1 files changed, 71 insertions, 118 deletions

diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 75289f372dd2..cba47d7935cc 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;
+        }
+
+        /* 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 trace_seq_printf(s, "\nprint fmt: \"0x%%lx\", REC->ret\n");
+        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)
@@ -421,7 +426,7 @@ int __init init_ftrace_syscalls(void)
 }
 core_initcall(init_ftrace_syscalls);
 
-#ifdef CONFIG_EVENT_PROFILE
+#ifdef CONFIG_PERF_EVENTS
 
 static DECLARE_BITMAP(enabled_prof_enter_syscalls, NR_syscalls);
 static DECLARE_BITMAP(enabled_prof_exit_syscalls, NR_syscalls);
@@ -433,12 +438,9 @@ static void prof_syscall_enter(struct pt_regs *regs, long id)
         struct syscall_metadata *sys_data;
         struct syscall_trace_enter *rec;
         unsigned long flags;
-        char *trace_buf;
-        char *raw_data;
         int syscall_nr;
         int rctx;
         int size;
-        int cpu;
 
         syscall_nr = syscall_get_nr(current, regs);
         if (!test_bit(syscall_nr, enabled_prof_enter_syscalls))
@@ -457,37 +459,15 @@ static void prof_syscall_enter(struct pt_regs *regs, long id)
                       "profile buffer not large enough"))
                 return;
 
-        /* Protect the per cpu buffer, begin the rcu read side */
-        local_irq_save(flags);
-
-        rctx = perf_swevent_get_recursion_context();
-        if (rctx < 0)
-                goto end_recursion;
-
-        cpu = smp_processor_id();
-
-        trace_buf = rcu_dereference(perf_trace_buf);
-
-        if (!trace_buf)
-                goto end;
-
-        raw_data = per_cpu_ptr(trace_buf, cpu);
-
-        /* zero the dead bytes from align to not leak stack to user */
-        *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+        rec = (struct syscall_trace_enter *)ftrace_perf_buf_prepare(size,
+                                sys_data->enter_event->id, &rctx, &flags);
+        if (!rec)
+                return;
 
-        rec = (struct syscall_trace_enter *) raw_data;
-        tracing_generic_entry_update(&rec->ent, 0, 0);
-        rec->ent.type = sys_data->enter_event->id;
         rec->nr = syscall_nr;
         syscall_get_arguments(current, regs, 0, sys_data->nb_args,
                                (unsigned long *)&rec->args);
-        perf_tp_event(sys_data->enter_event->id, 0, 1, rec, size);
-
-end:
-        perf_swevent_put_recursion_context(rctx);
-end_recursion:
-        local_irq_restore(flags);
+        ftrace_perf_buf_submit(rec, size, rctx, 0, 1, flags);
 }
 
 int prof_sysenter_enable(struct ftrace_event_call *call)
@@ -531,11 +511,8 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret)
         struct syscall_trace_exit *rec;
         unsigned long flags;
         int syscall_nr;
-        char *trace_buf;
-        char *raw_data;
         int rctx;
         int size;
-        int cpu;
 
         syscall_nr = syscall_get_nr(current, regs);
         if (!test_bit(syscall_nr, enabled_prof_exit_syscalls))
@@ -557,38 +534,15 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret)
                 "exit event has grown above profile buffer size"))
                 return;
 
-        /* Protect the per cpu buffer, begin the rcu read side */
-        local_irq_save(flags);
-
-        rctx = perf_swevent_get_recursion_context();
-        if (rctx < 0)
-                goto end_recursion;
-
-        cpu = smp_processor_id();
-
-        trace_buf = rcu_dereference(perf_trace_buf);
-
-        if (!trace_buf)
-                goto end;
-
-        raw_data = per_cpu_ptr(trace_buf, cpu);
-
-        /* zero the dead bytes from align to not leak stack to user */
-        *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
-
-        rec = (struct syscall_trace_exit *)raw_data;
+        rec = (struct syscall_trace_exit *)ftrace_perf_buf_prepare(size,
+                                sys_data->exit_event->id, &rctx, &flags);
+        if (!rec)
+                return;
 
-        tracing_generic_entry_update(&rec->ent, 0, 0);
-        rec->ent.type = sys_data->exit_event->id;
         rec->nr = syscall_nr;
         rec->ret = syscall_get_return_value(current, regs);
 
-        perf_tp_event(sys_data->exit_event->id, 0, 1, rec, size);
-
-end:
-        perf_swevent_put_recursion_context(rctx);
-end_recursion:
-        local_irq_restore(flags);
+        ftrace_perf_buf_submit(rec, size, rctx, 0, 1, flags);
 }
 
 int prof_sysexit_enable(struct ftrace_event_call *call)
@@ -603,7 +557,7 @@ 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++;
@@ -626,6 +580,5 @@ void prof_sysexit_disable(struct ftrace_event_call *call)
         mutex_unlock(&syscall_trace_lock);
 }
 
-#endif
-
+#endif /* CONFIG_PERF_EVENTS */