AIX: base: Add Stack utilities

Port da409929

Original Commit Message:

    Adds:
    - GetStackStart
    - GetCurrentStackPosition
    - GetStackSlot which translates a stack slot through ASAN
      if needed

R=mlippautz@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Change-Id: Icdf50db1c4d0b6ce3c9819cda4663dc640ec6f43
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2144292Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Junliang Yan <jyan@ca.ibm.com>
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#67092}

src/base/platform/platform-aix.cc

@@ -129,5 +129,46 @@ void OS::SignalCodeMovingGC() {}
 
 void OS::AdjustSchedulingParams() {}
 
+// static
+void* Stack::GetStackStart() {
+  // Info about this subroutine can be found here:
+  // https://www.ibm.com/support/knowledgecenter/ssw_aix_72/p_bostechref/pthread_getthrds_np.html
+  // as well as the header file located under /usr/include/pthread.h in AIX.
+
+  // pthread_getthrds_np creates 3 values:
+  // __pi_stackaddr, __pi_stacksize, __pi_stackend
+  // __pi_stackend points to the higher address, stack base, since stack grows
+  // downwards.
+  // __pi_stackaddr points to the lower address, current sp location.
+  // __pi_stacksize is the size of the stack from the base in bytes.
+
+  // higher address   ----------------    __pi_stackend
+  //
+  //   |
+  //   |
+  //   |
+  //   |  __pi_stacksize, stack grows downwards
+  //   |
+  //   |
+  //   |
+  //   V
+  //
+  // lower address    ----------------    __pi_stackaddr
+
+  pthread_t tid = pthread_self();
+  struct __pthrdsinfo buf;
+  // clear buf
+  memset(&buf, 0, sizeof(buf));
+  char regbuf[1];
+  int regbufsize = sizeof(regbuf);
+  const int rc = pthread_getthrds_np(&tid, PTHRDSINFO_QUERY_ALL, &buf,
+                                     sizeof(buf), regbuf, &regbufsize);
+  CHECK(!rc);
+  if (buf.__pi_stackend == NULL || buf.__pi_stackaddr == NULL) {
+    return nullptr;
+  }
+  return reinterpret_cast<void*>(buf.__pi_stackend);
+}
+
 }  // namespace base
 }  // namespace v8

src/base/platform/platform-posix.cc

@@ -970,7 +970,7 @@ void Thread::SetThreadLocal(LocalStorageKey key, void* value) {
 // pthread_getattr_np used below is non portable (hence the _np suffix). We
 // keep this version in POSIX as most Linux-compatible derivatives will
 // support it. MacOS and FreeBSD are different here.
-#if !defined(V8_OS_FREEBSD) && !defined(V8_OS_MACOSX)
+#if !defined(V8_OS_FREEBSD) && !defined(V8_OS_MACOSX) && !defined(_AIX)
 
 // static
 void* Stack::GetStackStart() {
@@ -996,7 +996,7 @@ void* Stack::GetStackStart() {
   return nullptr;
 }
 
-#endif  // !defined(V8_OS_FREEBSD) && !defined(V8_OS_MACOSX)
+#endif  // !defined(V8_OS_FREEBSD) && !defined(V8_OS_MACOSX) && !defined(_AIX)
 
 // static
 void* Stack::GetCurrentStackPosition() { return __builtin_frame_address(0); }