+++ /dev/null
-/*
- * 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 <asm/ptrace.h>
-#include <asm/syscall.h>
-
-#include "lttng-events.h"
-
-#ifndef CONFIG_COMPAT
-# ifndef is_compat_task
-# define is_compat_task() (0)
-# endif
-#endif
-
-static
-void syscall_entry_probe(void *__data, struct pt_regs *regs, long id);
-
-/*
- * Take care of NOARGS not supported by mainline.
- */
-#define DECLARE_EVENT_CLASS_NOARGS(name, tstruct, assign, print)
-#define DEFINE_EVENT_NOARGS(template, name)
-#define TRACE_EVENT_NOARGS(name, struct, assign, print)
-
-/*
- * Create LTTng tracepoint probes.
- */
-#define LTTNG_PACKAGE_BUILD
-#define CREATE_TRACE_POINTS
-#define TP_MODULE_OVERRIDE
-#define TRACE_INCLUDE_PATH ../instrumentation/syscalls/headers
-
-#define PARAMS(args...) args
-
-/* Hijack probe callback for system calls */
-#undef TP_PROBE_CB
-#define TP_PROBE_CB(_template) &syscall_entry_probe
-#define SC_TRACE_EVENT(_name, _proto, _args, _struct, _assign, _printk) \
- TRACE_EVENT(_name, PARAMS(_proto), PARAMS(_args),\
- PARAMS(_struct), PARAMS(_assign), PARAMS(_printk))
-#define SC_DECLARE_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \
- DECLARE_EVENT_CLASS_NOARGS(_name, PARAMS(_struct), PARAMS(_assign),\
- PARAMS(_printk))
-#define SC_DEFINE_EVENT_NOARGS(_template, _name) \
- DEFINE_EVENT_NOARGS(_template, _name)
-#undef TRACE_SYSTEM
-#define TRACE_SYSTEM syscalls_integers
-#include "instrumentation/syscalls/headers/syscalls_integers.h"
-#undef TRACE_SYSTEM
-#define TRACE_SYSTEM syscalls_pointers
-#include "instrumentation/syscalls/headers/syscalls_pointers.h"
-#undef TRACE_SYSTEM
-#undef SC_TRACE_EVENT
-#undef SC_DECLARE_EVENT_CLASS_NOARGS
-#undef SC_DEFINE_EVENT_NOARGS
-
-#define TRACE_SYSTEM syscalls_unknown
-#include "instrumentation/syscalls/headers/syscalls_unknown.h"
-#undef TRACE_SYSTEM
-
-/* For compat syscalls */
-#undef _TRACE_SYSCALLS_integers_H
-#undef _TRACE_SYSCALLS_pointers_H
-
-/* Hijack probe callback for system calls */
-#undef TP_PROBE_CB
-#define TP_PROBE_CB(_template) &syscall_entry_probe
-#define SC_TRACE_EVENT(_name, _proto, _args, _struct, _assign, _printk) \
- TRACE_EVENT(compat_##_name, PARAMS(_proto), PARAMS(_args), \
- PARAMS(_struct), PARAMS(_assign), \
- PARAMS(_printk))
-#define SC_DECLARE_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \
- DECLARE_EVENT_CLASS_NOARGS(compat_##_name, PARAMS(_struct), \
- PARAMS(_assign), PARAMS(_printk))
-#define SC_DEFINE_EVENT_NOARGS(_template, _name) \
- DEFINE_EVENT_NOARGS(compat_##_template, compat_##_name)
-#define TRACE_SYSTEM compat_syscalls_integers
-#include "instrumentation/syscalls/headers/compat_syscalls_integers.h"
-#undef TRACE_SYSTEM
-#define TRACE_SYSTEM compat_syscalls_pointers
-#include "instrumentation/syscalls/headers/compat_syscalls_pointers.h"
-#undef TRACE_SYSTEM
-#undef SC_TRACE_EVENT
-#undef SC_DECLARE_EVENT_CLASS_NOARGS
-#undef SC_DEFINE_EVENT_NOARGS
-#undef TP_PROBE_CB
-
-#undef TP_MODULE_OVERRIDE
-#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
-
-#undef TRACE_SYSCALL_TABLE
-#define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
- [ _nr ] = { \
- .func = __event_probe__##_template, \
- .nrargs = (_nrargs), \
- .fields = __event_fields___##_template, \
- .desc = &__event_desc___##_name, \
- },
-
-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_##_template, \
- .nrargs = (_nrargs), \
- .fields = __event_fields___##compat_##_template,\
- .desc = &__event_desc___##compat_##_name, \
- },
-
-/* Create compatibility syscall 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 CREATE_SYSCALL_TABLE
-
-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(is_compat_task()))
- __event_probe__compat_sys_unknown(event, id, args);
- else
- __event_probe__sys_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;
-
- if (unlikely(is_compat_task())) {
- table = compat_sc_table;
- table_len = ARRAY_SIZE(compat_sc_table);
- unknown_event = chan->sc_compat_unknown;
- } else {
- table = sc_table;
- table_len = ARRAY_SIZE(sc_table);
- unknown_event = chan->sc_unknown;
- }
- if (unlikely(id >= table_len)) {
- syscall_entry_unknown(unknown_event, regs, id);
- return;
- }
- if (unlikely(is_compat_task()))
- 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;
- }
-}
-
-/* noinline to diminish caller stack size */
-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)
-{
- 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));
- 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_table[i] = lttng_event_create(chan, &ev, filter,
- desc);
- if (!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 -EINVAL;
- }
- }
- return 0;
-}
-
-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;
- }
-
-#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;
- }
-#endif
- if (!chan->sc_unknown) {
- const struct lttng_event_desc *desc =
- &__event_desc___sys_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_NOOP;
- chan->sc_unknown = lttng_event_create(chan, &ev, filter,
- desc);
- if (!chan->sc_unknown) {
- return -EINVAL;
- }
- }
-
- if (!chan->sc_compat_unknown) {
- const struct lttng_event_desc *desc =
- &__event_desc___compat_sys_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_NOOP;
- chan->sc_compat_unknown = lttng_event_create(chan, &ev, filter,
- desc);
- if (!chan->sc_compat_unknown) {
- return -EINVAL;
- }
- }
-
- if (!chan->sc_exit) {
- const struct lttng_event_desc *desc =
- &__event_desc___exit_syscall;
-
- 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 = lttng_event_create(chan, &ev, filter,
- desc);
- if (!chan->sc_exit) {
- return -EINVAL;
- }
- }
-
- ret = fill_table(sc_table, ARRAY_SIZE(sc_table),
- chan->sc_table, chan, filter);
- if (ret)
- return ret;
-#ifdef CONFIG_COMPAT
- ret = fill_table(compat_sc_table, ARRAY_SIZE(compat_sc_table),
- chan->compat_sc_table, chan, filter);
- if (ret)
- return ret;
-#endif
- ret = tracepoint_probe_register("sys_enter",
- (void *) syscall_entry_probe, chan);
- if (ret)
- return ret;
- /*
- * We change the name of sys_exit tracepoint due to namespace
- * conflict with sys_exit syscall entry.
- */
- ret = tracepoint_probe_register("sys_exit",
- (void *) __event_probe__exit_syscall,
- chan->sc_exit);
- if (ret) {
- WARN_ON_ONCE(tracepoint_probe_unregister("sys_enter",
- (void *) syscall_entry_probe, chan));
- }
- return ret;
-}
-
-/*
- * Only called at session destruction.
- */
-int lttng_syscalls_unregister(struct lttng_channel *chan)
-{
- int ret;
-
- if (!chan->sc_table)
- return 0;
- ret = tracepoint_probe_unregister("sys_exit",
- (void *) __event_probe__exit_syscall,
- chan->sc_exit);
- if (ret)
- return ret;
- ret = tracepoint_probe_unregister("sys_enter",
- (void *) syscall_entry_probe, chan);
- if (ret)
- return ret;
- /* lttng_event destroy will be performed by lttng_session_destroy() */
- kfree(chan->sc_table);
-#ifdef CONFIG_COMPAT
- kfree(chan->compat_sc_table);
-#endif
- return 0;
-}
projects / lttng-modules.git / blobdiff