From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001 From: root Date: Fri, 25 Dec 2015 04:40:36 +0000 Subject: initial_commit --- arch/alpha/kernel/module.c | 316 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 316 insertions(+) create mode 100644 arch/alpha/kernel/module.c (limited to 'arch/alpha/kernel/module.c') diff --git a/arch/alpha/kernel/module.c b/arch/alpha/kernel/module.c new file mode 100644 index 00000000..ebc3c894 --- /dev/null +++ b/arch/alpha/kernel/module.c @@ -0,0 +1,316 @@ +/* Kernel module help for Alpha. + Copyright (C) 2002 Richard Henderson. + + 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 +#include +#include +#include +#include +#include +#include + +#if 0 +#define DEBUGP printk +#else +#define DEBUGP(fmt...) +#endif + +void * +module_alloc(unsigned long size) +{ + if (size == 0) + return NULL; + return vmalloc(size); +} + +void +module_free(struct module *mod, void *module_region) +{ + vfree(module_region); +} + +/* Allocate the GOT at the end of the core sections. */ + +struct got_entry { + struct got_entry *next; + Elf64_Sxword r_addend; + int got_offset; +}; + +static inline void +process_reloc_for_got(Elf64_Rela *rela, + struct got_entry *chains, Elf64_Xword *poffset) +{ + unsigned long r_sym = ELF64_R_SYM (rela->r_info); + unsigned long r_type = ELF64_R_TYPE (rela->r_info); + Elf64_Sxword r_addend = rela->r_addend; + struct got_entry *g; + + if (r_type != R_ALPHA_LITERAL) + return; + + for (g = chains + r_sym; g ; g = g->next) + if (g->r_addend == r_addend) { + if (g->got_offset == 0) { + g->got_offset = *poffset; + *poffset += 8; + } + goto found_entry; + } + + g = kmalloc (sizeof (*g), GFP_KERNEL); + g->next = chains[r_sym].next; + g->r_addend = r_addend; + g->got_offset = *poffset; + *poffset += 8; + chains[r_sym].next = g; + + found_entry: + /* Trick: most of the ELF64_R_TYPE field is unused. There are + 42 valid relocation types, and a 32-bit field. Co-opt the + bits above 256 to store the got offset for this reloc. */ + rela->r_info |= g->got_offset << 8; +} + +int +module_frob_arch_sections(Elf64_Ehdr *hdr, Elf64_Shdr *sechdrs, + char *secstrings, struct module *me) +{ + struct got_entry *chains; + Elf64_Rela *rela; + Elf64_Shdr *esechdrs, *symtab, *s, *got; + unsigned long nsyms, nrela, i; + + esechdrs = sechdrs + hdr->e_shnum; + symtab = got = NULL; + + /* Find out how large the symbol table is. Allocate one got_entry + head per symbol. Normally this will be enough, but not always. + We'll chain different offsets for the symbol down each head. */ + for (s = sechdrs; s < esechdrs; ++s) + if (s->sh_type == SHT_SYMTAB) + symtab = s; + else if (!strcmp(".got", secstrings + s->sh_name)) { + got = s; + me->arch.gotsecindex = s - sechdrs; + } + + if (!symtab) { + printk(KERN_ERR "module %s: no symbol table\n", me->name); + return -ENOEXEC; + } + if (!got) { + printk(KERN_ERR "module %s: no got section\n", me->name); + return -ENOEXEC; + } + + nsyms = symtab->sh_size / sizeof(Elf64_Sym); + chains = kcalloc(nsyms, sizeof(struct got_entry), GFP_KERNEL); + if (!chains) { + printk(KERN_ERR + "module %s: no memory for symbol chain buffer\n", + me->name); + return -ENOMEM; + } + + got->sh_size = 0; + got->sh_addralign = 8; + got->sh_type = SHT_NOBITS; + + /* Examine all LITERAL relocations to find out what GOT entries + are required. This sizes the GOT section as well. */ + for (s = sechdrs; s < esechdrs; ++s) + if (s->sh_type == SHT_RELA) { + nrela = s->sh_size / sizeof(Elf64_Rela); + rela = (void *)hdr + s->sh_offset; + for (i = 0; i < nrela; ++i) + process_reloc_for_got(rela+i, chains, + &got->sh_size); + } + + /* Free the memory we allocated. */ + for (i = 0; i < nsyms; ++i) { + struct got_entry *g, *n; + for (g = chains[i].next; g ; g = n) { + n = g->next; + kfree(g); + } + } + kfree(chains); + + return 0; +} + +int +apply_relocate(Elf64_Shdr *sechdrs, const char *strtab, unsigned int symindex, + unsigned int relsec, struct module *me) +{ + printk(KERN_ERR "module %s: REL relocation unsupported\n", me->name); + return -ENOEXEC; +} + +int +apply_relocate_add(Elf64_Shdr *sechdrs, const char *strtab, + unsigned int symindex, unsigned int relsec, + struct module *me) +{ + Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr; + unsigned long i, n = sechdrs[relsec].sh_size / sizeof(*rela); + Elf64_Sym *symtab, *sym; + void *base, *location; + unsigned long got, gp; + + DEBUGP("Applying relocate section %u to %u\n", relsec, + sechdrs[relsec].sh_info); + + base = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr; + symtab = (Elf64_Sym *)sechdrs[symindex].sh_addr; + + /* The small sections were sorted to the end of the segment. + The following should definitely cover them. */ + gp = (u64)me->module_core + me->core_size - 0x8000; + got = sechdrs[me->arch.gotsecindex].sh_addr; + + for (i = 0; i < n; i++) { + unsigned long r_sym = ELF64_R_SYM (rela[i].r_info); + unsigned long r_type = ELF64_R_TYPE (rela[i].r_info); + unsigned long r_got_offset = r_type >> 8; + unsigned long value, hi, lo; + r_type &= 0xff; + + /* This is where to make the change. */ + location = base + rela[i].r_offset; + + /* This is the symbol it is referring to. Note that all + unresolved symbols have been resolved. */ + sym = symtab + r_sym; + value = sym->st_value + rela[i].r_addend; + + switch (r_type) { + case R_ALPHA_NONE: + break; + case R_ALPHA_REFQUAD: + /* BUG() can produce misaligned relocations. */ + ((u32 *)location)[0] = value; + ((u32 *)location)[1] = value >> 32; + break; + case R_ALPHA_GPREL32: + value -= gp; + if ((int)value != value) + goto reloc_overflow; + *(u32 *)location = value; + break; + case R_ALPHA_LITERAL: + hi = got + r_got_offset; + lo = hi - gp; + if ((short)lo != lo) + goto reloc_overflow; + *(u16 *)location = lo; + *(u64 *)hi = value; + break; + case R_ALPHA_LITUSE: + break; + case R_ALPHA_GPDISP: + value = gp - (u64)location; + lo = (short)value; + hi = (int)(value - lo); + if (hi + lo != value) + goto reloc_overflow; + *(u16 *)location = hi >> 16; + *(u16 *)(location + rela[i].r_addend) = lo; + break; + case R_ALPHA_BRSGP: + /* BRSGP is only allowed to bind to local symbols. + If the section is undef, this means that the + value was resolved from somewhere else. */ + if (sym->st_shndx == SHN_UNDEF) + goto reloc_overflow; + if ((sym->st_other & STO_ALPHA_STD_GPLOAD) == + STO_ALPHA_STD_GPLOAD) + /* Omit the prologue. */ + value += 8; + /* FALLTHRU */ + case R_ALPHA_BRADDR: + value -= (u64)location + 4; + if (value & 3) + goto reloc_overflow; + value = (long)value >> 2; + if (value + (1<<21) >= 1<<22) + goto reloc_overflow; + value &= 0x1fffff; + value |= *(u32 *)location & ~0x1fffff; + *(u32 *)location = value; + break; + case R_ALPHA_HINT: + break; + case R_ALPHA_SREL32: + value -= (u64)location; + if ((int)value != value) + goto reloc_overflow; + *(u32 *)location = value; + break; + case R_ALPHA_SREL64: + value -= (u64)location; + *(u64 *)location = value; + break; + case R_ALPHA_GPRELHIGH: + value = (long)(value - gp + 0x8000) >> 16; + if ((short) value != value) + goto reloc_overflow; + *(u16 *)location = value; + break; + case R_ALPHA_GPRELLOW: + value -= gp; + *(u16 *)location = value; + break; + case R_ALPHA_GPREL16: + value -= gp; + if ((short) value != value) + goto reloc_overflow; + *(u16 *)location = value; + break; + default: + printk(KERN_ERR "module %s: Unknown relocation: %lu\n", + me->name, r_type); + return -ENOEXEC; + reloc_overflow: + if (ELF64_ST_TYPE (sym->st_info) == STT_SECTION) + printk(KERN_ERR + "module %s: Relocation (type %lu) overflow vs section %d\n", + me->name, r_type, sym->st_shndx); + else + printk(KERN_ERR + "module %s: Relocation (type %lu) overflow vs %s\n", + me->name, r_type, strtab + sym->st_name); + return -ENOEXEC; + } + } + + return 0; +} + +int +module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, + struct module *me) +{ + return 0; +} + +void +module_arch_cleanup(struct module *mod) +{ +} -- cgit v1.2.3