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lttng: add system call instrumentation probe
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Mathieu Desnoyers
Greg Kroah-Hartman
parent
18b2248a0d
commit
97104e24fb
438
drivers/staging/lttng/lttng-syscalls.c
Normal file
438
drivers/staging/lttng/lttng-syscalls.c
Normal file
@ -0,0 +1,438 @@
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/*
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* lttng-syscalls.c
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*
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* Copyright 2010-2011 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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*
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* LTTng syscall probes.
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*
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* Dual LGPL v2.1/GPL v2 license.
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*/
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/compat.h>
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#include <asm/ptrace.h>
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#include <asm/syscall.h>
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#include "ltt-events.h"
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#ifndef CONFIG_COMPAT
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static inline int is_compat_task(void)
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{
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return 0;
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}
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#endif
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static
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void syscall_entry_probe(void *__data, struct pt_regs *regs, long id);
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/*
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* Take care of NOARGS not supported by mainline.
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*/
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#define DECLARE_EVENT_CLASS_NOARGS(name, tstruct, assign, print)
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#define DEFINE_EVENT_NOARGS(template, name)
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#define TRACE_EVENT_NOARGS(name, struct, assign, print)
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/*
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* Create LTTng tracepoint probes.
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*/
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#define LTTNG_PACKAGE_BUILD
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#define CREATE_TRACE_POINTS
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#define TP_MODULE_OVERRIDE
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#define TRACE_INCLUDE_PATH ../instrumentation/syscalls/headers
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#define PARAMS(args...) args
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#undef TRACE_SYSTEM
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/* Hijack probe callback for system calls */
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#undef TP_PROBE_CB
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#define TP_PROBE_CB(_template) &syscall_entry_probe
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#define SC_TRACE_EVENT(_name, _proto, _args, _struct, _assign, _printk) \
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TRACE_EVENT(_name, PARAMS(_proto), PARAMS(_args),\
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PARAMS(_struct), PARAMS(_assign), PARAMS(_printk))
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#define SC_DECLARE_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \
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DECLARE_EVENT_CLASS_NOARGS(_name, PARAMS(_struct), PARAMS(_assign),\
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PARAMS(_printk))
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#define SC_DEFINE_EVENT_NOARGS(_template, _name) \
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DEFINE_EVENT_NOARGS(_template, _name)
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#define TRACE_SYSTEM syscalls_integers
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#include "instrumentation/syscalls/headers/syscalls_integers.h"
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#undef TRACE_SYSTEM
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#define TRACE_SYSTEM syscalls_pointers
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#include "instrumentation/syscalls/headers/syscalls_pointers.h"
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#undef TRACE_SYSTEM
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#undef SC_TRACE_EVENT
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#undef SC_DECLARE_EVENT_CLASS_NOARGS
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#undef SC_DEFINE_EVENT_NOARGS
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#define TRACE_SYSTEM syscalls_unknown
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#include "instrumentation/syscalls/headers/syscalls_unknown.h"
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#undef TRACE_SYSTEM
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/* For compat syscalls */
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#undef _TRACE_SYSCALLS_integers_H
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#undef _TRACE_SYSCALLS_pointers_H
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/* Hijack probe callback for system calls */
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#undef TP_PROBE_CB
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#define TP_PROBE_CB(_template) &syscall_entry_probe
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#define SC_TRACE_EVENT(_name, _proto, _args, _struct, _assign, _printk) \
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TRACE_EVENT(compat_##_name, PARAMS(_proto), PARAMS(_args), \
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PARAMS(_struct), PARAMS(_assign), \
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PARAMS(_printk))
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#define SC_DECLARE_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \
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DECLARE_EVENT_CLASS_NOARGS(compat_##_name, PARAMS(_struct), \
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PARAMS(_assign), PARAMS(_printk))
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#define SC_DEFINE_EVENT_NOARGS(_template, _name) \
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DEFINE_EVENT_NOARGS(compat_##_template, compat_##_name)
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#define TRACE_SYSTEM compat_syscalls_integers
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#include "instrumentation/syscalls/headers/compat_syscalls_integers.h"
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#undef TRACE_SYSTEM
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#define TRACE_SYSTEM compat_syscalls_pointers
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#include "instrumentation/syscalls/headers/compat_syscalls_pointers.h"
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#undef TRACE_SYSTEM
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#undef SC_TRACE_EVENT
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#undef SC_DECLARE_EVENT_CLASS_NOARGS
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#undef SC_DEFINE_EVENT_NOARGS
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#undef TP_PROBE_CB
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#undef TP_MODULE_OVERRIDE
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#undef LTTNG_PACKAGE_BUILD
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#undef CREATE_TRACE_POINTS
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struct trace_syscall_entry {
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void *func;
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const struct lttng_event_desc *desc;
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const struct lttng_event_field *fields;
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unsigned int nrargs;
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};
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#define CREATE_SYSCALL_TABLE
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#undef TRACE_SYSCALL_TABLE
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#define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
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[ _nr ] = { \
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.func = __event_probe__##_template, \
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.nrargs = (_nrargs), \
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.fields = __event_fields___##_template, \
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.desc = &__event_desc___##_name, \
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},
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static const struct trace_syscall_entry sc_table[] = {
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#include "instrumentation/syscalls/headers/syscalls_integers.h"
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#include "instrumentation/syscalls/headers/syscalls_pointers.h"
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};
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#undef TRACE_SYSCALL_TABLE
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#define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
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[ _nr ] = { \
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.func = __event_probe__##compat_##_template, \
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.nrargs = (_nrargs), \
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.fields = __event_fields___##compat_##_template,\
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.desc = &__event_desc___##compat_##_name, \
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},
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/* Create compatibility syscall table */
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const struct trace_syscall_entry compat_sc_table[] = {
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#include "instrumentation/syscalls/headers/compat_syscalls_integers.h"
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#include "instrumentation/syscalls/headers/compat_syscalls_pointers.h"
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};
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#undef CREATE_SYSCALL_TABLE
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static void syscall_entry_unknown(struct ltt_event *event,
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struct pt_regs *regs, unsigned int id)
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{
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unsigned long args[UNKNOWN_SYSCALL_NRARGS];
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syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args);
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if (unlikely(is_compat_task()))
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__event_probe__compat_sys_unknown(event, id, args);
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else
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__event_probe__sys_unknown(event, id, args);
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}
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void syscall_entry_probe(void *__data, struct pt_regs *regs, long id)
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{
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struct ltt_channel *chan = __data;
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struct ltt_event *event, *unknown_event;
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const struct trace_syscall_entry *table, *entry;
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size_t table_len;
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if (unlikely(is_compat_task())) {
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table = compat_sc_table;
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table_len = ARRAY_SIZE(compat_sc_table);
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unknown_event = chan->sc_compat_unknown;
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} else {
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table = sc_table;
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table_len = ARRAY_SIZE(sc_table);
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unknown_event = chan->sc_unknown;
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}
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if (unlikely(id >= table_len)) {
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syscall_entry_unknown(unknown_event, regs, id);
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return;
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}
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if (unlikely(is_compat_task()))
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event = chan->compat_sc_table[id];
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else
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event = chan->sc_table[id];
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if (unlikely(!event)) {
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syscall_entry_unknown(unknown_event, regs, id);
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return;
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}
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entry = &table[id];
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WARN_ON_ONCE(!entry);
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switch (entry->nrargs) {
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case 0:
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{
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void (*fptr)(void *__data) = entry->func;
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fptr(event);
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break;
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}
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case 1:
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{
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void (*fptr)(void *__data, unsigned long arg0) = entry->func;
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unsigned long args[1];
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syscall_get_arguments(current, regs, 0, entry->nrargs, args);
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fptr(event, args[0]);
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break;
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}
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case 2:
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{
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void (*fptr)(void *__data,
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unsigned long arg0,
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unsigned long arg1) = entry->func;
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unsigned long args[2];
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syscall_get_arguments(current, regs, 0, entry->nrargs, args);
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fptr(event, args[0], args[1]);
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break;
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}
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case 3:
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{
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void (*fptr)(void *__data,
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unsigned long arg0,
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unsigned long arg1,
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unsigned long arg2) = entry->func;
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unsigned long args[3];
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syscall_get_arguments(current, regs, 0, entry->nrargs, args);
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fptr(event, args[0], args[1], args[2]);
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break;
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}
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case 4:
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{
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void (*fptr)(void *__data,
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unsigned long arg0,
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unsigned long arg1,
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unsigned long arg2,
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unsigned long arg3) = entry->func;
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unsigned long args[4];
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syscall_get_arguments(current, regs, 0, entry->nrargs, args);
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fptr(event, args[0], args[1], args[2], args[3]);
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break;
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}
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case 5:
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{
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void (*fptr)(void *__data,
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unsigned long arg0,
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unsigned long arg1,
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unsigned long arg2,
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unsigned long arg3,
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unsigned long arg4) = entry->func;
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unsigned long args[5];
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syscall_get_arguments(current, regs, 0, entry->nrargs, args);
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fptr(event, args[0], args[1], args[2], args[3], args[4]);
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break;
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}
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case 6:
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{
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void (*fptr)(void *__data,
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unsigned long arg0,
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unsigned long arg1,
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unsigned long arg2,
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unsigned long arg3,
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unsigned long arg4,
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unsigned long arg5) = entry->func;
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unsigned long args[6];
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syscall_get_arguments(current, regs, 0, entry->nrargs, args);
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fptr(event, args[0], args[1], args[2],
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args[3], args[4], args[5]);
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break;
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}
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default:
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break;
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}
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}
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/* noinline to diminish caller stack size */
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static
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int fill_table(const struct trace_syscall_entry *table, size_t table_len,
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struct ltt_event **chan_table, struct ltt_channel *chan, void *filter)
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{
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const struct lttng_event_desc *desc;
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unsigned int i;
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/* Allocate events for each syscall, insert into table */
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for (i = 0; i < table_len; i++) {
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struct lttng_kernel_event ev;
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desc = table[i].desc;
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if (!desc) {
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/* Unknown syscall */
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continue;
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}
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/*
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* Skip those already populated by previous failed
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* register for this channel.
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*/
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if (chan_table[i])
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continue;
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memset(&ev, 0, sizeof(ev));
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strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN);
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ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0';
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ev.instrumentation = LTTNG_KERNEL_NOOP;
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chan_table[i] = ltt_event_create(chan, &ev, filter,
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desc);
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if (!chan_table[i]) {
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/*
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* If something goes wrong in event registration
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* after the first one, we have no choice but to
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* leave the previous events in there, until
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* deleted by session teardown.
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*/
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return -EINVAL;
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}
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}
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return 0;
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}
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int lttng_syscalls_register(struct ltt_channel *chan, void *filter)
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{
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struct lttng_kernel_event ev;
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int ret;
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wrapper_vmalloc_sync_all();
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if (!chan->sc_table) {
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/* create syscall table mapping syscall to events */
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chan->sc_table = kzalloc(sizeof(struct ltt_event *)
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* ARRAY_SIZE(sc_table), GFP_KERNEL);
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if (!chan->sc_table)
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return -ENOMEM;
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}
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#ifdef CONFIG_COMPAT
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if (!chan->compat_sc_table) {
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/* create syscall table mapping compat syscall to events */
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chan->compat_sc_table = kzalloc(sizeof(struct ltt_event *)
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* ARRAY_SIZE(compat_sc_table), GFP_KERNEL);
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if (!chan->compat_sc_table)
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return -ENOMEM;
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}
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#endif
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if (!chan->sc_unknown) {
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const struct lttng_event_desc *desc =
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&__event_desc___sys_unknown;
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memset(&ev, 0, sizeof(ev));
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strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN);
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ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0';
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ev.instrumentation = LTTNG_KERNEL_NOOP;
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chan->sc_unknown = ltt_event_create(chan, &ev, filter,
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desc);
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if (!chan->sc_unknown) {
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return -EINVAL;
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}
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}
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if (!chan->sc_compat_unknown) {
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const struct lttng_event_desc *desc =
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&__event_desc___compat_sys_unknown;
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memset(&ev, 0, sizeof(ev));
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strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN);
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ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0';
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ev.instrumentation = LTTNG_KERNEL_NOOP;
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chan->sc_compat_unknown = ltt_event_create(chan, &ev, filter,
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desc);
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if (!chan->sc_compat_unknown) {
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return -EINVAL;
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}
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}
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if (!chan->sc_exit) {
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const struct lttng_event_desc *desc =
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&__event_desc___exit_syscall;
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memset(&ev, 0, sizeof(ev));
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strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN);
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ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0';
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ev.instrumentation = LTTNG_KERNEL_NOOP;
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chan->sc_exit = ltt_event_create(chan, &ev, filter,
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desc);
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if (!chan->sc_exit) {
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return -EINVAL;
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}
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}
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ret = fill_table(sc_table, ARRAY_SIZE(sc_table),
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chan->sc_table, chan, filter);
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if (ret)
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return ret;
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#ifdef CONFIG_COMPAT
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ret = fill_table(compat_sc_table, ARRAY_SIZE(compat_sc_table),
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chan->compat_sc_table, chan, filter);
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if (ret)
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return ret;
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#endif
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ret = tracepoint_probe_register("sys_enter",
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(void *) syscall_entry_probe, chan);
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if (ret)
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return ret;
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/*
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* We change the name of sys_exit tracepoint due to namespace
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* conflict with sys_exit syscall entry.
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*/
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ret = tracepoint_probe_register("sys_exit",
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(void *) __event_probe__exit_syscall,
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chan->sc_exit);
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if (ret) {
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WARN_ON_ONCE(tracepoint_probe_unregister("sys_enter",
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(void *) syscall_entry_probe, chan));
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}
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return ret;
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}
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/*
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* Only called at session destruction.
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*/
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int lttng_syscalls_unregister(struct ltt_channel *chan)
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{
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int ret;
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if (!chan->sc_table)
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return 0;
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ret = tracepoint_probe_unregister("sys_exit",
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(void *) __event_probe__exit_syscall,
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chan->sc_exit);
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if (ret)
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return ret;
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ret = tracepoint_probe_unregister("sys_enter",
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(void *) syscall_entry_probe, chan);
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if (ret)
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return ret;
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/* ltt_event destroy will be performed by ltt_session_destroy() */
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kfree(chan->sc_table);
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#ifdef CONFIG_COMPAT
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kfree(chan->compat_sc_table);
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#endif
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return 0;
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}
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