--- openjdk.orig/hotspot/src/cpu/ppc/vm/macroAssembler_ppc.cpp
+++ openjdk/hotspot/src/cpu/ppc/vm/macroAssembler_ppc.cpp
@@ -1211,7 +1211,11 @@
   // the safepoing polling page.
   ucontext_t* uc = (ucontext_t*) ucontext;
   // Set polling address.
+#if defined(__GLIBC__) || defined(__UCLIBC__)
   address addr = (address)uc->uc_mcontext.regs->gpr[ra] + (ssize_t)ds;
+#else // Musl
+  address addr = (address)uc->uc_mcontext.gp_regs[ra] + (ssize_t)ds;
+#endif
   if (polling_address_ptr != NULL) {
     *polling_address_ptr = addr;
   }
@@ -1232,15 +1236,24 @@
     int rb = inv_rb_field(instruction);
 
     // look up content of ra and rb in ucontext
+#if defined(__GLIBC__) || defined(__UCLIBC__)
     address ra_val=(address)uc->uc_mcontext.regs->gpr[ra];
     long rb_val=(long)uc->uc_mcontext.regs->gpr[rb];
+#else // Musl
+    address ra_val=(address)uc->uc_mcontext.gp_regs[ra];
+    long rb_val=(long)uc->uc_mcontext.gp_regs[rb];
+#endif
     return os::is_memory_serialize_page(thread, ra_val+rb_val);
   } else if (is_stw(instruction) || is_stwu(instruction)) {
     int ra = inv_ra_field(instruction);
     int d1 = inv_d1_field(instruction);
 
     // look up content of ra in ucontext
+#if defined(__GLIBC__) || defined(__UCLIBC__)
     address ra_val=(address)uc->uc_mcontext.regs->gpr[ra];
+#else // Musl
+    address ra_val=(address)uc->uc_mcontext.gp_regs[ra];
+#endif
     return os::is_memory_serialize_page(thread, ra_val+d1);
   } else {
     return false;
@@ -1303,11 +1316,20 @@
       || (is_stdu(instruction) && rs == 1)) {
     int ds = inv_ds_field(instruction);
     // return banged address
+#if defined(__GLIBC__) || defined(__UCLIBC__)
     return ds+(address)uc->uc_mcontext.regs->gpr[ra];
+#else // Musl
+    return ds+(address)uc->uc_mcontext.gp_regs[ra];
+#endif
   } else if (is_stdux(instruction) && rs == 1) {
     int rb = inv_rb_field(instruction);
+#if defined(__GLIBC__) || defined(__UCLIBC__)
     address sp = (address)uc->uc_mcontext.regs->gpr[1];
     long rb_val = (long)uc->uc_mcontext.regs->gpr[rb];
+#else // Musl
+    address sp = (address)uc->uc_mcontext.gp_regs[1];
+    long rb_val = (long)uc->uc_mcontext.gp_regs[rb];
+#endif
     return ra != 1 || rb_val >= 0 ? NULL         // not a stack bang
                                   : sp + rb_val; // banged address
   }
--- openjdk.orig/hotspot/src/os_cpu/linux_ppc/vm/os_linux_ppc.cpp
+++ openjdk/hotspot/src/os_cpu/linux_ppc/vm/os_linux_ppc.cpp
@@ -123,11 +123,19 @@
   //   it because the volatile registers are not needed to make setcontext() work.
   //   Hopefully it was zero'd out beforehand.
   guarantee(uc->uc_mcontext.regs != NULL, "only use ucontext_get_pc in sigaction context");
+#if defined(__GLIBC__) || defined(__UCLIBC__)
   return (address)uc->uc_mcontext.regs->nip;
+#else // Musl
+  return (address)uc->uc_mcontext.gp_regs[32];
+#endif
 }
 
 intptr_t* os::Linux::ucontext_get_sp(ucontext_t * uc) {
+#if defined(__GLIBC__) || defined(__UCLIBC__)
   return (intptr_t*)uc->uc_mcontext.regs->gpr[1/*REG_SP*/];
+#else // Musl
+  return (intptr_t*)uc->uc_mcontext.gp_regs[1/*REG_SP*/];
+#endif
 }
 
 intptr_t* os::Linux::ucontext_get_fp(ucontext_t * uc) {
@@ -226,7 +234,11 @@
   if (uc) {
     address const pc = os::Linux::ucontext_get_pc(uc);
     if (pc && StubRoutines::is_safefetch_fault(pc)) {
+#if defined(__GLIBC__) || defined(__UCLIBC__)
       uc->uc_mcontext.regs->nip = (unsigned long)StubRoutines::continuation_for_safefetch_fault(pc);
+#else // Musl
+      uc->uc_mcontext.gp_regs[32] = (unsigned long)StubRoutines::continuation_for_safefetch_fault(pc);
+#endif
       return true;
     }
   }
@@ -370,7 +382,11 @@
           // continue at the next instruction after the faulting read. Returning
           // garbage from this read is ok.
           thread->set_pending_unsafe_access_error();
+#if defined(__GLIBC__) || defined(__UCLIBC__)
           uc->uc_mcontext.regs->nip = ((unsigned long)pc) + 4;
+#else // Musl
+          uc->uc_mcontext.gp_regs[32] = ((unsigned long)pc) + 4;
+#endif
           return true;
         }
       }
@@ -389,7 +405,11 @@
         // continue at the next instruction after the faulting read. Returning
         // garbage from this read is ok.
         thread->set_pending_unsafe_access_error();
+#if defined(__GLIBC__) || defined(__UCLIBC__)
         uc->uc_mcontext.regs->nip = ((unsigned long)pc) + 4;
+#else // Musl
+        uc->uc_mcontext.gp_regs[32] = ((unsigned long)pc) + 4;
+#endif
         return true;
       }
     }
@@ -412,7 +432,11 @@
   if (stub != NULL) {
     // Save all thread context in case we need to restore it.
     if (thread != NULL) thread->set_saved_exception_pc(pc);
+#if defined(__GLIBC__) || defined(__UCLIBC__)
     uc->uc_mcontext.regs->nip = (unsigned long)stub;
+#else // Musl
+    uc->uc_mcontext.gp_regs[32] = (unsigned long)stub;
+#endif
     return true;
   }
 
@@ -570,6 +594,7 @@
   ucontext_t* uc = (ucontext_t*)context;
 
   st->print_cr("Registers:");
+#if defined(__GLIBC__) || defined(__UCLIBC__)
   st->print("pc =" INTPTR_FORMAT "  ", uc->uc_mcontext.regs->nip);
   st->print("lr =" INTPTR_FORMAT "  ", uc->uc_mcontext.regs->link);
   st->print("ctr=" INTPTR_FORMAT "  ", uc->uc_mcontext.regs->ctr);
@@ -578,8 +603,18 @@
     st->print("r%-2d=" INTPTR_FORMAT "  ", i, uc->uc_mcontext.regs->gpr[i]);
     if (i % 3 == 2) st->cr();
   }
+#else // Musl
+  st->print("pc =" INTPTR_FORMAT "  ", uc->uc_mcontext.gp_regs[32]);
+  st->print("lr =" INTPTR_FORMAT "  ", uc->uc_mcontext.gp_regs[36]);
+  st->print("ctr=" INTPTR_FORMAT "  ", uc->uc_mcontext.gp_regs[35]);
   st->cr();
+  for (int i = 0; i < 32; i++) {
+    st->print("r%-2d=" INTPTR_FORMAT "  ", i, uc->uc_mcontext.gp_regs[i]);
+    if (i % 3 == 2) st->cr();
+  }
+#endif
   st->cr();
+  st->cr();
 
   intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
   st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
@@ -606,7 +641,11 @@
   // this is only for the "general purpose" registers
   for (int i = 0; i < 32; i++) {
     st->print("r%-2d=", i);
+#if defined(__GLIBC__) || defined(__UCLIBC__)
     print_location(st, uc->uc_mcontext.regs->gpr[i]);
+#else // Musl
+    print_location(st, uc->uc_mcontext.gp_regs[i]);
+#endif
   }
   st->cr();
 }