/* 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> 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) { return register_binfmt(&elf_fdpic_format); } 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. */ if (file_permission(interpreter, MAY_READ) < 0) bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; 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; 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; 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; down_write(¤t->mm->mmap_sem); current->mm->start_brk = do_mmap(NULL, 0, stack_size, stack_prot, MAP_PRIVATE | MAP_ANONYMOUS | MAP_UNINITIALIZED | MAP_GROWSDOWN, 0); if (IS_ERR_VALUE(current->mm->start_brk)) { up_write(¤t->mm->mmap_sem); retval = current->mm->start_brk; current->mm->start_brk = 0; goto error_kill; } 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 install_exec_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", 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; 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_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) { ret = clear_user((void *) (seg->addr + phdr->p_filesz), phdr->p_memsz - phdr->p_filesz); if (ret) return ret; } 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, ret; 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_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); ret = clear_user((void __user *) maddr, disp); if (ret) return ret; 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); ret = clear_user((void __user *) maddr + phdr->p_filesz, excess1); if (ret) return ret; } #else if (excess > 0) { kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr + phdr->p_filesz, excess); ret = clear_user((void *) maddr + phdr->p_filesz, excess); if (ret) return ret; } #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); #ifdef ELF_CORE_COPY_XFPREGS kfree(xfpu); #endif return has_dumped; #undef NUM_NOTES } #endif /* CONFIG_ELF_CORE */