Subject: Fix compilation with different ucontext_t on musl
Upstream: No
Author: Simon Frankenberger <simon-alpine@fraho.eu>

The machine state registers have to be accessed differently when
running on musl libc. This patch fix this by replacing
"uc_mcontext.regs->grp" with "uc_mcontext.gp_regs"
and accessing the named fields (like "->nip") by the array index constants.

--- old/src/hotspot/cpu/ppc/macroAssembler_ppc.cpp
+++ new/src/hotspot/cpu/ppc/macroAssembler_ppc.cpp
@@ -1290,7 +1290,11 @@
   // 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;
   }
@@ -1311,15 +1315,24 @@
     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;
@@ -1382,11 +1395,20 @@
       || (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
   }
--- old/src/hotspot/cpu/ppc/vm_version_ppc.cpp
+++ new/src/hotspot/cpu/ppc/vm_version_ppc.cpp
@@ -921,7 +921,7 @@
   unsigned long auxv = getauxval(AT_HWCAP2);
 
   if (auxv & PPC_FEATURE2_HTM_NOSC) {
-    if (auxv & PPC_FEATURE2_HAS_HTM) {
+    if (auxv & PPC_FEATURE2_HTM) {
       // TM on POWER8 and POWER9 in compat mode (VM) is supported by the JVM.
       // TM on POWER9 DD2.1 NV (baremetal) is not supported by the JVM (TM on
       // POWER9 DD2.1 NV has a few issues that need a couple of firmware
--- old/src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp
+++ new/src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp
@@ -76,6 +76,9 @@
 # include <poll.h>
 # include <ucontext.h>

+#if ! (defined(__GLIBC__) || defined(__UCLIBC__))
+# include <asm/ptrace.h>
+#endif

 address os::current_stack_pointer() {
   intptr_t* csp;
@@ -108,24 +108,42 @@
   // - if uc was filled by getcontext(), it is undefined - getcontext() does not fill
   //   it because the volatile registers are not needed to make setcontext() work.
   //   Hopefully it was zero'd out beforehand.
+#if defined(__GLIBC__) || defined(__UCLIBC__)
   guarantee(uc->uc_mcontext.regs != NULL, "only use ucontext_get_pc in sigaction context");
   return (address)uc->uc_mcontext.regs->nip;
+#else // Musl
+  guarantee(uc->uc_mcontext.gp_regs != NULL, "only use ucontext_get_pc in sigaction context");
+  return (address)uc->uc_mcontext.gp_regs[PT_NIP];
+#endif
 }
 
 // modify PC in ucontext.
 // Note: Only use this for an ucontext handed down to a signal handler. See comment
 // in ucontext_get_pc.
 void os::Linux::ucontext_set_pc(ucontext_t * uc, address pc) {
+#if defined(__GLIBC__) || defined(__UCLIBC__)
   guarantee(uc->uc_mcontext.regs != NULL, "only use ucontext_set_pc in sigaction context");
   uc->uc_mcontext.regs->nip = (unsigned long)pc;
+#else // Musl
+  guarantee(uc->uc_mcontext.gp_regs != NULL, "only use ucontext_set_pc in sigaction context");
+  uc->uc_mcontext.gp_regs[PT_NIP] = (unsigned long)pc;
+#endif
 }
 
 static address ucontext_get_lr(const ucontext_t * uc) {
+#if defined(__GLIBC__) || defined(__UCLIBC__)
   return (address)uc->uc_mcontext.regs->link;
+#else // Musl
+  return (address)uc->uc_mcontext.gp_regs[PT_LNK];
+#endif
 }
 
 intptr_t* os::Linux::ucontext_get_sp(const 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(const ucontext_t * uc) {
@@ -133,7 +151,11 @@
 }
 
 static unsigned long ucontext_get_trap(const ucontext_t * uc) {
+#if defined(__GLIBC__) || defined(__UCLIBC__)
   return uc->uc_mcontext.regs->trap;
+#else // Musl
+  return uc->uc_mcontext.gp_regs[PT_TRAP];
+#endif
 }
 
 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
@@ -259,7 +279,11 @@
     // 3.2.1 "Machine State Register"), however note that ISA notation for bit
     // numbering is MSB 0, so for normal bit numbering (LSB 0) they come to be
     // bits 33 and 34. It's not related to endianness, just a notation matter.
+#if defined(__GLIBC__) || defined(__UCLIBC__)
     if (second_uc->uc_mcontext.regs->msr & 0x600000000) {
+#else // Musl
+    if (second_uc->uc_mcontext.gp_regs[PT_MSR] & 0x600000000) {
+#endif
       if (TraceTraps) {
         tty->print_cr("caught signal in transaction, "
                         "ignoring to jump to abort handler");
@@ -587,6 +615,7 @@
   const ucontext_t* uc = (const 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);
@@ -595,8 +624,18 @@
     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[PT_NIP]);
+  st->print("lr =" INTPTR_FORMAT "  ", uc->uc_mcontext.gp_regs[PT_LNK]);
+  st->print("ctr=" INTPTR_FORMAT "  ", uc->uc_mcontext.gp_regs[PT_CTR]);
   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 ")", p2i(sp));
@@ -619,12 +658,22 @@
   st->print_cr("Register to memory mapping:");
   st->cr();
 
+#if defined(__GLIBC__) || defined(__UCLIBC__)
   st->print("pc ="); print_location(st, (intptr_t)uc->uc_mcontext.regs->nip);
   st->print("lr ="); print_location(st, (intptr_t)uc->uc_mcontext.regs->link);
   st->print("ctr ="); print_location(st, (intptr_t)uc->uc_mcontext.regs->ctr);
+#else // Musl
+  st->print("pc ="); print_location(st, (intptr_t)uc->uc_mcontext.gp_regs[PT_NIP]);
+  st->print("lr ="); print_location(st, (intptr_t)uc->uc_mcontext.gp_regs[PT_LNK]);
+  st->print("ctr ="); print_location(st, (intptr_t)uc->uc_mcontext.gp_regs[PT_CTR]);
+#endif
   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();
 }
--- old/src/hotspot/os_cpu/linux_ppc/thread_linux_ppc.cpp
+++ new/src/hotspot/os_cpu/linux_ppc/thread_linux_ppc.cpp
@@ -27,6 +27,10 @@
 #include "runtime/frame.inline.hpp"
 #include "runtime/thread.hpp"
 
+#if ! (defined(__GLIBC__) || defined(__UCLIBC__))
+#include <asm/ptrace.h>
+#endif
+
 frame JavaThread::pd_last_frame() {
   assert(has_last_Java_frame(), "must have last_Java_sp() when suspended");
 
@@ -56,8 +56,13 @@
   // if we were running Java code when SIGPROF came in.
   if (isInJava) {
     ucontext_t* uc = (ucontext_t*) ucontext;
+#if defined(__GLIBC__) || defined(__UCLIBC__)
     frame ret_frame((intptr_t*)uc->uc_mcontext.regs->gpr[1/*REG_SP*/],
                      (address)uc->uc_mcontext.regs->nip);
+#else // Musl
+    frame ret_frame((intptr_t*)uc->uc_mcontext.gp_regs[1/*REG_SP*/],
+                     (address)uc->uc_mcontext.gp_regs[PT_NIP]);
+#endif
 
     if (ret_frame.pc() == NULL) {
       // ucontext wasn't useful
@@ -70,7 +75,11 @@
       if (m == NULL || !m->is_valid_method()) return false;
       if (!Metaspace::contains((const void*)m->constMethod())) return false;
 
+#if defined(__GLIBC__) || defined(__UCLIBC__)
       uint64_t reg_bcp = uc->uc_mcontext.regs->gpr[14/*R14_bcp*/];
+#else // Musl
+      uint64_t reg_bcp = uc->uc_mcontext.gp_regs[14/*R14_bcp*/];
+#endif
       uint64_t istate_bcp = istate->bcp;
       uint64_t code_start = (uint64_t)(m->code_base());
       uint64_t code_end = (uint64_t)(m->code_base() + m->code_size());