tracing: Add individual syscalls tracepoint id support

The current state of syscalls tracepoints generates only one event id
for every syscall events.

This patch associates an id with each syscall trace event, so that we
can identify each syscall trace event using the 'perf' tool.

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>

2 files changed, 16 insertions, 16 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index d682357e4b1f..300ef788c976 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -34,8 +34,6 @@ enum trace_type {
         TRACE_GRAPH_ENT,
         TRACE_USER_STACK,
         TRACE_HW_BRANCHES,
-        TRACE_SYSCALL_ENTER,
-        TRACE_SYSCALL_EXIT,
         TRACE_KMEM_ALLOC,
         TRACE_KMEM_FREE,
         TRACE_POWER,
@@ -319,10 +317,6 @@ extern void __ftrace_bad_type(void);
                           TRACE_KMEM_ALLOC);    \
                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
                           TRACE_KMEM_FREE);     \
-                IF_ASSIGN(var, ent, struct syscall_trace_enter,         \
-                          TRACE_SYSCALL_ENTER);                         \
-                IF_ASSIGN(var, ent, struct syscall_trace_exit,          \
-                          TRACE_SYSCALL_EXIT);                          \
                 __ftrace_bad_type();                                    \
         } while (0)
 
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index c7ae25ee95d8..e58a9c11ba85 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -36,14 +36,18 @@ print_syscall_enter(struct trace_iterator *iter, int flags)
         struct syscall_metadata *entry;
         int i, ret, syscall;
 
-        trace_assign_type(trace, ent);
-
+        trace = (typeof(trace))ent;
         syscall = trace->nr;
-
         entry = syscall_nr_to_meta(syscall);
+
         if (!entry)
                 goto end;
 
+        if (entry->enter_id != ent->type) {
+                WARN_ON_ONCE(1);
+                goto end;
+        }
+
         ret = trace_seq_printf(s, "%s(", entry->name);
         if (!ret)
                 return TRACE_TYPE_PARTIAL_LINE;
@@ -78,16 +82,20 @@ print_syscall_exit(struct trace_iterator *iter, int flags)
         struct syscall_metadata *entry;
         int ret;
 
-        trace_assign_type(trace, ent);
-
+        trace = (typeof(trace))ent;
         syscall = trace->nr;
-
         entry = syscall_nr_to_meta(syscall);
+
         if (!entry) {
                 trace_seq_printf(s, "\n");
                 return TRACE_TYPE_HANDLED;
         }
 
+        if (entry->exit_id != ent->type) {
+                WARN_ON_ONCE(1);
+                return TRACE_TYPE_UNHANDLED;
+        }
+
         ret = trace_seq_printf(s, "%s -> 0x%lx\n", entry->name,
                                 trace->ret);
         if (!ret)
@@ -114,7 +122,7 @@ void ftrace_syscall_enter(struct pt_regs *regs, long id)
 
         size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;
 
-        event = trace_current_buffer_lock_reserve(TRACE_SYSCALL_ENTER, size,
+        event = trace_current_buffer_lock_reserve(sys_data->enter_id, size,
                                                         0, 0);
         if (!event)
                 return;
@@ -142,7 +150,7 @@ void ftrace_syscall_exit(struct pt_regs *regs, long ret)
         if (!sys_data)
                 return;
 
-        event = trace_current_buffer_lock_reserve(TRACE_SYSCALL_EXIT,
+        event = trace_current_buffer_lock_reserve(sys_data->exit_id,
                                 sizeof(*entry), 0, 0);
         if (!event)
                 return;
@@ -239,10 +247,8 @@ void unreg_event_syscall_exit(void *ptr)
 
 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
 };