diff options
Diffstat (limited to 'arch/v850/kernel/module.c')
-rw-r--r-- | arch/v850/kernel/module.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/arch/v850/kernel/module.c b/arch/v850/kernel/module.c new file mode 100644 index 000000000000..64aeb3e37c52 --- /dev/null +++ b/arch/v850/kernel/module.c @@ -0,0 +1,237 @@ +/* + * arch/v850/kernel/module.c -- Architecture-specific module functions + * + * Copyright (C) 2002,03 NEC Electronics Corporation + * Copyright (C) 2002,03 Miles Bader <miles@gnu.org> + * Copyright (C) 2001,03 Rusty Russell + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file COPYING in the main directory of this + * archive for more details. + * + * Written by Miles Bader <miles@gnu.org> + * + * Derived in part from arch/ppc/kernel/module.c + */ + +#include <linux/kernel.h> +#include <linux/vmalloc.h> +#include <linux/moduleloader.h> +#include <linux/elf.h> + +#if 0 +#define DEBUGP printk +#else +#define DEBUGP(fmt , ...) +#endif + +void *module_alloc (unsigned long size) +{ + return size == 0 ? 0 : vmalloc (size); +} + +void module_free (struct module *mod, void *module_region) +{ + vfree (module_region); + /* FIXME: If module_region == mod->init_region, trim exception + table entries. */ +} + +int module_finalize (const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, + struct module *mod) +{ + return 0; +} + +/* Count how many different relocations (different symbol, different + addend) */ +static unsigned int count_relocs(const Elf32_Rela *rela, unsigned int num) +{ + unsigned int i, j, ret = 0; + + /* Sure, this is order(n^2), but it's usually short, and not + time critical */ + for (i = 0; i < num; i++) { + for (j = 0; j < i; j++) { + /* If this addend appeared before, it's + already been counted */ + if (ELF32_R_SYM(rela[i].r_info) + == ELF32_R_SYM(rela[j].r_info) + && rela[i].r_addend == rela[j].r_addend) + break; + } + if (j == i) ret++; + } + return ret; +} + +/* Get the potential trampolines size required of the init and + non-init sections */ +static unsigned long get_plt_size(const Elf32_Ehdr *hdr, + const Elf32_Shdr *sechdrs, + const char *secstrings, + int is_init) +{ + unsigned long ret = 0; + unsigned i; + + /* Everything marked ALLOC (this includes the exported + symbols) */ + for (i = 1; i < hdr->e_shnum; i++) { + /* If it's called *.init*, and we're not init, we're + not interested */ + if ((strstr(secstrings + sechdrs[i].sh_name, ".init") != 0) + != is_init) + continue; + + if (sechdrs[i].sh_type == SHT_RELA) { + DEBUGP("Found relocations in section %u\n", i); + DEBUGP("Ptr: %p. Number: %u\n", + (void *)hdr + sechdrs[i].sh_offset, + sechdrs[i].sh_size / sizeof(Elf32_Rela)); + ret += count_relocs((void *)hdr + + sechdrs[i].sh_offset, + sechdrs[i].sh_size + / sizeof(Elf32_Rela)) + * sizeof(struct v850_plt_entry); + } + } + + return ret; +} + +int module_frob_arch_sections(Elf32_Ehdr *hdr, + Elf32_Shdr *sechdrs, + char *secstrings, + struct module *me) +{ + unsigned int i; + + /* Find .plt and .pltinit sections */ + for (i = 0; i < hdr->e_shnum; i++) { + if (strcmp(secstrings + sechdrs[i].sh_name, ".init.plt") == 0) + me->arch.init_plt_section = i; + else if (strcmp(secstrings + sechdrs[i].sh_name, ".plt") == 0) + me->arch.core_plt_section = i; + } + if (!me->arch.core_plt_section || !me->arch.init_plt_section) { + printk("Module doesn't contain .plt or .plt.init sections.\n"); + return -ENOEXEC; + } + + /* Override their sizes */ + sechdrs[me->arch.core_plt_section].sh_size + = get_plt_size(hdr, sechdrs, secstrings, 0); + sechdrs[me->arch.init_plt_section].sh_size + = get_plt_size(hdr, sechdrs, secstrings, 1); + return 0; +} + +int apply_relocate (Elf32_Shdr *sechdrs, const char *strtab, + unsigned int symindex, unsigned int relsec, + struct module *mod) +{ + printk ("Barf\n"); + return -ENOEXEC; +} + +/* Set up a trampoline in the PLT to bounce us to the distant function */ +static uint32_t do_plt_call (void *location, Elf32_Addr val, + Elf32_Shdr *sechdrs, struct module *mod) +{ + struct v850_plt_entry *entry; + /* Instructions used to do the indirect jump. */ + uint32_t tramp[2]; + + /* We have to trash a register, so we assume that any control + transfer more than 21-bits away must be a function call + (so we can use a call-clobbered register). */ + tramp[0] = 0x0621 + ((val & 0xffff) << 16); /* mov sym, r1 ... */ + tramp[1] = ((val >> 16) & 0xffff) + 0x610000; /* ...; jmp r1 */ + + /* Init, or core PLT? */ + if (location >= mod->module_core + && location < mod->module_core + mod->core_size) + entry = (void *)sechdrs[mod->arch.core_plt_section].sh_addr; + else + entry = (void *)sechdrs[mod->arch.init_plt_section].sh_addr; + + /* Find this entry, or if that fails, the next avail. entry */ + while (entry->tramp[0]) + if (entry->tramp[0] == tramp[0] && entry->tramp[1] == tramp[1]) + return (uint32_t)entry; + else + entry++; + + entry->tramp[0] = tramp[0]; + entry->tramp[1] = tramp[1]; + + return (uint32_t)entry; +} + +int apply_relocate_add (Elf32_Shdr *sechdrs, const char *strtab, + unsigned int symindex, unsigned int relsec, + struct module *mod) +{ + unsigned int i; + Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr; + + DEBUGP ("Applying relocate section %u to %u\n", relsec, + sechdrs[relsec].sh_info); + + for (i = 0; i < sechdrs[relsec].sh_size / sizeof (*rela); i++) { + /* This is where to make the change */ + uint32_t *loc + = ((void *)sechdrs[sechdrs[relsec].sh_info].sh_addr + + rela[i].r_offset); + /* This is the symbol it is referring to. Note that all + undefined symbols have been resolved. */ + Elf32_Sym *sym + = ((Elf32_Sym *)sechdrs[symindex].sh_addr + + ELF32_R_SYM (rela[i].r_info)); + uint32_t val = sym->st_value + rela[i].r_addend; + + switch (ELF32_R_TYPE (rela[i].r_info)) { + case R_V850_32: + /* We write two shorts instead of a long because even + 32-bit insns only need half-word alignment, but + 32-bit data writes need to be long-word aligned. */ + val += ((uint16_t *)loc)[0]; + val += ((uint16_t *)loc)[1] << 16; + ((uint16_t *)loc)[0] = val & 0xffff; + ((uint16_t *)loc)[1] = (val >> 16) & 0xffff; + break; + + case R_V850_22_PCREL: + /* Maybe jump indirectly via a PLT table entry. */ + if ((int32_t)(val - (uint32_t)loc) > 0x1fffff + || (int32_t)(val - (uint32_t)loc) < -0x200000) + val = do_plt_call (loc, val, sechdrs, mod); + + val -= (uint32_t)loc; + + /* We write two shorts instead of a long because + even 32-bit insns only need half-word alignment, + but 32-bit data writes need to be long-word + aligned. */ + ((uint16_t *)loc)[0] = + (*(uint16_t *)loc & 0xffc0) /* opcode + reg */ + | ((val >> 16) & 0xffc03f); /* offs high */ + ((uint16_t *)loc)[1] = + (val & 0xffff); /* offs low */ + break; + + default: + printk (KERN_ERR "module %s: Unknown reloc: %u\n", + mod->name, ELF32_R_TYPE (rela[i].r_info)); + return -ENOEXEC; + } + } + + return 0; +} + +void +module_arch_cleanup(struct module *mod) +{ +} |