Merge tag 'bpf-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Alexei Starovoitov:

 - Support pulling non-linear xdp data with bpf_xdp_pull_data() kfunc
   (Amery Hung)

   Applied as a stable branch in bpf-next and net-next trees.

 - Support reading skb metadata via bpf_dynptr (Jakub Sitnicki)

   Also a stable branch in bpf-next and net-next trees.

 - Enforce expected_attach_type for tailcall compatibility (Daniel
   Borkmann)

 - Replace path-sensitive with path-insensitive live stack analysis in
   the verifier (Eduard Zingerman)

   This is a significant change in the verification logic. More details,
   motivation, long term plans are in the cover letter/merge commit.

 - Support signed BPF programs (KP Singh)

   This is another major feature that took years to materialize.

   Algorithm details are in the cover letter/marge commit

 - Add support for may_goto instruction to s390 JIT (Ilya Leoshkevich)

 - Add support for may_goto instruction to arm64 JIT (Puranjay Mohan)

 - Fix USDT SIB argument handling in libbpf (Jiawei Zhao)

 - Allow uprobe-bpf program to change context registers (Jiri Olsa)

 - Support signed loads from BPF arena (Kumar Kartikeya Dwivedi and
   Puranjay Mohan)

 - Allow access to union arguments in tracing programs (Leon Hwang)

 - Optimize rcu_read_lock() + migrate_disable() combination where it's
   used in BPF subsystem (Menglong Dong)

 - Introduce bpf_task_work_schedule*() kfuncs to schedule deferred
   execution of BPF callback in the context of a specific task using the
   kernel’s task_work infrastructure (Mykyta Yatsenko)

 - Enforce RCU protection for KF_RCU_PROTECTED kfuncs (Kumar Kartikeya
   Dwivedi)

 - Add stress test for rqspinlock in NMI (Kumar Kartikeya Dwivedi)

 - Improve the precision of tnum multiplier verifier operation
   (Nandakumar Edamana)

 - Use tnums to improve is_branch_taken() logic (Paul Chaignon)

 - Add support for atomic operations in arena in riscv JIT (Pu Lehui)

 - Report arena faults to BPF error stream (Puranjay Mohan)

 - Search for tracefs at /sys/kernel/tracing first in bpftool (Quentin
   Monnet)

 - Add bpf_strcasecmp() kfunc (Rong Tao)

 - Support lookup_and_delete_elem command in BPF_MAP_STACK_TRACE (Tao
   Chen)

* tag 'bpf-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (197 commits)
  libbpf: Replace AF_ALG with open coded SHA-256
  selftests/bpf: Add stress test for rqspinlock in NMI
  selftests/bpf: Add test case for different expected_attach_type
  bpf: Enforce expected_attach_type for tailcall compatibility
  bpftool: Remove duplicate string.h header
  bpf: Remove duplicate crypto/sha2.h header
  libbpf: Fix error when st-prefix_ops and ops from differ btf
  selftests/bpf: Test changing packet data from kfunc
  selftests/bpf: Add stacktrace map lookup_and_delete_elem test case
  selftests/bpf: Refactor stacktrace_map case with skeleton
  bpf: Add lookup_and_delete_elem for BPF_MAP_STACK_TRACE
  selftests/bpf: Fix flaky bpf_cookie selftest
  selftests/bpf: Test changing packet data from global functions with a kfunc
  bpf: Emit struct bpf_xdp_sock type in vmlinux BTF
  selftests/bpf: Task_work selftest cleanup fixes
  MAINTAINERS: Delete inactive maintainers from AF_XDP
  bpf: Mark kfuncs as __noclone
  selftests/bpf: Add kprobe multi write ctx attach test
  selftests/bpf: Add kprobe write ctx attach test
  selftests/bpf: Add uprobe context ip register change test
  ...

Author: torvalds

CREDITS

@@ -3912,6 +3912,12 @@ S: C/ Federico Garcia Lorca 1 10-A
 S: Sevilla 41005
 S: Spain
 
+N: Björn Töpel
+E: bjorn@kernel.org
+D: AF_XDP
+S: Gothenburg
+S: Sweden
+
 N: Linus Torvalds
 E: torvalds@linux-foundation.org
 D: Original kernel hacker

Documentation/bpf/kfuncs.rst

@@ -335,9 +335,26 @@ consider doing refcnt != 0 check, especially when returning a KF_ACQUIRE
 pointer. Note as well that a KF_ACQUIRE kfunc that is KF_RCU should very likely
 also be KF_RET_NULL.
 
+2.4.8 KF_RCU_PROTECTED flag
+---------------------------
+
+The KF_RCU_PROTECTED flag is used to indicate that the kfunc must be invoked in
+an RCU critical section. This is assumed by default in non-sleepable programs,
+and must be explicitly ensured by calling ``bpf_rcu_read_lock`` for sleepable
+ones.
+
+If the kfunc returns a pointer value, this flag also enforces that the returned
+pointer is RCU protected, and can only be used while the RCU critical section is
+active.
+
+The flag is distinct from the ``KF_RCU`` flag, which only ensures that its
+arguments are at least RCU protected pointers. This may transitively imply that
+RCU protection is ensured, but it does not work in cases of kfuncs which require
+RCU protection but do not take RCU protected arguments.
+
 .. _KF_deprecated_flag:
 
-2.4.8 KF_DEPRECATED flag
+2.4.9 KF_DEPRECATED flag
 ------------------------
 
 The KF_DEPRECATED flag is used for kfuncs which are scheduled to be

Documentation/bpf/verifier.rst

@@ -347,270 +347,6 @@ However, only the value of register ``r1`` is important to successfully finish
 verification. The goal of the liveness tracking algorithm is to spot this fact
 and figure out that both states are actually equivalent.
 
-Data structures
-~~~~~~~~~~~~~~~
-
-Liveness is tracked using the following data structures::
-
-  enum bpf_reg_liveness {
-	REG_LIVE_NONE = 0,
-	REG_LIVE_READ32 = 0x1,
-	REG_LIVE_READ64 = 0x2,
-	REG_LIVE_READ = REG_LIVE_READ32 | REG_LIVE_READ64,
-	REG_LIVE_WRITTEN = 0x4,
-	REG_LIVE_DONE = 0x8,
-  };
-
-  struct bpf_reg_state {
- 	...
-	struct bpf_reg_state *parent;
- 	...
-	enum bpf_reg_liveness live;
- 	...
-  };
-
-  struct bpf_stack_state {
-	struct bpf_reg_state spilled_ptr;
-	...
-  };
-
-  struct bpf_func_state {
-	struct bpf_reg_state regs[MAX_BPF_REG];
-        ...
-	struct bpf_stack_state *stack;
-  }
-
-  struct bpf_verifier_state {
-	struct bpf_func_state *frame[MAX_CALL_FRAMES];
-	struct bpf_verifier_state *parent;
-        ...
-  }
-
-* ``REG_LIVE_NONE`` is an initial value assigned to ``->live`` fields upon new
-  verifier state creation;
-
-* ``REG_LIVE_WRITTEN`` means that the value of the register (or stack slot) is
-  defined by some instruction verified between this verifier state's parent and
-  verifier state itself;
-
-* ``REG_LIVE_READ{32,64}`` means that the value of the register (or stack slot)
-  is read by a some child state of this verifier state;
-
-* ``REG_LIVE_DONE`` is a marker used by ``clean_verifier_state()`` to avoid
-  processing same verifier state multiple times and for some sanity checks;
-
-* ``->live`` field values are formed by combining ``enum bpf_reg_liveness``
-  values using bitwise or.
-
-Register parentage chains
-~~~~~~~~~~~~~~~~~~~~~~~~~
-
-In order to propagate information between parent and child states, a *register
-parentage chain* is established. Each register or stack slot is linked to a
-corresponding register or stack slot in its parent state via a ``->parent``
-pointer. This link is established upon state creation in ``is_state_visited()``
-and might be modified by ``set_callee_state()`` called from
-``__check_func_call()``.
-
-The rules for correspondence between registers / stack slots are as follows:
-
-* For the current stack frame, registers and stack slots of the new state are
-  linked to the registers and stack slots of the parent state with the same
-  indices.
-
-* For the outer stack frames, only callee saved registers (r6-r9) and stack
-  slots are linked to the registers and stack slots of the parent state with the
-  same indices.
-
-* When function call is processed a new ``struct bpf_func_state`` instance is
-  allocated, it encapsulates a new set of registers and stack slots. For this
-  new frame, parent links for r6-r9 and stack slots are set to nil, parent links
-  for r1-r5 are set to match caller r1-r5 parent links.
-
-This could be illustrated by the following diagram (arrows stand for
-``->parent`` pointers)::
-
-      ...                    ; Frame #0, some instructions
-  --- checkpoint #0 ---
-  1 : r6 = 42                ; Frame #0
-  --- checkpoint #1 ---
-  2 : call foo()             ; Frame #0
-      ...                    ; Frame #1, instructions from foo()
-  --- checkpoint #2 ---
-      ...                    ; Frame #1, instructions from foo()
-  --- checkpoint #3 ---
-      exit                   ; Frame #1, return from foo()
-  3 : r1 = r6                ; Frame #0  <- current state
-
-             +-------------------------------+-------------------------------+
-             |           Frame #0            |           Frame #1            |
-  Checkpoint +-------------------------------+-------------------------------+
-  #0         | r0 | r1-r5 | r6-r9 | fp-8 ... |
-             +-------------------------------+
-                ^    ^       ^       ^
-                |    |       |       |
-  Checkpoint +-------------------------------+
-  #1         | r0 | r1-r5 | r6-r9 | fp-8 ... |
-             +-------------------------------+
-                     ^       ^       ^
-                     |_______|_______|_______________
-                             |       |               |
-               nil  nil      |       |               |      nil     nil
-                |    |       |       |               |       |       |
-  Checkpoint +-------------------------------+-------------------------------+
-  #2         | r0 | r1-r5 | r6-r9 | fp-8 ... | r0 | r1-r5 | r6-r9 | fp-8 ... |
-             +-------------------------------+-------------------------------+
-                             ^       ^               ^       ^       ^
-               nil  nil      |       |               |       |       |
-                |    |       |       |               |       |       |
-  Checkpoint +-------------------------------+-------------------------------+
-  #3         | r0 | r1-r5 | r6-r9 | fp-8 ... | r0 | r1-r5 | r6-r9 | fp-8 ... |
-             +-------------------------------+-------------------------------+
-                             ^       ^
-               nil  nil      |       |
-                |    |       |       |
-  Current    +-------------------------------+
-  state      | r0 | r1-r5 | r6-r9 | fp-8 ... |
-             +-------------------------------+
-                             \
-                               r6 read mark is propagated via these links
-                               all the way up to checkpoint #1.
-                               The checkpoint #1 contains a write mark for r6
-                               because of instruction (1), thus read propagation
-                               does not reach checkpoint #0 (see section below).
-
-Liveness marks tracking
-~~~~~~~~~~~~~~~~~~~~~~~
-
-For each processed instruction, the verifier tracks read and written registers
-and stack slots. The main idea of the algorithm is that read marks propagate
-back along the state parentage chain until they hit a write mark, which 'screens
-off' earlier states from the read. The information about reads is propagated by
-function ``mark_reg_read()`` which could be summarized as follows::
-
-  mark_reg_read(struct bpf_reg_state *state, ...):
-      parent = state->parent
-      while parent:
-          if state->live & REG_LIVE_WRITTEN:
-              break
-          if parent->live & REG_LIVE_READ64:
-              break
-          parent->live |= REG_LIVE_READ64
-          state = parent
-          parent = state->parent
-
-Notes:
-
-* The read marks are applied to the **parent** state while write marks are
-  applied to the **current** state. The write mark on a register or stack slot
-  means that it is updated by some instruction in the straight-line code leading
-  from the parent state to the current state.
-
-* Details about REG_LIVE_READ32 are omitted.
-
-* Function ``propagate_liveness()`` (see section :ref:`read_marks_for_cache_hits`)
-  might override the first parent link. Please refer to the comments in the
-  ``propagate_liveness()`` and ``mark_reg_read()`` source code for further
-  details.
-
-Because stack writes could have different sizes ``REG_LIVE_WRITTEN`` marks are
-applied conservatively: stack slots are marked as written only if write size
-corresponds to the size of the register, e.g. see function ``save_register_state()``.
-
-Consider the following example::
-
-  0: (*u64)(r10 - 8) = 0   ; define 8 bytes of fp-8
-  --- checkpoint #0 ---
-  1: (*u32)(r10 - 8) = 1   ; redefine lower 4 bytes
-  2: r1 = (*u32)(r10 - 8)  ; read lower 4 bytes defined at (1)
-  3: r2 = (*u32)(r10 - 4)  ; read upper 4 bytes defined at (0)
-
-As stated above, the write at (1) does not count as ``REG_LIVE_WRITTEN``. Should
-it be otherwise, the algorithm above wouldn't be able to propagate the read mark
-from (3) to checkpoint #0.
-
-Once the ``BPF_EXIT`` instruction is reached ``update_branch_counts()`` is
-called to update the ``->branches`` counter for each verifier state in a chain
-of parent verifier states. When the ``->branches`` counter reaches zero the
-verifier state becomes a valid entry in a set of cached verifier states.
-
-Each entry of the verifier states cache is post-processed by a function
-``clean_live_states()``. This function marks all registers and stack slots
-without ``REG_LIVE_READ{32,64}`` marks as ``NOT_INIT`` or ``STACK_INVALID``.
-Registers/stack slots marked in this way are ignored in function ``stacksafe()``
-called from ``states_equal()`` when a state cache entry is considered for
-equivalence with a current state.
-
-Now it is possible to explain how the example from the beginning of the section
-works::
-
-  0: call bpf_get_prandom_u32()
-  1: r1 = 0
-  2: if r0 == 0 goto +1
-  3: r0 = 1
-  --- checkpoint[0] ---
-  4: r0 = r1
-  5: exit
-
-* At instruction #2 branching point is reached and state ``{ r0 == 0, r1 == 0, pc == 4 }``
-  is pushed to states processing queue (pc stands for program counter).
-
-* At instruction #4:
-
-  * ``checkpoint[0]`` states cache entry is created: ``{ r0 == 1, r1 == 0, pc == 4 }``;
-  * ``checkpoint[0].r0`` is marked as written;
-  * ``checkpoint[0].r1`` is marked as read;
-
-* At instruction #5 exit is reached and ``checkpoint[0]`` can now be processed
-  by ``clean_live_states()``. After this processing ``checkpoint[0].r1`` has a
-  read mark and all other registers and stack slots are marked as ``NOT_INIT``
-  or ``STACK_INVALID``
-
-* The state ``{ r0 == 0, r1 == 0, pc == 4 }`` is popped from the states queue
-  and is compared against a cached state ``{ r1 == 0, pc == 4 }``, the states
-  are considered equivalent.
-
-.. _read_marks_for_cache_hits:
-
-Read marks propagation for cache hits
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-Another point is the handling of read marks when a previously verified state is
-found in the states cache. Upon cache hit verifier must behave in the same way
-as if the current state was verified to the program exit. This means that all
-read marks, present on registers and stack slots of the cached state, must be
-propagated over the parentage chain of the current state. Example below shows
-why this is important. Function ``propagate_liveness()`` handles this case.
-
-Consider the following state parentage chain (S is a starting state, A-E are
-derived states, -> arrows show which state is derived from which)::
-
-                   r1 read
-            <-------------                A[r1] == 0
-                                          C[r1] == 0
-      S ---> A ---> B ---> exit           E[r1] == 1
-      |
-      ` ---> C ---> D
-      |
-      ` ---> E      ^
-                    |___   suppose all these
-             ^           states are at insn #Y
-             |
-      suppose all these
-    states are at insn #X
-
-* Chain of states ``S -> A -> B -> exit`` is verified first.
-
-* While ``B -> exit`` is verified, register ``r1`` is read and this read mark is
-  propagated up to state ``A``.
-
-* When chain of states ``C -> D`` is verified the state ``D`` turns out to be
-  equivalent to state ``B``.
-
-* The read mark for ``r1`` has to be propagated to state ``C``, otherwise state
-  ``C`` might get mistakenly marked as equivalent to state ``E`` even though
-  values for register ``r1`` differ between ``C`` and ``E``.
-
 Understanding eBPF verifier messages
 ====================================
 

MAINTAINERS

@@ -27466,10 +27466,8 @@ F:	tools/testing/selftests/bpf/*xdp*
 K:	(?:\b|_)xdp(?:\b|_)
 
 XDP SOCKETS (AF_XDP)
-M:	Björn Töpel <bjorn@kernel.org>
 M:	Magnus Karlsson <magnus.karlsson@intel.com>
 M:	Maciej Fijalkowski <maciej.fijalkowski@intel.com>
-R:	Jonathan Lemon <jonathan.lemon@gmail.com>
 R:	Stanislav Fomichev <sdf@fomichev.me>
 L:	netdev@vger.kernel.org
 L:	bpf@vger.kernel.org

arch/arm64/net/Makefile

@@ -2,4 +2,4 @@
 #
 # ARM64 networking code
 #
-obj-$(CONFIG_BPF_JIT) += bpf_jit_comp.o
+obj-$(CONFIG_BPF_JIT) += bpf_jit_comp.o bpf_timed_may_goto.o