From e75a698859a3f62825af06987da6b3e6466e6e56 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 15 Feb 2023 14:00:57 +0100 Subject: [PATCH] kmsan: disable ftrace in kmsan core code objtool warns about some suspicous code inside of kmsan: vmlinux.o: warning: objtool: __msan_metadata_ptr_for_load_n+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_store_n+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_load_1+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_store_1+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_load_2+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_store_2+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_load_4+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_store_4+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_load_8+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_store_8+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_instrument_asm_store+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_chain_origin+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_poison_alloca+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_warning+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_get_context_state+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: kmsan_copy_to_user+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: kmsan_unpoison_memory+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: kmsan_unpoison_entry_regs+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: kmsan_report+0x4: call to __fentry__() with UACCESS enabled The Makefile contained a line to turn off ftrace for the entire directory, but this does not work. Replace it with individual lines, matching the approach in kasan. Link: https://lkml.kernel.org/r/20230215130058.3836177-3-arnd@kernel.org Signed-off-by: Arnd Bergmann Fixes: f80be4571b19 ("kmsan: add KMSAN runtime core") Acked-by: Alexander Potapenko Cc: Andrey Konovalov Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Josh Poimboeuf Cc: Kuan-Ying Lee Cc: Marco Elver Cc: Peter Zijlstra (Intel) Cc: Vincenzo Frascino Signed-off-by: Andrew Morton --- mm/kmsan/Makefile | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/mm/kmsan/Makefile b/mm/kmsan/Makefile index 98eab2856626..91cfdde642d1 100644 --- a/mm/kmsan/Makefile +++ b/mm/kmsan/Makefile @@ -14,7 +14,13 @@ CC_FLAGS_KMSAN_RUNTIME := -fno-stack-protector CC_FLAGS_KMSAN_RUNTIME += $(call cc-option,-fno-conserve-stack) CC_FLAGS_KMSAN_RUNTIME += -DDISABLE_BRANCH_PROFILING -CFLAGS_REMOVE.o = $(CC_FLAGS_FTRACE) +# Disable ftrace to avoid recursion. +CFLAGS_REMOVE_core.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_hooks.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_init.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_instrumentation.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_report.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_shadow.o = $(CC_FLAGS_FTRACE) CFLAGS_core.o := $(CC_FLAGS_KMSAN_RUNTIME) CFLAGS_hooks.o := $(CC_FLAGS_KMSAN_RUNTIME)