238 lines
6.6 KiB
C
238 lines
6.6 KiB
C
/*
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* arch/v850/kernel/module.c -- Architecture-specific module functions
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*
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* Copyright (C) 2002,03 NEC Electronics Corporation
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* Copyright (C) 2002,03 Miles Bader <miles@gnu.org>
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* Copyright (C) 2001,03 Rusty Russell
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*
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* This file is subject to the terms and conditions of the GNU General
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* Public License. See the file COPYING in the main directory of this
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* archive for more details.
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*
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* Written by Miles Bader <miles@gnu.org>
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*
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* Derived in part from arch/ppc/kernel/module.c
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*/
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#include <linux/kernel.h>
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#include <linux/vmalloc.h>
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#include <linux/moduleloader.h>
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#include <linux/elf.h>
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#if 0
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#define DEBUGP printk
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#else
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#define DEBUGP(fmt , ...)
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#endif
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void *module_alloc (unsigned long size)
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{
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return size == 0 ? 0 : vmalloc (size);
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}
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void module_free (struct module *mod, void *module_region)
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{
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vfree (module_region);
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/* FIXME: If module_region == mod->init_region, trim exception
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table entries. */
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}
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int module_finalize (const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
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struct module *mod)
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{
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return 0;
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}
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/* Count how many different relocations (different symbol, different
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addend) */
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static unsigned int count_relocs(const Elf32_Rela *rela, unsigned int num)
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{
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unsigned int i, j, ret = 0;
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/* Sure, this is order(n^2), but it's usually short, and not
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time critical */
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for (i = 0; i < num; i++) {
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for (j = 0; j < i; j++) {
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/* If this addend appeared before, it's
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already been counted */
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if (ELF32_R_SYM(rela[i].r_info)
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== ELF32_R_SYM(rela[j].r_info)
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&& rela[i].r_addend == rela[j].r_addend)
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break;
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}
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if (j == i) ret++;
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}
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return ret;
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}
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/* Get the potential trampolines size required of the init and
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non-init sections */
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static unsigned long get_plt_size(const Elf32_Ehdr *hdr,
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const Elf32_Shdr *sechdrs,
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const char *secstrings,
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int is_init)
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{
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unsigned long ret = 0;
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unsigned i;
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/* Everything marked ALLOC (this includes the exported
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symbols) */
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for (i = 1; i < hdr->e_shnum; i++) {
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/* If it's called *.init*, and we're not init, we're
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not interested */
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if ((strstr(secstrings + sechdrs[i].sh_name, ".init") != 0)
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!= is_init)
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continue;
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if (sechdrs[i].sh_type == SHT_RELA) {
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DEBUGP("Found relocations in section %u\n", i);
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DEBUGP("Ptr: %p. Number: %u\n",
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(void *)hdr + sechdrs[i].sh_offset,
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sechdrs[i].sh_size / sizeof(Elf32_Rela));
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ret += count_relocs((void *)hdr
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+ sechdrs[i].sh_offset,
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sechdrs[i].sh_size
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/ sizeof(Elf32_Rela))
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* sizeof(struct v850_plt_entry);
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}
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}
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return ret;
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}
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int module_frob_arch_sections(Elf32_Ehdr *hdr,
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Elf32_Shdr *sechdrs,
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char *secstrings,
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struct module *me)
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{
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unsigned int i;
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/* Find .plt and .pltinit sections */
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for (i = 0; i < hdr->e_shnum; i++) {
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if (strcmp(secstrings + sechdrs[i].sh_name, ".init.plt") == 0)
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me->arch.init_plt_section = i;
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else if (strcmp(secstrings + sechdrs[i].sh_name, ".plt") == 0)
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me->arch.core_plt_section = i;
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}
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if (!me->arch.core_plt_section || !me->arch.init_plt_section) {
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printk("Module doesn't contain .plt or .plt.init sections.\n");
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return -ENOEXEC;
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}
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/* Override their sizes */
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sechdrs[me->arch.core_plt_section].sh_size
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= get_plt_size(hdr, sechdrs, secstrings, 0);
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sechdrs[me->arch.init_plt_section].sh_size
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= get_plt_size(hdr, sechdrs, secstrings, 1);
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return 0;
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}
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int apply_relocate (Elf32_Shdr *sechdrs, const char *strtab,
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unsigned int symindex, unsigned int relsec,
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struct module *mod)
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{
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printk ("Barf\n");
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return -ENOEXEC;
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}
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/* Set up a trampoline in the PLT to bounce us to the distant function */
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static uint32_t do_plt_call (void *location, Elf32_Addr val,
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Elf32_Shdr *sechdrs, struct module *mod)
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{
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struct v850_plt_entry *entry;
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/* Instructions used to do the indirect jump. */
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uint32_t tramp[2];
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/* We have to trash a register, so we assume that any control
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transfer more than 21-bits away must be a function call
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(so we can use a call-clobbered register). */
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tramp[0] = 0x0621 + ((val & 0xffff) << 16); /* mov sym, r1 ... */
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tramp[1] = ((val >> 16) & 0xffff) + 0x610000; /* ...; jmp r1 */
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/* Init, or core PLT? */
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if (location >= mod->module_core
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&& location < mod->module_core + mod->core_size)
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entry = (void *)sechdrs[mod->arch.core_plt_section].sh_addr;
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else
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entry = (void *)sechdrs[mod->arch.init_plt_section].sh_addr;
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/* Find this entry, or if that fails, the next avail. entry */
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while (entry->tramp[0])
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if (entry->tramp[0] == tramp[0] && entry->tramp[1] == tramp[1])
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return (uint32_t)entry;
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else
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entry++;
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entry->tramp[0] = tramp[0];
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entry->tramp[1] = tramp[1];
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return (uint32_t)entry;
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}
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int apply_relocate_add (Elf32_Shdr *sechdrs, const char *strtab,
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unsigned int symindex, unsigned int relsec,
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struct module *mod)
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{
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unsigned int i;
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Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
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DEBUGP ("Applying relocate section %u to %u\n", relsec,
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sechdrs[relsec].sh_info);
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for (i = 0; i < sechdrs[relsec].sh_size / sizeof (*rela); i++) {
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/* This is where to make the change */
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uint32_t *loc
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= ((void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
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+ rela[i].r_offset);
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/* This is the symbol it is referring to. Note that all
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undefined symbols have been resolved. */
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Elf32_Sym *sym
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= ((Elf32_Sym *)sechdrs[symindex].sh_addr
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+ ELF32_R_SYM (rela[i].r_info));
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uint32_t val = sym->st_value + rela[i].r_addend;
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switch (ELF32_R_TYPE (rela[i].r_info)) {
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case R_V850_32:
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/* We write two shorts instead of a long because even
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32-bit insns only need half-word alignment, but
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32-bit data writes need to be long-word aligned. */
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val += ((uint16_t *)loc)[0];
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val += ((uint16_t *)loc)[1] << 16;
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((uint16_t *)loc)[0] = val & 0xffff;
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((uint16_t *)loc)[1] = (val >> 16) & 0xffff;
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break;
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case R_V850_22_PCREL:
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/* Maybe jump indirectly via a PLT table entry. */
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if ((int32_t)(val - (uint32_t)loc) > 0x1fffff
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|| (int32_t)(val - (uint32_t)loc) < -0x200000)
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val = do_plt_call (loc, val, sechdrs, mod);
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val -= (uint32_t)loc;
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/* We write two shorts instead of a long because
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even 32-bit insns only need half-word alignment,
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but 32-bit data writes need to be long-word
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aligned. */
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((uint16_t *)loc)[0] =
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(*(uint16_t *)loc & 0xffc0) /* opcode + reg */
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| ((val >> 16) & 0xffc03f); /* offs high */
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((uint16_t *)loc)[1] =
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(val & 0xffff); /* offs low */
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break;
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default:
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printk (KERN_ERR "module %s: Unknown reloc: %u\n",
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mod->name, ELF32_R_TYPE (rela[i].r_info));
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return -ENOEXEC;
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}
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}
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return 0;
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}
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void
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module_arch_cleanup(struct module *mod)
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{
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}
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