callstack context: use delimiter when stack is incomplete

[lttng-modules.git] / lttng-syscalls.c

diff --git a/lttng-syscalls.c b/lttng-syscalls.c
index 00584e3eb2ed907cbe241b42756fe345ad5fc512..0b980a1a92be53dc11442e672ff7f1ab0b08b5c6 100644 (file)
--- a/lttng-syscalls.c
+++ b/lttng-syscalls.c
@@ -29,12 +29,16 @@
 #include <linux/in6.h>
 #include <linux/seq_file.h>
 #include <linux/stringify.h>
+#include <linux/file.h>
+#include <linux/anon_inodes.h>
 #include <asm/ptrace.h>
 #include <asm/syscall.h>
 
-#include "lib/bitfield.h"
-#include "wrapper/tracepoint.h"
-#include "lttng-events.h"
+#include <lib/bitfield.h>
+#include <wrapper/tracepoint.h>
+#include <wrapper/file.h>
+#include <wrapper/rcu.h>
+#include <lttng-events.h>
 
 #ifndef CONFIG_COMPAT
 # ifndef is_compat_task
@@ -42,6 +46,11 @@
 # endif
 #endif
 
+/* in_compat_syscall appears in kernel 4.6. */
+#ifndef in_compat_syscall
+ #define in_compat_syscall()   is_compat_task()
+#endif
+
 enum sc_type {
        SC_TYPE_ENTRY,
        SC_TYPE_EXIT,
@@ -73,6 +82,8 @@ struct oldold_utsname;
 struct old_utsname;
 struct sel_arg_struct;
 struct mmap_arg_struct;
+struct file_handle;
+struct user_msghdr;
 
 #ifdef IA32_NR_syscalls
 #define NR_compat_syscalls IA32_NR_syscalls
@@ -86,13 +97,14 @@ struct mmap_arg_struct;
 #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/headers
 
 #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/headers/syscalls_unknown.h>
 #undef TRACE_SYSTEM
 
 #define SC_ENTER
@@ -109,29 +121,32 @@ struct mmap_arg_struct;
 /* Hijack probe callback for system call enter */
 #undef TP_PROBE_CB
 #define TP_PROBE_CB(_template)         &syscall_entry_probe
-#define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _struct, _assign, _printk) \
+#define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _fields) \
        LTTNG_TRACEPOINT_EVENT(syscall_entry_##_name, PARAMS(_proto), PARAMS(_args), \
-               PARAMS(_struct), PARAMS(_assign), PARAMS(_printk))
-#define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code, _struct, _assign, _printk) \
+               PARAMS(_fields))
+#define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code_pre, _fields, _code_post) \
        LTTNG_TRACEPOINT_EVENT_CODE(syscall_entry_##_name, PARAMS(_proto), PARAMS(_args), \
-               PARAMS(_locvar), PARAMS(_code),                                 \
-               PARAMS(_struct), PARAMS(_assign), PARAMS(_printk))
-#define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \
-       LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(syscall_entry_##_name, PARAMS(_struct), PARAMS(_assign), \
-               PARAMS(_printk))
+               PARAMS(_locvar), PARAMS(_code_pre),                             \
+               PARAMS(_fields), PARAMS(_code_post))
+#define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _fields) \
+       LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(syscall_entry_##_name, PARAMS(_fields))
 #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name)            \
        LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(syscall_entry_##_template, syscall_entry_##_name)
+/* Enumerations only defined at first inclusion. */
+#define SC_LTTNG_TRACEPOINT_ENUM(_name, _values) \
+       LTTNG_TRACEPOINT_ENUM(_name, PARAMS(_values))
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM syscall_entry_integers
 #define TRACE_INCLUDE_FILE syscalls_integers
-#include "instrumentation/syscalls/headers/syscalls_integers.h"
+#include <instrumentation/syscalls/headers/syscalls_integers.h>
 #undef TRACE_INCLUDE_FILE
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM syscall_entry_pointers
 #define TRACE_INCLUDE_FILE syscalls_pointers
-#include "instrumentation/syscalls/headers/syscalls_pointers.h"
+#include <instrumentation/syscalls/headers/syscalls_pointers.h>
 #undef TRACE_INCLUDE_FILE
 #undef TRACE_SYSTEM
+#undef SC_LTTNG_TRACEPOINT_ENUM
 #undef SC_LTTNG_TRACEPOINT_EVENT_CODE
 #undef SC_LTTNG_TRACEPOINT_EVENT
 #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS
@@ -142,30 +157,31 @@ struct mmap_arg_struct;
 
 /* Hijack probe callback for compat system call enter */
 #define TP_PROBE_CB(_template)         &syscall_entry_probe
-#define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _struct, _assign, _printk) \
+#define LTTNG_SC_COMPAT
+#define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _fields) \
        LTTNG_TRACEPOINT_EVENT(compat_syscall_entry_##_name, PARAMS(_proto), PARAMS(_args), \
-               PARAMS(_struct), PARAMS(_assign),                               \
-               PARAMS(_printk))
-#define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code, _struct, _assign, _printk) \
+               PARAMS(_fields))
+#define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code_pre, _fields, _code_post) \
        LTTNG_TRACEPOINT_EVENT_CODE(compat_syscall_entry_##_name, PARAMS(_proto), PARAMS(_args), \
-               PARAMS(_locvar), PARAMS(_code),                                 \
-               PARAMS(_struct), PARAMS(_assign), PARAMS(_printk))
-#define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \
-       LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(compat_syscall_entry_##_name, PARAMS(_struct), \
-               PARAMS(_assign), PARAMS(_printk))
+               PARAMS(_locvar), PARAMS(_code_pre), PARAMS(_fields), PARAMS(_code_post))
+#define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _fields) \
+       LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(compat_syscall_entry_##_name, PARAMS(_fields))
 #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name)            \
        LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(compat_syscall_entry_##_template, \
                compat_syscall_entry_##_name)
+/* Enumerations only defined at inital inclusion (not here). */
+#define SC_LTTNG_TRACEPOINT_ENUM(_name, _values)
 #define TRACE_SYSTEM compat_syscall_entry_integers
 #define TRACE_INCLUDE_FILE compat_syscalls_integers
-#include "instrumentation/syscalls/headers/compat_syscalls_integers.h"
+#include <instrumentation/syscalls/headers/compat_syscalls_integers.h>
 #undef TRACE_INCLUDE_FILE
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM compat_syscall_entry_pointers
 #define TRACE_INCLUDE_FILE compat_syscalls_pointers
-#include "instrumentation/syscalls/headers/compat_syscalls_pointers.h"
+#include <instrumentation/syscalls/headers/compat_syscalls_pointers.h>
 #undef TRACE_INCLUDE_FILE
 #undef TRACE_SYSTEM
+#undef SC_LTTNG_TRACEPOINT_ENUM
 #undef SC_LTTNG_TRACEPOINT_EVENT_CODE
 #undef SC_LTTNG_TRACEPOINT_EVENT
 #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS
@@ -173,6 +189,7 @@ struct mmap_arg_struct;
 #undef TP_PROBE_CB
 #undef _TRACE_SYSCALLS_INTEGERS_H
 #undef _TRACE_SYSCALLS_POINTERS_H
+#undef LTTNG_SC_COMPAT
 
 #undef SC_ENTER
 
@@ -189,29 +206,30 @@ struct mmap_arg_struct;
 
 /* Hijack probe callback for system call exit */
 #define TP_PROBE_CB(_template)         &syscall_exit_probe
-#define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _struct, _assign, _printk) \
+#define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _fields) \
        LTTNG_TRACEPOINT_EVENT(syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \
-               PARAMS(_struct), PARAMS(_assign), PARAMS(_printk))
-#define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code, _struct, _assign, _printk) \
+               PARAMS(_fields))
+#define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code_pre, _fields, _code_post) \
        LTTNG_TRACEPOINT_EVENT_CODE(syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \
-               PARAMS(_locvar), PARAMS(_code),                                 \
-               PARAMS(_struct), PARAMS(_assign), PARAMS(_printk))
-#define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \
-       LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(syscall_exit_##_name, PARAMS(_struct), \
-               PARAMS(_assign), PARAMS(_printk))
+               PARAMS(_locvar), PARAMS(_code_pre), PARAMS(_fields), PARAMS(_code_post))
+#define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _fields) \
+       LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(syscall_exit_##_name, PARAMS(_fields))
 #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name)            \
        LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(syscall_exit_##_template,        \
                syscall_exit_##_name)
+/* Enumerations only defined at inital inclusion (not here). */
+#define SC_LTTNG_TRACEPOINT_ENUM(_name, _values)
 #define TRACE_SYSTEM syscall_exit_integers
 #define TRACE_INCLUDE_FILE syscalls_integers
-#include "instrumentation/syscalls/headers/syscalls_integers.h"
+#include <instrumentation/syscalls/headers/syscalls_integers.h>
 #undef TRACE_INCLUDE_FILE
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM syscall_exit_pointers
 #define TRACE_INCLUDE_FILE syscalls_pointers
-#include "instrumentation/syscalls/headers/syscalls_pointers.h"
+#include <instrumentation/syscalls/headers/syscalls_pointers.h>
 #undef TRACE_INCLUDE_FILE
 #undef TRACE_SYSTEM
+#undef SC_LTTNG_TRACEPOINT_ENUM
 #undef SC_LTTNG_TRACEPOINT_EVENT_CODE
 #undef SC_LTTNG_TRACEPOINT_EVENT
 #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS
@@ -223,29 +241,31 @@ struct mmap_arg_struct;
 
 /* Hijack probe callback for compat system call exit */
 #define TP_PROBE_CB(_template)         &syscall_exit_probe
-#define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _struct, _assign, _printk) \
+#define LTTNG_SC_COMPAT
+#define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _fields) \
        LTTNG_TRACEPOINT_EVENT(compat_syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \
-               PARAMS(_struct), PARAMS(_assign), PARAMS(_printk))
-#define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code, _struct, _assign, _printk) \
+               PARAMS(_fields))
+#define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code_pre, _fields, _code_post) \
        LTTNG_TRACEPOINT_EVENT_CODE(compat_syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \
-               PARAMS(_locvar), PARAMS(_code),                                 \
-               PARAMS(_struct), PARAMS(_assign), PARAMS(_printk))
-#define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \
-       LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(compat_syscall_exit_##_name, PARAMS(_struct), \
-               PARAMS(_assign), PARAMS(_printk))
+               PARAMS(_locvar), PARAMS(_code_pre), PARAMS(_fields), PARAMS(_code_post))
+#define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _fields) \
+       LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(compat_syscall_exit_##_name, PARAMS(_fields))
 #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name)            \
        LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(compat_syscall_exit_##_template, \
                compat_syscall_exit_##_name)
+/* Enumerations only defined at inital inclusion (not here). */
+#define SC_LTTNG_TRACEPOINT_ENUM(_name, _values)
 #define TRACE_SYSTEM compat_syscall_exit_integers
 #define TRACE_INCLUDE_FILE compat_syscalls_integers
-#include "instrumentation/syscalls/headers/compat_syscalls_integers.h"
+#include <instrumentation/syscalls/headers/compat_syscalls_integers.h>
 #undef TRACE_INCLUDE_FILE
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM compat_syscall_exit_pointers
 #define TRACE_INCLUDE_FILE compat_syscalls_pointers
-#include "instrumentation/syscalls/headers/compat_syscalls_pointers.h"
+#include <instrumentation/syscalls/headers/compat_syscalls_pointers.h>
 #undef TRACE_INCLUDE_FILE
 #undef TRACE_SYSTEM
+#undef SC_LTTNG_TRACEPOINT_ENUM
 #undef SC_LTTNG_TRACEPOINT_EVENT_CODE
 #undef SC_LTTNG_TRACEPOINT_EVENT
 #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS
@@ -253,6 +273,7 @@ struct mmap_arg_struct;
 #undef TP_PROBE_CB
 #undef _TRACE_SYSCALLS_INTEGERS_H
 #undef _TRACE_SYSCALLS_POINTERS_H
+#undef LTTNG_SC_COMPAT
 
 #undef SC_EXIT
 
@@ -285,8 +306,8 @@ struct trace_syscall_entry {
 
 /* Syscall enter tracing table */
 static const struct trace_syscall_entry sc_table[] = {
-#include "instrumentation/syscalls/headers/syscalls_integers.h"
-#include "instrumentation/syscalls/headers/syscalls_pointers.h"
+#include <instrumentation/syscalls/headers/syscalls_integers.h>
+#include <instrumentation/syscalls/headers/syscalls_pointers.h>
 };
 
 #undef TRACE_SYSCALL_TABLE
@@ -300,8 +321,8 @@ static const struct trace_syscall_entry sc_table[] = {
 
 /* Compat syscall enter table */
 const struct trace_syscall_entry compat_sc_table[] = {
-#include "instrumentation/syscalls/headers/compat_syscalls_integers.h"
-#include "instrumentation/syscalls/headers/compat_syscalls_pointers.h"
+#include <instrumentation/syscalls/headers/compat_syscalls_integers.h>
+#include <instrumentation/syscalls/headers/compat_syscalls_pointers.h>
 };
 
 #undef SC_ENTER
@@ -322,8 +343,8 @@ const struct trace_syscall_entry compat_sc_table[] = {
 
 /* Syscall exit table */
 static const struct trace_syscall_entry sc_exit_table[] = {
-#include "instrumentation/syscalls/headers/syscalls_integers.h"
-#include "instrumentation/syscalls/headers/syscalls_pointers.h"
+#include <instrumentation/syscalls/headers/syscalls_integers.h>
+#include <instrumentation/syscalls/headers/syscalls_pointers.h>
 };
 
 #undef TRACE_SYSCALL_TABLE
@@ -337,8 +358,8 @@ static const struct trace_syscall_entry sc_exit_table[] = {
 
 /* Compat syscall exit table */
 const struct trace_syscall_entry compat_sc_exit_table[] = {
-#include "instrumentation/syscalls/headers/compat_syscalls_integers.h"
-#include "instrumentation/syscalls/headers/compat_syscalls_pointers.h"
+#include <instrumentation/syscalls/headers/compat_syscalls_integers.h>
+#include <instrumentation/syscalls/headers/compat_syscalls_pointers.h>
 };
 
 #undef SC_EXIT
@@ -356,7 +377,7 @@ static void syscall_entry_unknown(struct lttng_event *event,
        unsigned long args[UNKNOWN_SYSCALL_NRARGS];
 
        syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args);
-       if (unlikely(is_compat_task()))
+       if (unlikely(in_compat_syscall()))
                __event_probe__compat_syscall_entry_unknown(event, id, args);
        else
                __event_probe__syscall_entry_unknown(event, id, args);
@@ -369,12 +390,12 @@ void syscall_entry_probe(void *__data, struct pt_regs *regs, long id)
        const struct trace_syscall_entry *table, *entry;
        size_t table_len;
 
-       if (unlikely(is_compat_task())) {
+       if (unlikely(in_compat_syscall())) {
                struct lttng_syscall_filter *filter;
 
-               filter = rcu_dereference(chan->sc_filter);
+               filter = lttng_rcu_dereference(chan->sc_filter);
                if (filter) {
-                       if (id >= NR_compat_syscalls
+                       if (id < 0 || id >= NR_compat_syscalls
                                || !test_bit(id, filter->sc_compat)) {
                                /* System call filtered out. */
                                return;
@@ -386,9 +407,9 @@ void syscall_entry_probe(void *__data, struct pt_regs *regs, long id)
        } else {
                struct lttng_syscall_filter *filter;
 
-               filter = rcu_dereference(chan->sc_filter);
+               filter = lttng_rcu_dereference(chan->sc_filter);
                if (filter) {
-                       if (id >= NR_syscalls
+                       if (id < 0 || id >= NR_syscalls
                                || !test_bit(id, filter->sc)) {
                                /* System call filtered out. */
                                return;
@@ -398,11 +419,11 @@ void syscall_entry_probe(void *__data, struct pt_regs *regs, long id)
                table_len = ARRAY_SIZE(sc_table);
                unknown_event = chan->sc_unknown;
        }
-       if (unlikely(id >= table_len)) {
+       if (unlikely(id < 0 || id >= table_len)) {
                syscall_entry_unknown(unknown_event, regs, id);
                return;
        }
-       if (unlikely(is_compat_task()))
+       if (unlikely(in_compat_syscall()))
                event = chan->compat_sc_table[id];
        else
                event = chan->sc_table[id];
@@ -502,12 +523,12 @@ void syscall_entry_probe(void *__data, struct pt_regs *regs, long id)
 }
 
 static void syscall_exit_unknown(struct lttng_event *event,
-       struct pt_regs *regs, unsigned int id, long ret)
+       struct pt_regs *regs, int id, long ret)
 {
        unsigned long args[UNKNOWN_SYSCALL_NRARGS];
 
        syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args);
-       if (unlikely(is_compat_task()))
+       if (unlikely(in_compat_syscall()))
                __event_probe__compat_syscall_exit_unknown(event, id, ret,
                        args);
        else
@@ -523,12 +544,12 @@ void syscall_exit_probe(void *__data, struct pt_regs *regs, long ret)
        long id;
 
        id = syscall_get_nr(current, regs);
-       if (unlikely(is_compat_task())) {
+       if (unlikely(in_compat_syscall())) {
                struct lttng_syscall_filter *filter;
 
-               filter = rcu_dereference(chan->sc_filter);
+               filter = lttng_rcu_dereference(chan->sc_filter);
                if (filter) {
-                       if (id >= NR_compat_syscalls
+                       if (id < 0 || id >= NR_compat_syscalls
                                || !test_bit(id, filter->sc_compat)) {
                                /* System call filtered out. */
                                return;
@@ -540,9 +561,9 @@ void syscall_exit_probe(void *__data, struct pt_regs *regs, long ret)
        } else {
                struct lttng_syscall_filter *filter;
 
-               filter = rcu_dereference(chan->sc_filter);
+               filter = lttng_rcu_dereference(chan->sc_filter);
                if (filter) {
-                       if (id >= NR_syscalls
+                       if (id < 0 || id >= NR_syscalls
                                || !test_bit(id, filter->sc)) {
                                /* System call filtered out. */
                                return;
@@ -552,11 +573,11 @@ void syscall_exit_probe(void *__data, struct pt_regs *regs, long ret)
                table_len = ARRAY_SIZE(sc_exit_table);
                unknown_event = chan->sc_exit_unknown;
        }
-       if (unlikely(id >= table_len)) {
+       if (unlikely(id < 0 || id >= table_len)) {
                syscall_exit_unknown(unknown_event, regs, id, ret);
                return;
        }
-       if (unlikely(is_compat_task()))
+       if (unlikely(in_compat_syscall()))
                event = chan->compat_sc_exit_table[id];
        else
                event = chan->sc_exit_table[id];
@@ -662,7 +683,10 @@ void syscall_exit_probe(void *__data, struct pt_regs *regs, long ret)
        }
 }
 
-/* noinline to diminish caller stack size */
+/*
+ * noinline to diminish caller stack size.
+ * Should be called with sessions lock held.
+ */
 static
 int fill_table(const struct trace_syscall_entry *table, size_t table_len,
        struct lttng_event **chan_table, struct lttng_channel *chan,
@@ -711,9 +735,9 @@ int fill_table(const struct trace_syscall_entry *table, size_t table_len,
                strncat(ev.name, desc->name,
                        LTTNG_KERNEL_SYM_NAME_LEN - strlen(ev.name) - 1);
                ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
-               ev.instrumentation = LTTNG_KERNEL_NOOP;
-               chan_table[i] = lttng_event_create(chan, &ev, filter,
-                                               desc);
+               ev.instrumentation = LTTNG_KERNEL_SYSCALL;
+               chan_table[i] = _lttng_event_create(chan, &ev, filter,
+                                               desc, ev.instrumentation);
                WARN_ON_ONCE(!chan_table[i]);
                if (IS_ERR(chan_table[i])) {
                        /*
@@ -728,6 +752,9 @@ int fill_table(const struct trace_syscall_entry *table, size_t table_len,
        return 0;
 }
 
+/*
+ * Should be called with sessions lock held.
+ */
 int lttng_syscalls_register(struct lttng_channel *chan, void *filter)
 {
        struct lttng_kernel_event ev;
@@ -775,9 +802,10 @@ int lttng_syscalls_register(struct lttng_channel *chan, void *filter)
                memset(&ev, 0, sizeof(ev));
                strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
                ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
-               ev.instrumentation = LTTNG_KERNEL_NOOP;
-               chan->sc_unknown = lttng_event_create(chan, &ev, filter,
-                                                   desc);
+               ev.instrumentation = LTTNG_KERNEL_SYSCALL;
+               chan->sc_unknown = _lttng_event_create(chan, &ev, filter,
+                                               desc,
+                                               ev.instrumentation);
                WARN_ON_ONCE(!chan->sc_unknown);
                if (IS_ERR(chan->sc_unknown)) {
                        return PTR_ERR(chan->sc_unknown);
@@ -791,9 +819,10 @@ int lttng_syscalls_register(struct lttng_channel *chan, void *filter)
                memset(&ev, 0, sizeof(ev));
                strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
                ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
-               ev.instrumentation = LTTNG_KERNEL_NOOP;
-               chan->sc_compat_unknown = lttng_event_create(chan, &ev, filter,
-                                                          desc);
+               ev.instrumentation = LTTNG_KERNEL_SYSCALL;
+               chan->sc_compat_unknown = _lttng_event_create(chan, &ev, filter,
+                                               desc,
+                                               ev.instrumentation);
                WARN_ON_ONCE(!chan->sc_unknown);
                if (IS_ERR(chan->sc_compat_unknown)) {
                        return PTR_ERR(chan->sc_compat_unknown);
@@ -807,9 +836,10 @@ int lttng_syscalls_register(struct lttng_channel *chan, void *filter)
                memset(&ev, 0, sizeof(ev));
                strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
                ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
-               ev.instrumentation = LTTNG_KERNEL_NOOP;
-               chan->compat_sc_exit_unknown = lttng_event_create(chan, &ev,
-                                               filter, desc);
+               ev.instrumentation = LTTNG_KERNEL_SYSCALL;
+               chan->compat_sc_exit_unknown = _lttng_event_create(chan, &ev,
+                                               filter, desc,
+                                               ev.instrumentation);
                WARN_ON_ONCE(!chan->compat_sc_exit_unknown);
                if (IS_ERR(chan->compat_sc_exit_unknown)) {
                        return PTR_ERR(chan->compat_sc_exit_unknown);
@@ -823,9 +853,9 @@ int lttng_syscalls_register(struct lttng_channel *chan, void *filter)
                memset(&ev, 0, sizeof(ev));
                strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
                ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
-               ev.instrumentation = LTTNG_KERNEL_NOOP;
-               chan->sc_exit_unknown = lttng_event_create(chan, &ev, filter,
-                                                desc);
+               ev.instrumentation = LTTNG_KERNEL_SYSCALL;
+               chan->sc_exit_unknown = _lttng_event_create(chan, &ev, filter,
+                                               desc, ev.instrumentation);
                WARN_ON_ONCE(!chan->sc_exit_unknown);
                if (IS_ERR(chan->sc_exit_unknown)) {
                        return PTR_ERR(chan->sc_exit_unknown);
@@ -1036,6 +1066,8 @@ int lttng_syscall_filter_disable(struct lttng_channel *chan,
        WARN_ON_ONCE(!chan->sc_table);
 
        if (!chan->sc_filter) {
+               if (!chan->syscall_all)
+                       return -EEXIST;
                filter = kzalloc(sizeof(struct lttng_syscall_filter),
                                GFP_KERNEL);
                if (!filter)
@@ -1227,16 +1259,66 @@ long lttng_channel_syscall_mask(struct lttng_channel *channel,
        filter = channel->sc_filter;
 
        for (bit = 0; bit < ARRAY_SIZE(sc_table); bit++) {
-               bt_bitfield_write_be(tmp_mask, char, bit, 1,
-                       test_bit(bit, filter->sc));
+               char state;
+
+               if (channel->sc_table) {
+                       if (filter)
+                               state = test_bit(bit, filter->sc);
+                       else
+                               state = 1;
+               } else {
+                       state = 0;
+               }
+               bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
        }
        for (; bit < sc_tables_len; bit++) {
-               bt_bitfield_write_be(tmp_mask, char, bit, 1,
-                       test_bit(bit - ARRAY_SIZE(sc_table),
-                               filter->sc_compat));
+               char state;
+
+               if (channel->compat_sc_table) {
+                       if (filter)
+                               state = test_bit(bit - ARRAY_SIZE(sc_table),
+                                               filter->sc_compat);
+                       else
+                               state = 1;
+               } else {
+                       state = 0;
+               }
+               bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
        }
        if (copy_to_user(usyscall_mask->mask, tmp_mask, bitmask_len))
                ret = -EFAULT;
        kfree(tmp_mask);
        return ret;
 }
+
+int lttng_abi_syscall_list(void)
+{
+       struct file *syscall_list_file;
+       int file_fd, ret;
+
+       file_fd = lttng_get_unused_fd();
+       if (file_fd < 0) {
+               ret = file_fd;
+               goto fd_error;
+       }
+
+       syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
+                                         &lttng_syscall_list_fops,
+                                         NULL, O_RDWR);
+       if (IS_ERR(syscall_list_file)) {
+               ret = PTR_ERR(syscall_list_file);
+               goto file_error;
+       }
+       ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
+       if (ret < 0)
+               goto open_error;
+       fd_install(file_fd, syscall_list_file);
+       return file_fd;
+
+open_error:
+       fput(syscall_list_file);
+file_error:
+       put_unused_fd(file_fd);
+fd_error:
+       return ret;
+}