[3.8.y.z extended stable] Patch "drm/ttm: don't oops if no invalidate_caches()" has been added to staging queue

Kamal Mostafa kamal at canonical.com
Mon Mar 31 17:20:40 UTC 2014


This is a note to let you know that I have just added a patch titled

    drm/ttm: don't oops if no invalidate_caches()

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.21.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 7ec3f13e98bdd58970680dbf807a3cc9626246c1 Mon Sep 17 00:00:00 2001
From: Rob Clark <rclark at redhat.com>
Date: Wed, 12 Mar 2014 10:59:37 -0400
Subject: drm/ttm: don't oops if no invalidate_caches()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

commit 9ef7506f7eff3fc42724269f62e30164c141661f upstream.

A few of the simpler TTM drivers (cirrus, ast, mgag200) do not implement
this function.  Yet can end up somehow with an evicted bo:

  BUG: unable to handle kernel NULL pointer dereference at           (null)
  IP: [<          (null)>]           (null)
  PGD 16e761067 PUD 16e6cf067 PMD 0
  Oops: 0010 [#1] SMP
  Modules linked in: bnep bluetooth rfkill fuse ip6t_rpfilter ip6t_REJECT ipt_REJECT xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw iptable_filter ip_tables sg btrfs zlib_deflate raid6_pq xor dm_queue_length iTCO_wdt iTCO_vendor_support coretemp kvm dcdbas dm_service_time microcode serio_raw pcspkr lpc_ich mfd_core i7core_edac edac_core ses enclosure ipmi_si ipmi_msghandler shpchp acpi_power_meter mperf nfsd auth_rpcgss nfs_acl lockd uinput sunrpc dm_multipath xfs libcrc32c ata_generic pata_acpi sr_mod cdrom
   sd_mod usb_storage mgag200 syscopyarea sysfillrect sysimgblt i2c_algo_bit lpfc drm_kms_helper ttm crc32c_intel ata_piix bfa drm ixgbe libata i2c_core mdio crc_t10dif ptp crct10dif_common pps_core scsi_transport_fc dca scsi_tgt megaraid_sas bnx2 dm_mirror dm_region_hash dm_log dm_mod
  CPU: 16 PID: 2572 Comm: X Not tainted 3.10.0-86.el7.x86_64 #1
  Hardware name: Dell Inc. PowerEdge R810/0H235N, BIOS 0.3.0 11/14/2009
  task: ffff8801799dabc0 ti: ffff88016c884000 task.ti: ffff88016c884000
  RIP: 0010:[<0000000000000000>]  [<          (null)>]           (null)
  RSP: 0018:ffff88016c885ad8  EFLAGS: 00010202
  RAX: ffffffffa04e94c0 RBX: ffff880178937a20 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: 0000000000240004 RDI: ffff880178937a00
  RBP: ffff88016c885b60 R08: 00000000000171a0 R09: ffff88007cf171a0
  R10: ffffea0005842540 R11: ffffffff810487b9 R12: ffff880178937b30
  R13: ffff880178937a00 R14: ffff88016c885b78 R15: ffff880179929400
  FS:  00007f81ba2ef980(0000) GS:ffff88007cf00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000000 CR3: 000000016e763000 CR4: 00000000000007e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  Stack:
   ffffffffa0306fae ffff8801799295c0 0000000000260004 0000000000000001
   ffff88016c885b60 ffffffffa0307669 00ff88007cf17738 ffff88017cf17700
   ffff880178937a00 ffff880100000000 ffff880100000000 0000000079929400
  Call Trace:
   [<ffffffffa0306fae>] ? ttm_bo_handle_move_mem+0x54e/0x5b0 [ttm]
   [<ffffffffa0307669>] ? ttm_bo_mem_space+0x169/0x340 [ttm]
   [<ffffffffa0307bd7>] ttm_bo_move_buffer+0x117/0x130 [ttm]
   [<ffffffff81130001>] ? perf_event_init_context+0x141/0x220
   [<ffffffffa0307cb1>] ttm_bo_validate+0xc1/0x130 [ttm]
   [<ffffffffa04e7377>] mgag200_bo_pin+0x87/0xc0 [mgag200]
   [<ffffffffa04e56c4>] mga_crtc_cursor_set+0x474/0xbb0 [mgag200]
   [<ffffffff811971d2>] ? __mem_cgroup_commit_charge+0x152/0x3b0
   [<ffffffff815c4182>] ? mutex_lock+0x12/0x2f
   [<ffffffffa0201433>] drm_mode_cursor_common+0x123/0x170 [drm]
   [<ffffffffa0205231>] drm_mode_cursor_ioctl+0x41/0x50 [drm]
   [<ffffffffa01f5ca2>] drm_ioctl+0x502/0x630 [drm]
   [<ffffffff815cbab4>] ? __do_page_fault+0x1f4/0x510
   [<ffffffff8101cb68>] ? __restore_xstate_sig+0x218/0x4f0
   [<ffffffff811b4445>] do_vfs_ioctl+0x2e5/0x4d0
   [<ffffffff8124488e>] ? file_has_perm+0x8e/0xa0
   [<ffffffff811b46b1>] SyS_ioctl+0x81/0xa0
   [<ffffffff815d05d9>] system_call_fastpath+0x16/0x1b
  Code:  Bad RIP value.
  RIP  [<          (null)>]           (null)
   RSP <ffff88016c885ad8>
  CR2: 0000000000000000

Signed-off-by: Rob Clark <rclark at redhat.com>
Reviewed-by: Jérôme Glisse <jglisse at redhat.com>
Reviewed-by: Thomas Hellstrom <thellstrom at vmware.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/gpu/drm/ttm/ttm_bo.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index ba60a89..5b94cde 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -442,9 +442,11 @@ static int ttm_bo_handle_move_mem(struct ttm_buffer_object *bo,

 moved:
 	if (bo->evicted) {
-		ret = bdev->driver->invalidate_caches(bdev, bo->mem.placement);
-		if (ret)
-			pr_err("Can not flush read caches\n");
+		if (bdev->driver->invalidate_caches) {
+			ret = bdev->driver->invalidate_caches(bdev, bo->mem.placement);
+			if (ret)
+				pr_err("Can not flush read caches\n");
+		}
 		bo->evicted = false;
 	}

--
1.8.3.2





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