From c0dd671686b2229e888ede77682ab0633b2a0dd7 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Sun, 28 Feb 2016 22:22:34 -0600 Subject: [PATCH] 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 bbe1a62efc021..0bf6749522d9f 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 f9ce75d80101c..5e1d26e094076 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 bd55dedd7614a..fe91c25092da2 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 c854541d93ff6..f9fb859c98b97 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 b1b78ffe01d06..d5fb0871aba3f 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 2846aaab51035..066619b0700c9 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 2c835e356349b..92e3e1d84c1d7 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 e02c2c6c56a57..682c895753d96 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 3e75fcf6b8362..053abe7b0ef76 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 aaf9c0bab42e8..68fa977b2c1b7 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 c11212ff35105..19d9bcadc0ccd 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 -- 2.30.2