diff options
Diffstat (limited to 'fs/binfmt_elf_fdpic.c')
| -rw-r--r-- | fs/binfmt_elf_fdpic.c | 1101 |
1 files changed, 1101 insertions, 0 deletions
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c new file mode 100644 index 000000000000..134c9c0d1f54 --- /dev/null +++ b/fs/binfmt_elf_fdpic.c @@ -0,0 +1,1101 @@ +/* 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); +#endif + + /* do this so that we can load the interpreter, if need be + * - we will change some of these later + */ + set_mm_counter(current->mm, rss, 0); + +#ifdef CONFIG_MMU + 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); + } + if (interpreter_name) + kfree(interpreter_name); + if (exec_params.phdrs) + kfree(exec_params.phdrs); + if (exec_params.loadmap) + kfree(exec_params.loadmap); + if (interp_params.phdrs) + kfree(interp_params.phdrs); + if (interp_params.loadmap) + 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() */ |