![Oliver Neukum](/assets/img/avatar_default.png)
Signed-off-by: Oliver Neukum <oliver@neukum.name> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1528 lines
34 KiB
C
1528 lines
34 KiB
C
/*
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* linux/fs/exec.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*/
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/*
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* #!-checking implemented by tytso.
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*/
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/*
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* Demand-loading implemented 01.12.91 - no need to read anything but
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* the header into memory. The inode of the executable is put into
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* "current->executable", and page faults do the actual loading. Clean.
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*
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* Once more I can proudly say that linux stood up to being changed: it
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* was less than 2 hours work to get demand-loading completely implemented.
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*
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* Demand loading changed July 1993 by Eric Youngdale. Use mmap instead,
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* current->executable is only used by the procfs. This allows a dispatch
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* table to check for several different types of binary formats. We keep
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* trying until we recognize the file or we run out of supported binary
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* formats.
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*/
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#include <linux/config.h>
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#include <linux/slab.h>
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#include <linux/file.h>
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#include <linux/mman.h>
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#include <linux/a.out.h>
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#include <linux/stat.h>
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#include <linux/fcntl.h>
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#include <linux/smp_lock.h>
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#include <linux/init.h>
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#include <linux/pagemap.h>
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#include <linux/highmem.h>
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#include <linux/spinlock.h>
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#include <linux/key.h>
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#include <linux/personality.h>
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#include <linux/binfmts.h>
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#include <linux/swap.h>
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#include <linux/utsname.h>
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#include <linux/module.h>
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#include <linux/namei.h>
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#include <linux/proc_fs.h>
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#include <linux/ptrace.h>
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#include <linux/mount.h>
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#include <linux/security.h>
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#include <linux/syscalls.h>
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#include <linux/rmap.h>
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#include <linux/acct.h>
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#include <linux/cn_proc.h>
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#include <asm/uaccess.h>
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#include <asm/mmu_context.h>
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#ifdef CONFIG_KMOD
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#include <linux/kmod.h>
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#endif
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int core_uses_pid;
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char core_pattern[65] = "core";
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int suid_dumpable = 0;
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EXPORT_SYMBOL(suid_dumpable);
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/* The maximal length of core_pattern is also specified in sysctl.c */
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static struct linux_binfmt *formats;
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static DEFINE_RWLOCK(binfmt_lock);
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int register_binfmt(struct linux_binfmt * fmt)
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{
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struct linux_binfmt ** tmp = &formats;
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if (!fmt)
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return -EINVAL;
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if (fmt->next)
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return -EBUSY;
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write_lock(&binfmt_lock);
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while (*tmp) {
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if (fmt == *tmp) {
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write_unlock(&binfmt_lock);
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return -EBUSY;
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}
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tmp = &(*tmp)->next;
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}
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fmt->next = formats;
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formats = fmt;
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write_unlock(&binfmt_lock);
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return 0;
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}
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EXPORT_SYMBOL(register_binfmt);
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int unregister_binfmt(struct linux_binfmt * fmt)
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{
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struct linux_binfmt ** tmp = &formats;
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write_lock(&binfmt_lock);
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while (*tmp) {
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if (fmt == *tmp) {
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*tmp = fmt->next;
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write_unlock(&binfmt_lock);
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return 0;
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}
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tmp = &(*tmp)->next;
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}
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write_unlock(&binfmt_lock);
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return -EINVAL;
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}
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EXPORT_SYMBOL(unregister_binfmt);
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static inline void put_binfmt(struct linux_binfmt * fmt)
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{
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module_put(fmt->module);
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}
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/*
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* Note that a shared library must be both readable and executable due to
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* security reasons.
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*
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* Also note that we take the address to load from from the file itself.
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*/
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asmlinkage long sys_uselib(const char __user * library)
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{
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struct file * file;
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struct nameidata nd;
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int error;
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error = __user_path_lookup_open(library, LOOKUP_FOLLOW, &nd, FMODE_READ|FMODE_EXEC);
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if (error)
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goto out;
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error = -EINVAL;
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if (!S_ISREG(nd.dentry->d_inode->i_mode))
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goto exit;
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error = vfs_permission(&nd, MAY_READ | MAY_EXEC);
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if (error)
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goto exit;
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file = nameidata_to_filp(&nd, O_RDONLY);
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error = PTR_ERR(file);
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if (IS_ERR(file))
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goto out;
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error = -ENOEXEC;
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if(file->f_op) {
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struct linux_binfmt * fmt;
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read_lock(&binfmt_lock);
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for (fmt = formats ; fmt ; fmt = fmt->next) {
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if (!fmt->load_shlib)
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continue;
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if (!try_module_get(fmt->module))
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continue;
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read_unlock(&binfmt_lock);
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error = fmt->load_shlib(file);
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read_lock(&binfmt_lock);
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put_binfmt(fmt);
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if (error != -ENOEXEC)
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break;
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}
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read_unlock(&binfmt_lock);
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}
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fput(file);
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out:
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return error;
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exit:
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release_open_intent(&nd);
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path_release(&nd);
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goto out;
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}
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/*
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* count() counts the number of strings in array ARGV.
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*/
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static int count(char __user * __user * argv, int max)
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{
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int i = 0;
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if (argv != NULL) {
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for (;;) {
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char __user * p;
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if (get_user(p, argv))
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return -EFAULT;
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if (!p)
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break;
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argv++;
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if(++i > max)
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return -E2BIG;
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cond_resched();
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}
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}
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return i;
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}
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/*
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* 'copy_strings()' copies argument/environment strings from user
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* memory to free pages in kernel mem. These are in a format ready
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* to be put directly into the top of new user memory.
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*/
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static int copy_strings(int argc, char __user * __user * argv,
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struct linux_binprm *bprm)
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{
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struct page *kmapped_page = NULL;
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char *kaddr = NULL;
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int ret;
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while (argc-- > 0) {
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char __user *str;
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int len;
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unsigned long pos;
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if (get_user(str, argv+argc) ||
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!(len = strnlen_user(str, bprm->p))) {
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ret = -EFAULT;
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goto out;
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}
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if (bprm->p < len) {
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ret = -E2BIG;
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goto out;
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}
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bprm->p -= len;
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/* XXX: add architecture specific overflow check here. */
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pos = bprm->p;
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while (len > 0) {
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int i, new, err;
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int offset, bytes_to_copy;
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struct page *page;
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offset = pos % PAGE_SIZE;
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i = pos/PAGE_SIZE;
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page = bprm->page[i];
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new = 0;
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if (!page) {
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page = alloc_page(GFP_HIGHUSER);
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bprm->page[i] = page;
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if (!page) {
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ret = -ENOMEM;
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goto out;
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}
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new = 1;
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}
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if (page != kmapped_page) {
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if (kmapped_page)
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kunmap(kmapped_page);
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kmapped_page = page;
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kaddr = kmap(kmapped_page);
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}
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if (new && offset)
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memset(kaddr, 0, offset);
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bytes_to_copy = PAGE_SIZE - offset;
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if (bytes_to_copy > len) {
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bytes_to_copy = len;
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if (new)
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memset(kaddr+offset+len, 0,
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PAGE_SIZE-offset-len);
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}
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err = copy_from_user(kaddr+offset, str, bytes_to_copy);
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if (err) {
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ret = -EFAULT;
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goto out;
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}
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pos += bytes_to_copy;
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str += bytes_to_copy;
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len -= bytes_to_copy;
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}
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}
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ret = 0;
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out:
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if (kmapped_page)
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kunmap(kmapped_page);
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return ret;
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}
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/*
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* Like copy_strings, but get argv and its values from kernel memory.
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*/
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int copy_strings_kernel(int argc,char ** argv, struct linux_binprm *bprm)
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{
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int r;
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mm_segment_t oldfs = get_fs();
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set_fs(KERNEL_DS);
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r = copy_strings(argc, (char __user * __user *)argv, bprm);
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set_fs(oldfs);
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return r;
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}
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EXPORT_SYMBOL(copy_strings_kernel);
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#ifdef CONFIG_MMU
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/*
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* This routine is used to map in a page into an address space: needed by
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* execve() for the initial stack and environment pages.
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*
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* vma->vm_mm->mmap_sem is held for writing.
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*/
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void install_arg_page(struct vm_area_struct *vma,
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struct page *page, unsigned long address)
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{
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struct mm_struct *mm = vma->vm_mm;
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pte_t * pte;
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spinlock_t *ptl;
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if (unlikely(anon_vma_prepare(vma)))
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goto out;
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flush_dcache_page(page);
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pte = get_locked_pte(mm, address, &ptl);
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if (!pte)
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goto out;
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if (!pte_none(*pte)) {
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pte_unmap_unlock(pte, ptl);
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goto out;
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}
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inc_mm_counter(mm, anon_rss);
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lru_cache_add_active(page);
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set_pte_at(mm, address, pte, pte_mkdirty(pte_mkwrite(mk_pte(
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page, vma->vm_page_prot))));
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page_add_new_anon_rmap(page, vma, address);
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pte_unmap_unlock(pte, ptl);
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/* no need for flush_tlb */
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return;
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out:
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__free_page(page);
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force_sig(SIGKILL, current);
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}
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#define EXTRA_STACK_VM_PAGES 20 /* random */
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int setup_arg_pages(struct linux_binprm *bprm,
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unsigned long stack_top,
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int executable_stack)
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{
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unsigned long stack_base;
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struct vm_area_struct *mpnt;
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struct mm_struct *mm = current->mm;
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int i, ret;
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long arg_size;
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#ifdef CONFIG_STACK_GROWSUP
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/* Move the argument and environment strings to the bottom of the
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* stack space.
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*/
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int offset, j;
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char *to, *from;
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/* Start by shifting all the pages down */
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i = 0;
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for (j = 0; j < MAX_ARG_PAGES; j++) {
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struct page *page = bprm->page[j];
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if (!page)
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continue;
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bprm->page[i++] = page;
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}
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/* Now move them within their pages */
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offset = bprm->p % PAGE_SIZE;
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to = kmap(bprm->page[0]);
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for (j = 1; j < i; j++) {
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memmove(to, to + offset, PAGE_SIZE - offset);
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from = kmap(bprm->page[j]);
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memcpy(to + PAGE_SIZE - offset, from, offset);
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kunmap(bprm->page[j - 1]);
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to = from;
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}
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memmove(to, to + offset, PAGE_SIZE - offset);
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kunmap(bprm->page[j - 1]);
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/* Limit stack size to 1GB */
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stack_base = current->signal->rlim[RLIMIT_STACK].rlim_max;
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if (stack_base > (1 << 30))
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stack_base = 1 << 30;
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stack_base = PAGE_ALIGN(stack_top - stack_base);
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/* Adjust bprm->p to point to the end of the strings. */
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bprm->p = stack_base + PAGE_SIZE * i - offset;
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mm->arg_start = stack_base;
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arg_size = i << PAGE_SHIFT;
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/* zero pages that were copied above */
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while (i < MAX_ARG_PAGES)
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bprm->page[i++] = NULL;
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#else
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stack_base = arch_align_stack(stack_top - MAX_ARG_PAGES*PAGE_SIZE);
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stack_base = PAGE_ALIGN(stack_base);
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bprm->p += stack_base;
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mm->arg_start = bprm->p;
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arg_size = stack_top - (PAGE_MASK & (unsigned long) mm->arg_start);
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#endif
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arg_size += EXTRA_STACK_VM_PAGES * PAGE_SIZE;
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|
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if (bprm->loader)
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bprm->loader += stack_base;
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bprm->exec += stack_base;
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|
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mpnt = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
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if (!mpnt)
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return -ENOMEM;
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memset(mpnt, 0, sizeof(*mpnt));
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down_write(&mm->mmap_sem);
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{
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mpnt->vm_mm = mm;
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#ifdef CONFIG_STACK_GROWSUP
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mpnt->vm_start = stack_base;
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mpnt->vm_end = stack_base + arg_size;
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#else
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mpnt->vm_end = stack_top;
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mpnt->vm_start = mpnt->vm_end - arg_size;
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#endif
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/* Adjust stack execute permissions; explicitly enable
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* for EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X
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* and leave alone (arch default) otherwise. */
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if (unlikely(executable_stack == EXSTACK_ENABLE_X))
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mpnt->vm_flags = VM_STACK_FLAGS | VM_EXEC;
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else if (executable_stack == EXSTACK_DISABLE_X)
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mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC;
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else
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mpnt->vm_flags = VM_STACK_FLAGS;
|
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mpnt->vm_flags |= mm->def_flags;
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mpnt->vm_page_prot = protection_map[mpnt->vm_flags & 0x7];
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if ((ret = insert_vm_struct(mm, mpnt))) {
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up_write(&mm->mmap_sem);
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kmem_cache_free(vm_area_cachep, mpnt);
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return ret;
|
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}
|
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mm->stack_vm = mm->total_vm = vma_pages(mpnt);
|
|
}
|
|
|
|
for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
|
|
struct page *page = bprm->page[i];
|
|
if (page) {
|
|
bprm->page[i] = NULL;
|
|
install_arg_page(mpnt, page, stack_base);
|
|
}
|
|
stack_base += PAGE_SIZE;
|
|
}
|
|
up_write(&mm->mmap_sem);
|
|
|
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return 0;
|
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}
|
|
|
|
EXPORT_SYMBOL(setup_arg_pages);
|
|
|
|
#define free_arg_pages(bprm) do { } while (0)
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|
|
|
#else
|
|
|
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static inline void free_arg_pages(struct linux_binprm *bprm)
|
|
{
|
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int i;
|
|
|
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for (i = 0; i < MAX_ARG_PAGES; i++) {
|
|
if (bprm->page[i])
|
|
__free_page(bprm->page[i]);
|
|
bprm->page[i] = NULL;
|
|
}
|
|
}
|
|
|
|
#endif /* CONFIG_MMU */
|
|
|
|
struct file *open_exec(const char *name)
|
|
{
|
|
struct nameidata nd;
|
|
int err;
|
|
struct file *file;
|
|
|
|
err = path_lookup_open(AT_FDCWD, name, LOOKUP_FOLLOW, &nd, FMODE_READ|FMODE_EXEC);
|
|
file = ERR_PTR(err);
|
|
|
|
if (!err) {
|
|
struct inode *inode = nd.dentry->d_inode;
|
|
file = ERR_PTR(-EACCES);
|
|
if (!(nd.mnt->mnt_flags & MNT_NOEXEC) &&
|
|
S_ISREG(inode->i_mode)) {
|
|
int err = vfs_permission(&nd, MAY_EXEC);
|
|
if (!err && !(inode->i_mode & 0111))
|
|
err = -EACCES;
|
|
file = ERR_PTR(err);
|
|
if (!err) {
|
|
file = nameidata_to_filp(&nd, O_RDONLY);
|
|
if (!IS_ERR(file)) {
|
|
err = deny_write_access(file);
|
|
if (err) {
|
|
fput(file);
|
|
file = ERR_PTR(err);
|
|
}
|
|
}
|
|
out:
|
|
return file;
|
|
}
|
|
}
|
|
release_open_intent(&nd);
|
|
path_release(&nd);
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
EXPORT_SYMBOL(open_exec);
|
|
|
|
int kernel_read(struct file *file, unsigned long offset,
|
|
char *addr, unsigned long count)
|
|
{
|
|
mm_segment_t old_fs;
|
|
loff_t pos = offset;
|
|
int result;
|
|
|
|
old_fs = get_fs();
|
|
set_fs(get_ds());
|
|
/* The cast to a user pointer is valid due to the set_fs() */
|
|
result = vfs_read(file, (void __user *)addr, count, &pos);
|
|
set_fs(old_fs);
|
|
return result;
|
|
}
|
|
|
|
EXPORT_SYMBOL(kernel_read);
|
|
|
|
static int exec_mmap(struct mm_struct *mm)
|
|
{
|
|
struct task_struct *tsk;
|
|
struct mm_struct * old_mm, *active_mm;
|
|
|
|
/* Notify parent that we're no longer interested in the old VM */
|
|
tsk = current;
|
|
old_mm = current->mm;
|
|
mm_release(tsk, old_mm);
|
|
|
|
if (old_mm) {
|
|
/*
|
|
* Make sure that if there is a core dump in progress
|
|
* for the old mm, we get out and die instead of going
|
|
* through with the exec. We must hold mmap_sem around
|
|
* checking core_waiters and changing tsk->mm. The
|
|
* core-inducing thread will increment core_waiters for
|
|
* each thread whose ->mm == old_mm.
|
|
*/
|
|
down_read(&old_mm->mmap_sem);
|
|
if (unlikely(old_mm->core_waiters)) {
|
|
up_read(&old_mm->mmap_sem);
|
|
return -EINTR;
|
|
}
|
|
}
|
|
task_lock(tsk);
|
|
active_mm = tsk->active_mm;
|
|
tsk->mm = mm;
|
|
tsk->active_mm = mm;
|
|
activate_mm(active_mm, mm);
|
|
task_unlock(tsk);
|
|
arch_pick_mmap_layout(mm);
|
|
if (old_mm) {
|
|
up_read(&old_mm->mmap_sem);
|
|
if (active_mm != old_mm) BUG();
|
|
mmput(old_mm);
|
|
return 0;
|
|
}
|
|
mmdrop(active_mm);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* This function makes sure the current process has its own signal table,
|
|
* so that flush_signal_handlers can later reset the handlers without
|
|
* disturbing other processes. (Other processes might share the signal
|
|
* table via the CLONE_SIGHAND option to clone().)
|
|
*/
|
|
static int de_thread(struct task_struct *tsk)
|
|
{
|
|
struct signal_struct *sig = tsk->signal;
|
|
struct sighand_struct *newsighand, *oldsighand = tsk->sighand;
|
|
spinlock_t *lock = &oldsighand->siglock;
|
|
struct task_struct *leader = NULL;
|
|
int count;
|
|
|
|
/*
|
|
* If we don't share sighandlers, then we aren't sharing anything
|
|
* and we can just re-use it all.
|
|
*/
|
|
if (atomic_read(&oldsighand->count) <= 1) {
|
|
BUG_ON(atomic_read(&sig->count) != 1);
|
|
exit_itimers(sig);
|
|
return 0;
|
|
}
|
|
|
|
newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
|
|
if (!newsighand)
|
|
return -ENOMEM;
|
|
|
|
if (thread_group_empty(current))
|
|
goto no_thread_group;
|
|
|
|
/*
|
|
* Kill all other threads in the thread group.
|
|
* We must hold tasklist_lock to call zap_other_threads.
|
|
*/
|
|
read_lock(&tasklist_lock);
|
|
spin_lock_irq(lock);
|
|
if (sig->flags & SIGNAL_GROUP_EXIT) {
|
|
/*
|
|
* Another group action in progress, just
|
|
* return so that the signal is processed.
|
|
*/
|
|
spin_unlock_irq(lock);
|
|
read_unlock(&tasklist_lock);
|
|
kmem_cache_free(sighand_cachep, newsighand);
|
|
return -EAGAIN;
|
|
}
|
|
zap_other_threads(current);
|
|
read_unlock(&tasklist_lock);
|
|
|
|
/*
|
|
* Account for the thread group leader hanging around:
|
|
*/
|
|
count = 1;
|
|
if (!thread_group_leader(current)) {
|
|
count = 2;
|
|
/*
|
|
* The SIGALRM timer survives the exec, but needs to point
|
|
* at us as the new group leader now. We have a race with
|
|
* a timer firing now getting the old leader, so we need to
|
|
* synchronize with any firing (by calling del_timer_sync)
|
|
* before we can safely let the old group leader die.
|
|
*/
|
|
sig->real_timer.data = current;
|
|
spin_unlock_irq(lock);
|
|
if (hrtimer_cancel(&sig->real_timer))
|
|
hrtimer_restart(&sig->real_timer);
|
|
spin_lock_irq(lock);
|
|
}
|
|
while (atomic_read(&sig->count) > count) {
|
|
sig->group_exit_task = current;
|
|
sig->notify_count = count;
|
|
__set_current_state(TASK_UNINTERRUPTIBLE);
|
|
spin_unlock_irq(lock);
|
|
schedule();
|
|
spin_lock_irq(lock);
|
|
}
|
|
sig->group_exit_task = NULL;
|
|
sig->notify_count = 0;
|
|
spin_unlock_irq(lock);
|
|
|
|
/*
|
|
* At this point all other threads have exited, all we have to
|
|
* do is to wait for the thread group leader to become inactive,
|
|
* and to assume its PID:
|
|
*/
|
|
if (!thread_group_leader(current)) {
|
|
struct task_struct *parent;
|
|
struct dentry *proc_dentry1, *proc_dentry2;
|
|
unsigned long ptrace;
|
|
|
|
/*
|
|
* Wait for the thread group leader to be a zombie.
|
|
* It should already be zombie at this point, most
|
|
* of the time.
|
|
*/
|
|
leader = current->group_leader;
|
|
while (leader->exit_state != EXIT_ZOMBIE)
|
|
yield();
|
|
|
|
spin_lock(&leader->proc_lock);
|
|
spin_lock(¤t->proc_lock);
|
|
proc_dentry1 = proc_pid_unhash(current);
|
|
proc_dentry2 = proc_pid_unhash(leader);
|
|
write_lock_irq(&tasklist_lock);
|
|
|
|
BUG_ON(leader->tgid != current->tgid);
|
|
BUG_ON(current->pid == current->tgid);
|
|
/*
|
|
* An exec() starts a new thread group with the
|
|
* TGID of the previous thread group. Rehash the
|
|
* two threads with a switched PID, and release
|
|
* the former thread group leader:
|
|
*/
|
|
ptrace = leader->ptrace;
|
|
parent = leader->parent;
|
|
if (unlikely(ptrace) && unlikely(parent == current)) {
|
|
/*
|
|
* Joker was ptracing his own group leader,
|
|
* and now he wants to be his own parent!
|
|
* We can't have that.
|
|
*/
|
|
ptrace = 0;
|
|
}
|
|
|
|
ptrace_unlink(current);
|
|
ptrace_unlink(leader);
|
|
remove_parent(current);
|
|
remove_parent(leader);
|
|
|
|
switch_exec_pids(leader, current);
|
|
|
|
current->parent = current->real_parent = leader->real_parent;
|
|
leader->parent = leader->real_parent = child_reaper;
|
|
current->group_leader = current;
|
|
leader->group_leader = leader;
|
|
|
|
add_parent(current, current->parent);
|
|
add_parent(leader, leader->parent);
|
|
if (ptrace) {
|
|
current->ptrace = ptrace;
|
|
__ptrace_link(current, parent);
|
|
}
|
|
|
|
list_del(¤t->tasks);
|
|
list_add_tail(¤t->tasks, &init_task.tasks);
|
|
current->exit_signal = SIGCHLD;
|
|
|
|
BUG_ON(leader->exit_state != EXIT_ZOMBIE);
|
|
leader->exit_state = EXIT_DEAD;
|
|
|
|
write_unlock_irq(&tasklist_lock);
|
|
spin_unlock(&leader->proc_lock);
|
|
spin_unlock(¤t->proc_lock);
|
|
proc_pid_flush(proc_dentry1);
|
|
proc_pid_flush(proc_dentry2);
|
|
}
|
|
|
|
/*
|
|
* There may be one thread left which is just exiting,
|
|
* but it's safe to stop telling the group to kill themselves.
|
|
*/
|
|
sig->flags = 0;
|
|
|
|
no_thread_group:
|
|
exit_itimers(sig);
|
|
if (leader)
|
|
release_task(leader);
|
|
|
|
BUG_ON(atomic_read(&sig->count) != 1);
|
|
|
|
if (atomic_read(&oldsighand->count) == 1) {
|
|
/*
|
|
* Now that we nuked the rest of the thread group,
|
|
* it turns out we are not sharing sighand any more either.
|
|
* So we can just keep it.
|
|
*/
|
|
kmem_cache_free(sighand_cachep, newsighand);
|
|
} else {
|
|
/*
|
|
* Move our state over to newsighand and switch it in.
|
|
*/
|
|
spin_lock_init(&newsighand->siglock);
|
|
atomic_set(&newsighand->count, 1);
|
|
memcpy(newsighand->action, oldsighand->action,
|
|
sizeof(newsighand->action));
|
|
|
|
write_lock_irq(&tasklist_lock);
|
|
spin_lock(&oldsighand->siglock);
|
|
spin_lock(&newsighand->siglock);
|
|
|
|
rcu_assign_pointer(current->sighand, newsighand);
|
|
recalc_sigpending();
|
|
|
|
spin_unlock(&newsighand->siglock);
|
|
spin_unlock(&oldsighand->siglock);
|
|
write_unlock_irq(&tasklist_lock);
|
|
|
|
if (atomic_dec_and_test(&oldsighand->count))
|
|
sighand_free(oldsighand);
|
|
}
|
|
|
|
BUG_ON(!thread_group_leader(current));
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* These functions flushes out all traces of the currently running executable
|
|
* so that a new one can be started
|
|
*/
|
|
|
|
static void flush_old_files(struct files_struct * files)
|
|
{
|
|
long j = -1;
|
|
struct fdtable *fdt;
|
|
|
|
spin_lock(&files->file_lock);
|
|
for (;;) {
|
|
unsigned long set, i;
|
|
|
|
j++;
|
|
i = j * __NFDBITS;
|
|
fdt = files_fdtable(files);
|
|
if (i >= fdt->max_fds || i >= fdt->max_fdset)
|
|
break;
|
|
set = fdt->close_on_exec->fds_bits[j];
|
|
if (!set)
|
|
continue;
|
|
fdt->close_on_exec->fds_bits[j] = 0;
|
|
spin_unlock(&files->file_lock);
|
|
for ( ; set ; i++,set >>= 1) {
|
|
if (set & 1) {
|
|
sys_close(i);
|
|
}
|
|
}
|
|
spin_lock(&files->file_lock);
|
|
|
|
}
|
|
spin_unlock(&files->file_lock);
|
|
}
|
|
|
|
void get_task_comm(char *buf, struct task_struct *tsk)
|
|
{
|
|
/* buf must be at least sizeof(tsk->comm) in size */
|
|
task_lock(tsk);
|
|
strncpy(buf, tsk->comm, sizeof(tsk->comm));
|
|
task_unlock(tsk);
|
|
}
|
|
|
|
void set_task_comm(struct task_struct *tsk, char *buf)
|
|
{
|
|
task_lock(tsk);
|
|
strlcpy(tsk->comm, buf, sizeof(tsk->comm));
|
|
task_unlock(tsk);
|
|
}
|
|
|
|
int flush_old_exec(struct linux_binprm * bprm)
|
|
{
|
|
char * name;
|
|
int i, ch, retval;
|
|
struct files_struct *files;
|
|
char tcomm[sizeof(current->comm)];
|
|
|
|
/*
|
|
* Make sure we have a private signal table and that
|
|
* we are unassociated from the previous thread group.
|
|
*/
|
|
retval = de_thread(current);
|
|
if (retval)
|
|
goto out;
|
|
|
|
/*
|
|
* Make sure we have private file handles. Ask the
|
|
* fork helper to do the work for us and the exit
|
|
* helper to do the cleanup of the old one.
|
|
*/
|
|
files = current->files; /* refcounted so safe to hold */
|
|
retval = unshare_files();
|
|
if (retval)
|
|
goto out;
|
|
/*
|
|
* Release all of the old mmap stuff
|
|
*/
|
|
retval = exec_mmap(bprm->mm);
|
|
if (retval)
|
|
goto mmap_failed;
|
|
|
|
bprm->mm = NULL; /* We're using it now */
|
|
|
|
/* This is the point of no return */
|
|
steal_locks(files);
|
|
put_files_struct(files);
|
|
|
|
current->sas_ss_sp = current->sas_ss_size = 0;
|
|
|
|
if (current->euid == current->uid && current->egid == current->gid)
|
|
current->mm->dumpable = 1;
|
|
else
|
|
current->mm->dumpable = suid_dumpable;
|
|
|
|
name = bprm->filename;
|
|
|
|
/* Copies the binary name from after last slash */
|
|
for (i=0; (ch = *(name++)) != '\0';) {
|
|
if (ch == '/')
|
|
i = 0; /* overwrite what we wrote */
|
|
else
|
|
if (i < (sizeof(tcomm) - 1))
|
|
tcomm[i++] = ch;
|
|
}
|
|
tcomm[i] = '\0';
|
|
set_task_comm(current, tcomm);
|
|
|
|
current->flags &= ~PF_RANDOMIZE;
|
|
flush_thread();
|
|
|
|
/* Set the new mm task size. We have to do that late because it may
|
|
* depend on TIF_32BIT which is only updated in flush_thread() on
|
|
* some architectures like powerpc
|
|
*/
|
|
current->mm->task_size = TASK_SIZE;
|
|
|
|
if (bprm->e_uid != current->euid || bprm->e_gid != current->egid ||
|
|
file_permission(bprm->file, MAY_READ) ||
|
|
(bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) {
|
|
suid_keys(current);
|
|
current->mm->dumpable = suid_dumpable;
|
|
}
|
|
|
|
/* An exec changes our domain. We are no longer part of the thread
|
|
group */
|
|
|
|
current->self_exec_id++;
|
|
|
|
flush_signal_handlers(current, 0);
|
|
flush_old_files(current->files);
|
|
|
|
return 0;
|
|
|
|
mmap_failed:
|
|
put_files_struct(current->files);
|
|
current->files = files;
|
|
out:
|
|
return retval;
|
|
}
|
|
|
|
EXPORT_SYMBOL(flush_old_exec);
|
|
|
|
/*
|
|
* Fill the binprm structure from the inode.
|
|
* Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes
|
|
*/
|
|
int prepare_binprm(struct linux_binprm *bprm)
|
|
{
|
|
int mode;
|
|
struct inode * inode = bprm->file->f_dentry->d_inode;
|
|
int retval;
|
|
|
|
mode = inode->i_mode;
|
|
/*
|
|
* Check execute perms again - if the caller has CAP_DAC_OVERRIDE,
|
|
* generic_permission lets a non-executable through
|
|
*/
|
|
if (!(mode & 0111)) /* with at least _one_ execute bit set */
|
|
return -EACCES;
|
|
if (bprm->file->f_op == NULL)
|
|
return -EACCES;
|
|
|
|
bprm->e_uid = current->euid;
|
|
bprm->e_gid = current->egid;
|
|
|
|
if(!(bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)) {
|
|
/* Set-uid? */
|
|
if (mode & S_ISUID) {
|
|
current->personality &= ~PER_CLEAR_ON_SETID;
|
|
bprm->e_uid = inode->i_uid;
|
|
}
|
|
|
|
/* Set-gid? */
|
|
/*
|
|
* If setgid is set but no group execute bit then this
|
|
* is a candidate for mandatory locking, not a setgid
|
|
* executable.
|
|
*/
|
|
if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
|
|
current->personality &= ~PER_CLEAR_ON_SETID;
|
|
bprm->e_gid = inode->i_gid;
|
|
}
|
|
}
|
|
|
|
/* fill in binprm security blob */
|
|
retval = security_bprm_set(bprm);
|
|
if (retval)
|
|
return retval;
|
|
|
|
memset(bprm->buf,0,BINPRM_BUF_SIZE);
|
|
return kernel_read(bprm->file,0,bprm->buf,BINPRM_BUF_SIZE);
|
|
}
|
|
|
|
EXPORT_SYMBOL(prepare_binprm);
|
|
|
|
static int unsafe_exec(struct task_struct *p)
|
|
{
|
|
int unsafe = 0;
|
|
if (p->ptrace & PT_PTRACED) {
|
|
if (p->ptrace & PT_PTRACE_CAP)
|
|
unsafe |= LSM_UNSAFE_PTRACE_CAP;
|
|
else
|
|
unsafe |= LSM_UNSAFE_PTRACE;
|
|
}
|
|
if (atomic_read(&p->fs->count) > 1 ||
|
|
atomic_read(&p->files->count) > 1 ||
|
|
atomic_read(&p->sighand->count) > 1)
|
|
unsafe |= LSM_UNSAFE_SHARE;
|
|
|
|
return unsafe;
|
|
}
|
|
|
|
void compute_creds(struct linux_binprm *bprm)
|
|
{
|
|
int unsafe;
|
|
|
|
if (bprm->e_uid != current->uid)
|
|
suid_keys(current);
|
|
exec_keys(current);
|
|
|
|
task_lock(current);
|
|
unsafe = unsafe_exec(current);
|
|
security_bprm_apply_creds(bprm, unsafe);
|
|
task_unlock(current);
|
|
security_bprm_post_apply_creds(bprm);
|
|
}
|
|
|
|
EXPORT_SYMBOL(compute_creds);
|
|
|
|
void remove_arg_zero(struct linux_binprm *bprm)
|
|
{
|
|
if (bprm->argc) {
|
|
unsigned long offset;
|
|
char * kaddr;
|
|
struct page *page;
|
|
|
|
offset = bprm->p % PAGE_SIZE;
|
|
goto inside;
|
|
|
|
while (bprm->p++, *(kaddr+offset++)) {
|
|
if (offset != PAGE_SIZE)
|
|
continue;
|
|
offset = 0;
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
inside:
|
|
page = bprm->page[bprm->p/PAGE_SIZE];
|
|
kaddr = kmap_atomic(page, KM_USER0);
|
|
}
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
bprm->argc--;
|
|
}
|
|
}
|
|
|
|
EXPORT_SYMBOL(remove_arg_zero);
|
|
|
|
/*
|
|
* cycle the list of binary formats handler, until one recognizes the image
|
|
*/
|
|
int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
|
|
{
|
|
int try,retval;
|
|
struct linux_binfmt *fmt;
|
|
#ifdef __alpha__
|
|
/* handle /sbin/loader.. */
|
|
{
|
|
struct exec * eh = (struct exec *) bprm->buf;
|
|
|
|
if (!bprm->loader && eh->fh.f_magic == 0x183 &&
|
|
(eh->fh.f_flags & 0x3000) == 0x3000)
|
|
{
|
|
struct file * file;
|
|
unsigned long loader;
|
|
|
|
allow_write_access(bprm->file);
|
|
fput(bprm->file);
|
|
bprm->file = NULL;
|
|
|
|
loader = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *);
|
|
|
|
file = open_exec("/sbin/loader");
|
|
retval = PTR_ERR(file);
|
|
if (IS_ERR(file))
|
|
return retval;
|
|
|
|
/* Remember if the application is TASO. */
|
|
bprm->sh_bang = eh->ah.entry < 0x100000000UL;
|
|
|
|
bprm->file = file;
|
|
bprm->loader = loader;
|
|
retval = prepare_binprm(bprm);
|
|
if (retval<0)
|
|
return retval;
|
|
/* should call search_binary_handler recursively here,
|
|
but it does not matter */
|
|
}
|
|
}
|
|
#endif
|
|
retval = security_bprm_check(bprm);
|
|
if (retval)
|
|
return retval;
|
|
|
|
/* kernel module loader fixup */
|
|
/* so we don't try to load run modprobe in kernel space. */
|
|
set_fs(USER_DS);
|
|
retval = -ENOENT;
|
|
for (try=0; try<2; try++) {
|
|
read_lock(&binfmt_lock);
|
|
for (fmt = formats ; fmt ; fmt = fmt->next) {
|
|
int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary;
|
|
if (!fn)
|
|
continue;
|
|
if (!try_module_get(fmt->module))
|
|
continue;
|
|
read_unlock(&binfmt_lock);
|
|
retval = fn(bprm, regs);
|
|
if (retval >= 0) {
|
|
put_binfmt(fmt);
|
|
allow_write_access(bprm->file);
|
|
if (bprm->file)
|
|
fput(bprm->file);
|
|
bprm->file = NULL;
|
|
current->did_exec = 1;
|
|
proc_exec_connector(current);
|
|
return retval;
|
|
}
|
|
read_lock(&binfmt_lock);
|
|
put_binfmt(fmt);
|
|
if (retval != -ENOEXEC || bprm->mm == NULL)
|
|
break;
|
|
if (!bprm->file) {
|
|
read_unlock(&binfmt_lock);
|
|
return retval;
|
|
}
|
|
}
|
|
read_unlock(&binfmt_lock);
|
|
if (retval != -ENOEXEC || bprm->mm == NULL) {
|
|
break;
|
|
#ifdef CONFIG_KMOD
|
|
}else{
|
|
#define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e))
|
|
if (printable(bprm->buf[0]) &&
|
|
printable(bprm->buf[1]) &&
|
|
printable(bprm->buf[2]) &&
|
|
printable(bprm->buf[3]))
|
|
break; /* -ENOEXEC */
|
|
request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2]));
|
|
#endif
|
|
}
|
|
}
|
|
return retval;
|
|
}
|
|
|
|
EXPORT_SYMBOL(search_binary_handler);
|
|
|
|
/*
|
|
* sys_execve() executes a new program.
|
|
*/
|
|
int do_execve(char * filename,
|
|
char __user *__user *argv,
|
|
char __user *__user *envp,
|
|
struct pt_regs * regs)
|
|
{
|
|
struct linux_binprm *bprm;
|
|
struct file *file;
|
|
int retval;
|
|
int i;
|
|
|
|
retval = -ENOMEM;
|
|
bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
|
|
if (!bprm)
|
|
goto out_ret;
|
|
|
|
file = open_exec(filename);
|
|
retval = PTR_ERR(file);
|
|
if (IS_ERR(file))
|
|
goto out_kfree;
|
|
|
|
sched_exec();
|
|
|
|
bprm->p = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *);
|
|
|
|
bprm->file = file;
|
|
bprm->filename = filename;
|
|
bprm->interp = filename;
|
|
bprm->mm = mm_alloc();
|
|
retval = -ENOMEM;
|
|
if (!bprm->mm)
|
|
goto out_file;
|
|
|
|
retval = init_new_context(current, bprm->mm);
|
|
if (retval < 0)
|
|
goto out_mm;
|
|
|
|
bprm->argc = count(argv, bprm->p / sizeof(void *));
|
|
if ((retval = bprm->argc) < 0)
|
|
goto out_mm;
|
|
|
|
bprm->envc = count(envp, bprm->p / sizeof(void *));
|
|
if ((retval = bprm->envc) < 0)
|
|
goto out_mm;
|
|
|
|
retval = security_bprm_alloc(bprm);
|
|
if (retval)
|
|
goto out;
|
|
|
|
retval = prepare_binprm(bprm);
|
|
if (retval < 0)
|
|
goto out;
|
|
|
|
retval = copy_strings_kernel(1, &bprm->filename, bprm);
|
|
if (retval < 0)
|
|
goto out;
|
|
|
|
bprm->exec = bprm->p;
|
|
retval = copy_strings(bprm->envc, envp, bprm);
|
|
if (retval < 0)
|
|
goto out;
|
|
|
|
retval = copy_strings(bprm->argc, argv, bprm);
|
|
if (retval < 0)
|
|
goto out;
|
|
|
|
retval = search_binary_handler(bprm,regs);
|
|
if (retval >= 0) {
|
|
free_arg_pages(bprm);
|
|
|
|
/* execve success */
|
|
security_bprm_free(bprm);
|
|
acct_update_integrals(current);
|
|
kfree(bprm);
|
|
return retval;
|
|
}
|
|
|
|
out:
|
|
/* Something went wrong, return the inode and free the argument pages*/
|
|
for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
|
|
struct page * page = bprm->page[i];
|
|
if (page)
|
|
__free_page(page);
|
|
}
|
|
|
|
if (bprm->security)
|
|
security_bprm_free(bprm);
|
|
|
|
out_mm:
|
|
if (bprm->mm)
|
|
mmdrop(bprm->mm);
|
|
|
|
out_file:
|
|
if (bprm->file) {
|
|
allow_write_access(bprm->file);
|
|
fput(bprm->file);
|
|
}
|
|
|
|
out_kfree:
|
|
kfree(bprm);
|
|
|
|
out_ret:
|
|
return retval;
|
|
}
|
|
|
|
int set_binfmt(struct linux_binfmt *new)
|
|
{
|
|
struct linux_binfmt *old = current->binfmt;
|
|
|
|
if (new) {
|
|
if (!try_module_get(new->module))
|
|
return -1;
|
|
}
|
|
current->binfmt = new;
|
|
if (old)
|
|
module_put(old->module);
|
|
return 0;
|
|
}
|
|
|
|
EXPORT_SYMBOL(set_binfmt);
|
|
|
|
#define CORENAME_MAX_SIZE 64
|
|
|
|
/* format_corename will inspect the pattern parameter, and output a
|
|
* name into corename, which must have space for at least
|
|
* CORENAME_MAX_SIZE bytes plus one byte for the zero terminator.
|
|
*/
|
|
static void format_corename(char *corename, const char *pattern, long signr)
|
|
{
|
|
const char *pat_ptr = pattern;
|
|
char *out_ptr = corename;
|
|
char *const out_end = corename + CORENAME_MAX_SIZE;
|
|
int rc;
|
|
int pid_in_pattern = 0;
|
|
|
|
/* Repeat as long as we have more pattern to process and more output
|
|
space */
|
|
while (*pat_ptr) {
|
|
if (*pat_ptr != '%') {
|
|
if (out_ptr == out_end)
|
|
goto out;
|
|
*out_ptr++ = *pat_ptr++;
|
|
} else {
|
|
switch (*++pat_ptr) {
|
|
case 0:
|
|
goto out;
|
|
/* Double percent, output one percent */
|
|
case '%':
|
|
if (out_ptr == out_end)
|
|
goto out;
|
|
*out_ptr++ = '%';
|
|
break;
|
|
/* pid */
|
|
case 'p':
|
|
pid_in_pattern = 1;
|
|
rc = snprintf(out_ptr, out_end - out_ptr,
|
|
"%d", current->tgid);
|
|
if (rc > out_end - out_ptr)
|
|
goto out;
|
|
out_ptr += rc;
|
|
break;
|
|
/* uid */
|
|
case 'u':
|
|
rc = snprintf(out_ptr, out_end - out_ptr,
|
|
"%d", current->uid);
|
|
if (rc > out_end - out_ptr)
|
|
goto out;
|
|
out_ptr += rc;
|
|
break;
|
|
/* gid */
|
|
case 'g':
|
|
rc = snprintf(out_ptr, out_end - out_ptr,
|
|
"%d", current->gid);
|
|
if (rc > out_end - out_ptr)
|
|
goto out;
|
|
out_ptr += rc;
|
|
break;
|
|
/* signal that caused the coredump */
|
|
case 's':
|
|
rc = snprintf(out_ptr, out_end - out_ptr,
|
|
"%ld", signr);
|
|
if (rc > out_end - out_ptr)
|
|
goto out;
|
|
out_ptr += rc;
|
|
break;
|
|
/* UNIX time of coredump */
|
|
case 't': {
|
|
struct timeval tv;
|
|
do_gettimeofday(&tv);
|
|
rc = snprintf(out_ptr, out_end - out_ptr,
|
|
"%lu", tv.tv_sec);
|
|
if (rc > out_end - out_ptr)
|
|
goto out;
|
|
out_ptr += rc;
|
|
break;
|
|
}
|
|
/* hostname */
|
|
case 'h':
|
|
down_read(&uts_sem);
|
|
rc = snprintf(out_ptr, out_end - out_ptr,
|
|
"%s", system_utsname.nodename);
|
|
up_read(&uts_sem);
|
|
if (rc > out_end - out_ptr)
|
|
goto out;
|
|
out_ptr += rc;
|
|
break;
|
|
/* executable */
|
|
case 'e':
|
|
rc = snprintf(out_ptr, out_end - out_ptr,
|
|
"%s", current->comm);
|
|
if (rc > out_end - out_ptr)
|
|
goto out;
|
|
out_ptr += rc;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
++pat_ptr;
|
|
}
|
|
}
|
|
/* Backward compatibility with core_uses_pid:
|
|
*
|
|
* If core_pattern does not include a %p (as is the default)
|
|
* and core_uses_pid is set, then .%pid will be appended to
|
|
* the filename */
|
|
if (!pid_in_pattern
|
|
&& (core_uses_pid || atomic_read(¤t->mm->mm_users) != 1)) {
|
|
rc = snprintf(out_ptr, out_end - out_ptr,
|
|
".%d", current->tgid);
|
|
if (rc > out_end - out_ptr)
|
|
goto out;
|
|
out_ptr += rc;
|
|
}
|
|
out:
|
|
*out_ptr = 0;
|
|
}
|
|
|
|
static void zap_threads (struct mm_struct *mm)
|
|
{
|
|
struct task_struct *g, *p;
|
|
struct task_struct *tsk = current;
|
|
struct completion *vfork_done = tsk->vfork_done;
|
|
int traced = 0;
|
|
|
|
/*
|
|
* Make sure nobody is waiting for us to release the VM,
|
|
* otherwise we can deadlock when we wait on each other
|
|
*/
|
|
if (vfork_done) {
|
|
tsk->vfork_done = NULL;
|
|
complete(vfork_done);
|
|
}
|
|
|
|
read_lock(&tasklist_lock);
|
|
do_each_thread(g,p)
|
|
if (mm == p->mm && p != tsk) {
|
|
force_sig_specific(SIGKILL, p);
|
|
mm->core_waiters++;
|
|
if (unlikely(p->ptrace) &&
|
|
unlikely(p->parent->mm == mm))
|
|
traced = 1;
|
|
}
|
|
while_each_thread(g,p);
|
|
|
|
read_unlock(&tasklist_lock);
|
|
|
|
if (unlikely(traced)) {
|
|
/*
|
|
* We are zapping a thread and the thread it ptraces.
|
|
* If the tracee went into a ptrace stop for exit tracing,
|
|
* we could deadlock since the tracer is waiting for this
|
|
* coredump to finish. Detach them so they can both die.
|
|
*/
|
|
write_lock_irq(&tasklist_lock);
|
|
do_each_thread(g,p) {
|
|
if (mm == p->mm && p != tsk &&
|
|
p->ptrace && p->parent->mm == mm) {
|
|
__ptrace_detach(p, 0);
|
|
}
|
|
} while_each_thread(g,p);
|
|
write_unlock_irq(&tasklist_lock);
|
|
}
|
|
}
|
|
|
|
static void coredump_wait(struct mm_struct *mm)
|
|
{
|
|
DECLARE_COMPLETION(startup_done);
|
|
int core_waiters;
|
|
|
|
mm->core_startup_done = &startup_done;
|
|
|
|
zap_threads(mm);
|
|
core_waiters = mm->core_waiters;
|
|
up_write(&mm->mmap_sem);
|
|
|
|
if (core_waiters)
|
|
wait_for_completion(&startup_done);
|
|
BUG_ON(mm->core_waiters);
|
|
}
|
|
|
|
int do_coredump(long signr, int exit_code, struct pt_regs * regs)
|
|
{
|
|
char corename[CORENAME_MAX_SIZE + 1];
|
|
struct mm_struct *mm = current->mm;
|
|
struct linux_binfmt * binfmt;
|
|
struct inode * inode;
|
|
struct file * file;
|
|
int retval = 0;
|
|
int fsuid = current->fsuid;
|
|
int flag = 0;
|
|
|
|
binfmt = current->binfmt;
|
|
if (!binfmt || !binfmt->core_dump)
|
|
goto fail;
|
|
down_write(&mm->mmap_sem);
|
|
if (!mm->dumpable) {
|
|
up_write(&mm->mmap_sem);
|
|
goto fail;
|
|
}
|
|
|
|
/*
|
|
* We cannot trust fsuid as being the "true" uid of the
|
|
* process nor do we know its entire history. We only know it
|
|
* was tainted so we dump it as root in mode 2.
|
|
*/
|
|
if (mm->dumpable == 2) { /* Setuid core dump mode */
|
|
flag = O_EXCL; /* Stop rewrite attacks */
|
|
current->fsuid = 0; /* Dump root private */
|
|
}
|
|
mm->dumpable = 0;
|
|
|
|
retval = -EAGAIN;
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
|
|
current->signal->flags = SIGNAL_GROUP_EXIT;
|
|
current->signal->group_exit_code = exit_code;
|
|
current->signal->group_stop_count = 0;
|
|
retval = 0;
|
|
}
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
if (retval) {
|
|
up_write(&mm->mmap_sem);
|
|
goto fail;
|
|
}
|
|
|
|
init_completion(&mm->core_done);
|
|
coredump_wait(mm);
|
|
|
|
/*
|
|
* Clear any false indication of pending signals that might
|
|
* be seen by the filesystem code called to write the core file.
|
|
*/
|
|
clear_thread_flag(TIF_SIGPENDING);
|
|
|
|
if (current->signal->rlim[RLIMIT_CORE].rlim_cur < binfmt->min_coredump)
|
|
goto fail_unlock;
|
|
|
|
/*
|
|
* lock_kernel() because format_corename() is controlled by sysctl, which
|
|
* uses lock_kernel()
|
|
*/
|
|
lock_kernel();
|
|
format_corename(corename, core_pattern, signr);
|
|
unlock_kernel();
|
|
file = filp_open(corename, O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag, 0600);
|
|
if (IS_ERR(file))
|
|
goto fail_unlock;
|
|
inode = file->f_dentry->d_inode;
|
|
if (inode->i_nlink > 1)
|
|
goto close_fail; /* multiple links - don't dump */
|
|
if (d_unhashed(file->f_dentry))
|
|
goto close_fail;
|
|
|
|
if (!S_ISREG(inode->i_mode))
|
|
goto close_fail;
|
|
if (!file->f_op)
|
|
goto close_fail;
|
|
if (!file->f_op->write)
|
|
goto close_fail;
|
|
if (do_truncate(file->f_dentry, 0, 0, file) != 0)
|
|
goto close_fail;
|
|
|
|
retval = binfmt->core_dump(signr, regs, file);
|
|
|
|
if (retval)
|
|
current->signal->group_exit_code |= 0x80;
|
|
close_fail:
|
|
filp_close(file, NULL);
|
|
fail_unlock:
|
|
current->fsuid = fsuid;
|
|
complete_all(&mm->core_done);
|
|
fail:
|
|
return retval;
|
|
}
|