*** 413,422 ****
--- 413,429 ----
           */
          if (src->uc_flags & UC_FPU)
                  fpregset_32ton(&src->uc_mcontext.fpregs,
                      &dst->uc_mcontext.fpregs);
  
+         /*
+          * Copy the brand-private data:
+          */
+         dst->uc_brand_data[0] = (void *)(uintptr_t)src->uc_brand_data[0];
+         dst->uc_brand_data[1] = (void *)(uintptr_t)src->uc_brand_data[1];
+         dst->uc_brand_data[2] = (void *)(uintptr_t)src->uc_brand_data[2];
+ 
          if (src->uc_flags & UC_XSAVE) {
                  dst->uc_xsave = (long)(uint32_t)src->uc_xsave;
          } else {
                  dst->uc_xsave = 0;
          }
*** 472,484 ****
  
  #define IS_CS           1
  #define IS_NOT_CS       0
  
  /*ARGSUSED*/
! static greg_t
  fix_segreg(greg_t sr, int iscs, model_t datamodel)
  {
          switch (sr &= 0xffff) {
  
          case 0:
                  if (iscs == IS_CS)
                          return (0 | SEL_UPL);
--- 479,493 ----
  
  #define IS_CS           1
  #define IS_NOT_CS       0
  
  /*ARGSUSED*/
! greg_t
  fix_segreg(greg_t sr, int iscs, model_t datamodel)
  {
+         kthread_t *t = curthread;
+ 
          switch (sr &= 0xffff) {
  
          case 0:
                  if (iscs == IS_CS)
                          return (0 | SEL_UPL);
*** 506,515 ****
--- 515,537 ----
                  return (sr);
          default:
                  break;
          }
  
+         /*
+          * Allow this process's brand to do any necessary segment register
+          * manipulation.
+          */
+         if (PROC_IS_BRANDED(t->t_procp) && BRMOP(t->t_procp)->b_fixsegreg) {
+                 greg_t bsr = BRMOP(t->t_procp)->b_fixsegreg(sr, datamodel);
+ 
+                 if (bsr == 0 && iscs == IS_CS)
+                         return (0 | SEL_UPL);
+                 else
+                         return (bsr);
+         }
+ 
          /*
           * Force it into the LDT in ring 3 for 32-bit processes, which by
           * default do not have an LDT, so that any attempt to use an invalid
           * selector will reference the (non-existant) LDT, and cause a #gp
           * fault for the process.