SoW-2019-0002: Dynamic Snapshot

[lttng-tools.git] / src / common / userspace-probe.c

diff --git a/src/common/userspace-probe.c b/src/common/userspace-probe.c
index 508c9e8d4480a8a99216e7a3792a6555dd534d3f..4cc881025656cb582ffbcbf701051539ed564809 100644 (file)
--- a/src/common/userspace-probe.c
+++ b/src/common/userspace-probe.c
@@ -144,6 +144,41 @@ void lttng_userspace_probe_location_destroy(
        }
 }
 
+static
+bool lttng_userspace_probe_location_function_is_equal(const struct lttng_userspace_probe_location *_a,
+               const struct lttng_userspace_probe_location *_b)
+{
+       bool is_equal = false;
+       struct lttng_userspace_probe_location_function *a, *b;
+
+       a = container_of(_a, struct lttng_userspace_probe_location_function, parent);
+       b = container_of(_b, struct lttng_userspace_probe_location_function, parent);
+
+       /* The binary_fd is not checked since it does not hold "immutable"
+        * information.
+        */
+
+       if (a->instrumentation_type != b->instrumentation_type) {
+               goto end;
+       }
+
+       assert(a->function_name);
+       assert(b->function_name);
+       if (strcmp(a->function_name, b->function_name)) {
+               goto end;
+       }
+
+       assert(a->binary_path);
+       assert(b->binary_path);
+       if (strcmp(a->binary_path, b->binary_path)) {
+               goto end;
+       }
+
+       is_equal = true;
+end:
+       return is_equal;
+}
+
 static struct lttng_userspace_probe_location *
 lttng_userspace_probe_location_function_create_no_check(const char *binary_path,
                const char *function_name,
@@ -192,6 +227,7 @@ lttng_userspace_probe_location_function_create_no_check(const char *binary_path,
        ret = &location->parent;
        ret->lookup_method = lookup_method;
        ret->type = LTTNG_USERSPACE_PROBE_LOCATION_TYPE_FUNCTION;
+       ret->equal = lttng_userspace_probe_location_function_is_equal;
        goto end;
 
 error:
@@ -206,6 +242,43 @@ end:
        return ret;
 }
 
+static
+bool lttng_userspace_probe_location_tracepoint_is_equal(const struct lttng_userspace_probe_location *_a,
+               const struct lttng_userspace_probe_location *_b)
+{
+       bool is_equal = false;
+       struct lttng_userspace_probe_location_tracepoint *a, *b;
+
+       a = container_of(_a, struct lttng_userspace_probe_location_tracepoint, parent);
+       b = container_of(_b, struct lttng_userspace_probe_location_tracepoint, parent);
+
+       /* The binary_fd is not checked since it does not hold "immutable"
+        * information.
+        */
+
+       assert(a->probe_name);
+       assert(b->probe_name);
+       if (strcmp(a->probe_name, b->probe_name)) {
+               goto end;
+       }
+
+       assert(a->provider_name);
+       assert(b->provider_name);
+       if (strcmp(a->provider_name, b->provider_name)) {
+               goto end;
+       }
+
+       assert(a->binary_path);
+       assert(b->binary_path);
+       if (strcmp(a->binary_path, b->binary_path)) {
+               goto end;
+       }
+
+       is_equal = true;
+end:
+       return is_equal;
+}
+
 static struct lttng_userspace_probe_location *
 lttng_userspace_probe_location_tracepoint_create_no_check(const char *binary_path,
                const char *provider_name, const char *probe_name,
@@ -261,6 +334,7 @@ lttng_userspace_probe_location_tracepoint_create_no_check(const char *binary_pat
        ret = &location->parent;
        ret->lookup_method = lookup_method;
        ret->type = LTTNG_USERSPACE_PROBE_LOCATION_TYPE_TRACEPOINT;
+       ret->equal = lttng_userspace_probe_location_tracepoint_is_equal;
        goto end;
 
 error:
@@ -1711,3 +1785,70 @@ struct lttng_userspace_probe_location *lttng_userspace_probe_location_copy(
 err:
        return new_location;
 }
+
+LTTNG_HIDDEN
+bool lttng_userspace_probe_location_is_equal(
+               const struct lttng_userspace_probe_location *a,
+               const struct lttng_userspace_probe_location *b)
+{
+       bool is_equal = false;
+
+       if (!a || !b) {
+               goto end;
+       }
+
+       if (a->type != b->type) {
+               goto end;
+       }
+
+       if (a == b) {
+               is_equal = true;
+               goto end;
+       }
+
+       is_equal = a->equal ? a->equal(a, b) : true;
+end:
+       return is_equal;
+}
+
+LTTNG_HIDDEN
+int lttng_userspace_probe_location_set_binary_fd(
+               struct lttng_userspace_probe_location *location, int fd)
+{
+       int ret = 0;
+       const struct lttng_userspace_probe_location_lookup_method *lookup = NULL;
+       /*
+        * Set the file descriptor received from the client through the unix
+        * socket in the probe location.
+        */
+       lookup = lttng_userspace_probe_location_get_lookup_method(location);
+       if (!lookup) {
+               ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
+               goto end;
+       }
+
+       /*
+        * From the kernel tracer's perspective, all userspace probe event types
+        * are all the same: a file and an offset.
+        */
+       switch (lttng_userspace_probe_location_lookup_method_get_type(lookup)) {
+       case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF:
+               ret = lttng_userspace_probe_location_function_set_binary_fd(
+                               location, fd);
+               break;
+       case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT:
+               ret = lttng_userspace_probe_location_tracepoint_set_binary_fd(
+                               location, fd);
+               break;
+       default:
+               ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
+               goto end;
+       }
+
+       if (ret) {
+               ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
+               goto end;
+       }
+end:
+       return ret;
+}