From f1ec934dbc58958b621a9212168e450ce9496c6d Mon Sep 17 00:00:00 2001
From: Erich Gubler <erichdongubler@gmail.com>
Date: Thu, 21 Nov 2024 09:49:20 -0500
Subject: [PATCH] fix(core): validate that begin and end indices of pass
 timestamp writes are not equal

---
 CHANGELOG.md                     | 1 +
 wgpu-core/src/command/compute.rs | 9 +++++++++
 wgpu-core/src/command/mod.rs     | 4 ++++
 wgpu-core/src/command/render.rs  | 8 ++++++++
 4 files changed, 22 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 00b81f6a50..ee63a2bde9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -134,6 +134,7 @@ By @ErichDonGubler in [#6456](https://github.com/gfx-rs/wgpu/pull/6456), [#6148]
 - Add missing validation for timestamp writes in compute and render passes. By @ErichDonGubler in [#6578](https://github.com/gfx-rs/wgpu/pull/6578).
   - Check the status of the `TIMESTAMP_QUERY` feature before other validation.
   - Check that indices are in-bounds for the query set.
+  - Check that begin and end indices are not equal.
 
 #### Naga
 
diff --git a/wgpu-core/src/command/compute.rs b/wgpu-core/src/command/compute.rs
index dc8c6055c5..f27ad1a8bb 100644
--- a/wgpu-core/src/command/compute.rs
+++ b/wgpu-core/src/command/compute.rs
@@ -345,6 +345,15 @@ impl Global {
                 }
             }
 
+            if let Some((begin, end)) = beginning_of_pass_write_index.zip(end_of_pass_write_index) {
+                if begin == end {
+                    return make_err(
+                        CommandEncoderError::TimestampWriteIndicesEqual { idx: begin },
+                        arc_desc,
+                    );
+                }
+            }
+
             Some(ArcPassTimestampWrites {
                 query_set,
                 beginning_of_pass_write_index,
diff --git a/wgpu-core/src/command/mod.rs b/wgpu-core/src/command/mod.rs
index 6c7b26b786..1f1cafaf5e 100644
--- a/wgpu-core/src/command/mod.rs
+++ b/wgpu-core/src/command/mod.rs
@@ -654,6 +654,10 @@ pub enum CommandEncoderError {
     InvalidResource(#[from] InvalidResourceError),
     #[error(transparent)]
     MissingFeatures(#[from] MissingFeatures),
+    #[error(
+        "begin and end indices of pass timestamp writes are both set to {idx}, which is not allowed"
+    )]
+    TimestampWriteIndicesEqual { idx: u32 },
     #[error(transparent)]
     TimestampWritesInvalid(#[from] QueryUseError),
 }
diff --git a/wgpu-core/src/command/render.rs b/wgpu-core/src/command/render.rs
index ffec953888..21c9a75f5b 100644
--- a/wgpu-core/src/command/render.rs
+++ b/wgpu-core/src/command/render.rs
@@ -1412,6 +1412,14 @@ impl Global {
                     query_set.validate_query(SimplifiedQueryType::Timestamp, idx, None)?;
                 }
 
+                if let Some((begin, end)) =
+                    beginning_of_pass_write_index.zip(end_of_pass_write_index)
+                {
+                    if begin == end {
+                        return Err(CommandEncoderError::TimestampWriteIndicesEqual { idx: begin });
+                    }
+                }
+
                 Some(ArcPassTimestampWrites {
                     query_set,
                     beginning_of_pass_write_index,