libdl: Manage the allocation of common uninitialised variables.

The use of separate text and data results in uninitialised variables
being placed in the common section. There is no section in ELF for
the common variables so the loader needs to create the section and
allocate the variables in that section. This patch does that.

The patch adds a second pass over the symbols.

The issue can also be seen as a section 65522 error.

Updates #3604

1 files changed, 46 insertions, 17 deletions

diff --git a/cpukit/libdl/rtl-obj.c b/cpukit/libdl/rtl-obj.c
index 45deccfb44..7109b86fe8 100644
--- a/cpukit/libdl/rtl-obj.c
+++ b/cpukit/libdl/rtl-obj.c
@@ -246,19 +246,6 @@ rtems_rtl_scan_decimal (const uint8_t* string, size_t len)
 }
 
 /**
- * Align the size to the next alignment point. Assume the alignment is a
- * positive integral power of 2 if not 0 or 1. If 0 or 1 then there is no
- * alignment.
- */
-static size_t
-rtems_rtl_sect_align (size_t offset, uint32_t alignment)
-{
-  if ((alignment > 1) && ((offset & (alignment - 1)) != 0))
-    offset = (offset + alignment) & ~(alignment - 1);
-  return offset;
-}
-
-/**
  * Section size summer iterator data.
  */
 typedef struct
@@ -274,7 +261,7 @@ rtems_rtl_obj_sect_summer (rtems_chain_node* node, void* data)
   rtems_rtl_obj_sect_summer_data* summer = data;
   if ((sect->flags & summer->mask) == summer->mask)
     summer->size =
-      rtems_rtl_sect_align (summer->size, sect->alignment) + sect->size;
+      rtems_rtl_obj_align (summer->size, sect->alignment) + sect->size;
   return true;
 }
 
@@ -438,9 +425,9 @@ rtems_rtl_obj_add_section (rtems_rtl_obj* obj,
     rtems_chain_append (&obj->sections, &sect->node);
 
     if (rtems_rtl_trace (RTEMS_RTL_TRACE_SECTION))
-      printf ("rtl: sect: %-2d: %s (%zu)\n", section, name, size);
+      printf ("rtl: sect: add: %-2d: %s (%zu) 0x%08lx\n",
+              section, name, size, flags);
   }
-
   return true;
 }
 
@@ -467,6 +454,8 @@ typedef struct
   rtems_rtl_obj_sect*  sect;  /**< The matching section. */
   const char*          name;  /**< The name to match. */
   int                  index; /**< The index to match. */
+  uint32_t             mask;  /**< The mask to match. */
+  unsigned int         flags; /**< The flags to use when matching. */
 } rtems_rtl_obj_sect_finder;
 
 static bool
@@ -489,6 +478,8 @@ rtems_rtl_obj_find_section (const rtems_rtl_obj* obj,
   rtems_rtl_obj_sect_finder match;
   match.sect = NULL;
   match.name = name;
+  match.mask = 0;
+  match.flags = 0;
   rtems_rtl_chain_iterate ((rtems_chain_control*) &obj->sections,
                            rtems_rtl_obj_sect_match_name,
                            &match);
@@ -515,12 +506,50 @@ rtems_rtl_obj_find_section_by_index (const rtems_rtl_obj* obj,
   rtems_rtl_obj_sect_finder match;
   match.sect = NULL;
   match.index = index;
+  match.mask = 0;
+  match.flags = 0;
   rtems_rtl_chain_iterate ((rtems_chain_control*) &obj->sections,
                            rtems_rtl_obj_sect_match_index,
                            &match);
   return match.sect;
 }
 
+static bool
+rtems_rtl_obj_sect_match_mask (rtems_chain_node* node, void* data)
+{
+  rtems_rtl_obj_sect*        sect = (rtems_rtl_obj_sect*) node;
+  rtems_rtl_obj_sect_finder* match = data;
+  if (match->flags == 0)
+  {
+    if (match->index < 0 || sect->section == match->index)
+      match->flags = 1;
+    if (match->index >= 0)
+      return true;
+  }
+  if ((sect->flags & match->mask) != 0)
+  {
+    match->sect = sect;
+    return false;
+  }
+  return true;
+}
+
+rtems_rtl_obj_sect*
+rtems_rtl_obj_find_section_by_mask (const rtems_rtl_obj* obj,
+                                    int                  index,
+                                    uint32_t             mask)
+{
+  rtems_rtl_obj_sect_finder match;
+  match.sect = NULL;
+  match.index = index;
+  match.mask = mask;
+  match.flags = 0;
+  rtems_rtl_chain_iterate ((rtems_chain_control*) &obj->sections,
+                           rtems_rtl_obj_sect_match_mask,
+                           &match);
+  return match.sect;
+}
+
 size_t
 rtems_rtl_obj_text_size (const rtems_rtl_obj* obj)
 {
@@ -775,7 +804,7 @@ rtems_rtl_obj_sections_loader (uint32_t                   mask,
       if (sect->load_order == order)
       {
         if (!first)
-          base_offset = rtems_rtl_sect_align (base_offset, sect->alignment);
+          base_offset = rtems_rtl_obj_align (base_offset, sect->alignment);
 
         first = false;