/* mpihelp-lshift.c - MPI helper functions
* Copyright (C) 1994, 1996, 1998, 2001 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG 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 of the License, or
* (at your option) any later version.
*
* GnuPG 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*
* Note: This code is heavily based on the GNU MP Library.
* Actually it's the same code with only minor changes in the
* way the data is stored; this is to support the abstraction
* of an optional secure memory allocation which may be used
* to avoid revealing of sensitive data due to paging etc.
* The GNU MP Library itself is published under the LGPL;
* however I decided to publish this code under the plain GPL.
*/
#include "mpi-internal.h"
/* Shift U (pointed to by UP and USIZE digits long) CNT bits to the left
* and store the USIZE least significant digits of the result at WP.
* Return the bits shifted out from the most significant digit.
*
* Argument constraints:
* 1. 0 < CNT < BITS_PER_MP_LIMB
* 2. If the result is to be written over the input, WP must be >= UP.
*/
mpi_limb_t
mpihelp_lshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize, unsigned int cnt)
{
mpi_limb_t high_limb, low_limb;
unsigned sh_1, sh_2;
mpi_size_t i;
mpi_limb_t retval;
sh_1 = cnt;
wp += 1;
sh_2 = BITS_PER_MPI_LIMB - sh_1;
i = usize - 1;
low_limb = up[i];
retval = low_limb >> sh_2;
high_limb = low_limb;
while (--i >= 0) {
low_limb = up[i];
wp[i] = (high_limb << sh_1) | (low_limb >> sh_2);
high_limb = low_limb;
}
wp[i] = high_limb << sh_1;
return retval;
}
ve&id=92c715fca907686f5298220ece53423e38ba3aed'>diff
drm/atomic: Fix double free in drm_atomic_state_default_clear
drm_atomic_helper_page_flip and drm_atomic_ioctl set their own events
in crtc_state->event. But when it's set the event is freed in 2 places.
Solve this by only freeing the event in the atomic ioctl when it
allocated its own event.
This has been broken twice. The first time when the code was introduced,
but only in the corner case when an event is allocated, but more crtc's
were included by atomic check and then failing. This can mostly
happen when you do an atomic modeset in i915 and the display clock is
changed, which forces all crtc's to be included to the state.
This has been broken worse by adding in-fences support, which caused
the double free to be done unconditionally.
[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
Fixes: 3b24f7d67581 ("drm/atomic: Add struct drm_crtc_commit to track async updates")
Fixes: 9626014258a5 ("drm/fence: add in-fences support")
Cc: <stable@vger.kernel.org> # v4.8+
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1485854725-27640-1-git-send-email-maarten.lankhorst@linux.intel.com