tracing: Add trace events for each syscall entry/exit
Layer Frederic's syscall tracer on tracepoints. We create trace events
via hooking into the SYSCALL_DEFINE macros. This allows us to
individually toggle syscall entry and exit points on/off.
Signed-off-by: Jason Baron <jbaron@redhat.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 80de700..5e5b4d3 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -64,6 +64,7 @@
#include <linux/sem.h>
#include <asm/siginfo.h>
#include <asm/signal.h>
+#include <linux/unistd.h>
#include <linux/quota.h>
#include <linux/key.h>
#include <trace/syscall.h>
@@ -112,6 +113,59 @@
#define __SC_STR_TDECL5(t, a, ...) #t, __SC_STR_TDECL4(__VA_ARGS__)
#define __SC_STR_TDECL6(t, a, ...) #t, __SC_STR_TDECL5(__VA_ARGS__)
+
+#define SYSCALL_TRACE_ENTER_EVENT(sname) \
+ static struct ftrace_event_call event_enter_##sname; \
+ static int init_enter_##sname(void) \
+ { \
+ int num; \
+ num = syscall_name_to_nr("sys"#sname); \
+ if (num < 0) \
+ return -ENOSYS; \
+ register_ftrace_event(&event_syscall_enter); \
+ INIT_LIST_HEAD(&event_enter_##sname.fields); \
+ init_preds(&event_enter_##sname); \
+ return 0; \
+ } \
+ static struct ftrace_event_call __used \
+ __attribute__((__aligned__(4))) \
+ __attribute__((section("_ftrace_events"))) \
+ event_enter_##sname = { \
+ .name = "sys_enter"#sname, \
+ .system = "syscalls", \
+ .event = &event_syscall_enter, \
+ .raw_init = init_enter_##sname, \
+ .regfunc = reg_event_syscall_enter, \
+ .unregfunc = unreg_event_syscall_enter, \
+ .data = "sys"#sname, \
+ }
+
+#define SYSCALL_TRACE_EXIT_EVENT(sname) \
+ static struct ftrace_event_call event_exit_##sname; \
+ static int init_exit_##sname(void) \
+ { \
+ int num; \
+ num = syscall_name_to_nr("sys"#sname); \
+ if (num < 0) \
+ return -ENOSYS; \
+ register_ftrace_event(&event_syscall_exit); \
+ INIT_LIST_HEAD(&event_exit_##sname.fields); \
+ init_preds(&event_exit_##sname); \
+ return 0; \
+ } \
+ static struct ftrace_event_call __used \
+ __attribute__((__aligned__(4))) \
+ __attribute__((section("_ftrace_events"))) \
+ event_exit_##sname = { \
+ .name = "sys_exit"#sname, \
+ .system = "syscalls", \
+ .event = &event_syscall_exit, \
+ .raw_init = init_exit_##sname, \
+ .regfunc = reg_event_syscall_exit, \
+ .unregfunc = unreg_event_syscall_exit, \
+ .data = "sys"#sname, \
+ }
+
#define SYSCALL_METADATA(sname, nb) \
static const struct syscall_metadata __used \
__attribute__((__aligned__(4))) \
@@ -121,7 +175,9 @@
.nb_args = nb, \
.types = types_##sname, \
.args = args_##sname, \
- }
+ }; \
+ SYSCALL_TRACE_ENTER_EVENT(sname); \
+ SYSCALL_TRACE_EXIT_EVENT(sname);
#define SYSCALL_DEFINE0(sname) \
static const struct syscall_metadata __used \
@@ -131,8 +187,9 @@
.name = "sys_"#sname, \
.nb_args = 0, \
}; \
+ SYSCALL_TRACE_ENTER_EVENT(_##sname); \
+ SYSCALL_TRACE_EXIT_EVENT(_##sname); \
asmlinkage long sys_##sname(void)
-
#else
#define SYSCALL_DEFINE0(name) asmlinkage long sys_##name(void)
#endif
diff --git a/include/trace/syscall.h b/include/trace/syscall.h
index 3951d774..73fb8b4 100644
--- a/include/trace/syscall.h
+++ b/include/trace/syscall.h
@@ -2,6 +2,8 @@
#define _TRACE_SYSCALL_H
#include <linux/tracepoint.h>
+#include <linux/unistd.h>
+#include <linux/ftrace_event.h>
#include <asm/ptrace.h>
@@ -40,15 +42,13 @@
#ifdef CONFIG_FTRACE_SYSCALLS
extern struct syscall_metadata *syscall_nr_to_meta(int nr);
-extern void start_ftrace_syscalls(void);
-extern void stop_ftrace_syscalls(void);
-extern void ftrace_syscall_enter(struct pt_regs *regs);
-extern void ftrace_syscall_exit(struct pt_regs *regs);
-#else
-static inline void start_ftrace_syscalls(void) { }
-static inline void stop_ftrace_syscalls(void) { }
-static inline void ftrace_syscall_enter(struct pt_regs *regs) { }
-static inline void ftrace_syscall_exit(struct pt_regs *regs) { }
+extern int syscall_name_to_nr(char *name);
+extern struct trace_event event_syscall_enter;
+extern struct trace_event event_syscall_exit;
+extern int reg_event_syscall_enter(void *ptr);
+extern void unreg_event_syscall_enter(void *ptr);
+extern int reg_event_syscall_exit(void *ptr);
+extern void unreg_event_syscall_exit(void *ptr);
#endif
#endif /* _TRACE_SYSCALL_H */