diff --git a/arch/alpha/kernel/vmlinux.lds.S b/arch/alpha/kernel/vmlinux.lds.S index bc6f727278fd..5b78d640725d 100644 --- a/arch/alpha/kernel/vmlinux.lds.S +++ b/arch/alpha/kernel/vmlinux.lds.S @@ -72,6 +72,7 @@ SECTIONS STABS_DEBUG DWARF_DEBUG + ELF_DETAILS DISCARDS } diff --git a/arch/arc/kernel/vmlinux.lds.S b/arch/arc/kernel/vmlinux.lds.S index 54139a6f469b..33ce59d91461 100644 --- a/arch/arc/kernel/vmlinux.lds.S +++ b/arch/arc/kernel/vmlinux.lds.S @@ -122,6 +122,7 @@ SECTIONS _end = . ; STABS_DEBUG + ELF_DETAILS DISCARDS .arcextmap 0 : { diff --git a/arch/arm/Makefile b/arch/arm/Makefile index 4e877354515f..e589da3c8949 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -16,6 +16,10 @@ LDFLAGS_vmlinux += --be8 KBUILD_LDFLAGS_MODULE += --be8 endif +# We never want expected sections to be placed heuristically by the +# linker. All sections should be explicitly named in the linker script. +LDFLAGS_vmlinux += $(call ld-option, --orphan-handling=warn) + ifeq ($(CONFIG_ARM_MODULE_PLTS),y) KBUILD_LDS_MODULE += $(srctree)/arch/arm/kernel/module.lds endif diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile index b1147b7f2c8d..58028abd05d9 100644 --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -123,6 +123,8 @@ endif LDFLAGS_vmlinux += --no-undefined # Delete all temporary local symbols LDFLAGS_vmlinux += -X +# Report orphan sections +LDFLAGS_vmlinux += $(call ld-option, --orphan-handling=warn) # Next argument is a linker script LDFLAGS_vmlinux += -T diff --git a/arch/arm/boot/compressed/vmlinux.lds.S b/arch/arm/boot/compressed/vmlinux.lds.S index 09ac33f52814..b914be3a207b 100644 --- a/arch/arm/boot/compressed/vmlinux.lds.S +++ b/arch/arm/boot/compressed/vmlinux.lds.S @@ -2,6 +2,7 @@ /* * Copyright (C) 2000 Russell King */ +#include #ifdef CONFIG_CPU_ENDIAN_BE8 #define ZIMAGE_MAGIC(x) ( (((x) >> 24) & 0x000000ff) | \ @@ -17,8 +18,11 @@ ENTRY(_start) SECTIONS { /DISCARD/ : { + COMMON_DISCARDS *(.ARM.exidx*) *(.ARM.extab*) + *(.note.*) + *(.rel.*) /* * Discard any r/w data - this produces a link error if we have any, * which is required for PIC decompression. Local data generates @@ -36,9 +40,7 @@ SECTIONS *(.start) *(.text) *(.text.*) - *(.gnu.warning) - *(.glue_7t) - *(.glue_7) + ARM_STUBS_TEXT } .table : ALIGN(4) { _table_start = .; @@ -128,12 +130,10 @@ SECTIONS PROVIDE(__pecoff_data_size = ALIGN(512) - ADDR(.data)); PROVIDE(__pecoff_end = ALIGN(512)); - .stab 0 : { *(.stab) } - .stabstr 0 : { *(.stabstr) } - .stab.excl 0 : { *(.stab.excl) } - .stab.exclstr 0 : { *(.stab.exclstr) } - .stab.index 0 : { *(.stab.index) } - .stab.indexstr 0 : { *(.stab.indexstr) } - .comment 0 : { *(.comment) } + STABS_DEBUG + DWARF_DEBUG + ARM_DETAILS + + ARM_ASSERTS } ASSERT(_edata_real == _edata, "error: zImage file size is incorrect"); diff --git a/arch/arm/kernel/vmlinux.lds.h b/arch/arm/include/asm/vmlinux.lds.h similarity index 84% rename from arch/arm/kernel/vmlinux.lds.h rename to arch/arm/include/asm/vmlinux.lds.h index 381a8e105fa5..4a91428c324d 100644 --- a/arch/arm/kernel/vmlinux.lds.h +++ b/arch/arm/include/asm/vmlinux.lds.h @@ -1,4 +1,5 @@ /* SPDX-License-Identifier: GPL-2.0 */ +#include #ifdef CONFIG_HOTPLUG_CPU #define ARM_CPU_DISCARD(x) @@ -49,8 +50,29 @@ EXIT_CALL \ ARM_MMU_DISCARD(*(.text.fixup)) \ ARM_MMU_DISCARD(*(__ex_table)) \ - *(.discard) \ - *(.discard.*) + COMMON_DISCARDS + +/* + * Sections that should stay zero sized, which is safer to explicitly + * check instead of blindly discarding. + */ +#define ARM_ASSERTS \ + .plt : { \ + *(.iplt) *(.rel.iplt) *(.iplt) *(.igot.plt) \ + } \ + ASSERT(SIZEOF(.plt) == 0, \ + "Unexpected run-time procedure linkages detected!") + +#define ARM_DETAILS \ + ELF_DETAILS \ + .ARM.attributes 0 : { *(.ARM.attributes) } + +#define ARM_STUBS_TEXT \ + *(.gnu.warning) \ + *(.glue_7) \ + *(.glue_7t) \ + *(.vfp11_veneer) \ + *(.v4_bx) #define ARM_TEXT \ IDMAP_TEXT \ @@ -64,9 +86,7 @@ CPUIDLE_TEXT \ LOCK_TEXT \ KPROBES_TEXT \ - *(.gnu.warning) \ - *(.glue_7) \ - *(.glue_7t) \ + ARM_STUBS_TEXT \ . = ALIGN(4); \ *(.got) /* Global offset table */ \ ARM_CPU_KEEP(PROC_INFO) diff --git a/arch/arm/kernel/vmlinux-xip.lds.S b/arch/arm/kernel/vmlinux-xip.lds.S index 6d2be994ae58..50136828f5b5 100644 --- a/arch/arm/kernel/vmlinux-xip.lds.S +++ b/arch/arm/kernel/vmlinux-xip.lds.S @@ -9,15 +9,13 @@ #include -#include +#include #include #include #include #include #include -#include "vmlinux.lds.h" - OUTPUT_ARCH(arm) ENTRY(stext) @@ -152,6 +150,10 @@ SECTIONS _end = .; STABS_DEBUG + DWARF_DEBUG + ARM_DETAILS + + ARM_ASSERTS } /* diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S index 7f24bc08403e..5f4922e858d0 100644 --- a/arch/arm/kernel/vmlinux.lds.S +++ b/arch/arm/kernel/vmlinux.lds.S @@ -9,15 +9,13 @@ #else #include -#include +#include #include #include #include #include #include -#include "vmlinux.lds.h" - OUTPUT_ARCH(arm) ENTRY(stext) @@ -151,6 +149,10 @@ SECTIONS _end = .; STABS_DEBUG + DWARF_DEBUG + ARM_DETAILS + + ARM_ASSERTS } #ifdef CONFIG_STRICT_KERNEL_RWX diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index 0fd4c1be4f64..f4717facf31e 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -28,6 +28,10 @@ LDFLAGS_vmlinux += --fix-cortex-a53-843419 endif endif +# We never want expected sections to be placed heuristically by the +# linker. All sections should be explicitly named in the linker script. +LDFLAGS_vmlinux += $(call ld-option, --orphan-handling=warn) + ifeq ($(CONFIG_ARM64_USE_LSE_ATOMICS), y) ifneq ($(CONFIG_ARM64_LSE_ATOMICS), y) $(warning LSE atomics not supported by binutils) @@ -46,13 +50,16 @@ endif KBUILD_CFLAGS += -mgeneral-regs-only \ $(compat_vdso) $(cc_has_k_constraint) -KBUILD_CFLAGS += -fno-asynchronous-unwind-tables KBUILD_CFLAGS += $(call cc-disable-warning, psabi) KBUILD_AFLAGS += $(compat_vdso) KBUILD_CFLAGS += $(call cc-option,-mabi=lp64) KBUILD_AFLAGS += $(call cc-option,-mabi=lp64) +# Avoid generating .eh_frame* sections. +KBUILD_CFLAGS += -fno-asynchronous-unwind-tables -fno-unwind-tables +KBUILD_AFLAGS += -fno-asynchronous-unwind-tables -fno-unwind-tables + ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y) prepare: stack_protector_prepare stack_protector_prepare: prepare0 diff --git a/arch/arm64/kernel/smccc-call.S b/arch/arm64/kernel/smccc-call.S index 1f93809528a4..d62447964ed9 100644 --- a/arch/arm64/kernel/smccc-call.S +++ b/arch/arm64/kernel/smccc-call.S @@ -9,7 +9,6 @@ #include .macro SMCCC instr - .cfi_startproc \instr #0 ldr x4, [sp] stp x0, x1, [x4, #ARM_SMCCC_RES_X0_OFFS] @@ -21,7 +20,6 @@ b.ne 1f str x6, [x4, ARM_SMCCC_QUIRK_STATE_OFFS] 1: ret - .cfi_endproc .endm /* diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index 82801d98a2b7..5ca957e656ab 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -6,6 +6,7 @@ */ #define RO_EXCEPTION_TABLE_ALIGN 8 +#define RUNTIME_DISCARD_EXIT #include #include @@ -96,13 +97,10 @@ SECTIONS * matching the same input section name. There is no documented * order of matching. */ + DISCARDS /DISCARD/ : { - EXIT_CALL - *(.discard) - *(.discard.*) *(.interp .dynamic) *(.dynsym .dynstr .hash .gnu.hash) - *(.eh_frame) } . = KIMAGE_VADDR; @@ -131,6 +129,14 @@ SECTIONS *(.got) /* Global offset table */ } + /* + * Make sure that the .got.plt is either completely empty or it + * contains only the lazy dispatch entries. + */ + .got.plt : { *(.got.plt) } + ASSERT(SIZEOF(.got.plt) == 0 || SIZEOF(.got.plt) == 0x18, + "Unexpected GOT/PLT entries detected!") + . = ALIGN(SEGMENT_ALIGN); _etext = .; /* End of text section */ @@ -249,8 +255,22 @@ SECTIONS _end = .; STABS_DEBUG + DWARF_DEBUG + ELF_DETAILS HEAD_SYMBOLS + + /* + * Sections that should stay zero sized, which is safer to + * explicitly check instead of blindly discarding. + */ + .plt : { + *(.plt) *(.plt.*) *(.iplt) *(.igot) + } + ASSERT(SIZEOF(.plt) == 0, "Unexpected run-time procedure linkages detected!") + + .data.rel.ro : { *(.data.rel.ro) } + ASSERT(SIZEOF(.data.rel.ro) == 0, "Unexpected RELRO detected!") } #include "image-vars.h" diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 936c4762dadf..087a844b4d26 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -43,7 +43,7 @@ u64 idmap_t0sz = TCR_T0SZ(VA_BITS); u64 idmap_ptrs_per_pgd = PTRS_PER_PGD; -u64 __section(".mmuoff.data.write") vabits_actual; +u64 __section(.mmuoff.data.write) vabits_actual; EXPORT_SYMBOL(vabits_actual); u64 kimage_voffset __ro_after_init; diff --git a/arch/csky/kernel/vmlinux.lds.S b/arch/csky/kernel/vmlinux.lds.S index f05b413df328..f03033e17c29 100644 --- a/arch/csky/kernel/vmlinux.lds.S +++ b/arch/csky/kernel/vmlinux.lds.S @@ -109,6 +109,7 @@ SECTIONS STABS_DEBUG DWARF_DEBUG + ELF_DETAILS DISCARDS } diff --git a/arch/hexagon/kernel/vmlinux.lds.S b/arch/hexagon/kernel/vmlinux.lds.S index 0ca2471ddb9f..35b18e55eae8 100644 --- a/arch/hexagon/kernel/vmlinux.lds.S +++ b/arch/hexagon/kernel/vmlinux.lds.S @@ -67,5 +67,6 @@ SECTIONS STABS_DEBUG DWARF_DEBUG + ELF_DETAILS } diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S index d259690eb91a..9b265783be6a 100644 --- a/arch/ia64/kernel/vmlinux.lds.S +++ b/arch/ia64/kernel/vmlinux.lds.S @@ -218,6 +218,7 @@ SECTIONS { STABS_DEBUG DWARF_DEBUG + ELF_DETAILS /* Default discards */ DISCARDS diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S index f185a85a27c1..5e97e9d02f98 100644 --- a/arch/mips/kernel/vmlinux.lds.S +++ b/arch/mips/kernel/vmlinux.lds.S @@ -202,6 +202,7 @@ SECTIONS STABS_DEBUG DWARF_DEBUG + ELF_DETAILS /* These must appear regardless of . */ .gptab.sdata : { diff --git a/arch/nds32/kernel/vmlinux.lds.S b/arch/nds32/kernel/vmlinux.lds.S index 7a6c1cefe3fe..6a91b965fb1e 100644 --- a/arch/nds32/kernel/vmlinux.lds.S +++ b/arch/nds32/kernel/vmlinux.lds.S @@ -64,6 +64,7 @@ SECTIONS STABS_DEBUG DWARF_DEBUG + ELF_DETAILS DISCARDS } diff --git a/arch/nios2/kernel/vmlinux.lds.S b/arch/nios2/kernel/vmlinux.lds.S index c55a7cfa1075..126e114744cb 100644 --- a/arch/nios2/kernel/vmlinux.lds.S +++ b/arch/nios2/kernel/vmlinux.lds.S @@ -58,6 +58,7 @@ SECTIONS STABS_DEBUG DWARF_DEBUG + ELF_DETAILS DISCARDS } diff --git a/arch/openrisc/kernel/vmlinux.lds.S b/arch/openrisc/kernel/vmlinux.lds.S index 22fbc5fb24b3..d5c7bb0fae57 100644 --- a/arch/openrisc/kernel/vmlinux.lds.S +++ b/arch/openrisc/kernel/vmlinux.lds.S @@ -103,6 +103,7 @@ SECTIONS /* Throw in the debugging sections */ STABS_DEBUG DWARF_DEBUG + ELF_DETAILS /* Sections to be discarded -- must be last */ DISCARDS diff --git a/arch/parisc/boot/compressed/vmlinux.lds.S b/arch/parisc/boot/compressed/vmlinux.lds.S index 2ac3a643f2eb..ab7b43990857 100644 --- a/arch/parisc/boot/compressed/vmlinux.lds.S +++ b/arch/parisc/boot/compressed/vmlinux.lds.S @@ -84,6 +84,7 @@ SECTIONS } STABS_DEBUG + ELF_DETAILS .note 0 : { *(.note) } /* Sections to be discarded */ diff --git a/arch/parisc/kernel/vmlinux.lds.S b/arch/parisc/kernel/vmlinux.lds.S index 53e29d88f99c..2769eb991f58 100644 --- a/arch/parisc/kernel/vmlinux.lds.S +++ b/arch/parisc/kernel/vmlinux.lds.S @@ -164,6 +164,7 @@ SECTIONS _end = . ; STABS_DEBUG + ELF_DETAILS .note 0 : { *(.note) } /* Sections to be discarded */ diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S index 326e113d2e45..e0548b4950de 100644 --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -360,8 +360,8 @@ SECTIONS PROVIDE32 (end = .); STABS_DEBUG - DWARF_DEBUG + ELF_DETAILS DISCARDS /DISCARD/ : { diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S index 34d00d9e6eac..67db80e12d1f 100644 --- a/arch/riscv/kernel/vmlinux.lds.S +++ b/arch/riscv/kernel/vmlinux.lds.S @@ -98,6 +98,7 @@ SECTIONS STABS_DEBUG DWARF_DEBUG + ELF_DETAILS DISCARDS } diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S index 37695499717d..177ccfbda40a 100644 --- a/arch/s390/kernel/vmlinux.lds.S +++ b/arch/s390/kernel/vmlinux.lds.S @@ -181,6 +181,7 @@ SECTIONS /* Debugging sections. */ STABS_DEBUG DWARF_DEBUG + ELF_DETAILS /* Sections to be discarded */ DISCARDS diff --git a/arch/sh/kernel/vmlinux.lds.S b/arch/sh/kernel/vmlinux.lds.S index bde7a6c01aaf..3161b9ccd2a5 100644 --- a/arch/sh/kernel/vmlinux.lds.S +++ b/arch/sh/kernel/vmlinux.lds.S @@ -76,6 +76,7 @@ SECTIONS STABS_DEBUG DWARF_DEBUG + ELF_DETAILS DISCARDS } diff --git a/arch/sparc/kernel/vmlinux.lds.S b/arch/sparc/kernel/vmlinux.lds.S index f99e99e58075..d55ae65a07ad 100644 --- a/arch/sparc/kernel/vmlinux.lds.S +++ b/arch/sparc/kernel/vmlinux.lds.S @@ -187,6 +187,7 @@ SECTIONS STABS_DEBUG DWARF_DEBUG + ELF_DETAILS DISCARDS } diff --git a/arch/um/kernel/dyn.lds.S b/arch/um/kernel/dyn.lds.S index f5001481010c..dacbfabf66d8 100644 --- a/arch/um/kernel/dyn.lds.S +++ b/arch/um/kernel/dyn.lds.S @@ -164,8 +164,8 @@ SECTIONS PROVIDE (end = .); STABS_DEBUG - DWARF_DEBUG + ELF_DETAILS DISCARDS } diff --git a/arch/um/kernel/uml.lds.S b/arch/um/kernel/uml.lds.S index 3b6dab3d4501..45d957d7004c 100644 --- a/arch/um/kernel/uml.lds.S +++ b/arch/um/kernel/uml.lds.S @@ -108,8 +108,8 @@ SECTIONS PROVIDE (end = .); STABS_DEBUG - DWARF_DEBUG + ELF_DETAILS DISCARDS } diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 4346ffb2e39f..154259f18b8b 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -209,6 +209,10 @@ ifdef CONFIG_X86_64 LDFLAGS_vmlinux += -z max-page-size=0x200000 endif +# We never want expected sections to be placed heuristically by the +# linker. All sections should be explicitly named in the linker script. +LDFLAGS_vmlinux += $(call ld-option, --orphan-handling=warn) + archscripts: scripts_basic $(Q)$(MAKE) $(build)=arch/x86/tools relocs diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index be4f2067b995..4fb989ef5665 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -29,7 +29,7 @@ targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \ vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4 vmlinux.bin.zst KBUILD_CFLAGS := -m$(BITS) -O2 -KBUILD_CFLAGS += -fno-strict-aliasing $(call cc-option, -fPIE, -fPIC) +KBUILD_CFLAGS += -fno-strict-aliasing -fPIE KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING cflags-$(CONFIG_X86_32) := -march=i386 cflags-$(CONFIG_X86_64) := -mcmodel=small @@ -43,18 +43,20 @@ KBUILD_CFLAGS += -Wno-pointer-sign KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=) KBUILD_CFLAGS += -fno-asynchronous-unwind-tables KBUILD_CFLAGS += -D__DISABLE_EXPORTS -KBUILD_CFLAGS += -include $(srctree)/$(src)/hidden.h # Disable relocation relaxation in case the link is not PIE. KBUILD_CFLAGS += $(call as-option,-Wa$(comma)-mrelax-relocations=no) +KBUILD_CFLAGS += -include $(srctree)/include/linux/hidden.h KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ GCOV_PROFILE := n UBSAN_SANITIZE :=n KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE) +KBUILD_LDFLAGS += $(call ld-option,--no-ld-generated-unwind-info) # Compressed kernel should be built as PIE since it may be loaded at any # address by the bootloader. LDFLAGS_vmlinux := -pie $(call ld-option, --no-dynamic-linker) +LDFLAGS_vmlinux += $(call ld-option, --orphan-handling=warn) LDFLAGS_vmlinux += -T hostprogs := mkpiggy diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S index 29df99b6cc64..112b2375d021 100644 --- a/arch/x86/boot/compressed/vmlinux.lds.S +++ b/arch/x86/boot/compressed/vmlinux.lds.S @@ -42,19 +42,6 @@ SECTIONS *(.rodata.*) _erodata = . ; } - .rel.dyn : { - *(.rel.*) - } - .rela.dyn : { - *(.rela.*) - } - .got : { - *(.got) - } - .got.plt : { - *(.got.plt) - } - .data : { _data = . ; *(.data) @@ -82,14 +69,49 @@ SECTIONS . = ALIGN(PAGE_SIZE); /* keep ZO size page aligned */ _end = .; + STABS_DEBUG + DWARF_DEBUG + ELF_DETAILS + DISCARDS -} + /DISCARD/ : { + *(.dynamic) *(.dynsym) *(.dynstr) *(.dynbss) + *(.hash) *(.gnu.hash) + *(.note.*) + } -ASSERT(SIZEOF(.got) == 0, "Unexpected GOT entries detected!") + .got.plt (INFO) : { + *(.got.plt) + } + ASSERT(SIZEOF(.got.plt) == 0 || #ifdef CONFIG_X86_64 -ASSERT(SIZEOF(.got.plt) == 0 || SIZEOF(.got.plt) == 0x18, "Unexpected GOT/PLT entries detected!") + SIZEOF(.got.plt) == 0x18, #else -ASSERT(SIZEOF(.got.plt) == 0 || SIZEOF(.got.plt) == 0xc, "Unexpected GOT/PLT entries detected!") + SIZEOF(.got.plt) == 0xc, #endif + "Unexpected GOT/PLT entries detected!") -ASSERT(SIZEOF(.rel.dyn) == 0 && SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations detected!") + /* + * Sections that should stay zero sized, which is safer to + * explicitly check instead of blindly discarding. + */ + .got : { + *(.got) + } + ASSERT(SIZEOF(.got) == 0, "Unexpected GOT entries detected!") + + .plt : { + *(.plt) *(.plt.*) + } + ASSERT(SIZEOF(.plt) == 0, "Unexpected run-time procedure linkages detected!") + + .rel.dyn : { + *(.rel.*) *(.rel_*) + } + ASSERT(SIZEOF(.rel.dyn) == 0, "Unexpected run-time relocations (.rel) detected!") + + .rela.dyn : { + *(.rela.*) *(.rela_*) + } + ASSERT(SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations (.rela) detected!") +} diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h index 0359cbbd0f50..0603c7423aca 100644 --- a/arch/x86/include/asm/asm.h +++ b/arch/x86/include/asm/asm.h @@ -141,11 +141,15 @@ # define _ASM_EXTABLE_FAULT(from, to) \ _ASM_EXTABLE_HANDLE(from, to, ex_handler_fault) -# define _ASM_NOKPROBE(entry) \ +# ifdef CONFIG_KPROBES +# define _ASM_NOKPROBE(entry) \ .pushsection "_kprobe_blacklist","aw" ; \ _ASM_ALIGN ; \ _ASM_PTR (entry); \ .popsection +# else +# define _ASM_NOKPROBE(entry) +# endif #else /* ! __ASSEMBLY__ */ # define _EXPAND_EXTABLE_HANDLE(x) #x diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 9a03e5b23135..45d72447df84 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -411,10 +411,47 @@ SECTIONS STABS_DEBUG DWARF_DEBUG + ELF_DETAILS DISCARDS -} + /* + * Make sure that the .got.plt is either completely empty or it + * contains only the lazy dispatch entries. + */ + .got.plt (INFO) : { *(.got.plt) } + ASSERT(SIZEOF(.got.plt) == 0 || +#ifdef CONFIG_X86_64 + SIZEOF(.got.plt) == 0x18, +#else + SIZEOF(.got.plt) == 0xc, +#endif + "Unexpected GOT/PLT entries detected!") + + /* + * Sections that should stay zero sized, which is safer to + * explicitly check instead of blindly discarding. + */ + .got : { + *(.got) *(.igot.*) + } + ASSERT(SIZEOF(.got) == 0, "Unexpected GOT entries detected!") + + .plt : { + *(.plt) *(.plt.*) *(.iplt) + } + ASSERT(SIZEOF(.plt) == 0, "Unexpected run-time procedure linkages detected!") + + .rel.dyn : { + *(.rel.*) *(.rel_*) + } + ASSERT(SIZEOF(.rel.dyn) == 0, "Unexpected run-time relocations (.rel) detected!") + + .rela.dyn : { + *(.rela.*) *(.rela_*) + } + ASSERT(SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations (.rela) detected!") +} #ifdef CONFIG_X86_32 /* diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 5a80cf6bd606..039a9acab817 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -18,7 +18,8 @@ cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ \ # arm64 uses the full KBUILD_CFLAGS so it's necessary to explicitly # disable the stackleak plugin cflags-$(CONFIG_ARM64) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ - -fpie $(DISABLE_STACKLEAK_PLUGIN) + -fpie $(DISABLE_STACKLEAK_PLUGIN) \ + $(call cc-option,-mbranch-protection=none) cflags-$(CONFIG_ARM) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ -fno-builtin -fpic \ $(call cc-option,-mno-single-pic-base) @@ -26,7 +27,7 @@ cflags-$(CONFIG_ARM) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ cflags-$(CONFIG_EFI_GENERIC_STUB) += -I$(srctree)/scripts/dtc/libfdt KBUILD_CFLAGS := $(cflags-y) -Os -DDISABLE_BRANCH_PROFILING \ - -include $(srctree)/drivers/firmware/efi/libstub/hidden.h \ + -include $(srctree)/include/linux/hidden.h \ -D__NO_FORTIFY \ -ffreestanding \ -fno-stack-protector \ @@ -65,6 +66,12 @@ lib-$(CONFIG_ARM64) += arm64-stub.o lib-$(CONFIG_X86) += x86-stub.o CFLAGS_arm32-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) +# Even when -mbranch-protection=none is set, Clang will generate a +# .note.gnu.property for code-less object files (like lib/ctype.c), +# so work around this by explicitly removing the unwanted section. +# https://bugs.llvm.org/show_bug.cgi?id=46480 +STUBCOPY_FLAGS-y += --remove-section=.note.gnu.property + # # For x86, bootloaders like systemd-boot or grub-efi do not zero-initialize the # .bss section, so the .bss section of the EFI stub needs to be included in the diff --git a/drivers/firmware/efi/libstub/hidden.h b/drivers/firmware/efi/libstub/hidden.h deleted file mode 100644 index 3493b041f419..000000000000 --- a/drivers/firmware/efi/libstub/hidden.h +++ /dev/null @@ -1,6 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * To prevent the compiler from emitting GOT-indirected (and thus absolute) - * references to any global symbols, override their visibility as 'hidden' - */ -#pragma GCC visibility push(hidden) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 7636bc71c71f..b33577d2e5ee 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -34,6 +34,7 @@ * * STABS_DEBUG * DWARF_DEBUG + * ELF_DETAILS * * DISCARDS // must be the last * } @@ -581,7 +582,10 @@ */ #define TEXT_TEXT \ ALIGN_FUNCTION(); \ - *(.text.hot TEXT_MAIN .text.fixup .text.unlikely) \ + *(.text.hot .text.hot.*) \ + *(TEXT_MAIN .text.fixup) \ + *(.text.unlikely .text.unlikely.*) \ + *(.text.unknown .text.unknown.*) \ NOINSTR_TEXT \ *(.text..refcount) \ *(.ref.text) \ @@ -812,15 +816,21 @@ .debug_macro 0 : { *(.debug_macro) } \ .debug_addr 0 : { *(.debug_addr) } - /* Stabs debugging sections. */ +/* Stabs debugging sections. */ #define STABS_DEBUG \ .stab 0 : { *(.stab) } \ .stabstr 0 : { *(.stabstr) } \ .stab.excl 0 : { *(.stab.excl) } \ .stab.exclstr 0 : { *(.stab.exclstr) } \ .stab.index 0 : { *(.stab.index) } \ - .stab.indexstr 0 : { *(.stab.indexstr) } \ - .comment 0 : { *(.comment) } + .stab.indexstr 0 : { *(.stab.indexstr) } + +/* Required sections not related to debugging. */ +#define ELF_DETAILS \ + .comment 0 : { *(.comment) } \ + .symtab 0 : { *(.symtab) } \ + .strtab 0 : { *(.strtab) } \ + .shstrtab 0 : { *(.shstrtab) } #ifdef CONFIG_GENERIC_BUG #define BUG_TABLE \ @@ -955,13 +965,38 @@ EXIT_DATA #endif +/* + * Clang's -fsanitize=kernel-address and -fsanitize=thread produce + * unwanted sections (.eh_frame and .init_array.*), but + * CONFIG_CONSTRUCTORS wants to keep any .init_array.* sections. + * https://bugs.llvm.org/show_bug.cgi?id=46478 + */ +#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KCSAN) +# ifdef CONFIG_CONSTRUCTORS +# define SANITIZER_DISCARDS \ + *(.eh_frame) +# else +# define SANITIZER_DISCARDS \ + *(.init_array) *(.init_array.*) \ + *(.eh_frame) +# endif +#else +# define SANITIZER_DISCARDS +#endif + +#define COMMON_DISCARDS \ + SANITIZER_DISCARDS \ + *(.discard) \ + *(.discard.*) \ + *(.modinfo) \ + /* ld.bfd warns about .gnu.version* even when not emitted */ \ + *(.gnu.version*) \ + #define DISCARDS \ /DISCARD/ : { \ EXIT_DISCARDS \ EXIT_CALL \ - *(.discard) \ - *(.discard.*) \ - *(.modinfo) \ + COMMON_DISCARDS \ } /** diff --git a/include/linux/hidden.h b/include/linux/hidden.h new file mode 100644 index 000000000000..49a17b6b5962 --- /dev/null +++ b/include/linux/hidden.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * When building position independent code with GCC using the -fPIC option, + * (or even the -fPIE one on older versions), it will assume that we are + * building a dynamic object (either a shared library or an executable) that + * may have symbol references that can only be resolved at load time. For a + * variety of reasons (ELF symbol preemption, the CoW footprint of the section + * that is modified by the loader), this results in all references to symbols + * with external linkage to go via entries in the Global Offset Table (GOT), + * which carries absolute addresses which need to be fixed up when the + * executable image is loaded at an offset which is different from its link + * time offset. + * + * Fortunately, there is a way to inform the compiler that such symbol + * references will be satisfied at link time rather than at load time, by + * giving them 'hidden' visibility. + */ + +#pragma GCC visibility push(hidden)