diff options
Diffstat (limited to 'fs/binfmt_elf_fdpic.c')
| -rw-r--r-- | fs/binfmt_elf_fdpic.c | 1863 |
1 files changed, 1863 insertions, 0 deletions
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c new file mode 100644 index 00000000..d390a0ff --- /dev/null +++ b/fs/binfmt_elf_fdpic.c @@ -0,0 +1,1863 @@ +/* binfmt_elf_fdpic.c: FDPIC ELF binary format + * + * Copyright (C) 2003, 2004, 2006 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/pagemap.h> +#include <linux/security.h> +#include <linux/highmem.h> +#include <linux/highuid.h> +#include <linux/personality.h> +#include <linux/ptrace.h> +#include <linux/init.h> +#include <linux/elf.h> +#include <linux/elf-fdpic.h> +#include <linux/elfcore.h> +#include <linux/coredump.h> + +#include <asm/uaccess.h> +#include <asm/param.h> +#include <asm/pgalloc.h> +#include <asm/exec.h> + +typedef char *elf_caddr_t; + +#if 0 +#define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) +#else +#define kdebug(fmt, ...) do {} while(0) +#endif + +#if 0 +#define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) +#else +#define kdcore(fmt, ...) do {} while(0) +#endif + +MODULE_LICENSE("GPL"); + +static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *); +static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *); +static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *, + struct mm_struct *, const char *); + +static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *, + struct elf_fdpic_params *, + struct elf_fdpic_params *); + +#ifndef CONFIG_MMU +static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *, + unsigned long *); +static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *, + struct file *, + struct mm_struct *); +#endif + +static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *, + struct file *, struct mm_struct *); + +#ifdef CONFIG_ELF_CORE +static int elf_fdpic_core_dump(struct coredump_params *cprm); +#endif + +static struct linux_binfmt elf_fdpic_format = { + .module = THIS_MODULE, + .load_binary = load_elf_fdpic_binary, +#ifdef CONFIG_ELF_CORE + .core_dump = elf_fdpic_core_dump, +#endif + .min_coredump = ELF_EXEC_PAGESIZE, +}; + +static int __init init_elf_fdpic_binfmt(void) +{ + register_binfmt(&elf_fdpic_format); + return 0; +} + +static void __exit exit_elf_fdpic_binfmt(void) +{ + unregister_binfmt(&elf_fdpic_format); +} + +core_initcall(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 (unlikely(retval != size)) + return retval < 0 ? retval : -ENOEXEC; + + /* 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; +} + +/*****************************************************************************/ +/* + * 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, entryaddr; +#ifdef ELF_FDPIC_PLAT_INIT + unsigned long dynaddr; +#endif +#ifndef CONFIG_MMU + unsigned long stack_prot; +#endif + struct file *interpreter = NULL; /* to shut gcc up */ + char *interpreter_name = NULL; + int executable_stack; + int retval, i; + + kdebug("____ LOAD %d ____", current->pid); + + 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 = 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 (unlikely(retval != phdr->p_filesz)) { + if (retval >= 0) + retval = -ENOEXEC; + 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; + } + + /* + * If the binary is not readable then enforce + * mm->dumpable = 0 regardless of the interpreter's + * permissions. + */ + would_dump(bprm, interpreter); + + retval = kernel_read(interpreter, 0, bprm->buf, + BINPRM_BUF_SIZE); + if (unlikely(retval != BINPRM_BUF_SIZE)) { + if (retval >= 0) + retval = -ENOEXEC; + 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 (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 + executable_stack = EXSTACK_DEFAULT; + + if (stack_size == 0) { + stack_size = interp_params.stack_size; + 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); + if (elf_read_implies_exec(&exec_params.hdr, executable_stack)) + current->personality |= READ_IMPLIES_EXEC; + + setup_new_exec(bprm); + + 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; + +#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; + + stack_prot = PROT_READ | PROT_WRITE; + if (executable_stack == EXSTACK_ENABLE_X || + (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC)) + stack_prot |= PROT_EXEC; + + current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot, + MAP_PRIVATE | MAP_ANONYMOUS | + MAP_UNINITIALIZED | MAP_GROWSDOWN, + 0); + + if (IS_ERR_VALUE(current->mm->start_brk)) { + retval = current->mm->start_brk; + current->mm->start_brk = 0; + goto error_kill; + } + + 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 + + install_exec_creds(bprm); + if (create_elf_fdpic_tables(bprm, current->mm, + &exec_params, &interp_params) < 0) + goto error_kill; + + kdebug("- start_code %lx", current->mm->start_code); + kdebug("- end_code %lx", current->mm->end_code); + kdebug("- start_data %lx", current->mm->start_data); + kdebug("- end_data %lx", current->mm->end_data); + kdebug("- start_brk %lx", current->mm->start_brk); + kdebug("- brk %lx", current->mm->brk); + kdebug("- start_stack %lx", 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. + */ + dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr; + ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr, + dynaddr); +#endif + + /* everything is now ready... get the userspace context ready to roll */ + entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; + start_thread(regs, entryaddr, current->mm->start_stack); + + 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; + +} + +/*****************************************************************************/ + +#ifndef ELF_BASE_PLATFORM +/* + * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. + * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value + * will be copied to the user stack in the same manner as AT_PLATFORM. + */ +#define ELF_BASE_PLATFORM NULL +#endif + +/* + * present useful information to the program by shovelling it onto the new + * process's stack + */ +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) +{ + const struct cred *cred = current_cred(); + unsigned long sp, csp, nitems; + elf_caddr_t __user *argv, *envp; + size_t platform_len = 0, len; + char *k_platform, *k_base_platform; + char __user *u_platform, *u_base_platform, *p; + long hwcap; + int loop; + int nr; /* reset for each csp adjustment */ + +#ifdef CONFIG_MMU + /* 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, so we give the architecture + * an opportunity to do so here. + */ + sp = arch_align_stack(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 + + hwcap = ELF_HWCAP; + + /* + * If this architecture has a platform capability string, copy it + * to userspace. In some cases (Sparc), this info is impossible + * for userspace to get any other way, in others (i386) it is + * merely difficult. + */ + k_platform = ELF_PLATFORM; + u_platform = NULL; + + if (k_platform) { + platform_len = strlen(k_platform) + 1; + sp -= platform_len; + u_platform = (char __user *) sp; + if (__copy_to_user(u_platform, k_platform, platform_len) != 0) + return -EFAULT; + } + + /* + * If this architecture has a "base" platform capability + * string, copy it to userspace. + */ + k_base_platform = ELF_BASE_PLATFORM; + u_base_platform = NULL; + + if (k_base_platform) { + platform_len = strlen(k_base_platform) + 1; + sp -= platform_len; + u_base_platform = (char __user *) sp; + if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) + return -EFAULT; + } + + 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 __user *) 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 __user *) 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 15 + + nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + + (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; + + if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) + nitems++; + + 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(id, val) \ + do { \ + struct { unsigned long _id, _val; } __user *ent; \ + \ + ent = (void __user *) csp; \ + __put_user((id), &ent[nr]._id); \ + __put_user((val), &ent[nr]._val); \ + nr++; \ + } while (0) + + nr = 0; + csp -= 2 * sizeof(unsigned long); + NEW_AUX_ENT(AT_NULL, 0); + if (k_platform) { + nr = 0; + csp -= 2 * sizeof(unsigned long); + NEW_AUX_ENT(AT_PLATFORM, + (elf_addr_t) (unsigned long) u_platform); + } + + if (k_base_platform) { + nr = 0; + csp -= 2 * sizeof(unsigned long); + NEW_AUX_ENT(AT_BASE_PLATFORM, + (elf_addr_t) (unsigned long) u_base_platform); + } + + if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { + nr = 0; + csp -= 2 * sizeof(unsigned long); + NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); + } + + nr = 0; + csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); + NEW_AUX_ENT(AT_HWCAP, hwcap); + NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); + NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); + NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); + NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); + NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); + NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); + NEW_AUX_ENT(AT_FLAGS, 0); + NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); + NEW_AUX_ENT(AT_UID, (elf_addr_t) cred->uid); + NEW_AUX_ENT(AT_EUID, (elf_addr_t) cred->euid); + NEW_AUX_ENT(AT_GID, (elf_addr_t) cred->gid); + NEW_AUX_ENT(AT_EGID, (elf_addr_t) cred->egid); + NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); + NEW_AUX_ENT(AT_EXECFN, bprm->exec); + +#ifdef ARCH_DLINFO + nr = 0; + csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long); + + /* 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 __user *) csp; + csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); + argv = (elf_caddr_t __user *) csp; + + /* stack argc */ + csp -= sizeof(unsigned long); + __put_user(bprm->argc, (unsigned long __user *) csp); + + BUG_ON(csp != sp); + + /* 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 __user *) current->mm->arg_start; + for (loop = bprm->argc; loop > 0; loop--) { + __put_user((elf_caddr_t) p, argv++); + len = strnlen_user(p, MAX_ARG_STRLEN); + if (!len || len > MAX_ARG_STRLEN) + 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, MAX_ARG_STRLEN); + if (!len || len > MAX_ARG_STRLEN) + return -EINVAL; + p += len; + } + __put_user(NULL, envp); + current->mm->env_end = (unsigned long) p; + + mm->start_stack = (unsigned long) sp; + return 0; +} + +/*****************************************************************************/ +/* + * 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; +} +#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 = kzalloc(size, GFP_KERNEL); + if (!loadmap) + return -ENOMEM; + + params->loadmap = loadmap; + + 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; + stop += 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_path.dentry->d_inode->i_ino); + return -ELIBBAD; +} + +/*****************************************************************************/ +/* + * 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; + + maddr = vm_mmap(NULL, load_addr, top - base, + PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); + if (IS_ERR_VALUE(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) { + if (clear_user((void *) (seg->addr + phdr->p_filesz), + phdr->p_memsz - phdr->p_filesz)) + return -EFAULT; + } + + if (mm) { + if (phdr->p_flags & PF_X) { + if (!mm->start_code) { + mm->start_code = seg->addr; + mm->end_code = seg->addr + + phdr->p_memsz; + } + } else if (!mm->start_data) { + mm->start_data = seg->addr; + mm->end_data = seg->addr + phdr->p_memsz; + } + } + + seg++; + } + + return 0; +} +#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; + maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, + phdr->p_offset - disp); + + 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_VALUE(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); + if (clear_user((void __user *) maddr, disp)) + return -EFAULT; + 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; + xmaddr = vm_mmap(NULL, xaddr, excess - excess1, + prot, flags, 0); + + 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); + if (clear_user((void __user *) maddr + phdr->p_filesz, + excess1)) + return -EFAULT; + } + +#else + if (excess > 0) { + kdebug("clear[%d] ad=%lx sz=%lx", + loop, maddr + phdr->p_filesz, excess); + if (clear_user((void *) maddr + phdr->p_filesz, excess)) + return -EFAULT; + } +#endif + + if (mm) { + if (phdr->p_flags & PF_X) { + if (!mm->start_code) { + 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; +} + +/*****************************************************************************/ +/* + * ELF-FDPIC core dumper + * + * Modelled on fs/exec.c:aout_core_dump() + * Jeremy Fitzhardinge <jeremy@sw.oz.au> + * + * Modelled on fs/binfmt_elf.c core dumper + */ +#ifdef CONFIG_ELF_CORE + +/* + * Decide whether a segment is worth dumping; default is yes to be + * sure (missing info is worse than too much; etc). + * Personally I'd include everything, and use the coredump limit... + * + * I think we should skip something. But I am not sure how. H.J. + */ +static int maydump(struct vm_area_struct *vma, unsigned long mm_flags) +{ + int dump_ok; + + /* Do not dump I/O mapped devices or special mappings */ + if (vma->vm_flags & (VM_IO | VM_RESERVED)) { + kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); + return 0; + } + + /* If we may not read the contents, don't allow us to dump + * them either. "dump_write()" can't handle it anyway. + */ + if (!(vma->vm_flags & VM_READ)) { + kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); + return 0; + } + + /* By default, dump shared memory if mapped from an anonymous file. */ + if (vma->vm_flags & VM_SHARED) { + if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) { + dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags); + kdcore("%08lx: %08lx: %s (share)", vma->vm_start, + vma->vm_flags, dump_ok ? "yes" : "no"); + return dump_ok; + } + + dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags); + kdcore("%08lx: %08lx: %s (share)", vma->vm_start, + vma->vm_flags, dump_ok ? "yes" : "no"); + return dump_ok; + } + +#ifdef CONFIG_MMU + /* By default, if it hasn't been written to, don't write it out */ + if (!vma->anon_vma) { + dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags); + kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start, + vma->vm_flags, dump_ok ? "yes" : "no"); + return dump_ok; + } +#endif + + dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags); + kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags, + dump_ok ? "yes" : "no"); + return dump_ok; +} + +/* An ELF note in memory */ +struct memelfnote +{ + const char *name; + int type; + unsigned int datasz; + void *data; +}; + +static int notesize(struct memelfnote *en) +{ + int sz; + + sz = sizeof(struct elf_note); + sz += roundup(strlen(en->name) + 1, 4); + sz += roundup(en->datasz, 4); + + return sz; +} + +/* #define DEBUG */ + +#define DUMP_WRITE(addr, nr, foffset) \ + do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0) + +static int alignfile(struct file *file, loff_t *foffset) +{ + static const char buf[4] = { 0, }; + DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset); + return 1; +} + +static int writenote(struct memelfnote *men, struct file *file, + loff_t *foffset) +{ + struct elf_note en; + en.n_namesz = strlen(men->name) + 1; + en.n_descsz = men->datasz; + en.n_type = men->type; + + DUMP_WRITE(&en, sizeof(en), foffset); + DUMP_WRITE(men->name, en.n_namesz, foffset); + if (!alignfile(file, foffset)) + return 0; + DUMP_WRITE(men->data, men->datasz, foffset); + if (!alignfile(file, foffset)) + return 0; + + return 1; +} +#undef DUMP_WRITE + +static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) +{ + memcpy(elf->e_ident, ELFMAG, SELFMAG); + elf->e_ident[EI_CLASS] = ELF_CLASS; + elf->e_ident[EI_DATA] = ELF_DATA; + elf->e_ident[EI_VERSION] = EV_CURRENT; + elf->e_ident[EI_OSABI] = ELF_OSABI; + memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); + + elf->e_type = ET_CORE; + elf->e_machine = ELF_ARCH; + elf->e_version = EV_CURRENT; + elf->e_entry = 0; + elf->e_phoff = sizeof(struct elfhdr); + elf->e_shoff = 0; + elf->e_flags = ELF_FDPIC_CORE_EFLAGS; + elf->e_ehsize = sizeof(struct elfhdr); + elf->e_phentsize = sizeof(struct elf_phdr); + elf->e_phnum = segs; + elf->e_shentsize = 0; + elf->e_shnum = 0; + elf->e_shstrndx = 0; + return; +} + +static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) +{ + phdr->p_type = PT_NOTE; + phdr->p_offset = offset; + phdr->p_vaddr = 0; + phdr->p_paddr = 0; + phdr->p_filesz = sz; + phdr->p_memsz = 0; + phdr->p_flags = 0; + phdr->p_align = 0; + return; +} + +static inline void fill_note(struct memelfnote *note, const char *name, int type, + unsigned int sz, void *data) +{ + note->name = name; + note->type = type; + note->datasz = sz; + note->data = data; + return; +} + +/* + * fill up all the fields in prstatus from the given task struct, except + * registers which need to be filled up separately. + */ +static void fill_prstatus(struct elf_prstatus *prstatus, + struct task_struct *p, long signr) +{ + prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; + prstatus->pr_sigpend = p->pending.signal.sig[0]; + prstatus->pr_sighold = p->blocked.sig[0]; + rcu_read_lock(); + prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); + rcu_read_unlock(); + prstatus->pr_pid = task_pid_vnr(p); + prstatus->pr_pgrp = task_pgrp_vnr(p); + prstatus->pr_sid = task_session_vnr(p); + if (thread_group_leader(p)) { + struct task_cputime cputime; + + /* + * This is the record for the group leader. It shows the + * group-wide total, not its individual thread total. + */ + thread_group_cputime(p, &cputime); + cputime_to_timeval(cputime.utime, &prstatus->pr_utime); + cputime_to_timeval(cputime.stime, &prstatus->pr_stime); + } else { + cputime_to_timeval(p->utime, &prstatus->pr_utime); + cputime_to_timeval(p->stime, &prstatus->pr_stime); + } + cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); + cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); + + prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; + prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; +} + +static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, + struct mm_struct *mm) +{ + const struct cred *cred; + unsigned int i, len; + + /* first copy the parameters from user space */ + memset(psinfo, 0, sizeof(struct elf_prpsinfo)); + + len = mm->arg_end - mm->arg_start; + if (len >= ELF_PRARGSZ) + len = ELF_PRARGSZ - 1; + if (copy_from_user(&psinfo->pr_psargs, + (const char __user *) mm->arg_start, len)) + return -EFAULT; + for (i = 0; i < len; i++) + if (psinfo->pr_psargs[i] == 0) + psinfo->pr_psargs[i] = ' '; + psinfo->pr_psargs[len] = 0; + + rcu_read_lock(); + psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); + rcu_read_unlock(); + psinfo->pr_pid = task_pid_vnr(p); + psinfo->pr_pgrp = task_pgrp_vnr(p); + psinfo->pr_sid = task_session_vnr(p); + + i = p->state ? ffz(~p->state) + 1 : 0; + psinfo->pr_state = i; + psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; + psinfo->pr_zomb = psinfo->pr_sname == 'Z'; + psinfo->pr_nice = task_nice(p); + psinfo->pr_flag = p->flags; + rcu_read_lock(); + cred = __task_cred(p); + SET_UID(psinfo->pr_uid, cred->uid); + SET_GID(psinfo->pr_gid, cred->gid); + rcu_read_unlock(); + strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); + + return 0; +} + +/* Here is the structure in which status of each thread is captured. */ +struct elf_thread_status +{ + struct list_head list; + struct elf_prstatus prstatus; /* NT_PRSTATUS */ + elf_fpregset_t fpu; /* NT_PRFPREG */ + struct task_struct *thread; +#ifdef ELF_CORE_COPY_XFPREGS + elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ +#endif + struct memelfnote notes[3]; + int num_notes; +}; + +/* + * In order to add the specific thread information for the elf file format, + * we need to keep a linked list of every thread's pr_status and then create + * a single section for them in the final core file. + */ +static int elf_dump_thread_status(long signr, struct elf_thread_status *t) +{ + struct task_struct *p = t->thread; + int sz = 0; + + t->num_notes = 0; + + fill_prstatus(&t->prstatus, p, signr); + elf_core_copy_task_regs(p, &t->prstatus.pr_reg); + + fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), + &t->prstatus); + t->num_notes++; + sz += notesize(&t->notes[0]); + + t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu); + if (t->prstatus.pr_fpvalid) { + fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), + &t->fpu); + t->num_notes++; + sz += notesize(&t->notes[1]); + } + +#ifdef ELF_CORE_COPY_XFPREGS + if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { + fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, + sizeof(t->xfpu), &t->xfpu); + t->num_notes++; + sz += notesize(&t->notes[2]); + } +#endif + return sz; +} + +static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, + elf_addr_t e_shoff, int segs) +{ + elf->e_shoff = e_shoff; + elf->e_shentsize = sizeof(*shdr4extnum); + elf->e_shnum = 1; + elf->e_shstrndx = SHN_UNDEF; + + memset(shdr4extnum, 0, sizeof(*shdr4extnum)); + + shdr4extnum->sh_type = SHT_NULL; + shdr4extnum->sh_size = elf->e_shnum; + shdr4extnum->sh_link = elf->e_shstrndx; + shdr4extnum->sh_info = segs; +} + +/* + * dump the segments for an MMU process + */ +#ifdef CONFIG_MMU +static int elf_fdpic_dump_segments(struct file *file, size_t *size, + unsigned long *limit, unsigned long mm_flags) +{ + struct vm_area_struct *vma; + int err = 0; + + for (vma = current->mm->mmap; vma; vma = vma->vm_next) { + unsigned long addr; + + if (!maydump(vma, mm_flags)) + continue; + + for (addr = vma->vm_start; addr < vma->vm_end; + addr += PAGE_SIZE) { + struct page *page = get_dump_page(addr); + if (page) { + void *kaddr = kmap(page); + *size += PAGE_SIZE; + if (*size > *limit) + err = -EFBIG; + else if (!dump_write(file, kaddr, PAGE_SIZE)) + err = -EIO; + kunmap(page); + page_cache_release(page); + } else if (!dump_seek(file, PAGE_SIZE)) + err = -EFBIG; + if (err) + goto out; + } + } +out: + return err; +} +#endif + +/* + * dump the segments for a NOMMU process + */ +#ifndef CONFIG_MMU +static int elf_fdpic_dump_segments(struct file *file, size_t *size, + unsigned long *limit, unsigned long mm_flags) +{ + struct vm_area_struct *vma; + + for (vma = current->mm->mmap; vma; vma = vma->vm_next) { + if (!maydump(vma, mm_flags)) + continue; + + if ((*size += PAGE_SIZE) > *limit) + return -EFBIG; + + if (!dump_write(file, (void *) vma->vm_start, + vma->vm_end - vma->vm_start)) + return -EIO; + } + + return 0; +} +#endif + +static size_t elf_core_vma_data_size(unsigned long mm_flags) +{ + struct vm_area_struct *vma; + size_t size = 0; + + for (vma = current->mm->mmap; vma; vma = vma->vm_next) + if (maydump(vma, mm_flags)) + size += vma->vm_end - vma->vm_start; + return size; +} + +/* + * Actual dumper + * + * This is a two-pass process; first we find the offsets of the bits, + * and then they are actually written out. If we run out of core limit + * we just truncate. + */ +static int elf_fdpic_core_dump(struct coredump_params *cprm) +{ +#define NUM_NOTES 6 + int has_dumped = 0; + mm_segment_t fs; + int segs; + size_t size = 0; + int i; + struct vm_area_struct *vma; + struct elfhdr *elf = NULL; + loff_t offset = 0, dataoff, foffset; + int numnote; + struct memelfnote *notes = NULL; + struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ + struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ + LIST_HEAD(thread_list); + struct list_head *t; + elf_fpregset_t *fpu = NULL; +#ifdef ELF_CORE_COPY_XFPREGS + elf_fpxregset_t *xfpu = NULL; +#endif + int thread_status_size = 0; + elf_addr_t *auxv; + struct elf_phdr *phdr4note = NULL; + struct elf_shdr *shdr4extnum = NULL; + Elf_Half e_phnum; + elf_addr_t e_shoff; + + /* + * We no longer stop all VM operations. + * + * This is because those proceses that could possibly change map_count + * or the mmap / vma pages are now blocked in do_exit on current + * finishing this core dump. + * + * Only ptrace can touch these memory addresses, but it doesn't change + * the map_count or the pages allocated. So no possibility of crashing + * exists while dumping the mm->vm_next areas to the core file. + */ + + /* alloc memory for large data structures: too large to be on stack */ + elf = kmalloc(sizeof(*elf), GFP_KERNEL); + if (!elf) + goto cleanup; + prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL); + if (!prstatus) + goto cleanup; + psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); + if (!psinfo) + goto cleanup; + notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL); + if (!notes) + goto cleanup; + fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); + if (!fpu) + goto cleanup; +#ifdef ELF_CORE_COPY_XFPREGS + xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); + if (!xfpu) + goto cleanup; +#endif + + if (cprm->signr) { + struct core_thread *ct; + struct elf_thread_status *tmp; + + for (ct = current->mm->core_state->dumper.next; + ct; ct = ct->next) { + tmp = kzalloc(sizeof(*tmp), GFP_KERNEL); + if (!tmp) + goto cleanup; + + tmp->thread = ct->task; + list_add(&tmp->list, &thread_list); + } + + list_for_each(t, &thread_list) { + struct elf_thread_status *tmp; + int sz; + + tmp = list_entry(t, struct elf_thread_status, list); + sz = elf_dump_thread_status(cprm->signr, tmp); + thread_status_size += sz; + } + } + + /* now collect the dump for the current */ + fill_prstatus(prstatus, current, cprm->signr); + elf_core_copy_regs(&prstatus->pr_reg, cprm->regs); + + segs = current->mm->map_count; + segs += elf_core_extra_phdrs(); + + /* for notes section */ + segs++; + + /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid + * this, kernel supports extended numbering. Have a look at + * include/linux/elf.h for further information. */ + e_phnum = segs > PN_XNUM ? PN_XNUM : segs; + + /* Set up header */ + fill_elf_fdpic_header(elf, e_phnum); + + has_dumped = 1; + current->flags |= PF_DUMPCORE; + + /* + * Set up the notes in similar form to SVR4 core dumps made + * with info from their /proc. + */ + + fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); + fill_psinfo(psinfo, current->group_leader, current->mm); + fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); + + numnote = 2; + + auxv = (elf_addr_t *) current->mm->saved_auxv; + + i = 0; + do + i += 2; + while (auxv[i - 2] != AT_NULL); + fill_note(¬es[numnote++], "CORE", NT_AUXV, + i * sizeof(elf_addr_t), auxv); + + /* Try to dump the FPU. */ + if ((prstatus->pr_fpvalid = + elf_core_copy_task_fpregs(current, cprm->regs, fpu))) + fill_note(notes + numnote++, + "CORE", NT_PRFPREG, sizeof(*fpu), fpu); +#ifdef ELF_CORE_COPY_XFPREGS + if (elf_core_copy_task_xfpregs(current, xfpu)) + fill_note(notes + numnote++, + "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu); +#endif + + fs = get_fs(); + set_fs(KERNEL_DS); + + offset += sizeof(*elf); /* Elf header */ + offset += segs * sizeof(struct elf_phdr); /* Program headers */ + foffset = offset; + + /* Write notes phdr entry */ + { + int sz = 0; + + for (i = 0; i < numnote; i++) + sz += notesize(notes + i); + + sz += thread_status_size; + + phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); + if (!phdr4note) + goto end_coredump; + + fill_elf_note_phdr(phdr4note, sz, offset); + offset += sz; + } + + /* Page-align dumped data */ + dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); + + offset += elf_core_vma_data_size(cprm->mm_flags); + offset += elf_core_extra_data_size(); + e_shoff = offset; + + if (e_phnum == PN_XNUM) { + shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); + if (!shdr4extnum) + goto end_coredump; + fill_extnum_info(elf, shdr4extnum, e_shoff, segs); + } + + offset = dataoff; + + size += sizeof(*elf); + if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf))) + goto end_coredump; + + size += sizeof(*phdr4note); + if (size > cprm->limit + || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note))) + goto end_coredump; + + /* write program headers for segments dump */ + for (vma = current->mm->mmap; vma; vma = vma->vm_next) { + struct elf_phdr phdr; + size_t sz; + + sz = vma->vm_end - vma->vm_start; + + phdr.p_type = PT_LOAD; + phdr.p_offset = offset; + phdr.p_vaddr = vma->vm_start; + phdr.p_paddr = 0; + phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0; + phdr.p_memsz = sz; + offset += phdr.p_filesz; + phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; + if (vma->vm_flags & VM_WRITE) + phdr.p_flags |= PF_W; + if (vma->vm_flags & VM_EXEC) + phdr.p_flags |= PF_X; + phdr.p_align = ELF_EXEC_PAGESIZE; + + size += sizeof(phdr); + if (size > cprm->limit + || !dump_write(cprm->file, &phdr, sizeof(phdr))) + goto end_coredump; + } + + if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit)) + goto end_coredump; + + /* write out the notes section */ + for (i = 0; i < numnote; i++) + if (!writenote(notes + i, cprm->file, &foffset)) + goto end_coredump; + + /* write out the thread status notes section */ + list_for_each(t, &thread_list) { + struct elf_thread_status *tmp = + list_entry(t, struct elf_thread_status, list); + + for (i = 0; i < tmp->num_notes; i++) + if (!writenote(&tmp->notes[i], cprm->file, &foffset)) + goto end_coredump; + } + + if (!dump_seek(cprm->file, dataoff - foffset)) + goto end_coredump; + + if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit, + cprm->mm_flags) < 0) + goto end_coredump; + + if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit)) + goto end_coredump; + + if (e_phnum == PN_XNUM) { + size += sizeof(*shdr4extnum); + if (size > cprm->limit + || !dump_write(cprm->file, shdr4extnum, + sizeof(*shdr4extnum))) + goto end_coredump; + } + + if (cprm->file->f_pos != offset) { + /* Sanity check */ + printk(KERN_WARNING + "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", + cprm->file->f_pos, offset); + } + +end_coredump: + set_fs(fs); + +cleanup: + while (!list_empty(&thread_list)) { + struct list_head *tmp = thread_list.next; + list_del(tmp); + kfree(list_entry(tmp, struct elf_thread_status, list)); + } + kfree(phdr4note); + kfree(elf); + kfree(prstatus); + kfree(psinfo); + kfree(notes); + kfree(fpu); + kfree(shdr4extnum); +#ifdef ELF_CORE_COPY_XFPREGS + kfree(xfpu); +#endif + return has_dumped; +#undef NUM_NOTES +} + +#endif /* CONFIG_ELF_CORE */ |