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#include <trace/syscall.h>
#include <linux/kernel.h>
#include <linux/ftrace.h>
#include <asm/syscall.h>
#include "trace_output.h"
#include "trace.h"
static DEFINE_MUTEX(syscall_trace_lock);
static int sys_refcount_enter;
static int sys_refcount_exit;
static DECLARE_BITMAP(enabled_enter_syscalls, FTRACE_SYSCALL_MAX);
static DECLARE_BITMAP(enabled_exit_syscalls, FTRACE_SYSCALL_MAX);
/* Option to display the parameters types */
enum {
TRACE_SYSCALLS_OPT_TYPES = 0x1,
};
static struct tracer_opt syscalls_opts[] = {
{ TRACER_OPT(syscall_arg_type, TRACE_SYSCALLS_OPT_TYPES) },
{ }
};
static struct tracer_flags syscalls_flags = {
.val = 0, /* By default: no parameters types */
.opts = syscalls_opts
};
enum print_line_t
print_syscall_enter(struct trace_iterator *iter, int flags)
{
struct trace_seq *s = &iter->seq;
struct trace_entry *ent = iter->ent;
struct syscall_trace_enter *trace;
struct syscall_metadata *entry;
int i, ret, syscall;
trace_assign_type(trace, ent);
syscall = trace->nr;
entry = syscall_nr_to_meta(syscall);
if (!entry)
goto end;
ret = trace_seq_printf(s, "%s(", entry->name);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
for (i = 0; i < entry->nb_args; i++) {
/* parameter types */
if (syscalls_flags.val & TRACE_SYSCALLS_OPT_TYPES) {
ret = trace_seq_printf(s, "%s ", entry->types[i]);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
/* parameter values */
ret = trace_seq_printf(s, "%s: %lx%s ", entry->args[i],
trace->args[i],
i == entry->nb_args - 1 ? ")" : ",");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
end:
trace_seq_printf(s, "\n");
return TRACE_TYPE_HANDLED;
}
enum print_line_t
print_syscall_exit(struct trace_iterator *iter, int flags)
{
struct trace_seq *s = &iter->seq;
struct trace_entry *ent = iter->ent;
struct syscall_trace_exit *trace;
int syscall;
struct syscall_metadata *entry;
int ret;
trace_assign_type(trace, ent);
syscall = trace->nr;
entry = syscall_nr_to_meta(syscall);
if (!entry) {
trace_seq_printf(s, "\n");
return TRACE_TYPE_HANDLED;
}
ret = trace_seq_printf(s, "%s -> 0x%lx\n", entry->name,
trace->ret);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
}
void ftrace_syscall_enter(struct pt_regs *regs, long id)
{
struct syscall_trace_enter *entry;
struct syscall_metadata *sys_data;
struct ring_buffer_event *event;
int size;
int syscall_nr;
syscall_nr = syscall_get_nr(current, regs);
if (!test_bit(syscall_nr, enabled_enter_syscalls))
return;
sys_data = syscall_nr_to_meta(syscall_nr);
if (!sys_data)
return;
size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;
event = trace_current_buffer_lock_reserve(TRACE_SYSCALL_ENTER, size,
0, 0);
if (!event)
return;
entry = ring_buffer_event_data(event);
entry->nr = syscall_nr;
syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
trace_current_buffer_unlock_commit(event, 0, 0);
trace_wake_up();
}
void ftrace_syscall_exit(struct pt_regs *regs, long ret)
{
struct syscall_trace_exit *entry;
struct syscall_metadata *sys_data;
struct ring_buffer_event *event;
int syscall_nr;
syscall_nr = syscall_get_nr(current, regs);
if (!test_bit(syscall_nr, enabled_exit_syscalls))
return;
sys_data = syscall_nr_to_meta(syscall_nr);
if (!sys_data)
return;
event = trace_current_buffer_lock_reserve(TRACE_SYSCALL_EXIT,
sizeof(*entry), 0, 0);
if (!event)
return;
entry = ring_buffer_event_data(event);
entry->nr = syscall_nr;
entry->ret = syscall_get_return_value(current, regs);
trace_current_buffer_unlock_commit(event, 0, 0);
trace_wake_up();
}
int reg_event_syscall_enter(void *ptr)
{
int ret = 0;
int num;
char *name;
name = (char *)ptr;
num = syscall_name_to_nr(name);
if (num < 0 || num >= FTRACE_SYSCALL_MAX)
return -ENOSYS;
mutex_lock(&syscall_trace_lock);
if (!sys_refcount_enter)
ret = register_trace_syscall_enter(ftrace_syscall_enter);
if (ret) {
pr_info("event trace: Could not activate"
"syscall entry trace point");
} else {
set_bit(num, enabled_enter_syscalls);
sys_refcount_enter++;
}
mutex_unlock(&syscall_trace_lock);
return ret;
}
void unreg_event_syscall_enter(void *ptr)
{
int num;
char *name;
name = (char *)ptr;
num = syscall_name_to_nr(name);
if (num < 0 || num >= FTRACE_SYSCALL_MAX)
return;
mutex_lock(&syscall_trace_lock);
sys_refcount_enter--;
clear_bit(num, enabled_enter_syscalls);
if (!sys_refcount_enter)
unregister_trace_syscall_enter(ftrace_syscall_enter);
mutex_unlock(&syscall_trace_lock);
}
int reg_event_syscall_exit(void *ptr)
{
int ret = 0;
int num;
char *name;
name = (char *)ptr;
num = syscall_name_to_nr(name);
if (num < 0 || num >= FTRACE_SYSCALL_MAX)
return -ENOSYS;
mutex_lock(&syscall_trace_lock);
if (!sys_refcount_exit)
ret = register_trace_syscall_exit(ftrace_syscall_exit);
if (ret) {
pr_info("event trace: Could not activate"
"syscall exit trace point");
} else {
set_bit(num, enabled_exit_syscalls);
sys_refcount_exit++;
}
mutex_unlock(&syscall_trace_lock);
return ret;
}
void unreg_event_syscall_exit(void *ptr)
{
int num;
char *name;
name = (char *)ptr;
num = syscall_name_to_nr(name);
if (num < 0 || num >= FTRACE_SYSCALL_MAX)
return;
mutex_lock(&syscall_trace_lock);
sys_refcount_exit--;
clear_bit(num, enabled_exit_syscalls);
if (!sys_refcount_exit)
unregister_trace_syscall_exit(ftrace_syscall_exit);
mutex_unlock(&syscall_trace_lock);
}
struct trace_event event_syscall_enter = {
.trace = print_syscall_enter,
.type = TRACE_SYSCALL_ENTER
};
struct trace_event event_syscall_exit = {
.trace = print_syscall_exit,
.type = TRACE_SYSCALL_EXIT
};
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