cregit-Linux how code gets into the kernel

Release 4.11 arch/m32r/kernel/module.c

Directory: arch/m32r/kernel
/*  Kernel module help for M32R.

    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/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>

#if 0
#define DEBUGP printk
#else

#define DEBUGP(fmt...)
#endif


#define COPY_UNALIGNED_WORD(sw, tw, align) \
{ \
        void *__s = &(sw), *__t = &(tw); \
        unsigned short *__s2 = __s, *__t2 =__t; \
        unsigned char *__s1 = __s, *__t1 =__t; \
        switch ((align)) \
        { \
        case 0: \
                *(unsigned long *) __t = *(unsigned long *) __s; \
                break; \
        case 2: \
                *__t2++ = *__s2++; \
                *__t2 = *__s2; \
                break; \
        default: \
                *__t1++ = *__s1++; \
                *__t1++ = *__s1++; \
                *__t1++ = *__s1++; \
                *__t1 = *__s1; \
                break; \
        } \
}


#define COPY_UNALIGNED_HWORD(sw, tw, align) \
  { \
    void *__s = &(sw), *__t = &(tw); \
    unsigned short *__s2 = __s, *__t2 =__t; \
    unsigned char *__s1 = __s, *__t1 =__t; \
    switch ((align)) \
    { \
    case 0: \
      *__t2 = *__s2; \
      break; \
    default: \
      *__t1++ = *__s1++; \
      *__t1 = *__s1; \
      break; \
    } \
  }


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; unsigned short *hlocation; unsigned short hvalue; int svalue; int align; DEBUGP("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; align = (int)location & 3; switch (ELF32_R_TYPE(rel[i].r_info)) { case R_M32R_32_RELA: COPY_UNALIGNED_WORD (*location, value, align); value += relocation; COPY_UNALIGNED_WORD (value, *location, align); break; case R_M32R_HI16_ULO_RELA: COPY_UNALIGNED_WORD (*location, value, align); relocation = (relocation >>16) & 0xffff; /* RELA must has 0 at relocation field. */ value += relocation; COPY_UNALIGNED_WORD (value, *location, align); break; case R_M32R_HI16_SLO_RELA: COPY_UNALIGNED_WORD (*location, value, align); if (relocation & 0x8000) relocation += 0x10000; relocation = (relocation >>16) & 0xffff; /* RELA must has 0 at relocation field. */ value += relocation; COPY_UNALIGNED_WORD (value, *location, align); break; case R_M32R_16_RELA: hlocation = (unsigned short *)location; relocation = relocation & 0xffff; /* RELA must has 0 at relocation field. */ hvalue = relocation; COPY_UNALIGNED_WORD (hvalue, *hlocation, align); break; case R_M32R_SDA16_RELA: case R_M32R_LO16_RELA: COPY_UNALIGNED_WORD (*location, value, align); relocation = relocation & 0xffff; /* RELA must has 0 at relocation field. */ value += relocation; COPY_UNALIGNED_WORD (value, *location, align); break; case R_M32R_24_RELA: COPY_UNALIGNED_WORD (*location, value, align); relocation = relocation & 0xffffff; /* RELA must has 0 at relocation field. */ value += relocation; COPY_UNALIGNED_WORD (value, *location, align); break; case R_M32R_18_PCREL_RELA: relocation = (relocation - (Elf32_Addr) location); if (relocation < -0x20000 || 0x1fffc < relocation) { printk(KERN_ERR "module %s: relocation overflow: %u\n", me->name, relocation); return -ENOEXEC; } COPY_UNALIGNED_WORD (*location, value, align); if (value & 0xffff) { /* RELA must has 0 at relocation field. */ printk(KERN_ERR "module %s: illegal relocation field: %u\n", me->name, value); return -ENOEXEC; } relocation = (relocation >> 2) & 0xffff; value += relocation; COPY_UNALIGNED_WORD (value, *location, align); break; case R_M32R_10_PCREL_RELA: hlocation = (unsigned short *)location; relocation = (relocation - (Elf32_Addr) location); COPY_UNALIGNED_HWORD (*hlocation, hvalue, align); svalue = (int)hvalue; svalue = (signed char)svalue << 2; relocation += svalue; relocation = (relocation >> 2) & 0xff; hvalue = hvalue & 0xff00; hvalue += relocation; COPY_UNALIGNED_HWORD (hvalue, *hlocation, align); break; case R_M32R_26_PCREL_RELA: relocation = (relocation - (Elf32_Addr) location); if (relocation < -0x2000000 || 0x1fffffc < relocation) { printk(KERN_ERR "module %s: relocation overflow: %u\n", me->name, relocation); return -ENOEXEC; } COPY_UNALIGNED_WORD (*location, value, align); if (value & 0xffffff) { /* RELA must has 0 at relocation field. */ printk(KERN_ERR "module %s: illegal relocation field: %u\n", me->name, value); return -ENOEXEC; } relocation = (relocation >> 2) & 0xffffff; value += relocation; COPY_UNALIGNED_WORD (value, *location, align); break; default: printk(KERN_ERR "module %s: Unknown relocation: %u\n", me->name, ELF32_R_TYPE(rel[i].r_info)); return -ENOEXEC; } } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Hirokazu Takata743100.00%1100.00%
Total743100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Hirokazu Takata804100.00%1100.00%
Total804100.00%1100.00%
Directory: arch/m32r/kernel
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