libdl: Do not access the ELF file while the allocator is locked.

- Load symbols before allocation.
- Parse reloc records and place any reloc recs in a cache to use
  while the allocator is locked.
- Relocate symbols after section allocation.
- Split section loading into allocation/locating and loading.
- Update all arch back-ends with a new reloc interface to control
  tramp handling.
- Add `-a` and `-t` to the object list shell command.

Closes #3741

3 files changed, 52 insertions, 10 deletions

diff --git a/cpukit/include/rtems/rtl/rtl-obj.h b/cpukit/include/rtems/rtl/rtl-obj.h
index 9c2b4f0300..f27ae3259d 100644
--- a/cpukit/include/rtems/rtl/rtl-obj.h
+++ b/cpukit/include/rtems/rtl/rtl-obj.h
@@ -207,7 +207,7 @@ struct rtems_rtl_obj
   size_t              text_size;    /**< The size of the text section. */
   void*               const_base;   /**< The base address of the const section
                                      *   in memory. */
-  size_t              const_size;    /**< The size of the const section. */
+  size_t              const_size;   /**< The size of the const section. */
   void*               eh_base;      /**< The base address of the eh section in
                                      *   memory. */
   size_t              eh_size;      /**< The size of the eh section. */
@@ -227,10 +227,14 @@ struct rtems_rtl_obj
                                      *   obj. */
   void*               trampoline;   /**< Trampoline memory. Used for fixups or
                                      *   veneers */
-  size_t              tramp_size;   /**< Size of the tramopline memory. */
+  size_t              tramp_size;   /**< Size of a tramopline slot. */
+  size_t              tramps_size;  /**< Size of the trampoline memory. */
   void*               tramp_brk;    /**< Trampoline memory allocator. MD
                                      *   relocators can take memory from the
                                      *   break upto the size. */
+  size_t              tramp_relocs; /**< Number of slots reserved for
+                                     *   relocs. The remainder are for
+                                     *   unresolved symbols. */
   struct link_map*    linkmap;      /**< For GDB. */
   void*               loader;       /**< The file details specific to a
                                      *   loader. */
@@ -370,11 +374,35 @@ static inline bool rtems_rtl_obj_has_symbol (const rtems_rtl_obj*     obj,
  * @param size The size to be allocated.
  * @retval bool Returns @true if the space is available.
  */
-static inline bool rtems_rtl_obj_has_ramp_space (const rtems_rtl_obj* obj,
-                                                 const size_t         size)
+static inline bool rtems_rtl_obj_has_tramp_space (const rtems_rtl_obj* obj,
+                                                  const size_t         size)
 {
   return (obj->trampoline != NULL &&
-          ((obj->tramp_brk - obj->trampoline) + size) <= obj->tramp_size);
+          ((obj->tramp_brk - obj->trampoline) + size) <= obj->tramps_size);
+}
+
+/**
+ * Trampoline slots.
+ *
+ * @param obj The object file's descriptor.
+ * @retval size_t The number of trampoline slots.
+ */
+static inline size_t rtems_rtl_obj_trampoline_slots (const rtems_rtl_obj* obj)
+{
+  return obj->trampoline == NULL || obj->tramp_size == 0 ?
+    0 : obj->tramps_size / obj->tramp_size;
+}
+
+/**
+ * Number of trampolines.
+ *
+ * @param obj The object file's descriptor.
+ * @retval size_t The number of trampolines.
+ */
+static inline size_t rtems_rtl_obj_trampolines (const rtems_rtl_obj* obj)
+{
+  return obj->trampoline == NULL || obj->tramp_size == 0 ?
+    0 : (obj->tramp_brk - obj->trampoline) / obj->tramp_size;
 }
 
 /**
diff --git a/cpukit/include/rtems/rtl/rtl-unresolved.h b/cpukit/include/rtems/rtl/rtl-unresolved.h
index efc9ce220f..df07ecb1ba 100644
--- a/cpukit/include/rtems/rtl/rtl-unresolved.h
+++ b/cpukit/include/rtems/rtl/rtl-unresolved.h
@@ -1,5 +1,5 @@
 /*
- *  COPYRIGHT (c) 2012, 2018 Chris Johns <chrisj@rtems.org>
+ *  COPYRIGHT (c) 2012, 2019 Chris Johns <chrisj@rtems.org>
  *
  *  The license and distribution terms for this file may be
  *  found in the file LICENSE in this distribution or at
@@ -73,7 +73,8 @@ typedef enum rtems_rtl_unresolved_rtype
 {
   rtems_rtl_unresolved_empty = 0,  /**< The records is empty. Must always be 0 */
   rtems_rtl_unresolved_symbol = 1, /**< The record is a symbol. */
-  rtems_rtl_unresolved_reloc = 2   /**< The record is a relocation record. */
+  rtems_rtl_unresolved_reloc = 2,  /**< The record is a relocation record. */
+  rtems_rtl_trampoline_reloc = 3   /**< The record is a trampoline relocation record. */
 } rtems_rtl_unresolved_rtype;
 
 /**
@@ -101,7 +102,7 @@ typedef struct rtems_rtl_unresolv_symbol
 
 /**
  * Unresolved externals symbols require the relocation records to be held
- * and references.
+ * and referenced.
  */
 typedef struct rtems_rtl_unresolv_reloc
 {
@@ -113,6 +114,18 @@ typedef struct rtems_rtl_unresolv_reloc
 } rtems_rtl_unresolv_reloc;
 
 /**
+ * Trampolines require the relocation records to be held
+ */
+typedef struct rtems_rtl_tramp_reloc
+{
+  rtems_rtl_obj* obj;      /**< The relocation's object file. */
+  uint16_t       flags;    /**< Format specific flags. */
+  uint16_t       sect;     /**< The target section. */
+  rtems_rtl_word symvalue; /**< The symbol's value. */
+  rtems_rtl_word rel[3];   /**< Relocation record. */
+} rtems_rtl_tramp_reloc;
+
+/**
  * Unresolved externals records.
  */
 typedef struct rtems_rtl_unresolv_rec
@@ -121,7 +134,8 @@ typedef struct rtems_rtl_unresolv_rec
   union
   {
     rtems_rtl_unresolv_symbol name;   /**< The symbol, or */
-    rtems_rtl_unresolv_reloc  reloc;  /**< the relocation record. */
+    rtems_rtl_unresolv_reloc  reloc;  /**< The relocation record. */
+    rtems_rtl_tramp_reloc     tramp;  /**< The trampoline relocation record. */
   } rec;
 } rtems_rtl_unresolv_rec;
 
diff --git a/cpukit/include/rtems/rtl/rtl.h b/cpukit/include/rtems/rtl/rtl.h
index f13e33dbcb..67d7e96be3 100644
--- a/cpukit/include/rtems/rtl/rtl.h
+++ b/cpukit/include/rtems/rtl/rtl.h
@@ -72,7 +72,7 @@ extern "C" {
 /**
  * The number of relocation record per block in the unresolved table.
  */
-#define RTEMS_RTL_UNRESOLVED_BLOCK_SIZE (64)
+#define RTEMS_RTL_UNRESOLVED_BLOCK_SIZE (256)
 
 /**
  * The number of dependency record per block in the dependency table.