/*
 * fs/inotify_user.c - inotify support for userspace
 *
 * Authors:
 *	John McCutchan	<ttb@tentacle.dhs.org>
 *	Robert Love	<rml@novell.com>
 *
 * Copyright (C) 2005 John McCutchan
 * Copyright 2006 Hewlett-Packard Development Company, L.P.
 *
 * Copyright (C) 2009 Eric Paris <Red Hat Inc>
 * inotify was largely rewriten to make use of the fsnotify infrastructure
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 */

#include <linux/dcache.h> /* d_unlinked */
#include <linux/fs.h> /* struct inode */
#include <linux/fsnotify_backend.h>
#include <linux/inotify.h>
#include <linux/path.h> /* struct path */
#include <linux/slab.h> /* kmem_* */
#include <linux/types.h>
#include <linux/sched.h>

#include "inotify.h"

/*
 * Check if 2 events contain the same information.
 */
static bool event_compare(struct fsnotify_event *old_fsn,
			  struct fsnotify_event *new_fsn)
{
	struct inotify_event_info *old, *new;

	if (old_fsn->mask & FS_IN_IGNORED)
		return false;
	old = INOTIFY_E(old_fsn);
	new = INOTIFY_E(new_fsn);
	if ((old_fsn->mask == new_fsn->mask) &&
	    (old_fsn->inode == new_fsn->inode) &&
	    (old->name_len == new->name_len) &&
	    (!old->name_len || !strcmp(old->name, new->name)))
		return true;
	return false;
}

static int inotify_merge(struct list_head *list,
			  struct fsnotify_event *event)
{
	struct fsnotify_event *last_event;

	last_event = list_entry(list->prev, struct fsnotify_event, list);
	return event_compare(last_event, event);
}

int inotify_handle_event(struct fsnotify_group *group,
			 struct inode *inode,
			 struct fsnotify_mark *inode_mark,
			 struct fsnotify_mark *vfsmount_mark,
			 u32 mask, const void *data, int data_type,
			 const unsigned char *file_name, u32 cookie)
{
	struct inotify_inode_mark *i_mark;
	struct inotify_event_info *event;
	struct fsnotify_event *fsn_event;
	int ret;
	int len = 0;
	int alloc_len = sizeof(struct inotify_event_info);

	BUG_ON(vfsmount_mark);

	if ((inode_mark->mask & FS_EXCL_UNLINK) &&
	    (data_type == FSNOTIFY_EVENT_PATH)) {
		const struct path *path = data;

		if (d_unlinked(path->dentry))
			return 0;
	}
	if (file_name) {
		len = strlen(file_name);
		alloc_len += len + 1;
	}

	pr_debug("%s: group=%p inode=%p mask=%x\n", __func__, group, inode,
		 mask);

	i_mark = container_of(inode_mark, struct inotify_inode_mark,
			      fsn_mark);

	event = kmalloc(alloc_len, GFP_KERNEL);
	if (unlikely(!event))
		return -ENOMEM;

	fsn_event = &event->fse;
	fsnotify_init_event(fsn_event, inode, mask);
	event->wd = i_mark->wd;
	event->sync_cookie = cookie;
	event->name_len = len;
	if (len)
		strcpy(event->name, file_name);

	ret = fsnotify_add_event(group, fsn_event, inotify_merge);
	if (ret) {
		/* Our event wasn't used in the end. Free it. */
		fsnotify_destroy_event(group, fsn_event);
	}

	if (inode_mark->mask & IN_ONESHOT)
		fsnotify_destroy_mark(inode_mark, group);

	return 0;
}

static void inotify_freeing_mark(struct fsnotify_mark *fsn_mark, struct fsnotify_group *group)
{
	inotify_ignored_and_remove_idr(fsn_mark, group);
}

/*
 * This is NEVER supposed to be called.  Inotify marks should either have been
 * removed from the idr when the watch was removed or in the
 * fsnotify_destroy_mark_by_group() call when the inotify instance was being
 * torn down.  This is only called if the idr is about to be freed but there
 * are still marks in it.
 */
static int idr_callback(int id, void *p, void *data)
{
	struct fsnotify_mark *fsn_mark;
	struct inotify_inode_mark *i_mark;
	static bool warned = false;

	if (warned)
		return 0;

	warned = true;
	fsn_mark = p;
	i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);

	WARN(1, "inotify closing but id=%d for fsn_mark=%p in group=%p still in "
		"idr.  Probably leaking memory\n", id, p, data);

	/*
	 * I'm taking the liberty of assuming that the mark in question is a
	 * valid address and I'm dereferencing it.  This might help to figure
	 * out why we got here and the panic is no worse than the original
	 * BUG() that was here.
	 */
	if (fsn_mark)
		printk(KERN_WARNING "fsn_mark->group=%p inode=%p wd=%d\n",
			fsn_mark->group, fsn_mark->inode, i_mark->wd);
	return 0;
}

static void inotify_free_group_priv(struct fsnotify_group *group)
{
	/* ideally the idr is empty and we won't hit the BUG in the callback */
	idr_for_each(&group->inotify_data.idr, idr_callback, group);
	idr_destroy(&group->inotify_data.idr);
	if (group->inotify_data.user) {
		atomic_dec(&group->inotify_data.user->inotify_devs);
		free_uid(group->inotify_data.user);
	}
}

static void inotify_free_event(struct fsnotify_event *fsn_event)
{
	kfree(INOTIFY_E(fsn_event));
}

const struct fsnotify_ops inotify_fsnotify_ops = {
	.handle_event = inotify_handle_event,
	.free_group_priv = inotify_free_group_priv,
	.free_event = inotify_free_event,
	.freeing_mark = inotify_freeing_mark,
};
-02-01 21:17:49 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/perf/bench/Build?h=nds-private-remove&amp;id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>c8f325a59cfc718d13a50fbc746ed9b415c25e92</a> (<a href='/cgit.cgi/linux/net-next.git/patch/tools/perf/bench/Build?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>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=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>d53fbdac9d0781e39a13b2ac6b2bd258cf3b4140</a> /<a href='/cgit.cgi/linux/net-next.git/tree/tools/perf/bench/Build?h=nds-private-remove&amp;id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>tools/perf/bench/Build</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/perf/bench/Build?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>bf29bddf0417a4783da3b24e8c9e017ac649326f</a> (<a href='/cgit.cgi/linux/net-next.git/diff/tools/perf/bench/Build?h=nds-private-remove&amp;id=c8f325a59cfc718d13a50fbc746ed9b415c25e92&amp;id2=bf29bddf0417a4783da3b24e8c9e017ac649326f'>diff</a>)</td></tr></table>
<div class='commit-subject'>efi/fdt: Avoid FDT manipulation after ExitBootServices()</div><div class='commit-msg'>Some AArch64 UEFI implementations disable the MMU in ExitBootServices(),
after which unaligned accesses to RAM are no longer supported.

Commit:

  abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel")

fixed an issue in the memory map handling of the stub FDT code, but
inadvertently created an issue with such firmware, by moving some
of the FDT manipulation to after the invocation of ExitBootServices().

Given that the stub's libfdt implementation uses the ordinary, accelerated
string functions, which rely on hardware handling of unaligned accesses,
manipulating the FDT with the MMU off may result in alignment faults.

So fix the situation by moving the update_fdt_memmap() call into the
callback function invoked by efi_exit_boot_services() right before it
calls the ExitBootServices() UEFI service (which is arguably a better
place for it anyway)

Note that disabling the MMU in ExitBootServices() is not compliant with
the UEFI spec, and carries great risk due to the fact that switching from
cached to uncached memory accesses halfway through compiler generated code
(i.e., involving a stack) can never be done in a way that is architecturally
safe.

Fixes: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel")
Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Tested-by: Riku Voipio &lt;riku.voipio@linaro.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Cc: mark.rutland@arm.com
Cc: linux-efi@vger.kernel.org
Cc: matt@codeblueprint.co.uk
Cc: leif.lindholm@linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1485971102-23330-2-git-send-email-ard.biesheuvel@linaro.org
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=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>Diffstat</a> (limited to 'tools/perf/bench/Build')</div><table summary='diffstat' class='diffstat'>