Index: linux-2.6.30.4/arch/mips/Makefile =================================================================== --- linux-2.6.30.4.orig/arch/mips/Makefile 2009-08-06 16:02:25.000000000 +0200 +++ linux-2.6.30.4/arch/mips/Makefile 2009-08-06 16:02:37.000000000 +0200 @@ -83,7 +83,7 @@ cflags-y += -G 0 -mno-abicalls -fno-pic -pipe cflags-y += -msoft-float LDFLAGS_vmlinux += -G 0 -static -n -nostdlib -MODFLAGS += -mlong-calls +MODFLAGS += -mno-long-calls cflags-y += -ffreestanding Index: linux-2.6.30.4/arch/mips/include/asm/module.h =================================================================== --- linux-2.6.30.4.orig/arch/mips/include/asm/module.h 2009-08-06 16:02:25.000000000 +0200 +++ linux-2.6.30.4/arch/mips/include/asm/module.h 2009-08-06 16:02:37.000000000 +0200 @@ -9,6 +9,11 @@ struct list_head dbe_list; const struct exception_table_entry *dbe_start; const struct exception_table_entry *dbe_end; + + void *plt_tbl; + unsigned int core_plt_offset; + unsigned int core_plt_size; + unsigned int init_plt_offset; }; typedef uint8_t Elf64_Byte; /* Type for a 8-bit quantity. */ Index: linux-2.6.30.4/arch/mips/kernel/module.c =================================================================== --- linux-2.6.30.4.orig/arch/mips/kernel/module.c 2009-08-06 16:02:36.000000000 +0200 +++ linux-2.6.30.4/arch/mips/kernel/module.c 2009-08-06 16:03:15.000000000 +0200 @@ -43,6 +43,116 @@ static LIST_HEAD(dbe_list); static DEFINE_SPINLOCK(dbe_lock); +/* + * Get the potential max trampolines size required of the init and + * non-init sections. Only used if we cannot find enough contiguous + * physically mapped memory to put the module into. + */ +static unsigned int +get_plt_size(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, + const char *secstrings, unsigned int symindex, bool is_init) +{ + unsigned long ret = 0; + unsigned int i, j; + Elf_Sym *syms; + + /* Everything marked ALLOC (this includes the exported symbols) */ + for (i = 1; i < hdr->e_shnum; ++i) { + unsigned int info = sechdrs[i].sh_info; + + if (sechdrs[i].sh_type != SHT_REL + && sechdrs[i].sh_type != SHT_RELA) + continue; + + /* Not a valid relocation section? */ + if (info >= hdr->e_shnum) + continue; + + /* Don't bother with non-allocated sections */ + if (!(sechdrs[info].sh_flags & SHF_ALLOC)) + continue; + + /* 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; + + syms = (Elf_Sym *) sechdrs[symindex].sh_addr; + if (sechdrs[i].sh_type == SHT_REL) { + Elf_Mips_Rel *rel = (void *) sechdrs[i].sh_addr; + unsigned int size = sechdrs[i].sh_size / sizeof(*rel); + + for (j = 0; j < size; ++j) { + Elf_Sym *sym; + + if (ELF_MIPS_R_TYPE(rel[j]) != R_MIPS_26) + continue; + + sym = syms + ELF_MIPS_R_SYM(rel[j]); + if (!is_init && sym->st_shndx != SHN_UNDEF) + continue; + + ret += 4 * sizeof(int); + } + } else { + Elf_Mips_Rela *rela = (void *) sechdrs[i].sh_addr; + unsigned int size = sechdrs[i].sh_size / sizeof(*rela); + + for (j = 0; j < size; ++j) { + Elf_Sym *sym; + + if (ELF_MIPS_R_TYPE(rela[j]) != R_MIPS_26) + continue; + + sym = syms + ELF_MIPS_R_SYM(rela[j]); + if (!is_init && sym->st_shndx != SHN_UNDEF) + continue; + + ret += 4 * sizeof(int); + } + } + } + + return ret; +} + +#ifndef MODULE_START +static void *alloc_phys(unsigned long size) +{ + unsigned order; + struct page *page; + struct page *p; + + size = PAGE_ALIGN(size); + order = get_order(size); + + page = alloc_pages(GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN | + __GFP_THISNODE, order); + if (!page) + return NULL; + + split_page(page, order); + + for (p = page + (size >> PAGE_SHIFT); p < page + (1 << order); ++p) + __free_page(p); + + return page_address(page); +} +#endif + +static void free_phys(void *ptr, unsigned long size) +{ + struct page *page; + struct page *end; + + page = virt_to_page(ptr); + end = page + (PAGE_ALIGN(size) >> PAGE_SHIFT); + + for (; page < end; ++page) + __free_page(page); +} + void *module_alloc(unsigned long size) { #ifdef MODULE_START @@ -58,16 +168,45 @@ return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL); #else + void *ptr; + if (size == 0) return NULL; - return vmalloc(size); + + ptr = alloc_phys(size); + + /* If we failed to allocate physically contiguous memory, + * fall back to regular vmalloc. The module loader code will + * create jump tables to handle long jumps */ + if (!ptr) + return vmalloc(size); + + return ptr; +#endif +} + +static inline bool is_phys_addr(void *ptr) +{ +#ifdef CONFIG_64BIT + return (KSEGX((unsigned long)ptr) == CKSEG0); +#else + return (KSEGX(ptr) == KSEG0); #endif } /* Free memory returned from module_alloc */ void module_free(struct module *mod, void *module_region) { - vfree(module_region); + if (is_phys_addr(module_region)) { + if (mod->module_init == module_region) + free_phys(module_region, mod->init_size); + else if (mod->module_core == module_region) + free_phys(module_region, mod->core_size); + else + BUG(); + } else { + vfree(module_region); + } /* FIXME: If module_region == mod->init_region, trim exception table entries. */ } @@ -75,6 +214,24 @@ int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, char *secstrings, struct module *mod) { + unsigned int symindex = 0; + unsigned int core_size, init_size; + int i; + + for (i = 1; i < hdr->e_shnum; i++) + if (sechdrs[i].sh_type == SHT_SYMTAB) + symindex = i; + + core_size = get_plt_size(hdr, sechdrs, secstrings, symindex, false); + init_size = get_plt_size(hdr, sechdrs, secstrings, symindex, true); + + mod->arch.core_plt_offset = 0; + mod->arch.core_plt_size = core_size; + mod->arch.init_plt_offset = core_size; + mod->arch.plt_tbl = kmalloc(core_size + init_size, GFP_KERNEL); + if (!mod->arch.plt_tbl) + return -ENOMEM; + return 0; } @@ -97,27 +254,41 @@ return 0; } -static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v) +static Elf_Addr add_plt_entry_to(unsigned *plt_offset, + void *start, Elf_Addr v) { - if (v % 4) { - printk(KERN_ERR "module %s: dangerous relocation\n", me->name); - return -ENOEXEC; - } + unsigned *tramp = start + *plt_offset; - if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) { - printk(KERN_ERR - "module %s: relocation overflow\n", - me->name); - return -ENOEXEC; - } + *plt_offset += 4 * sizeof(int); + + /* adjust carry for addiu */ + if (v & 0x00008000) + v += 0x10000; + + tramp[0] = 0x3c190000 | (v >> 16); /* lui t9, hi16 */ + tramp[1] = 0x27390000 | (v & 0xffff); /* addiu t9, t9, lo16 */ + tramp[2] = 0x03200008; /* jr t9 */ + tramp[3] = 0x00000000; /* nop */ - *location = (*location & ~0x03ffffff) | - ((*location + (v >> 2)) & 0x03ffffff); + return (Elf_Addr) tramp; +} + +static Elf_Addr add_plt_entry(struct module *me, void *location, Elf_Addr v) +{ + if (location >= me->module_core && + location < me->module_core + me->core_size) + return add_plt_entry_to(&me->arch.core_plt_offset, + me->arch.plt_tbl, v); + + if (location >= me->module_init && + location < me->module_init + me->init_size) + return add_plt_entry_to(&me->arch.init_plt_offset, + me->arch.plt_tbl, v); return 0; } -static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v) +static int set_r_mips_26(struct module *me, u32 *location, u32 ofs, Elf_Addr v) { if (v % 4) { printk(KERN_ERR "module %s: dangerous relocation\n", me->name); @@ -125,17 +296,31 @@ } if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) { - printk(KERN_ERR + v = add_plt_entry(me, location, v + (ofs << 2)); + if (!v) { + printk(KERN_ERR "module %s: relocation overflow\n", me->name); - return -ENOEXEC; + return -ENOEXEC; + } + ofs = 0; } - *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff); + *location = (*location & ~0x03ffffff) | ((ofs + (v >> 2)) & 0x03ffffff); return 0; } +static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v) +{ + return set_r_mips_26(me, location, *location & 0x03ffffff, v); +} + +static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v) +{ + return set_r_mips_26(me, location, 0, v); +} + static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v) { struct mips_hi16 *n; @@ -400,11 +585,23 @@ list_add(&me->arch.dbe_list, &dbe_list); spin_unlock_irq(&dbe_lock); } + + /* Get rid of the fixup trampoline if we're running the module + * from physically mapped address space */ + if (me->arch.core_plt_offset == 0 && + me->arch.init_plt_offset == me->arch.core_plt_size && + is_phys_addr(me->module_core)) { + kfree(me->arch.plt_tbl); + me->arch.plt_tbl = NULL; + } + return 0; } void module_arch_cleanup(struct module *mod) { + if (mod->arch.plt_tbl) + kfree(mod->arch.plt_tbl); spin_lock_irq(&dbe_lock); list_del(&mod->arch.dbe_list); spin_unlock_irq(&dbe_lock);