cleanup: move custom tail calls in sys_exit

Signed-off-by: Andrea Terzolo <[email protected]>

driver/modern_bpf/programs/attached/dispatchers/syscall_exit.bpf.c

@@ -8,6 +8,119 @@
 
 #include <helpers/interfaces/syscalls_dispatcher.h>
 #include <bpf/bpf_helpers.h>
+#include <helpers/interfaces/fixed_size_event.h>
+
+SEC("tp_btf/sys_exit")
+int BPF_PROG(t_hotplug) {
+	/* We assume that the ring buffer for CPU 0 is always there so we send the
+	 * HOT-PLUG event through this buffer.
+	 */
+	uint32_t cpu_0 = 0;
+	struct ringbuf_map *rb = bpf_map_lookup_elem(&ringbuf_maps, &cpu_0);
+	if(!rb) {
+		bpf_printk("unable to obtain the ring buffer for CPU 0");
+		return 0;
+	}
+
+	struct counter_map *counter = bpf_map_lookup_elem(&counter_maps, &cpu_0);
+	if(!counter) {
+		bpf_printk("unable to obtain the counter map for CPU 0");
+		return 0;
+	}
+
+	/* This counts the event seen by the drivers even if they are dropped because the buffer is
+	 * full. */
+	counter->n_evts++;
+
+	/* If we are not able to reserve space we stop here
+	 * the event collection.
+	 */
+	struct ringbuf_struct ringbuf;
+	ringbuf.reserved_event_size = HOTPLUG_E_SIZE;
+	ringbuf.event_type = PPME_CPU_HOTPLUG_E;
+	ringbuf.data = bpf_ringbuf_reserve(rb, HOTPLUG_E_SIZE, 0);
+	if(!ringbuf.data) {
+		counter->n_drops_buffer++;
+		return 0;
+	}
+
+	ringbuf__store_event_header(&ringbuf);
+
+	/*=============================== COLLECT PARAMETERS ===========================*/
+
+	/* Parameter 1: cpu (type: PT_UINT32) */
+	uint32_t current_cpu_id = (uint32_t)bpf_get_smp_processor_id();
+	ringbuf__store_u32(&ringbuf, current_cpu_id);
+
+	/* Parameter 2: action (type: PT_UINT32) */
+	/* Right now we don't have actions we always send 0 */
+	ringbuf__store_u32(&ringbuf, 0);
+
+	/*=============================== COLLECT PARAMETERS ===========================*/
+
+	ringbuf__submit_event(&ringbuf);
+	return 0;
+}
+
+SEC("tp_btf/sys_exit")
+int BPF_PROG(t_drop_e) {
+	struct ringbuf_struct ringbuf;
+	if(!ringbuf__reserve_space(&ringbuf, DROP_E_SIZE, PPME_DROP_E)) {
+		return 0;
+	}
+
+	ringbuf__store_event_header(&ringbuf);
+
+	/*=============================== COLLECT PARAMETERS ===========================*/
+
+	ringbuf__store_u32(&ringbuf, maps__get_sampling_ratio());
+
+	/*=============================== COLLECT PARAMETERS ===========================*/
+
+	ringbuf__submit_event(&ringbuf);
+	return 0;
+}
+
+SEC("tp_btf/sys_exit")
+int BPF_PROG(t_drop_x) {
+	struct ringbuf_struct ringbuf;
+	if(!ringbuf__reserve_space(&ringbuf, DROP_X_SIZE, PPME_DROP_X)) {
+		return 0;
+	}
+
+	ringbuf__store_event_header(&ringbuf);
+
+	/*=============================== COLLECT PARAMETERS ===========================*/
+
+	ringbuf__store_u32(&ringbuf, maps__get_sampling_ratio());
+
+	/*=============================== COLLECT PARAMETERS ===========================*/
+
+	ringbuf__submit_event(&ringbuf);
+	return 0;
+}
+
+enum custom_sys_exit_logic_codes {
+	T_HOTPLUG,
+	T_DROP_E,
+	T_DROP_X,
+	// add more codes here.
+	T_CUSTOM_MAX,
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+	__uint(max_entries, T_CUSTOM_MAX);
+	__uint(key_size, sizeof(__u32));
+	__array(values, int(void *));
+} custom_sys_exit_calls SEC(".maps") = {
+        .values =
+                {
+                        [T_HOTPLUG] = (void *)&t_hotplug,
+                        [T_DROP_E] = (void *)&t_drop_e,
+                        [T_DROP_X] = (void *)&t_drop_x,
+                },
+};
 
 static __always_inline bool sampling_logic_exit(void *ctx, uint32_t id) {
 	/* If dropping mode is not enabled we don't perform any sampling
@@ -39,15 +152,15 @@ static __always_inline bool sampling_logic_exit(void *ctx, uint32_t id) {
 			 * an iteration we will synchronize again the next time the logic is enabled.
 			 */
 			maps__set_is_dropping(true);
-			bpf_tail_call(ctx, &extra_syscall_calls, T1_DROP_E);
+			bpf_tail_call(ctx, &custom_sys_exit_calls, T_DROP_E);
 			bpf_printk("unable to tail call into 'drop_e' prog");
 		}
 		return true;
 	}
 
 	if(maps__get_is_dropping()) {
 		maps__set_is_dropping(false);
-		bpf_tail_call(ctx, &extra_syscall_calls, T1_DROP_X);
+		bpf_tail_call(ctx, &custom_sys_exit_calls, T_DROP_X);
 		bpf_printk("unable to tail call into 'drop_x' prog");
 	}
 
@@ -120,7 +233,7 @@ int BPF_PROG(sys_exit, struct pt_regs *regs, long ret) {
 	// we change our architecture we may need to update this logic.
 	struct ringbuf_map *rb = maps__get_ringbuf_map();
 	if(!rb) {
-		bpf_tail_call(ctx, &extra_syscall_calls, T1_HOTPLUG_E);
+		bpf_tail_call(ctx, &custom_sys_exit_calls, T_HOTPLUG);
 		bpf_printk("failed to tail call into the 'hotplug' prog");
 		return 0;
 	}

driver/ppm_events_public.h

@@ -1536,9 +1536,6 @@ enum extra_syscall_codes {
 	T2_CLONE3_X,
 	T2_FORK_X,
 	T2_VFORK_X,
-	T1_DROP_E,
-	T1_DROP_X,
-	T1_HOTPLUG_E,
 	T1_OPEN_BY_HANDLE_AT_X,
 	T2_EXECVE_X,
 	T2_EXECVEAT_X,

userspace/libpman/src/events_prog_names.h

@@ -353,9 +353,6 @@ static const char* extra_event_prog_names[TAIL_EXTRA_EVENT_PROG_MAX] = {
         [T2_CLONE3_X] = "t2_clone3_x",
         [T2_FORK_X] = "t2_fork_x",
         [T2_VFORK_X] = "t2_vfork_x",
-        [T1_DROP_E] = "t1_drop_e",
-        [T1_DROP_X] = "t1_drop_x",
-        [T1_HOTPLUG_E] = "t1_hotplug_e",
         [T1_OPEN_BY_HANDLE_AT_X] = "t1_open_by_handle_at_x",
         [T2_EXECVE_X] = "t2_execve_x",
         [T2_EXECVEAT_X] = "t2_execveat_x",