update: support new umount event pair

Signed-off-by: Andrea Terzolo <andrea.terzolo@polito.it>

driver/bpf/fillers.h

@@ -132,6 +132,7 @@ FILLER_RAW(terminate_filler)
 			case PPME_SYSCALL_MKDIRAT_E:
 			case PPME_SYSCALL_MOUNT_E:
 			case PPME_SYSCALL_UMOUNT_E:
+			case PPME_SYSCALL_UMOUNT_1_E:
 			case PPME_SYSCALL_RENAME_E:
 			case PPME_SYSCALL_RENAMEAT_E:
 			case PPME_SYSCALL_RENAMEAT2_E:
@@ -214,6 +215,7 @@ FILLER_RAW(terminate_filler)
 			case PPME_SYSCALL_MKDIRAT_X:
 			case PPME_SYSCALL_MOUNT_X:
 			case PPME_SYSCALL_UMOUNT_X:
+			case PPME_SYSCALL_UMOUNT_1_X:
 			case PPME_SYSCALL_RENAME_X:
 			case PPME_SYSCALL_RENAMEAT_X:
 			case PPME_SYSCALL_RENAMEAT2_X:
@@ -6137,6 +6139,18 @@ FILLER(sys_dup3_x, true)
 	return res;
 }
 
+FILLER(sys_umount_x, true)
+{
+	/* Parameter 1: ret (type: PT_FD) */
+	long retval = bpf_syscall_get_retval(data->ctx);
+	int res = bpf_val_to_ring_type(data, retval, PT_ERRNO);
+	CHECK_RES(res);
+
+	/* Parameter 2: name (type: PT_FSPATH) */
+	unsigned long target_pointer = bpf_syscall_get_argument(data, 0);
+	return  bpf_val_to_ring(data, target_pointer);
+}
+
 #ifdef CAPTURE_SCHED_PROC_EXEC
 /* We set `is_syscall` flag to `false` since this is not
  * a real syscall, we only send the same event from another

driver/event_table.c

@@ -270,7 +270,7 @@ const struct ppm_event_info g_event_info[] = {
 	[PPME_SYSCALL_PPOLL_X] = {"ppoll", EC_WAIT | EC_SYSCALL, EF_WAITS, 2, {{"res", PT_ERRNO, PF_DEC}, {"fds", PT_FDLIST, PF_DEC} } },
 	[PPME_SYSCALL_MOUNT_E] = {"mount", EC_FILE | EC_SYSCALL, EF_MODIFIES_STATE, 1, {{"flags", PT_FLAGS32, PF_HEX, mount_flags} } },
 	[PPME_SYSCALL_MOUNT_X] = {"mount", EC_FILE | EC_SYSCALL, EF_MODIFIES_STATE, 4, {{"res", PT_ERRNO, PF_DEC}, {"dev", PT_CHARBUF, PF_NA}, {"dir", PT_FSPATH, PF_NA}, {"type", PT_CHARBUF, PF_NA} } },
-	[PPME_SYSCALL_UMOUNT_E] = {"umount", EC_FILE | EC_SYSCALL, EF_MODIFIES_STATE, 1, {{"flags", PT_FLAGS32, PF_HEX, umount_flags} } }, // we need to create separate events for umount and umount2, umount doesn't have the flag parameter!!
+	[PPME_SYSCALL_UMOUNT_E] = {"umount", EC_FILE | EC_SYSCALL, EF_MODIFIES_STATE, 1, {{"flags", PT_FLAGS32, PF_HEX, umount_flags} } }, // right now this event pair is used by umount2 syscall, we need to create a new event pair `PPME_SYSCALL_UMOUNT2_E/PPME_SYSCALL_UMOUNT2_X` with name "umount2" we cannot change the name here otherwise we break scap-files compatibility.
 	[PPME_SYSCALL_UMOUNT_X] = {"umount", EC_FILE | EC_SYSCALL, EF_MODIFIES_STATE, 2, {{"res", PT_ERRNO, PF_DEC}, {"name", PT_FSPATH, PF_NA} } },
 	[PPME_K8S_E] = {"k8s", EC_INTERNAL | EC_METAEVENT, EF_SKIPPARSERESET | EF_MODIFIES_STATE, 1, {{"json", PT_CHARBUF, PF_NA} } },
 	[PPME_K8S_X] = {"NA", EC_UNKNOWN, EF_UNUSED, 0},
@@ -398,6 +398,8 @@ const struct ppm_event_info g_event_info[] = {
 	[PPME_SYSCALL_FCHOWN_X] = {"fchown", EC_FILE | EC_SYSCALL, EF_NONE, 4, {{"res", PT_ERRNO, PF_DEC}, {"fd", PT_FD, PF_DEC}, {"uid", PT_UINT32, PF_DEC}, {"gid", PT_UINT32, PF_DEC} } },
 	[PPME_SYSCALL_FCHOWNAT_E] = {"fchownat", EC_FILE | EC_SYSCALL, EF_NONE, 0},
 	[PPME_SYSCALL_FCHOWNAT_X] = {"fchownat", EC_FILE | EC_SYSCALL, EF_NONE, 6, {{"res", PT_ERRNO, PF_DEC}, {"dirfd", PT_FD, PF_DEC}, {"pathname", PT_FSRELPATH, PF_NA, DIRFD_PARAM(1)}, {"uid", PT_UINT32, PF_DEC}, {"gid", PT_UINT32, PF_DEC}, {"flags", PT_FLAGS32, PF_HEX, fchownat_flags}} },
+	[PPME_SYSCALL_UMOUNT_1_E] = {"umount", EC_FILE | EC_SYSCALL, EF_MODIFIES_STATE, 0},
+	[PPME_SYSCALL_UMOUNT_1_X] = {"umount", EC_FILE | EC_SYSCALL, EF_MODIFIES_STATE, 2, {{"res", PT_ERRNO, PF_DEC}, {"name", PT_FSPATH, PF_NA} } },
 
 	/* NB: Starting from scap version 1.2, event types will no longer be changed when an event is modified, and the only kind of change permitted for pre-existent events is adding parameters.
 	 *     New event types are allowed only for new syscalls or new internal events.

driver/fillers_table.c

@@ -340,4 +340,6 @@ const struct ppm_event_entry g_ppm_events[PPM_EVENT_MAX] = {
 	[PPME_SYSCALL_FCHOWN_X] = {FILLER_REF(sys_fchown_x)},
 	[PPME_SYSCALL_FCHOWNAT_E] = {FILLER_REF(sys_empty)},
 	[PPME_SYSCALL_FCHOWNAT_X] = {FILLER_REF(sys_fchownat_x)},
+	[PPME_SYSCALL_UMOUNT_1_E] = {FILLER_REF(sys_empty)},
+	[PPME_SYSCALL_UMOUNT_1_X] = {FILLER_REF(sys_umount_x)},
 };

driver/main.c

@@ -1475,6 +1475,7 @@ static inline void drops_buffer_syscall_categories_counters(ppm_event_code event
 	case PPME_SYSCALL_MKDIRAT_E:
 	case PPME_SYSCALL_MOUNT_E:
 	case PPME_SYSCALL_UMOUNT_E:
+	case PPME_SYSCALL_UMOUNT_1_E:
 	case PPME_SYSCALL_RENAME_E:
 	case PPME_SYSCALL_RENAMEAT_E:
 	case PPME_SYSCALL_RENAMEAT2_E:
@@ -1545,6 +1546,7 @@ static inline void drops_buffer_syscall_categories_counters(ppm_event_code event
 	case PPME_SYSCALL_MKDIRAT_X:
 	case PPME_SYSCALL_MOUNT_X:
 	case PPME_SYSCALL_UMOUNT_X:
+	case PPME_SYSCALL_UMOUNT_1_X:
 	case PPME_SYSCALL_RENAME_X:
 	case PPME_SYSCALL_RENAMEAT_X:
 	case PPME_SYSCALL_RENAMEAT2_X:

driver/modern_bpf/definitions/events_dimensions.h

@@ -103,6 +103,7 @@
 #define UNSHARE_X_SIZE HEADER_LEN + sizeof(int64_t) + PARAM_LEN
 #define MOUNT_E_SIZE HEADER_LEN + sizeof(uint32_t) + PARAM_LEN
 #define UMOUNT2_E_SIZE HEADER_LEN + sizeof(uint32_t) + PARAM_LEN
+#define UMOUNT_E_SIZE HEADER_LEN
 #define LINK_E_SIZE HEADER_LEN
 #define LINKAT_E_SIZE HEADER_LEN
 #define SYMLINK_E_SIZE HEADER_LEN

driver/modern_bpf/programs/tail_called/events/syscall_dispatched_events/umount.bpf.c

@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2023 The Falco Authors.
+ *
+ * This file is dual licensed under either the MIT or GPL 2. See MIT.txt
+ * or GPL2.txt for full copies of the license.
+ */
+
+#include <helpers/interfaces/fixed_size_event.h>
+#include <helpers/interfaces/variable_size_event.h>
+
+/*=============================== ENTER EVENT ===========================*/
+
+SEC("tp_btf/sys_enter")
+int BPF_PROG(umount_e,
+	     struct pt_regs *regs,
+	     long id)
+{
+	struct ringbuf_struct ringbuf;
+	if(!ringbuf__reserve_space(&ringbuf, UMOUNT_E_SIZE))
+	{
+		return 0;
+	}
+
+	ringbuf__store_event_header(&ringbuf, PPME_SYSCALL_UMOUNT_1_E);
+
+	/*=============================== COLLECT PARAMETERS  ===========================*/
+
+	// Here we have no parameters to collect.
+
+	/*=============================== COLLECT PARAMETERS  ===========================*/
+
+	ringbuf__submit_event(&ringbuf);
+
+	return 0;
+}
+
+/*=============================== ENTER EVENT ===========================*/
+
+/*=============================== EXIT EVENT ===========================*/
+
+SEC("tp_btf/sys_exit")
+int BPF_PROG(umount_x,
+	     struct pt_regs *regs,
+	     long ret)
+{
+	struct auxiliary_map *auxmap = auxmap__get();
+	if(!auxmap)
+	{
+		return 0;
+	}
+
+	auxmap__preload_event_header(auxmap, PPME_SYSCALL_UMOUNT_1_X);
+
+	/*=============================== COLLECT PARAMETERS  ===========================*/
+
+	/* Parameter 1: res (type: PT_ERRNO) */
+	auxmap__store_s64_param(auxmap, ret);
+
+	/* Parameter 2: name (type: PT_FSPATH) */
+	unsigned long target_pointer = extract__syscall_argument(regs, 0);
+	auxmap__store_charbuf_param(auxmap, target_pointer, MAX_PATH, USER);
+
+	/*=============================== COLLECT PARAMETERS  ===========================*/
+
+	auxmap__finalize_event_header(auxmap);
+
+	auxmap__submit_event(auxmap);
+
+	return 0;
+}
+
+/*=============================== EXIT EVENT ===========================*/

driver/ppm_events_public.h

@@ -1188,7 +1188,9 @@ typedef enum {
 	PPME_SYSCALL_FCHOWN_X = 383,
 	PPME_SYSCALL_FCHOWNAT_E = 384,
 	PPME_SYSCALL_FCHOWNAT_X = 385,
-	PPM_EVENT_MAX = 386
+	PPME_SYSCALL_UMOUNT_1_E = 386,
+	PPME_SYSCALL_UMOUNT_1_X = 387,
+	PPM_EVENT_MAX = 388
 } ppm_event_code;
 /*@}*/
 

driver/ppm_fillers.c

@@ -6985,6 +6985,25 @@ int f_sys_splice_e(struct event_filler_arguments *args)
 	return add_sentinel(args);
 }
 
+int f_sys_umount_x(struct event_filler_arguments *args)
+{
+	unsigned long val;
+	int res;
+	int64_t retval;
+
+	/* Parameter 1: res (type: PT_ERRNO) */
+	retval = (int64_t)syscall_get_return_value(current, args->regs);
+	res = val_to_ring(args, retval, 0, false, 0);
+	CHECK_RES(res);
+
+	/* Parameter 2: name (type: PT_FSPATH) */
+	syscall_get_arguments_deprecated(current, args->regs, 0, 1, &val);
+	res = val_to_ring(args, val, 0, true, 0);
+	CHECK_RES(res);
+
+	return add_sentinel(args);
+}
+
 #ifdef CAPTURE_SCHED_PROC_EXEC
 int f_sched_prog_exec(struct event_filler_arguments *args)
 {

driver/ppm_fillers.h

@@ -156,6 +156,7 @@ or GPL2.txt for full copies of the license.
 	FN(sys_recvmsg_e)                 \
 	FN(sys_signalfd_e)                 \
 	FN(sys_splice_e)				\
+	FN(sys_umount_x)				\
 	FN(terminate_filler)
 
 #define FILLER_ENUM_FN(x) PPM_FILLER_##x,

driver/syscall_table.c

@@ -425,7 +425,7 @@ const struct syscall_evt_pair g_syscall_table[SYSCALL_TABLE_SIZE] = {
 	[__NR_lstat64 - SYSCALL_TABLE_ID0] = {UF_USED, PPME_SYSCALL_LSTAT64_E, PPME_SYSCALL_LSTAT64_X, PPM_SC_LSTAT64},
 #endif
 #ifdef __NR_umount
-	[__NR_umount - SYSCALL_TABLE_ID0] = {UF_USED, PPME_SYSCALL_UMOUNT_E, PPME_SYSCALL_UMOUNT_X, PPM_SC_UMOUNT},
+	[__NR_umount - SYSCALL_TABLE_ID0] = {UF_USED, PPME_SYSCALL_UMOUNT_1_E, PPME_SYSCALL_UMOUNT_1_X, PPM_SC_UMOUNT},
 #endif
 #ifdef __NR_recv
 	[__NR_recv - SYSCALL_TABLE_ID0] = {UF_USED, PPME_SOCKET_RECV_E, PPME_SOCKET_RECV_X, PPM_SC_RECV},
@@ -1238,7 +1238,7 @@ const struct syscall_evt_pair g_syscall_ia32_table[SYSCALL_TABLE_SIZE] = {
 	[__NR_ia32_lstat64 - SYSCALL_TABLE_ID0] = {UF_USED, PPME_SYSCALL_LSTAT64_E, PPME_SYSCALL_LSTAT64_X, PPM_SC_LSTAT64},
 #endif
 #ifdef __NR_ia32_umount
-	[__NR_ia32_umount - SYSCALL_TABLE_ID0] = {UF_USED, PPME_SYSCALL_UMOUNT_E, PPME_SYSCALL_UMOUNT_X, PPM_SC_UMOUNT},
+	[__NR_ia32_umount - SYSCALL_TABLE_ID0] = {UF_USED, PPME_SYSCALL_UMOUNT_1_E, PPME_SYSCALL_UMOUNT_1_X, PPM_SC_UMOUNT},
 #endif
 #ifdef __NR_ia32_recv
 	[__NR_ia32_recv - SYSCALL_TABLE_ID0] = {UF_USED, PPME_SOCKET_RECV_E, PPME_SOCKET_RECV_X, PPM_SC_RECV},

test/drivers/test_suites/syscall_enter_suite/umount_e.cpp

@@ -0,0 +1,39 @@
+#include "../../event_class/event_class.h"
+
+#ifdef __NR_umount
+
+TEST(SyscallEnter, umountE)
+{
+	auto evt_test = get_syscall_event_test(__NR_umount, ENTER_EVENT);
+
+	evt_test->enable_capture();
+
+	/*=============================== TRIGGER SYSCALL ===========================*/
+
+	const char* target = "//**null-file-path**//";
+	assert_syscall_state(SYSCALL_FAILURE, "umount", syscall(__NR_umount, target));
+
+	/*=============================== TRIGGER SYSCALL ===========================*/
+
+	evt_test->disable_capture();
+
+	evt_test->assert_event_presence();
+
+	if(HasFatalFailure())
+	{
+		return;
+	}
+
+	evt_test->parse_event();
+
+	evt_test->assert_header();
+
+	/*=============================== ASSERT PARAMETERS  ===========================*/
+
+	// Here we have no parameters to assert.
+
+	/*=============================== ASSERT PARAMETERS  ===========================*/
+
+	evt_test->assert_num_params_pushed(0);
+}
+#endif

test/drivers/test_suites/syscall_exit_suite/umount_x.cpp

@@ -0,0 +1,44 @@
+#include "../../event_class/event_class.h"
+
+#ifdef __NR_umount
+
+TEST(SyscallExit, umountX)
+{
+	auto evt_test = get_syscall_event_test(__NR_umount, EXIT_EVENT);
+
+	evt_test->enable_capture();
+
+	/*=============================== TRIGGER SYSCALL ===========================*/
+
+	const char* target = "//**null-file-path**//";
+	assert_syscall_state(SYSCALL_FAILURE, "umount", syscall(__NR_umount, target));
+	int64_t errno_value = -errno;
+
+	/*=============================== TRIGGER SYSCALL ===========================*/
+
+	evt_test->disable_capture();
+
+	evt_test->assert_event_presence();
+
+	if(HasFatalFailure())
+	{
+		return;
+	}
+
+	evt_test->parse_event();
+
+	evt_test->assert_header();
+
+	/*=============================== ASSERT PARAMETERS  ===========================*/
+
+	/* Parameter 1: res (type: PT_ERRNO) */
+	evt_test->assert_numeric_param(1, (int64_t)errno_value);
+
+	/* Parameter 2: name (type: PT_FSPATH) */
+	evt_test->assert_charbuf_param(2, target);
+
+	/*=============================== ASSERT PARAMETERS  ===========================*/
+
+	evt_test->assert_num_params_pushed(2);
+}
+#endif

userspace/libpman/src/events_prog_names.h

@@ -259,6 +259,8 @@ static const char* event_prog_names[PPM_EVENT_MAX] = {
 	[PPME_SYSCALL_FCHOWN_X] = "fchown_x",
 	[PPME_SYSCALL_FCHOWNAT_E] = "fchownat_e",
 	[PPME_SYSCALL_FCHOWNAT_X] = "fchownat_x",
+	[PPME_SYSCALL_UMOUNT_1_E] = "umount_e",
+	[PPME_SYSCALL_UMOUNT_1_X] = "umount_x",
 };
 
 /* Some events can require more than one bpf program to collect all the data. */

userspace/libsinsp/test/events_file.ut.cpp

@@ -183,3 +183,17 @@ TEST_F(sinsp_with_test_input, creates_fd_generic)
 	ASSERT_EQ(get_field_as_string(evt, "fd.num"), "4");
 }
 
+TEST_F(sinsp_with_test_input, umount)
+{
+	add_default_init_thread();
+
+	open_inspector();
+	sinsp_evt* evt = NULL;
+
+	add_event_advance_ts(increasing_ts(), 1, PPME_SYSCALL_UMOUNT_1_E, 0);
+	evt = add_event_advance_ts(increasing_ts(), 1, PPME_SYSCALL_UMOUNT_1_X, 2, 0, "/target_name");
+	ASSERT_EQ(get_field_as_string(evt, "evt.type"), "umount");
+	ASSERT_EQ(get_field_as_string(evt, "evt.category"), "file");
+	ASSERT_EQ(get_field_as_string(evt, "evt.arg.res"), "0");
+	ASSERT_EQ(get_field_as_string(evt, "evt.arg.name"), "/target_name");
+}

userspace/libsinsp/test/table/event_table.cpp

@@ -2,7 +2,7 @@
 #include <sinsp.h>
 
 /* These numbers must be updated when we add new events */
-#define SYSCALL_EVENTS_NUM 340
+#define SYSCALL_EVENTS_NUM 342
 #define TRACEPOINT_EVENTS_NUM 6
 #define METAEVENTS_NUM 19
 #define PLUGIN_EVENTS_NUM 1