/*
 * FUSE: Filesystem in Userspace
 * Copyright (C) 2016 Canonical Ltd. <seth.forshee@canonical.com>
 *
 * This program can be distributed under the terms of the GNU GPL.
 * See the file COPYING.
 */

#include "fuse_i.h"

#include <linux/posix_acl.h>
#include <linux/posix_acl_xattr.h>

struct posix_acl *fuse_get_acl(struct inode *inode, int type)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	int size;
	const char *name;
	void *value = NULL;
	struct posix_acl *acl;

	if (!fc->posix_acl || fc->no_getxattr)
		return NULL;

	if (type == ACL_TYPE_ACCESS)
		name = XATTR_NAME_POSIX_ACL_ACCESS;
	else if (type == ACL_TYPE_DEFAULT)
		name = XATTR_NAME_POSIX_ACL_DEFAULT;
	else
		return ERR_PTR(-EOPNOTSUPP);

	value = kmalloc(PAGE_SIZE, GFP_KERNEL);
	if (!value)
		return ERR_PTR(-ENOMEM);
	size = fuse_getxattr(inode, name, value, PAGE_SIZE);
	if (size > 0)
		acl = posix_acl_from_xattr(&init_user_ns, value, size);
	else if ((size == 0) || (size == -ENODATA) ||
		 (size == -EOPNOTSUPP && fc->no_getxattr))
		acl = NULL;
	else if (size == -ERANGE)
		acl = ERR_PTR(-E2BIG);
	else
		acl = ERR_PTR(size);

	kfree(value);
	return acl;
}

int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	const char *name;
	int ret;

	if (!fc->posix_acl || fc->no_setxattr)
		return -EOPNOTSUPP;

	if (type == ACL_TYPE_ACCESS)
		name = XATTR_NAME_POSIX_ACL_ACCESS;
	else if (type == ACL_TYPE_DEFAULT)
		name = XATTR_NAME_POSIX_ACL_DEFAULT;
	else
		return -EINVAL;

	if (acl) {
		/*
		 * Fuse userspace is responsible for updating access
		 * permissions in the inode, if needed. fuse_setxattr
		 * invalidates the inode attributes, which will force
		 * them to be refreshed the next time they are used,
		 * and it also updates i_ctime.
		 */
		size_t size = posix_acl_xattr_size(acl->a_count);
		void *value;

		if (size > PAGE_SIZE)
			return -E2BIG;

		value = kmalloc(size, GFP_KERNEL);
		if (!value)
			return -ENOMEM;

		ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
		if (ret < 0) {
			kfree(value);
			return ret;
		}

		ret = fuse_setxattr(inode, name, value, size, 0);
		kfree(value);
	} else {
		ret = fuse_removexattr(inode, name);
	}
	forget_all_cached_acls(inode);
	fuse_invalidate_attr(inode);

	return ret;
}
7ac649326f'>diff</a></td><td class='form'><form class='right' method='get' action='/cgit.cgi/linux/net-next.git/log/net/sctp/debug.c'>
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<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>net</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/sctp?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>sctp</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/sctp/debug.c?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>debug.c</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='bf29bddf0417a4783da3b24e8c9e017ac649326f'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='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>Jiri Kosina &lt;jkosina@suse.cz&gt;</td><td class='right'>2017-01-27 22:25:52 +0000</td></tr>
<tr><th>committer</th><td>Ingo Molnar &lt;mingo@kernel.org&gt;</td><td class='right'>2017-01-28 09:18:56 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/sctp/debug.c?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>bf29bddf0417a4783da3b24e8c9e017ac649326f</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/sctp/debug.c?id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>54a05a4883b73f80e4e1d8c4b15750aa01c39932</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/sctp/debug.c?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>net/sctp/debug.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/sctp/debug.c?h=nds-private-remove&amp;id=883af14e67e8b8702b5560aa64c888c0cd0bd66c'>883af14e67e8b8702b5560aa64c888c0cd0bd66c</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/sctp/debug.c?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f&amp;id2=883af14e67e8b8702b5560aa64c888c0cd0bd66c'>diff</a>)</td></tr></table>
<div class='commit-subject'>x86/efi: Always map the first physical page into the EFI pagetables</div><div class='commit-msg'>Commit:

  129766708 ("x86/efi: Only map RAM into EFI page tables if in mixed-mode")

stopped creating 1:1 mappings for all RAM, when running in native 64-bit mode.

It turns out though that there are 64-bit EFI implementations in the wild
(this particular problem has been reported on a Lenovo Yoga 710-11IKB),
which still make use of the first physical page for their own private use,
even though they explicitly mark it EFI_CONVENTIONAL_MEMORY in the memory
map.

In case there is no mapping for this particular frame in the EFI pagetables,
as soon as firmware tries to make use of it, a triple fault occurs and the
system reboots (in case of the Yoga 710-11IKB this is very early during bootup).

Fix that by always mapping the first page of physical memory into the EFI
pagetables. We're free to hand this page to the BIOS, as trim_bios_range()
will reserve the first page and isolate it away from memory allocators anyway.

Note that just reverting 129766708 alone is not enough on v4.9-rc1+ to fix the
regression on affected hardware, as this commit:

   ab72a27da ("x86/efi: Consolidate region mapping logic")

later made the first physical frame not to be mapped anyway.

Reported-by: Hanka Pavlikova &lt;hanka@ucw.cz&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
Signed-off-by: Matt Fleming &lt;matt@codeblueprint.co.uk&gt;
Cc: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Borislav Petkov &lt;bp@suse.de&gt;
Cc: Laura Abbott &lt;labbott@redhat.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vojtech Pavlik &lt;vojtech@ucw.cz&gt;
Cc: Waiman Long &lt;waiman.long@hpe.com&gt;
Cc: linux-efi@vger.kernel.org
Cc: stable@kernel.org # v4.8+
Fixes: 129766708 ("x86/efi: Only map RAM into EFI page tables if in mixed-mode")
Link: http://lkml.kernel.org/r/20170127222552.22336-1-matt@codeblueprint.co.uk
[ Tidied up the changelog and the comment. ]
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>Diffstat</a> (limited to 'net/sctp/debug.c')</div><table summary='diffstat' class='diffstat'>