Backport 1bfb57dca4a65ea64a15914b1e8b5c4c509db6f5

Author: duke

src/hotspot/os_cpu/linux_x86/os_linux_x86.cpp

@@ -560,6 +560,21 @@ void os::print_context(outputStream *st, const void *context) {
   st->print(", ERR=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_ERR]);
   st->cr();
   st->print("  TRAPNO=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_TRAPNO]);
+  // Add XMM registers + MXCSR. Note that C2 uses XMM to spill GPR values including pointers.
+  st->cr();
+  st->cr();
+  // Sanity check: fpregs should point into the context.
+  if ((address)uc->uc_mcontext.fpregs < (address)uc ||
+      pointer_delta(uc->uc_mcontext.fpregs, uc, 1) >= sizeof(ucontext_t)) {
+    st->print_cr("bad uc->uc_mcontext.fpregs: " INTPTR_FORMAT " (uc: " INTPTR_FORMAT ")",
+                 p2i(uc->uc_mcontext.fpregs), p2i(uc));
+  } else {
+    for (int i = 0; i < 16; ++i) {
+      const int64_t* xmm_val_addr = (int64_t*)&(uc->uc_mcontext.fpregs->_xmm[i]);
+      st->print_cr("XMM[%d]=" INTPTR_FORMAT " " INTPTR_FORMAT, i, xmm_val_addr[1], xmm_val_addr[0]);
+    }
+    st->print("  MXCSR=" UINT32_FORMAT_X_0, uc->uc_mcontext.fpregs->mxcsr);
+  }
 #else
   st->print(  "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EAX]);
   st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBX]);

src/hotspot/os_cpu/windows_x86/os_windows_x86.cpp

@@ -432,6 +432,15 @@ void os::print_context(outputStream *st, const void *context) {
   st->cr();
   st->print(  "RIP=" INTPTR_FORMAT, uc->Rip);
   st->print(", EFLAGS=" INTPTR_FORMAT, uc->EFlags);
+  // Add XMM registers + MXCSR. Note that C2 uses XMM to spill GPR values including pointers.
+  st->cr();
+  st->cr();
+  for (int i = 0; i < 16; ++i) {
+    const uint64_t *xmm = ((const uint64_t*)&(uc->Xmm0)) + 2 * i;
+    st->print_cr("XMM[%d]=" INTPTR_FORMAT " " INTPTR_FORMAT,
+                 i, xmm[1], xmm[0]);
+  }
+  st->print("  MXCSR=" UINT32_FORMAT_X_0, uc->MxCsr);
 #else
   st->print(  "EAX=" INTPTR_FORMAT, uc->Eax);
   st->print(", EBX=" INTPTR_FORMAT, uc->Ebx);

src/hotspot/share/utilities/debug.cpp

@@ -743,10 +743,22 @@ void disarm_assert_poison() {
 
 static void store_context(const void* context) {
   memcpy(&g_stored_assertion_context, context, sizeof(ucontext_t));
-#if defined(LINUX) && defined(PPC64)
+#if defined(LINUX)
   // on Linux ppc64, ucontext_t contains pointers into itself which have to be patched up
   //  after copying the context (see comment in sys/ucontext.h):
+#if defined(PPC64)
   *((void**) &g_stored_assertion_context.uc_mcontext.regs) = &(g_stored_assertion_context.uc_mcontext.gp_regs);
+#elif defined(AMD64)
+  // In the copied version, fpregs should point to the copied contents.
+  // Sanity check: fpregs should point into the context.
+  if ((address)((const ucontext_t*)context)->uc_mcontext.fpregs > (address)context) {
+    size_t fpregs_offset = pointer_delta(((const ucontext_t*)context)->uc_mcontext.fpregs, context, 1);
+    if (fpregs_offset < sizeof(ucontext_t)) {
+      // Preserve the offset.
+      *((void**) &g_stored_assertion_context.uc_mcontext.fpregs) = (void*)((address)(void*)&g_stored_assertion_context + fpregs_offset);
+    }
+  }
+#endif
 #endif
 }