When generating Runtime Calls, Clang doesn't respect the -mregparm=3 option used on i386. Hopefully this will be fixed correctly in Clang 19: https://github.com/llvm/llvm-project/pull/89707 but we need to fix this for earlier Clang versions today. Force the calling convention to use non-register arguments.
Reported-by: Erhard Furtner <[email protected]> Closes: https://github.com/KSPP/linux/issues/350 Signed-off-by: Kees Cook <[email protected]> --- Cc: Marco Elver <[email protected]> Cc: Andrey Konovalov <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: Nathan Chancellor <[email protected]> Cc: Nick Desaulniers <[email protected]> Cc: Bill Wendling <[email protected]> Cc: Justin Stitt <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] v2: - use email address in Reported-by - link to upstream llvm bug in ubsan.h comment - drop needless /**/ - explicitly test Clang version v1: https://lore.kernel.org/lkml/[email protected]/ --- lib/ubsan.h | 41 +++++++++++++++++++++++++++-------------- 1 file changed, 27 insertions(+), 14 deletions(-) diff --git a/lib/ubsan.h b/lib/ubsan.h index 50ef50811b7c..07e37d4429b4 100644 --- a/lib/ubsan.h +++ b/lib/ubsan.h @@ -124,19 +124,32 @@ typedef s64 s_max; typedef u64 u_max; #endif -void __ubsan_handle_add_overflow(void *data, void *lhs, void *rhs); -void __ubsan_handle_sub_overflow(void *data, void *lhs, void *rhs); -void __ubsan_handle_mul_overflow(void *data, void *lhs, void *rhs); -void __ubsan_handle_negate_overflow(void *_data, void *old_val); -void __ubsan_handle_divrem_overflow(void *_data, void *lhs, void *rhs); -void __ubsan_handle_type_mismatch(struct type_mismatch_data *data, void *ptr); -void __ubsan_handle_type_mismatch_v1(void *_data, void *ptr); -void __ubsan_handle_out_of_bounds(void *_data, void *index); -void __ubsan_handle_shift_out_of_bounds(void *_data, void *lhs, void *rhs); -void __ubsan_handle_builtin_unreachable(void *_data); -void __ubsan_handle_load_invalid_value(void *_data, void *val); -void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr, - unsigned long align, - unsigned long offset); +/* + * When generating Runtime Calls, Clang doesn't respect the -mregparm=3 + * option used on i386: https://github.com/llvm/llvm-project/issues/89670 + * Fix this for earlier Clang versions by forcing the calling convention + * to use non-register arguments. + */ +#if defined(CONFIG_X86_32) && \ + defined(CONFIG_CC_IS_CLANG) && CONFIG_CLANG_VERSION < 190000 +# define ubsan_linkage asmlinkage +#else +# define ubsan_linkage +#endif + +void ubsan_linkage __ubsan_handle_add_overflow(void *data, void *lhs, void *rhs); +void ubsan_linkage __ubsan_handle_sub_overflow(void *data, void *lhs, void *rhs); +void ubsan_linkage __ubsan_handle_mul_overflow(void *data, void *lhs, void *rhs); +void ubsan_linkage __ubsan_handle_negate_overflow(void *_data, void *old_val); +void ubsan_linkage __ubsan_handle_divrem_overflow(void *_data, void *lhs, void *rhs); +void ubsan_linkage __ubsan_handle_type_mismatch(struct type_mismatch_data *data, void *ptr); +void ubsan_linkage __ubsan_handle_type_mismatch_v1(void *_data, void *ptr); +void ubsan_linkage __ubsan_handle_out_of_bounds(void *_data, void *index); +void ubsan_linkage __ubsan_handle_shift_out_of_bounds(void *_data, void *lhs, void *rhs); +void ubsan_linkage __ubsan_handle_builtin_unreachable(void *_data); +void ubsan_linkage __ubsan_handle_load_invalid_value(void *_data, void *val); +void ubsan_linkage __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr, + unsigned long align, + unsigned long offset); #endif -- 2.34.1
