From d22c3e0088e85be8131f7a9283f759cdbb20726d Mon Sep 17 00:00:00 2001 From: Sven Schnelle Date: Wed, 9 Sep 2026 11:29:53 +0200 Subject: selftests/ftrace: Fix unique symbol check in kprobe_non_uniq_symbol.tc The current regex also matches symbols in modules, which makes the test fail on s390 where name_show is present only once in the kernel, but also multiple times in modules: 000001b1401cdc20 t name_show 000001b0c05e6c40 t name_show [mdev] 000001b0c0495f30 t name_show [i2c_core] Fix this by changing the regular expression to only match the function name. Link: https://lore.kernel.org/all/20260909092954.2200558-1-svens@linux.ibm.com/ Fixes: 03b80ff8023a ("selftests/ftrace: Add new test case which checks non unique symbol") Signed-off-by: Sven Schnelle Reviewed-by: Steven Rostedt Signed-off-by: Masami Hiramatsu (Google) --- Documentation/process/programming-language.rst | 58 ++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 Documentation/process/programming-language.rst (limited to 'Documentation/process/programming-language.rst') diff --git a/Documentation/process/programming-language.rst b/Documentation/process/programming-language.rst new file mode 100644 index 000000000..c18e307cc --- /dev/null +++ b/Documentation/process/programming-language.rst @@ -0,0 +1,58 @@ +.. _programming_language: + +Programming Language +==================== + +The Linux kernel is written in the C programming language [c-language]_. +More precisely, it is typically compiled with ``gcc`` [gcc]_ +under ``-std=gnu11`` [gcc-c-dialect-options]_: the GNU dialect of ISO C11. +``clang`` [clang]_ is also supported; see documentation on +:ref:`Building Linux with Clang/LLVM `. + +This dialect contains many extensions to the language [gnu-extensions]_, +and many of them are used within the kernel as a matter of course. + +Attributes +---------- + +One of the common extensions used throughout the kernel are attributes +[gcc-attribute-syntax]_. Attributes allow to introduce +implementation-defined semantics to language entities (like variables, +functions or types) without having to make significant syntactic changes +to the language (e.g. adding a new keyword) [n2049]_. + +In some cases, attributes are optional (i.e. a compiler not supporting them +should still produce proper code, even if it is slower or does not perform +as many compile-time checks/diagnostics). + +The kernel defines pseudo-keywords (e.g. ``__pure``) instead of using +directly the GNU attribute syntax (e.g. ``__attribute__((__pure__))``) +in order to feature detect which ones can be used and/or to shorten the code. + +Please refer to ``include/linux/compiler_attributes.h`` for more information. + +Rust +---- + +The kernel has support for the Rust programming language +[rust-language]_ under ``CONFIG_RUST``. It is compiled with ``rustc`` [rustc]_ +under ``--edition=2021`` [rust-editions]_. Editions are a way to introduce +small changes to the language that are not backwards compatible. + +On top of that, some unstable features [rust-unstable-features]_ are used in +the kernel. Unstable features may change in the future, thus it is an important +goal to reach a point where only stable features are used. + +Please refer to Documentation/rust/index.rst for more information. + +.. [c-language] http://www.open-std.org/jtc1/sc22/wg14/www/standards +.. [gcc] https://gcc.gnu.org +.. [clang] https://clang.llvm.org +.. [gcc-c-dialect-options] https://gcc.gnu.org/onlinedocs/gcc/C-Dialect-Options.html +.. [gnu-extensions] https://gcc.gnu.org/onlinedocs/gcc/C-Extensions.html +.. [gcc-attribute-syntax] https://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html +.. [n2049] http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2049.pdf +.. [rust-language] https://www.rust-lang.org +.. [rustc] https://doc.rust-lang.org/rustc/ +.. [rust-editions] https://doc.rust-lang.org/edition-guide/editions/ +.. [rust-unstable-features] https://github.com/Rust-for-Linux/linux/issues/2 -- cgit v1.3.1