selftests/bpf: Check that JMP32 pointer vs zero jumps are not predictedgrafted

Add jmp32_ptr_vs_zero_jne: the fall-through of the 32-bit compare, which
the verifier used to skip, contains an out of bounds map value access,
hence w/o the previous patch the program is accepted. See previous patch
for detailed description.

Reported-by: Nicholas Carlini <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260904083325.2083493-6-eddyz87@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

1 files changed, 112 insertions, 0 deletions

diff --git a/rust/quote/ext.rs b/rust/quote/ext.rs
new file mode 100644
index 000000000..977d2f0c5
--- /dev/null
+++ b/rust/quote/ext.rs
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+use super::ToTokens;
+use core::iter;
+use proc_macro2::{TokenStream, TokenTree};
+
+/// TokenStream extension trait with methods for appending tokens.
+///
+/// This trait is sealed and cannot be implemented outside of the `quote` crate.
+pub trait TokenStreamExt: private::Sealed {
+    /// For use by `ToTokens` implementations.
+    ///
+    /// Appends the token specified to this list of tokens.
+    fn append<U>(&mut self, token: U)
+    where
+        U: Into<TokenTree>;
+
+    /// For use by `ToTokens` implementations.
+    ///
+    /// ```
+    /// # use quote::{quote, TokenStreamExt, ToTokens};
+    /// # use proc_macro2::TokenStream;
+    /// #
+    /// struct X;
+    ///
+    /// impl ToTokens for X {
+    ///     fn to_tokens(&self, tokens: &mut TokenStream) {
+    ///         tokens.append_all(&[true, false]);
+    ///     }
+    /// }
+    ///
+    /// let tokens = quote!(#X);
+    /// assert_eq!(tokens.to_string(), "true false");
+    /// ```
+    fn append_all<I>(&mut self, iter: I)
+    where
+        I: IntoIterator,
+        I::Item: ToTokens;
+
+    /// For use by `ToTokens` implementations.
+    ///
+    /// Appends all of the items in the iterator `I`, separated by the tokens
+    /// `U`.
+    fn append_separated<I, U>(&mut self, iter: I, op: U)
+    where
+        I: IntoIterator,
+        I::Item: ToTokens,
+        U: ToTokens;
+
+    /// For use by `ToTokens` implementations.
+    ///
+    /// Appends all tokens in the iterator `I`, appending `U` after each
+    /// element, including after the last element of the iterator.
+    fn append_terminated<I, U>(&mut self, iter: I, term: U)
+    where
+        I: IntoIterator,
+        I::Item: ToTokens,
+        U: ToTokens;
+}
+
+impl TokenStreamExt for TokenStream {
+    fn append<U>(&mut self, token: U)
+    where
+        U: Into<TokenTree>,
+    {
+        self.extend(iter::once(token.into()));
+    }
+
+    fn append_all<I>(&mut self, iter: I)
+    where
+        I: IntoIterator,
+        I::Item: ToTokens,
+    {
+        for token in iter {
+            token.to_tokens(self);
+        }
+    }
+
+    fn append_separated<I, U>(&mut self, iter: I, op: U)
+    where
+        I: IntoIterator,
+        I::Item: ToTokens,
+        U: ToTokens,
+    {
+        for (i, token) in iter.into_iter().enumerate() {
+            if i > 0 {
+                op.to_tokens(self);
+            }
+            token.to_tokens(self);
+        }
+    }
+
+    fn append_terminated<I, U>(&mut self, iter: I, term: U)
+    where
+        I: IntoIterator,
+        I::Item: ToTokens,
+        U: ToTokens,
+    {
+        for token in iter {
+            token.to_tokens(self);
+            term.to_tokens(self);
+        }
+    }
+}
+
+mod private {
+    use proc_macro2::TokenStream;
+
+    pub trait Sealed {}
+
+    impl Sealed for TokenStream {}
+}