tracing/syscalls: Fix fields format for enter events

The "format" file of a trace event is originally for parsers to
parse ftrace binary output.

But the "format" file of a syscall event can only be used by
perfcounter, because it describes the format of struct
syscall_enter_record not struct syscall_trace_enter.

To fix this, we remove struct syscall_enter_record, and then
struct syscall_trace_enter will be used by both perf profile
and ftrace.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A8BAF39.1030404@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index f130dacfeef46cd69bc38ac303189f6ee0fd5c91..d10daf0922b5e309ec1cea8444ac40b200ec19b8 100644 (file)
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -90,26 +90,39 @@ print_syscall_exit(struct trace_iterator *iter, int flags)
        return TRACE_TYPE_HANDLED;
 }
 
+extern char *__bad_type_size(void);
+
+#define SYSCALL_FIELD(type, name)                                      \
+       sizeof(type) != sizeof(trace.name) ?                            \
+               __bad_type_size() :                                     \
+               #type, #name, offsetof(typeof(trace), name), sizeof(trace.name)
+
 int ftrace_format_syscall(struct ftrace_event_call *call, struct trace_seq *s)
 {
        int i;
        int nr;
-       int ret = 0;
+       int ret;
        struct syscall_metadata *entry;
-       int offset = sizeof(struct trace_entry);
+       struct syscall_trace_enter trace;
+       int offset = offsetof(struct syscall_trace_enter, args);
 
-       nr = syscall_name_to_nr((char *)call->data);
+       nr = syscall_name_to_nr(call->data);
        entry = syscall_nr_to_meta(nr);
 
        if (!entry)
-               return ret;
+               return 0;
+
+       ret = trace_seq_printf(s, "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n",
+                              SYSCALL_FIELD(int, nr));
+       if (!ret)
+               return 0;
 
        for (i = 0; i < entry->nb_args; i++) {
                ret = trace_seq_printf(s, "\tfield:%s %s;", entry->types[i],
                                        entry->args[i]);
                if (!ret)
                        return 0;
-               ret = trace_seq_printf(s, "\toffset:%d;\tsize:%lu;\n", offset,
+               ret = trace_seq_printf(s, "\toffset:%d;\tsize:%zu;\n", offset,
                                       sizeof(unsigned long));
                if (!ret)
                        return 0;
@@ -118,7 +131,7 @@ int ftrace_format_syscall(struct ftrace_event_call *call, struct trace_seq *s)
 
        trace_seq_printf(s, "\nprint fmt: \"");
        for (i = 0; i < entry->nb_args; i++) {
-               ret = trace_seq_printf(s, "%s: 0x%%0%lulx%s", entry->args[i],
+               ret = trace_seq_printf(s, "%s: 0x%%0%zulx%s", entry->args[i],
                                        sizeof(unsigned long),
                                        i == entry->nb_args - 1 ? "\", " : ", ");
                if (!ret)
@@ -287,16 +300,6 @@ struct trace_event event_syscall_exit = {
 
 #ifdef CONFIG_EVENT_PROFILE
 
-struct syscall_enter_record {
-       struct trace_entry      entry;
-       unsigned long           args[0];
-};
-
-struct syscall_exit_record {
-       struct trace_entry      entry;
-       unsigned long           ret;
-};
-
 static DECLARE_BITMAP(enabled_prof_enter_syscalls, FTRACE_SYSCALL_MAX);
 static DECLARE_BITMAP(enabled_prof_exit_syscalls, FTRACE_SYSCALL_MAX);
 static int sys_prof_refcount_enter;
@@ -304,7 +307,7 @@ static int sys_prof_refcount_exit;
 
 static void prof_syscall_enter(struct pt_regs *regs, long id)
 {
-       struct syscall_enter_record *rec;
+       struct syscall_trace_enter *rec;
        struct syscall_metadata *sys_data;
        int syscall_nr;
        int size;
@@ -328,9 +331,10 @@ static void prof_syscall_enter(struct pt_regs *regs, long id)
                /* zero the dead bytes from align to not leak stack to user */
                *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
 
-               rec = (struct syscall_enter_record *) raw_data;
-               tracing_generic_entry_update(&rec->entry, 0, 0);
-               rec->entry.type = sys_data->enter_id;
+               rec = (struct syscall_trace_enter *) raw_data;
+               tracing_generic_entry_update(&rec->ent, 0, 0);
+               rec->ent.type = sys_data->enter_id;
+               rec->nr = syscall_nr;
                syscall_get_arguments(current, regs, 0, sys_data->nb_args,
                                       (unsigned long *)&rec->args);
                perf_tpcounter_event(sys_data->enter_id, 0, 1, rec, size);
@@ -379,7 +383,7 @@ void unreg_prof_syscall_enter(char *name)
 static void prof_syscall_exit(struct pt_regs *regs, long ret)
 {
        struct syscall_metadata *sys_data;
-       struct syscall_exit_record rec;
+       struct syscall_trace_exit rec;
        int syscall_nr;
 
        syscall_nr = syscall_get_nr(current, regs);
@@ -390,8 +394,9 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret)
        if (!sys_data)
                return;
 
-       tracing_generic_entry_update(&rec.entry, 0, 0);
-       rec.entry.type = sys_data->exit_id;
+       tracing_generic_entry_update(&rec.ent, 0, 0);
+       rec.ent.type = sys_data->exit_id;
+       rec.nr = syscall_nr;
        rec.ret = syscall_get_return_value(current, regs);
 
        perf_tpcounter_event(sys_data->exit_id, 0, 1, &rec, sizeof(rec));