/*
 * Software async multibuffer crypto daemon headers
 *
 *    Author:
 *             Tim Chen <tim.c.chen@linux.intel.com>
 *
 *    Copyright (c) 2014, Intel Corporation.
 */

#ifndef _CRYPTO_MCRYPT_H
#define _CRYPTO_MCRYPT_H

#include <linux/crypto.h>
#include <linux/kernel.h>
#include <crypto/hash.h>

struct mcryptd_ahash {
	struct crypto_ahash base;
};

static inline struct mcryptd_ahash *__mcryptd_ahash_cast(
	struct crypto_ahash *tfm)
{
	return (struct mcryptd_ahash *)tfm;
}

struct mcryptd_cpu_queue {
	struct crypto_queue queue;
	struct work_struct work;
};

struct mcryptd_queue {
	struct mcryptd_cpu_queue __percpu *cpu_queue;
};

struct mcryptd_instance_ctx {
	struct crypto_spawn spawn;
	struct mcryptd_queue *queue;
};

struct mcryptd_hash_ctx {
	struct crypto_ahash *child;
	struct mcryptd_alg_state *alg_state;
};

struct mcryptd_tag {
	/* seq number of request */
	unsigned seq_num;
	/* arrival time of request */
	unsigned long arrival;
	unsigned long expire;
	int	cpu;
};

struct mcryptd_hash_request_ctx {
	struct list_head waiter;
	crypto_completion_t complete;
	struct mcryptd_tag tag;
	struct crypto_hash_walk walk;
	u8 *out;
	int flag;
	struct ahash_request areq;
};

struct mcryptd_ahash *mcryptd_alloc_ahash(const char *alg_name,
					u32 type, u32 mask);
struct crypto_ahash *mcryptd_ahash_child(struct mcryptd_ahash *tfm);
struct ahash_request *mcryptd_ahash_desc(struct ahash_request *req);
void mcryptd_free_ahash(struct mcryptd_ahash *tfm);
void mcryptd_flusher(struct work_struct *work);

enum mcryptd_req_type {
	MCRYPTD_NONE,
	MCRYPTD_UPDATE,
	MCRYPTD_FINUP,
	MCRYPTD_DIGEST,
	MCRYPTD_FINAL
};

struct mcryptd_alg_cstate {
	unsigned long next_flush;
	unsigned next_seq_num;
	bool	flusher_engaged;
	struct  delayed_work flush;
	int	cpu;
	struct  mcryptd_alg_state *alg_state;
	void	*mgr;
	spinlock_t work_lock;
	struct list_head work_list;
	struct list_head flush_list;
};

struct mcryptd_alg_state {
	struct mcryptd_alg_cstate __percpu *alg_cstate;
	unsigned long (*flusher)(struct mcryptd_alg_cstate *cstate);
};

/* return delay in jiffies from current time */
static inline unsigned long get_delay(unsigned long t)
{
	long delay;

	delay = (long) t - (long) jiffies;
	if (delay <= 0)
		return 0;
	else
		return (unsigned long) delay;
}

void mcryptd_arm_flusher(struct mcryptd_alg_cstate *cstate, unsigned long delay);

#endif
mmitter</option>
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<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>net</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/rds?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>rds</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='39cb2c9a316e77f6dfba96c543e55b6672d5a37e'/><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>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-29 13:50:06 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-29 13:50:06 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/rds?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>39cb2c9a316e77f6dfba96c543e55b6672d5a37e</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/rds?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>98fe974ee4e20121253de7f61fc8d01bdb3821c1</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/rds?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>net/rds</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/rds?id=2c5d9555d6d937966d79d4c6529a5f7b9206e405'>2c5d9555d6d937966d79d4c6529a5f7b9206e405</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/rds?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e&amp;id2=2c5d9555d6d937966d79d4c6529a5f7b9206e405'>diff</a>)</td></tr></table>
<div class='commit-subject'>drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()</div><div class='commit-msg'>I've seen this trigger twice now, where the i915_gem_object_to_ggtt()
call in intel_unpin_fb_obj() returns NULL, resulting in an oops
immediately afterwards as the (inlined) call to i915_vma_unpin_fence()
tries to dereference it.

It seems to be some race condition where the object is going away at
shutdown time, since both times happened when shutting down the X
server.  The call chains were different:

 - VT ioctl(KDSETMODE, KD_TEXT):

    intel_cleanup_plane_fb+0x5b/0xa0 [i915]
    drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper]
    intel_atomic_commit_tail+0x749/0xfe0 [i915]
    intel_atomic_commit+0x3cb/0x4f0 [i915]
    drm_atomic_commit+0x4b/0x50 [drm]
    restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper]
    drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper]
    drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper]
    intel_fbdev_set_par+0x18/0x70 [i915]
    fb_set_var+0x236/0x460
    fbcon_blank+0x30f/0x350
    do_unblank_screen+0xd2/0x1a0
    vt_ioctl+0x507/0x12a0
    tty_ioctl+0x355/0xc30
    do_vfs_ioctl+0xa3/0x5e0
    SyS_ioctl+0x79/0x90
    entry_SYSCALL_64_fastpath+0x13/0x94

 - i915 unpin_work workqueue:

    intel_unpin_work_fn+0x58/0x140 [i915]
    process_one_work+0x1f1/0x480
    worker_thread+0x48/0x4d0
    kthread+0x101/0x140

and this patch purely papers over the issue by adding a NULL pointer
check and a WARN_ON_ONCE() to avoid the oops that would then generally
make the machine unresponsive.

Other callers of i915_gem_object_to_ggtt() seem to also check for the
returned pointer being NULL and warn about it, so this clearly has
happened before in other places.

[ Reported it originally to the i915 developers on Jan 8, applying the
  ugly workaround on my own now after triggering the problem for the
  second time with no feedback.

  This is likely to be the same bug reported as

     https://bugs.freedesktop.org/show_bug.cgi?id=98829
     https://bugs.freedesktop.org/show_bug.cgi?id=99134

  which has a patch for the underlying problem, but it hasn't gotten to
  me, so I'm applying the workaround. ]

Cc: Daniel Vetter &lt;daniel.vetter@intel.com&gt;
Cc: Jani Nikula &lt;jani.nikula@linux.intel.com&gt;
Cc: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Cc: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Tvrtko Ursulin &lt;tvrtko.ursulin@intel.com&gt;
Cc: Imre Deak &lt;imre.deak@intel.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>Diffstat</a> (limited to 'net/rds')</div><table summary='diffstat' class='diffstat'>