From: Tom St Denis <tom.stdenis@amd.com>
Date: Tue, 23 May 2017 15:35:22 +0000 (-0400)
Subject: drm/amd/amdgpu: Return error if initiating read out of range on vram
X-Git-Tag: v4.4.79~39
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ad2efae4613d2090ec7a5654429bf3ff08ea309b;p=thirdparty%2Fkernel%2Fstable.git

drm/amd/amdgpu: Return error if initiating read out of range on vram

commit 9156e723301c0a7a7def4cde820e018ce791b842 upstream.

If you initiate a read that is out of the VRAM address space return
ENXIO instead of 0.

Reads that begin below that point will read upto the VRAM limit as
before.

Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 475c38fe92453..e40a6d8b0b928 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1126,6 +1126,9 @@ static ssize_t amdgpu_ttm_vram_read(struct file *f, char __user *buf,
 	if (size & 0x3 || *pos & 0x3)
 		return -EINVAL;
 
+	if (*pos >= adev->mc.mc_vram_size)
+		return -ENXIO;
+
 	while (size) {
 		unsigned long flags;
 		uint32_t value;