module.c

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/*  Kernel module help for SH.

    SHcompact version by Kaz Kojima and Paul Mundt.

    SHmedia bits:

    Copyright 2004 SuperH (UK) Ltd
    Author: Richard Curnow

    Based on the sh version, and on code from the sh64-specific parts of
    modutils, originally written by Richard Curnow and Ben Gaster.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
#include <linux/moduleloader.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/bug.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <asm/unaligned.h>
#include <asm/dwarf.h>

int apply_relocate_add(Elf32_Shdr *sechdrs,
           const char *strtab,
           unsigned int symindex,
           unsigned int relsec,
           struct module *me)
{
    unsigned int i;
    Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
    Elf32_Sym *sym;
    Elf32_Addr relocation;
    uint32_t *location;
    uint32_t value;

    pr_debug("Applying relocate section %u to %u\n", relsec,
         sechdrs[relsec].sh_info);
    for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
        /* This is where to make the change */
        location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
            + rel[i].r_offset;
        /* This is the symbol it is referring to.  Note that all
           undefined symbols have been resolved.  */
        sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
            + ELF32_R_SYM(rel[i].r_info);
        relocation = sym->st_value + rel[i].r_addend;

#ifdef CONFIG_SUPERH64
        /* For text addresses, bit2 of the st_other field indicates
         * whether the symbol is SHmedia (1) or SHcompact (0).  If
         * SHmedia, the LSB of the symbol needs to be asserted
         * for the CPU to be in SHmedia mode when it starts executing
         * the branch target. */
        relocation |= !!(sym->st_other & 4);
#endif

        switch (ELF32_R_TYPE(rel[i].r_info)) {
        case R_SH_NONE:
            break;
        case R_SH_DIR32:
            value = get_unaligned(location);
            value += relocation;
            put_unaligned(value, location);
            break;
        case R_SH_REL32:
            relocation = (relocation - (Elf32_Addr) location);
            value = get_unaligned(location);
            value += relocation;
            put_unaligned(value, location);
            break;
        case R_SH_IMM_LOW16:
            *location = (*location & ~0x3fffc00) |
                ((relocation & 0xffff) << 10);
            break;
        case R_SH_IMM_MEDLOW16:
            *location = (*location & ~0x3fffc00) |
                (((relocation >> 16) & 0xffff) << 10);
            break;
        case R_SH_IMM_LOW16_PCREL:
            relocation -= (Elf32_Addr) location;
            *location = (*location & ~0x3fffc00) |
                ((relocation & 0xffff) << 10);
            break;
        case R_SH_IMM_MEDLOW16_PCREL:
            relocation -= (Elf32_Addr) location;
            *location = (*location & ~0x3fffc00) |
                (((relocation >> 16) & 0xffff) << 10);
            break;
        default:
            printk(KERN_ERR "module %s: Unknown relocation: %u\n",
                   me->name, ELF32_R_TYPE(rel[i].r_info));
            return -ENOEXEC;
        }
    }
    return 0;
}

int module_finalize(const Elf_Ehdr *hdr,
            const Elf_Shdr *sechdrs,
            struct module *me)
{
    int ret = 0;

    ret |= module_dwarf_finalize(hdr, sechdrs, me);

    return ret;
}

void module_arch_cleanup(struct module *mod)
{
    module_dwarf_cleanup(mod);
}