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-rw-r--r--Documentation/kbuild/gcc-plugins.rst26
-rw-r--r--scripts/gcc-plugins/Kconfig4
-rw-r--r--security/Kconfig.hardening9
3 files changed, 34 insertions, 5 deletions
diff --git a/Documentation/kbuild/gcc-plugins.rst b/Documentation/kbuild/gcc-plugins.rst
index 3349966f213d..4b28c7a4032f 100644
--- a/Documentation/kbuild/gcc-plugins.rst
+++ b/Documentation/kbuild/gcc-plugins.rst
@@ -32,6 +32,32 @@ This infrastructure was ported from grsecurity [6]_ and PaX [7]_.
.. [7] https://pax.grsecurity.net/
+Purpose
+=======
+
+GCC plugins are designed to provide a place to experiment with potential
+compiler features that are neither in GCC nor Clang upstream. Once
+their utility is proven, the goal is to upstream the feature into GCC
+(and Clang), and then to finally remove them from the kernel once the
+feature is available in all supported versions of GCC.
+
+Specifically, new plugins should implement only features that have no
+upstream compiler support (in either GCC or Clang).
+
+When a feature exists in Clang but not GCC, effort should be made to
+bring the feature to upstream GCC (rather than just as a kernel-specific
+GCC plugin), so the entire ecosystem can benefit from it.
+
+Similarly, even if a feature provided by a GCC plugin does *not* exist
+in Clang, but the feature is proven to be useful, effort should be spent
+to upstream the feature to GCC (and Clang).
+
+After a feature is available in upstream GCC, the plugin will be made
+unbuildable for the corresponding GCC version (and later). Once all
+kernel-supported versions of GCC provide the feature, the plugin will
+be removed from the kernel.
+
+
Files
=====
diff --git a/scripts/gcc-plugins/Kconfig b/scripts/gcc-plugins/Kconfig
index ab9eb4cbe33a..7c7ba3b0d3cd 100644
--- a/scripts/gcc-plugins/Kconfig
+++ b/scripts/gcc-plugins/Kconfig
@@ -37,6 +37,8 @@ config GCC_PLUGIN_CYC_COMPLEXITY
config GCC_PLUGIN_SANCOV
bool
+ # Plugin can be removed once the kernel only supports GCC 6+
+ depends on !CC_HAS_SANCOV_TRACE_PC
help
This plugin inserts a __sanitizer_cov_trace_pc() call at the start of
basic blocks. It supports all gcc versions with plugin support (from
@@ -83,8 +85,6 @@ config GCC_PLUGIN_RANDSTRUCT
the existing seed and will be removed by a make mrproper or
make distclean.
- Note that the implementation requires gcc 4.7 or newer.
-
This plugin was ported from grsecurity/PaX. More information at:
* https://grsecurity.net/
* https://pax.grsecurity.net/
diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening
index ded17b8abce2..d051f8ceefdd 100644
--- a/security/Kconfig.hardening
+++ b/security/Kconfig.hardening
@@ -56,7 +56,8 @@ choice
config GCC_PLUGIN_STRUCTLEAK_USER
bool "zero-init structs marked for userspace (weak)"
- depends on GCC_PLUGINS
+ # Plugin can be removed once the kernel only supports GCC 12+
+ depends on GCC_PLUGINS && !CC_HAS_AUTO_VAR_INIT_ZERO
select GCC_PLUGIN_STRUCTLEAK
help
Zero-initialize any structures on the stack containing
@@ -67,7 +68,8 @@ choice
config GCC_PLUGIN_STRUCTLEAK_BYREF
bool "zero-init structs passed by reference (strong)"
- depends on GCC_PLUGINS
+ # Plugin can be removed once the kernel only supports GCC 12+
+ depends on GCC_PLUGINS && !CC_HAS_AUTO_VAR_INIT_ZERO
depends on !(KASAN && KASAN_STACK)
select GCC_PLUGIN_STRUCTLEAK
help
@@ -85,7 +87,8 @@ choice
config GCC_PLUGIN_STRUCTLEAK_BYREF_ALL
bool "zero-init everything passed by reference (very strong)"
- depends on GCC_PLUGINS
+ # Plugin can be removed once the kernel only supports GCC 12+
+ depends on GCC_PLUGINS && !CC_HAS_AUTO_VAR_INIT_ZERO
depends on !(KASAN && KASAN_STACK)
select GCC_PLUGIN_STRUCTLEAK
help