X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=libringbuffer%2Fshm.h;h=e8fc8d70384910139306e0d2d0fbcfc41cbcb615;hb=4318ae1be57eb7983ab4857a7a8eeb4a030a8216;hp=9f72a5a248657f73c3176877d2e6357930dd10db;hpb=cba4b7a3bf98faff4c905f71064f7d66b9869e79;p=lttng-ust.git

diff --git a/libringbuffer/shm.h b/libringbuffer/shm.h
index 9f72a5a2..e8fc8d70 100644
--- a/libringbuffer/shm.h
+++ b/libringbuffer/shm.h
@@ -10,13 +10,18 @@
  */
 
 #include <stdint.h>
-#include <ust/usterr-signal-safe.h>
-#include "ust/core.h"
+#include <lttng/usterr-signal-safe.h>
+#include "lttng/core.h"
 #include "shm_types.h"
 
 /*
  * Pointer dereferencing. We don't trust the shm_ref, so we validate
  * both the index and offset with known boundaries.
+ *
+ * "shmp" and "shmp_index" guarantee that it's safe to use the pointer
+ * target type, even in the occurrence of shm_ref modification by an
+ * untrusted process having write access to the shm_ref. We return a
+ * NULL pointer if the ranges are invalid.
  */
 static inline
 char *_shmp_offset(struct shm_object_table *table, struct shm_ref *ref,
@@ -26,13 +31,13 @@ char *_shmp_offset(struct shm_object_table *table, struct shm_ref *ref,
 	size_t objindex, ref_offset;
 
 	objindex = (size_t) ref->index;
-	if (unlikely(objindex >= table->allocated_len))
+	if (caa_unlikely(objindex >= table->allocated_len))
 		return NULL;
 	obj = &table->objects[objindex];
 	ref_offset = (size_t) ref->offset;
 	ref_offset += idx * elem_size;
 	/* Check if part of the element returned would exceed the limits. */
-	if (unlikely(ref_offset + elem_size > obj->memory_map_size))
+	if (caa_unlikely(ref_offset + elem_size > obj->memory_map_size))
 		return NULL;
 	return &obj->memory_map[ref_offset];
 }
@@ -55,6 +60,8 @@ void _set_shmp(struct shm_ref *ref, struct shm_ref src)
 #define set_shmp(ref, src)	_set_shmp(&(ref)._ref, src)
 
 struct shm_object_table *shm_object_table_create(size_t max_nb_obj);
+struct shm_object *shm_object_table_append_shadow(struct shm_object_table *table,
+			int shm_fd, int wait_fd, size_t memory_map_size);
 void shm_object_table_destroy(struct shm_object_table *table);
 struct shm_object *shm_object_table_append(struct shm_object_table *table,
 					   size_t memory_map_size);
@@ -70,14 +77,14 @@ struct shm_ref zalloc_shm(struct shm_object *obj, size_t len);
 void align_shm(struct shm_object *obj, size_t align);
 
 static inline
-int shm_get_wakeup_fd(struct shm_handle *handle, struct shm_ref *ref)
+int shm_get_wakeup_fd(struct lttng_ust_shm_handle *handle, struct shm_ref *ref)
 {
 	struct shm_object_table *table = handle->table;
 	struct shm_object *obj;
 	size_t index;
 
 	index = (size_t) ref->index;
-	if (unlikely(index >= table->allocated_len))
+	if (caa_unlikely(index >= table->allocated_len))
 		return -EPERM;
 	obj = &table->objects[index];
 	return obj->wait_fd[1];
@@ -85,17 +92,35 @@ int shm_get_wakeup_fd(struct shm_handle *handle, struct shm_ref *ref)
 }
 
 static inline
-int shm_get_wait_fd(struct shm_handle *handle, struct shm_ref *ref)
+int shm_get_wait_fd(struct lttng_ust_shm_handle *handle, struct shm_ref *ref)
 {
 	struct shm_object_table *table = handle->table;
 	struct shm_object *obj;
 	size_t index;
 
 	index = (size_t) ref->index;
-	if (unlikely(index >= table->allocated_len))
+	if (caa_unlikely(index >= table->allocated_len))
 		return -EPERM;
 	obj = &table->objects[index];
 	return obj->wait_fd[0];
 }
 
+static inline
+int shm_get_object_data(struct lttng_ust_shm_handle *handle, struct shm_ref *ref,
+		int *shm_fd, int *wait_fd, uint64_t *memory_map_size)
+{
+	struct shm_object_table *table = handle->table;
+	struct shm_object *obj;
+	size_t index;
+
+	index = (size_t) ref->index;
+	if (caa_unlikely(index >= table->allocated_len))
+		return -EPERM;
+	obj = &table->objects[index];
+	*shm_fd = obj->shm_fd;
+	*wait_fd = obj->wait_fd[0];
+	*memory_map_size = obj->allocated_len;
+	return 0;
+}
+
 #endif /* _LIBRINGBUFFER_SHM_H */