Merge tag 'bpf-next-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Alexei Starovoitov:

 - Introduce '__attribute__((bpf_fastcall))' for helpers and kfuncs with
   corresponding support in LLVM.

   It is similar to existing 'no_caller_saved_registers' attribute in
   GCC/LLVM with a provision for backward compatibility. It allows
   compilers generate more efficient BPF code assuming the verifier or
   JITs will inline or partially inline a helper/kfunc with such
   attribute. bpf_cast_to_kern_ctx, bpf_rdonly_cast,
   bpf_get_smp_processor_id are the first set of such helpers.

 - Harden and extend ELF build ID parsing logic.

   When called from sleepable context the relevants parts of ELF file
   will be read to find and fetch .note.gnu.build-id information. Also
   harden the logic to avoid TOCTOU, overflow, out-of-bounds problems.

 - Improvements and fixes for sched-ext:
    - Allow passing BPF iterators as kfunc arguments
    - Make the pointer returned from iter_next method trusted
    - Fix x86 JIT convergence issue due to growing/shrinking conditional
      jumps in variable length encoding

 - BPF_LSM related:
    - Introduce few VFS kfuncs and consolidate them in
      fs/bpf_fs_kfuncs.c
    - Enforce correct range of return values from certain LSM hooks
    - Disallow attaching to other LSM hooks

 - Prerequisite work for upcoming Qdisc in BPF:
    - Allow kptrs in program provided structs
    - Support for gen_epilogue in verifier_ops

 - Important fixes:
    - Fix uprobe multi pid filter check
    - Fix bpf_strtol and bpf_strtoul helpers
    - Track equal scalars history on per-instruction level
    - Fix tailcall hierarchy on x86 and arm64
    - Fix signed division overflow to prevent INT_MIN/-1 trap on x86
    - Fix get kernel stack in BPF progs attached to tracepoint:syscall

 - Selftests:
    - Add uprobe bench/stress tool
    - Generate file dependencies to drastically improve re-build time
    - Match JIT-ed and BPF asm with __xlated/__jited keywords
    - Convert older tests to test_progs framework
    - Add support for RISC-V
    - Few fixes when BPF programs are compiled with GCC-BPF backend
      (support for GCC-BPF in BPF CI is ongoing in parallel)
    - Add traffic monitor
    - Enable cross compile and musl libc

* tag 'bpf-next-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (260 commits)
  btf: require pahole 1.21+ for DEBUG_INFO_BTF with default DWARF version
  btf: move pahole check in scripts/link-vmlinux.sh to lib/Kconfig.debug
  btf: remove redundant CONFIG_BPF test in scripts/link-vmlinux.sh
  bpf: Call the missed kfree() when there is no special field in btf
  bpf: Call the missed btf_record_free() when map creation fails
  selftests/bpf: Add a test case to write mtu result into .rodata
  selftests/bpf: Add a test case to write strtol result into .rodata
  selftests/bpf: Rename ARG_PTR_TO_LONG test description
  selftests/bpf: Fix ARG_PTR_TO_LONG {half-,}uninitialized test
  bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error
  bpf: Improve check_raw_mode_ok test for MEM_UNINIT-tagged types
  bpf: Fix helper writes to read-only maps
  bpf: Remove truncation test in bpf_strtol and bpf_strtoul helpers
  bpf: Fix bpf_strtol and bpf_strtoul helpers for 32bit
  selftests/bpf: Add tests for sdiv/smod overflow cases
  bpf: Fix a sdiv overflow issue
  libbpf: Add bpf_object__token_fd accessor
  docs/bpf: Add missing BPF program types to docs
  docs/bpf: Add constant values for linkages
  bpf: Use fake pt_regs when doing bpf syscall tracepoint tracing
  ...

3 files changed, 62 insertions, 9 deletions

diff --git a/Documentation/bpf/btf.rst b/Documentation/bpf/btf.rst
index 257a7e1cdf5d..93060283b6fd 100644
--- a/Documentation/bpf/btf.rst
+++ b/Documentation/bpf/btf.rst
@@ -368,7 +368,7 @@ No additional type data follow ``btf_type``.
   * ``info.kind_flag``: 0
   * ``info.kind``: BTF_KIND_FUNC
   * ``info.vlen``: linkage information (BTF_FUNC_STATIC, BTF_FUNC_GLOBAL
-                   or BTF_FUNC_EXTERN)
+                   or BTF_FUNC_EXTERN - see :ref:`BTF_Function_Linkage_Constants`)
   * ``type``: a BTF_KIND_FUNC_PROTO type
 
 No additional type data follow ``btf_type``.
@@ -424,9 +424,8 @@ following data::
         __u32   linkage;
     };
 
-``struct btf_var`` encoding:
-  * ``linkage``: currently only static variable 0, or globally allocated
-                 variable in ELF sections 1
+``btf_var.linkage`` may take the values: BTF_VAR_STATIC, BTF_VAR_GLOBAL_ALLOCATED or BTF_VAR_GLOBAL_EXTERN -
+see :ref:`BTF_Var_Linkage_Constants`.
 
 Not all type of global variables are supported by LLVM at this point.
 The following is currently available:
@@ -549,6 +548,38 @@ The ``btf_enum64`` encoding:
 If the original enum value is signed and the size is less than 8,
 that value will be sign extended into 8 bytes.
 
+2.3 Constant Values
+-------------------
+
+.. _BTF_Function_Linkage_Constants:
+
+2.3.1 Function Linkage Constant Values
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+.. table:: Function Linkage Values and Meanings
+
+  ===================  =====  ===========
+  kind                 value  description
+  ===================  =====  ===========
+  ``BTF_FUNC_STATIC``  0x0    definition of subprogram not visible outside containing compilation unit
+  ``BTF_FUNC_GLOBAL``  0x1    definition of subprogram visible outside containing compilation unit
+  ``BTF_FUNC_EXTERN``  0x2    declaration of a subprogram whose definition is outside the containing compilation unit
+  ===================  =====  ===========
+
+
+.. _BTF_Var_Linkage_Constants:
+
+2.3.2 Variable Linkage Constant Values
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+.. table:: Variable Linkage Values and Meanings
+
+  ============================  =====  ===========
+  kind                          value  description
+  ============================  =====  ===========
+  ``BTF_VAR_STATIC``            0x0    definition of global variable not visible outside containing compilation unit
+  ``BTF_VAR_GLOBAL_ALLOCATED``  0x1    definition of global variable visible outside containing compilation unit
+  ``BTF_VAR_GLOBAL_EXTERN``     0x2    declaration of global variable whose definition is outside the containing compilation unit
+  ============================  =====  ===========
+
 3. BTF Kernel API
 =================
 
diff --git a/Documentation/bpf/libbpf/program_types.rst b/Documentation/bpf/libbpf/program_types.rst
index 63bb88846e50..218b020a2f81 100644
--- a/Documentation/bpf/libbpf/program_types.rst
+++ b/Documentation/bpf/libbpf/program_types.rst
@@ -121,6 +121,8 @@ described in more detail in the footnotes.
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
 | ``BPF_PROG_TYPE_LWT_XMIT``                |                                        | ``lwt_xmit``                     |           |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
+| ``BPF_PROG_TYPE_NETFILTER``               |                                        | ``netfilter``                    |           |
++-------------------------------------------+----------------------------------------+----------------------------------+-----------+
 | ``BPF_PROG_TYPE_PERF_EVENT``              |                                        | ``perf_event``                   |           |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
 | ``BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE`` |                                        | ``raw_tp.w+`` [#rawtp]_          |           |
@@ -131,11 +133,23 @@ described in more detail in the footnotes.
 +                                           +                                        +----------------------------------+-----------+
 |                                           |                                        | ``raw_tracepoint+``              |           |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
-| ``BPF_PROG_TYPE_SCHED_ACT``               |                                        | ``action``                       |           |
+| ``BPF_PROG_TYPE_SCHED_ACT``               |                                        | ``action`` [#tc_legacy]_         |           |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
-| ``BPF_PROG_TYPE_SCHED_CLS``               |                                        | ``classifier``                   |           |
+| ``BPF_PROG_TYPE_SCHED_CLS``               |                                        | ``classifier`` [#tc_legacy]_     |           |
 +                                           +                                        +----------------------------------+-----------+
-|                                           |                                        | ``tc``                           |           |
+|                                           |                                        | ``tc`` [#tc_legacy]_             |           |
++                                           +----------------------------------------+----------------------------------+-----------+
+|                                           | ``BPF_NETKIT_PRIMARY``                 | ``netkit/primary``               |           |
++                                           +----------------------------------------+----------------------------------+-----------+
+|                                           | ``BPF_NETKIT_PEER``                    | ``netkit/peer``                  |           |
++                                           +----------------------------------------+----------------------------------+-----------+
+|                                           | ``BPF_TCX_INGRESS``                    | ``tc/ingress``                   |           |
++                                           +----------------------------------------+----------------------------------+-----------+
+|                                           | ``BPF_TCX_EGRESS``                     | ``tc/egress``                    |           |
++                                           +----------------------------------------+----------------------------------+-----------+
+|                                           | ``BPF_TCX_INGRESS``                    | ``tcx/ingress``                  |           |
++                                           +----------------------------------------+----------------------------------+-----------+
+|                                           | ``BPF_TCX_EGRESS``                     | ``tcx/egress``                   |           |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
 | ``BPF_PROG_TYPE_SK_LOOKUP``               | ``BPF_SK_LOOKUP``                      | ``sk_lookup``                    |           |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
@@ -155,7 +169,9 @@ described in more detail in the footnotes.
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
 | ``BPF_PROG_TYPE_SOCK_OPS``                | ``BPF_CGROUP_SOCK_OPS``                | ``sockops``                      |           |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
-| ``BPF_PROG_TYPE_STRUCT_OPS``              |                                        | ``struct_ops+``                  |           |
+| ``BPF_PROG_TYPE_STRUCT_OPS``              |                                        | ``struct_ops+`` [#struct_ops]_   |           |
++                                           +                                        +----------------------------------+-----------+
+|                                           |                                        | ``struct_ops.s+`` [#struct_ops]_ | Yes       |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
 | ``BPF_PROG_TYPE_SYSCALL``                 |                                        | ``syscall``                      | Yes       |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
@@ -209,5 +225,11 @@ described in more detail in the footnotes.
               ``a-zA-Z0-9_.*?``.
 .. [#lsm] The ``lsm`` attachment format is ``lsm[.s]/<hook>``.
 .. [#rawtp] The ``raw_tp`` attach format is ``raw_tracepoint[.w]/<tracepoint>``.
+.. [#tc_legacy] The ``tc``, ``classifier`` and ``action`` attach types are deprecated, use
+                ``tcx/*`` instead.
+.. [#struct_ops] The ``struct_ops`` attach format supports ``struct_ops[.s]/<name>`` convention,
+                 but ``name`` is ignored and it is recommended to just use plain
+                 ``SEC("struct_ops[.s]")``. The attachments are defined in a struct initializer
+                 that is tagged with ``SEC(".struct_ops[.link]")``.
 .. [#tp] The ``tracepoint`` attach format is ``tracepoint/<category>/<name>``.
 .. [#iter] The ``iter`` attach format is ``iter[.s]/<struct-name>``.
diff --git a/Documentation/bpf/verifier.rst b/Documentation/bpf/verifier.rst
index 356894399fbf..d23761540002 100644
--- a/Documentation/bpf/verifier.rst
+++ b/Documentation/bpf/verifier.rst
@@ -418,7 +418,7 @@ The rules for correspondence between registers / stack slots are as follows:
   linked to the registers and stack slots of the parent state with the same
   indices.
 
-* For the outer stack frames, only caller saved registers (r6-r9) and stack
+* 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.