v4: - explicitly add .ARM.attributes - split up arm64 changes into separate patches - split up arm changes into separate patches - work around Clang section generation bug in -mbranch-protection - work around Clang section generation bug in KASAN and KCSAN - split "common" ELF sections out of STABS_DEBUG - changed relative position of .comment - add reviews/acks v3: https://lore.kernel.org/lkml/20200624014940.1204448-1-keescook@xxxxxxxxxxxx/ v2: https://lore.kernel.org/lkml/20200622205815.2988115-1-keescook@xxxxxxxxxxxx/ v1: https://lore.kernel.org/lkml/20200228002244.15240-1-keescook@xxxxxxxxxxxx/ A recent bug[1] was solved for builds linked with ld.lld, and tracking it down took way longer than it needed to (a year). Ultimately, it boiled down to differences between ld.bfd and ld.lld's handling of orphan sections. Similarly, the recent FGKASLR series brough up orphan section handling too[2]. In both cases, it would have been nice if the linker was running with --orphan-handling=warn so that surprise sections wouldn't silently get mapped into the kernel image at locations up to the whim of the linker's orphan handling logic. Instead, all desired sections should be explicitly identified in the linker script (to be either kept or discarded) with any orphans throwing a warning. The powerpc architecture actually already does this, so this series extends coverage to x86, arm, and arm64. All three architectures depend on the first four commits (to vmlinux.lds.h), and arm64 depends on the 5th and 6th patches (to ctype, and efi/libstub). As such, I'd like to land this series as a whole. Given that two thirds of it is in the arm universe, perhaps this can land via the arm64 tree? If x86 -tip is preferred, that works too. Or I could just carry this myself in -next. In all cases, I would really appreciate reviews/acks/etc. :) Thanks! -Kees https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/log/?h=linker/orphans/warn/v4 Kees Cook (17): vmlinux.lds.h: Add .gnu.version* to DISCARDS vmlinux.lds.h: Avoid KASAN and KCSAN's unwanted sections vmlinux.lds.h: Split ELF_DETAILS from STABS_DEBUG vmlinux.lds.h: Add .symtab, .strtab, and .shstrtab to ELF_DETAILS ctype: Work around Clang -mbranch-protection=none bug efi/libstub: Disable -mbranch-protection arm64/build: Use common DISCARDS in linker script arm64/mm: Remove needless section quotes arm64/build: Remove .eh_frame* sections due to unwind tables arm64/kernel: Remove needless Call Frame Information annotations arm64/build: Warn on orphan section placement arm/build: Refactor linker script headers arm/build: Explicitly keep .ARM.attributes sections arm/build: Warn on orphan section placement arm/boot: Warn on orphan section placement x86/build: Warn on orphan section placement x86/boot: Warn on orphan section placement arch/alpha/kernel/vmlinux.lds.S | 1 + arch/arc/kernel/vmlinux.lds.S | 1 + arch/arm/boot/compressed/Makefile | 2 ++ arch/arm/boot/compressed/vmlinux.lds.S | 18 +++++----- .../arm/{kernel => include/asm}/vmlinux.lds.h | 25 ++++++++++--- arch/arm/kernel/vmlinux-xip.lds.S | 6 ++-- arch/arm/kernel/vmlinux.lds.S | 6 ++-- arch/arm64/Makefile | 9 ++++- arch/arm64/kernel/smccc-call.S | 2 -- arch/arm64/kernel/vmlinux.lds.S | 17 ++++++--- arch/arm64/mm/mmu.c | 2 +- arch/csky/kernel/vmlinux.lds.S | 1 + arch/hexagon/kernel/vmlinux.lds.S | 1 + arch/ia64/kernel/vmlinux.lds.S | 1 + arch/mips/kernel/vmlinux.lds.S | 1 + arch/nds32/kernel/vmlinux.lds.S | 1 + arch/nios2/kernel/vmlinux.lds.S | 1 + arch/openrisc/kernel/vmlinux.lds.S | 1 + arch/parisc/boot/compressed/vmlinux.lds.S | 1 + arch/parisc/kernel/vmlinux.lds.S | 1 + arch/powerpc/kernel/vmlinux.lds.S | 2 +- arch/riscv/kernel/vmlinux.lds.S | 1 + arch/s390/kernel/vmlinux.lds.S | 1 + arch/sh/kernel/vmlinux.lds.S | 1 + arch/sparc/kernel/vmlinux.lds.S | 1 + arch/um/kernel/dyn.lds.S | 2 +- arch/um/kernel/uml.lds.S | 2 +- arch/unicore32/kernel/vmlinux.lds.S | 1 + arch/x86/Makefile | 8 ++++- arch/x86/boot/compressed/Makefile | 3 +- arch/x86/boot/compressed/vmlinux.lds.S | 12 +++++++ arch/x86/include/asm/asm.h | 6 +++- arch/x86/kernel/vmlinux.lds.S | 7 ++++ drivers/firmware/efi/libstub/Makefile | 3 +- include/asm-generic/vmlinux.lds.h | 35 +++++++++++++++++-- lib/ctype.c | 10 ++++++ 36 files changed, 154 insertions(+), 39 deletions(-) rename arch/arm/{kernel => include/asm}/vmlinux.lds.h (88%) -- 2.25.1
