When CONFIG_KASAN is set, we can run into some code that uses incredible amounts of kernel stack:
drivers/staging/dgnc/dgnc_neo.c:1056:1: error: the frame size of 11112 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] drivers/media/i2c/cx25840/cx25840-core.c:4960:1: error: the frame size of 94000 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] drivers/media/dvb-frontends/stv090x.c:3430:1: error: the frame size of 5312 bytes is larger than 3072 bytes [-Werror=frame-larger-than=] This happens when a sanitizer uses stack memory each time an inline function gets called. This introduces a new annotation for those functions to make them either 'inline' or 'noinline' depending on the CONFIG_KASAN symbol. Signed-off-by: Arnd Bergmann <a...@arndb.de> --- include/linux/compiler.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 219f82f3ec1a..a402c43c07d2 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -412,6 +412,17 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s */ #define noinline_for_stack noinline +/* + * CONFIG_KASAN can lead to extreme stack usage with certain patterns when + * one function gets inlined many times and each instance requires a stack + * ckeck. + */ +#ifdef CONFIG_KASAN +#define noinline_if_stackbloat noinline __maybe_unused +#else +#define noinline_if_stackbloat inline +#endif + #ifndef __always_inline #define __always_inline inline #endif -- 2.9.0
