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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2020-07-23 18:21:19 +0100 |
|---|---|---|
| committer | Rodrigo Vivi <rodrigo.vivi@intel.com> | 2020-09-30 14:24:37 -0400 |
| commit | 4fe9af8e881d946bf60790eeb37a7c4f96e28382 (patch) | |
| tree | 138f5cc7f7c3beddd27bd283a778205a49001f50 | |
| parent | cef8ce5528bf61a91d3116f327fc6b78310facfa (diff) | |
| download | linux-4fe9af8e881d946bf60790eeb37a7c4f96e28382.tar.bz2 | |
drm/i915/gem: Serialise debugfs i915_gem_objects with ctx->mutex
Since the debugfs may peek into the GEM contexts as the corresponding
client/fd is being closed, we may try and follow a dangling pointer.
However, the context closure itself is serialised with the ctx->mutex,
so if we hold that mutex as we inspect the state coupled in the context,
we know the pointers within the context are stable and will remain valid
as we inspect their tables.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: CQ Tang <cq.tang@intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200723172119.17649-3-chris@chris-wilson.co.uk
(cherry picked from commit 102f5aa491f262c818e607fc4fee08a724a76c69)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
| -rw-r--r-- | drivers/gpu/drm/i915/i915_debugfs.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index 784219962193..ea469168cd44 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -326,6 +326,7 @@ static void print_context_stats(struct seq_file *m, } i915_gem_context_unlock_engines(ctx); + mutex_lock(&ctx->mutex); if (!IS_ERR_OR_NULL(ctx->file_priv)) { struct file_stats stats = { .vm = rcu_access_pointer(ctx->vm), @@ -346,6 +347,7 @@ static void print_context_stats(struct seq_file *m, print_file_stats(m, name, stats); } + mutex_unlock(&ctx->mutex); spin_lock(&i915->gem.contexts.lock); list_safe_reset_next(ctx, cn, link); |