coredump: move core dump functionality into its own file

This prepares for making core dump functionality optional. The variable "suid_dumpable" and associated functions are left in fs/exec.c because they're used elsewhere, such as in ptrace. Signed-off-by: Alex Kelly <alex.page.kelly@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

coredump: move core dump functionality into its own file
This prepares for making core dump functionality optional. The variable "suid_dumpable" and associated functions are left in fs/exec.c because they're used elsewhere, such as in ptrace. Signed-off-by: Alex Kelly <alex.page.kelly@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Alex Kelly · Al Viro
1 parent f34f9d186d
Showing 4 changed files with 689 additions and 645 deletions Side-by-side Diff
fs/Makefile
fs/coredump.c
fs/exec.c
include/linux/sched.h
@@ -11,7 +11,7 @@
 		attr.o bad_inode.o file.o filesystems.o namespace.o \
 		seq_file.o xattr.o libfs.o fs-writeback.o \
 		pnode.o drop_caches.o splice.o sync.o utimes.o \
-		stack.o fs_struct.o statfs.o
+		stack.o fs_struct.o statfs.o coredump.o
  
 ifeq ($(CONFIG_BLOCK),y)
 obj-y +=	buffer.o bio.o block_dev.o direct-io.o mpage.o ioprio.o
+#include <linux/slab.h>
+#include <linux/file.h>
+#include <linux/fdtable.h>
+#include <linux/mm.h>
+#include <linux/stat.h>
+#include <linux/fcntl.h>
+#include <linux/swap.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/pagemap.h>
+#include <linux/perf_event.h>
+#include <linux/highmem.h>
+#include <linux/spinlock.h>
+#include <linux/key.h>
+#include <linux/personality.h>
+#include <linux/binfmts.h>
+#include <linux/utsname.h>
+#include <linux/pid_namespace.h>
+#include <linux/module.h>
+#include <linux/namei.h>
+#include <linux/mount.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/tsacct_kern.h>
+#include <linux/cn_proc.h>
+#include <linux/audit.h>
+#include <linux/tracehook.h>
+#include <linux/kmod.h>
+#include <linux/fsnotify.h>
+#include <linux/fs_struct.h>
+#include <linux/pipe_fs_i.h>
+#include <linux/oom.h>
+#include <linux/compat.h>
+
+#include <asm/uaccess.h>
+#include <asm/mmu_context.h>
+#include <asm/tlb.h>
+#include <asm/exec.h>
+
+#include <trace/events/task.h>
+#include "internal.h"
+
+#include <trace/events/sched.h>
+
+int core_uses_pid;
+char core_pattern[CORENAME_MAX_SIZE] = "core";
+unsigned int core_pipe_limit;
+
+struct core_name {
+	char *corename;
+	int used, size;
+};
+static atomic_t call_count = ATOMIC_INIT(1);
+
+/* The maximal length of core_pattern is also specified in sysctl.c */
+
+static int expand_corename(struct core_name *cn)
+{
+	char *old_corename = cn->corename;
+
+	cn->size = CORENAME_MAX_SIZE * atomic_inc_return(&call_count);
+	cn->corename = krealloc(old_corename, cn->size, GFP_KERNEL);
+
+	if (!cn->corename) {
+		kfree(old_corename);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int cn_printf(struct core_name *cn, const char *fmt, ...)
+{
+	char *cur;
+	int need;
+	int ret;
+	va_list arg;
+
+	va_start(arg, fmt);
+	need = vsnprintf(NULL, 0, fmt, arg);
+	va_end(arg);
+
+	if (likely(need < cn->size - cn->used - 1))
+		goto out_printf;
+
+	ret = expand_corename(cn);
+	if (ret)
+		goto expand_fail;
+
+out_printf:
+	cur = cn->corename + cn->used;
+	va_start(arg, fmt);
+	vsnprintf(cur, need + 1, fmt, arg);
+	va_end(arg);
+	cn->used += need;
+	return 0;
+
+expand_fail:
+	return ret;
+}
+
+static void cn_escape(char *str)
+{
+	for (; *str; str++)
+		if (*str == '/')
+			*str = '!';
+}
+
+static int cn_print_exe_file(struct core_name *cn)
+{
+	struct file *exe_file;
+	char *pathbuf, *path;
+	int ret;
+
+	exe_file = get_mm_exe_file(current->mm);
+	if (!exe_file) {
+		char *commstart = cn->corename + cn->used;
+		ret = cn_printf(cn, "%s (path unknown)", current->comm);
+		cn_escape(commstart);
+		return ret;
+	}
+
+	pathbuf = kmalloc(PATH_MAX, GFP_TEMPORARY);
+	if (!pathbuf) {
+		ret = -ENOMEM;
+		goto put_exe_file;
+	}
+
+	path = d_path(&exe_file->f_path, pathbuf, PATH_MAX);
+	if (IS_ERR(path)) {
+		ret = PTR_ERR(path);
+		goto free_buf;
+	}
+
+	cn_escape(path);
+
+	ret = cn_printf(cn, "%s", path);
+
+free_buf:
+	kfree(pathbuf);
+put_exe_file:
+	fput(exe_file);
+	return ret;
+}
+
+/* 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 int format_corename(struct core_name *cn, long signr)
+{
+	const struct cred *cred = current_cred();
+	const char *pat_ptr = core_pattern;
+	int ispipe = (*pat_ptr == '|');
+	int pid_in_pattern = 0;
+	int err = 0;
+
+	cn->size = CORENAME_MAX_SIZE * atomic_read(&call_count);
+	cn->corename = kmalloc(cn->size, GFP_KERNEL);
+	cn->used = 0;
+
+	if (!cn->corename)
+		return -ENOMEM;
+
+	/* Repeat as long as we have more pattern to process and more output
+	   space */
+	while (*pat_ptr) {
+		if (*pat_ptr != '%') {
+			if (*pat_ptr == 0)
+				goto out;
+			err = cn_printf(cn, "%c", *pat_ptr++);
+		} else {
+			switch (*++pat_ptr) {
+			/* single % at the end, drop that */
+			case 0:
+				goto out;
+			/* Double percent, output one percent */
+			case '%':
+				err = cn_printf(cn, "%c", '%');
+				break;
+			/* pid */
+			case 'p':
+				pid_in_pattern = 1;
+				err = cn_printf(cn, "%d",
+					      task_tgid_vnr(current));
+				break;
+			/* uid */
+			case 'u':
+				err = cn_printf(cn, "%d", cred->uid);
+				break;
+			/* gid */
+			case 'g':
+				err = cn_printf(cn, "%d", cred->gid);
+				break;
+			/* signal that caused the coredump */
+			case 's':
+				err = cn_printf(cn, "%ld", signr);
+				break;
+			/* UNIX time of coredump */
+			case 't': {
+				struct timeval tv;
+				do_gettimeofday(&tv);
+				err = cn_printf(cn, "%lu", tv.tv_sec);
+				break;
+			}
+			/* hostname */
+			case 'h': {
+				char *namestart = cn->corename + cn->used;
+				down_read(&uts_sem);
+				err = cn_printf(cn, "%s",
+					      utsname()->nodename);
+				up_read(&uts_sem);
+				cn_escape(namestart);
+				break;
+			}
+			/* executable */
+			case 'e': {
+				char *commstart = cn->corename + cn->used;
+				err = cn_printf(cn, "%s", current->comm);
+				cn_escape(commstart);
+				break;
+			}
+			case 'E':
+				err = cn_print_exe_file(cn);
+				break;
+			/* core limit size */
+			case 'c':
+				err = cn_printf(cn, "%lu",
+					      rlimit(RLIMIT_CORE));
+				break;
+			default:
+				break;
+			}
+			++pat_ptr;
+		}
+
+		if (err)
+			return err;
+	}
+
+	/* 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. Do not do this for piped commands. */
+	if (!ispipe && !pid_in_pattern && core_uses_pid) {
+		err = cn_printf(cn, ".%d", task_tgid_vnr(current));
+		if (err)
+			return err;
+	}
+out:
+	return ispipe;
+}
+
+static int zap_process(struct task_struct *start, int exit_code)
+{
+	struct task_struct *t;
+	int nr = 0;
+
+	start->signal->flags = SIGNAL_GROUP_EXIT;
+	start->signal->group_exit_code = exit_code;
+	start->signal->group_stop_count = 0;
+
+	t = start;
+	do {
+		task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK);
+		if (t != current && t->mm) {
+			sigaddset(&t->pending.signal, SIGKILL);
+			signal_wake_up(t, 1);
+			nr++;
+		}
+	} while_each_thread(start, t);
+
+	return nr;
+}
+
+static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm,
+				struct core_state *core_state, int exit_code)
+{
+	struct task_struct *g, *p;
+	unsigned long flags;
+	int nr = -EAGAIN;
+
+	spin_lock_irq(&tsk->sighand->siglock);
+	if (!signal_group_exit(tsk->signal)) {
+		mm->core_state = core_state;
+		nr = zap_process(tsk, exit_code);
+	}
+	spin_unlock_irq(&tsk->sighand->siglock);
+	if (unlikely(nr < 0))
+		return nr;
+
+	if (atomic_read(&mm->mm_users) == nr + 1)
+		goto done;
+	/*
+	 * We should find and kill all tasks which use this mm, and we should
+	 * count them correctly into ->nr_threads. We don't take tasklist
+	 * lock, but this is safe wrt:
+	 *
+	 * fork:
+	 *	None of sub-threads can fork after zap_process(leader). All
+	 *	processes which were created before this point should be
+	 *	visible to zap_threads() because copy_process() adds the new
+	 *	process to the tail of init_task.tasks list, and lock/unlock
+	 *	of ->siglock provides a memory barrier.
+	 *
+	 * do_exit:
+	 *	The caller holds mm->mmap_sem. This means that the task which
+	 *	uses this mm can't pass exit_mm(), so it can't exit or clear
+	 *	its ->mm.
+	 *
+	 * de_thread:
+	 *	It does list_replace_rcu(&leader->tasks, &current->tasks),
+	 *	we must see either old or new leader, this does not matter.
+	 *	However, it can change p->sighand, so lock_task_sighand(p)
+	 *	must be used. Since p->mm != NULL and we hold ->mmap_sem
+	 *	it can't fail.
+	 *
+	 *	Note also that "g" can be the old leader with ->mm == NULL
+	 *	and already unhashed and thus removed from ->thread_group.
+	 *	This is OK, __unhash_process()->list_del_rcu() does not
+	 *	clear the ->next pointer, we will find the new leader via
+	 *	next_thread().
+	 */
+	rcu_read_lock();
+	for_each_process(g) {
+		if (g == tsk->group_leader)
+			continue;
+		if (g->flags & PF_KTHREAD)
+			continue;
+		p = g;
+		do {
+			if (p->mm) {
+				if (unlikely(p->mm == mm)) {
+					lock_task_sighand(p, &flags);
+					nr += zap_process(p, exit_code);
+					unlock_task_sighand(p, &flags);
+				}
+				break;
+			}
+		} while_each_thread(g, p);
+	}
+	rcu_read_unlock();
+done:
+	atomic_set(&core_state->nr_threads, nr);
+	return nr;
+}
+
+static int coredump_wait(int exit_code, struct core_state *core_state)
+{
+	struct task_struct *tsk = current;
+	struct mm_struct *mm = tsk->mm;
+	int core_waiters = -EBUSY;
+
+	init_completion(&core_state->startup);
+	core_state->dumper.task = tsk;
+	core_state->dumper.next = NULL;
+
+	down_write(&mm->mmap_sem);
+	if (!mm->core_state)
+		core_waiters = zap_threads(tsk, mm, core_state, exit_code);
+	up_write(&mm->mmap_sem);
+
+	if (core_waiters > 0) {
+		struct core_thread *ptr;
+
+		wait_for_completion(&core_state->startup);
+		/*
+		 * Wait for all the threads to become inactive, so that
+		 * all the thread context (extended register state, like
+		 * fpu etc) gets copied to the memory.
+		 */
+		ptr = core_state->dumper.next;
+		while (ptr != NULL) {
+			wait_task_inactive(ptr->task, 0);
+			ptr = ptr->next;
+		}
+	}
+
+	return core_waiters;
+}
+
+static void coredump_finish(struct mm_struct *mm)
+{
+	struct core_thread *curr, *next;
+	struct task_struct *task;
+
+	next = mm->core_state->dumper.next;
+	while ((curr = next) != NULL) {
+		next = curr->next;
+		task = curr->task;
+		/*
+		 * see exit_mm(), curr->task must not see
+		 * ->task == NULL before we read ->next.
+		 */
+		smp_mb();
+		curr->task = NULL;
+		wake_up_process(task);
+	}
+
+	mm->core_state = NULL;
+}
+
+static void wait_for_dump_helpers(struct file *file)
+{
+	struct pipe_inode_info *pipe;
+
+	pipe = file->f_path.dentry->d_inode->i_pipe;
+
+	pipe_lock(pipe);
+	pipe->readers++;
+	pipe->writers--;
+
+	while ((pipe->readers > 1) && (!signal_pending(current))) {
+		wake_up_interruptible_sync(&pipe->wait);
+		kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
+		pipe_wait(pipe);
+	}
+
+	pipe->readers--;
+	pipe->writers++;
+	pipe_unlock(pipe);
+
+}
+
+/*
+ * umh_pipe_setup
+ * helper function to customize the process used
+ * to collect the core in userspace.  Specifically
+ * it sets up a pipe and installs it as fd 0 (stdin)
+ * for the process.  Returns 0 on success, or
+ * PTR_ERR on failure.
+ * Note that it also sets the core limit to 1.  This
+ * is a special value that we use to trap recursive
+ * core dumps
+ */
+static int umh_pipe_setup(struct subprocess_info *info, struct cred *new)
+{
+	struct file *files[2];
+	struct coredump_params *cp = (struct coredump_params *)info->data;
+	int err = create_pipe_files(files, 0);
+	if (err)
+		return err;
+
+	cp->file = files[1];
+
+	replace_fd(0, files[0], 0);
+	/* and disallow core files too */
+	current->signal->rlim[RLIMIT_CORE] = (struct rlimit){1, 1};
+
+	return 0;
+}
+
+void do_coredump(long signr, int exit_code, struct pt_regs *regs)
+{
+	struct core_state core_state;
+	struct core_name cn;
+	struct mm_struct *mm = current->mm;
+	struct linux_binfmt * binfmt;
+	const struct cred *old_cred;
+	struct cred *cred;
+	int retval = 0;
+	int flag = 0;
+	int ispipe;
+	struct files_struct *displaced;
+	bool need_nonrelative = false;
+	static atomic_t core_dump_count = ATOMIC_INIT(0);
+	struct coredump_params cprm = {
+		.signr = signr,
+		.regs = regs,
+		.limit = rlimit(RLIMIT_CORE),
+		/*
+		 * We must use the same mm->flags while dumping core to avoid
+		 * inconsistency of bit flags, since this flag is not protected
+		 * by any locks.
+		 */
+		.mm_flags = mm->flags,
+	};
+
+	audit_core_dumps(signr);
+
+	binfmt = mm->binfmt;
+	if (!binfmt || !binfmt->core_dump)
+		goto fail;
+	if (!__get_dumpable(cprm.mm_flags))
+		goto fail;
+
+	cred = prepare_creds();
+	if (!cred)
+		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, and only into a controlled
+	 * environment (pipe handler or fully qualified path).
+	 */
+	if (__get_dumpable(cprm.mm_flags) == SUID_DUMPABLE_SAFE) {
+		/* Setuid core dump mode */
+		flag = O_EXCL;		/* Stop rewrite attacks */
+		cred->fsuid = GLOBAL_ROOT_UID;	/* Dump root private */
+		need_nonrelative = true;
+	}
+
+	retval = coredump_wait(exit_code, &core_state);
+	if (retval < 0)
+		goto fail_creds;
+
+	old_cred = override_creds(cred);
+
+	/*
+	 * 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);
+
+	ispipe = format_corename(&cn, signr);
+
+ 	if (ispipe) {
+		int dump_count;
+		char **helper_argv;
+
+		if (ispipe < 0) {
+			printk(KERN_WARNING "format_corename failed\n");
+			printk(KERN_WARNING "Aborting core\n");
+			goto fail_corename;
+		}
+
+		if (cprm.limit == 1) {
+			/* See umh_pipe_setup() which sets RLIMIT_CORE = 1.
+			 *
+			 * Normally core limits are irrelevant to pipes, since
+			 * we're not writing to the file system, but we use
+			 * cprm.limit of 1 here as a speacial value, this is a
+			 * consistent way to catch recursive crashes.
+			 * We can still crash if the core_pattern binary sets
+			 * RLIM_CORE = !1, but it runs as root, and can do
+			 * lots of stupid things.
+			 *
+			 * Note that we use task_tgid_vnr here to grab the pid
+			 * of the process group leader.  That way we get the
+			 * right pid if a thread in a multi-threaded
+			 * core_pattern process dies.
+			 */
+			printk(KERN_WARNING
+				"Process %d(%s) has RLIMIT_CORE set to 1\n",
+				task_tgid_vnr(current), current->comm);
+			printk(KERN_WARNING "Aborting core\n");
+			goto fail_unlock;
+		}
+		cprm.limit = RLIM_INFINITY;
+
+		dump_count = atomic_inc_return(&core_dump_count);
+		if (core_pipe_limit && (core_pipe_limit < dump_count)) {
+			printk(KERN_WARNING "Pid %d(%s) over core_pipe_limit\n",
+			       task_tgid_vnr(current), current->comm);
+			printk(KERN_WARNING "Skipping core dump\n");
+			goto fail_dropcount;
+		}
+
+		helper_argv = argv_split(GFP_KERNEL, cn.corename+1, NULL);
+		if (!helper_argv) {
+			printk(KERN_WARNING "%s failed to allocate memory\n",
+			       __func__);
+			goto fail_dropcount;
+		}
+
+		retval = call_usermodehelper_fns(helper_argv[0], helper_argv,
+					NULL, UMH_WAIT_EXEC, umh_pipe_setup,
+					NULL, &cprm);
+		argv_free(helper_argv);
+		if (retval) {
+ 			printk(KERN_INFO "Core dump to %s pipe failed\n",
+			       cn.corename);
+			goto close_fail;
+ 		}
+	} else {
+		struct inode *inode;
+
+		if (cprm.limit < binfmt->min_coredump)
+			goto fail_unlock;
+
+		if (need_nonrelative && cn.corename[0] != '/') {
+			printk(KERN_WARNING "Pid %d(%s) can only dump core "\
+				"to fully qualified path!\n",
+				task_tgid_vnr(current), current->comm);
+			printk(KERN_WARNING "Skipping core dump\n");
+			goto fail_unlock;
+		}
+
+		cprm.file = filp_open(cn.corename,
+				 O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag,
+				 0600);
+		if (IS_ERR(cprm.file))
+			goto fail_unlock;
+
+		inode = cprm.file->f_path.dentry->d_inode;
+		if (inode->i_nlink > 1)
+			goto close_fail;
+		if (d_unhashed(cprm.file->f_path.dentry))
+			goto close_fail;
+		/*
+		 * AK: actually i see no reason to not allow this for named
+		 * pipes etc, but keep the previous behaviour for now.
+		 */
+		if (!S_ISREG(inode->i_mode))
+			goto close_fail;
+		/*
+		 * Dont allow local users get cute and trick others to coredump
+		 * into their pre-created files.
+		 */
+		if (!uid_eq(inode->i_uid, current_fsuid()))
+			goto close_fail;
+		if (!cprm.file->f_op || !cprm.file->f_op->write)
+			goto close_fail;
+		if (do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file))
+			goto close_fail;
+	}
+
+	/* get us an unshared descriptor table; almost always a no-op */
+	retval = unshare_files(&displaced);
+	if (retval)
+		goto close_fail;
+	if (displaced)
+		put_files_struct(displaced);
+	retval = binfmt->core_dump(&cprm);
+	if (retval)
+		current->signal->group_exit_code |= 0x80;
+
+	if (ispipe && core_pipe_limit)
+		wait_for_dump_helpers(cprm.file);
+close_fail:
+	if (cprm.file)
+		filp_close(cprm.file, NULL);
+fail_dropcount:
+	if (ispipe)
+		atomic_dec(&core_dump_count);
+fail_unlock:
+	kfree(cn.corename);
+fail_corename:
+	coredump_finish(mm);
+	revert_creds(old_cred);
+fail_creds:
+	put_cred(cred);
+fail:
+	return;
+}
+
+/*
+ * Core dumping helper functions.  These are the only things you should
+ * do on a core-file: use only these functions to write out all the
+ * necessary info.
+ */
+int dump_write(struct file *file, const void *addr, int nr)
+{
+	return access_ok(VERIFY_READ, addr, nr) && file->f_op->write(file, addr, nr, &file->f_pos) == nr;
+}
+EXPORT_SYMBOL(dump_write);
+
+int dump_seek(struct file *file, loff_t off)
+{
+	int ret = 1;
+
+	if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
+		if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
+			return 0;
+	} else {
+		char *buf = (char *)get_zeroed_page(GFP_KERNEL);
+
+		if (!buf)
+			return 0;
+		while (off > 0) {
+			unsigned long n = off;
+
+			if (n > PAGE_SIZE)
+				n = PAGE_SIZE;
+			if (!dump_write(file, buf, n)) {
+				ret = 0;
+				break;
+			}
+			off -= n;
+		}
+		free_page((unsigned long)buf);
+	}
+	return ret;
+}
+EXPORT_SYMBOL(dump_seek);
@@ -66,19 +66,8 @@
  
 #include <trace/events/sched.h>
  
-int core_uses_pid;
-char core_pattern[CORENAME_MAX_SIZE] = "core";
-unsigned int core_pipe_limit;
 int suid_dumpable = 0;
  
-struct core_name {
-	char *corename;
-	int used, size;
-};
-static atomic_t call_count = ATOMIC_INIT(1);
-
-/* The maximal length of core_pattern is also specified in sysctl.c */
-
 static LIST_HEAD(formats);
 static DEFINE_RWLOCK(binfmt_lock);
  
@@ -1603,353 +1592,6 @@
  
 EXPORT_SYMBOL(set_binfmt);
  
-static int expand_corename(struct core_name *cn)
-{
-	char *old_corename = cn->corename;
-
-	cn->size = CORENAME_MAX_SIZE * atomic_inc_return(&call_count);
-	cn->corename = krealloc(old_corename, cn->size, GFP_KERNEL);
-
-	if (!cn->corename) {
-		kfree(old_corename);
-		return -ENOMEM;
-	}
-
-	return 0;
-}
-
-static int cn_printf(struct core_name *cn, const char *fmt, ...)
-{
-	char *cur;
-	int need;
-	int ret;
-	va_list arg;
-
-	va_start(arg, fmt);
-	need = vsnprintf(NULL, 0, fmt, arg);
-	va_end(arg);
-
-	if (likely(need < cn->size - cn->used - 1))
-		goto out_printf;
-
-	ret = expand_corename(cn);
-	if (ret)
-		goto expand_fail;
-
-out_printf:
-	cur = cn->corename + cn->used;
-	va_start(arg, fmt);
-	vsnprintf(cur, need + 1, fmt, arg);
-	va_end(arg);
-	cn->used += need;
-	return 0;
-
-expand_fail:
-	return ret;
-}
-
-static void cn_escape(char *str)
-{
-	for (; *str; str++)
-		if (*str == '/')
-			*str = '!';
-}
-
-static int cn_print_exe_file(struct core_name *cn)
-{
-	struct file *exe_file;
-	char *pathbuf, *path;
-	int ret;
-
-	exe_file = get_mm_exe_file(current->mm);
-	if (!exe_file) {
-		char *commstart = cn->corename + cn->used;
-		ret = cn_printf(cn, "%s (path unknown)", current->comm);
-		cn_escape(commstart);
-		return ret;
-	}
-
-	pathbuf = kmalloc(PATH_MAX, GFP_TEMPORARY);
-	if (!pathbuf) {
-		ret = -ENOMEM;
-		goto put_exe_file;
-	}
-
-	path = d_path(&exe_file->f_path, pathbuf, PATH_MAX);
-	if (IS_ERR(path)) {
-		ret = PTR_ERR(path);
-		goto free_buf;
-	}
-
-	cn_escape(path);
-
-	ret = cn_printf(cn, "%s", path);
-
-free_buf:
-	kfree(pathbuf);
-put_exe_file:
-	fput(exe_file);
-	return ret;
-}
-
-/* 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 int format_corename(struct core_name *cn, long signr)
-{
-	const struct cred *cred = current_cred();
-	const char *pat_ptr = core_pattern;
-	int ispipe = (*pat_ptr == '|');
-	int pid_in_pattern = 0;
-	int err = 0;
-
-	cn->size = CORENAME_MAX_SIZE * atomic_read(&call_count);
-	cn->corename = kmalloc(cn->size, GFP_KERNEL);
-	cn->used = 0;
-
-	if (!cn->corename)
-		return -ENOMEM;
-
-	/* Repeat as long as we have more pattern to process and more output
-	   space */
-	while (*pat_ptr) {
-		if (*pat_ptr != '%') {
-			if (*pat_ptr == 0)
-				goto out;
-			err = cn_printf(cn, "%c", *pat_ptr++);
-		} else {
-			switch (*++pat_ptr) {
-			/* single % at the end, drop that */
-			case 0:
-				goto out;
-			/* Double percent, output one percent */
-			case '%':
-				err = cn_printf(cn, "%c", '%');
-				break;
-			/* pid */
-			case 'p':
-				pid_in_pattern = 1;
-				err = cn_printf(cn, "%d",
-					      task_tgid_vnr(current));
-				break;
-			/* uid */
-			case 'u':
-				err = cn_printf(cn, "%d", cred->uid);
-				break;
-			/* gid */
-			case 'g':
-				err = cn_printf(cn, "%d", cred->gid);
-				break;
-			/* signal that caused the coredump */
-			case 's':
-				err = cn_printf(cn, "%ld", signr);
-				break;
-			/* UNIX time of coredump */
-			case 't': {
-				struct timeval tv;
-				do_gettimeofday(&tv);
-				err = cn_printf(cn, "%lu", tv.tv_sec);
-				break;
-			}
-			/* hostname */
-			case 'h': {
-				char *namestart = cn->corename + cn->used;
-				down_read(&uts_sem);
-				err = cn_printf(cn, "%s",
-					      utsname()->nodename);
-				up_read(&uts_sem);
-				cn_escape(namestart);
-				break;
-			}
-			/* executable */
-			case 'e': {
-				char *commstart = cn->corename + cn->used;
-				err = cn_printf(cn, "%s", current->comm);
-				cn_escape(commstart);
-				break;
-			}
-			case 'E':
-				err = cn_print_exe_file(cn);
-				break;
-			/* core limit size */
-			case 'c':
-				err = cn_printf(cn, "%lu",
-					      rlimit(RLIMIT_CORE));
-				break;
-			default:
-				break;
-			}
-			++pat_ptr;
-		}
-
-		if (err)
-			return err;
-	}
-
-	/* 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. Do not do this for piped commands. */
-	if (!ispipe && !pid_in_pattern && core_uses_pid) {
-		err = cn_printf(cn, ".%d", task_tgid_vnr(current));
-		if (err)
-			return err;
-	}
-out:
-	return ispipe;
-}
-
-static int zap_process(struct task_struct *start, int exit_code)
-{
-	struct task_struct *t;
-	int nr = 0;
-
-	start->signal->flags = SIGNAL_GROUP_EXIT;
-	start->signal->group_exit_code = exit_code;
-	start->signal->group_stop_count = 0;
-
-	t = start;
-	do {
-		task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK);
-		if (t != current && t->mm) {
-			sigaddset(&t->pending.signal, SIGKILL);
-			signal_wake_up(t, 1);
-			nr++;
-		}
-	} while_each_thread(start, t);
-
-	return nr;
-}
-
-static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm,
-				struct core_state *core_state, int exit_code)
-{
-	struct task_struct *g, *p;
-	unsigned long flags;
-	int nr = -EAGAIN;
-
-	spin_lock_irq(&tsk->sighand->siglock);
-	if (!signal_group_exit(tsk->signal)) {
-		mm->core_state = core_state;
-		nr = zap_process(tsk, exit_code);
-	}
-	spin_unlock_irq(&tsk->sighand->siglock);
-	if (unlikely(nr < 0))
-		return nr;
-
-	if (atomic_read(&mm->mm_users) == nr + 1)
-		goto done;
-	/*
-	 * We should find and kill all tasks which use this mm, and we should
-	 * count them correctly into ->nr_threads. We don't take tasklist
-	 * lock, but this is safe wrt:
-	 *
-	 * fork:
-	 *	None of sub-threads can fork after zap_process(leader). All
-	 *	processes which were created before this point should be
-	 *	visible to zap_threads() because copy_process() adds the new
-	 *	process to the tail of init_task.tasks list, and lock/unlock
-	 *	of ->siglock provides a memory barrier.
-	 *
-	 * do_exit:
-	 *	The caller holds mm->mmap_sem. This means that the task which
-	 *	uses this mm can't pass exit_mm(), so it can't exit or clear
-	 *	its ->mm.
-	 *
-	 * de_thread:
-	 *	It does list_replace_rcu(&leader->tasks, &current->tasks),
-	 *	we must see either old or new leader, this does not matter.
-	 *	However, it can change p->sighand, so lock_task_sighand(p)
-	 *	must be used. Since p->mm != NULL and we hold ->mmap_sem
-	 *	it can't fail.
-	 *
-	 *	Note also that "g" can be the old leader with ->mm == NULL
-	 *	and already unhashed and thus removed from ->thread_group.
-	 *	This is OK, __unhash_process()->list_del_rcu() does not
-	 *	clear the ->next pointer, we will find the new leader via
-	 *	next_thread().
-	 */
-	rcu_read_lock();
-	for_each_process(g) {
-		if (g == tsk->group_leader)
-			continue;
-		if (g->flags & PF_KTHREAD)
-			continue;
-		p = g;
-		do {
-			if (p->mm) {
-				if (unlikely(p->mm == mm)) {
-					lock_task_sighand(p, &flags);
-					nr += zap_process(p, exit_code);
-					unlock_task_sighand(p, &flags);
-				}
-				break;
-			}
-		} while_each_thread(g, p);
-	}
-	rcu_read_unlock();
-done:
-	atomic_set(&core_state->nr_threads, nr);
-	return nr;
-}
-
-static int coredump_wait(int exit_code, struct core_state *core_state)
-{
-	struct task_struct *tsk = current;
-	struct mm_struct *mm = tsk->mm;
-	int core_waiters = -EBUSY;
-
-	init_completion(&core_state->startup);
-	core_state->dumper.task = tsk;
-	core_state->dumper.next = NULL;
-
-	down_write(&mm->mmap_sem);
-	if (!mm->core_state)
-		core_waiters = zap_threads(tsk, mm, core_state, exit_code);
-	up_write(&mm->mmap_sem);
-
-	if (core_waiters > 0) {
-		struct core_thread *ptr;
-
-		wait_for_completion(&core_state->startup);
-		/*
-		 * Wait for all the threads to become inactive, so that
-		 * all the thread context (extended register state, like
-		 * fpu etc) gets copied to the memory.
-		 */
-		ptr = core_state->dumper.next;
-		while (ptr != NULL) {
-			wait_task_inactive(ptr->task, 0);
-			ptr = ptr->next;
-		}
-	}
-
-	return core_waiters;
-}
-
-static void coredump_finish(struct mm_struct *mm)
-{
-	struct core_thread *curr, *next;
-	struct task_struct *task;
-
-	next = mm->core_state->dumper.next;
-	while ((curr = next) != NULL) {
-		next = curr->next;
-		task = curr->task;
-		/*
-		 * see exit_mm(), curr->task must not see
-		 * ->task == NULL before we read ->next.
-		 */
-		smp_mb();
-		curr->task = NULL;
-		wake_up_process(task);
-	}
-
-	mm->core_state = NULL;
-}
-
 /*
  * set_dumpable converts traditional three-value dumpable to two flags and
  * stores them into mm->flags.  It modifies lower two bits of mm->flags, but
@@ -1991,7 +1633,7 @@
 	}
 }
  
-static int __get_dumpable(unsigned long mm_flags)
+int __get_dumpable(unsigned long mm_flags)
 {
 	int ret;
  
@@ -2003,289 +1645,4 @@
 {
 	return __get_dumpable(mm->flags);
 }
-
-static void wait_for_dump_helpers(struct file *file)
-{
-	struct pipe_inode_info *pipe;
-
-	pipe = file->f_path.dentry->d_inode->i_pipe;
-
-	pipe_lock(pipe);
-	pipe->readers++;
-	pipe->writers--;
-
-	while ((pipe->readers > 1) && (!signal_pending(current))) {
-		wake_up_interruptible_sync(&pipe->wait);
-		kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
-		pipe_wait(pipe);
-	}
-
-	pipe->readers--;
-	pipe->writers++;
-	pipe_unlock(pipe);
-
-}
-
-
-/*
- * umh_pipe_setup
- * helper function to customize the process used
- * to collect the core in userspace.  Specifically
- * it sets up a pipe and installs it as fd 0 (stdin)
- * for the process.  Returns 0 on success, or
- * PTR_ERR on failure.
- * Note that it also sets the core limit to 1.  This
- * is a special value that we use to trap recursive
- * core dumps
- */
-static int umh_pipe_setup(struct subprocess_info *info, struct cred *new)
-{
-	struct file *files[2];
-	struct coredump_params *cp = (struct coredump_params *)info->data;
-	int err = create_pipe_files(files, 0);
-	if (err)
-		return err;
-
-	cp->file = files[1];
-
-	replace_fd(0, files[0], 0);
-	/* and disallow core files too */
-	current->signal->rlim[RLIMIT_CORE] = (struct rlimit){1, 1};
-
-	return 0;
-}
-
-void do_coredump(long signr, int exit_code, struct pt_regs *regs)
-{
-	struct core_state core_state;
-	struct core_name cn;
-	struct mm_struct *mm = current->mm;
-	struct linux_binfmt * binfmt;
-	const struct cred *old_cred;
-	struct cred *cred;
-	int retval = 0;
-	int flag = 0;
-	int ispipe;
-	struct files_struct *displaced;
-	bool need_nonrelative = false;
-	static atomic_t core_dump_count = ATOMIC_INIT(0);
-	struct coredump_params cprm = {
-		.signr = signr,
-		.regs = regs,
-		.limit = rlimit(RLIMIT_CORE),
-		/*
-		 * We must use the same mm->flags while dumping core to avoid
-		 * inconsistency of bit flags, since this flag is not protected
-		 * by any locks.
-		 */
-		.mm_flags = mm->flags,
-	};
-
-	audit_core_dumps(signr);
-
-	binfmt = mm->binfmt;
-	if (!binfmt || !binfmt->core_dump)
-		goto fail;
-	if (!__get_dumpable(cprm.mm_flags))
-		goto fail;
-
-	cred = prepare_creds();
-	if (!cred)
-		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, and only into a controlled
-	 * environment (pipe handler or fully qualified path).
-	 */
-	if (__get_dumpable(cprm.mm_flags) == SUID_DUMPABLE_SAFE) {
-		/* Setuid core dump mode */
-		flag = O_EXCL;		/* Stop rewrite attacks */
-		cred->fsuid = GLOBAL_ROOT_UID;	/* Dump root private */
-		need_nonrelative = true;
-	}
-
-	retval = coredump_wait(exit_code, &core_state);
-	if (retval < 0)
-		goto fail_creds;
-
-	old_cred = override_creds(cred);
-
-	/*
-	 * 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);
-
-	ispipe = format_corename(&cn, signr);
-
- 	if (ispipe) {
-		int dump_count;
-		char **helper_argv;
-
-		if (ispipe < 0) {
-			printk(KERN_WARNING "format_corename failed\n");
-			printk(KERN_WARNING "Aborting core\n");
-			goto fail_corename;
-		}
-
-		if (cprm.limit == 1) {
-			/* See umh_pipe_setup() which sets RLIMIT_CORE = 1.
-			 *
-			 * Normally core limits are irrelevant to pipes, since
-			 * we're not writing to the file system, but we use
-			 * cprm.limit of 1 here as a speacial value, this is a
-			 * consistent way to catch recursive crashes.
-			 * We can still crash if the core_pattern binary sets
-			 * RLIM_CORE = !1, but it runs as root, and can do
-			 * lots of stupid things.
-			 *
-			 * Note that we use task_tgid_vnr here to grab the pid
-			 * of the process group leader.  That way we get the
-			 * right pid if a thread in a multi-threaded
-			 * core_pattern process dies.
-			 */
-			printk(KERN_WARNING
-				"Process %d(%s) has RLIMIT_CORE set to 1\n",
-				task_tgid_vnr(current), current->comm);
-			printk(KERN_WARNING "Aborting core\n");
-			goto fail_unlock;
-		}
-		cprm.limit = RLIM_INFINITY;
-
-		dump_count = atomic_inc_return(&core_dump_count);
-		if (core_pipe_limit && (core_pipe_limit < dump_count)) {
-			printk(KERN_WARNING "Pid %d(%s) over core_pipe_limit\n",
-			       task_tgid_vnr(current), current->comm);
-			printk(KERN_WARNING "Skipping core dump\n");
-			goto fail_dropcount;
-		}
-
-		helper_argv = argv_split(GFP_KERNEL, cn.corename+1, NULL);
-		if (!helper_argv) {
-			printk(KERN_WARNING "%s failed to allocate memory\n",
-			       __func__);
-			goto fail_dropcount;
-		}
-
-		retval = call_usermodehelper_fns(helper_argv[0], helper_argv,
-					NULL, UMH_WAIT_EXEC, umh_pipe_setup,
-					NULL, &cprm);
-		argv_free(helper_argv);
-		if (retval) {
- 			printk(KERN_INFO "Core dump to %s pipe failed\n",
-			       cn.corename);
-			goto close_fail;
- 		}
-	} else {
-		struct inode *inode;
-
-		if (cprm.limit < binfmt->min_coredump)
-			goto fail_unlock;
-
-		if (need_nonrelative && cn.corename[0] != '/') {
-			printk(KERN_WARNING "Pid %d(%s) can only dump core "\
-				"to fully qualified path!\n",
-				task_tgid_vnr(current), current->comm);
-			printk(KERN_WARNING "Skipping core dump\n");
-			goto fail_unlock;
-		}
-
-		cprm.file = filp_open(cn.corename,
-				 O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag,
-				 0600);
-		if (IS_ERR(cprm.file))
-			goto fail_unlock;
-
-		inode = cprm.file->f_path.dentry->d_inode;
-		if (inode->i_nlink > 1)
-			goto close_fail;
-		if (d_unhashed(cprm.file->f_path.dentry))
-			goto close_fail;
-		/*
-		 * AK: actually i see no reason to not allow this for named
-		 * pipes etc, but keep the previous behaviour for now.
-		 */
-		if (!S_ISREG(inode->i_mode))
-			goto close_fail;
-		/*
-		 * Dont allow local users get cute and trick others to coredump
-		 * into their pre-created files.
-		 */
-		if (!uid_eq(inode->i_uid, current_fsuid()))
-			goto close_fail;
-		if (!cprm.file->f_op || !cprm.file->f_op->write)
-			goto close_fail;
-		if (do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file))
-			goto close_fail;
-	}
-
-	/* get us an unshared descriptor table; almost always a no-op */
-	retval = unshare_files(&displaced);
-	if (retval)
-		goto close_fail;
-	if (displaced)
-		put_files_struct(displaced);
-	retval = binfmt->core_dump(&cprm);
-	if (retval)
-		current->signal->group_exit_code |= 0x80;
-
-	if (ispipe && core_pipe_limit)
-		wait_for_dump_helpers(cprm.file);
-close_fail:
-	if (cprm.file)
-		filp_close(cprm.file, NULL);
-fail_dropcount:
-	if (ispipe)
-		atomic_dec(&core_dump_count);
-fail_unlock:
-	kfree(cn.corename);
-fail_corename:
-	coredump_finish(mm);
-	revert_creds(old_cred);
-fail_creds:
-	put_cred(cred);
-fail:
-	return;
-}
-
-/*
- * Core dumping helper functions.  These are the only things you should
- * do on a core-file: use only these functions to write out all the
- * necessary info.
- */
-int dump_write(struct file *file, const void *addr, int nr)
-{
-	return access_ok(VERIFY_READ, addr, nr) && file->f_op->write(file, addr, nr, &file->f_pos) == nr;
-}
-EXPORT_SYMBOL(dump_write);
-
-int dump_seek(struct file *file, loff_t off)
-{
-	int ret = 1;
-
-	if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
-		if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
-			return 0;
-	} else {
-		char *buf = (char *)get_zeroed_page(GFP_KERNEL);
-
-		if (!buf)
-			return 0;
-		while (off > 0) {
-			unsigned long n = off;
-
-			if (n > PAGE_SIZE)
-				n = PAGE_SIZE;
-			if (!dump_write(file, buf, n)) {
-				ret = 0;
-				break;
-			}
-			off -= n;
-		}
-		free_page((unsigned long)buf);
-	}
-	return ret;
-}
-EXPORT_SYMBOL(dump_seek);
@@ -405,6 +405,7 @@
  
 extern void set_dumpable(struct mm_struct *mm, int value);
 extern int get_dumpable(struct mm_struct *mm);
+extern int __get_dumpable(unsigned long mm_flags);
  
 /* get/set_dumpable() values */
 #define SUID_DUMPABLE_DISABLED	0
...	...	@@ -11,7 +11,7 @@
11	11	attr.o bad_inode.o file.o filesystems.o namespace.o \
12	12	seq_file.o xattr.o libfs.o fs-writeback.o \
13	13	pnode.o drop_caches.o splice.o sync.o utimes.o \
14		- stack.o fs_struct.o statfs.o
	14	+ stack.o fs_struct.o statfs.o coredump.o
15	15
16	16	ifeq ($(CONFIG_BLOCK),y)
17	17	obj-y += buffer.o bio.o block_dev.o direct-io.o mpage.o ioprio.o
	1	+#include <linux/slab.h>
	2	+#include <linux/file.h>
	3	+#include <linux/fdtable.h>
	4	+#include <linux/mm.h>
	5	+#include <linux/stat.h>
	6	+#include <linux/fcntl.h>
	7	+#include <linux/swap.h>
	8	+#include <linux/string.h>
	9	+#include <linux/init.h>
	10	+#include <linux/pagemap.h>
	11	+#include <linux/perf_event.h>
	12	+#include <linux/highmem.h>
	13	+#include <linux/spinlock.h>
	14	+#include <linux/key.h>
	15	+#include <linux/personality.h>
	16	+#include <linux/binfmts.h>
	17	+#include <linux/utsname.h>
	18	+#include <linux/pid_namespace.h>
	19	+#include <linux/module.h>
	20	+#include <linux/namei.h>
	21	+#include <linux/mount.h>
	22	+#include <linux/security.h>
	23	+#include <linux/syscalls.h>
	24	+#include <linux/tsacct_kern.h>
	25	+#include <linux/cn_proc.h>
	26	+#include <linux/audit.h>
	27	+#include <linux/tracehook.h>
	28	+#include <linux/kmod.h>
	29	+#include <linux/fsnotify.h>
	30	+#include <linux/fs_struct.h>
	31	+#include <linux/pipe_fs_i.h>
	32	+#include <linux/oom.h>
	33	+#include <linux/compat.h>
	34	+
	35	+#include <asm/uaccess.h>
	36	+#include <asm/mmu_context.h>
	37	+#include <asm/tlb.h>
	38	+#include <asm/exec.h>
	39	+
	40	+#include <trace/events/task.h>
	41	+#include "internal.h"
	42	+
	43	+#include <trace/events/sched.h>
	44	+
	45	+int core_uses_pid;
	46	+char core_pattern[CORENAME_MAX_SIZE] = "core";
	47	+unsigned int core_pipe_limit;
	48	+
	49	+struct core_name {
	50	+ char *corename;
	51	+ int used, size;
	52	+};
	53	+static atomic_t call_count = ATOMIC_INIT(1);
	54	+
	55	+/* The maximal length of core_pattern is also specified in sysctl.c */
	56	+
	57	+static int expand_corename(struct core_name *cn)
	58	+{
	59	+ char *old_corename = cn->corename;
	60	+
	61	+ cn->size = CORENAME_MAX_SIZE * atomic_inc_return(&call_count);
	62	+ cn->corename = krealloc(old_corename, cn->size, GFP_KERNEL);
	63	+
	64	+ if (!cn->corename) {
	65	+ kfree(old_corename);
	66	+ return -ENOMEM;
	67	+ }
	68	+
	69	+ return 0;
	70	+}
	71	+
	72	+static int cn_printf(struct core_name cn, const char fmt, ...)
	73	+{
	74	+ char *cur;
	75	+ int need;
	76	+ int ret;
	77	+ va_list arg;
	78	+
	79	+ va_start(arg, fmt);
	80	+ need = vsnprintf(NULL, 0, fmt, arg);
	81	+ va_end(arg);
	82	+
	83	+ if (likely(need < cn->size - cn->used - 1))
	84	+ goto out_printf;
	85	+
	86	+ ret = expand_corename(cn);
	87	+ if (ret)
	88	+ goto expand_fail;
	89	+
	90	+out_printf:
	91	+ cur = cn->corename + cn->used;
	92	+ va_start(arg, fmt);
	93	+ vsnprintf(cur, need + 1, fmt, arg);
	94	+ va_end(arg);
	95	+ cn->used += need;
	96	+ return 0;
	97	+
	98	+expand_fail:
	99	+ return ret;
	100	+}
	101	+
	102	+static void cn_escape(char *str)
	103	+{
	104	+ for (; *str; str++)
	105	+ if (*str == '/')
	106	+ *str = '!';
	107	+}
	108	+
	109	+static int cn_print_exe_file(struct core_name *cn)
	110	+{
	111	+ struct file *exe_file;
	112	+ char pathbuf, path;
	113	+ int ret;
	114	+
	115	+ exe_file = get_mm_exe_file(current->mm);
	116	+ if (!exe_file) {
	117	+ char *commstart = cn->corename + cn->used;
	118	+ ret = cn_printf(cn, "%s (path unknown)", current->comm);
	119	+ cn_escape(commstart);
	120	+ return ret;
	121	+ }
	122	+
	123	+ pathbuf = kmalloc(PATH_MAX, GFP_TEMPORARY);
	124	+ if (!pathbuf) {
	125	+ ret = -ENOMEM;
	126	+ goto put_exe_file;
	127	+ }
	128	+
	129	+ path = d_path(&exe_file->f_path, pathbuf, PATH_MAX);
	130	+ if (IS_ERR(path)) {
	131	+ ret = PTR_ERR(path);
	132	+ goto free_buf;
	133	+ }
	134	+
	135	+ cn_escape(path);
	136	+
	137	+ ret = cn_printf(cn, "%s", path);
	138	+
	139	+free_buf:
	140	+ kfree(pathbuf);
	141	+put_exe_file:
	142	+ fput(exe_file);
	143	+ return ret;
	144	+}
	145	+
	146	+/* format_corename will inspect the pattern parameter, and output a
	147	+ * name into corename, which must have space for at least
	148	+ * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator.
	149	+ */
	150	+static int format_corename(struct core_name *cn, long signr)
	151	+{
	152	+ const struct cred *cred = current_cred();
	153	+ const char *pat_ptr = core_pattern;
	154	+ int ispipe = (*pat_ptr == '\|');
	155	+ int pid_in_pattern = 0;
	156	+ int err = 0;
	157	+
	158	+ cn->size = CORENAME_MAX_SIZE * atomic_read(&call_count);
	159	+ cn->corename = kmalloc(cn->size, GFP_KERNEL);
	160	+ cn->used = 0;
	161	+
	162	+ if (!cn->corename)
	163	+ return -ENOMEM;
	164	+
	165	+ /* Repeat as long as we have more pattern to process and more output
	166	+ space */
	167	+ while (*pat_ptr) {
	168	+ if (*pat_ptr != '%') {
	169	+ if (*pat_ptr == 0)
	170	+ goto out;
	171	+ err = cn_printf(cn, "%c", *pat_ptr++);
	172	+ } else {
	173	+ switch (*++pat_ptr) {
	174	+ /* single % at the end, drop that */
	175	+ case 0:
	176	+ goto out;
	177	+ /* Double percent, output one percent */
	178	+ case '%':
	179	+ err = cn_printf(cn, "%c", '%');
	180	+ break;
	181	+ /* pid */
	182	+ case 'p':
	183	+ pid_in_pattern = 1;
	184	+ err = cn_printf(cn, "%d",
	185	+ task_tgid_vnr(current));
	186	+ break;
	187	+ /* uid */
	188	+ case 'u':
	189	+ err = cn_printf(cn, "%d", cred->uid);
	190	+ break;
	191	+ /* gid */
	192	+ case 'g':
	193	+ err = cn_printf(cn, "%d", cred->gid);
	194	+ break;
	195	+ /* signal that caused the coredump */
	196	+ case 's':
	197	+ err = cn_printf(cn, "%ld", signr);
	198	+ break;
	199	+ /* UNIX time of coredump */
	200	+ case 't': {
	201	+ struct timeval tv;
	202	+ do_gettimeofday(&tv);
	203	+ err = cn_printf(cn, "%lu", tv.tv_sec);
	204	+ break;
	205	+ }
	206	+ /* hostname */
	207	+ case 'h': {
	208	+ char *namestart = cn->corename + cn->used;
	209	+ down_read(&uts_sem);
	210	+ err = cn_printf(cn, "%s",
	211	+ utsname()->nodename);
	212	+ up_read(&uts_sem);
	213	+ cn_escape(namestart);
	214	+ break;
	215	+ }
	216	+ /* executable */
	217	+ case 'e': {
	218	+ char *commstart = cn->corename + cn->used;
	219	+ err = cn_printf(cn, "%s", current->comm);
	220	+ cn_escape(commstart);
	221	+ break;
	222	+ }
	223	+ case 'E':
	224	+ err = cn_print_exe_file(cn);
	225	+ break;
	226	+ /* core limit size */
	227	+ case 'c':
	228	+ err = cn_printf(cn, "%lu",
	229	+ rlimit(RLIMIT_CORE));
	230	+ break;
	231	+ default:
	232	+ break;
	233	+ }
	234	+ ++pat_ptr;
	235	+ }
	236	+
	237	+ if (err)
	238	+ return err;
	239	+ }
	240	+
	241	+ /* Backward compatibility with core_uses_pid:
	242	+ *
	243	+ * If core_pattern does not include a %p (as is the default)
	244	+ * and core_uses_pid is set, then .%pid will be appended to
	245	+ * the filename. Do not do this for piped commands. */
	246	+ if (!ispipe && !pid_in_pattern && core_uses_pid) {
	247	+ err = cn_printf(cn, ".%d", task_tgid_vnr(current));
	248	+ if (err)
	249	+ return err;
	250	+ }
	251	+out:
	252	+ return ispipe;
	253	+}
	254	+
	255	+static int zap_process(struct task_struct *start, int exit_code)
	256	+{
	257	+ struct task_struct *t;
	258	+ int nr = 0;
	259	+
	260	+ start->signal->flags = SIGNAL_GROUP_EXIT;
	261	+ start->signal->group_exit_code = exit_code;
	262	+ start->signal->group_stop_count = 0;
	263	+
	264	+ t = start;
	265	+ do {
	266	+ task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK);
	267	+ if (t != current && t->mm) {
	268	+ sigaddset(&t->pending.signal, SIGKILL);
	269	+ signal_wake_up(t, 1);
	270	+ nr++;
	271	+ }
	272	+ } while_each_thread(start, t);
	273	+
	274	+ return nr;
	275	+}
	276	+
	277	+static inline int zap_threads(struct task_struct tsk, struct mm_struct mm,
	278	+ struct core_state *core_state, int exit_code)
	279	+{
	280	+ struct task_struct g, p;
	281	+ unsigned long flags;
	282	+ int nr = -EAGAIN;
	283	+
	284	+ spin_lock_irq(&tsk->sighand->siglock);
	285	+ if (!signal_group_exit(tsk->signal)) {
	286	+ mm->core_state = core_state;
	287	+ nr = zap_process(tsk, exit_code);
	288	+ }
	289	+ spin_unlock_irq(&tsk->sighand->siglock);
	290	+ if (unlikely(nr < 0))
	291	+ return nr;
	292	+
	293	+ if (atomic_read(&mm->mm_users) == nr + 1)
	294	+ goto done;
	295	+ /*
	296	+ * We should find and kill all tasks which use this mm, and we should
	297	+ * count them correctly into ->nr_threads. We don't take tasklist
	298	+ * lock, but this is safe wrt:
	299	+ *
	300	+ * fork:
	301	+ * None of sub-threads can fork after zap_process(leader). All
	302	+ * processes which were created before this point should be
	303	+ * visible to zap_threads() because copy_process() adds the new
	304	+ * process to the tail of init_task.tasks list, and lock/unlock
	305	+ * of ->siglock provides a memory barrier.
	306	+ *
	307	+ * do_exit:
	308	+ * The caller holds mm->mmap_sem. This means that the task which
	309	+ * uses this mm can't pass exit_mm(), so it can't exit or clear
	310	+ * its ->mm.
	311	+ *
	312	+ * de_thread:
	313	+ * It does list_replace_rcu(&leader->tasks, &current->tasks),
	314	+ * we must see either old or new leader, this does not matter.
	315	+ * However, it can change p->sighand, so lock_task_sighand(p)
	316	+ * must be used. Since p->mm != NULL and we hold ->mmap_sem
	317	+ * it can't fail.
	318	+ *
	319	+ * Note also that "g" can be the old leader with ->mm == NULL
	320	+ * and already unhashed and thus removed from ->thread_group.
	321	+ * This is OK, __unhash_process()->list_del_rcu() does not
	322	+ * clear the ->next pointer, we will find the new leader via
	323	+ * next_thread().
	324	+ */
	325	+ rcu_read_lock();
	326	+ for_each_process(g) {
	327	+ if (g == tsk->group_leader)
	328	+ continue;
	329	+ if (g->flags & PF_KTHREAD)
	330	+ continue;
	331	+ p = g;
	332	+ do {
	333	+ if (p->mm) {
	334	+ if (unlikely(p->mm == mm)) {
	335	+ lock_task_sighand(p, &flags);
	336	+ nr += zap_process(p, exit_code);
	337	+ unlock_task_sighand(p, &flags);
	338	+ }
	339	+ break;
	340	+ }
	341	+ } while_each_thread(g, p);
	342	+ }
	343	+ rcu_read_unlock();
	344	+done:
	345	+ atomic_set(&core_state->nr_threads, nr);
	346	+ return nr;
	347	+}
	348	+
	349	+static int coredump_wait(int exit_code, struct core_state *core_state)
	350	+{
	351	+ struct task_struct *tsk = current;
	352	+ struct mm_struct *mm = tsk->mm;
	353	+ int core_waiters = -EBUSY;
	354	+
	355	+ init_completion(&core_state->startup);
	356	+ core_state->dumper.task = tsk;
	357	+ core_state->dumper.next = NULL;
	358	+
	359	+ down_write(&mm->mmap_sem);
	360	+ if (!mm->core_state)
	361	+ core_waiters = zap_threads(tsk, mm, core_state, exit_code);
	362	+ up_write(&mm->mmap_sem);
	363	+
	364	+ if (core_waiters > 0) {
	365	+ struct core_thread *ptr;
	366	+
	367	+ wait_for_completion(&core_state->startup);
	368	+ /*
	369	+ * Wait for all the threads to become inactive, so that
	370	+ * all the thread context (extended register state, like
	371	+ * fpu etc) gets copied to the memory.
	372	+ */
	373	+ ptr = core_state->dumper.next;
	374	+ while (ptr != NULL) {
	375	+ wait_task_inactive(ptr->task, 0);
	376	+ ptr = ptr->next;
	377	+ }
	378	+ }
	379	+
	380	+ return core_waiters;
	381	+}
	382	+
	383	+static void coredump_finish(struct mm_struct *mm)
	384	+{
	385	+ struct core_thread curr, next;
	386	+ struct task_struct *task;
	387	+
	388	+ next = mm->core_state->dumper.next;
	389	+ while ((curr = next) != NULL) {
	390	+ next = curr->next;
	391	+ task = curr->task;
	392	+ /*
	393	+ * see exit_mm(), curr->task must not see
	394	+ * ->task == NULL before we read ->next.
	395	+ */
	396	+ smp_mb();
	397	+ curr->task = NULL;
	398	+ wake_up_process(task);
	399	+ }
	400	+
	401	+ mm->core_state = NULL;
	402	+}
	403	+
	404	+static void wait_for_dump_helpers(struct file *file)
	405	+{
	406	+ struct pipe_inode_info *pipe;
	407	+
	408	+ pipe = file->f_path.dentry->d_inode->i_pipe;
	409	+
	410	+ pipe_lock(pipe);
	411	+ pipe->readers++;
	412	+ pipe->writers--;
	413	+
	414	+ while ((pipe->readers > 1) && (!signal_pending(current))) {
	415	+ wake_up_interruptible_sync(&pipe->wait);
	416	+ kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
	417	+ pipe_wait(pipe);
	418	+ }
	419	+
	420	+ pipe->readers--;
	421	+ pipe->writers++;
	422	+ pipe_unlock(pipe);
	423	+
	424	+}
	425	+
	426	+/*
	427	+ * umh_pipe_setup
	428	+ * helper function to customize the process used
	429	+ * to collect the core in userspace. Specifically
	430	+ * it sets up a pipe and installs it as fd 0 (stdin)
	431	+ * for the process. Returns 0 on success, or
	432	+ * PTR_ERR on failure.
	433	+ * Note that it also sets the core limit to 1. This
	434	+ * is a special value that we use to trap recursive
	435	+ * core dumps
	436	+ */
	437	+static int umh_pipe_setup(struct subprocess_info info, struct cred new)
	438	+{
	439	+ struct file *files[2];
	440	+ struct coredump_params cp = (struct coredump_params )info->data;
	441	+ int err = create_pipe_files(files, 0);
	442	+ if (err)
	443	+ return err;
	444	+
	445	+ cp->file = files[1];
	446	+
	447	+ replace_fd(0, files[0], 0);
	448	+ /* and disallow core files too */
	449	+ current->signal->rlim[RLIMIT_CORE] = (struct rlimit){1, 1};
	450	+
	451	+ return 0;
	452	+}
	453	+
	454	+void do_coredump(long signr, int exit_code, struct pt_regs *regs)
	455	+{
	456	+ struct core_state core_state;
	457	+ struct core_name cn;
	458	+ struct mm_struct *mm = current->mm;
	459	+ struct linux_binfmt * binfmt;
	460	+ const struct cred *old_cred;
	461	+ struct cred *cred;
	462	+ int retval = 0;
	463	+ int flag = 0;
	464	+ int ispipe;
	465	+ struct files_struct *displaced;
	466	+ bool need_nonrelative = false;
	467	+ static atomic_t core_dump_count = ATOMIC_INIT(0);
	468	+ struct coredump_params cprm = {
	469	+ .signr = signr,
	470	+ .regs = regs,
	471	+ .limit = rlimit(RLIMIT_CORE),
	472	+ /*
	473	+ * We must use the same mm->flags while dumping core to avoid
	474	+ * inconsistency of bit flags, since this flag is not protected
	475	+ * by any locks.
	476	+ */
	477	+ .mm_flags = mm->flags,
	478	+ };
	479	+
	480	+ audit_core_dumps(signr);
	481	+
	482	+ binfmt = mm->binfmt;
	483	+ if (!binfmt \|\| !binfmt->core_dump)
	484	+ goto fail;
	485	+ if (!__get_dumpable(cprm.mm_flags))
	486	+ goto fail;
	487	+
	488	+ cred = prepare_creds();
	489	+ if (!cred)
	490	+ goto fail;
	491	+ /*
	492	+ * We cannot trust fsuid as being the "true" uid of the process
	493	+ * nor do we know its entire history. We only know it was tainted
	494	+ * so we dump it as root in mode 2, and only into a controlled
	495	+ * environment (pipe handler or fully qualified path).
	496	+ */
	497	+ if (__get_dumpable(cprm.mm_flags) == SUID_DUMPABLE_SAFE) {
	498	+ /* Setuid core dump mode */
	499	+ flag = O_EXCL; /* Stop rewrite attacks */
	500	+ cred->fsuid = GLOBAL_ROOT_UID; /* Dump root private */
	501	+ need_nonrelative = true;
	502	+ }
	503	+
	504	+ retval = coredump_wait(exit_code, &core_state);
	505	+ if (retval < 0)
	506	+ goto fail_creds;
	507	+
	508	+ old_cred = override_creds(cred);
	509	+
	510	+ /*
	511	+ * Clear any false indication of pending signals that might
	512	+ * be seen by the filesystem code called to write the core file.
	513	+ */
	514	+ clear_thread_flag(TIF_SIGPENDING);
	515	+
	516	+ ispipe = format_corename(&cn, signr);
	517	+
	518	+ if (ispipe) {
	519	+ int dump_count;
	520	+ char **helper_argv;
	521	+
	522	+ if (ispipe < 0) {
	523	+ printk(KERN_WARNING "format_corename failed\n");
	524	+ printk(KERN_WARNING "Aborting core\n");
	525	+ goto fail_corename;
	526	+ }
	527	+
	528	+ if (cprm.limit == 1) {
	529	+ /* See umh_pipe_setup() which sets RLIMIT_CORE = 1.
	530	+ *
	531	+ * Normally core limits are irrelevant to pipes, since
	532	+ * we're not writing to the file system, but we use
	533	+ * cprm.limit of 1 here as a speacial value, this is a
	534	+ * consistent way to catch recursive crashes.
	535	+ * We can still crash if the core_pattern binary sets
	536	+ * RLIM_CORE = !1, but it runs as root, and can do
	537	+ * lots of stupid things.
	538	+ *
	539	+ * Note that we use task_tgid_vnr here to grab the pid
	540	+ * of the process group leader. That way we get the
	541	+ * right pid if a thread in a multi-threaded
	542	+ * core_pattern process dies.
	543	+ */
	544	+ printk(KERN_WARNING
	545	+ "Process %d(%s) has RLIMIT_CORE set to 1\n",
	546	+ task_tgid_vnr(current), current->comm);
	547	+ printk(KERN_WARNING "Aborting core\n");
	548	+ goto fail_unlock;
	549	+ }
	550	+ cprm.limit = RLIM_INFINITY;
	551	+
	552	+ dump_count = atomic_inc_return(&core_dump_count);
	553	+ if (core_pipe_limit && (core_pipe_limit < dump_count)) {
	554	+ printk(KERN_WARNING "Pid %d(%s) over core_pipe_limit\n",
	555	+ task_tgid_vnr(current), current->comm);
	556	+ printk(KERN_WARNING "Skipping core dump\n");
	557	+ goto fail_dropcount;
	558	+ }
	559	+
	560	+ helper_argv = argv_split(GFP_KERNEL, cn.corename+1, NULL);
	561	+ if (!helper_argv) {
	562	+ printk(KERN_WARNING "%s failed to allocate memory\n",
	563	+ __func__);
	564	+ goto fail_dropcount;
	565	+ }
	566	+
	567	+ retval = call_usermodehelper_fns(helper_argv[0], helper_argv,
	568	+ NULL, UMH_WAIT_EXEC, umh_pipe_setup,
	569	+ NULL, &cprm);
	570	+ argv_free(helper_argv);
	571	+ if (retval) {
	572	+ printk(KERN_INFO "Core dump to %s pipe failed\n",
	573	+ cn.corename);
	574	+ goto close_fail;
	575	+ }
	576	+ } else {
	577	+ struct inode *inode;
	578	+
	579	+ if (cprm.limit < binfmt->min_coredump)
	580	+ goto fail_unlock;
	581	+
	582	+ if (need_nonrelative && cn.corename[0] != '/') {
	583	+ printk(KERN_WARNING "Pid %d(%s) can only dump core "\
	584	+ "to fully qualified path!\n",
	585	+ task_tgid_vnr(current), current->comm);
	586	+ printk(KERN_WARNING "Skipping core dump\n");
	587	+ goto fail_unlock;
	588	+ }
	589	+
	590	+ cprm.file = filp_open(cn.corename,
	591	+ O_CREAT \| 2 \| O_NOFOLLOW \| O_LARGEFILE \| flag,
	592	+ 0600);
	593	+ if (IS_ERR(cprm.file))
	594	+ goto fail_unlock;
	595	+
	596	+ inode = cprm.file->f_path.dentry->d_inode;
	597	+ if (inode->i_nlink > 1)
	598	+ goto close_fail;
	599	+ if (d_unhashed(cprm.file->f_path.dentry))
	600	+ goto close_fail;
	601	+ /*
	602	+ * AK: actually i see no reason to not allow this for named
	603	+ * pipes etc, but keep the previous behaviour for now.
	604	+ */
	605	+ if (!S_ISREG(inode->i_mode))
	606	+ goto close_fail;
	607	+ /*
	608	+ * Dont allow local users get cute and trick others to coredump
	609	+ * into their pre-created files.
	610	+ */
	611	+ if (!uid_eq(inode->i_uid, current_fsuid()))
	612	+ goto close_fail;
	613	+ if (!cprm.file->f_op \|\| !cprm.file->f_op->write)
	614	+ goto close_fail;
	615	+ if (do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file))
	616	+ goto close_fail;
	617	+ }
	618	+
	619	+ /* get us an unshared descriptor table; almost always a no-op */
	620	+ retval = unshare_files(&displaced);
	621	+ if (retval)
	622	+ goto close_fail;
	623	+ if (displaced)
	624	+ put_files_struct(displaced);
	625	+ retval = binfmt->core_dump(&cprm);
	626	+ if (retval)
	627	+ current->signal->group_exit_code \|= 0x80;
	628	+
	629	+ if (ispipe && core_pipe_limit)
	630	+ wait_for_dump_helpers(cprm.file);
	631	+close_fail:
	632	+ if (cprm.file)
	633	+ filp_close(cprm.file, NULL);
	634	+fail_dropcount:
	635	+ if (ispipe)
	636	+ atomic_dec(&core_dump_count);
	637	+fail_unlock:
	638	+ kfree(cn.corename);
	639	+fail_corename:
	640	+ coredump_finish(mm);
	641	+ revert_creds(old_cred);
	642	+fail_creds:
	643	+ put_cred(cred);
	644	+fail:
	645	+ return;
	646	+}
	647	+
	648	+/*
	649	+ * Core dumping helper functions. These are the only things you should
	650	+ * do on a core-file: use only these functions to write out all the
	651	+ * necessary info.
	652	+ */
	653	+int dump_write(struct file file, const void addr, int nr)
	654	+{
	655	+ return access_ok(VERIFY_READ, addr, nr) && file->f_op->write(file, addr, nr, &file->f_pos) == nr;
	656	+}
	657	+EXPORT_SYMBOL(dump_write);
	658	+
	659	+int dump_seek(struct file *file, loff_t off)
	660	+{
	661	+ int ret = 1;
	662	+
	663	+ if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
	664	+ if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
	665	+ return 0;
	666	+ } else {
	667	+ char buf = (char )get_zeroed_page(GFP_KERNEL);
	668	+
	669	+ if (!buf)
	670	+ return 0;
	671	+ while (off > 0) {
	672	+ unsigned long n = off;
	673	+
	674	+ if (n > PAGE_SIZE)
	675	+ n = PAGE_SIZE;
	676	+ if (!dump_write(file, buf, n)) {
	677	+ ret = 0;
	678	+ break;
	679	+ }
	680	+ off -= n;
	681	+ }
	682	+ free_page((unsigned long)buf);
	683	+ }
	684	+ return ret;
	685	+}
	686	+EXPORT_SYMBOL(dump_seek);
...	...	@@ -66,19 +66,8 @@
66	66
67	67	#include <trace/events/sched.h>
68	68
69		-int core_uses_pid;
70		-char core_pattern[CORENAME_MAX_SIZE] = "core";
71		-unsigned int core_pipe_limit;
72	69	int suid_dumpable = 0;
73	70
74		-struct core_name {
75		- char *corename;
76		- int used, size;
77		-};
78		-static atomic_t call_count = ATOMIC_INIT(1);
79		-
80		-/* The maximal length of core_pattern is also specified in sysctl.c */
81		-
82	71	static LIST_HEAD(formats);
83	72	static DEFINE_RWLOCK(binfmt_lock);
84	73
...	...	@@ -1603,353 +1592,6 @@
1603	1592
1604	1593	EXPORT_SYMBOL(set_binfmt);
1605	1594
1606		-static int expand_corename(struct core_name *cn)
1607		-{
1608		- char *old_corename = cn->corename;
1609		-
1610		- cn->size = CORENAME_MAX_SIZE * atomic_inc_return(&call_count);
1611		- cn->corename = krealloc(old_corename, cn->size, GFP_KERNEL);
1612		-
1613		- if (!cn->corename) {
1614		- kfree(old_corename);
1615		- return -ENOMEM;
1616		- }
1617		-
1618		- return 0;
1619		-}
1620		-
1621		-static int cn_printf(struct core_name cn, const char fmt, ...)
1622		-{
1623		- char *cur;
1624		- int need;
1625		- int ret;
1626		- va_list arg;
1627		-
1628		- va_start(arg, fmt);
1629		- need = vsnprintf(NULL, 0, fmt, arg);
1630		- va_end(arg);
1631		-
1632		- if (likely(need < cn->size - cn->used - 1))
1633		- goto out_printf;
1634		-
1635		- ret = expand_corename(cn);
1636		- if (ret)
1637		- goto expand_fail;
1638		-
1639		-out_printf:
1640		- cur = cn->corename + cn->used;
1641		- va_start(arg, fmt);
1642		- vsnprintf(cur, need + 1, fmt, arg);
1643		- va_end(arg);
1644		- cn->used += need;
1645		- return 0;
1646		-
1647		-expand_fail:
1648		- return ret;
1649		-}
1650		-
1651		-static void cn_escape(char *str)
1652		-{
1653		- for (; *str; str++)
1654		- if (*str == '/')
1655		- *str = '!';
1656		-}
1657		-
1658		-static int cn_print_exe_file(struct core_name *cn)
1659		-{
1660		- struct file *exe_file;
1661		- char pathbuf, path;
1662		- int ret;
1663		-
1664		- exe_file = get_mm_exe_file(current->mm);
1665		- if (!exe_file) {
1666		- char *commstart = cn->corename + cn->used;
1667		- ret = cn_printf(cn, "%s (path unknown)", current->comm);
1668		- cn_escape(commstart);
1669		- return ret;
1670		- }
1671		-
1672		- pathbuf = kmalloc(PATH_MAX, GFP_TEMPORARY);
1673		- if (!pathbuf) {
1674		- ret = -ENOMEM;
1675		- goto put_exe_file;
1676		- }
1677		-
1678		- path = d_path(&exe_file->f_path, pathbuf, PATH_MAX);
1679		- if (IS_ERR(path)) {
1680		- ret = PTR_ERR(path);
1681		- goto free_buf;
1682		- }
1683		-
1684		- cn_escape(path);
1685		-
1686		- ret = cn_printf(cn, "%s", path);
1687		-
1688		-free_buf:
1689		- kfree(pathbuf);
1690		-put_exe_file:
1691		- fput(exe_file);
1692		- return ret;
1693		-}
1694		-
1695		-/* format_corename will inspect the pattern parameter, and output a
1696		- * name into corename, which must have space for at least
1697		- * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator.
1698		- */
1699		-static int format_corename(struct core_name *cn, long signr)
1700		-{
1701		- const struct cred *cred = current_cred();
1702		- const char *pat_ptr = core_pattern;
1703		- int ispipe = (*pat_ptr == '\|');
1704		- int pid_in_pattern = 0;
1705		- int err = 0;
1706		-
1707		- cn->size = CORENAME_MAX_SIZE * atomic_read(&call_count);
1708		- cn->corename = kmalloc(cn->size, GFP_KERNEL);
1709		- cn->used = 0;
1710		-
1711		- if (!cn->corename)
1712		- return -ENOMEM;
1713		-
1714		- /* Repeat as long as we have more pattern to process and more output
1715		- space */
1716		- while (*pat_ptr) {
1717		- if (*pat_ptr != '%') {
1718		- if (*pat_ptr == 0)
1719		- goto out;
1720		- err = cn_printf(cn, "%c", *pat_ptr++);
1721		- } else {
1722		- switch (*++pat_ptr) {
1723		- /* single % at the end, drop that */
1724		- case 0:
1725		- goto out;
1726		- /* Double percent, output one percent */
1727		- case '%':
1728		- err = cn_printf(cn, "%c", '%');
1729		- break;
1730		- /* pid */
1731		- case 'p':
1732		- pid_in_pattern = 1;
1733		- err = cn_printf(cn, "%d",
1734		- task_tgid_vnr(current));
1735		- break;
1736		- /* uid */
1737		- case 'u':
1738		- err = cn_printf(cn, "%d", cred->uid);
1739		- break;
1740		- /* gid */
1741		- case 'g':
1742		- err = cn_printf(cn, "%d", cred->gid);
1743		- break;
1744		- /* signal that caused the coredump */
1745		- case 's':
1746		- err = cn_printf(cn, "%ld", signr);
1747		- break;
1748		- /* UNIX time of coredump */
1749		- case 't': {
1750		- struct timeval tv;
1751		- do_gettimeofday(&tv);
1752		- err = cn_printf(cn, "%lu", tv.tv_sec);
1753		- break;
1754		- }
1755		- /* hostname */
1756		- case 'h': {
1757		- char *namestart = cn->corename + cn->used;
1758		- down_read(&uts_sem);
1759		- err = cn_printf(cn, "%s",
1760		- utsname()->nodename);
1761		- up_read(&uts_sem);
1762		- cn_escape(namestart);
1763		- break;
1764		- }
1765		- /* executable */
1766		- case 'e': {
1767		- char *commstart = cn->corename + cn->used;
1768		- err = cn_printf(cn, "%s", current->comm);
1769		- cn_escape(commstart);
1770		- break;
1771		- }
1772		- case 'E':
1773		- err = cn_print_exe_file(cn);
1774		- break;
1775		- /* core limit size */
1776		- case 'c':
1777		- err = cn_printf(cn, "%lu",
1778		- rlimit(RLIMIT_CORE));
1779		- break;
1780		- default:
1781		- break;
1782		- }
1783		- ++pat_ptr;
1784		- }
1785		-
1786		- if (err)
1787		- return err;
1788		- }
1789		-
1790		- /* Backward compatibility with core_uses_pid:
1791		- *
1792		- * If core_pattern does not include a %p (as is the default)
1793		- * and core_uses_pid is set, then .%pid will be appended to
1794		- * the filename. Do not do this for piped commands. */
1795		- if (!ispipe && !pid_in_pattern && core_uses_pid) {
1796		- err = cn_printf(cn, ".%d", task_tgid_vnr(current));
1797		- if (err)
1798		- return err;
1799		- }
1800		-out:
1801		- return ispipe;
1802		-}
1803		-
1804		-static int zap_process(struct task_struct *start, int exit_code)
1805		-{
1806		- struct task_struct *t;
1807		- int nr = 0;
1808		-
1809		- start->signal->flags = SIGNAL_GROUP_EXIT;
1810		- start->signal->group_exit_code = exit_code;
1811		- start->signal->group_stop_count = 0;
1812		-
1813		- t = start;
1814		- do {
1815		- task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK);
1816		- if (t != current && t->mm) {
1817		- sigaddset(&t->pending.signal, SIGKILL);
1818		- signal_wake_up(t, 1);
1819		- nr++;
1820		- }
1821		- } while_each_thread(start, t);
1822		-
1823		- return nr;
1824		-}
1825		-
1826		-static inline int zap_threads(struct task_struct tsk, struct mm_struct mm,
1827		- struct core_state *core_state, int exit_code)
1828		-{
1829		- struct task_struct g, p;
1830		- unsigned long flags;
1831		- int nr = -EAGAIN;
1832		-
1833		- spin_lock_irq(&tsk->sighand->siglock);
1834		- if (!signal_group_exit(tsk->signal)) {
1835		- mm->core_state = core_state;
1836		- nr = zap_process(tsk, exit_code);
1837		- }
1838		- spin_unlock_irq(&tsk->sighand->siglock);
1839		- if (unlikely(nr < 0))
1840		- return nr;
1841		-
1842		- if (atomic_read(&mm->mm_users) == nr + 1)
1843		- goto done;
1844		- /*
1845		- * We should find and kill all tasks which use this mm, and we should
1846		- * count them correctly into ->nr_threads. We don't take tasklist
1847		- * lock, but this is safe wrt:
1848		- *
1849		- * fork:
1850		- * None of sub-threads can fork after zap_process(leader). All
1851		- * processes which were created before this point should be
1852		- * visible to zap_threads() because copy_process() adds the new
1853		- * process to the tail of init_task.tasks list, and lock/unlock
1854		- * of ->siglock provides a memory barrier.
1855		- *
1856		- * do_exit:
1857		- * The caller holds mm->mmap_sem. This means that the task which
1858		- * uses this mm can't pass exit_mm(), so it can't exit or clear
1859		- * its ->mm.
1860		- *
1861		- * de_thread:
1862		- * It does list_replace_rcu(&leader->tasks, &current->tasks),
1863		- * we must see either old or new leader, this does not matter.
1864		- * However, it can change p->sighand, so lock_task_sighand(p)
1865		- * must be used. Since p->mm != NULL and we hold ->mmap_sem
1866		- * it can't fail.
1867		- *
1868		- * Note also that "g" can be the old leader with ->mm == NULL
1869		- * and already unhashed and thus removed from ->thread_group.
1870		- * This is OK, __unhash_process()->list_del_rcu() does not
1871		- * clear the ->next pointer, we will find the new leader via
1872		- * next_thread().
1873		- */
1874		- rcu_read_lock();
1875		- for_each_process(g) {
1876		- if (g == tsk->group_leader)
1877		- continue;
1878		- if (g->flags & PF_KTHREAD)
1879		- continue;
1880		- p = g;
1881		- do {
1882		- if (p->mm) {
1883		- if (unlikely(p->mm == mm)) {
1884		- lock_task_sighand(p, &flags);
1885		- nr += zap_process(p, exit_code);
1886		- unlock_task_sighand(p, &flags);
1887		- }
1888		- break;
1889		- }
1890		- } while_each_thread(g, p);
1891		- }
1892		- rcu_read_unlock();
1893		-done:
1894		- atomic_set(&core_state->nr_threads, nr);
1895		- return nr;
1896		-}
1897		-
1898		-static int coredump_wait(int exit_code, struct core_state *core_state)
1899		-{
1900		- struct task_struct *tsk = current;
1901		- struct mm_struct *mm = tsk->mm;
1902		- int core_waiters = -EBUSY;
1903		-
1904		- init_completion(&core_state->startup);
1905		- core_state->dumper.task = tsk;
1906		- core_state->dumper.next = NULL;
1907		-
1908		- down_write(&mm->mmap_sem);
1909		- if (!mm->core_state)
1910		- core_waiters = zap_threads(tsk, mm, core_state, exit_code);
1911		- up_write(&mm->mmap_sem);
1912		-
1913		- if (core_waiters > 0) {
1914		- struct core_thread *ptr;
1915		-
1916		- wait_for_completion(&core_state->startup);
1917		- /*
1918		- * Wait for all the threads to become inactive, so that
1919		- * all the thread context (extended register state, like
1920		- * fpu etc) gets copied to the memory.
1921		- */
1922		- ptr = core_state->dumper.next;
1923		- while (ptr != NULL) {
1924		- wait_task_inactive(ptr->task, 0);
1925		- ptr = ptr->next;
1926		- }
1927		- }
1928		-
1929		- return core_waiters;
1930		-}
1931		-
1932		-static void coredump_finish(struct mm_struct *mm)
1933		-{
1934		- struct core_thread curr, next;
1935		- struct task_struct *task;
1936		-
1937		- next = mm->core_state->dumper.next;
1938		- while ((curr = next) != NULL) {
1939		- next = curr->next;
1940		- task = curr->task;
1941		- /*
1942		- * see exit_mm(), curr->task must not see
1943		- * ->task == NULL before we read ->next.
1944		- */
1945		- smp_mb();
1946		- curr->task = NULL;
1947		- wake_up_process(task);
1948		- }
1949		-
1950		- mm->core_state = NULL;
1951		-}
1952		-
1953	1595	/*
1954	1596	* set_dumpable converts traditional three-value dumpable to two flags and
1955	1597	* stores them into mm->flags. It modifies lower two bits of mm->flags, but
...	...	@@ -1991,7 +1633,7 @@
1991	1633	}
1992	1634	}
1993	1635
1994		-static int __get_dumpable(unsigned long mm_flags)
	1636	+int __get_dumpable(unsigned long mm_flags)
1995	1637	{
1996	1638	int ret;
1997	1639
...	...	@@ -2003,289 +1645,4 @@
2003	1645	{
2004	1646	return __get_dumpable(mm->flags);
2005	1647	}
2006		-
2007		-static void wait_for_dump_helpers(struct file *file)
2008		-{
2009		- struct pipe_inode_info *pipe;
2010		-
2011		- pipe = file->f_path.dentry->d_inode->i_pipe;
2012		-
2013		- pipe_lock(pipe);
2014		- pipe->readers++;
2015		- pipe->writers--;
2016		-
2017		- while ((pipe->readers > 1) && (!signal_pending(current))) {
2018		- wake_up_interruptible_sync(&pipe->wait);
2019		- kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
2020		- pipe_wait(pipe);
2021		- }
2022		-
2023		- pipe->readers--;
2024		- pipe->writers++;
2025		- pipe_unlock(pipe);
2026		-
2027		-}
2028		-
2029		-
2030		-/*
2031		- * umh_pipe_setup
2032		- * helper function to customize the process used
2033		- * to collect the core in userspace. Specifically
2034		- * it sets up a pipe and installs it as fd 0 (stdin)
2035		- * for the process. Returns 0 on success, or
2036		- * PTR_ERR on failure.
2037		- * Note that it also sets the core limit to 1. This
2038		- * is a special value that we use to trap recursive
2039		- * core dumps
2040		- */
2041		-static int umh_pipe_setup(struct subprocess_info info, struct cred new)
2042		-{
2043		- struct file *files[2];
2044		- struct coredump_params cp = (struct coredump_params )info->data;
2045		- int err = create_pipe_files(files, 0);
2046		- if (err)
2047		- return err;
2048		-
2049		- cp->file = files[1];
2050		-
2051		- replace_fd(0, files[0], 0);
2052		- /* and disallow core files too */
2053		- current->signal->rlim[RLIMIT_CORE] = (struct rlimit){1, 1};
2054		-
2055		- return 0;
2056		-}
2057		-
2058		-void do_coredump(long signr, int exit_code, struct pt_regs *regs)
2059		-{
2060		- struct core_state core_state;
2061		- struct core_name cn;
2062		- struct mm_struct *mm = current->mm;
2063		- struct linux_binfmt * binfmt;
2064		- const struct cred *old_cred;
2065		- struct cred *cred;
2066		- int retval = 0;
2067		- int flag = 0;
2068		- int ispipe;
2069		- struct files_struct *displaced;
2070		- bool need_nonrelative = false;
2071		- static atomic_t core_dump_count = ATOMIC_INIT(0);
2072		- struct coredump_params cprm = {
2073		- .signr = signr,
2074		- .regs = regs,
2075		- .limit = rlimit(RLIMIT_CORE),
2076		- /*
2077		- * We must use the same mm->flags while dumping core to avoid
2078		- * inconsistency of bit flags, since this flag is not protected
2079		- * by any locks.
2080		- */
2081		- .mm_flags = mm->flags,
2082		- };
2083		-
2084		- audit_core_dumps(signr);
2085		-
2086		- binfmt = mm->binfmt;
2087		- if (!binfmt \|\| !binfmt->core_dump)
2088		- goto fail;
2089		- if (!__get_dumpable(cprm.mm_flags))
2090		- goto fail;
2091		-
2092		- cred = prepare_creds();
2093		- if (!cred)
2094		- goto fail;
2095		- /*
2096		- * We cannot trust fsuid as being the "true" uid of the process
2097		- * nor do we know its entire history. We only know it was tainted
2098		- * so we dump it as root in mode 2, and only into a controlled
2099		- * environment (pipe handler or fully qualified path).
2100		- */
2101		- if (__get_dumpable(cprm.mm_flags) == SUID_DUMPABLE_SAFE) {
2102		- /* Setuid core dump mode */
2103		- flag = O_EXCL; /* Stop rewrite attacks */
2104		- cred->fsuid = GLOBAL_ROOT_UID; /* Dump root private */
2105		- need_nonrelative = true;
2106		- }
2107		-
2108		- retval = coredump_wait(exit_code, &core_state);
2109		- if (retval < 0)
2110		- goto fail_creds;
2111		-
2112		- old_cred = override_creds(cred);
2113		-
2114		- /*
2115		- * Clear any false indication of pending signals that might
2116		- * be seen by the filesystem code called to write the core file.
2117		- */
2118		- clear_thread_flag(TIF_SIGPENDING);
2119		-
2120		- ispipe = format_corename(&cn, signr);
2121		-
2122		- if (ispipe) {
2123		- int dump_count;
2124		- char **helper_argv;
2125		-
2126		- if (ispipe < 0) {
2127		- printk(KERN_WARNING "format_corename failed\n");
2128		- printk(KERN_WARNING "Aborting core\n");
2129		- goto fail_corename;
2130		- }
2131		-
2132		- if (cprm.limit == 1) {
2133		- /* See umh_pipe_setup() which sets RLIMIT_CORE = 1.
2134		- *
2135		- * Normally core limits are irrelevant to pipes, since
2136		- * we're not writing to the file system, but we use
2137		- * cprm.limit of 1 here as a speacial value, this is a
2138		- * consistent way to catch recursive crashes.
2139		- * We can still crash if the core_pattern binary sets
2140		- * RLIM_CORE = !1, but it runs as root, and can do
2141		- * lots of stupid things.
2142		- *
2143		- * Note that we use task_tgid_vnr here to grab the pid
2144		- * of the process group leader. That way we get the
2145		- * right pid if a thread in a multi-threaded
2146		- * core_pattern process dies.
2147		- */
2148		- printk(KERN_WARNING
2149		- "Process %d(%s) has RLIMIT_CORE set to 1\n",
2150		- task_tgid_vnr(current), current->comm);
2151		- printk(KERN_WARNING "Aborting core\n");
2152		- goto fail_unlock;
2153		- }
2154		- cprm.limit = RLIM_INFINITY;
2155		-
2156		- dump_count = atomic_inc_return(&core_dump_count);
2157		- if (core_pipe_limit && (core_pipe_limit < dump_count)) {
2158		- printk(KERN_WARNING "Pid %d(%s) over core_pipe_limit\n",
2159		- task_tgid_vnr(current), current->comm);
2160		- printk(KERN_WARNING "Skipping core dump\n");
2161		- goto fail_dropcount;
2162		- }
2163		-
2164		- helper_argv = argv_split(GFP_KERNEL, cn.corename+1, NULL);
2165		- if (!helper_argv) {
2166		- printk(KERN_WARNING "%s failed to allocate memory\n",
2167		- __func__);
2168		- goto fail_dropcount;
2169		- }
2170		-
2171		- retval = call_usermodehelper_fns(helper_argv[0], helper_argv,
2172		- NULL, UMH_WAIT_EXEC, umh_pipe_setup,
2173		- NULL, &cprm);
2174		- argv_free(helper_argv);
2175		- if (retval) {
2176		- printk(KERN_INFO "Core dump to %s pipe failed\n",
2177		- cn.corename);
2178		- goto close_fail;
2179		- }
2180		- } else {
2181		- struct inode *inode;
2182		-
2183		- if (cprm.limit < binfmt->min_coredump)
2184		- goto fail_unlock;
2185		-
2186		- if (need_nonrelative && cn.corename[0] != '/') {
2187		- printk(KERN_WARNING "Pid %d(%s) can only dump core "\
2188		- "to fully qualified path!\n",
2189		- task_tgid_vnr(current), current->comm);
2190		- printk(KERN_WARNING "Skipping core dump\n");
2191		- goto fail_unlock;
2192		- }
2193		-
2194		- cprm.file = filp_open(cn.corename,
2195		- O_CREAT \| 2 \| O_NOFOLLOW \| O_LARGEFILE \| flag,
2196		- 0600);
2197		- if (IS_ERR(cprm.file))
2198		- goto fail_unlock;
2199		-
2200		- inode = cprm.file->f_path.dentry->d_inode;
2201		- if (inode->i_nlink > 1)
2202		- goto close_fail;
2203		- if (d_unhashed(cprm.file->f_path.dentry))
2204		- goto close_fail;
2205		- /*
2206		- * AK: actually i see no reason to not allow this for named
2207		- * pipes etc, but keep the previous behaviour for now.
2208		- */
2209		- if (!S_ISREG(inode->i_mode))
2210		- goto close_fail;
2211		- /*
2212		- * Dont allow local users get cute and trick others to coredump
2213		- * into their pre-created files.
2214		- */
2215		- if (!uid_eq(inode->i_uid, current_fsuid()))
2216		- goto close_fail;
2217		- if (!cprm.file->f_op \|\| !cprm.file->f_op->write)
2218		- goto close_fail;
2219		- if (do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file))
2220		- goto close_fail;
2221		- }
2222		-
2223		- /* get us an unshared descriptor table; almost always a no-op */
2224		- retval = unshare_files(&displaced);
2225		- if (retval)
2226		- goto close_fail;
2227		- if (displaced)
2228		- put_files_struct(displaced);
2229		- retval = binfmt->core_dump(&cprm);
2230		- if (retval)
2231		- current->signal->group_exit_code \|= 0x80;
2232		-
2233		- if (ispipe && core_pipe_limit)
2234		- wait_for_dump_helpers(cprm.file);
2235		-close_fail:
2236		- if (cprm.file)
2237		- filp_close(cprm.file, NULL);
2238		-fail_dropcount:
2239		- if (ispipe)
2240		- atomic_dec(&core_dump_count);
2241		-fail_unlock:
2242		- kfree(cn.corename);
2243		-fail_corename:
2244		- coredump_finish(mm);
2245		- revert_creds(old_cred);
2246		-fail_creds:
2247		- put_cred(cred);
2248		-fail:
2249		- return;
2250		-}
2251		-
2252		-/*
2253		- * Core dumping helper functions. These are the only things you should
2254		- * do on a core-file: use only these functions to write out all the
2255		- * necessary info.
2256		- */
2257		-int dump_write(struct file file, const void addr, int nr)
2258		-{
2259		- return access_ok(VERIFY_READ, addr, nr) && file->f_op->write(file, addr, nr, &file->f_pos) == nr;
2260		-}
2261		-EXPORT_SYMBOL(dump_write);
2262		-
2263		-int dump_seek(struct file *file, loff_t off)
2264		-{
2265		- int ret = 1;
2266		-
2267		- if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
2268		- if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
2269		- return 0;
2270		- } else {
2271		- char buf = (char )get_zeroed_page(GFP_KERNEL);
2272		-
2273		- if (!buf)
2274		- return 0;
2275		- while (off > 0) {
2276		- unsigned long n = off;
2277		-
2278		- if (n > PAGE_SIZE)
2279		- n = PAGE_SIZE;
2280		- if (!dump_write(file, buf, n)) {
2281		- ret = 0;
2282		- break;
2283		- }
2284		- off -= n;
2285		- }
2286		- free_page((unsigned long)buf);
2287		- }
2288		- return ret;
2289		-}
2290		-EXPORT_SYMBOL(dump_seek);
...	...	@@ -405,6 +405,7 @@
405	405
406	406	extern void set_dumpable(struct mm_struct *mm, int value);
407	407	extern int get_dumpable(struct mm_struct *mm);
	408	+extern int __get_dumpable(unsigned long mm_flags);
408	409
409	410	/* get/set_dumpable() values */
410	411	#define SUID_DUMPABLE_DISABLED 0