X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=fs%2Fproc%2Fbase.c;h=fcf02f2deeba398f790a4657574cfcbed9b55bc9;hb=25a025863e024f6b86b48137b10b4960c50351b0;hp=9a4da0aae02e442e5be76fa84a0907a43e1bf848;hpb=577f99c1d08cf9cbdafd4e858dd13ff04d855090;p=linux-2.6

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 9a4da0aae0..fcf02f2dee 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -195,12 +195,32 @@ static int proc_root_link(struct inode *inode, struct path *path)
 	return result;
 }
 
-#define MAY_PTRACE(task) \
-	(task == current || \
-	(task->parent == current && \
-	(task->ptrace & PT_PTRACED) && \
-	 (task_is_stopped_or_traced(task)) && \
-	 security_ptrace(current,task) == 0))
+/*
+ * Return zero if current may access user memory in @task, -error if not.
+ */
+static int check_mem_permission(struct task_struct *task)
+{
+	/*
+	 * A task can always look at itself, in case it chooses
+	 * to use system calls instead of load instructions.
+	 */
+	if (task == current)
+		return 0;
+
+	/*
+	 * If current is actively ptrace'ing, and would also be
+	 * permitted to freshly attach with ptrace now, permit it.
+	 */
+	if (task->parent == current && (task->ptrace & PT_PTRACED) &&
+	    task_is_stopped_or_traced(task) &&
+	    ptrace_may_attach(task))
+		return 0;
+
+	/*
+	 * Noone else is allowed.
+	 */
+	return -EPERM;
+}
 
 struct mm_struct *mm_for_maps(struct task_struct *task)
 {
@@ -502,17 +522,14 @@ static const struct inode_operations proc_def_inode_operations = {
 	.setattr	= proc_setattr,
 };
 
-extern const struct seq_operations mounts_op;
-struct proc_mounts {
-	struct seq_file m;
-	int event;
-};
-
-static int mounts_open(struct inode *inode, struct file *file)
+static int mounts_open_common(struct inode *inode, struct file *file,
+			      const struct seq_operations *op)
 {
 	struct task_struct *task = get_proc_task(inode);
 	struct nsproxy *nsp;
 	struct mnt_namespace *ns = NULL;
+	struct fs_struct *fs = NULL;
+	struct path root;
 	struct proc_mounts *p;
 	int ret = -EINVAL;
 
@@ -525,40 +542,61 @@ static int mounts_open(struct inode *inode, struct file *file)
 				get_mnt_ns(ns);
 		}
 		rcu_read_unlock();
-
+		if (ns)
+			fs = get_fs_struct(task);
 		put_task_struct(task);
 	}
 
-	if (ns) {
-		ret = -ENOMEM;
-		p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
-		if (p) {
-			file->private_data = &p->m;
-			ret = seq_open(file, &mounts_op);
-			if (!ret) {
-				p->m.private = ns;
-				p->event = ns->event;
-				return 0;
-			}
-			kfree(p);
-		}
-		put_mnt_ns(ns);
-	}
+	if (!ns)
+		goto err;
+	if (!fs)
+		goto err_put_ns;
+
+	read_lock(&fs->lock);
+	root = fs->root;
+	path_get(&root);
+	read_unlock(&fs->lock);
+	put_fs_struct(fs);
+
+	ret = -ENOMEM;
+	p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
+	if (!p)
+		goto err_put_path;
+
+	file->private_data = &p->m;
+	ret = seq_open(file, op);
+	if (ret)
+		goto err_free;
+
+	p->m.private = p;
+	p->ns = ns;
+	p->root = root;
+	p->event = ns->event;
+
+	return 0;
+
+ err_free:
+	kfree(p);
+ err_put_path:
+	path_put(&root);
+ err_put_ns:
+	put_mnt_ns(ns);
+ err:
 	return ret;
 }
 
 static int mounts_release(struct inode *inode, struct file *file)
 {
-	struct seq_file *m = file->private_data;
-	struct mnt_namespace *ns = m->private;
-	put_mnt_ns(ns);
+	struct proc_mounts *p = file->private_data;
+	path_put(&p->root);
+	put_mnt_ns(p->ns);
 	return seq_release(inode, file);
 }
 
 static unsigned mounts_poll(struct file *file, poll_table *wait)
 {
 	struct proc_mounts *p = file->private_data;
-	struct mnt_namespace *ns = p->m.private;
+	struct mnt_namespace *ns = p->ns;
 	unsigned res = 0;
 
 	poll_wait(file, &ns->poll, wait);
@@ -573,6 +611,11 @@ static unsigned mounts_poll(struct file *file, poll_table *wait)
 	return res;
 }
 
+static int mounts_open(struct inode *inode, struct file *file)
+{
+	return mounts_open_common(inode, file, &mounts_op);
+}
+
 static const struct file_operations proc_mounts_operations = {
 	.open		= mounts_open,
 	.read		= seq_read,
@@ -581,38 +624,22 @@ static const struct file_operations proc_mounts_operations = {
 	.poll		= mounts_poll,
 };
 
-extern const struct seq_operations mountstats_op;
-static int mountstats_open(struct inode *inode, struct file *file)
+static int mountinfo_open(struct inode *inode, struct file *file)
 {
-	int ret = seq_open(file, &mountstats_op);
-
-	if (!ret) {
-		struct seq_file *m = file->private_data;
-		struct nsproxy *nsp;
-		struct mnt_namespace *mnt_ns = NULL;
-		struct task_struct *task = get_proc_task(inode);
-
-		if (task) {
-			rcu_read_lock();
-			nsp = task_nsproxy(task);
-			if (nsp) {
-				mnt_ns = nsp->mnt_ns;
-				if (mnt_ns)
-					get_mnt_ns(mnt_ns);
-			}
-			rcu_read_unlock();
+	return mounts_open_common(inode, file, &mountinfo_op);
+}
 
-			put_task_struct(task);
-		}
+static const struct file_operations proc_mountinfo_operations = {
+	.open		= mountinfo_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= mounts_release,
+	.poll		= mounts_poll,
+};
 
-		if (mnt_ns)
-			m->private = mnt_ns;
-		else {
-			seq_release(inode, file);
-			ret = -EINVAL;
-		}
-	}
-	return ret;
+static int mountstats_open(struct inode *inode, struct file *file)
+{
+	return mounts_open_common(inode, file, &mountstats_op);
 }
 
 static const struct file_operations proc_mountstats_operations = {
@@ -715,7 +742,7 @@ static ssize_t mem_read(struct file * file, char __user * buf,
 	if (!task)
 		goto out_no_task;
 
-	if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
+	if (check_mem_permission(task))
 		goto out;
 
 	ret = -ENOMEM;
@@ -741,7 +768,7 @@ static ssize_t mem_read(struct file * file, char __user * buf,
 
 		this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
 		retval = access_process_vm(task, src, page, this_len, 0);
-		if (!retval || !MAY_PTRACE(task) || !ptrace_may_attach(task)) {
+		if (!retval || check_mem_permission(task)) {
 			if (!ret)
 				ret = -EIO;
 			break;
@@ -785,7 +812,7 @@ static ssize_t mem_write(struct file * file, const char __user *buf,
 	if (!task)
 		goto out_no_task;
 
-	if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
+	if (check_mem_permission(task))
 		goto out;
 
 	copied = -ENOMEM;
@@ -1036,6 +1063,26 @@ static const struct file_operations proc_loginuid_operations = {
 	.read		= proc_loginuid_read,
 	.write		= proc_loginuid_write,
 };
+
+static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
+				  size_t count, loff_t *ppos)
+{
+	struct inode * inode = file->f_path.dentry->d_inode;
+	struct task_struct *task = get_proc_task(inode);
+	ssize_t length;
+	char tmpbuf[TMPBUFLEN];
+
+	if (!task)
+		return -ESRCH;
+	length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
+				audit_get_sessionid(task));
+	put_task_struct(task);
+	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
+}
+
+static const struct file_operations proc_sessionid_operations = {
+	.read		= proc_sessionid_read,
+};
 #endif
 
 #ifdef CONFIG_FAULT_INJECTION
@@ -1154,6 +1201,81 @@ static const struct file_operations proc_pid_sched_operations = {
 
 #endif
 
+/*
+ * We added or removed a vma mapping the executable. The vmas are only mapped
+ * during exec and are not mapped with the mmap system call.
+ * Callers must hold down_write() on the mm's mmap_sem for these
+ */
+void added_exe_file_vma(struct mm_struct *mm)
+{
+	mm->num_exe_file_vmas++;
+}
+
+void removed_exe_file_vma(struct mm_struct *mm)
+{
+	mm->num_exe_file_vmas--;
+	if ((mm->num_exe_file_vmas == 0) && mm->exe_file){
+		fput(mm->exe_file);
+		mm->exe_file = NULL;
+	}
+
+}
+
+void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file)
+{
+	if (new_exe_file)
+		get_file(new_exe_file);
+	if (mm->exe_file)
+		fput(mm->exe_file);
+	mm->exe_file = new_exe_file;
+	mm->num_exe_file_vmas = 0;
+}
+
+struct file *get_mm_exe_file(struct mm_struct *mm)
+{
+	struct file *exe_file;
+
+	/* We need mmap_sem to protect against races with removal of
+	 * VM_EXECUTABLE vmas */
+	down_read(&mm->mmap_sem);
+	exe_file = mm->exe_file;
+	if (exe_file)
+		get_file(exe_file);
+	up_read(&mm->mmap_sem);
+	return exe_file;
+}
+
+void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm)
+{
+	/* It's safe to write the exe_file pointer without exe_file_lock because
+	 * this is called during fork when the task is not yet in /proc */
+	newmm->exe_file = get_mm_exe_file(oldmm);
+}
+
+static int proc_exe_link(struct inode *inode, struct path *exe_path)
+{
+	struct task_struct *task;
+	struct mm_struct *mm;
+	struct file *exe_file;
+
+	task = get_proc_task(inode);
+	if (!task)
+		return -ENOENT;
+	mm = get_task_mm(task);
+	put_task_struct(task);
+	if (!mm)
+		return -ENOENT;
+	exe_file = get_mm_exe_file(mm);
+	mmput(mm);
+	if (exe_file) {
+		*exe_path = exe_file->f_path;
+		path_get(&exe_file->f_path);
+		fput(exe_file);
+		return 0;
+	} else
+		return -ENOENT;
+}
+
 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
 	struct inode *inode = dentry->d_inode;
@@ -1606,7 +1728,6 @@ static int proc_readfd_common(struct file * filp, void * dirent,
 	unsigned int fd, ino;
 	int retval;
 	struct files_struct * files;
-	struct fdtable *fdt;
 
 	retval = -ENOENT;
 	if (!p)
@@ -1629,9 +1750,8 @@ static int proc_readfd_common(struct file * filp, void * dirent,
 			if (!files)
 				goto out;
 			rcu_read_lock();
-			fdt = files_fdtable(files);
 			for (fd = filp->f_pos-2;
-			     fd < fdt->max_fds;
+			     fd < files_fdtable(files)->max_fds;
 			     fd++, filp->f_pos++) {
 				char name[PROC_NUMBUF];
 				int len;
@@ -2270,7 +2390,7 @@ static const struct pid_entry tgid_base_stuff[] = {
 	DIR("fd",         S_IRUSR|S_IXUSR, fd),
 	DIR("fdinfo",     S_IRUSR|S_IXUSR, fdinfo),
 #ifdef CONFIG_NET
-	DIR("net",        S_IRUGO|S_IXUSR, net),
+	DIR("net",        S_IRUGO|S_IXUGO, net),
 #endif
 	REG("environ",    S_IRUSR, environ),
 	INF("auxv",       S_IRUSR, pid_auxv),
@@ -2291,6 +2411,7 @@ static const struct pid_entry tgid_base_stuff[] = {
 	LNK("root",       root),
 	LNK("exe",        exe),
 	REG("mounts",     S_IRUGO, mounts),
+	REG("mountinfo",  S_IRUGO, mountinfo),
 	REG("mountstats", S_IRUSR, mountstats),
 #ifdef CONFIG_PROC_PAGE_MONITOR
 	REG("clear_refs", S_IWUSR, clear_refs),
@@ -2319,6 +2440,7 @@ static const struct pid_entry tgid_base_stuff[] = {
 	REG("oom_adj",    S_IRUGO|S_IWUSR, oom_adjust),
 #ifdef CONFIG_AUDITSYSCALL
 	REG("loginuid",   S_IWUSR|S_IRUGO, loginuid),
+	REG("sessionid",  S_IRUSR, sessionid),
 #endif
 #ifdef CONFIG_FAULT_INJECTION
 	REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
@@ -2622,6 +2744,7 @@ static const struct pid_entry tid_base_stuff[] = {
 	LNK("root",      root),
 	LNK("exe",       exe),
 	REG("mounts",    S_IRUGO, mounts),
+	REG("mountinfo",  S_IRUGO, mountinfo),
 #ifdef CONFIG_PROC_PAGE_MONITOR
 	REG("clear_refs", S_IWUSR, clear_refs),
 	REG("smaps",     S_IRUGO, smaps),
@@ -2649,6 +2772,7 @@ static const struct pid_entry tid_base_stuff[] = {
 	REG("oom_adj",   S_IRUGO|S_IWUSR, oom_adjust),
 #ifdef CONFIG_AUDITSYSCALL
 	REG("loginuid",  S_IWUSR|S_IRUGO, loginuid),
+	REG("sessionid",  S_IRUSR, sessionid),
 #endif
 #ifdef CONFIG_FAULT_INJECTION
 	REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),