Delay setting linker soname until post-reloc and post-ctor

Setting the linker's soname ("ld-android.so") can allocate heap memory
now that the name uses an std::string, and it's probably a good idea to
defer doing this until after the linker has relocated itself (and after
it has called C++ constructors for global variables.)

Bug: none
Test: bionic unit tests
Test: verify that dlopen("ld-android.so", RTLD_NOLOAD) works
Change-Id: I6b9bd7552c3ae9b77e3ee9e2a98b069b8eef25ca

1 files changed, 7 insertions, 0 deletions

diff --git a/linker/linker_main.cpp b/linker/linker_main.cpp
index 59e803665..0b501a7b1 100644
--- a/linker/linker_main.cpp
+++ b/linker/linker_main.cpp
@@ -725,6 +725,13 @@ __linker_init_post_relocation(KernelArgumentBlock& args, soinfo& tmp_linker_so)
   // Initialize the linker's own global variables
   tmp_linker_so.call_constructors();
 
+  // Setting the linker soinfo's soname can allocate heap memory, so delay it until here.
+  for (const ElfW(Dyn)* d = tmp_linker_so.dynamic; d->d_tag != DT_NULL; ++d) {
+    if (d->d_tag == DT_SONAME) {
+      tmp_linker_so.set_soname(tmp_linker_so.get_string(d->d_un.d_val));
+    }
+  }
+
   // When the linker is run directly rather than acting as PT_INTERP, parse
   // arguments and determine the executable to load. When it's instead acting
   // as PT_INTERP, AT_ENTRY will refer to the loaded executable rather than the