/* binfmt_elf_fdpic.c: FDPIC ELF binary format * * Copyright (C) 2003, 2004 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * Derived from binfmt_elf.c * * 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. */ #include <linux/module.h> #include <linux/fs.h> #include <linux/stat.h> #include <linux/sched.h> #include <linux/mm.h> #include <linux/mman.h> #include <linux/errno.h> #include <linux/signal.h> #include <linux/binfmts.h> #include <linux/string.h> #include <linux/file.h> #include <linux/fcntl.h> #include <linux/slab.h> #include <linux/highmem.h> #include <linux/personality.h> #include <linux/ptrace.h> #include <linux/init.h> #include <linux/smp_lock.h> #include <linux/elf.h> #include <linux/elf-fdpic.h> #include <linux/elfcore.h> #include <asm/uaccess.h> #include <asm/param.h> #include <asm/pgalloc.h> typedef char *elf_caddr_t; #ifndef elf_addr_t #define elf_addr_t unsigned long #endif #if 0 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) #else #define kdebug(fmt, ...) do {} while(0) #endif MODULE_LICENSE("GPL"); static int load_elf_fdpic_binary(struct linux_binprm *bprm, struct pt_regs *regs); //static int load_elf_fdpic_library(struct file *); static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, struct file *file); static int elf_fdpic_map_file(struct elf_fdpic_params *params, struct file *file, struct mm_struct *mm, const char *what); static int create_elf_fdpic_tables(struct linux_binprm *bprm, struct mm_struct *mm, struct elf_fdpic_params *exec_params, struct elf_fdpic_params *interp_params); #ifndef CONFIG_MMU static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, unsigned long *_sp); static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *params, struct file *file, struct mm_struct *mm); #endif static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, struct file *file, struct mm_struct *mm); static struct linux_binfmt elf_fdpic_format = { .module = THIS_MODULE, .load_binary = load_elf_fdpic_binary, // .load_shlib = load_elf_fdpic_library, // .core_dump = elf_fdpic_core_dump, .min_coredump = ELF_EXEC_PAGESIZE, }; static int __init init_elf_fdpic_binfmt(void) { return register_binfmt(&elf_fdpic_format); } static void __exit exit_elf_fdpic_binfmt(void) { unregister_binfmt(&elf_fdpic_format); } module_init(init_elf_fdpic_binfmt) module_exit(exit_elf_fdpic_binfmt) static int is_elf_fdpic(struct elfhdr *hdr, struct file *file) { if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0) return 0; if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) return 0; if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr)) return 0; if (!file->f_op || !file->f_op->mmap) return 0; return 1; } /*****************************************************************************/ /* * read the program headers table into memory */ static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, struct file *file) { struct elf32_phdr *phdr; unsigned long size; int retval, loop; if (params->hdr.e_phentsize != sizeof(struct elf_phdr)) return -ENOMEM; if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr)) return -ENOMEM; size = params->hdr.e_phnum * sizeof(struct elf_phdr); params->phdrs = kmalloc(size, GFP_KERNEL); if (!params->phdrs) return -ENOMEM; retval = kernel_read(file, params->hdr.e_phoff, (char *) params->phdrs, size); if (retval < 0) return retval; /* determine stack size for this binary */ phdr = params->phdrs; for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { if (phdr->p_type != PT_GNU_STACK) continue; if (phdr->p_flags & PF_X) params->flags |= ELF_FDPIC_FLAG_EXEC_STACK; else params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK; params->stack_size = phdr->p_memsz; break; } return 0; } /* end elf_fdpic_fetch_phdrs() */ /*****************************************************************************/ /* * load an fdpic binary into various bits of memory */ static int load_elf_fdpic_binary(struct linux_binprm *bprm, struct pt_regs *regs) { struct elf_fdpic_params exec_params, interp_params; struct elf_phdr *phdr; unsigned long stack_size; struct file *interpreter = NULL; /* to shut gcc up */ char *interpreter_name = NULL; int executable_stack; int retval, i; memset(&exec_params, 0, sizeof(exec_params)); memset(&interp_params, 0, sizeof(interp_params)); exec_params.hdr = *(struct elfhdr *) bprm->buf; exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE; /* check that this is a binary we know how to deal with */ retval = -ENOEXEC; if (!is_elf_fdpic(&exec_params.hdr, bprm->file)) goto error; /* read the program header table */ retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file); if (retval < 0) goto error; /* scan for a program header that specifies an interpreter */ phdr = exec_params.phdrs; for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) { switch (phdr->p_type) { case PT_INTERP: retval = -ENOMEM; if (phdr->p_filesz > PATH_MAX) goto error; retval = -ENOENT; if (phdr->p_filesz < 2) goto error; /* read the name of the interpreter into memory */ interpreter_name = (char *) kmalloc(phdr->p_filesz, GFP_KERNEL); if (!interpreter_name) goto error; retval = kernel_read(bprm->file, phdr->p_offset, interpreter_name, phdr->p_filesz); if (retval < 0) goto error; retval = -ENOENT; if (interpreter_name[phdr->p_filesz - 1] != '\0') goto error; kdebug("Using ELF interpreter %s", interpreter_name); /* replace the program with the interpreter */ interpreter = open_exec(interpreter_name); retval = PTR_ERR(interpreter); if (IS_ERR(interpreter)) { interpreter = NULL; goto error; } retval = kernel_read(interpreter, 0, bprm->buf, BINPRM_BUF_SIZE); if (retval < 0) goto error; interp_params.hdr = *((struct elfhdr *) bprm->buf); break; case PT_LOAD: #ifdef CONFIG_MMU if (exec_params.load_addr == 0) exec_params.load_addr = phdr->p_vaddr; #endif break; } } if (elf_check_const_displacement(&exec_params.hdr)) exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; /* perform insanity checks on the interpreter */ if (interpreter_name) { retval = -ELIBBAD; if (!is_elf_fdpic(&interp_params.hdr, interpreter)) goto error; interp_params.flags = ELF_FDPIC_FLAG_PRESENT; /* read the interpreter's program header table */ retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter); if (retval < 0) goto error; } stack_size = exec_params.stack_size; if (stack_size < interp_params.stack_size) stack_size = interp_params.stack_size; if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) executable_stack = EXSTACK_ENABLE_X; else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) executable_stack = EXSTACK_DISABLE_X; else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) executable_stack = EXSTACK_ENABLE_X; else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) executable_stack = EXSTACK_DISABLE_X; else executable_stack = EXSTACK_DEFAULT; retval = -ENOEXEC; if (stack_size == 0) goto error; if (elf_check_const_displacement(&interp_params.hdr)) interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; /* flush all traces of the currently running executable */ retval = flush_old_exec(bprm); if (retval) goto error; /* there's now no turning back... the old userspace image is dead, * defunct, deceased, etc. after this point we have to exit via * error_kill */ set_personality(PER_LINUX_FDPIC); set_binfmt(&elf_fdpic_format); current->mm->start_code = 0; current->mm->end_code = 0; current->mm->start_stack = 0; current->mm->start_data = 0; current->mm->end_data = 0; current->mm->context.exec_fdpic_loadmap = 0; current->mm->context.interp_fdpic_loadmap = 0; current->flags &= ~PF_FORKNOEXEC; #ifdef CONFIG_MMU elf_fdpic_arch_lay_out_mm(&exec_params, &interp_params, ¤t->mm->start_stack, ¤t->mm->start_brk); retval = setup_arg_pages(bprm, current->mm->start_stack, executable_stack); if (retval < 0) { send_sig(SIGKILL, current, 0); goto error_kill; } #endif /* load the executable and interpreter into memory */ retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, "executable"); if (retval < 0) goto error_kill; if (interpreter_name) { retval = elf_fdpic_map_file(&interp_params, interpreter, current->mm, "interpreter"); if (retval < 0) { printk(KERN_ERR "Unable to load interpreter\n"); goto error_kill; } allow_write_access(interpreter); fput(interpreter); interpreter = NULL; } #ifdef CONFIG_MMU if (!current->mm->start_brk) current->mm->start_brk = current->mm->end_data; current->mm->brk = current->mm->start_brk = PAGE_ALIGN(current->mm->start_brk); #else /* create a stack and brk area big enough for everyone * - the brk heap starts at the bottom and works up * - the stack starts at the top and works down */ stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; if (stack_size < PAGE_SIZE * 2) stack_size = PAGE_SIZE * 2; down_write(¤t->mm->mmap_sem); current->mm->start_brk = do_mmap(NULL, 0, stack_size, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANON | MAP_GROWSDOWN, 0); if (IS_ERR((void *) current->mm->start_brk)) { up_write(¤t->mm->mmap_sem); retval = current->mm->start_brk; current->mm->start_brk = 0; goto error_kill; } if (do_mremap(current->mm->start_brk, stack_size, ksize((char *) current->mm->start_brk), 0, 0 ) == current->mm->start_brk ) stack_size = ksize((char *) current->mm->start_brk); up_write(¤t->mm->mmap_sem); current->mm->brk = current->mm->start_brk; current->mm->context.end_brk = current->mm->start_brk; current->mm->context.end_brk += (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0; current->mm->start_stack = current->mm->start_brk + stack_size; #endif compute_creds(bprm); current->flags &= ~PF_FORKNOEXEC; if (create_elf_fdpic_tables(bprm, current->mm, &exec_params, &interp_params) < 0) goto error_kill; kdebug("- start_code %lx", (long) current->mm->start_code); kdebug("- end_code %lx", (long) current->mm->end_code); kdebug("- start_data %lx", (long) current->mm->start_data); kdebug("- end_data %lx", (long) current->mm->end_data); kdebug("- start_brk %lx", (long) current->mm->start_brk); kdebug("- brk %lx", (long) current->mm->brk); kdebug("- start_stack %lx", (long) current->mm->start_stack); #ifdef ELF_FDPIC_PLAT_INIT /* * The ABI may specify that certain registers be set up in special * ways (on i386 %edx is the address of a DT_FINI function, for * example. This macro performs whatever initialization to * the regs structure is required. */ ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr, interp_params.dynamic_addr ?: exec_params.dynamic_addr ); #endif /* everything is now ready... get the userspace context ready to roll */ start_thread(regs, interp_params.entry_addr ?: exec_params.entry_addr, current->mm->start_stack); if (unlikely(current->ptrace & PT_PTRACED)) { if (current->ptrace & PT_TRACE_EXEC) ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP); else send_sig(SIGTRAP, current, 0); } retval = 0; error: if (interpreter) { allow_write_access(interpreter); fput(interpreter); } kfree(interpreter_name); kfree(exec_params.phdrs); kfree(exec_params.loadmap); kfree(interp_params.phdrs); kfree(interp_params.loadmap); return retval; /* unrecoverable error - kill the process */ error_kill: send_sig(SIGSEGV, current, 0); goto error; } /* end load_elf_fdpic_binary() */ /*****************************************************************************/ /* * present useful information to the program */ static int create_elf_fdpic_tables(struct linux_binprm *bprm, struct mm_struct *mm, struct elf_fdpic_params *exec_params, struct elf_fdpic_params *interp_params) { unsigned long sp, csp, nitems; elf_caddr_t *argv, *envp; size_t platform_len = 0, len; char *k_platform, *u_platform, *p; long hwcap; int loop; /* we're going to shovel a whole load of stuff onto the stack */ #ifdef CONFIG_MMU sp = bprm->p; #else sp = mm->start_stack; /* stack the program arguments and environment */ if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0) return -EFAULT; #endif /* get hold of platform and hardware capabilities masks for the machine * we are running on. In some cases (Sparc), this info is impossible * to get, in others (i386) it is merely difficult. */ hwcap = ELF_HWCAP; k_platform = ELF_PLATFORM; if (k_platform) { platform_len = strlen(k_platform) + 1; sp -= platform_len; if (__copy_to_user(u_platform, k_platform, platform_len) != 0) return -EFAULT; } u_platform = (char *) sp; #if defined(__i386__) && defined(CONFIG_SMP) /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions * by the processes running on the same package. One thing we can do * is to shuffle the initial stack for them. * * the conditionals here are unneeded, but kept in to make the * code behaviour the same as pre change unless we have hyperthreaded * processors. This keeps Mr Marcelo Person happier but should be * removed for 2.5 */ if (smp_num_siblings > 1) sp = sp - ((current->pid % 64) << 7); #endif sp &= ~7UL; /* stack the load map(s) */ len = sizeof(struct elf32_fdpic_loadmap); len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; sp = (sp - len) & ~7UL; exec_params->map_addr = sp; if (copy_to_user((void *) sp, exec_params->loadmap, len) != 0) return -EFAULT; current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; if (interp_params->loadmap) { len = sizeof(struct elf32_fdpic_loadmap); len += sizeof(struct elf32_fdpic_loadseg) * interp_params->loadmap->nsegs; sp = (sp - len) & ~7UL; interp_params->map_addr = sp; if (copy_to_user((void *) sp, interp_params->loadmap, len) != 0) return -EFAULT; current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; } /* force 16 byte _final_ alignment here for generality */ #define DLINFO_ITEMS 13 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0); #ifdef DLINFO_ARCH_ITEMS nitems += DLINFO_ARCH_ITEMS; #endif csp = sp; sp -= nitems * 2 * sizeof(unsigned long); sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ sp -= 1 * sizeof(unsigned long); /* argc */ csp -= sp & 15UL; sp -= sp & 15UL; /* put the ELF interpreter info on the stack */ #define NEW_AUX_ENT(nr, id, val) \ do { \ struct { unsigned long _id, _val; } *ent = (void *) csp; \ __put_user((id), &ent[nr]._id); \ __put_user((val), &ent[nr]._val); \ } while (0) csp -= 2 * sizeof(unsigned long); NEW_AUX_ENT(0, AT_NULL, 0); if (k_platform) { csp -= 2 * sizeof(unsigned long); NEW_AUX_ENT(0, AT_PLATFORM, (elf_addr_t)(unsigned long) u_platform); } csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); NEW_AUX_ENT( 0, AT_HWCAP, hwcap); NEW_AUX_ENT( 1, AT_PAGESZ, PAGE_SIZE); NEW_AUX_ENT( 2, AT_CLKTCK, CLOCKS_PER_SEC); NEW_AUX_ENT( 3, AT_PHDR, exec_params->ph_addr); NEW_AUX_ENT( 4, AT_PHENT, sizeof(struct elf_phdr)); NEW_AUX_ENT( 5, AT_PHNUM, exec_params->hdr.e_phnum); NEW_AUX_ENT( 6, AT_BASE, interp_params->elfhdr_addr); NEW_AUX_ENT( 7, AT_FLAGS, 0); NEW_AUX_ENT( 8, AT_ENTRY, exec_params->entry_addr); NEW_AUX_ENT( 9, AT_UID, (elf_addr_t) current->uid); NEW_AUX_ENT(10, AT_EUID, (elf_addr_t) current->euid); NEW_AUX_ENT(11, AT_GID, (elf_addr_t) current->gid); NEW_AUX_ENT(12, AT_EGID, (elf_addr_t) current->egid); #ifdef ARCH_DLINFO /* ARCH_DLINFO must come last so platform specific code can enforce * special alignment requirements on the AUXV if necessary (eg. PPC). */ ARCH_DLINFO; #endif #undef NEW_AUX_ENT /* allocate room for argv[] and envv[] */ csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); envp = (elf_caddr_t *) csp; csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); argv = (elf_caddr_t *) csp; /* stack argc */ csp -= sizeof(unsigned long); __put_user(bprm->argc, (unsigned long *) csp); if (csp != sp) BUG(); /* fill in the argv[] array */ #ifdef CONFIG_MMU current->mm->arg_start = bprm->p; #else current->mm->arg_start = current->mm->start_stack - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); #endif p = (char *) current->mm->arg_start; for (loop = bprm->argc; loop > 0; loop--) { __put_user((elf_caddr_t) p, argv++); len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES); if (!len || len > PAGE_SIZE * MAX_ARG_PAGES) return -EINVAL; p += len; } __put_user(NULL, argv); current->mm->arg_end = (unsigned long) p; /* fill in the envv[] array */ current->mm->env_start = (unsigned long) p; for (loop = bprm->envc; loop > 0; loop--) { __put_user((elf_caddr_t)(unsigned long) p, envp++); len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES); if (!len || len > PAGE_SIZE * MAX_ARG_PAGES) return -EINVAL; p += len; } __put_user(NULL, envp); current->mm->env_end = (unsigned long) p; mm->start_stack = (unsigned long) sp; return 0; } /* end create_elf_fdpic_tables() */ /*****************************************************************************/ /* * transfer the program arguments and environment from the holding pages onto * the stack */ #ifndef CONFIG_MMU static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, unsigned long *_sp) { unsigned long index, stop, sp; char *src; int ret = 0; stop = bprm->p >> PAGE_SHIFT; sp = *_sp; for (index = MAX_ARG_PAGES - 1; index >= stop; index--) { src = kmap(bprm->page[index]); sp -= PAGE_SIZE; if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0) ret = -EFAULT; kunmap(bprm->page[index]); if (ret < 0) goto out; } *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15; out: return ret; } /* end elf_fdpic_transfer_args_to_stack() */ #endif /*****************************************************************************/ /* * load the appropriate binary image (executable or interpreter) into memory * - we assume no MMU is available * - if no other PIC bits are set in params->hdr->e_flags * - we assume that the LOADable segments in the binary are independently relocatable * - we assume R/O executable segments are shareable * - else * - we assume the loadable parts of the image to require fixed displacement * - the image is not shareable */ static int elf_fdpic_map_file(struct elf_fdpic_params *params, struct file *file, struct mm_struct *mm, const char *what) { struct elf32_fdpic_loadmap *loadmap; #ifdef CONFIG_MMU struct elf32_fdpic_loadseg *mseg; #endif struct elf32_fdpic_loadseg *seg; struct elf32_phdr *phdr; unsigned long load_addr, stop; unsigned nloads, tmp; size_t size; int loop, ret; /* allocate a load map table */ nloads = 0; for (loop = 0; loop < params->hdr.e_phnum; loop++) if (params->phdrs[loop].p_type == PT_LOAD) nloads++; if (nloads == 0) return -ELIBBAD; size = sizeof(*loadmap) + nloads * sizeof(*seg); loadmap = kmalloc(size, GFP_KERNEL); if (!loadmap) return -ENOMEM; params->loadmap = loadmap; memset(loadmap, 0, size); loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; loadmap->nsegs = nloads; load_addr = params->load_addr; seg = loadmap->segs; /* map the requested LOADs into the memory space */ switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { case ELF_FDPIC_FLAG_CONSTDISP: case ELF_FDPIC_FLAG_CONTIGUOUS: #ifndef CONFIG_MMU ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); if (ret < 0) return ret; break; #endif default: ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); if (ret < 0) return ret; break; } /* map the entry point */ if (params->hdr.e_entry) { seg = loadmap->segs; for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { if (params->hdr.e_entry >= seg->p_vaddr && params->hdr.e_entry < seg->p_vaddr + seg->p_memsz ) { params->entry_addr = (params->hdr.e_entry - seg->p_vaddr) + seg->addr; break; } } } /* determine where the program header table has wound up if mapped */ stop = params->hdr.e_phoff + params->hdr.e_phnum * sizeof (struct elf_phdr); phdr = params->phdrs; for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { if (phdr->p_type != PT_LOAD) continue; if (phdr->p_offset > params->hdr.e_phoff || phdr->p_offset + phdr->p_filesz < stop) continue; seg = loadmap->segs; for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { if (phdr->p_vaddr >= seg->p_vaddr && phdr->p_vaddr + phdr->p_filesz <= seg->p_vaddr + seg->p_memsz ) { params->ph_addr = (phdr->p_vaddr - seg->p_vaddr) + seg->addr + params->hdr.e_phoff - phdr->p_offset; break; } } break; } /* determine where the dynamic section has wound up if there is one */ phdr = params->phdrs; for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { if (phdr->p_type != PT_DYNAMIC) continue; seg = loadmap->segs; for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { if (phdr->p_vaddr >= seg->p_vaddr && phdr->p_vaddr + phdr->p_memsz <= seg->p_vaddr + seg->p_memsz ) { params->dynamic_addr = (phdr->p_vaddr - seg->p_vaddr) + seg->addr; /* check the dynamic section contains at least one item, and that * the last item is a NULL entry */ if (phdr->p_memsz == 0 || phdr->p_memsz % sizeof(Elf32_Dyn) != 0) goto dynamic_error; tmp = phdr->p_memsz / sizeof(Elf32_Dyn); if (((Elf32_Dyn *) params->dynamic_addr)[tmp - 1].d_tag != 0) goto dynamic_error; break; } } break; } /* now elide adjacent segments in the load map on MMU linux * - on uClinux the holes between may actually be filled with system stuff or stuff from * other processes */ #ifdef CONFIG_MMU nloads = loadmap->nsegs; mseg = loadmap->segs; seg = mseg + 1; for (loop = 1; loop < nloads; loop++) { /* see if we have a candidate for merging */ if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); if (load_addr == (seg->addr & PAGE_MASK)) { mseg->p_memsz += load_addr - (mseg->addr + mseg->p_memsz); mseg->p_memsz += seg->addr & ~PAGE_MASK; mseg->p_memsz += seg->p_memsz; loadmap->nsegs--; continue; } } mseg++; if (mseg != seg) *mseg = *seg; } #endif kdebug("Mapped Object [%s]:", what); kdebug("- elfhdr : %lx", params->elfhdr_addr); kdebug("- entry : %lx", params->entry_addr); kdebug("- PHDR[] : %lx", params->ph_addr); kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); seg = loadmap->segs; for (loop = 0; loop < loadmap->nsegs; loop++, seg++) kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", loop, seg->addr, seg->addr + seg->p_memsz - 1, seg->p_vaddr, seg->p_memsz); return 0; dynamic_error: printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", what, file->f_dentry->d_inode->i_ino); return -ELIBBAD; } /* end elf_fdpic_map_file() */ /*****************************************************************************/ /* * map a file with constant displacement under uClinux */ #ifndef CONFIG_MMU static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *params, struct file *file, struct mm_struct *mm) { struct elf32_fdpic_loadseg *seg; struct elf32_phdr *phdr; unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; loff_t fpos; int loop, ret; load_addr = params->load_addr; seg = params->loadmap->segs; /* determine the bounds of the contiguous overall allocation we must make */ phdr = params->phdrs; for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { if (params->phdrs[loop].p_type != PT_LOAD) continue; if (base > phdr->p_vaddr) base = phdr->p_vaddr; if (top < phdr->p_vaddr + phdr->p_memsz) top = phdr->p_vaddr + phdr->p_memsz; } /* allocate one big anon block for everything */ mflags = MAP_PRIVATE; if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) mflags |= MAP_EXECUTABLE; down_write(&mm->mmap_sem); maddr = do_mmap(NULL, load_addr, top - base, PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); up_write(&mm->mmap_sem); if (IS_ERR((void *) maddr)) return (int) maddr; if (load_addr != 0) load_addr += PAGE_ALIGN(top - base); /* and then load the file segments into it */ phdr = params->phdrs; for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { if (params->phdrs[loop].p_type != PT_LOAD) continue; fpos = phdr->p_offset; seg->addr = maddr + (phdr->p_vaddr - base); seg->p_vaddr = phdr->p_vaddr; seg->p_memsz = phdr->p_memsz; ret = file->f_op->read(file, (void *) seg->addr, phdr->p_filesz, &fpos); if (ret < 0) return ret; /* map the ELF header address if in this segment */ if (phdr->p_offset == 0) params->elfhdr_addr = seg->addr; /* clear any space allocated but not loaded */ if (phdr->p_filesz < phdr->p_memsz) clear_user((void *) (seg->addr + phdr->p_filesz), phdr->p_memsz - phdr->p_filesz); if (mm) { if (phdr->p_flags & PF_X) { mm->start_code = seg->addr; mm->end_code = seg->addr + phdr->p_memsz; } else if (!mm->start_data) { mm->start_data = seg->addr; #ifndef CONFIG_MMU mm->end_data = seg->addr + phdr->p_memsz; #endif } #ifdef CONFIG_MMU if (seg->addr + phdr->p_memsz > mm->end_data) mm->end_data = seg->addr + phdr->p_memsz; #endif } seg++; } return 0; } /* end elf_fdpic_map_file_constdisp_on_uclinux() */ #endif /*****************************************************************************/ /* * map a binary by direct mmap() of the individual PT_LOAD segments */ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, struct file *file, struct mm_struct *mm) { struct elf32_fdpic_loadseg *seg; struct elf32_phdr *phdr; unsigned long load_addr, delta_vaddr; int loop, dvset; load_addr = params->load_addr; delta_vaddr = 0; dvset = 0; seg = params->loadmap->segs; /* deal with each load segment separately */ phdr = params->phdrs; for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { unsigned long maddr, disp, excess, excess1; int prot = 0, flags; if (phdr->p_type != PT_LOAD) continue; kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", (unsigned long) phdr->p_vaddr, (unsigned long) phdr->p_offset, (unsigned long) phdr->p_filesz, (unsigned long) phdr->p_memsz); /* determine the mapping parameters */ if (phdr->p_flags & PF_R) prot |= PROT_READ; if (phdr->p_flags & PF_W) prot |= PROT_WRITE; if (phdr->p_flags & PF_X) prot |= PROT_EXEC; flags = MAP_PRIVATE | MAP_DENYWRITE; if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) flags |= MAP_EXECUTABLE; maddr = 0; switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { case ELF_FDPIC_FLAG_INDEPENDENT: /* PT_LOADs are independently locatable */ break; case ELF_FDPIC_FLAG_HONOURVADDR: /* the specified virtual address must be honoured */ maddr = phdr->p_vaddr; flags |= MAP_FIXED; break; case ELF_FDPIC_FLAG_CONSTDISP: /* constant displacement * - can be mapped anywhere, but must be mapped as a unit */ if (!dvset) { maddr = load_addr; delta_vaddr = phdr->p_vaddr; dvset = 1; } else { maddr = load_addr + phdr->p_vaddr - delta_vaddr; flags |= MAP_FIXED; } break; case ELF_FDPIC_FLAG_CONTIGUOUS: /* contiguity handled later */ break; default: BUG(); } maddr &= PAGE_MASK; /* create the mapping */ disp = phdr->p_vaddr & ~PAGE_MASK; down_write(&mm->mmap_sem); maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, phdr->p_offset - disp); up_write(&mm->mmap_sem); kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", loop, phdr->p_memsz + disp, prot, flags, phdr->p_offset - disp, maddr); if (IS_ERR((void *) maddr)) return (int) maddr; if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == ELF_FDPIC_FLAG_CONTIGUOUS) load_addr += PAGE_ALIGN(phdr->p_memsz + disp); seg->addr = maddr + disp; seg->p_vaddr = phdr->p_vaddr; seg->p_memsz = phdr->p_memsz; /* map the ELF header address if in this segment */ if (phdr->p_offset == 0) params->elfhdr_addr = seg->addr; /* clear the bit between beginning of mapping and beginning of PT_LOAD */ if (prot & PROT_WRITE && disp > 0) { kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); clear_user((void *) maddr, disp); maddr += disp; } /* clear any space allocated but not loaded * - on uClinux we can just clear the lot * - on MMU linux we'll get a SIGBUS beyond the last page * extant in the file */ excess = phdr->p_memsz - phdr->p_filesz; excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); #ifdef CONFIG_MMU if (excess > excess1) { unsigned long xaddr = maddr + phdr->p_filesz + excess1; unsigned long xmaddr; flags |= MAP_FIXED | MAP_ANONYMOUS; down_write(&mm->mmap_sem); xmaddr = do_mmap(NULL, xaddr, excess - excess1, prot, flags, 0); up_write(&mm->mmap_sem); kdebug("mmap[%d] <anon>" " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", loop, xaddr, excess - excess1, prot, flags, xmaddr); if (xmaddr != xaddr) return -ENOMEM; } if (prot & PROT_WRITE && excess1 > 0) { kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr + phdr->p_filesz, excess1); clear_user((void *) maddr + phdr->p_filesz, excess1); } #else if (excess > 0) { kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr + phdr->p_filesz, excess); clear_user((void *) maddr + phdr->p_filesz, excess); } #endif if (mm) { if (phdr->p_flags & PF_X) { mm->start_code = maddr; mm->end_code = maddr + phdr->p_memsz; } else if (!mm->start_data) { mm->start_data = maddr; mm->end_data = maddr + phdr->p_memsz; } } seg++; } return 0; } /* end elf_fdpic_map_file_by_direct_mmap() */