From: Daniel Vetter <daniel.vetter@ffwll.ch>
To: DRI Development <dri-devel@lists.freedesktop.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>,
Intel Graphics Development <intel-gfx@lists.freedesktop.org>,
Daniel Vetter <daniel.vetter@intel.com>
Subject: [PATCH] drm/atomic: Fix double kfree on crtc_state->event
Date: Mon, 30 Jan 2017 18:53:39 +0100 [thread overview]
Message-ID: <20170130175339.10436-1-daniel.vetter@ffwll.ch> (raw)
This is a bug Maarten reported, with the following slab debug backtrace:
[IGT] kms_rotation_crc: starting subtest primary-rotation-180
=============================================================================
BUG kmalloc-128 (Tainted: G U ): Object already free
-----------------------------------------------------------------------------
Disabling lock debugging due to kernel taint
INFO: Allocated in drm_atomic_helper_setup_commit+0x285/0x2f0 [drm_kms_helper] age=0 cpu=3 pid=1529
___slab_alloc+0x308/0x3b0
__slab_alloc+0xd/0x20
kmem_cache_alloc_trace+0x92/0x1c0
drm_atomic_helper_setup_commit+0x285/0x2f0 [drm_kms_helper]
intel_atomic_commit+0x35/0x4f0 [i915]
drm_atomic_commit+0x46/0x50 [drm]
drm_mode_atomic_ioctl+0x7d4/0xab0 [drm]
drm_ioctl+0x2b3/0x490 [drm]
do_vfs_ioctl+0x69c/0x700
SyS_ioctl+0x4e/0x80
entry_SYSCALL_64_fastpath+0x13/0x94
INFO: Freed in drm_event_cancel_free+0xa3/0xb0 [drm] age=0 cpu=3 pid=1529
__slab_free+0x48/0x2e0
kfree+0x159/0x1a0
drm_event_cancel_free+0xa3/0xb0 [drm]
drm_mode_atomic_ioctl+0x86d/0xab0 [drm]
drm_ioctl+0x2b3/0x490 [drm]
do_vfs_ioctl+0x69c/0x700
SyS_ioctl+0x4e/0x80
entry_SYSCALL_64_fastpath+0x13/0x94
INFO: Slab 0xffffde1f0997b080 objects=17 used=2 fp=0xffff92fb65ec2578 flags=0x200000000008101
INFO: Object 0xffff92fb65ec2578 @offset=1400 fp=0xffff92fb65ec2ae8
Redzone ffff92fb65ec2570: bb bb bb bb bb bb bb bb ........
Object ffff92fb65ec2578: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object ffff92fb65ec2588: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object ffff92fb65ec2598: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object ffff92fb65ec25a8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object ffff92fb65ec25b8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object ffff92fb65ec25c8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object ffff92fb65ec25d8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object ffff92fb65ec25e8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 kkkkkkkkkkkkkkk.
Redzone ffff92fb65ec25f8: bb bb bb bb bb bb bb bb ........
Padding ffff92fb65ec2738: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ
CPU: 3 PID: 180 Comm: kworker/3:2 Tainted: G BU 4.10.0-rc6-patser+ #5039
Hardware name: /NUC5PPYB, BIOS PYBSWCEL.86A.0031.2015.0601.1712 06/01/2015
Workqueue: events intel_atomic_helper_free_state [i915]
Call Trace:
dump_stack+0x4d/0x6d
print_trailer+0x20c/0x220
free_debug_processing+0x1c6/0x330
? drm_atomic_state_default_clear+0xf7/0x1c0 [drm]
__slab_free+0x48/0x2e0
? drm_atomic_state_default_clear+0xf7/0x1c0 [drm]
kfree+0x159/0x1a0
drm_atomic_state_default_clear+0xf7/0x1c0 [drm]
? drm_atomic_state_clear+0x30/0x30 [drm]
intel_atomic_state_clear+0xd/0x20 [i915]
drm_atomic_state_clear+0x1a/0x30 [drm]
__drm_atomic_state_free+0x13/0x60 [drm]
intel_atomic_helper_free_state+0x5d/0x70 [i915]
process_one_work+0x260/0x4a0
worker_thread+0x2d1/0x4f0
kthread+0x127/0x130
? process_one_work+0x4a0/0x4a0
? kthread_stop+0x120/0x120
ret_from_fork+0x29/0x40
FIX kmalloc-128: Object at 0xffff92fb65ec2578 not freed
Reported-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
---
drivers/gpu/drm/drm_atomic.c | 24 ++++++++++++++++++++----
1 file changed, 20 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 026be94a7d15..366b4bf88206 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -159,15 +159,29 @@ void drm_atomic_state_default_clear(struct drm_atomic_state *state)
if (!crtc)
continue;
- crtc->funcs->atomic_destroy_state(crtc,
- state->crtcs[i].state);
-
if (state->crtcs[i].commit) {
- kfree(state->crtcs[i].commit->event);
+ /*
+ * We need to make sure we don't double-free, which we
+ * do by checking for state->event, implicitly since
+ * kfree can handle a NULL state->event. We also need to
+ * make sure we only kfree the event if it's one created
+ * for internal commit tracking (and hence won't be
+ * cleared by the caller, like the atomic IOCTL or a
+ * legacy pageflip. This is done by checking
+ * commit->event.
+ *
+ * This only works if everyone else sets state->event to
+ * NULL when they take it away.
+ */
+ if (state->crtcs[i].commit->event)
+ kfree(state->crtcs[i].commit->event);
state->crtcs[i].commit->event = NULL;
drm_crtc_commit_put(state->crtcs[i].commit);
}
+ crtc->funcs->atomic_destroy_state(crtc,
+ state->crtcs[i].state);
+
state->crtcs[i].commit = NULL;
state->crtcs[i].ptr = NULL;
state->crtcs[i].state = NULL;
@@ -2034,6 +2048,8 @@ static void complete_crtc_signaling(struct drm_device *dev,
*/
if (crtc_state->event)
drm_event_cancel_free(dev, &crtc_state->event->base);
+
+ crtc_state->event = NULL;
}
if (!fence_state)
--
2.11.0
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
next reply other threads:[~2017-01-30 17:53 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-30 17:53 Daniel Vetter [this message]
2017-01-30 22:54 ` ✓ Fi.CI.BAT: success for drm/atomic: Fix double kfree on crtc_state->event Patchwork
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170130175339.10436-1-daniel.vetter@ffwll.ch \
--to=daniel.vetter@ffwll.ch \
--cc=daniel.vetter@intel.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=intel-gfx@lists.freedesktop.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.