--- /dev/null
+#include <linux/kernel.h>
+#include <linux/ftrace.h>
+#include <asm/syscall.h>
+
+#include "trace_output.h"
+#include "trace.h"
+
+/* Keep a counter of the syscall tracing users */
+static int refcount;
+
+/* Prevent from races on thread flags toggling */
+static DEFINE_MUTEX(syscall_trace_lock);
+
+/* 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 start_ftrace_syscalls(void)
+{
+ unsigned long flags;
+ struct task_struct *g, *t;
+
+ mutex_lock(&syscall_trace_lock);
+
+ /* Don't enable the flag on the tasks twice */
+ if (++refcount != 1)
+ goto unlock;
+
+ arch_init_ftrace_syscalls();
+ read_lock_irqsave(&tasklist_lock, flags);
+
+ do_each_thread(g, t) {
+ set_tsk_thread_flag(t, TIF_SYSCALL_FTRACE);
+ } while_each_thread(g, t);
+
+ read_unlock_irqrestore(&tasklist_lock, flags);
+
+unlock:
+ mutex_unlock(&syscall_trace_lock);
+}
+
+void stop_ftrace_syscalls(void)
+{
+ unsigned long flags;
+ struct task_struct *g, *t;
+
+ mutex_lock(&syscall_trace_lock);
+
+ /* There are perhaps still some users */
+ if (--refcount)
+ goto unlock;
+
+ read_lock_irqsave(&tasklist_lock, flags);
+
+ do_each_thread(g, t) {
+ clear_tsk_thread_flag(t, TIF_SYSCALL_FTRACE);
+ } while_each_thread(g, t);
+
+ read_unlock_irqrestore(&tasklist_lock, flags);
+
+unlock:
+ mutex_unlock(&syscall_trace_lock);
+}
+
+void ftrace_syscall_enter(struct pt_regs *regs)
+{
+ 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);
+
+ 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)
+{
+ 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);
+
+ 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();
+}
+
+static int init_syscall_tracer(struct trace_array *tr)
+{
+ start_ftrace_syscalls();
+
+ return 0;
+}
+
+static void reset_syscall_tracer(struct trace_array *tr)
+{
+ stop_ftrace_syscalls();
+ tracing_reset_online_cpus(tr);
+}
+
+static struct trace_event syscall_enter_event = {
+ .type = TRACE_SYSCALL_ENTER,
+ .trace = print_syscall_enter,
+};
+
+static struct trace_event syscall_exit_event = {
+ .type = TRACE_SYSCALL_EXIT,
+ .trace = print_syscall_exit,
+};
+
+static struct tracer syscall_tracer __read_mostly = {
+ .name = "syscall",
+ .init = init_syscall_tracer,
+ .reset = reset_syscall_tracer,
+ .flags = &syscalls_flags,
+};
+
+__init int register_ftrace_syscalls(void)
+{
+ int ret;
+
+ ret = register_ftrace_event(&syscall_enter_event);
+ if (!ret) {
+ printk(KERN_WARNING "event %d failed to register\n",
+ syscall_enter_event.type);
+ WARN_ON_ONCE(1);
+ }
+
+ ret = register_ftrace_event(&syscall_exit_event);
+ if (!ret) {
+ printk(KERN_WARNING "event %d failed to register\n",
+ syscall_exit_event.type);
+ WARN_ON_ONCE(1);
+ }
+
+ return register_tracer(&syscall_tracer);
+}
+device_initcall(register_ftrace_syscalls);
projects / linux-2.6-omap-h63xx.git / blobdiff