From: Sami Tolvanen samitolvanen@google.com
[ Upstream commit ddf56288eebd1fe82c46fc9f693b5b18045cddb6 ]
With GCOV_PROFILE_ALL, Clang injects __llvm_gcov_* functions to each object file, and the functions are indirectly called during boot. However, when code is injected to object files that are not part of vmlinux.o, it's also not processed by objtool, which breaks CFI hash randomization as the hashes in these files won't be included in the .cfi_sites section and thus won't be randomized.
Similarly to commit 42633ed852de ("kbuild: Fix CFI hash randomization with KASAN"), disable GCOV for .vmlinux.export.o and init/version-timestamp.o to avoid emitting unnecessary functions to object files that don't otherwise have executable code.
Fixes: 0c3e806ec0f9 ("x86/cfi: Add boot time hash randomization") Reported-by: Joe Fradley joefradley@google.com Signed-off-by: Sami Tolvanen samitolvanen@google.com Acked-by: Peter Zijlstra (Intel) peterz@infradead.org Reviewed-by: Kees Cook keescook@chromium.org Reviewed-by: Nick Desaulniers ndesaulniers@google.com Signed-off-by: Masahiro Yamada masahiroy@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- init/Makefile | 1 + scripts/Makefile.vmlinux | 1 + 2 files changed, 2 insertions(+)
diff --git a/init/Makefile b/init/Makefile index 26de459006c4e..ec557ada3c12e 100644 --- a/init/Makefile +++ b/init/Makefile @@ -60,3 +60,4 @@ include/generated/utsversion.h: FORCE $(obj)/version-timestamp.o: include/generated/utsversion.h CFLAGS_version-timestamp.o := -include include/generated/utsversion.h KASAN_SANITIZE_version-timestamp.o := n +GCOV_PROFILE_version-timestamp.o := n diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux index 10176dec97eac..3cd6ca15f390d 100644 --- a/scripts/Makefile.vmlinux +++ b/scripts/Makefile.vmlinux @@ -19,6 +19,7 @@ quiet_cmd_cc_o_c = CC $@
ifdef CONFIG_MODULES KASAN_SANITIZE_.vmlinux.export.o := n +GCOV_PROFILE_.vmlinux.export.o := n targets += .vmlinux.export.o vmlinux: .vmlinux.export.o endif