linux-kernel - [PATCH 4.8 27/96] drm/nouveau/ttm: wait for bo fence to signal before unmapping vmas

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20170106214228.806764840@linuxfoundation.org>
Date:   Fri,  6 Jan 2017 22:43:15 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Ben Skeggs <bskeggs@...hat.com>
Subject: [PATCH 4.8 27/96] drm/nouveau/ttm: wait for bo fence to signal before unmapping vmas

4.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ben Skeggs <bskeggs@...hat.com>

commit 10dcab3e7f477bffee88d518aad57d06777cfdf4 upstream.

TTM was changed a while back to allow for pipelining of buffer moves, and
part of this was the removal of waiting for a BO to idle before calling
move(), placing the responsibility on the driver to do this if required.

That's all well and good, except, we make use of move_notify() to handle
mapping/unmapping from the GPU VMM as move() isn't called on all paths.

This commit adds a wait before unmapping from a VMM in move_notify(), to
prevent GPU page faults where a buffer is still being accessed.

Signed-off-by: Ben Skeggs <bskeggs@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/gpu/drm/nouveau/nouveau_bo.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -1209,6 +1209,7 @@ nouveau_bo_move_ntfy(struct ttm_buffer_o
 			       nvbo->page_shift != vma->vm->mmu->lpg_shift)) {
 			nvkm_vm_map(vma, new_mem->mm_node);
 		} else {
+			WARN_ON(ttm_bo_wait(bo, false, false));
 			nvkm_vm_unmap(vma);
 		}
 	}