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authorChris Wilson <chris@chris-wilson.co.uk>2020-07-30 10:28:56 +0100
committerJani Nikula <jani.nikula@intel.com>2020-09-16 11:09:20 +0300
commite7d95527f27a6d9edcffbd74eee38e5cb6b91785 (patch)
tree8ccaeafbcdfdb3ab1729bfc7a553a4c0181efd11 /drivers/gpu
parent856deb866d16e29bd65952e0289066f6078af773 (diff)
drm/i915/gem: Delay tracking the GEM context until it is registered
Avoid exposing a partially constructed context by deferring the list_add() from the initial construction to the end of registration. Otherwise, if we peek into the list of contexts from inside debugfs, we may see the partially constructed context and chase down some dangling incomplete pointers. Reported-by: CQ Tang <cq.tang@intel.com> Fixes: 3aa9945a528e ("drm/i915: Separate GEM context construction and registration to userspace") References: f6e8aa387171 ("drm/i915: Report the number of closed vma held by each context in debugfs") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: CQ Tang <cq.tang@intel.com> Cc: <stable@vger.kernel.org> # v5.2+ Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200730092856.23615-1-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> (cherry picked from commit eb4dedae920a07c485328af3da2202ec5184fb17) Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Diffstat (limited to 'drivers/gpu')
-rw-r--r--drivers/gpu/drm/i915/gem/i915_gem_context.c16
1 files changed, 11 insertions, 5 deletions
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index d0bdb6d447ed..efc4ba34c06e 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -713,6 +713,7 @@ __create_context(struct drm_i915_private *i915)
ctx->i915 = i915;
ctx->sched.priority = I915_USER_PRIORITY(I915_PRIORITY_NORMAL);
mutex_init(&ctx->mutex);
+ INIT_LIST_HEAD(&ctx->link);
spin_lock_init(&ctx->stale.lock);
INIT_LIST_HEAD(&ctx->stale.engines);
@@ -740,10 +741,6 @@ __create_context(struct drm_i915_private *i915)
for (i = 0; i < ARRAY_SIZE(ctx->hang_timestamp); i++)
ctx->hang_timestamp[i] = jiffies - CONTEXT_FAST_HANG_JIFFIES;
- spin_lock(&i915->gem.contexts.lock);
- list_add_tail(&ctx->link, &i915->gem.contexts.list);
- spin_unlock(&i915->gem.contexts.lock);
-
return ctx;
err_free:
@@ -931,6 +928,7 @@ static int gem_context_register(struct i915_gem_context *ctx,
struct drm_i915_file_private *fpriv,
u32 *id)
{
+ struct drm_i915_private *i915 = ctx->i915;
struct i915_address_space *vm;
int ret;
@@ -949,8 +947,16 @@ static int gem_context_register(struct i915_gem_context *ctx,
/* And finally expose ourselves to userspace via the idr */
ret = xa_alloc(&fpriv->context_xa, id, ctx, xa_limit_32b, GFP_KERNEL);
if (ret)
- put_pid(fetch_and_zero(&ctx->pid));
+ goto err_pid;
+
+ spin_lock(&i915->gem.contexts.lock);
+ list_add_tail(&ctx->link, &i915->gem.contexts.list);
+ spin_unlock(&i915->gem.contexts.lock);
+
+ return 0;
+err_pid:
+ put_pid(fetch_and_zero(&ctx->pid));
return ret;
}