Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Date | Fri, 29 Apr 2022 13:36:36 -0700 | Subject | [RFC PATCH 13/21] cfi: Add the cfi_unchecked macro | From | Sami Tolvanen <> |
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The cfi_unchecked macro allows CFI checking to be disabled for a specific indirect call expression, by passing the expression as an argument to the macro. For example:
static void call(void (*f)(void)) { cfi_unchecked(f()); }
Signed-off-by: Sami Tolvanen <samitolvanen@google.com> --- include/linux/compiler-clang.h | 2 ++ include/linux/compiler_types.h | 4 ++++ 2 files changed, 6 insertions(+)
diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h index c4ff42859077..0d6a0e7e36dc 100644 --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -94,4 +94,6 @@ #if CONFIG_CFI_CLANG /* Disable CFI checking inside a function. */ #define __nocfi __attribute__((__no_sanitize__("kcfi"))) +/* Disable CFI checking for the indirect call expression. */ +#define cfi_unchecked(expr) __builtin_kcfi_call_unchecked(expr) #endif diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index bdd2526af46a..41f547fe9724 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -263,6 +263,10 @@ struct ftrace_likely_data { # define __nocfi #endif +#ifndef cfi_unchecked +# define cfi_unchecked(expr) expr +#endif + /* * Any place that could be marked with the "alloc_size" attribute is also * a place to be marked with the "malloc" attribute. Do this as part of the -- 2.36.0.464.gb9c8b46e94-goog
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