linux/kernel/bpf/btf.c, branch v6.17

Merge tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2025-07-30T16:58:50Z

Pull bpf updates from Alexei Starovoitov: - Remove usermode driver (UMD) framework (Thomas Weißschuh) - Introduce Strongly Connected Component (SCC) in the verifier to detect loops and refine register liveness (Eduard Zingerman) - Allow 'void *' cast using bpf_rdonly_cast() and corresponding '__arg_untrusted' for global function parameters (Eduard Zingerman) - Improve precision for BPF_ADD and BPF_SUB operations in the verifier (Harishankar Vishwanathan) - Teach the verifier that constant pointer to a map cannot be NULL (Ihor Solodrai) - Introduce BPF streams for error reporting of various conditions detected by BPF runtime (Kumar Kartikeya Dwivedi) - Teach the verifier to insert runtime speculation barrier (lfence on x86) to mitigate speculative execution instead of rejecting the programs (Luis Gerhorst) - Various improvements for 'veristat' (Mykyta Yatsenko) - For CONFIG_DEBUG_KERNEL config warn on internal verifier errors to improve bug detection by syzbot (Paul Chaignon) - Support BPF private stack on arm64 (Puranjay Mohan) - Introduce bpf_cgroup_read_xattr() kfunc to read xattr of cgroup's node (Song Liu) - Introduce kfuncs for read-only string opreations (Viktor Malik) - Implement show_fdinfo() for bpf_links (Tao Chen) - Reduce verifier's stack consumption (Yonghong Song) - Implement mprog API for cgroup-bpf programs (Yonghong Song) * tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (192 commits) selftests/bpf: Migrate fexit_noreturns case into tracing_failure test suite selftests/bpf: Add selftest for attaching tracing programs to functions in deny list bpf: Add log for attaching tracing programs to functions in deny list bpf: Show precise rejected function when attaching fexit/fmod_ret to __noreturn functions bpf: Fix various typos in verifier.c comments bpf: Add third round of bounds deduction selftests/bpf: Test invariants on JSLT crossing sign selftests/bpf: Test cross-sign 64bits range refinement selftests/bpf: Update reg_bound range refinement logic bpf: Improve bounds when s64 crosses sign boundary bpf: Simplify bounds refinement from s32 selftests/bpf: Enable private stack tests for arm64 bpf, arm64: JIT support for private stack bpf: Move bpf_jit_get_prog_name() to core.c bpf, arm64: Fix fp initialization for exception boundary umd: Remove usermode driver framework bpf/preload: Don't select USERMODE_DRIVER selftests/bpf: Fix test dynptr/test_dynptr_memset_xdp_chunks failure selftests/bpf: Fix test dynptr/test_dynptr_copy_xdp failure selftests/bpf: Increase xdp data size for arm64 64K page size ...

bpf: Clean up individual BTF_ID code

2025-07-17T01:34:42Z

Use BTF_ID_LIST_SINGLE(a, b, c) instead of BTF_ID_LIST(a) BTF_ID(b, c) Signed-off-by: Feng Yang Link: https://lore.kernel.org/r/20250710055419.70544-1-yangfeng59949@163.com Signed-off-by: Alexei Starovoitov

bpf: support for void/primitive __arg_untrusted global func params

2025-07-07T15:25:07Z

Allow specifying __arg_untrusted for void */char */int */long * parameters. Treat such parameters as PTR_TO_MEM|MEM_RDONLY|PTR_UNTRUSTED of size zero. Intended usage is as follows: int memcmp(char *a __arg_untrusted, char *b __arg_untrusted, size_t n) { bpf_for(i, 0, n) { if (a[i] - b[i]) // load at any offset is allowed return a[i] - b[i]; } return 0; } Allocate register id for ARG_PTR_TO_MEM parameters only when PTR_MAYBE_NULL is set. Register id for PTR_TO_MEM is used only to propagate non-null status after conditionals. Suggested-by: Alexei Starovoitov Acked-by: Kumar Kartikeya Dwivedi Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/r/20250704230354.1323244-8-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov

bpf: attribute __arg_untrusted for global function parameters

2025-07-07T15:25:06Z

Add support for PTR_TO_BTF_ID | PTR_UNTRUSTED global function parameters. Anything is allowed to pass to such parameters, as these are read-only and probe read instructions would protect against invalid memory access. Suggested-by: Alexei Starovoitov Acked-by: Kumar Kartikeya Dwivedi Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/r/20250704230354.1323244-5-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov

bpf: rdonly_untrusted_mem for btf id walk pointer leafs

2025-07-07T15:25:06Z

When processing a load from a PTR_TO_BTF_ID, the verifier calculates the type of the loaded structure field based on the load offset. For example, given the following types: struct foo { struct foo *a; int *b; } *p; The verifier would calculate the type of `p->a` as a pointer to `struct foo`. However, the type of `p->b` is currently calculated as a SCALAR_VALUE. This commit updates the logic for processing PTR_TO_BTF_ID to instead calculate the type of p->b as PTR_TO_MEM|MEM_RDONLY|PTR_UNTRUSTED. This change allows further dereferencing of such pointers (using probe memory instructions). Suggested-by: Alexei Starovoitov Acked-by: Kumar Kartikeya Dwivedi Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/r/20250704230354.1323244-3-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov

bpf: add btf_type_is_i{32,64} helpers

2025-06-25T22:15:49Z

There are places in BPF code which check if a BTF type is an integer of particular size. This code can be made simpler by using helpers. Add new btf_type_is_i{32,64} helpers, and simplify code in a few files. (Suggested by Eduard for a patch which copy-pasted such a check [1].) v1 -> v2: * export less generic helpers (Eduard) * make subject less generic than in [v1] (Eduard) [1] https://lore.kernel.org/bpf/7edb47e73baa46705119a23c6bf4af26517a640f.camel@gmail.com/ [v1] https://lore.kernel.org/bpf/20250624193655.733050-1-a.s.protopopov@gmail.com/ Suggested-by: Eduard Zingerman Signed-off-by: Anton Protopopov Acked-by: Eduard Zingerman Link: https://lore.kernel.org/r/20250625151621.1000584-1-a.s.protopopov@gmail.com Signed-off-by: Alexei Starovoitov

sysfs: treewide: switch back to bin_attribute::read()/write()

2025-06-17T08:44:13Z

The bin_attribute argument of bin_attribute::read() is now const. This makes the _new() callbacks unnecessary. Switch all users back. Signed-off-by: Thomas Weißschuh Link: https://lore.kernel.org/r/20250530-sysfs-const-bin_attr-final-v3-3-724bfcf05b99@weissschuh.net Signed-off-by: Greg Kroah-Hartman

bpf: Include verifier memory allocations in memcg statistics

2025-06-13T17:29:45Z

This commit adds __GFP_ACCOUNT flag to verifier induced memory allocations. The intent is to account for all allocations reachable from BPF_PROG_LOAD command, which is needed to track verifier memory consumption in veristat. This includes allocations done in verifier.c, and some allocations in btf.c, functions in log.c do not allocate. There is also a utility function bpf_memcg_flags() which selectively adds GFP_ACCOUNT flag depending on the `cgroup.memory=nobpf` option. As far as I understand [1], the idea is to remove bpf_prog instances and maps from memcg accounting as these objects do not strictly belong to cgroup, hence it should not apply here. (btf_parse_fields() is reachable from both program load and map creation, but allocated record is not persistent as is freed as soon as map_check_btf() exits). [1] https://lore.kernel.org/all/20230210154734.4416-1-laoar.shao@gmail.com/ Signed-off-by: Eduard Zingerman Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250613072147.3938139-2-eddyz87@gmail.com

Merge tag 'bpf-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2025-05-28T22:52:42Z

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 ...

bpf: WARN_ONCE on verifier bugs

2025-05-19T15:17:08Z

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 Signed-off-by: Paul Chaignon Link: https://lore.kernel.org/r/aCs1nYvNNMq8dAWP@mail.gmail.com Signed-off-by: Alexei Starovoitov