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authorMarco Elver <elver@google.com>2022-01-31 12:05:20 +0300
committerKees Cook <keescook@chromium.org>2022-02-14 22:07:12 +0300
commit8cb37a5974a48569aab8a1736d21399fddbdbdb2 (patch)
treeb7c766fc7e31649c8fabc0c53cefc6c278740ea1 /init
parentae978009fc013e3166c9f523f8b17e41a3c0286e (diff)
downloadlinux-8cb37a5974a48569aab8a1736d21399fddbdbdb2.tar.xz
stack: Introduce CONFIG_RANDOMIZE_KSTACK_OFFSET
The randomize_kstack_offset feature is unconditionally compiled in when the architecture supports it. To add constraints on compiler versions, we require a dedicated Kconfig variable. Therefore, introduce RANDOMIZE_KSTACK_OFFSET. Furthermore, this option is now also configurable by EXPERT kernels: while the feature is supposed to have zero performance overhead when disabled, due to its use of static branches, there are few cases where giving a distribution the option to disable the feature entirely makes sense. For example, in very resource constrained environments, which would never enable the feature to begin with, in which case the additional kernel code size increase would be redundant. Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220131090521.1947110-1-elver@google.com
Diffstat (limited to 'init')
-rw-r--r--init/main.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/init/main.c b/init/main.c
index 65fa2e41a9c0..560f45c27ffe 100644
--- a/init/main.c
+++ b/init/main.c
@@ -853,7 +853,7 @@ static void __init mm_init(void)
pti_init();
}
-#ifdef CONFIG_HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
+#ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET
DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,
randomize_kstack_offset);
DEFINE_PER_CPU(u32, kstack_offset);