[PATCH v10 21/27] scripts: add `is_rust_module.sh`

[Miguel Ojeda]

From: Daniel Xu <dxu@xxxxxxxxx>

This script is used to detect whether a kernel module is written
in Rust.

It will later be used to disable BTF generation on Rust modules as
BTF does not yet support Rust.

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Co-developed-by: Alex Gaynor <alex.gaynor@xxxxxxxxx>
Signed-off-by: Alex Gaynor <alex.gaynor@xxxxxxxxx>
Co-developed-by: Wedson Almeida Filho <wedsonaf@xxxxxxxxxx>
Signed-off-by: Wedson Almeida Filho <wedsonaf@xxxxxxxxxx>
Signed-off-by: Daniel Xu <dxu@xxxxxxxxx>
Co-developed-by: Miguel Ojeda <ojeda@xxxxxxxxxx>
Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx>
---
 scripts/is_rust_module.sh | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100755 scripts/is_rust_module.sh

diff --git a/scripts/is_rust_module.sh b/scripts/is_rust_module.sh
new file mode 100755
index 000000000000..28b3831a7593
--- /dev/null
+++ b/scripts/is_rust_module.sh
@@ -0,0 +1,16 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# is_rust_module.sh module.ko
+#
+# Returns `0` if `module.ko` is a Rust module, `1` otherwise.
+
+set -e
+
+# Using the `16_` prefix ensures other symbols with the same substring
+# are not picked up (even if it would be unlikely). The last part is
+# used just in case LLVM decides to use the `.` suffix.
+#
+# In the future, checking for the `.comment` section may be another
+# option, see https://github.com/rust-lang/rust/pull/97550.
+${NM} "$*" | grep -qE '^[0-9a-fA-F]+ r _R[^[:space:]]+16___IS_RUST_MODULE[^[:space:]]*$'
-- 
2.37.3