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4589ff7ca8
At exec time when we mmap the new executable via MAP_DENYWRITE we have it opened via do_open_execat() and already deny_write_access()'ed the file successfully. Once exec completes, we allow_write_acces(); however, we set mm->exe_file in begin_new_exec() via set_mm_exe_file() and also deny_write_access() as long as mm->exe_file remains set. We'll effectively deny write access to our executable via mm->exe_file until mm->exe_file is changed -- when the process is removed, on new exec, or via sys_prctl(PR_SET_MM_MAP/EXE_FILE). Let's remove all usage of MAP_DENYWRITE, it's no longer necessary for mm->exe_file. In case of an elf interpreter, we'll now only deny write access to the file during exec. This is somewhat okay, because the interpreter behaves (and sometime is) a shared library; all shared libraries, especially the ones loaded directly in user space like via dlopen() won't ever be mapped via MAP_DENYWRITE, because we ignore that from user space completely; these shared libraries can always be modified while mapped and executed. Let's only special-case the main executable, denying write access while being executed by a process. This can be considered a minor user space visible change. While this is a cleanup, it also fixes part of a problem reported with VM_DENYWRITE on overlayfs, as VM_DENYWRITE is effectively unused with this patch and will be removed next: "Overlayfs did not honor positive i_writecount on realfile for VM_DENYWRITE mappings." [1] [1] https://lore.kernel.org/r/YNHXzBgzRrZu1MrD@miu.piliscsaba.redhat.com/ Reported-by: Chengguang Xu <cgxu519@mykernel.net> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: David Hildenbrand <david@redhat.com>
1664 lines
44 KiB
C
1664 lines
44 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* binfmt_elf_fdpic.c: FDPIC ELF binary format
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*
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* Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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* Derived from binfmt_elf.c
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*/
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/stat.h>
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#include <linux/sched.h>
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#include <linux/sched/coredump.h>
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#include <linux/sched/task_stack.h>
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#include <linux/sched/cputime.h>
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#include <linux/mm.h>
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#include <linux/mman.h>
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#include <linux/errno.h>
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#include <linux/signal.h>
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#include <linux/binfmts.h>
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#include <linux/string.h>
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#include <linux/file.h>
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#include <linux/fcntl.h>
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#include <linux/slab.h>
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#include <linux/pagemap.h>
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#include <linux/security.h>
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#include <linux/highmem.h>
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#include <linux/highuid.h>
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#include <linux/personality.h>
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#include <linux/ptrace.h>
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#include <linux/init.h>
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#include <linux/elf.h>
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#include <linux/elf-fdpic.h>
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#include <linux/elfcore.h>
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#include <linux/coredump.h>
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#include <linux/dax.h>
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#include <linux/regset.h>
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#include <linux/uaccess.h>
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#include <asm/param.h>
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typedef char *elf_caddr_t;
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#if 0
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#define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
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#else
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#define kdebug(fmt, ...) do {} while(0)
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#endif
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#if 0
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#define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
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#else
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#define kdcore(fmt, ...) do {} while(0)
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#endif
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MODULE_LICENSE("GPL");
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static int load_elf_fdpic_binary(struct linux_binprm *);
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static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
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static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
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struct mm_struct *, const char *);
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static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
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struct elf_fdpic_params *,
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struct elf_fdpic_params *);
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#ifndef CONFIG_MMU
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static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
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struct file *,
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struct mm_struct *);
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#endif
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static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
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struct file *, struct mm_struct *);
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#ifdef CONFIG_ELF_CORE
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static int elf_fdpic_core_dump(struct coredump_params *cprm);
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#endif
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static struct linux_binfmt elf_fdpic_format = {
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.module = THIS_MODULE,
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.load_binary = load_elf_fdpic_binary,
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#ifdef CONFIG_ELF_CORE
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.core_dump = elf_fdpic_core_dump,
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#endif
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.min_coredump = ELF_EXEC_PAGESIZE,
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};
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static int __init init_elf_fdpic_binfmt(void)
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{
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register_binfmt(&elf_fdpic_format);
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return 0;
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}
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static void __exit exit_elf_fdpic_binfmt(void)
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{
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unregister_binfmt(&elf_fdpic_format);
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}
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core_initcall(init_elf_fdpic_binfmt);
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module_exit(exit_elf_fdpic_binfmt);
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static int is_elf(struct elfhdr *hdr, struct file *file)
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{
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if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
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return 0;
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if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
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return 0;
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if (!elf_check_arch(hdr))
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return 0;
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if (!file->f_op->mmap)
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return 0;
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return 1;
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}
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#ifndef elf_check_fdpic
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#define elf_check_fdpic(x) 0
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#endif
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#ifndef elf_check_const_displacement
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#define elf_check_const_displacement(x) 0
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#endif
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static int is_constdisp(struct elfhdr *hdr)
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{
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if (!elf_check_fdpic(hdr))
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return 1;
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if (elf_check_const_displacement(hdr))
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return 1;
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return 0;
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}
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/*****************************************************************************/
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/*
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* read the program headers table into memory
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*/
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static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
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struct file *file)
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{
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struct elf32_phdr *phdr;
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unsigned long size;
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int retval, loop;
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loff_t pos = params->hdr.e_phoff;
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if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
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return -ENOMEM;
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if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
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return -ENOMEM;
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size = params->hdr.e_phnum * sizeof(struct elf_phdr);
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params->phdrs = kmalloc(size, GFP_KERNEL);
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if (!params->phdrs)
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return -ENOMEM;
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retval = kernel_read(file, params->phdrs, size, &pos);
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if (unlikely(retval != size))
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return retval < 0 ? retval : -ENOEXEC;
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/* determine stack size for this binary */
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phdr = params->phdrs;
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for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
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if (phdr->p_type != PT_GNU_STACK)
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continue;
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if (phdr->p_flags & PF_X)
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params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
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else
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params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
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params->stack_size = phdr->p_memsz;
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break;
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}
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return 0;
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}
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/*****************************************************************************/
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/*
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* load an fdpic binary into various bits of memory
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*/
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static int load_elf_fdpic_binary(struct linux_binprm *bprm)
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{
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struct elf_fdpic_params exec_params, interp_params;
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struct pt_regs *regs = current_pt_regs();
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struct elf_phdr *phdr;
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unsigned long stack_size, entryaddr;
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#ifdef ELF_FDPIC_PLAT_INIT
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unsigned long dynaddr;
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#endif
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#ifndef CONFIG_MMU
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unsigned long stack_prot;
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#endif
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struct file *interpreter = NULL; /* to shut gcc up */
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char *interpreter_name = NULL;
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int executable_stack;
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int retval, i;
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loff_t pos;
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kdebug("____ LOAD %d ____", current->pid);
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memset(&exec_params, 0, sizeof(exec_params));
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memset(&interp_params, 0, sizeof(interp_params));
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exec_params.hdr = *(struct elfhdr *) bprm->buf;
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exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
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/* check that this is a binary we know how to deal with */
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retval = -ENOEXEC;
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if (!is_elf(&exec_params.hdr, bprm->file))
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goto error;
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if (!elf_check_fdpic(&exec_params.hdr)) {
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#ifdef CONFIG_MMU
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/* binfmt_elf handles non-fdpic elf except on nommu */
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goto error;
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#else
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/* nommu can only load ET_DYN (PIE) ELF */
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if (exec_params.hdr.e_type != ET_DYN)
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goto error;
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#endif
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}
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/* read the program header table */
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retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
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if (retval < 0)
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goto error;
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/* scan for a program header that specifies an interpreter */
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phdr = exec_params.phdrs;
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for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
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switch (phdr->p_type) {
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case PT_INTERP:
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retval = -ENOMEM;
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if (phdr->p_filesz > PATH_MAX)
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goto error;
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retval = -ENOENT;
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if (phdr->p_filesz < 2)
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goto error;
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/* read the name of the interpreter into memory */
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interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
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if (!interpreter_name)
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goto error;
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pos = phdr->p_offset;
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retval = kernel_read(bprm->file, interpreter_name,
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phdr->p_filesz, &pos);
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if (unlikely(retval != phdr->p_filesz)) {
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if (retval >= 0)
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retval = -ENOEXEC;
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goto error;
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}
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retval = -ENOENT;
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if (interpreter_name[phdr->p_filesz - 1] != '\0')
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goto error;
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kdebug("Using ELF interpreter %s", interpreter_name);
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/* replace the program with the interpreter */
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interpreter = open_exec(interpreter_name);
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retval = PTR_ERR(interpreter);
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if (IS_ERR(interpreter)) {
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interpreter = NULL;
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goto error;
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}
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/*
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* If the binary is not readable then enforce
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* mm->dumpable = 0 regardless of the interpreter's
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* permissions.
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*/
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would_dump(bprm, interpreter);
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pos = 0;
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retval = kernel_read(interpreter, bprm->buf,
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BINPRM_BUF_SIZE, &pos);
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if (unlikely(retval != BINPRM_BUF_SIZE)) {
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if (retval >= 0)
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retval = -ENOEXEC;
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goto error;
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}
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interp_params.hdr = *((struct elfhdr *) bprm->buf);
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break;
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case PT_LOAD:
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#ifdef CONFIG_MMU
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if (exec_params.load_addr == 0)
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exec_params.load_addr = phdr->p_vaddr;
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#endif
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break;
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}
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}
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if (is_constdisp(&exec_params.hdr))
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exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
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/* perform insanity checks on the interpreter */
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if (interpreter_name) {
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retval = -ELIBBAD;
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if (!is_elf(&interp_params.hdr, interpreter))
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goto error;
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interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
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/* read the interpreter's program header table */
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retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
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if (retval < 0)
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goto error;
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}
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stack_size = exec_params.stack_size;
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if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
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executable_stack = EXSTACK_ENABLE_X;
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else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
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executable_stack = EXSTACK_DISABLE_X;
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else
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executable_stack = EXSTACK_DEFAULT;
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if (stack_size == 0) {
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stack_size = interp_params.stack_size;
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if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
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executable_stack = EXSTACK_ENABLE_X;
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else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
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executable_stack = EXSTACK_DISABLE_X;
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else
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executable_stack = EXSTACK_DEFAULT;
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}
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retval = -ENOEXEC;
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if (stack_size == 0)
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stack_size = 131072UL; /* same as exec.c's default commit */
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if (is_constdisp(&interp_params.hdr))
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interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
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/* flush all traces of the currently running executable */
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retval = begin_new_exec(bprm);
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if (retval)
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goto error;
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/* there's now no turning back... the old userspace image is dead,
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* defunct, deceased, etc.
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*/
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if (elf_check_fdpic(&exec_params.hdr))
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set_personality(PER_LINUX_FDPIC);
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else
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set_personality(PER_LINUX);
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if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
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current->personality |= READ_IMPLIES_EXEC;
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setup_new_exec(bprm);
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set_binfmt(&elf_fdpic_format);
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current->mm->start_code = 0;
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current->mm->end_code = 0;
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current->mm->start_stack = 0;
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current->mm->start_data = 0;
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current->mm->end_data = 0;
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current->mm->context.exec_fdpic_loadmap = 0;
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current->mm->context.interp_fdpic_loadmap = 0;
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#ifdef CONFIG_MMU
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elf_fdpic_arch_lay_out_mm(&exec_params,
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&interp_params,
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¤t->mm->start_stack,
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¤t->mm->start_brk);
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retval = setup_arg_pages(bprm, current->mm->start_stack,
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executable_stack);
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if (retval < 0)
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goto error;
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#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
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retval = arch_setup_additional_pages(bprm, !!interpreter_name);
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if (retval < 0)
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goto error;
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#endif
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#endif
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/* load the executable and interpreter into memory */
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retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
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"executable");
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if (retval < 0)
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goto error;
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if (interpreter_name) {
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retval = elf_fdpic_map_file(&interp_params, interpreter,
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current->mm, "interpreter");
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if (retval < 0) {
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printk(KERN_ERR "Unable to load interpreter\n");
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goto error;
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}
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allow_write_access(interpreter);
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fput(interpreter);
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interpreter = NULL;
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}
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#ifdef CONFIG_MMU
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if (!current->mm->start_brk)
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current->mm->start_brk = current->mm->end_data;
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current->mm->brk = current->mm->start_brk =
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PAGE_ALIGN(current->mm->start_brk);
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#else
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/* create a stack area and zero-size brk area */
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stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
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if (stack_size < PAGE_SIZE * 2)
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stack_size = PAGE_SIZE * 2;
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stack_prot = PROT_READ | PROT_WRITE;
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if (executable_stack == EXSTACK_ENABLE_X ||
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(executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
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stack_prot |= PROT_EXEC;
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current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
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MAP_PRIVATE | MAP_ANONYMOUS |
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MAP_UNINITIALIZED | MAP_GROWSDOWN,
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0);
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|
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if (IS_ERR_VALUE(current->mm->start_brk)) {
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retval = current->mm->start_brk;
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current->mm->start_brk = 0;
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goto error;
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}
|
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current->mm->brk = current->mm->start_brk;
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current->mm->context.end_brk = current->mm->start_brk;
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current->mm->start_stack = current->mm->start_brk + stack_size;
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#endif
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|
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if (create_elf_fdpic_tables(bprm, current->mm,
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&exec_params, &interp_params) < 0)
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goto error;
|
|
|
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kdebug("- start_code %lx", current->mm->start_code);
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kdebug("- end_code %lx", current->mm->end_code);
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kdebug("- start_data %lx", current->mm->start_data);
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|
kdebug("- end_data %lx", current->mm->end_data);
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|
kdebug("- start_brk %lx", current->mm->start_brk);
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kdebug("- brk %lx", current->mm->brk);
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kdebug("- start_stack %lx", current->mm->start_stack);
|
|
|
|
#ifdef ELF_FDPIC_PLAT_INIT
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/*
|
|
* 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;
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ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
|
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dynaddr);
|
|
#endif
|
|
|
|
finalize_exec(bprm);
|
|
/* 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);
|
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|
|
retval = 0;
|
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|
|
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;
|
|
}
|
|
|
|
/*****************************************************************************/
|
|
|
|
#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;
|
|
int loop;
|
|
int nr; /* reset for each csp adjustment */
|
|
unsigned long flags = 0;
|
|
|
|
#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 (transfer_args_to_stack(bprm, &sp) < 0)
|
|
return -EFAULT;
|
|
sp &= ~15;
|
|
#endif
|
|
|
|
/*
|
|
* 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->have_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, v; \
|
|
\
|
|
ent = (void __user *) csp; \
|
|
v._id = (id); \
|
|
v._val = (val); \
|
|
if (copy_to_user(ent + nr, &v, sizeof(v))) \
|
|
return -EFAULT; \
|
|
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->have_execfd) {
|
|
nr = 0;
|
|
csp -= 2 * sizeof(unsigned long);
|
|
NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
|
|
}
|
|
|
|
nr = 0;
|
|
csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
|
|
NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
|
|
#ifdef ELF_HWCAP2
|
|
NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
|
|
#endif
|
|
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);
|
|
if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
|
|
flags |= AT_FLAGS_PRESERVE_ARGV0;
|
|
NEW_AUX_ENT(AT_FLAGS, flags);
|
|
NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
|
|
NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
|
|
NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
|
|
NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
|
|
NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
|
|
NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
|
|
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);
|
|
if (put_user(bprm->argc, (unsigned long __user *) csp))
|
|
return -EFAULT;
|
|
|
|
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--) {
|
|
if (put_user((elf_caddr_t) p, argv++))
|
|
return -EFAULT;
|
|
len = strnlen_user(p, MAX_ARG_STRLEN);
|
|
if (!len || len > MAX_ARG_STRLEN)
|
|
return -EINVAL;
|
|
p += len;
|
|
}
|
|
if (put_user(NULL, argv))
|
|
return -EFAULT;
|
|
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--) {
|
|
if (put_user((elf_caddr_t)(unsigned long) p, envp++))
|
|
return -EFAULT;
|
|
len = strnlen_user(p, MAX_ARG_STRLEN);
|
|
if (!len || len > MAX_ARG_STRLEN)
|
|
return -EINVAL;
|
|
p += len;
|
|
}
|
|
if (put_user(NULL, envp))
|
|
return -EFAULT;
|
|
current->mm->env_end = (unsigned long) p;
|
|
|
|
mm->start_stack = (unsigned long) sp;
|
|
return 0;
|
|
}
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* 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) {
|
|
Elf32_Dyn __user *dyn;
|
|
Elf32_Sword d_tag;
|
|
|
|
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);
|
|
dyn = (Elf32_Dyn __user *)params->dynamic_addr;
|
|
if (get_user(d_tag, &dyn[tmp - 1].d_tag) ||
|
|
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_inode(file)->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;
|
|
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 */
|
|
maddr = vm_mmap(NULL, load_addr, top - base,
|
|
PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 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;
|
|
|
|
seg->addr = maddr + (phdr->p_vaddr - base);
|
|
seg->p_vaddr = phdr->p_vaddr;
|
|
seg->p_memsz = phdr->p_memsz;
|
|
|
|
ret = read_code(file, seg->addr, phdr->p_offset,
|
|
phdr->p_filesz);
|
|
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;
|
|
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
|
|
|
|
struct elf_prstatus_fdpic
|
|
{
|
|
struct elf_prstatus_common common;
|
|
elf_gregset_t pr_reg; /* GP registers */
|
|
/* When using FDPIC, the loadmap addresses need to be communicated
|
|
* to GDB in order for GDB to do the necessary relocations. The
|
|
* fields (below) used to communicate this information are placed
|
|
* immediately after ``pr_reg'', so that the loadmap addresses may
|
|
* be viewed as part of the register set if so desired.
|
|
*/
|
|
unsigned long pr_exec_fdpic_loadmap;
|
|
unsigned long pr_interp_fdpic_loadmap;
|
|
int pr_fpvalid; /* True if math co-processor being used. */
|
|
};
|
|
|
|
/* 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 */
|
|
|
|
static int writenote(struct memelfnote *men, struct coredump_params *cprm)
|
|
{
|
|
struct elf_note en;
|
|
en.n_namesz = strlen(men->name) + 1;
|
|
en.n_descsz = men->datasz;
|
|
en.n_type = men->type;
|
|
|
|
return dump_emit(cprm, &en, sizeof(en)) &&
|
|
dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
|
|
dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
|
|
}
|
|
|
|
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_common *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);
|
|
prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
|
|
prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
|
|
} else {
|
|
u64 utime, stime;
|
|
|
|
task_cputime(p, &utime, &stime);
|
|
prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
|
|
prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
|
|
}
|
|
prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
|
|
prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
|
|
}
|
|
|
|
static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
|
|
struct mm_struct *mm)
|
|
{
|
|
const struct cred *cred;
|
|
unsigned int i, len;
|
|
unsigned int state;
|
|
|
|
/* 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);
|
|
|
|
state = READ_ONCE(p->__state);
|
|
i = state ? ffz(~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, from_kuid_munged(cred->user_ns, cred->uid));
|
|
SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, 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 elf_thread_status *next;
|
|
struct elf_prstatus_fdpic prstatus; /* NT_PRSTATUS */
|
|
elf_fpregset_t fpu; /* NT_PRFPREG */
|
|
struct memelfnote notes[2];
|
|
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 struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz)
|
|
{
|
|
const struct user_regset_view *view = task_user_regset_view(p);
|
|
struct elf_thread_status *t;
|
|
int i, ret;
|
|
|
|
t = kzalloc(sizeof(struct elf_thread_status), GFP_KERNEL);
|
|
if (!t)
|
|
return t;
|
|
|
|
fill_prstatus(&t->prstatus.common, p, signr);
|
|
t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
|
|
t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
|
|
regset_get(p, &view->regsets[0],
|
|
sizeof(t->prstatus.pr_reg), &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]);
|
|
|
|
for (i = 1; i < view->n; ++i) {
|
|
const struct user_regset *regset = &view->regsets[i];
|
|
if (regset->core_note_type != NT_PRFPREG)
|
|
continue;
|
|
if (regset->active && regset->active(p, regset) <= 0)
|
|
continue;
|
|
ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu);
|
|
if (ret >= 0)
|
|
t->prstatus.pr_fpvalid = 1;
|
|
break;
|
|
}
|
|
|
|
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]);
|
|
}
|
|
return t;
|
|
}
|
|
|
|
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
|
|
*/
|
|
static bool elf_fdpic_dump_segments(struct coredump_params *cprm,
|
|
struct core_vma_metadata *vma_meta,
|
|
int vma_count)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < vma_count; i++) {
|
|
struct core_vma_metadata *meta = vma_meta + i;
|
|
|
|
if (!dump_user_range(cprm, meta->start, meta->dump_size))
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
int has_dumped = 0;
|
|
int vma_count, segs;
|
|
int i;
|
|
struct elfhdr *elf = NULL;
|
|
loff_t offset = 0, dataoff;
|
|
struct memelfnote psinfo_note, auxv_note;
|
|
struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
|
|
struct elf_thread_status *thread_list = NULL;
|
|
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;
|
|
struct core_thread *ct;
|
|
struct elf_thread_status *tmp;
|
|
struct core_vma_metadata *vma_meta = NULL;
|
|
size_t vma_data_size;
|
|
|
|
/* alloc memory for large data structures: too large to be on stack */
|
|
elf = kmalloc(sizeof(*elf), GFP_KERNEL);
|
|
if (!elf)
|
|
goto end_coredump;
|
|
psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
|
|
if (!psinfo)
|
|
goto end_coredump;
|
|
|
|
if (dump_vma_snapshot(cprm, &vma_count, &vma_meta, &vma_data_size))
|
|
goto end_coredump;
|
|
|
|
for (ct = current->mm->core_state->dumper.next;
|
|
ct; ct = ct->next) {
|
|
tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
|
|
ct->task, &thread_status_size);
|
|
if (!tmp)
|
|
goto end_coredump;
|
|
|
|
tmp->next = thread_list;
|
|
thread_list = tmp;
|
|
}
|
|
|
|
/* now collect the dump for the current */
|
|
tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
|
|
current, &thread_status_size);
|
|
if (!tmp)
|
|
goto end_coredump;
|
|
tmp->next = thread_list;
|
|
thread_list = tmp;
|
|
|
|
segs = vma_count + 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;
|
|
/*
|
|
* Set up the notes in similar form to SVR4 core dumps made
|
|
* with info from their /proc.
|
|
*/
|
|
|
|
fill_psinfo(psinfo, current->group_leader, current->mm);
|
|
fill_note(&psinfo_note, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
|
|
thread_status_size += notesize(&psinfo_note);
|
|
|
|
auxv = (elf_addr_t *) current->mm->saved_auxv;
|
|
i = 0;
|
|
do
|
|
i += 2;
|
|
while (auxv[i - 2] != AT_NULL);
|
|
fill_note(&auxv_note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
|
|
thread_status_size += notesize(&auxv_note);
|
|
|
|
offset = sizeof(*elf); /* Elf header */
|
|
offset += segs * sizeof(struct elf_phdr); /* Program headers */
|
|
|
|
/* Write notes phdr entry */
|
|
phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
|
|
if (!phdr4note)
|
|
goto end_coredump;
|
|
|
|
fill_elf_note_phdr(phdr4note, thread_status_size, offset);
|
|
offset += thread_status_size;
|
|
|
|
/* Page-align dumped data */
|
|
dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
|
|
|
|
offset += vma_data_size;
|
|
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;
|
|
|
|
if (!dump_emit(cprm, elf, sizeof(*elf)))
|
|
goto end_coredump;
|
|
|
|
if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
|
|
goto end_coredump;
|
|
|
|
/* write program headers for segments dump */
|
|
for (i = 0; i < vma_count; i++) {
|
|
struct core_vma_metadata *meta = vma_meta + i;
|
|
struct elf_phdr phdr;
|
|
size_t sz;
|
|
|
|
sz = meta->end - meta->start;
|
|
|
|
phdr.p_type = PT_LOAD;
|
|
phdr.p_offset = offset;
|
|
phdr.p_vaddr = meta->start;
|
|
phdr.p_paddr = 0;
|
|
phdr.p_filesz = meta->dump_size;
|
|
phdr.p_memsz = sz;
|
|
offset += phdr.p_filesz;
|
|
phdr.p_flags = 0;
|
|
if (meta->flags & VM_READ)
|
|
phdr.p_flags |= PF_R;
|
|
if (meta->flags & VM_WRITE)
|
|
phdr.p_flags |= PF_W;
|
|
if (meta->flags & VM_EXEC)
|
|
phdr.p_flags |= PF_X;
|
|
phdr.p_align = ELF_EXEC_PAGESIZE;
|
|
|
|
if (!dump_emit(cprm, &phdr, sizeof(phdr)))
|
|
goto end_coredump;
|
|
}
|
|
|
|
if (!elf_core_write_extra_phdrs(cprm, offset))
|
|
goto end_coredump;
|
|
|
|
/* write out the notes section */
|
|
if (!writenote(thread_list->notes, cprm))
|
|
goto end_coredump;
|
|
if (!writenote(&psinfo_note, cprm))
|
|
goto end_coredump;
|
|
if (!writenote(&auxv_note, cprm))
|
|
goto end_coredump;
|
|
for (i = 1; i < thread_list->num_notes; i++)
|
|
if (!writenote(thread_list->notes + i, cprm))
|
|
goto end_coredump;
|
|
|
|
/* write out the thread status notes section */
|
|
for (tmp = thread_list->next; tmp; tmp = tmp->next) {
|
|
for (i = 0; i < tmp->num_notes; i++)
|
|
if (!writenote(&tmp->notes[i], cprm))
|
|
goto end_coredump;
|
|
}
|
|
|
|
dump_skip_to(cprm, dataoff);
|
|
|
|
if (!elf_fdpic_dump_segments(cprm, vma_meta, vma_count))
|
|
goto end_coredump;
|
|
|
|
if (!elf_core_write_extra_data(cprm))
|
|
goto end_coredump;
|
|
|
|
if (e_phnum == PN_XNUM) {
|
|
if (!dump_emit(cprm, 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:
|
|
while (thread_list) {
|
|
tmp = thread_list;
|
|
thread_list = thread_list->next;
|
|
kfree(tmp);
|
|
}
|
|
kvfree(vma_meta);
|
|
kfree(phdr4note);
|
|
kfree(elf);
|
|
kfree(psinfo);
|
|
kfree(shdr4extnum);
|
|
return has_dumped;
|
|
}
|
|
|
|
#endif /* CONFIG_ELF_CORE */
|