From c0dd671686b2229e888ede77682ab0633b2a0dd7 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Sun, 28 Feb 2016 22:22:34 -0600 Subject: objtool: Mark non-standard object files and directories Code which runs outside the kernel's normal mode of operation often does unusual things which can cause a static analysis tool like objtool to emit false positive warnings: - boot image - vdso image - relocation - realmode - efi - head - purgatory - modpost Set OBJECT_FILES_NON_STANDARD for their related files and directories, which will tell objtool to skip checking them. It's ok to skip them because they don't affect runtime stack traces. Also skip the following code which does the right thing with respect to frame pointers, but is too "special" to be validated by a tool: - entry - mcount Also skip the test_nx module because it modifies its exception handling table at runtime, which objtool can't understand. Fortunately it's just a test module so it doesn't matter much. Currently objtool is the only user of OBJECT_FILES_NON_STANDARD, but it might eventually be useful for other tools. Signed-off-by: Josh Poimboeuf Cc: Andrew Morton Cc: Andy Lutomirski Cc: Arnaldo Carvalho de Melo Cc: Bernd Petrovitsch Cc: Borislav Petkov Cc: Chris J Arges Cc: Jiri Slaby Cc: Linus Torvalds Cc: Michal Marek Cc: Namhyung Kim Cc: Pedro Alves Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/366c080e3844e8a5b6a0327dc7e8c2b90ca3baeb.1456719558.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/boot/Makefile | 3 ++- arch/x86/boot/compressed/Makefile | 3 ++- arch/x86/entry/Makefile | 4 ++++ arch/x86/entry/vdso/Makefile | 6 ++++-- arch/x86/kernel/Makefile | 11 ++++++++--- arch/x86/platform/efi/Makefile | 2 ++ arch/x86/purgatory/Makefile | 2 ++ arch/x86/realmode/Makefile | 4 +++- arch/x86/realmode/rm/Makefile | 3 ++- drivers/firmware/efi/libstub/Makefile | 1 + scripts/mod/Makefile | 2 ++ 11 files changed, 32 insertions(+), 9 deletions(-) diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile index bbe1a62..0bf6749 100644 --- a/arch/x86/boot/Makefile +++ b/arch/x86/boot/Makefile @@ -9,7 +9,8 @@ # Changed by many, many contributors over the years. # -KASAN_SANITIZE := n +KASAN_SANITIZE := n +OBJECT_FILES_NON_STANDARD := y # If you want to preset the SVGA mode, uncomment the next line and # set SVGA_MODE to whatever number you want. diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index f9ce75d..5e1d26e 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -16,7 +16,8 @@ # (see scripts/Makefile.lib size_append) # compressed vmlinux.bin.all + u32 size of vmlinux.bin.all -KASAN_SANITIZE := n +KASAN_SANITIZE := n +OBJECT_FILES_NON_STANDARD := y targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \ vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4 diff --git a/arch/x86/entry/Makefile b/arch/x86/entry/Makefile index bd55ded..fe91c25 100644 --- a/arch/x86/entry/Makefile +++ b/arch/x86/entry/Makefile @@ -1,6 +1,10 @@ # # Makefile for the x86 low level entry code # + +OBJECT_FILES_NON_STANDARD_entry_$(BITS).o := y +OBJECT_FILES_NON_STANDARD_entry_64_compat.o := y + obj-y := entry_$(BITS).o thunk_$(BITS).o syscall_$(BITS).o obj-y += common.o diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile index c854541..f9fb859 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -3,8 +3,9 @@ # KBUILD_CFLAGS += $(DISABLE_LTO) -KASAN_SANITIZE := n -UBSAN_SANITIZE := n +KASAN_SANITIZE := n +UBSAN_SANITIZE := n +OBJECT_FILES_NON_STANDARD := y VDSO64-$(CONFIG_X86_64) := y VDSOX32-$(CONFIG_X86_X32_ABI) := y @@ -16,6 +17,7 @@ vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o # files to link into kernel obj-y += vma.o +OBJECT_FILES_NON_STANDARD_vma.o := n # vDSO images to build vdso_img-$(VDSO64-y) += 64 diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index b1b78ff..d5fb087 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -16,9 +16,14 @@ CFLAGS_REMOVE_ftrace.o = -pg CFLAGS_REMOVE_early_printk.o = -pg endif -KASAN_SANITIZE_head$(BITS).o := n -KASAN_SANITIZE_dumpstack.o := n -KASAN_SANITIZE_dumpstack_$(BITS).o := n +KASAN_SANITIZE_head$(BITS).o := n +KASAN_SANITIZE_dumpstack.o := n +KASAN_SANITIZE_dumpstack_$(BITS).o := n + +OBJECT_FILES_NON_STANDARD_head_$(BITS).o := y +OBJECT_FILES_NON_STANDARD_relocate_kernel_$(BITS).o := y +OBJECT_FILES_NON_STANDARD_mcount_$(BITS).o := y +OBJECT_FILES_NON_STANDARD_test_nx.o := y CFLAGS_irq.o := -I$(src)/../include/asm/trace diff --git a/arch/x86/platform/efi/Makefile b/arch/x86/platform/efi/Makefile index 2846aaa..066619b 100644 --- a/arch/x86/platform/efi/Makefile +++ b/arch/x86/platform/efi/Makefile @@ -1,3 +1,5 @@ +OBJECT_FILES_NON_STANDARD_efi_thunk_$(BITS).o := y + obj-$(CONFIG_EFI) += quirks.o efi.o efi_$(BITS).o efi_stub_$(BITS).o obj-$(CONFIG_ACPI_BGRT) += efi-bgrt.o obj-$(CONFIG_EARLY_PRINTK_EFI) += early_printk.o diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile index 2c835e3..92e3e1d 100644 --- a/arch/x86/purgatory/Makefile +++ b/arch/x86/purgatory/Makefile @@ -1,3 +1,5 @@ +OBJECT_FILES_NON_STANDARD := y + purgatory-y := purgatory.o stack.o setup-x86_$(BITS).o sha256.o entry64.o string.o targets += $(purgatory-y) diff --git a/arch/x86/realmode/Makefile b/arch/x86/realmode/Makefile index e02c2c6..682c895 100644 --- a/arch/x86/realmode/Makefile +++ b/arch/x86/realmode/Makefile @@ -6,7 +6,9 @@ # for more details. # # -KASAN_SANITIZE := n +KASAN_SANITIZE := n +OBJECT_FILES_NON_STANDARD := y + subdir- := rm obj-y += init.o diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile index 3e75fcf..053abe7b0 100644 --- a/arch/x86/realmode/rm/Makefile +++ b/arch/x86/realmode/rm/Makefile @@ -6,7 +6,8 @@ # for more details. # # -KASAN_SANITIZE := n +KASAN_SANITIZE := n +OBJECT_FILES_NON_STANDARD := y always := realmode.bin realmode.relocs diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index aaf9c0b..68fa977 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -23,6 +23,7 @@ KBUILD_CFLAGS := $(cflags-y) -DDISABLE_BRANCH_PROFILING \ GCOV_PROFILE := n KASAN_SANITIZE := n UBSAN_SANITIZE := n +OBJECT_FILES_NON_STANDARD := y lib-y := efi-stub-helper.o diff --git a/scripts/mod/Makefile b/scripts/mod/Makefile index c11212f..19d9bca 100644 --- a/scripts/mod/Makefile +++ b/scripts/mod/Makefile @@ -1,3 +1,5 @@ +OBJECT_FILES_NON_STANDARD := y + hostprogs-y := modpost mk_elfconfig always := $(hostprogs-y) empty.o -- cgit v1.1