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linux
objtool: Add ANNOTATE_DATA_SPECIAL
In preparation for the objtool klp diff subcommand, add an
ANNOTATE_DATA_SPECIAL macro which annotates special section entries so
that objtool can determine their size and location and extract them
when needed.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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include/linux/annotate.h
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include/linux/annotate.h
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#ifndef __ASSEMBLY__
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#define __ASM_ANNOTATE(label, type) \
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".pushsection .discard.annotate_insn,\"M\",@progbits,8\n\t" \
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#define __ASM_ANNOTATE(section, label, type) \
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".pushsection " section ",\"M\", @progbits, 8\n\t" \
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".long " __stringify(label) " - .\n\t" \
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".long " __stringify(type) "\n\t" \
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".popsection\n\t"
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#define ASM_ANNOTATE_LABEL(label, type) \
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__ASM_ANNOTATE(".discard.annotate_insn", label, type)
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#define ASM_ANNOTATE(type) \
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"911:\n\t" \
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__ASM_ANNOTATE(911b, type)
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ASM_ANNOTATE_LABEL(911b, type)
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#define ASM_ANNOTATE_DATA(type) \
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"912:\n\t" \
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__ASM_ANNOTATE(".discard.annotate_data", 912b, type)
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#else /* __ASSEMBLY__ */
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.macro ANNOTATE type:req
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.macro __ANNOTATE section, type
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.Lhere_\@:
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.pushsection .discard.annotate_insn,"M",@progbits,8
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.pushsection \section, "M", @progbits, 8
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.long .Lhere_\@ - .
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.long \type
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.popsection
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.endm
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.macro ANNOTATE type
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__ANNOTATE ".discard.annotate_insn", \type
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.endm
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.macro ANNOTATE_DATA type
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__ANNOTATE ".discard.annotate_data", \type
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.endm
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#endif /* __ASSEMBLY__ */
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#else /* !CONFIG_OBJTOOL */
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#ifndef __ASSEMBLY__
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#define __ASM_ANNOTATE(label, type) ""
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#define ASM_ANNOTATE_LABEL(label, type) ""
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#define ASM_ANNOTATE(type)
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#define ASM_ANNOTATE_DATA(type)
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#else /* __ASSEMBLY__ */
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.macro ANNOTATE type:req
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.macro ANNOTATE type
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.endm
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.macro ANNOTATE_DATA type
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.endm
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#endif /* __ASSEMBLY__ */
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#endif /* !CONFIG_OBJTOOL */
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* these relocations will never be used for indirect calls.
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*/
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#define ANNOTATE_NOENDBR ASM_ANNOTATE(ANNOTYPE_NOENDBR)
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#define ANNOTATE_NOENDBR_SYM(sym) asm(__ASM_ANNOTATE(sym, ANNOTYPE_NOENDBR))
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#define ANNOTATE_NOENDBR_SYM(sym) asm(ASM_ANNOTATE_LABEL(sym, ANNOTYPE_NOENDBR))
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/*
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* This should be used immediately before an indirect jump/call. It tells
···
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/*
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* See linux/instrumentation.h
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*/
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#define ANNOTATE_INSTR_BEGIN(label) __ASM_ANNOTATE(label, ANNOTYPE_INSTR_BEGIN)
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#define ANNOTATE_INSTR_END(label) __ASM_ANNOTATE(label, ANNOTYPE_INSTR_END)
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#define ANNOTATE_INSTR_BEGIN(label) ASM_ANNOTATE_LABEL(label, ANNOTYPE_INSTR_BEGIN)
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#define ANNOTATE_INSTR_END(label) ASM_ANNOTATE_LABEL(label, ANNOTYPE_INSTR_END)
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/*
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* objtool annotation to ignore the alternatives and only consider the original
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* instruction(s).
···
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* terminating, like a noreturn CALL or UD2 when we know they are not -- eg
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* WARN using UD2.
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*/
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#define ANNOTATE_REACHABLE(label) __ASM_ANNOTATE(label, ANNOTYPE_REACHABLE)
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#define ANNOTATE_REACHABLE(label) ASM_ANNOTATE_LABEL(label, ANNOTYPE_REACHABLE)
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/*
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* This should not be used; it annotates away CFI violations. There are a few
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* valid use cases like kexec handover to the next kernel image, and there is
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* There are also a few real issues annotated away, like EFI because we can't
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* control the EFI code.
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*/
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#define ANNOTATE_NOCFI_SYM(sym) asm(__ASM_ANNOTATE(sym, ANNOTYPE_NOCFI))
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#define ANNOTATE_NOCFI_SYM(sym) asm(ASM_ANNOTATE_LABEL(sym, ANNOTYPE_NOCFI))
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/*
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* Annotate a special section entry. This emables livepatch module generation
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* to find and extract individual special section entries as needed.
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*/
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#define ANNOTATE_DATA_SPECIAL ASM_ANNOTATE_DATA(ANNOTYPE_DATA_SPECIAL)
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#else /* __ASSEMBLY__ */
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#define ANNOTATE_NOENDBR ANNOTATE type=ANNOTYPE_NOENDBR
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#define ANNOTATE_UNRET_BEGIN ANNOTATE type=ANNOTYPE_UNRET_BEGIN
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#define ANNOTATE_REACHABLE ANNOTATE type=ANNOTYPE_REACHABLE
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#define ANNOTATE_NOCFI_SYM ANNOTATE type=ANNOTYPE_NOCFI
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#define ANNOTATE_DATA_SPECIAL ANNOTATE_DATA type=ANNOTYPE_DATA_SPECIAL
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#endif /* __ASSEMBLY__ */
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#endif /* _LINUX_ANNOTATE_H */
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include/linux/objtool_types.h
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include/linux/objtool_types.h