diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp
--- a/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp
@@ -482,9 +482,12 @@
 typedef user_regs_struct regs_struct;
 #if defined(__i386__)
 #define REG_SP esp
+static constexpr uptr kExtraRegs[] = {NT_X86_XSTATE, NT_PRFPXREG};
 #else
 #define REG_SP rsp
+static constexpr uptr kExtraRegs[] = {NT_X86_XSTATE, NT_FPREGSET};
 #endif
+#define ARCH_IOVEC_FOR_GETREGSET
 
 #elif defined(__powerpc__) || defined(__powerpc64__)
 typedef pt_regs regs_struct;
@@ -501,11 +504,13 @@
 #elif defined(__aarch64__)
 typedef struct user_pt_regs regs_struct;
 #define REG_SP sp
+static constexpr uptr kExtraRegs[] = {};
 #define ARCH_IOVEC_FOR_GETREGSET
 
 #elif defined(__s390__)
 typedef _user_regs_struct regs_struct;
 #define REG_SP gprs[15]
+static constexpr uptr kExtraRegs[] = {};
 #define ARCH_IOVEC_FOR_GETREGSET
 
 #else
@@ -532,25 +537,53 @@
   thread_ids_.push_back(tid);
 }
 
+static bool AppendRegisters(pid_t tid, uptr regset,
+                            InternalMmapVector<uptr> *buffer, int *pterrno) {
+  struct iovec regset_io;
+  uptr size = buffer->size();
+  for (;; buffer->resize(buffer->capacity() * 2)) {
+    buffer->resize(buffer->capacity());
+    regset_io.iov_base = buffer->data() + size;
+    regset_io.iov_len = (buffer->size() - size) * sizeof(uptr);
+    bool isErr =
+        internal_iserror(internal_ptrace(PTRACE_GETREGSET, tid, (void *)regset,
+                                         (void *)&regset_io),
+                         pterrno);
+    if (isErr) {
+      buffer->resize(size);
+      return false;
+    }
+
+    // Far enough from the buffer size, no need to resize and repeat.
+    if (regset_io.iov_len + 64 < buffer->size() * sizeof(uptr))
+      break;
+  }
+  buffer->resize(RoundUpTo(regset_io.iov_len, sizeof(uptr)) / sizeof(uptr));
+  return true;
+}
+
 PtraceRegistersStatus SuspendedThreadsListLinux::GetRegistersAndSP(
     uptr index, InternalMmapVector<uptr> *buffer, uptr *sp) const {
   pid_t tid = GetThreadID(index);
-  regs_struct regs;
   int pterrno;
 #ifdef ARCH_IOVEC_FOR_GETREGSET
-  struct iovec regset_io;
-  regset_io.iov_base = &regs;
-  regset_io.iov_len = sizeof(regs_struct);
-  bool isErr = internal_iserror(internal_ptrace(PTRACE_GETREGSET, tid,
-                                (void*)NT_PRSTATUS, (void*)&regset_io),
-                                &pterrno);
+  buffer->clear();
+  buffer->reserve(Max<uptr>(1024, buffer->capacity()));
+  bool isErr = !AppendRegisters(tid, NT_PRSTATUS, buffer, &pterrno);
+  if (!isErr) {
+    // Accept the first available and do not report errors.
+    for (uptr regs : kExtraRegs)
+      if (AppendRegisters(tid, regs, buffer, &pterrno))
+        break;
+  }
 #else
-  bool isErr = internal_iserror(internal_ptrace(PTRACE_GETREGS, tid, nullptr,
-                                &regs), &pterrno);
+  buffer->resize(RoundUpTo(sizeof(regs_struct), sizeof(uptr)) / sizeof(uptr));
+  bool isErr = internal_iserror(
+      internal_ptrace(PTRACE_GETREGS, tid, nullptr, buffer->data()), &pterrno);
 #endif
   if (isErr) {
-    VReport(1, "Could not get registers from thread %d (errno %d).\n", tid,
-            pterrno);
+    Report("Could not get registers from thread %d (errno %d).\n", tid,
+           pterrno);
     // ESRCH means that the given thread is not suspended or already dead.
     // Therefore it's unsafe to inspect its data (e.g. walk through stack) and
     // we should notify caller about this.
@@ -558,9 +591,7 @@
                             : REGISTERS_UNAVAILABLE;
   }
 
-  *sp = regs.REG_SP;
-  buffer->resize(RoundUpTo(sizeof(regs), sizeof(uptr)) / sizeof(uptr));
-  internal_memcpy(buffer->data(), &regs, sizeof(regs));
+  *sp = reinterpret_cast<regs_struct *>(buffer->data())[0].REG_SP;
   return REGISTERS_AVAILABLE;
 }