[PATCH bpf-next v4 1/6] bpf: Add syscall common attrs support for link_create
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COOLING5d
SUPERSEDED
From: Leon Hwang <hidden>
Date: 2026-10-24 15:36:32
Also in:
bpf, linux-kselftest, lkml, netdev
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
Status: Superseded by v5 (posted 2026-10-26). [go to v5]
Revision v4 (5 revisions archived).
Revisions (5)
Similar to the syscall common attrs support for map_create [1], add the syscall common attrs support for link_create. Create and finalize the internal verifier log instance. Then, report the error messages for invalid prog fd, invalid attach type, and invalid prog type. Links: [1] https://lore.kernel.org/bpf/20260514004634.3DA09C19425@smtp.kernel.org/ (local) Link: https://lore.kernel.org/bpf/20260514004634.3DA09C19425@smtp.kernel.org/ (local) Signed-off-by: Leon Hwang <redacted> --- kernel/bpf/syscall.c | 35 ++++++++++++++++++++++++++++------- 1 file changed, 28 insertions(+), 7 deletions(-)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 90bc7230afa8..db870e795d04 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c@@ -5862,8 +5862,11 @@ static int bpf_map_do_batch(const union bpf_attr *attr, } #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.path_fd -static int link_create(union bpf_attr *attr, bpfptr_t uattr) +static int link_create(union bpf_attr *attr, bpfptr_t uattr, struct bpf_common_attr *attr_common, + bpfptr_t uattr_common, u32 size_common) { + struct bpf_verifier_log *log; + struct bpf_log_attr attr_log; struct bpf_prog *prog; int ret;
@@ -5873,14 +5876,24 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr) if (attr->link_create.attach_type == BPF_STRUCT_OPS) return bpf_struct_ops_link_create(attr); + log = bpf_log_attr_create_vlog(&attr_log, attr_common, uattr_common, size_common); + if (IS_ERR(log)) + return PTR_ERR(log); + prog = bpf_prog_get(attr->link_create.prog_fd); - if (IS_ERR(prog)) - return PTR_ERR(prog); + if (IS_ERR(prog)) { + bpf_log(log, "Invalid prog_fd.\n"); + ret = PTR_ERR(prog); + prog = NULL; + goto out; + } ret = bpf_prog_attach_check_attach_type(prog, attr->link_create.attach_type); - if (ret) + if (ret) { + bpf_log(log, "Invalid attach_type.\n"); goto out; + } switch (prog->type) { case BPF_PROG_TYPE_CGROUP_SKB:
@@ -5959,12 +5972,20 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr) ret = bpf_uprobe_multi_link_attach(attr, prog); break; default: + bpf_log(log, "Invalid prog type.\n"); ret = -EINVAL; } out: - if (ret < 0) - bpf_prog_put(prog); + if (ret < 0) { + int err; + + err = bpf_log_attr_finalize(&attr_log, log); + ret = err ? err : ret; + if (prog) + bpf_prog_put(prog); + } + kfree(log); return ret; }
@@ -6536,7 +6557,7 @@ static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size, err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH); break; case BPF_LINK_CREATE: - err = link_create(&attr, uattr); + err = link_create(&attr, uattr, &attr_common, uattr_common, size_common); break; case BPF_LINK_UPDATE: err = link_update(&attr);
--
2.55.0