From: Mathieu Desnoyers Date: Thu, 19 Nov 2020 16:41:11 +0000 (-0500) Subject: Revert "Implement event notifiers for syscalls" X-Git-Tag: v2.13.0-rc1~125 X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=3b783111546e16bf005f63f316551e868cae7e1e;p=lttng-modules.git Revert "Implement event notifiers for syscalls" This reverts commit 8ced8896fe832af52b749d429b8eceb872a83d1b. This commit was not ready and was committed by error. Signed-off-by: Mathieu Desnoyers --- diff --git a/include/instrumentation/syscalls/headers/syscalls_unknown.h b/include/instrumentation/syscalls/headers/syscalls_unknown.h index 38add19f..64e53792 100644 --- a/include/instrumentation/syscalls/headers/syscalls_unknown.h +++ b/include/instrumentation/syscalls/headers/syscalls_unknown.h @@ -28,26 +28,6 @@ LTTNG_TRACEPOINT_EVENT(compat_syscall_entry_unknown, ) ) -#undef TP_PROBE_CB -#define TP_PROBE_CB(_template) &syscall_entry_event_notifier_probe - -LTTNG_TRACEPOINT_EVENT(syscall_notifier_entry_unknown, - TP_PROTO(int id, unsigned long *args), - TP_ARGS(id, args), - TP_FIELDS( - ctf_integer(int, id, id) - ctf_array(unsigned long, args, args, UNKNOWN_SYSCALL_NRARGS) - ) -) -LTTNG_TRACEPOINT_EVENT(compat_syscall_notifier_entry_unknown, - TP_PROTO(int id, unsigned long *args), - TP_ARGS(id, args), - TP_FIELDS( - ctf_integer(int, id, id) - ctf_array(unsigned long, args, args, UNKNOWN_SYSCALL_NRARGS) - ) -) - #undef TP_PROBE_CB #define TP_PROBE_CB(_template) &syscall_exit_event_probe diff --git a/include/lttng/events.h b/include/lttng/events.h index 61d37d70..bee47105 100644 --- a/include/lttng/events.h +++ b/include/lttng/events.h @@ -299,12 +299,6 @@ enum lttng_syscall_abi { LTTNG_SYSCALL_ABI_COMPAT, }; -struct lttng_syscall { - struct list_head node; /* chain registered syscall event_notifier */ - unsigned int syscall_id; - bool is_compat; -}; - /* * lttng_event structure is referred to by the tracing fast path. It must be * kept small. @@ -357,7 +351,6 @@ struct lttng_event_notifier { union { struct lttng_kprobe kprobe; struct lttng_uprobe uprobe; - struct lttng_syscall syscall; } u; /* Backward references: list of lttng_enabler_ref (ref to enablers) */ @@ -636,12 +629,6 @@ struct lttng_event_notifier_group { struct lib_ring_buffer *buf; /* Ring buffer for event notifier group. */ wait_queue_head_t read_wait; struct irq_work wakeup_pending; /* Pending wakeup irq work. */ - - struct list_head *event_notifier_syscall_dispatch; - struct list_head *event_notifier_compat_syscall_dispatch; - - unsigned int syscall_all:1, - sys_enter_registered:1; }; struct lttng_metadata_cache { @@ -783,9 +770,6 @@ int lttng_session_list_tracker_ids(struct lttng_session *session, void lttng_clock_ref(void); void lttng_clock_unref(void); -int lttng_desc_match_enabler(const struct lttng_event_desc *desc, - struct lttng_enabler *enabler); - #if defined(CONFIG_HAVE_SYSCALL_TRACEPOINTS) int lttng_syscalls_register_event(struct lttng_channel *chan, void *filter); int lttng_syscalls_unregister_event(struct lttng_channel *chan); @@ -797,14 +781,6 @@ int lttng_syscall_filter_disable_event(struct lttng_channel *chan, long lttng_channel_syscall_mask(struct lttng_channel *channel, struct lttng_kernel_syscall_mask __user *usyscall_mask); -int lttng_syscalls_register_event_notifier( - struct lttng_event_notifier_enabler *event_notifier_enabler, - void *filter); -int lttng_syscals_create_matching_event_notifiers( - struct lttng_event_notifier_enabler *event_notifier_enabler, void *filter); -int lttng_syscalls_unregister_event_notifier(struct lttng_event_notifier_group *group); -int lttng_syscall_filter_enable_event_notifier(struct lttng_event_notifier *event_notifier); -int lttng_syscall_filter_disable_event_notifier(struct lttng_event_notifier *event_notifier); #else static inline int lttng_syscalls_register_event( struct lttng_channel *chan, void *filter) @@ -840,32 +816,6 @@ static inline long lttng_channel_syscall_mask(struct lttng_channel *channel, return -ENOSYS; } -static inline int lttng_syscalls_register_event_notifier( - struct lttng_event_notifier_group *group, void *filter) -{ - return -ENOSYS; -} - -static inline int lttng_syscalls_unregister_event_notifier( - struct lttng_event_notifier_group *group) -{ - return 0; -} - -static inline int lttng_syscall_filter_enable_event_notifier( - struct lttng_event_notifier_group *group, - const char *name) -{ - return -ENOSYS; -} - -static inline int lttng_syscall_filter_disable_event_notifier( - struct lttng_event_notifier_group *group, - const char *name) -{ - return -ENOSYS; -} - #endif void lttng_filter_sync_state(struct lttng_bytecode_runtime *runtime); diff --git a/src/lttng-abi.c b/src/lttng-abi.c index 68ea7ac3..f9e4422d 100644 --- a/src/lttng-abi.c +++ b/src/lttng-abi.c @@ -1824,12 +1824,11 @@ int lttng_abi_create_event_notifier(struct file *event_notifier_group_file, case LTTNG_KERNEL_KPROBE: event_notifier_param->event.u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; break; - case LTTNG_KERNEL_SYSCALL: - break; case LTTNG_KERNEL_KRETPROBE: /* Placing an event notifier on kretprobe is not supported. */ case LTTNG_KERNEL_FUNCTION: case LTTNG_KERNEL_NOOP: + case LTTNG_KERNEL_SYSCALL: default: ret = -EINVAL; goto inval_instr; diff --git a/src/lttng-events.c b/src/lttng-events.c index 176c3832..41fea850 100644 --- a/src/lttng-events.c +++ b/src/lttng-events.c @@ -329,9 +329,6 @@ void lttng_event_notifier_group_destroy( mutex_lock(&sessions_mutex); - ret = lttng_syscalls_unregister_event_notifier(event_notifier_group); - WARN_ON(ret); - list_for_each_entry_safe(event_notifier, tmpevent_notifier, &event_notifier_group->event_notifiers_head, list) { ret = _lttng_event_notifier_unregister(event_notifier); @@ -615,13 +612,13 @@ int lttng_event_notifier_enable(struct lttng_event_notifier *event_notifier) } switch (event_notifier->instrumentation) { case LTTNG_KERNEL_TRACEPOINT: - case LTTNG_KERNEL_SYSCALL: ret = -EINVAL; break; case LTTNG_KERNEL_KPROBE: case LTTNG_KERNEL_UPROBE: WRITE_ONCE(event_notifier->enabled, 1); break; + case LTTNG_KERNEL_SYSCALL: case LTTNG_KERNEL_FUNCTION: case LTTNG_KERNEL_NOOP: case LTTNG_KERNEL_KRETPROBE: @@ -645,13 +642,13 @@ int lttng_event_notifier_disable(struct lttng_event_notifier *event_notifier) } switch (event_notifier->instrumentation) { case LTTNG_KERNEL_TRACEPOINT: - case LTTNG_KERNEL_SYSCALL: ret = -EINVAL; break; case LTTNG_KERNEL_KPROBE: case LTTNG_KERNEL_UPROBE: WRITE_ONCE(event_notifier->enabled, 0); break; + case LTTNG_KERNEL_SYSCALL: case LTTNG_KERNEL_FUNCTION: case LTTNG_KERNEL_NOOP: case LTTNG_KERNEL_KRETPROBE: @@ -1012,12 +1009,12 @@ struct lttng_event_notifier *_lttng_event_notifier_create( break; case LTTNG_KERNEL_KPROBE: case LTTNG_KERNEL_UPROBE: - case LTTNG_KERNEL_SYSCALL: event_name = event_notifier_param->event.name; break; case LTTNG_KERNEL_KRETPROBE: case LTTNG_KERNEL_FUNCTION: case LTTNG_KERNEL_NOOP: + case LTTNG_KERNEL_SYSCALL: default: WARN_ON_ONCE(1); ret = -EINVAL; @@ -1089,20 +1086,6 @@ struct lttng_event_notifier *_lttng_event_notifier_create( ret = try_module_get(event_notifier->desc->owner); WARN_ON_ONCE(!ret); break; - case LTTNG_KERNEL_NOOP: - case LTTNG_KERNEL_SYSCALL: - /* - * Needs to be explicitly enabled after creation, since - * we may want to apply filters. - */ - event_notifier->enabled = 0; - event_notifier->registered = 0; - event_notifier->desc = event_desc; - if (!event_notifier->desc) { - ret = -EINVAL; - goto register_error; - } - break; case LTTNG_KERNEL_UPROBE: /* * Needs to be explicitly enabled after creation, since @@ -1128,6 +1111,8 @@ struct lttng_event_notifier *_lttng_event_notifier_create( break; case LTTNG_KERNEL_KRETPROBE: case LTTNG_KERNEL_FUNCTION: + case LTTNG_KERNEL_NOOP: + case LTTNG_KERNEL_SYSCALL: default: WARN_ON_ONCE(1); ret = -EINVAL; @@ -1272,13 +1257,11 @@ void register_event_notifier(struct lttng_event_notifier *event_notifier) desc->event_notifier_callback, event_notifier); break; - case LTTNG_KERNEL_SYSCALL: - ret = lttng_syscall_filter_enable_event_notifier(event_notifier); - break; case LTTNG_KERNEL_KPROBE: case LTTNG_KERNEL_UPROBE: ret = 0; break; + case LTTNG_KERNEL_SYSCALL: case LTTNG_KERNEL_KRETPROBE: case LTTNG_KERNEL_FUNCTION: case LTTNG_KERNEL_NOOP: @@ -1314,11 +1297,9 @@ int _lttng_event_notifier_unregister( lttng_uprobes_unregister_event_notifier(event_notifier); ret = 0; break; - case LTTNG_KERNEL_SYSCALL: - ret = lttng_syscall_filter_disable_event_notifier(event_notifier); - break; case LTTNG_KERNEL_KRETPROBE: case LTTNG_KERNEL_FUNCTION: + case LTTNG_KERNEL_SYSCALL: case LTTNG_KERNEL_NOOP: default: WARN_ON_ONCE(1); @@ -1376,15 +1357,14 @@ void _lttng_event_notifier_destroy(struct lttng_event_notifier *event_notifier) module_put(event_notifier->desc->owner); lttng_kprobes_destroy_event_notifier_private(event_notifier); break; - case LTTNG_KERNEL_NOOP: - case LTTNG_KERNEL_SYSCALL: - break; case LTTNG_KERNEL_UPROBE: module_put(event_notifier->desc->owner); lttng_uprobes_destroy_event_notifier_private(event_notifier); break; case LTTNG_KERNEL_KRETPROBE: case LTTNG_KERNEL_FUNCTION: + case LTTNG_KERNEL_NOOP: + case LTTNG_KERNEL_SYSCALL: default: WARN_ON_ONCE(1); } @@ -1667,6 +1647,7 @@ int lttng_match_enabler_name(const char *desc_name, return 1; } +static int lttng_desc_match_enabler(const struct lttng_event_desc *desc, struct lttng_enabler *enabler) { @@ -1920,17 +1901,6 @@ void lttng_create_syscall_event_if_missing(struct lttng_event_enabler *event_ena WARN_ON_ONCE(ret); } -static -void lttng_create_syscall_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler) -{ - int ret; - - ret = lttng_syscalls_register_event_notifier(event_notifier_enabler, NULL); - WARN_ON_ONCE(ret); - ret = lttng_syscals_create_matching_event_notifiers(event_notifier_enabler, NULL); - WARN_ON_ONCE(ret); -} - /* * Create struct lttng_event if it is missing and present in the list of * tracepoint probes. @@ -2025,9 +1995,6 @@ void lttng_create_event_notifier_if_missing(struct lttng_event_notifier_enabler case LTTNG_KERNEL_TRACEPOINT: lttng_create_tracepoint_event_notifier_if_missing(event_notifier_enabler); break; - case LTTNG_KERNEL_SYSCALL: - lttng_create_syscall_event_notifier_if_missing(event_notifier_enabler); - break; default: WARN_ON_ONCE(1); break; diff --git a/src/lttng-syscalls.c b/src/lttng-syscalls.c index c18a1418..3139a556 100644 --- a/src/lttng-syscalls.c +++ b/src/lttng-syscalls.c @@ -29,7 +29,6 @@ #include #include #include -#include #ifndef CONFIG_COMPAT # ifndef is_compat_task @@ -64,10 +63,6 @@ void syscall_entry_event_probe(void *__data, struct pt_regs *regs, long id); static void syscall_exit_event_probe(void *__data, struct pt_regs *regs, long ret); -static -void syscall_entry_event_notifier_probe(void *__data, struct pt_regs *regs, - long id); - /* * Forward declarations for old kernels. */ @@ -290,7 +285,6 @@ typedef __kernel_old_time_t time_t; struct trace_syscall_entry { void *event_func; - void *event_notifier_func; const struct lttng_event_desc *desc; const struct lttng_event_field *fields; unsigned int nrargs; @@ -307,7 +301,6 @@ struct trace_syscall_entry { #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ [ _nr ] = { \ .event_func = __event_probe__syscall_entry_##_template, \ - .event_notifier_func = __event_notifier_probe__syscall_entry_##_template, \ .nrargs = (_nrargs), \ .fields = __event_fields___syscall_entry_##_template, \ .desc = &__event_desc___syscall_entry_##_name, \ @@ -323,7 +316,6 @@ static const struct trace_syscall_entry sc_table[] = { #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ [ _nr ] = { \ .event_func = __event_probe__compat_syscall_entry_##_template, \ - .event_notifier_func = __event_notifier_probe__compat_syscall_entry_##_template, \ .nrargs = (_nrargs), \ .fields = __event_fields___compat_syscall_entry_##_template, \ .desc = &__event_desc___compat_syscall_entry_##_name, \ @@ -346,7 +338,6 @@ const struct trace_syscall_entry compat_sc_table[] = { #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ [ _nr ] = { \ .event_func = __event_probe__syscall_exit_##_template, \ - .event_notifier_func = __event_notifier_probe__syscall_exit_##_template, \ .nrargs = (_nrargs), \ .fields = __event_fields___syscall_exit_##_template, \ .desc = &__event_desc___syscall_exit_##_name, \ @@ -362,7 +353,6 @@ static const struct trace_syscall_entry sc_exit_table[] = { #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ [ _nr ] = { \ .event_func = __event_probe__compat_syscall_exit_##_template, \ - .event_notifier_func = __event_notifier_probe__compat_syscall_exit_##_template, \ .nrargs = (_nrargs), \ .fields = __event_fields___compat_syscall_exit_##_template, \ .desc = &__event_desc___compat_syscall_exit_##_name, \ @@ -397,20 +387,6 @@ static void syscall_entry_event_unknown(struct lttng_event *event, __event_probe__syscall_entry_unknown(event, id, args); } -static void syscall_entry_event_notifier_unknown( - struct lttng_event_notifier_group *notifier_group, - struct pt_regs *regs, unsigned int id) -{ - unsigned long args[LTTNG_SYSCALL_NR_ARGS]; - struct lttng_event *event; - - lttng_syscall_get_arguments(current, regs, args); - if (unlikely(in_compat_syscall())) - __event_probe__compat_syscall_notifier_entry_unknown(event, id, args); - else - __event_probe__syscall_notifier_entry_unknown(event, id, args); -} - static __always_inline void syscall_entry_call_func(void *func, unsigned int nrargs, void *data, struct pt_regs *regs) @@ -550,44 +526,6 @@ void syscall_entry_event_probe(void *__data, struct pt_regs *regs, long id) syscall_entry_call_func(entry->event_func, entry->nrargs, event, regs); } -void syscall_entry_event_notifier_probe(void *__data, struct pt_regs *regs, long id) -{ - struct lttng_event_notifier_group *event_notifier_group = __data; - const struct trace_syscall_entry *entry; - struct list_head *dispatch_list; - struct lttng_event_notifier *iter; - size_t table_len; - - if (unlikely(in_compat_syscall())) { - table_len = ARRAY_SIZE(compat_sc_table); - if (unlikely(id < 0 || id >= table_len)) { - return; - } - entry = &compat_sc_table[id]; - dispatch_list = &event_notifier_group->event_notifier_compat_syscall_dispatch[id]; - } else { - table_len = ARRAY_SIZE(sc_table); - if (unlikely(id < 0 || id >= table_len)) { - return; - } - entry = &sc_table[id]; - dispatch_list = &event_notifier_group->event_notifier_syscall_dispatch[id]; - } - - if (unlikely(id < 0 || id >= table_len)) { - syscall_entry_event_notifier_unknown(event_notifier_group, regs, id); - return; - } - - /* TODO handle unknown syscall */ - - list_for_each_entry_rcu(iter, dispatch_list, u.syscall.node) { - BUG_ON(iter->u.syscall.syscall_id != id); - syscall_entry_call_func(entry->event_notifier_func, - entry->nrargs, iter, regs); - } -} - static void syscall_exit_event_unknown(struct lttng_event *event, struct pt_regs *regs, int id, long ret) { @@ -980,157 +918,8 @@ int lttng_syscalls_register_event(struct lttng_channel *chan, void *filter) } /* - * Should be called with sessions lock held. + * Only called at session destruction. */ -int lttng_syscalls_register_event_notifier(struct lttng_event_notifier_enabler *event_notifier_enabler, void *filter) -{ - struct lttng_event_notifier_group *group = event_notifier_enabler->group; - unsigned int i; - int ret = 0; - - wrapper_vmalloc_sync_mappings(); - - if (!group->event_notifier_syscall_dispatch) { - group->event_notifier_syscall_dispatch = kzalloc(sizeof(struct list_head) - * ARRAY_SIZE(sc_table), GFP_KERNEL); - if (!group->event_notifier_syscall_dispatch) - return -ENOMEM; - - /* Initialize all list_head */ - for (i = 0; i < ARRAY_SIZE(sc_table); i++) - INIT_LIST_HEAD(&group->event_notifier_syscall_dispatch[i]); - } - -#ifdef CONFIG_COMPAT - if (!group->event_notifier_compat_syscall_dispatch) { - group->event_notifier_compat_syscall_dispatch = kzalloc(sizeof(struct list_head) - * ARRAY_SIZE(compat_sc_table), GFP_KERNEL); - if (!group->event_notifier_syscall_dispatch) - return -ENOMEM; - - /* Initialize all list_head */ - for (i = 0; i < ARRAY_SIZE(compat_sc_table); i++) - INIT_LIST_HEAD(&group->event_notifier_compat_syscall_dispatch[i]); - } -#endif - - if (!group->sys_enter_registered) { - ret = lttng_wrapper_tracepoint_probe_register("sys_enter", - (void *) syscall_entry_event_notifier_probe, group); - if (ret) - return ret; - group->sys_enter_registered = 1; - } - - return ret; -} - -static int create_matching_event_notifiers(struct lttng_event_notifier_enabler *event_notifier_enabler, - void *filter, const struct trace_syscall_entry *table, - size_t table_len, bool is_compat) -{ - struct lttng_event_notifier_group *group = event_notifier_enabler->group; - const struct lttng_event_desc *desc; - uint64_t user_token = event_notifier_enabler->base.user_token; - unsigned int i; - int ret = 0; - - /* iterate over all syscall and create event_notifier that match */ - for (i = 0; i < table_len; i++) { - struct lttng_event_notifier *event_notifier; - struct lttng_kernel_event_notifier event_notifier_param; - struct hlist_head *head; - int found = 0; - - desc = table[i].desc; - if (!desc) { - /* Unknown syscall */ - continue; - } - - if (!lttng_desc_match_enabler(desc, - lttng_event_notifier_enabler_as_enabler(event_notifier_enabler))) - continue; - - /* - * Check if already created. - */ - head = utils_borrow_hash_table_bucket(group->event_notifiers_ht.table, - LTTNG_EVENT_NOTIFIER_HT_SIZE, desc->name); - lttng_hlist_for_each_entry(event_notifier, head, hlist) { - if (event_notifier->desc == desc - && event_notifier->user_token == event_notifier_enabler->base.user_token) - found = 1; - } - if (found) - continue; - - memset(&event_notifier_param, 0, sizeof(event_notifier_param)); - strncat(event_notifier_param.event.name, desc->name, - LTTNG_KERNEL_SYM_NAME_LEN - strlen(event_notifier_param.event.name) - 1); - event_notifier_param.event.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; - event_notifier_param.event.instrumentation = LTTNG_KERNEL_SYSCALL; - - event_notifier = _lttng_event_notifier_create(desc, user_token, group, - &event_notifier_param, filter, - event_notifier_param.event.instrumentation); - if (IS_ERR(event_notifier)) { - printk(KERN_INFO "Unable to create event_notifier %s\n", - desc->name); - ret = -ENOMEM; - goto end; - } - - event_notifier->u.syscall.syscall_id = i; - event_notifier->u.syscall.is_compat = is_compat; - } -end: - return ret; - -} - -int lttng_syscals_create_matching_event_notifiers(struct lttng_event_notifier_enabler *event_notifier_enabler, void *filter) -{ - int ret; - - ret = create_matching_event_notifiers(event_notifier_enabler, filter, sc_table, - ARRAY_SIZE(sc_table), false); - if (ret) - goto end; - - ret = create_matching_event_notifiers(event_notifier_enabler, filter, compat_sc_table, - ARRAY_SIZE(compat_sc_table), true); -end: - return ret; -} - -/* - * Unregister the syscall event_notifier probes from the callsites. - */ -int lttng_syscalls_unregister_event_notifier(struct lttng_event_notifier_group *event_notifier_group) -{ - int ret; - - /* - * Only register the event_notifier probe on the `sys_enter` callsite for now. - * At the moment, we don't think it's desirable to have one fired - * event_notifier for the entry and one for the exit of a syscall. - */ - if (event_notifier_group->sys_enter_registered) { - ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter", - (void *) syscall_entry_event_notifier_probe, event_notifier_group); - if (ret) - return ret; - event_notifier_group->sys_enter_registered = 0; - } - - kfree(event_notifier_group->event_notifier_syscall_dispatch); -#ifdef CONFIG_COMPAT - kfree(event_notifier_group->event_notifier_compat_syscall_dispatch); -#endif - return 0; -} - int lttng_syscalls_unregister_event(struct lttng_channel *chan) { int ret; @@ -1310,23 +1099,6 @@ int lttng_syscall_filter_enable_event(struct lttng_channel *chan, return 0; } -int lttng_syscall_filter_enable_event_notifier( - struct lttng_event_notifier *event_notifier) -{ - struct lttng_event_notifier_group *group = event_notifier->group; - unsigned int syscall_id = event_notifier->u.syscall.syscall_id; - struct list_head *dispatch_list; - - if (event_notifier->u.syscall.is_compat) - dispatch_list = &group->event_notifier_compat_syscall_dispatch[syscall_id]; - else - dispatch_list = &group->event_notifier_syscall_dispatch[syscall_id]; - - list_add_rcu(&event_notifier->u.syscall.node, dispatch_list); - - return 0; -} - int lttng_syscall_filter_disable_event(struct lttng_channel *chan, struct lttng_event *event) { @@ -1387,13 +1159,6 @@ int lttng_syscall_filter_disable_event(struct lttng_channel *chan, return 0; } -int lttng_syscall_filter_disable_event_notifier( - struct lttng_event_notifier *event_notifier) -{ - list_del_rcu(&event_notifier->u.syscall.node); - return 0; -} - static const struct trace_syscall_entry *syscall_list_get_entry(loff_t *pos) {