1 files changed, 59 insertions, 54 deletions

diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 75289f372dd2..a1834dda85f4 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -143,70 +143,65 @@ extern char *__bad_type_size(void);
                 #type, #name, offsetof(typeof(trace), name),            \
                 sizeof(trace.name), is_signed_type(type)
 
-int syscall_enter_format(struct ftrace_event_call *call, struct trace_seq *s)
+static
+int  __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len)
 {
         int i;
-        int ret;
-        struct syscall_metadata *entry = call->data;
-        struct syscall_trace_enter trace;
-        int offset = offsetof(struct syscall_trace_enter, args);
+        int pos = 0;
 
-        ret = trace_seq_printf(s, "\tfield:%s %s;\toffset:%zu;\tsize:%zu;"
-                               "\tsigned:%u;\n",
-                               SYSCALL_FIELD(int, nr));
-        if (!ret)
-                return 0;
+        /* When len=0, we just calculate the needed length */
+#define LEN_OR_ZERO (len ? len - pos : 0)
 
+        pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
         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:%zu;"
-                                       "\tsigned:%u;\n", offset,
-                                       sizeof(unsigned long),
-                                       is_signed_type(unsigned long));
-                if (!ret)
-                        return 0;
-                offset += sizeof(unsigned long);
+                pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s",
+                                entry->args[i], sizeof(unsigned long),
+                                i == entry->nb_args - 1 ? "" : ", ");
         }
+        pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
 
-        trace_seq_puts(s, "\nprint fmt: \"");
         for (i = 0; i < entry->nb_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)
-                        return 0;
+                pos += snprintf(buf + pos, LEN_OR_ZERO,
+                                ", ((unsigned long)(REC->%s))", entry->args[i]);
         }
-        trace_seq_putc(s, '"');
 
-        for (i = 0; i < entry->nb_args; i++) {
-                ret = trace_seq_printf(s, ", ((unsigned long)(REC->%s))",
-                                       entry->args[i]);
-                if (!ret)
-                        return 0;
-        }
+#undef LEN_OR_ZERO
 
-        return trace_seq_putc(s, '\n');
+        /* return the length of print_fmt */
+        return pos;
 }
 
-int syscall_exit_format(struct ftrace_event_call *call, struct trace_seq *s)
+static int set_syscall_print_fmt(struct ftrace_event_call *call)
 {
-        int ret;
-        struct syscall_trace_exit trace;
+        char *print_fmt;
+        int len;
+        struct syscall_metadata *entry = call->data;
 
-        ret = trace_seq_printf(s,
-                               "\tfield:%s %s;\toffset:%zu;\tsize:%zu;"
-                               "\tsigned:%u;\n"
-                               "\tfield:%s %s;\toffset:%zu;\tsize:%zu;"
-                               "\tsigned:%u;\n",
-                               SYSCALL_FIELD(int, nr),
-                               SYSCALL_FIELD(long, ret));
-        if (!ret)
+        if (entry->enter_event != call) {
+                call->print_fmt = "\"0x%lx\", REC->ret";
                 return 0;
+        }
 
-        return trace_seq_printf(s, "\nprint fmt: \"0x%%lx\", REC->ret\n");
+        /* First: called with 0 length to calculate the needed length */
+        len = __set_enter_print_fmt(entry, NULL, 0);
+
+        print_fmt = kmalloc(len + 1, GFP_KERNEL);
+        if (!print_fmt)
+                return -ENOMEM;
+
+        /* Second: actually write the @print_fmt */
+        __set_enter_print_fmt(entry, print_fmt, len + 1);
+        call->print_fmt = print_fmt;
+
+        return 0;
+}
+
+static void free_syscall_print_fmt(struct ftrace_event_call *call)
+{
+        struct syscall_metadata *entry = call->data;
+
+        if (entry->enter_event == call)
+                kfree(call->print_fmt);
 }
 
 int syscall_enter_define_fields(struct ftrace_event_call *call)
@@ -386,12 +381,22 @@ int init_syscall_trace(struct ftrace_event_call *call)
 {
         int id;
 
-        id = register_ftrace_event(call->event);
-        if (!id)
-                return -ENODEV;
-        call->id = id;
-        INIT_LIST_HEAD(&call->fields);
-        return 0;
+        if (set_syscall_print_fmt(call) < 0)
+                return -ENOMEM;
+
+        id = trace_event_raw_init(call);
+
+        if (id < 0) {
+                free_syscall_print_fmt(call);
+                return id;
+        }
+
+        return id;
+}
+
+unsigned long __init arch_syscall_addr(int nr)
+{
+        return (unsigned long)sys_call_table[nr];
 }
 
 int __init init_ftrace_syscalls(void)
@@ -603,7 +608,7 @@ int prof_sysexit_enable(struct ftrace_event_call *call)
                 ret = register_trace_sys_exit(prof_syscall_exit);
         if (ret) {
                 pr_info("event trace: Could not activate"
-                                "syscall entry trace point");
+                                "syscall exit trace point");
         } else {
                 set_bit(num, enabled_prof_exit_syscalls);
                 sys_prof_refcount_exit++;