Attachment 59443 Details for Bug 48105 – Detect writes to address 0

[patch] Detect writes to address 0

0001-agp-intel-drm-i915-Catch-address-0-writes-using-inva.patch (text/plain), 2.29 KB, created by Chris Wilson on 2012-04-03 11:14:33 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Chris Wilson

Created: 2012-04-03 11:14:33 UTC

Size: 2.29 KB

patch

obsolete

>From 4a2fee8527f8b15195f27b7936658a6f737e93d9 Mon Sep 17 00:00:00 2001
>From: Chris Wilson <chris@chris-wilson.co.uk>
>Date: Tue, 3 Apr 2012 14:46:12 +0100
>Subject: [PATCH] agp/intel,drm/i915: Catch address-0 writes using invalid
> PTEs
>
>Beware the evil userspace that likes to overwrite the HWS and
>ringbuffers by using the GPU to detect wild writes to address 0.
>---
> drivers/char/agp/intel-gtt.c        |   11 +++++++++++
> drivers/gpu/drm/i915/i915_gem_gtt.c |    3 +++
> include/drm/intel-gtt.h             |    1 +
> 3 files changed, 15 insertions(+), 0 deletions(-)
>
>diff --git a/drivers/char/agp/intel-gtt.c b/drivers/char/agp/intel-gtt.c
>index 7e223a2..9291cde 100644
>--- a/drivers/char/agp/intel-gtt.c
>+++ b/drivers/char/agp/intel-gtt.c
>@@ -970,6 +970,17 @@ out_err:
> 	return ret;
> }
> 
>+void intel_gtt_zap_range(unsigned int first_entry, unsigned int num_entries)
>+{
>+	unsigned int i;
>+
>+	for (i = first_entry; i < (first_entry + num_entries); i++) {
>+		writel(0, intel_private.gtt + i);
>+	}
>+	readl(intel_private.gtt+i-1);
>+}
>+EXPORT_SYMBOL(intel_gtt_zap_range);
>+
> void intel_gtt_clear_range(unsigned int first_entry, unsigned int num_entries)
> {
> 	unsigned int i;
>diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
>index 5a626f7..f3afc7b 100644
>--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
>+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
>@@ -429,6 +429,9 @@ void i915_gem_init_global_gtt(struct drm_device *dev,
> {
> 	drm_i915_private_t *dev_priv = dev->dev_private;
> 
>+	intel_gtt_zap_range(start / PAGE_SIZE, 16);
>+	start += 16 * PAGE_SIZE;
>+
> 	/* Substract the guard page ... */
> 	drm_mm_init(&dev_priv->mm.gtt_space, start, end - start - PAGE_SIZE);
> 
>diff --git a/include/drm/intel-gtt.h b/include/drm/intel-gtt.h
>index 0a0001b..5feb7d8 100644
>--- a/include/drm/intel-gtt.h
>+++ b/include/drm/intel-gtt.h
>@@ -24,6 +24,7 @@ const struct intel_gtt {
> void intel_gtt_chipset_flush(void);
> void intel_gtt_unmap_memory(struct scatterlist *sg_list, int num_sg);
> void intel_gtt_clear_range(unsigned int first_entry, unsigned int num_entries);
>+void intel_gtt_zap_range(unsigned int first_entry, unsigned int num_entries);
> int intel_gtt_map_memory(struct page **pages, unsigned int num_entries,
> 			 struct scatterlist **sg_list, int *num_sg);
> void intel_gtt_insert_sg_entries(struct scatterlist *sg_list,
>-- 
>1.7.9.1
>

Actions: View | Splinter Review

Attachments on bug 48105: 59295 | 59296 | 59297 | 59298 | 59324 | 59325 | 59407 | 59421 | 59443

Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.