In preparation for adding arm64 support for "objtool klp checksum/diff" to enable livepatch module generation, annotate special section entries.
This will allow objtool to determine the size and location of the entries and to extract them when needed. A new ANNOTATE_DATA_SPECIAL_END annotation is added to mark the end of special data blocks, which is needed because arm64's replacement instructions are emitted in .text rather than .altinstr_replacement, so there's otherwise no way to determine where the last replacement block ends. Signed-off-by: Josh Poimboeuf <[email protected]> --- arch/arm64/include/asm/alternative-macros.h | 27 ++++++++++++++++----- arch/arm64/include/asm/asm-bug.h | 2 ++ arch/arm64/include/asm/asm-extable.h | 21 ++++++++++------ arch/arm64/include/asm/jump_label.h | 2 ++ arch/arm64/kernel/asm-offsets.c | 5 ++++ include/linux/annotate.h | 14 ++++++++++- include/linux/objtool_types.h | 1 + tools/include/linux/objtool_types.h | 1 + tools/objtool/klp-diff.c | 5 +++- 9 files changed, 62 insertions(+), 16 deletions(-) diff --git a/arch/arm64/include/asm/alternative-macros.h b/arch/arm64/include/asm/alternative-macros.h index 8624166248528..ba86d655af1d7 100644 --- a/arch/arm64/include/asm/alternative-macros.h +++ b/arch/arm64/include/asm/alternative-macros.h @@ -3,11 +3,16 @@ #define __ASM_ALTERNATIVE_MACROS_H #include <linux/const.h> +#include <linux/annotate.h> #include <vdso/bits.h> #include <asm/cpucaps.h> #include <asm/insn-def.h> +#ifndef COMPILE_OFFSETS +#include <asm/asm-offsets.h> +#endif + /* * Binutils 2.27.0 can't handle a 'UL' suffix on constants, so for the assembly * macros below we must use we must use `(1 << ARM64_CB_SHIFT)`. @@ -58,15 +63,18 @@ "661:\n\t" \ oldinstr "\n" \ "662:\n" \ - ".pushsection .altinstructions,\"a\"\n" \ + ".pushsection .altinstructions,\"aM\", @progbits, " \ + __stringify(ALT_INSTR_SIZE) "\n" \ ALTINSTR_ENTRY(cpucap) \ ".popsection\n" \ ".subsection 1\n" \ + ANNOTATE_DATA_SPECIAL "\n" \ "663:\n\t" \ newinstr "\n" \ "664:\n\t" \ ".org . - (664b-663b) + (662b-661b)\n\t" \ ".org . - (662b-661b) + (664b-663b)\n\t" \ + ANNOTATE_DATA_SPECIAL_END "\n\t" \ ".previous\n" \ ".endif\n" @@ -75,7 +83,8 @@ "661:\n\t" \ oldinstr "\n" \ "662:\n" \ - ".pushsection .altinstructions,\"a\"\n" \ + ".pushsection .altinstructions,\"aM\", @progbits, " \ + __stringify(ALT_INSTR_SIZE) "\n" \ ALTINSTR_ENTRY_CB(cpucap, cb) \ ".popsection\n" \ "663:\n\t" \ @@ -102,13 +111,15 @@ .macro alternative_insn insn1, insn2, cap, enable = 1 .if \enable 661: \insn1 -662: .pushsection .altinstructions, "a" +662: .pushsection .altinstructions, "aM", @progbits, ALT_INSTR_SIZE altinstruction_entry 661b, 663f, \cap, 662b-661b, 664f-663f .popsection .subsection 1 + ANNOTATE_DATA_SPECIAL 663: \insn2 664: .org . - (664b-663b) + (662b-661b) .org . - (662b-661b) + (664b-663b) + ANNOTATE_DATA_SPECIAL_END .previous .endif .endm @@ -137,7 +148,7 @@ */ .macro alternative_if_not cap .set .Lasm_alt_mode, 0 - .pushsection .altinstructions, "a" + .pushsection .altinstructions, "aM", @progbits, ALT_INSTR_SIZE altinstruction_entry 661f, 663f, \cap, 662f-661f, 664f-663f .popsection 661: @@ -145,17 +156,18 @@ .macro alternative_if cap .set .Lasm_alt_mode, 1 - .pushsection .altinstructions, "a" + .pushsection .altinstructions, "aM", @progbits, ALT_INSTR_SIZE altinstruction_entry 663f, 661f, \cap, 664f-663f, 662f-661f .popsection .subsection 1 .align 2 /* So GAS knows label 661 is suitably aligned */ + ANNOTATE_DATA_SPECIAL 661: .endm .macro alternative_cb cap, cb .set .Lasm_alt_mode, 0 - .pushsection .altinstructions, "a" + .pushsection .altinstructions, "aM", @progbits, ALT_INSTR_SIZE altinstruction_entry 661f, \cb, (1 << ARM64_CB_SHIFT) | \cap, 662f-661f, 0 .popsection 661: @@ -168,7 +180,9 @@ 662: .if .Lasm_alt_mode==0 .subsection 1 + ANNOTATE_DATA_SPECIAL .else + ANNOTATE_DATA_SPECIAL_END .previous .endif 663: @@ -182,6 +196,7 @@ .org . - (664b-663b) + (662b-661b) .org . - (662b-661b) + (664b-663b) .if .Lasm_alt_mode==0 + ANNOTATE_DATA_SPECIAL_END .previous .endif .endm diff --git a/arch/arm64/include/asm/asm-bug.h b/arch/arm64/include/asm/asm-bug.h index a5f13801b7840..22e1a9df9851d 100644 --- a/arch/arm64/include/asm/asm-bug.h +++ b/arch/arm64/include/asm/asm-bug.h @@ -5,6 +5,7 @@ */ #define __ASM_ASM_BUG_H +#include <linux/annotate.h> #include <asm/brk-imm.h> #ifdef CONFIG_DEBUG_BUGVERBOSE @@ -24,6 +25,7 @@ #define __BUG_ENTRY_START \ .pushsection __bug_table,"aw"; \ .align 2; \ + __ANNOTATE_DATA_SPECIAL; \ 14470: .long 14471f - .; \ #define __BUG_ENTRY_END \ diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h index d67e2fdd1aee5..e81700edbb936 100644 --- a/arch/arm64/include/asm/asm-extable.h +++ b/arch/arm64/include/asm/asm-extable.h @@ -5,6 +5,10 @@ #include <linux/bits.h> #include <asm/gpr-num.h> +#ifndef COMPILE_OFFSETS +#include <asm/asm-offsets.h> +#endif + #define EX_TYPE_NONE 0 #define EX_TYPE_BPF 1 #define EX_TYPE_UACCESS_ERR_ZERO 2 @@ -29,13 +33,13 @@ #ifdef __ASSEMBLER__ -#define __ASM_EXTABLE_RAW(insn, fixup, type, data) \ - .pushsection __ex_table, "a"; \ - .align 2; \ - .long ((insn) - .); \ - .long ((fixup) - .); \ - .short (type); \ - .short (data); \ +#define __ASM_EXTABLE_RAW(insn, fixup, type, data) \ + .pushsection __ex_table, "aM", @progbits, EXTABLE_SIZE; \ + .align 2; \ + .long ((insn) - .); \ + .long ((fixup) - .); \ + .short (type); \ + .short (data); \ .popsection; #define EX_DATA_REG(reg, gpr) \ @@ -82,7 +86,8 @@ #include <linux/stringify.h> #define __ASM_EXTABLE_RAW(insn, fixup, type, data) \ - ".pushsection __ex_table, \"a\"\n" \ + ".pushsection __ex_table, \"aM\", @progbits, "\ + __stringify(EXTABLE_SIZE) "\n" \ ".align 2\n" \ ".long ((" insn ") - .)\n" \ ".long ((" fixup ") - .)\n" \ diff --git a/arch/arm64/include/asm/jump_label.h b/arch/arm64/include/asm/jump_label.h index 0cb211d3607d3..4dacb28641d72 100644 --- a/arch/arm64/include/asm/jump_label.h +++ b/arch/arm64/include/asm/jump_label.h @@ -11,6 +11,7 @@ #ifndef __ASSEMBLER__ #include <linux/types.h> +#include <linux/annotate.h> #include <asm/insn.h> #define HAVE_JUMP_LABEL_BATCH @@ -19,6 +20,7 @@ #define JUMP_TABLE_ENTRY(key, label) \ ".pushsection __jump_table, \"aw\"\n\t" \ ".align 3\n\t" \ + ANNOTATE_DATA_SPECIAL "\n\t" \ ".long 1b - ., " label " - .\n\t" \ ".quad " key " - .\n\t" \ ".popsection\n\t" diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 44b92f582c127..76251586e31c7 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -23,6 +23,8 @@ #include <asm/suspend.h> #include <linux/kbuild.h> #include <linux/arm-smccc.h> +#include <asm/alternative.h> +#include <asm/extable.h> int main(void) { @@ -185,5 +187,8 @@ int main(void) #endif DEFINE(PIE_E0_ASM, PIE_E0); DEFINE(PIE_E1_ASM, PIE_E1); + BLANK(); + DEFINE(ALT_INSTR_SIZE, sizeof(struct alt_instr)); + DEFINE(EXTABLE_SIZE, sizeof(struct exception_table_entry)); return 0; } diff --git a/include/linux/annotate.h b/include/linux/annotate.h index 2f1599c9e5732..7f5aa15f353d6 100644 --- a/include/linux/annotate.h +++ b/include/linux/annotate.h @@ -3,6 +3,7 @@ #define _LINUX_ANNOTATE_H #include <linux/objtool_types.h> +#include <linux/stringify.h> #ifdef CONFIG_OBJTOOL @@ -11,6 +12,10 @@ .long label - ., type; \ .popsection +#define __ASM_ANNOTATE_DATA(type) \ +912: \ + __ASM_ANNOTATE(.discard.annotate_data, 912b, type) + #ifndef __ASSEMBLY__ #define ASM_ANNOTATE_LABEL(label, type) \ @@ -39,6 +44,9 @@ #endif /* __ASSEMBLY__ */ #else /* !CONFIG_OBJTOOL */ + +#define __ASM_ANNOTATE_DATA(type) + #ifndef __ASSEMBLY__ #define ASM_ANNOTATE_LABEL(label, type) "" #define ASM_ANNOTATE(type) @@ -106,10 +114,12 @@ #define ANNOTATE_NOCFI_SYM(sym) asm(ASM_ANNOTATE_LABEL(sym, ANNOTYPE_NOCFI)) /* - * Annotate a special section entry. This emables livepatch module generation + * Annotate a special section entry. This enables livepatch module generation * to find and extract individual special section entries as needed. */ #define ANNOTATE_DATA_SPECIAL ASM_ANNOTATE_DATA(ANNOTYPE_DATA_SPECIAL) +#define __ANNOTATE_DATA_SPECIAL __ASM_ANNOTATE_DATA(ANNOTYPE_DATA_SPECIAL) +#define ANNOTATE_DATA_SPECIAL_END ASM_ANNOTATE_DATA(ANNOTYPE_DATA_SPECIAL_END) #else /* __ASSEMBLY__ */ #define ANNOTATE_NOENDBR ANNOTATE type=ANNOTYPE_NOENDBR @@ -122,6 +132,8 @@ #define ANNOTATE_REACHABLE ANNOTATE type=ANNOTYPE_REACHABLE #define ANNOTATE_NOCFI_SYM ANNOTATE type=ANNOTYPE_NOCFI #define ANNOTATE_DATA_SPECIAL ANNOTATE_DATA type=ANNOTYPE_DATA_SPECIAL +#define __ANNOTATE_DATA_SPECIAL __ASM_ANNOTATE_DATA(ANNOTYPE_DATA_SPECIAL) +#define ANNOTATE_DATA_SPECIAL_END ANNOTATE_DATA type=ANNOTYPE_DATA_SPECIAL_END #endif /* __ASSEMBLY__ */ #endif /* _LINUX_ANNOTATE_H */ diff --git a/include/linux/objtool_types.h b/include/linux/objtool_types.h index c6def4049b1ae..744118ffd025f 100644 --- a/include/linux/objtool_types.h +++ b/include/linux/objtool_types.h @@ -68,5 +68,6 @@ struct unwind_hint { #define ANNOTYPE_NOCFI 9 #define ANNOTYPE_DATA_SPECIAL 1 +#define ANNOTYPE_DATA_SPECIAL_END 2 #endif /* _LINUX_OBJTOOL_TYPES_H */ diff --git a/tools/include/linux/objtool_types.h b/tools/include/linux/objtool_types.h index c6def4049b1ae..744118ffd025f 100644 --- a/tools/include/linux/objtool_types.h +++ b/tools/include/linux/objtool_types.h @@ -68,5 +68,6 @@ struct unwind_hint { #define ANNOTYPE_NOCFI 9 #define ANNOTYPE_DATA_SPECIAL 1 +#define ANNOTYPE_DATA_SPECIAL_END 2 #endif /* _LINUX_OBJTOOL_TYPES_H */ diff --git a/tools/objtool/klp-diff.c b/tools/objtool/klp-diff.c index f8787d7d14547..6a1cec57dc6a3 100644 --- a/tools/objtool/klp-diff.c +++ b/tools/objtool/klp-diff.c @@ -1667,7 +1667,10 @@ static int create_fake_symbols(struct elf *elf) size = 0; next_reloc = reloc; for_each_reloc_continue(sec->rsec, next_reloc) { - if (annotype(elf, sec, next_reloc) != ANNOTYPE_DATA_SPECIAL || + unsigned int next_type = annotype(elf, sec, next_reloc); + + if ((next_type != ANNOTYPE_DATA_SPECIAL && + next_type != ANNOTYPE_DATA_SPECIAL_END) || next_reloc->sym->sec != reloc->sym->sec) continue; -- 2.53.0
