libdl/alloc: Add a locking interface to the allocator.

- Allow an allocator to lock the allocations. This is needed to
  lock the heap allocator so the text and trampoline table are
  as close together as possible to allow for the largest possible
  object file size.

- Update the default heap allocator to lock the heap allocator.

- Update ELF loading to lock the allocator.

Updates #3685

1 files changed, 11 insertions, 0 deletions

diff --git a/cpukit/libdl/rtl-elf.c b/cpukit/libdl/rtl-elf.c
index 54ea1464cc..963cb4b2f4 100644
--- a/cpukit/libdl/rtl-elf.c
+++ b/cpukit/libdl/rtl-elf.c
@@ -1457,6 +1457,12 @@ rtems_rtl_elf_file_load (rtems_rtl_obj* obj, int fd)
   obj->entry = (void*)(uintptr_t) ehdr.e_entry;
 
   /*
+   * Lock the allocator so the section memory and the trampoline memory are as
+   * clock as possible.
+   */
+  rtems_rtl_alloc_lock ();
+
+  /*
    * Allocate the sections.
    */
   if (!rtems_rtl_obj_alloc_sections (obj, fd, rtems_rtl_elf_arch_alloc, &ehdr))
@@ -1481,6 +1487,11 @@ rtems_rtl_elf_file_load (rtems_rtl_obj* obj, int fd)
   if (!rtems_rtl_elf_alloc_trampoline (obj, relocs.unresolved))
     return false;
 
+  /*
+   * Unlock the allocator.
+   */
+  rtems_rtl_alloc_unlock ();
+
   if (!rtems_rtl_obj_load_symbols (obj, fd, rtems_rtl_elf_symbols, &ehdr))
     return false;