From 1d0e2c9359fec6212af8c5fb29d5d56269f96968 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 2 Jan 2020 13:17:07 +0000 Subject: [PATCH] drm/i915/gt: Always poison the kernel_context image before unparking Keep scrubbing the kernel_context image with poison before we reset it in order to demonstrate that we will be resilient in the case where it is accidentally overwritten on idle. Suggested-by: Imre Deak Signed-off-by: Chris Wilson Cc: Imre Deak Reviewed-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/20200102131707.1463945-5-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/gt/intel_context_types.h | 2 ++ drivers/gpu/drm/i915/gt/intel_engine_pm.c | 18 +++++++++++++++++- drivers/gpu/drm/i915/gt/intel_lrc.c | 4 ++-- 3 files changed, 21 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h index 9527a659546c..ca1420fb8b53 100644 --- a/drivers/gpu/drm/i915/gt/intel_context_types.h +++ b/drivers/gpu/drm/i915/gt/intel_context_types.h @@ -17,6 +17,8 @@ #include "intel_engine_types.h" #include "intel_sseu.h" +#define CONTEXT_REDZONE POISON_INUSE + struct i915_gem_context; struct i915_vma; struct intel_context; diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pm.c b/drivers/gpu/drm/i915/gt/intel_engine_pm.c index 1b9f73948f22..ea90ab3e396e 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_pm.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_pm.c @@ -37,8 +37,24 @@ static int __engine_unpark(struct intel_wakeref *wf) /* Discard stale context state from across idling */ ce = engine->kernel_context; - if (ce) + if (ce) { + GEM_BUG_ON(test_bit(CONTEXT_VALID_BIT, &ce->flags)); + + /* First poison the image to verify we never fully trust it */ + if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM) && ce->state) { + struct drm_i915_gem_object *obj = ce->state->obj; + int type = i915_coherent_map_type(engine->i915); + + map = i915_gem_object_pin_map(obj, type); + if (!IS_ERR(map)) { + memset(map, CONTEXT_REDZONE, obj->base.size); + i915_gem_object_flush_map(obj); + i915_gem_object_unpin_map(obj); + } + } + ce->ops->reset(ce); + } if (engine->unpark) engine->unpark(engine); diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index b21a191bda3b..170b5a0139a3 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -2507,7 +2507,7 @@ set_redzone(void *vaddr, const struct intel_engine_cs *engine) vaddr += engine->context_size; - memset(vaddr, POISON_INUSE, I915_GTT_PAGE_SIZE); + memset(vaddr, CONTEXT_REDZONE, I915_GTT_PAGE_SIZE); } static void @@ -2518,7 +2518,7 @@ check_redzone(const void *vaddr, const struct intel_engine_cs *engine) vaddr += engine->context_size; - if (memchr_inv(vaddr, POISON_INUSE, I915_GTT_PAGE_SIZE)) + if (memchr_inv(vaddr, CONTEXT_REDZONE, I915_GTT_PAGE_SIZE)) dev_err_once(engine->i915->drm.dev, "%s context redzone overwritten!\n", engine->name); -- 2.11.0