test: guard ai agent exec override size

Author: kylewanginchina

agent/src/ebpf/test/test_ai_agent_source_contracts.py

@@ -229,6 +229,7 @@ def read_source(path: Path) -> str:
 if ENTERPRISE_AGENT.exists():
     exec_enforce_bpf = ENTERPRISE_BPF / "ai_agent_exec_enforce.bpf.c"
     exec_common_bpf = ENTERPRISE_BPF / "ai_agent_exec_common.bpf.h"
+    enforcement_common_bpf = ENTERPRISE_BPF / "ai_agent_enforcement_common.bpf.h"
     require(
         exec_enforce_bpf.exists(),
         f"missing enterprise AI Agent exec enforcement BPF: {exec_enforce_bpf}",
@@ -237,8 +238,13 @@ def read_source(path: Path) -> str:
         exec_common_bpf.exists(),
         f"missing enterprise AI Agent exec common BPF header: {exec_common_bpf}",
     )
+    require(
+        enforcement_common_bpf.exists(),
+        f"missing enterprise AI Agent enforcement common BPF header: {enforcement_common_bpf}",
+    )
     exec_enforce_text = read_source(exec_enforce_bpf)
     exec_common_text = read_source(exec_common_bpf)
+    enforcement_common_text = read_source(enforcement_common_bpf)
     support_text = read_source(ENTERPRISE_SUPPORT)
     feature_top_text = read_source(ENTERPRISE_FEATURE_TOP)
 
@@ -287,6 +293,16 @@ def read_source(path: Path) -> str:
         and "ai_agent_exec_collect_path_facts" in exec_common_text,
         "AI Agent exec enforcement BPF must support suffix path matching with precomputed hashes",
     )
+    path_facts_start = exec_common_text.find("ai_agent_exec_collect_path_facts(")
+    path_facts_end = exec_common_text.find("ai_agent_hash_exec_path", path_facts_start)
+    require(
+        path_facts_start != -1 and path_facts_end != -1,
+        "AI Agent exec BPF must keep path fact helper recognizable",
+    )
+    require(
+        "#pragma unroll" not in exec_common_text[path_facts_start:path_facts_end],
+        "AI Agent exec path fact collection must use a bounded loop, not a 256-byte unroll that bloats verifier processing",
+    )
     require(
         "AI_AGENT_EXEC_CMDLINE_PREFIX_LEN" in exec_common_text
         and "cmdline_prefix_len" in exec_common_text
@@ -325,6 +341,11 @@ def read_source(path: Path) -> str:
         "ai_agent_submit_event" in exec_common_text,
         "AI Agent exec enforcement must submit events through the AI Agent pipeline",
     )
+    require(
+        "__builtin_memset(event, 0, sizeof(*event))" not in enforcement_common_text
+        and "__builtin_memset(dst, 0, dst_sz)" not in enforcement_common_text,
+        "AI Agent enforcement event helpers must avoid large BPF memset expansions that push kprobe override programs over the 4096-insn limit",
+    )
     require(
         "cmdline_src_sz" in exec_common_text
         and "cmdline, cmdline_src_sz" in exec_common_text
@@ -401,6 +422,57 @@ def read_source(path: Path) -> str:
         and "cmdline_prefix_masks" in exec_override_text,
         "AI Agent exec override must match cmdline prefixes by fixed word masks",
     )
+    cmdline_prefix_match_start = exec_override_text.find(
+        "ai_agent_exec_override_cmdline_prefix_matches("
+    )
+    cmdline_prefix_match_end = exec_override_text.find(
+        "ai_agent_exec_override_path_matches", cmdline_prefix_match_start
+    )
+    require(
+        cmdline_prefix_match_start != -1 and cmdline_prefix_match_end != -1,
+        "AI Agent exec override must keep cmdline prefix match helper recognizable",
+    )
+    cmdline_prefix_match_text = exec_override_text[
+        cmdline_prefix_match_start:cmdline_prefix_match_end
+    ]
+    require(
+        "#pragma unroll" not in cmdline_prefix_match_text,
+        "AI Agent exec override must not unroll 32-word cmdline prefix matching; it makes verifier state exceed the 1M processed-insn limit",
+    )
+    append_arg_start = exec_override_text.find(
+        "ai_agent_exec_override_cmdline_append_arg("
+    )
+    read_argv_ptr_start = exec_override_text.find(
+        "ai_agent_exec_override_read_argv_ptr", append_arg_start
+    )
+    build_cmdline_start = exec_override_text.find(
+        "ai_agent_exec_override_build_cmdline("
+    )
+    read_argv_index_start = exec_override_text.find(
+        "ai_agent_exec_override_read_argv_index", build_cmdline_start
+    )
+    require(
+        append_arg_start != -1
+        and read_argv_ptr_start != -1
+        and build_cmdline_start != -1
+        and read_argv_index_start != -1,
+        "AI Agent exec override must keep cmdline build helpers recognizable",
+    )
+    cmdline_append_arg_text = exec_override_text[append_arg_start:read_argv_ptr_start]
+    build_cmdline_text = exec_override_text[build_cmdline_start:read_argv_index_start]
+    require(
+        "#pragma unroll" not in cmdline_append_arg_text
+        and "#pragma unroll" not in build_cmdline_text,
+        "AI Agent exec override must not unroll argv cmdline construction; it makes kprobe override programs too large",
+    )
+    require(
+        "ai_agent_exec_override_arg_reset" in exec_override_text
+        and "__builtin_memset(buf, 0, sizeof(*buf))" not in exec_override_text
+        and "__builtin_memset(buf->arg.bytes" not in exec_override_text
+        and "__builtin_memset(buf->cmdline.bytes" not in exec_override_text
+        and "__builtin_memset(buf->cmdline_arg.bytes" not in exec_override_text,
+        "AI Agent exec override must avoid large scratch-buffer memset expansions; reset only fields that need deterministic contents",
+    )
     require(
         "cmdline.bytes[buf->cmdline_len]" not in exec_override_text,
         "AI Agent exec override must not index cmdline with map-value cmdline_len directly; old verifiers reject the pointer arithmetic",