/*
 * Copyright (C) 2012 Red Hat, Inc.
 * Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/efi.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/mount.h>

#include "internal.h"

static ssize_t efivarfs_file_write(struct file *file,
		const char __user *userbuf, size_t count, loff_t *ppos)
{
	struct efivar_entry *var = file->private_data;
	void *data;
	u32 attributes;
	struct inode *inode = file->f_mapping->host;
	unsigned long datasize = count - sizeof(attributes);
	ssize_t bytes;
	bool set = false;

	if (count < sizeof(attributes))
		return -EINVAL;

	if (copy_from_user(&attributes, userbuf, sizeof(attributes)))
		return -EFAULT;

	if (attributes & ~(EFI_VARIABLE_MASK))
		return -EINVAL;

	data = memdup_user(userbuf + sizeof(attributes), datasize);
	if (IS_ERR(data))
		return PTR_ERR(data);

	bytes = efivar_entry_set_get_size(var, attributes, &datasize,
					  data, &set);
	if (!set && bytes) {
		if (bytes == -ENOENT)
			bytes = -EIO;
		goto out;
	}

	if (bytes == -ENOENT) {
		drop_nlink(inode);
		d_delete(file->f_path.dentry);
		dput(file->f_path.dentry);
	} else {
		inode_lock(inode);
		i_size_write(inode, datasize + sizeof(attributes));
		inode_unlock(inode);
	}

	bytes = count;

out:
	kfree(data);

	return bytes;
}

static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
		size_t count, loff_t *ppos)
{
	struct efivar_entry *var = file->private_data;
	unsigned long datasize = 0;
	u32 attributes;
	void *data;
	ssize_t size = 0;
	int err;

	err = efivar_entry_size(var, &datasize);

	/*
	 * efivarfs represents uncommitted variables with
	 * zero-length files. Reading them should return EOF.
	 */
	if (err == -ENOENT)
		return 0;
	else if (err)
		return err;

	data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL);

	if (!data)
		return -ENOMEM;

	size = efivar_entry_get(var, &attributes, &datasize,
				data + sizeof(attributes));
	if (size)
		goto out_free;

	memcpy(data, &attributes, sizeof(attributes));
	size = simple_read_from_buffer(userbuf, count, ppos,
				       data, datasize + sizeof(attributes));
out_free:
	kfree(data);

	return size;
}

static int
efivarfs_ioc_getxflags(struct file *file, void __user *arg)
{
	struct inode *inode = file->f_mapping->host;
	unsigned int i_flags;
	unsigned int flags = 0;

	i_flags = inode->i_flags;
	if (i_flags & S_IMMUTABLE)
		flags |= FS_IMMUTABLE_FL;

	if (copy_to_user(arg, &flags, sizeof(flags)))
		return -EFAULT;
	return 0;
}

static int
efivarfs_ioc_setxflags(struct file *file, void __user *arg)
{
	struct inode *inode = file->f_mapping->host;
	unsigned int flags;
	unsigned int i_flags = 0;
	int error;

	if (!inode_owner_or_capable(inode))
		return -EACCES;

	if (copy_from_user(&flags, arg, sizeof(flags)))
		return -EFAULT;

	if (flags & ~FS_IMMUTABLE_FL)
		return -EOPNOTSUPP;

	if (!capable(CAP_LINUX_IMMUTABLE))
		return -EPERM;

	if (flags & FS_IMMUTABLE_FL)
		i_flags |= S_IMMUTABLE;


	error = mnt_want_write_file(file);
	if (error)
		return error;

	inode_lock(inode);
	inode_set_flags(inode, i_flags, S_IMMUTABLE);
	inode_unlock(inode);

	mnt_drop_write_file(file);

	return 0;
}

static long
efivarfs_file_ioctl(struct file *file, unsigned int cmd, unsigned long p)
{
	void __user *arg = (void __user *)p;

	switch (cmd) {
	case FS_IOC_GETFLAGS:
		return efivarfs_ioc_getxflags(file, arg);
	case FS_IOC_SETFLAGS:
		return efivarfs_ioc_setxflags(file, arg);
	}

	return -ENOTTY;
}

const struct file_operations efivarfs_file_operations = {
	.open	= simple_open,
	.read	= efivarfs_file_read,
	.write	= efivarfs_file_write,
	.llseek	= no_llseek,
	.unlocked_ioctl = efivarfs_file_ioctl,
};
e='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Peter Zijlstra &lt;peterz@infradead.org&gt;</td><td class='right'>2017-01-26 23:15:08 +0100</td></tr>
<tr><th>committer</th><td>Ingo Molnar &lt;mingo@kernel.org&gt;</td><td class='right'>2017-01-30 11:41:26 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/trace/syscall.h?id=0b3589be9b98994ce3d5aeca52445d1f5627c4ba'>0b3589be9b98994ce3d5aeca52445d1f5627c4ba</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include/trace/syscall.h?id=0b3589be9b98994ce3d5aeca52445d1f5627c4ba'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=0b3589be9b98994ce3d5aeca52445d1f5627c4ba'>85d0d9b3ac902af2c938b19a566884caf8d00323</a> /<a href='/cgit.cgi/linux/net-next.git/tree/include/trace/syscall.h?id=0b3589be9b98994ce3d5aeca52445d1f5627c4ba'>include/trace/syscall.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/trace/syscall.h?id=a76a82a3e38c8d3fb6499e3dfaeb0949241ab588'>a76a82a3e38c8d3fb6499e3dfaeb0949241ab588</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/trace/syscall.h?id=0b3589be9b98994ce3d5aeca52445d1f5627c4ba&amp;id2=a76a82a3e38c8d3fb6499e3dfaeb0949241ab588'>diff</a>)</td></tr></table>
<div class='commit-subject'>perf/core: Fix PERF_RECORD_MMAP2 prot/flags for anonymous memory</div><div class='commit-msg'>Andres reported that MMAP2 records for anonymous memory always have
their protection field 0.

Turns out, someone daft put the prot/flags generation code in the file
branch, leaving them unset for anonymous memory.

Reported-by: Andres Freund &lt;andres@anarazel.de&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Don Zickus &lt;dzickus@redhat.com
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Stephane Eranian &lt;eranian@gmail.com&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: acme@kernel.org
Cc: anton@ozlabs.org
Cc: namhyung@kernel.org
Cc: stable@vger.kernel.org # v3.16+
Fixes: f972eb63b100 ("perf: Pass protection and flags bits through mmap2 interface")
Link: http://lkml.kernel.org/r/20170126221508.GF6536@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=0b3589be9b98994ce3d5aeca52445d1f5627c4ba'>Diffstat</a> (limited to 'include/trace/syscall.h')</div><table summary='diffstat' class='diffstat'>