fix copyright fubar, reduce diffs
15254 %ymm registers not restored after signal handler
15367 x86 getfpregs() summons corrupting %xmm ghosts
15333 want x86 /proc xregs support (libc_db, libproc, mdb, etc.)
15336 want libc functions for extended ucontext_t
15334 want ps_lwphandle-specific reg routines
15328 FPU_CW_INIT mistreats reserved bit
15335 i86pc fpu_subr.c isn't really platform-specific
15332 setcontext(2) isn't actually noreturn
15331 need <sys/stdalign.h>
Change-Id: I7060aa86042dfb989f77fc3323c065ea2eafa9ad
Conflicts:
    usr/src/uts/common/fs/proc/prcontrol.c
    usr/src/uts/intel/os/archdep.c
    usr/src/uts/intel/sys/ucontext.h
    usr/src/uts/intel/syscall/getcontext.c

@@ -18,15 +18,14 @@
  *
  * CDDL HEADER END
  */
 /*
  * Copyright (c) 1994, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2017, Joyent, Inc.
  * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
  * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
  * Copyright 2018, Joyent, Inc.
- * Copyright 2020 Oxide Computer Company
+ * Copyright 2023 Oxide Computer Company
  */
 
 /*
  * Kernel memory allocator, as described in the following two papers and a
  * statement about the consolidator:

@@ -2818,10 +2817,36 @@
         ASSERT(head == NULL);
         ASSERT(nbufs == 0);
         mutex_enter(&cp->cache_lock);
 }
 
+/*
+ * kmem_rezalloc() is currently considered private until we sort out how we want
+ * to handle realloc vs. reallocf style interfaces.
+ */
+void *
+kmem_rezalloc(void *oldbuf, size_t oldsize, size_t newsize, int kmflag)
+{
+        void *newbuf = kmem_alloc(newsize, kmflag);
+        if (newbuf == NULL) {
+                return (NULL);
+        }
+
+        bcopy(oldbuf, newbuf, MIN(oldsize, newsize));
+        if (newsize > oldsize) {
+                void *start = (void *)((uintptr_t)newbuf + oldsize);
+                bzero(start, newsize - oldsize);
+        }
+
+        if (oldbuf != NULL) {
+                ASSERT3U(oldsize, !=, 0);
+                kmem_free(oldbuf, oldsize);
+        }
+
+        return (newbuf);
+}
+
 void *
 kmem_zalloc(size_t size, int kmflag)
 {
         size_t index;
         void *buf;