tetragon: Mark some execve functions with __arg_ctx

When calling this functions from other projects, they stay global and it's important the verifier knows which argment is context. Adding also other argument related declaration tags. Signed-off-by: Jiri Olsa <[email protected]>
cilium · Oct 19, 2024 · f60dee8 · f60dee8
1 parent 05716de
commit f60dee8
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Showing 2 changed files with 16 additions and 2 deletions.
diff --git a/bpf/lib/common.h b/bpf/lib/common.h
@@ -62,4 +62,18 @@ struct bpf_map_def {
 #define DEBUG(__fmt, ...)
 #endif
 
+#ifdef __V61_BPF_PROG
+#define __arg_ctx      __attribute__((btf_decl_tag("arg:ctx")))
+#define __arg_nonnull  __attribute((btf_decl_tag("arg:nonnull")))
+#define __arg_nullable __attribute((btf_decl_tag("arg:nullable")))
+#define __arg_trusted  __attribute((btf_decl_tag("arg:trusted")))
+#define __arg_arena    __attribute((btf_decl_tag("arg:arena")))
+#else
+#define __arg_ctx
+#define __arg_nonnull
+#define __arg_nullable
+#define __arg_trusted
+#define __arg_arena
+#endif // __V61_BPF_PROG
+
 #endif // _MSG_COMMON__
diff --git a/bpf/process/bpf_execve_event.c b/bpf/process/bpf_execve_event.c
@@ -284,7 +284,7 @@ event_execve(struct trace_event_raw_sched_process_exec *ctx)
 }
 
 __attribute__((section("tracepoint"), used)) int
-execve_rate(void *ctx)
+execve_rate(void *ctx __arg_ctx)
 {
 	struct msg_execve_event *msg;
 	__u32 zero = 0;
@@ -329,7 +329,7 @@ void update_mb_bitset(struct binary *bin)
  * has already been collected, then send it to the perf buffer.
  */
 __attribute__((section("tracepoint"), used)) int
-execve_send(void *ctx)
+execve_send(void *ctx __arg_ctx)
 {
 	struct msg_execve_event *event;
 	struct execve_map_value *curr;