Support detailed syscalls with 0 arguments

[deliverable/lttng-modules.git] / lttng-syscalls.c

diff --git a/lttng-syscalls.c b/lttng-syscalls.c
index 28348abe350a7e3de15f2d0824745d6a11e42963..09e48c4573c4727c11dba36e7f13c20366c45f41 100644 (file)
--- a/lttng-syscalls.c
+++ b/lttng-syscalls.c
@@ -17,6 +17,13 @@
 
 static void syscall_entry_probe(void *__data, struct pt_regs *regs, long id);
 
+/*
+ * Take care of NOARGS not supported by mainline.
+ */
+#define DECLARE_EVENT_CLASS_NOARGS(name, tstruct, assign, print)
+#define DEFINE_EVENT_NOARGS(template, name)
+#define TRACE_EVENT_NOARGS(name, struct, assign, print)
+
 /*
  * Create LTTng tracepoint probes.
  */
@@ -38,7 +45,7 @@ static void syscall_entry_probe(void *__data, struct pt_regs *regs, long id);
 
 struct trace_syscall_entry {
        void *func;
-       const struct lttng_event_desc *desc;    /* Set dynamically */
+       const struct lttng_event_desc *desc;
        const struct lttng_event_field *fields;
        unsigned int nrargs;
 };
@@ -48,11 +55,12 @@ static int sc_table_desc_filled;
 #define CREATE_SYSCALL_TABLE
 
 #undef TRACE_SYSCALL_TABLE
-#define TRACE_SYSCALL_TABLE(_name, _nr, _nrargs)               \
+#define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs)    \
        [ _nr ] = {                                             \
-               .func = __event_probe__##_name,                 \
+               .func = __event_probe__##_template,             \
                .nrargs = (_nrargs),                            \
-               .fields = __event_fields___##_name,             \
+               .fields = __event_fields___##_template,         \
+               .desc = &__event_desc___##_name,                \
        },
 
 static struct trace_syscall_entry sc_table[] = {
@@ -163,47 +171,12 @@ static void syscall_entry_probe(void *__data, struct pt_regs *regs, long id)
        }
 }
 
-static const struct lttng_event_desc *find_syscall_desc(unsigned int id)
-{
-       unsigned int i;
-
-       for (i = 0; i < __probe_desc___syscalls.nr_events; i++) {
-               if (__probe_desc___syscalls.event_desc[i].fields
-                               == sc_table[id].fields)
-                       return &__probe_desc___syscalls.event_desc[i];
-       }
-       WARN_ON_ONCE(1);
-       return NULL;
-}
-
-static void fill_sc_table_desc(void)
-{
-       unsigned int i;
-
-       if (sc_table_desc_filled)
-               return;
-       /*
-        * This is O(n^2), but rare. Eventually get the TRACE_EVENT code
-        * to emit per-event symbols to skip this.
-        */
-       for (i = 0; i < ARRAY_SIZE(sc_table); i++) {
-               const struct lttng_event_desc **desc = &sc_table[i].desc;
-
-               if (!sc_table[i].func)
-                       continue;
-               (*desc) = find_syscall_desc(i);
-       }
-       sc_table_desc_filled = 1;
-}
-
-
 int lttng_syscalls_register(struct ltt_channel *chan, void *filter)
 {
        unsigned int i;
        int ret;
 
        wrapper_vmalloc_sync_all();
-       fill_sc_table_desc();
 
        if (!chan->sc_table) {
                /* create syscall table mapping syscall to events */