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lttng-syscalls.c
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lttng-syscalls.c
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/*
* lttng-syscalls.c
*
* LTTng syscall probes.
*
* Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; only
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/compat.h>
#include <linux/err.h>
#include <linux/bitmap.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/seq_file.h>
#include <linux/stringify.h>
#include <linux/file.h>
#include <linux/anon_inodes.h>
#include <linux/random.h>
#include <asm/ptrace.h>
#include <asm/syscall.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
# define is_compat_task() (0)
# 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,
SC_TYPE_COMPAT_ENTRY,
SC_TYPE_COMPAT_EXIT,
};
#define SYSCALL_ENTRY_TOK syscall_entry_
#define COMPAT_SYSCALL_ENTRY_TOK compat_syscall_entry_
#define SYSCALL_EXIT_TOK syscall_exit_
#define COMPAT_SYSCALL_EXIT_TOK compat_syscall_exit_
#define SYSCALL_ENTRY_STR __stringify(SYSCALL_ENTRY_TOK)
#define COMPAT_SYSCALL_ENTRY_STR __stringify(COMPAT_SYSCALL_ENTRY_TOK)
#define SYSCALL_EXIT_STR __stringify(SYSCALL_EXIT_TOK)
#define COMPAT_SYSCALL_EXIT_STR __stringify(COMPAT_SYSCALL_EXIT_TOK)
static
void syscall_entry_probe(void *__data, struct pt_regs *regs, long id);
static
void syscall_exit_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;
#ifdef IA32_NR_syscalls
#define NR_compat_syscalls IA32_NR_syscalls
#else
#define NR_compat_syscalls NR_syscalls
#endif
/*
* Create LTTng tracepoint probes.
*/
#define LTTNG_PACKAGE_BUILD
#define CREATE_TRACE_POINTS
#define TP_MODULE_NOINIT
#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>
#undef TRACE_SYSTEM
#define SC_ENTER
#undef sc_exit
#define sc_exit(...)
#undef sc_in
#define sc_in(...) __VA_ARGS__
#undef sc_out
#define sc_out(...)
#undef sc_inout
#define sc_inout(...) __VA_ARGS__
/* 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, _fields) \
LTTNG_TRACEPOINT_EVENT(syscall_entry_##_name, PARAMS(_proto), PARAMS(_args), \
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_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>
#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>
#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
#undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS
#undef TP_PROBE_CB
#undef _TRACE_SYSCALLS_INTEGERS_H
#undef _TRACE_SYSCALLS_POINTERS_H
/* Hijack probe callback for compat system call enter */
#define TP_PROBE_CB(_template) &syscall_entry_probe
#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(_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_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>
#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>
#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
#undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS
#undef TP_PROBE_CB
#undef _TRACE_SYSCALLS_INTEGERS_H
#undef _TRACE_SYSCALLS_POINTERS_H
#undef LTTNG_SC_COMPAT
#undef SC_ENTER
#define SC_EXIT
#undef sc_exit
#define sc_exit(...) __VA_ARGS__
#undef sc_in
#define sc_in(...)
#undef sc_out
#define sc_out(...) __VA_ARGS__
#undef sc_inout
#define sc_inout(...) __VA_ARGS__
/* Hijack probe callback for system call exit */
#define TP_PROBE_CB(_template) &syscall_exit_probe
#define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _fields) \
LTTNG_TRACEPOINT_EVENT(syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \
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_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>
#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>
#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
#undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS
#undef TP_PROBE_CB
#undef _TRACE_SYSCALLS_INTEGERS_H
#undef _TRACE_SYSCALLS_POINTERS_H
/* Hijack probe callback for compat system call exit */
#define TP_PROBE_CB(_template) &syscall_exit_probe
#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(_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_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>
#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>
#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
#undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS
#undef TP_PROBE_CB
#undef _TRACE_SYSCALLS_INTEGERS_H
#undef _TRACE_SYSCALLS_POINTERS_H
#undef LTTNG_SC_COMPAT
#undef SC_EXIT
#undef TP_MODULE_NOINIT
#undef LTTNG_PACKAGE_BUILD
#undef CREATE_TRACE_POINTS
struct trace_syscall_entry {
void *func;
const struct lttng_event_desc *desc;
const struct lttng_event_field *fields;
unsigned int nrargs;
};
#define CREATE_SYSCALL_TABLE
#define SC_ENTER
#undef sc_exit
#define sc_exit(...)
#undef TRACE_SYSCALL_TABLE
#define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
[ _nr ] = { \
.func = __event_probe__syscall_entry_##_template, \
.nrargs = (_nrargs), \
.fields = __event_fields___syscall_entry_##_template, \
.desc = &__event_desc___syscall_entry_##_name, \
},
/* 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>
};
#undef TRACE_SYSCALL_TABLE
#define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
[ _nr ] = { \
.func = __event_probe__compat_syscall_entry_##_template, \
.nrargs = (_nrargs), \
.fields = __event_fields___compat_syscall_entry_##_template, \
.desc = &__event_desc___compat_syscall_entry_##_name, \
},
/* 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>
};
#undef SC_ENTER
#define SC_EXIT
#undef sc_exit
#define sc_exit(...) __VA_ARGS__
#undef TRACE_SYSCALL_TABLE
#define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
[ _nr ] = { \
.func = __event_probe__syscall_exit_##_template, \
.nrargs = (_nrargs), \
.fields = __event_fields___syscall_exit_##_template, \
.desc = &__event_desc___syscall_exit_##_name, \
},
/* 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>
};
#undef TRACE_SYSCALL_TABLE
#define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
[ _nr ] = { \
.func = __event_probe__compat_syscall_exit_##_template, \
.nrargs = (_nrargs), \
.fields = __event_fields___compat_syscall_exit_##_template, \
.desc = &__event_desc___compat_syscall_exit_##_name, \
},
/* 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>
};
#undef SC_EXIT
#undef CREATE_SYSCALL_TABLE
struct lttng_syscall_filter {
DECLARE_BITMAP(sc, NR_syscalls);
DECLARE_BITMAP(sc_compat, NR_compat_syscalls);
};
static void syscall_entry_unknown(struct lttng_event *event,
struct pt_regs *regs, unsigned int id)
{
unsigned long args[UNKNOWN_SYSCALL_NRARGS];
syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args);
if (unlikely(in_compat_syscall()))
__event_probe__compat_syscall_entry_unknown(event, id, args);
else
__event_probe__syscall_entry_unknown(event, id, args);
}
void syscall_entry_probe(void *__data, struct pt_regs *regs, long id)
{
struct lttng_channel *chan = __data;
struct lttng_event *event, *unknown_event;
const struct trace_syscall_entry *table, *entry;
size_t table_len;
// jaeger syscall_entry
if (current->jaeger_trace_id) {
// generate random uint64_t
uint64_t span = ((uint64_t)get_random_int()) << 32 | (uint64_t)get_random_int();
current->jaeger_span_id = span;
} else {
// drop traces without jaeger information
current->jaeger_parent_id = 0;
current->jaeger_span_id = 0;
return;
}
if (unlikely(in_compat_syscall())) {
struct lttng_syscall_filter *filter;
filter = lttng_rcu_dereference(chan->sc_filter);
if (filter) {
if (id < 0 || id >= NR_compat_syscalls
|| !test_bit(id, filter->sc_compat)) {
/* System call filtered out. */
return;
}
}
table = compat_sc_table;
table_len = ARRAY_SIZE(compat_sc_table);
unknown_event = chan->sc_compat_unknown;
} else {
struct lttng_syscall_filter *filter;
filter = lttng_rcu_dereference(chan->sc_filter);
if (filter) {
if (id < 0 || id >= NR_syscalls
|| !test_bit(id, filter->sc)) {
/* System call filtered out. */
return;
}
}
table = sc_table;
table_len = ARRAY_SIZE(sc_table);
unknown_event = chan->sc_unknown;
}
if (unlikely(id < 0 || id >= table_len)) {
syscall_entry_unknown(unknown_event, regs, id);
return;
}
if (unlikely(in_compat_syscall()))
event = chan->compat_sc_table[id];
else
event = chan->sc_table[id];
if (unlikely(!event)) {
syscall_entry_unknown(unknown_event, regs, id);
return;
}
entry = &table[id];
WARN_ON_ONCE(!entry);
switch (entry->nrargs) {
case 0:
{
void (*fptr)(void *__data) = entry->func;
fptr(event);
break;
}
case 1:
{
void (*fptr)(void *__data, unsigned long arg0) = entry->func;
unsigned long args[1];
syscall_get_arguments(current, regs, 0, entry->nrargs, args);
fptr(event, args[0]);
break;
}
case 2:
{
void (*fptr)(void *__data,
unsigned long arg0,
unsigned long arg1) = entry->func;
unsigned long args[2];
syscall_get_arguments(current, regs, 0, entry->nrargs, args);
fptr(event, args[0], args[1]);
break;
}
case 3:
{
void (*fptr)(void *__data,
unsigned long arg0,
unsigned long arg1,
unsigned long arg2) = entry->func;
unsigned long args[3];
syscall_get_arguments(current, regs, 0, entry->nrargs, args);
fptr(event, args[0], args[1], args[2]);
break;
}
case 4:
{
void (*fptr)(void *__data,
unsigned long arg0,
unsigned long arg1,
unsigned long arg2,
unsigned long arg3) = entry->func;
unsigned long args[4];
syscall_get_arguments(current, regs, 0, entry->nrargs, args);
fptr(event, args[0], args[1], args[2], args[3]);
break;
}
case 5:
{
void (*fptr)(void *__data,
unsigned long arg0,
unsigned long arg1,
unsigned long arg2,
unsigned long arg3,
unsigned long arg4) = entry->func;
unsigned long args[5];
syscall_get_arguments(current, regs, 0, entry->nrargs, args);
fptr(event, args[0], args[1], args[2], args[3], args[4]);
break;
}
case 6:
{
void (*fptr)(void *__data,
unsigned long arg0,
unsigned long arg1,
unsigned long arg2,
unsigned long arg3,
unsigned long arg4,
unsigned long arg5) = entry->func;
unsigned long args[6];
syscall_get_arguments(current, regs, 0, entry->nrargs, args);
fptr(event, args[0], args[1], args[2],
args[3], args[4], args[5]);
break;
}
default:
break;
}
}
static void syscall_exit_unknown(struct lttng_event *event,
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(in_compat_syscall()))
__event_probe__compat_syscall_exit_unknown(event, id, ret,
args);
else
__event_probe__syscall_exit_unknown(event, id, ret, args);
}
void syscall_exit_probe(void *__data, struct pt_regs *regs, long ret)
{
struct lttng_channel *chan = __data;
struct lttng_event *event, *unknown_event;
const struct trace_syscall_entry *table, *entry;
size_t table_len;
long id;
// jaeger syscall_exit
if (!current->jaeger_trace_id) {
// drop traces without jaeger information
current->jaeger_parent_id = 0;
current->jaeger_span_id = 0;
return;
}
id = syscall_get_nr(current, regs);
if (unlikely(in_compat_syscall())) {
struct lttng_syscall_filter *filter;
filter = lttng_rcu_dereference(chan->sc_filter);
if (filter) {
if (id < 0 || id >= NR_compat_syscalls
|| !test_bit(id, filter->sc_compat)) {
/* System call filtered out. */
return;
}
}
table = compat_sc_exit_table;
table_len = ARRAY_SIZE(compat_sc_exit_table);
unknown_event = chan->compat_sc_exit_unknown;
} else {
struct lttng_syscall_filter *filter;
filter = lttng_rcu_dereference(chan->sc_filter);
if (filter) {
if (id < 0 || id >= NR_syscalls
|| !test_bit(id, filter->sc)) {
/* System call filtered out. */
return;
}
}
table = sc_exit_table;
table_len = ARRAY_SIZE(sc_exit_table);
unknown_event = chan->sc_exit_unknown;
}
if (unlikely(id < 0 || id >= table_len)) {
syscall_exit_unknown(unknown_event, regs, id, ret);
return;
}
if (unlikely(in_compat_syscall()))
event = chan->compat_sc_exit_table[id];
else
event = chan->sc_exit_table[id];
if (unlikely(!event)) {
syscall_exit_unknown(unknown_event, regs, id, ret);
return;
}
entry = &table[id];
WARN_ON_ONCE(!entry);
switch (entry->nrargs) {
case 0:
{
void (*fptr)(void *__data, long ret) = entry->func;
fptr(event, ret);
break;
}
case 1:
{
void (*fptr)(void *__data,
long ret,
unsigned long arg0) = entry->func;
unsigned long args[1];
syscall_get_arguments(current, regs, 0, entry->nrargs, args);
fptr(event, ret, args[0]);
break;
}
case 2:
{
void (*fptr)(void *__data,
long ret,
unsigned long arg0,
unsigned long arg1) = entry->func;
unsigned long args[2];
syscall_get_arguments(current, regs, 0, entry->nrargs, args);
fptr(event, ret, args[0], args[1]);
break;
}
case 3:
{
void (*fptr)(void *__data,
long ret,
unsigned long arg0,
unsigned long arg1,
unsigned long arg2) = entry->func;
unsigned long args[3];
syscall_get_arguments(current, regs, 0, entry->nrargs, args);
fptr(event, ret, args[0], args[1], args[2]);
break;
}
case 4:
{
void (*fptr)(void *__data,
long ret,
unsigned long arg0,
unsigned long arg1,
unsigned long arg2,
unsigned long arg3) = entry->func;
unsigned long args[4];
syscall_get_arguments(current, regs, 0, entry->nrargs, args);
fptr(event, ret, args[0], args[1], args[2], args[3]);
break;
}
case 5:
{
void (*fptr)(void *__data,
long ret,
unsigned long arg0,
unsigned long arg1,
unsigned long arg2,
unsigned long arg3,
unsigned long arg4) = entry->func;
unsigned long args[5];
syscall_get_arguments(current, regs, 0, entry->nrargs, args);
fptr(event, ret, args[0], args[1], args[2], args[3], args[4]);
break;
}
case 6:
{
void (*fptr)(void *__data,
long ret,
unsigned long arg0,
unsigned long arg1,
unsigned long arg2,
unsigned long arg3,
unsigned long arg4,
unsigned long arg5) = entry->func;
unsigned long args[6];
syscall_get_arguments(current, regs, 0, entry->nrargs, args);
fptr(event, ret, args[0], args[1], args[2],
args[3], args[4], args[5]);
break;
}
default:
break;
}
// jaeger syscall_exit
if (current->jaeger_trace_id || current->jaeger_span_id) {
current->jaeger_span_id = 0;
}
}
/*
* 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,
void *filter, enum sc_type type)
{
const struct lttng_event_desc *desc;
unsigned int i;
/* Allocate events for each syscall, insert into table */
for (i = 0; i < table_len; i++) {
struct lttng_kernel_event ev;
desc = table[i].desc;
if (!desc) {
/* Unknown syscall */
continue;
}
/*
* Skip those already populated by previous failed
* register for this channel.
*/
if (chan_table[i])
continue;
memset(&ev, 0, sizeof(ev));
switch (type) {
case SC_TYPE_ENTRY:
strncpy(ev.name, SYSCALL_ENTRY_STR,
LTTNG_KERNEL_SYM_NAME_LEN);
break;
case SC_TYPE_EXIT:
strncpy(ev.name, SYSCALL_EXIT_STR,
LTTNG_KERNEL_SYM_NAME_LEN);
break;
case SC_TYPE_COMPAT_ENTRY:
strncpy(ev.name, COMPAT_SYSCALL_ENTRY_STR,
LTTNG_KERNEL_SYM_NAME_LEN);
break;
case SC_TYPE_COMPAT_EXIT:
strncpy(ev.name, COMPAT_SYSCALL_EXIT_STR,
LTTNG_KERNEL_SYM_NAME_LEN);
break;
default:
BUG_ON(1);
break;
}
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_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])) {
/*
* If something goes wrong in event registration
* after the first one, we have no choice but to
* leave the previous events in there, until
* deleted by session teardown.
*/
return PTR_ERR(chan_table[i]);
}
}
return 0;
}
/*
* Should be called with sessions lock held.
*/
int lttng_syscalls_register(struct lttng_channel *chan, void *filter)
{
struct lttng_kernel_event ev;
int ret;
wrapper_vmalloc_sync_all();
if (!chan->sc_table) {
/* create syscall table mapping syscall to events */
chan->sc_table = kzalloc(sizeof(struct lttng_event *)
* ARRAY_SIZE(sc_table), GFP_KERNEL);
if (!chan->sc_table)
return -ENOMEM;
}
if (!chan->sc_exit_table) {
/* create syscall table mapping syscall to events */
chan->sc_exit_table = kzalloc(sizeof(struct lttng_event *)
* ARRAY_SIZE(sc_exit_table), GFP_KERNEL);
if (!chan->sc_exit_table)
return -ENOMEM;
}
#ifdef CONFIG_COMPAT
if (!chan->compat_sc_table) {
/* create syscall table mapping compat syscall to events */
chan->compat_sc_table = kzalloc(sizeof(struct lttng_event *)
* ARRAY_SIZE(compat_sc_table), GFP_KERNEL);
if (!chan->compat_sc_table)
return -ENOMEM;
}
if (!chan->compat_sc_exit_table) {
/* create syscall table mapping compat syscall to events */
chan->compat_sc_exit_table = kzalloc(sizeof(struct lttng_event *)
* ARRAY_SIZE(compat_sc_exit_table), GFP_KERNEL);
if (!chan->compat_sc_exit_table)
return -ENOMEM;
}
#endif
if (!chan->sc_unknown) {
const struct lttng_event_desc *desc =
&__event_desc___syscall_entry_unknown;
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_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);
}
}
if (!chan->sc_compat_unknown) {
const struct lttng_event_desc *desc =
&__event_desc___compat_syscall_entry_unknown;
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_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);
}
}
if (!chan->compat_sc_exit_unknown) {
const struct lttng_event_desc *desc =
&__event_desc___compat_syscall_exit_unknown;
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_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);
}
}
if (!chan->sc_exit_unknown) {
const struct lttng_event_desc *desc =
&__event_desc___syscall_exit_unknown;
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_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);
}
}
ret = fill_table(sc_table, ARRAY_SIZE(sc_table),
chan->sc_table, chan, filter, SC_TYPE_ENTRY);
if (ret)
return ret;
ret = fill_table(sc_exit_table, ARRAY_SIZE(sc_exit_table),
chan->sc_exit_table, chan, filter, SC_TYPE_EXIT);
if (ret)
return ret;
#ifdef CONFIG_COMPAT
ret = fill_table(compat_sc_table, ARRAY_SIZE(compat_sc_table),
chan->compat_sc_table, chan, filter,
SC_TYPE_COMPAT_ENTRY);
if (ret)
return ret;
ret = fill_table(compat_sc_exit_table, ARRAY_SIZE(compat_sc_exit_table),
chan->compat_sc_exit_table, chan, filter,
SC_TYPE_COMPAT_EXIT);
if (ret)
return ret;
#endif
if (!chan->sys_enter_registered) {
ret = lttng_wrapper_tracepoint_probe_register("sys_enter",
(void *) syscall_entry_probe, chan);
if (ret)
return ret;
chan->sys_enter_registered = 1;
}
/*
* We change the name of sys_exit tracepoint due to namespace
* conflict with sys_exit syscall entry.
*/
if (!chan->sys_exit_registered) {
ret = lttng_wrapper_tracepoint_probe_register("sys_exit",
(void *) syscall_exit_probe, chan);
if (ret) {
WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter",
(void *) syscall_entry_probe, chan));
return ret;
}
chan->sys_exit_registered = 1;
}
return ret;
}
/*
* Only called at session destruction.
*/
int lttng_syscalls_unregister(struct lttng_channel *chan)
{
int ret;
if (!chan->sc_table)
return 0;
if (chan->sys_enter_registered) {
ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit",
(void *) syscall_exit_probe, chan);
if (ret)
return ret;
chan->sys_enter_registered = 0;
}
if (chan->sys_exit_registered) {
ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter",
(void *) syscall_entry_probe, chan);
if (ret)
return ret;
chan->sys_exit_registered = 0;
}
/* lttng_event destroy will be performed by lttng_session_destroy() */
kfree(chan->sc_table);
kfree(chan->sc_exit_table);
#ifdef CONFIG_COMPAT
kfree(chan->compat_sc_table);
kfree(chan->compat_sc_exit_table);
#endif
kfree(chan->sc_filter);
return 0;
}
static
int get_syscall_nr(const char *syscall_name)
{
int syscall_nr = -1;
int i;
for (i = 0; i < ARRAY_SIZE(sc_table); i++) {
const struct trace_syscall_entry *entry;
const char *it_name;
entry = &sc_table[i];
if (!entry->desc)
continue;
it_name = entry->desc->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;