   - Convert various shell based tests to selftests/bpf/test_progs
     format (Bastien Curutchet)

   - Allow passing referenced kptrs into struct_ops callbacks (Amery
     Hung)

   - Add a flag to LSM bpf hook to facilitate bpf program signing
     (Blaise Boscaccy)

   - Track arena arguments in kfuncs (Ihor Solodrai)

   - Add copy_remote_vm_str() helper for reading strings from remote VM
     and bpf_copy_from_user_task_str() kfunc (Jordan Rome)

   - Add support for timed may_goto instruction (Kumar Kartikeya
     Dwivedi)

   - Allow bpf_get_netns_cookie() int cgroup_skb programs (Mahe Tardy)

   - Reduce bpf_cgrp_storage_busy false positives when accessing cgroup
     local storage (Martin KaFai Lau)

   - Introduce bpf_dynptr_copy() kfunc (Mykyta Yatsenko)

   - Allow retrieving BTF data with BTF token (Mykyta Yatsenko)

   - Add BPF kfuncs to set and get xattrs with 'security.bpf.' prefix
     (Song Liu)

   - Reject attaching programs to noreturn functions (Yafang Shao)

   - Introduce pre-order traversal of cgroup bpf programs (Yonghong
     Song)"

* tag 'bpf-next-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (186 commits)
  selftests/bpf: Add selftests for load-acquire/store-release when register number is invalid
  bpf: Fix out-of-bounds read in check_atomic_load/store()
  libbpf: Add namespace for errstr making it libbpf_errstr
  bpf: Add struct_ops context information to struct bpf_prog_aux
  selftests/bpf: Sanitize pointer prior fclose()
  selftests/bpf: Migrate test_xdp_vlan.sh into test_progs
  selftests/bpf: test_xdp_vlan: Rename BPF sections
  bpf: clarify a misleading verifier error message
  selftests/bpf: Add selftest for attaching fexit to __noreturn functions
  bpf: Reject attaching fexit/fmod_ret to __noreturn functions
  bpf: Only fails the busy counter check in bpf_cgrp_storage_get if it creates storage
  bpf: Make perf_event_read_output accessible in all program types.
  bpftool: Using the right format specifiers
  bpftool: Add -Wformat-signedness flag to detect format errors
  selftests/bpf: Test freplace from user namespace
  libbpf: Pass BPF token from find_prog_btf_id to BPF_BTF_GET_FD_BY_ID
  bpf: Return prog btf_id without capable check
  bpf: BPF token support for BPF_BTF_GET_FD_BY_ID
  bpf, x86: Fix objtool warning for timed may_goto
  bpf: Check map-&gt;record at the beginning of check_and_free_fields()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull bpf updates from Alexei Starovoitov:
 "For this merge window we're splitting BPF pull request into three for
  higher visibility: main changes, res_spin_lock, try_alloc_pages.

  These are the main BPF changes:

   - Add DFA-based live registers analysis to improve verification of
     programs with loops (Eduard Zingerman)

   - Introduce load_acquire and store_release BPF instructions and add
     x86, arm64 JIT support (Peilin Ye)

   - Fix loop detection logic in the verifier (Eduard Zingerman)

   - Drop unnecesary lock in bpf_map_inc_not_zero() (Eric Dumazet)

   - Add kfunc for populating cpumask bits (Emil Tsalapatis)

   - Convert various shell based tests to selftests/bpf/test_progs
     format (Bastien Curutchet)

   - Allow passing referenced kptrs into struct_ops callbacks (Amery
     Hung)

   - Add a flag to LSM bpf hook to facilitate bpf program signing
     (Blaise Boscaccy)

   - Track arena arguments in kfuncs (Ihor Solodrai)

   - Add copy_remote_vm_str() helper for reading strings from remote VM
     and bpf_copy_from_user_task_str() kfunc (Jordan Rome)

   - Add support for timed may_goto instruction (Kumar Kartikeya
     Dwivedi)

   - Allow bpf_get_netns_cookie() int cgroup_skb programs (Mahe Tardy)

   - Reduce bpf_cgrp_storage_busy false positives when accessing cgroup
     local storage (Martin KaFai Lau)

   - Introduce bpf_dynptr_copy() kfunc (Mykyta Yatsenko)

   - Allow retrieving BTF data with BTF token (Mykyta Yatsenko)

   - Add BPF kfuncs to set and get xattrs with 'security.bpf.' prefix
     (Song Liu)

   - Reject attaching programs to noreturn functions (Yafang Shao)

   - Introduce pre-order traversal of cgroup bpf programs (Yonghong
     Song)"

* tag 'bpf-next-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (186 commits)
  selftests/bpf: Add selftests for load-acquire/store-release when register number is invalid
  bpf: Fix out-of-bounds read in check_atomic_load/store()
  libbpf: Add namespace for errstr making it libbpf_errstr
  bpf: Add struct_ops context information to struct bpf_prog_aux
  selftests/bpf: Sanitize pointer prior fclose()
  selftests/bpf: Migrate test_xdp_vlan.sh into test_progs
  selftests/bpf: test_xdp_vlan: Rename BPF sections
  bpf: clarify a misleading verifier error message
  selftests/bpf: Add selftest for attaching fexit to __noreturn functions
  bpf: Reject attaching fexit/fmod_ret to __noreturn functions
  bpf: Only fails the busy counter check in bpf_cgrp_storage_get if it creates storage
  bpf: Make perf_event_read_output accessible in all program types.
  bpftool: Using the right format specifiers
  bpftool: Add -Wformat-signedness flag to detect format errors
  selftests/bpf: Test freplace from user namespace
  libbpf: Pass BPF token from find_prog_btf_id to BPF_BTF_GET_FD_BY_ID
  bpf: Return prog btf_id without capable check
  bpf: BPF token support for BPF_BTF_GET_FD_BY_ID
  bpf, x86: Fix objtool warning for timed may_goto
  bpf: Check map-&gt;record at the beginning of check_and_free_fields()
  ...
</pre>
</div>
</content>
</entry>
</feed>
