linker: changes to init work arounds

Change three things regarding the work around to the fact that init is
special:

1) Only first stage init is special, so we change the check to include
   accessing /proc/self/exe, which if is available, means that we're
   not first stage init and do not need any work arounds.
2) Fix the fact that /init may be a symlink and may need readlink()
3) Suppress errors from realpath_fd() since these are expected to fail
   due to /proc not being mounted.

Bug: 80395578
Test: sailfish boots without the audit generated from calling stat()
      on /init and without the errors from realpath_fd()

Change-Id: I266f1486b142cb9a41ec791eba74122bdf38cf12

1 files changed, 2 insertions, 2 deletions

diff --git a/linker/linker_utils.cpp b/linker/linker_utils.cpp
index 6b9aec9fa..72a8fa8fe 100644
--- a/linker/linker_utils.cpp
+++ b/linker/linker_utils.cpp
@@ -240,7 +240,7 @@ void resolve_paths(std::vector<std::string>& paths,
   }
 }
 
-bool is_init() {
-  static bool ret = (getpid() == 1);
+bool is_first_stage_init() {
+  static bool ret = (getpid() == 1 && access("/proc/self/exe", F_OK) == -1);
   return ret;
 }