Rename "tsc" to "timestamp"
[lttng-modules.git] / src / lttng-syscalls.c
index 14c79bc1ccb3a200c679c1472f41d6529b797674..5ec6be5a498514375a17bd54669096fd37471709 100644 (file)
 
 #include <lttng/bitfield.h>
 #include <wrapper/tracepoint.h>
-#include <wrapper/file.h>
 #include <wrapper/rcu.h>
 #include <wrapper/syscall.h>
+#include <wrapper/limits.h>
 #include <lttng/events.h>
 #include <lttng/events-internal.h>
 #include <lttng/utils.h>
+#include <lttng/kernel-version.h>
 
 #include "lttng-syscalls.h"
 
 
 /* in_compat_syscall appears in kernel 4.6. */
 #ifndef in_compat_syscall
- #define in_compat_syscall()   is_compat_task()
+# define in_compat_syscall()   is_compat_task()
+#endif
+
+/* in_x32_syscall appears in kernel 4.7. */
+#if (LTTNG_LINUX_VERSION_CODE < LTTNG_KERNEL_VERSION(4,7,0))
+# ifdef CONFIG_X86_X32_ABI
+#  define in_x32_syscall()     is_x32_task()
+# endif
 #endif
 
 enum sc_type {
@@ -65,30 +73,6 @@ enum sc_type {
 void syscall_entry_event_probe(void *__data, struct pt_regs *regs, long id);
 void syscall_exit_event_probe(void *__data, struct pt_regs *regs, long ret);
 
-/*
- * Forward declarations for old kernels.
- */
-struct mmsghdr;
-struct rlimit64;
-struct oldold_utsname;
-struct old_utsname;
-struct sel_arg_struct;
-struct mmap_arg_struct;
-struct file_handle;
-struct user_msghdr;
-
-/*
- * Forward declaration for kernels >= 5.6
- */
-struct timex;
-struct timeval;
-struct itimerval;
-struct itimerspec;
-
-#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0))
-typedef __kernel_old_time_t time_t;
-#endif
-
 #ifdef IA32_NR_syscalls
 #define NR_compat_syscalls IA32_NR_syscalls
 #else
@@ -101,14 +85,14 @@ typedef __kernel_old_time_t time_t;
 #define LTTNG_PACKAGE_BUILD
 #define CREATE_TRACE_POINTS
 #define TP_MODULE_NOINIT
-#define TRACE_INCLUDE_PATH instrumentation/syscalls/headers
+#define TRACE_INCLUDE_PATH instrumentation/syscalls
 
 #define PARAMS(args...)        args
 
 /* Handle unknown syscalls */
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM syscalls_unknown
-#include <instrumentation/syscalls/headers/syscalls_unknown.h>
+#include <instrumentation/syscalls/syscalls_unknown.h>
 #undef TRACE_SYSTEM
 
 #undef TP_PROBE_CB
@@ -130,6 +114,15 @@ struct lttng_syscall_filter {
        DECLARE_BITMAP(sc_exit, NR_syscalls);
        DECLARE_BITMAP(sc_compat_entry, NR_compat_syscalls);
        DECLARE_BITMAP(sc_compat_exit, NR_compat_syscalls);
+
+       /*
+        * Reference counters keeping track of number of events enabled
+        * for each bit.
+        */
+       u32 sc_entry_refcount_map[NR_syscalls];
+       u32 sc_exit_refcount_map[NR_syscalls];
+       u32 sc_compat_entry_refcount_map[NR_compat_syscalls];
+       u32 sc_compat_exit_refcount_map[NR_compat_syscalls];
 };
 
 static void syscall_entry_event_unknown(struct hlist_head *unknown_action_list_head,
@@ -256,6 +249,12 @@ void syscall_entry_event_probe(void *__data, struct pt_regs *regs, long id)
        const struct trace_syscall_entry *table, *entry;
        size_t table_len;
 
+#ifdef CONFIG_X86_X32_ABI
+       if (in_x32_syscall()) {
+               /* x32 system calls are not supported. */
+               return;
+       }
+#endif
        if (unlikely(in_compat_syscall())) {
                struct lttng_syscall_filter *filter = syscall_table->sc_filter;
 
@@ -434,6 +433,12 @@ void syscall_exit_event_probe(void *__data, struct pt_regs *regs, long ret)
        size_t table_len;
        long id;
 
+#ifdef CONFIG_X86_X32_ABI
+       if (in_x32_syscall()) {
+               /* x32 system calls are not supported. */
+               return;
+       }
+#endif
        id = syscall_get_nr(current, regs);
 
        if (unlikely(in_compat_syscall())) {
@@ -526,8 +531,7 @@ struct lttng_kernel_syscall_table *get_syscall_table_from_event(struct lttng_ker
 
 static
 void lttng_syscall_event_enabler_create_event(struct lttng_event_enabler_common *syscall_event_enabler,
-               const struct lttng_kernel_event_desc *desc, struct hlist_head *dispatch_table,
-               enum sc_type type, unsigned int syscall_nr)
+               const struct lttng_kernel_event_desc *desc, enum sc_type type, unsigned int syscall_nr)
 {
        struct lttng_kernel_event_common *event;
 
@@ -575,8 +579,6 @@ void lttng_syscall_event_enabler_create_event(struct lttng_event_enabler_common
                        return;
                }
                event->priv->u.syscall.syscall_id = syscall_nr;
-               if (dispatch_table)
-                       hlist_add_head_rcu(&event->priv->u.syscall.node, dispatch_table);
                break;
        }
        case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
@@ -625,8 +627,6 @@ void lttng_syscall_event_enabler_create_event(struct lttng_event_enabler_common
                        return;
                }
                event->priv->u.syscall.syscall_id = syscall_nr;
-               if (dispatch_table)
-                       hlist_add_head_rcu(&event->priv->u.syscall.node, dispatch_table);
                break;
        }
        default:
@@ -642,9 +642,10 @@ void lttng_syscall_event_enabler_create_matching_syscall_table_events(struct ltt
        const struct lttng_kernel_event_desc *desc;
        unsigned int i;
 
-       if (!IS_ENABLED(CONFIG_COMPAT) && (type == SC_TYPE_COMPAT_ENTRY || type == SC_TYPE_COMPAT_EXIT))
+#ifndef CONFIG_COMPAT
+       if (type == SC_TYPE_COMPAT_ENTRY || type == SC_TYPE_COMPAT_EXIT)
                return;
-
+#endif
        /* iterate over all syscall and create event that match */
        for (i = 0; i < table_len; i++) {
                struct lttng_kernel_event_common_private *event_priv;
@@ -673,7 +674,7 @@ void lttng_syscall_event_enabler_create_matching_syscall_table_events(struct ltt
                if (found)
                        continue;
 
-               lttng_syscall_event_enabler_create_event(syscall_event_enabler_common, desc, NULL, type, i);
+               lttng_syscall_event_enabler_create_event(syscall_event_enabler_common, desc, type, i);
        }
 }
 
@@ -694,17 +695,16 @@ bool lttng_syscall_event_enabler_is_wildcard_all(struct lttng_event_enabler_comm
 static
 void create_unknown_syscall_event(struct lttng_event_enabler_common *event_enabler, enum sc_type type)
 {
-       struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(event_enabler);
        struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(event_enabler);
        struct lttng_kernel_event_common_private *event_priv;
        const struct lttng_kernel_event_desc *desc;
-       struct hlist_head *unknown_dispatch_list;
        bool found = false;
        struct hlist_head *head;
 
-       if (!IS_ENABLED(CONFIG_COMPAT) && (type == SC_TYPE_COMPAT_ENTRY || type == SC_TYPE_COMPAT_EXIT))
+#ifndef CONFIG_COMPAT
+       if (type == SC_TYPE_COMPAT_ENTRY || type == SC_TYPE_COMPAT_EXIT)
                return;
-
+#endif
        /*
         * Considering that currently system calls can only be enabled on a per
         * name basis (or wildcard based on a name), unknown syscall events are
@@ -720,19 +720,15 @@ void create_unknown_syscall_event(struct lttng_event_enabler_common *event_enabl
        switch (type) {
        case SC_TYPE_ENTRY:
                desc = &__event_desc___syscall_entry_unknown;
-               unknown_dispatch_list = &syscall_table->unknown_syscall_dispatch;
                break;
        case SC_TYPE_EXIT:
                desc = &__event_desc___syscall_exit_unknown;
-               unknown_dispatch_list = &syscall_table->unknown_syscall_exit_dispatch;
                break;
        case SC_TYPE_COMPAT_ENTRY:
                desc = &__event_desc___compat_syscall_entry_unknown;
-               unknown_dispatch_list = &syscall_table->compat_unknown_syscall_dispatch;
                break;
        case SC_TYPE_COMPAT_EXIT:
                desc = &__event_desc___compat_syscall_exit_unknown;
-               unknown_dispatch_list = &syscall_table->compat_unknown_syscall_exit_dispatch;
                break;
        default:
                WARN_ON_ONCE(1);
@@ -749,7 +745,7 @@ void create_unknown_syscall_event(struct lttng_event_enabler_common *event_enabl
                }
        }
        if (!found)
-               lttng_syscall_event_enabler_create_event(event_enabler, desc, unknown_dispatch_list, type, -1U);
+               lttng_syscall_event_enabler_create_event(event_enabler, desc, type, -1U);
 }
 
 static
@@ -820,17 +816,17 @@ int lttng_event_enabler_create_syscall_events_if_missing(struct lttng_event_enab
        }
 
        if (!syscall_table->sys_enter_registered) {
-               ret = lttng_wrapper_tracepoint_probe_register("sys_enter",
+               ret = lttng_tracepoint_probe_register("sys_enter",
                                (void *) syscall_entry_event_probe, syscall_table);
                if (ret)
                        return ret;
                syscall_table->sys_enter_registered = 1;
        }
        if (!syscall_table->sys_exit_registered) {
-               ret = lttng_wrapper_tracepoint_probe_register("sys_exit",
+               ret = lttng_tracepoint_probe_register("sys_exit",
                                (void *) syscall_exit_event_probe, syscall_table);
                if (ret) {
-                       WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter",
+                       WARN_ON_ONCE(lttng_tracepoint_probe_unregister("sys_enter",
                                (void *) syscall_entry_event_probe, syscall_table));
                        return ret;
                }
@@ -839,7 +835,7 @@ int lttng_event_enabler_create_syscall_events_if_missing(struct lttng_event_enab
 
        lttng_syscall_event_enabler_create_matching_events(syscall_event_enabler);
 
-       return ret;
+       return 0;
 }
 
 int lttng_syscalls_unregister_syscall_table(struct lttng_kernel_syscall_table *syscall_table)
@@ -849,14 +845,14 @@ int lttng_syscalls_unregister_syscall_table(struct lttng_kernel_syscall_table *s
        if (!syscall_table->syscall_dispatch)
                return 0;
        if (syscall_table->sys_enter_registered) {
-               ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter",
+               ret = lttng_tracepoint_probe_unregister("sys_enter",
                                (void *) syscall_entry_event_probe, syscall_table);
                if (ret)
                        return ret;
                syscall_table->sys_enter_registered = 0;
        }
        if (syscall_table->sys_exit_registered) {
-               ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit",
+               ret = lttng_tracepoint_probe_unregister("sys_exit",
                                (void *) syscall_exit_event_probe, syscall_table);
                if (ret)
                        return ret;
@@ -877,52 +873,6 @@ int lttng_syscalls_destroy_syscall_table(struct lttng_kernel_syscall_table *sysc
        return 0;
 }
 
-static
-int get_syscall_nr(const char *syscall_name)
-{
-       int syscall_nr = -1;
-       int i;
-
-       for (i = 0; i < sc_table.len; i++) {
-               const struct trace_syscall_entry *entry;
-               const char *it_name;
-
-               entry = &sc_table.table[i];
-               if (!entry->desc)
-                       continue;
-               it_name = entry->desc->event_name;
-               it_name += strlen(SYSCALL_ENTRY_STR);
-               if (!strcmp(syscall_name, it_name)) {
-                       syscall_nr = i;
-                       break;
-               }
-       }
-       return syscall_nr;
-}
-
-static
-int get_compat_syscall_nr(const char *syscall_name)
-{
-       int syscall_nr = -1;
-       int i;
-
-       for (i = 0; i < compat_sc_table.len; i++) {
-               const struct trace_syscall_entry *entry;
-               const char *it_name;
-
-               entry = &compat_sc_table.table[i];
-               if (!entry->desc)
-                       continue;
-               it_name = entry->desc->event_name;
-               it_name += strlen(COMPAT_SYSCALL_ENTRY_STR);
-               if (!strcmp(syscall_name, it_name)) {
-                       syscall_nr = i;
-                       break;
-               }
-       }
-       return syscall_nr;
-}
-
 static
 uint32_t get_sc_tables_len(void)
 {
@@ -967,35 +917,25 @@ static
 int lttng_syscall_filter_enable(
                struct lttng_syscall_filter *filter,
                const char *desc_name, enum lttng_syscall_abi abi,
-               enum lttng_syscall_entryexit entryexit)
+               enum lttng_syscall_entryexit entryexit,
+               unsigned int syscall_id)
 {
        const char *syscall_name;
        unsigned long *bitmap;
-       int syscall_nr;
+       u32 *refcount_map;
 
        syscall_name = get_syscall_name(desc_name, abi, entryexit);
 
-       switch (abi) {
-       case LTTNG_SYSCALL_ABI_NATIVE:
-               syscall_nr = get_syscall_nr(syscall_name);
-               break;
-       case LTTNG_SYSCALL_ABI_COMPAT:
-               syscall_nr = get_compat_syscall_nr(syscall_name);
-               break;
-       default:
-               return -EINVAL;
-       }
-       if (syscall_nr < 0)
-               return -ENOENT;
-
        switch (entryexit) {
        case LTTNG_SYSCALL_ENTRY:
                switch (abi) {
                case LTTNG_SYSCALL_ABI_NATIVE:
                        bitmap = filter->sc_entry;
+                       refcount_map = filter->sc_entry_refcount_map;
                        break;
                case LTTNG_SYSCALL_ABI_COMPAT:
                        bitmap = filter->sc_compat_entry;
+                       refcount_map = filter->sc_compat_entry_refcount_map;
                        break;
                default:
                        return -EINVAL;
@@ -1005,9 +945,11 @@ int lttng_syscall_filter_enable(
                switch (abi) {
                case LTTNG_SYSCALL_ABI_NATIVE:
                        bitmap = filter->sc_exit;
+                       refcount_map = filter->sc_exit_refcount_map;
                        break;
                case LTTNG_SYSCALL_ABI_COMPAT:
                        bitmap = filter->sc_compat_exit;
+                       refcount_map = filter->sc_compat_exit_refcount_map;
                        break;
                default:
                        return -EINVAL;
@@ -1016,9 +958,10 @@ int lttng_syscall_filter_enable(
        default:
                return -EINVAL;
        }
-       if (test_bit(syscall_nr, bitmap))
-               return -EEXIST;
-       bitmap_set(bitmap, syscall_nr, 1);
+       if (refcount_map[syscall_id] == U32_MAX)
+               return -EOVERFLOW;
+       if (refcount_map[syscall_id]++ == 0)
+               bitmap_set(bitmap, syscall_id, 1);
        return 0;
 }
 
@@ -1027,46 +970,81 @@ int lttng_syscall_filter_enable_event(struct lttng_kernel_event_common *event)
        struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
        unsigned int syscall_id = event->priv->u.syscall.syscall_id;
        struct hlist_head *dispatch_list;
-       int ret;
+       int ret = 0;
 
        WARN_ON_ONCE(event->priv->instrumentation != LTTNG_KERNEL_ABI_SYSCALL);
 
-       ret = lttng_syscall_filter_enable(syscall_table->sc_filter,
-               event->priv->desc->event_name, event->priv->u.syscall.abi,
-               event->priv->u.syscall.entryexit);
-       if (ret)
-               return ret;
-
-       switch (event->priv->u.syscall.entryexit) {
-       case LTTNG_SYSCALL_ENTRY:
-               switch (event->priv->u.syscall.abi) {
-               case LTTNG_SYSCALL_ABI_NATIVE:
-                       dispatch_list = &syscall_table->syscall_dispatch[syscall_id];
+       /* Unknown syscall */
+       if (syscall_id == -1U) {
+               switch (event->priv->u.syscall.entryexit) {
+               case LTTNG_SYSCALL_ENTRY:
+                       switch (event->priv->u.syscall.abi) {
+                       case LTTNG_SYSCALL_ABI_NATIVE:
+                               dispatch_list = &syscall_table->unknown_syscall_dispatch;
+                               break;
+                       case LTTNG_SYSCALL_ABI_COMPAT:
+                               dispatch_list = &syscall_table->compat_unknown_syscall_dispatch;
+                               break;
+                       default:
+                               ret = -EINVAL;
+                               goto end;
+                       }
                        break;
-               case LTTNG_SYSCALL_ABI_COMPAT:
-                       dispatch_list = &syscall_table->compat_syscall_dispatch[syscall_id];
+               case LTTNG_SYSCALL_EXIT:
+                       switch (event->priv->u.syscall.abi) {
+                       case LTTNG_SYSCALL_ABI_NATIVE:
+                               dispatch_list = &syscall_table->unknown_syscall_exit_dispatch;
+                               break;
+                       case LTTNG_SYSCALL_ABI_COMPAT:
+                               dispatch_list = &syscall_table->compat_unknown_syscall_exit_dispatch;
+                               break;
+                       default:
+                               ret = -EINVAL;
+                               goto end;
+                       }
                        break;
                default:
                        ret = -EINVAL;
                        goto end;
                }
-               break;
-       case LTTNG_SYSCALL_EXIT:
-               switch (event->priv->u.syscall.abi) {
-               case LTTNG_SYSCALL_ABI_NATIVE:
-                       dispatch_list = &syscall_table->syscall_exit_dispatch[syscall_id];
+       } else {
+               ret = lttng_syscall_filter_enable(syscall_table->sc_filter,
+                       event->priv->desc->event_name, event->priv->u.syscall.abi,
+                       event->priv->u.syscall.entryexit, syscall_id);
+               if (ret)
+                       return ret;
+
+               switch (event->priv->u.syscall.entryexit) {
+               case LTTNG_SYSCALL_ENTRY:
+                       switch (event->priv->u.syscall.abi) {
+                       case LTTNG_SYSCALL_ABI_NATIVE:
+                               dispatch_list = &syscall_table->syscall_dispatch[syscall_id];
+                               break;
+                       case LTTNG_SYSCALL_ABI_COMPAT:
+                               dispatch_list = &syscall_table->compat_syscall_dispatch[syscall_id];
+                               break;
+                       default:
+                               ret = -EINVAL;
+                               goto end;
+                       }
                        break;
-               case LTTNG_SYSCALL_ABI_COMPAT:
-                       dispatch_list = &syscall_table->compat_syscall_exit_dispatch[syscall_id];
+               case LTTNG_SYSCALL_EXIT:
+                       switch (event->priv->u.syscall.abi) {
+                       case LTTNG_SYSCALL_ABI_NATIVE:
+                               dispatch_list = &syscall_table->syscall_exit_dispatch[syscall_id];
+                               break;
+                       case LTTNG_SYSCALL_ABI_COMPAT:
+                               dispatch_list = &syscall_table->compat_syscall_exit_dispatch[syscall_id];
+                               break;
+                       default:
+                               ret = -EINVAL;
+                               goto end;
+                       }
                        break;
                default:
                        ret = -EINVAL;
                        goto end;
                }
-               break;
-       default:
-               ret = -EINVAL;
-               goto end;
        }
 
        hlist_add_head_rcu(&event->priv->u.syscall.node, dispatch_list);
@@ -1077,35 +1055,25 @@ end:
 static
 int lttng_syscall_filter_disable(struct lttng_syscall_filter *filter,
                const char *desc_name, enum lttng_syscall_abi abi,
-               enum lttng_syscall_entryexit entryexit)
+               enum lttng_syscall_entryexit entryexit,
+               unsigned int syscall_id)
 {
        const char *syscall_name;
        unsigned long *bitmap;
-       int syscall_nr;
+       u32 *refcount_map;
 
        syscall_name = get_syscall_name(desc_name, abi, entryexit);
 
-       switch (abi) {
-       case LTTNG_SYSCALL_ABI_NATIVE:
-               syscall_nr = get_syscall_nr(syscall_name);
-               break;
-       case LTTNG_SYSCALL_ABI_COMPAT:
-               syscall_nr = get_compat_syscall_nr(syscall_name);
-               break;
-       default:
-               return -EINVAL;
-       }
-       if (syscall_nr < 0)
-               return -ENOENT;
-
        switch (entryexit) {
        case LTTNG_SYSCALL_ENTRY:
                switch (abi) {
                case LTTNG_SYSCALL_ABI_NATIVE:
                        bitmap = filter->sc_entry;
+                       refcount_map = filter->sc_entry_refcount_map;
                        break;
                case LTTNG_SYSCALL_ABI_COMPAT:
                        bitmap = filter->sc_compat_entry;
+                       refcount_map = filter->sc_compat_entry_refcount_map;
                        break;
                default:
                        return -EINVAL;
@@ -1115,9 +1083,11 @@ int lttng_syscall_filter_disable(struct lttng_syscall_filter *filter,
                switch (abi) {
                case LTTNG_SYSCALL_ABI_NATIVE:
                        bitmap = filter->sc_exit;
+                       refcount_map = filter->sc_exit_refcount_map;
                        break;
                case LTTNG_SYSCALL_ABI_COMPAT:
                        bitmap = filter->sc_compat_exit;
+                       refcount_map = filter->sc_compat_exit_refcount_map;
                        break;
                default:
                        return -EINVAL;
@@ -1126,23 +1096,27 @@ int lttng_syscall_filter_disable(struct lttng_syscall_filter *filter,
        default:
                return -EINVAL;
        }
-       if (!test_bit(syscall_nr, bitmap))
-               return -EEXIST;
-       bitmap_clear(bitmap, syscall_nr, 1);
-
+       if (refcount_map[syscall_id] == 0)
+               return -ENOENT;
+       if (--refcount_map[syscall_id] == 0)
+               bitmap_clear(bitmap, syscall_id, 1);
        return 0;
 }
 
 int lttng_syscall_filter_disable_event(struct lttng_kernel_event_common *event)
 {
        struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
+       unsigned int syscall_id = event->priv->u.syscall.syscall_id;
        int ret;
 
-       ret = lttng_syscall_filter_disable(syscall_table->sc_filter,
-               event->priv->desc->event_name, event->priv->u.syscall.abi,
-               event->priv->u.syscall.entryexit);
-       if (ret)
-               return ret;
+       /* Except for unknown syscall */
+       if (syscall_id != -1U) {
+               ret = lttng_syscall_filter_disable(syscall_table->sc_filter,
+                       event->priv->desc->event_name, event->priv->u.syscall.abi,
+                       event->priv->u.syscall.entryexit, syscall_id);
+               if (ret)
+                       return ret;
+       }
        hlist_del_rcu(&event->priv->u.syscall.node);
        return 0;
 }
@@ -1342,7 +1316,7 @@ int lttng_abi_syscall_list(void)
        struct file *syscall_list_file;
        int file_fd, ret;
 
-       file_fd = lttng_get_unused_fd();
+       file_fd = get_unused_fd_flags(0);
        if (file_fd < 0) {
                ret = file_fd;
                goto fd_error;
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