/*      $NetBSD: kobj_rename.c,v 1.3 2020/02/20 22:52:10 joerg Exp $    */

/*-
* Copyright (c) 2010 Antti Kantee.  All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kobj_rename.c,v 1.3 2020/02/20 22:52:10 joerg Exp $");

#define ELFSIZE ARCH_ELFSIZE

#include <sys/param.h>
#include <sys/exec_elf.h>
#include <sys/kmem.h>
#include <sys/kobj.h>
#include <sys/systm.h>

#include <rump/rump.h>

/*
* Mangle symbols into rump kernel namespace.  This means
* putting "rumpns" in front of select symbols.
* See src/sys/rump/Makefile.rump for more details on the rump kernel
* namespace.
*/
const char *norentab[] = {
       "RUMP",
       "rump",
       "__",
       "_GLOBAL_OFFSET_TABLE",
       ".TOC.",
};
static int
norename(const char *name)
{
       unsigned i;

       for (i = 0; i < __arraycount(norentab); i++) {
               if (strncmp(norentab[i], name, strlen(norentab[i])) == 0)
                       return 1;
       }
       return 0;
}

#define RUMPNS "rumpns_"
int
kobj_renamespace(Elf_Sym *symtab, size_t symcount,
       char **strtab, size_t *strtabsz)
{
       Elf_Sym *sym;
       char *worktab, *newtab;
       size_t worktabsz, worktabidx;
       unsigned i;
       const size_t prefixlen = strlen(RUMPNS);
       static int warned;

       if (!rump_nativeabi_p() && !warned) {
               printf("warning: kernel ABI not supported on this arch\n");
               warned = 1;
       }

       /* allocate space for worst-case stringtab */
       worktabsz = *strtabsz + symcount * prefixlen;
       worktab = kmem_alloc(worktabsz, KM_SLEEP);

       /* now, adjust stringtab into temporary space */
#define WORKTABP (worktab + worktabidx)
       for (i = 0, worktabidx = 0; i < symcount; i++) {
               const char *fromname;

               sym = &symtab[i];
               if (sym->st_name == 0) {
                       continue;
               }

               fromname = *strtab + sym->st_name;
               sym->st_name = worktabidx;

               if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL ||
                   norename(fromname)) {
                       strcpy(WORKTABP, fromname);
                       worktabidx += strlen(fromname) + 1;
               } else {
                       strcpy(WORKTABP, RUMPNS);
                       worktabidx += prefixlen;
                       strcpy(WORKTABP, fromname);
                       worktabidx += strlen(fromname) + 1;
               }
               KASSERT(worktabidx <= worktabsz);
       }
#undef WORKTABP

       /*
        * Finally, free old strtab, allocate new one, and copy contents.
        */
       kmem_free(*strtab, *strtabsz);
       *strtab = NULL; /* marvin the paradroid 999 */
       newtab = kmem_alloc(worktabidx, KM_SLEEP);
       memcpy(newtab, worktab, worktabidx);

       kmem_free(worktab, worktabsz);

       *strtab = newtab;
       *strtabsz = worktabidx;

       return 0;
}