73 lines
2.3 KiB
C
73 lines
2.3 KiB
C
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/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_X86_TEXT_PATCHING_H
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#define _ASM_X86_TEXT_PATCHING_H
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#include <linux/types.h>
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#include <linux/stddef.h>
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#include <asm/ptrace.h>
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struct paravirt_patch_site;
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#ifdef CONFIG_PARAVIRT
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void apply_paravirt(struct paravirt_patch_site *start,
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struct paravirt_patch_site *end);
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#else
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static inline void apply_paravirt(struct paravirt_patch_site *start,
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struct paravirt_patch_site *end)
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{}
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#define __parainstructions NULL
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#define __parainstructions_end NULL
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#endif
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extern void *text_poke_early(void *addr, const void *opcode, size_t len);
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/*
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* Clear and restore the kernel write-protection flag on the local CPU.
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* Allows the kernel to edit read-only pages.
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* Side-effect: any interrupt handler running between save and restore will have
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* the ability to write to read-only pages.
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*
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* Warning:
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* Code patching in the UP case is safe if NMIs and MCE handlers are stopped and
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* no thread can be preempted in the instructions being modified (no iret to an
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* invalid instruction possible) or if the instructions are changed from a
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* consistent state to another consistent state atomically.
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* On the local CPU you need to be protected again NMI or MCE handlers seeing an
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* inconsistent instruction while you patch.
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*/
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extern void *text_poke(void *addr, const void *opcode, size_t len);
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extern int poke_int3_handler(struct pt_regs *regs);
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extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler);
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extern int after_bootmem;
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#ifndef CONFIG_UML_X86
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static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip)
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{
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regs->ip = ip;
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}
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#define INT3_INSN_SIZE 1
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#define CALL_INSN_SIZE 5
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#ifdef CONFIG_X86_64
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static inline void int3_emulate_push(struct pt_regs *regs, unsigned long val)
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{
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/*
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* The int3 handler in entry_64.S adds a gap between the
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* stack where the break point happened, and the saving of
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* pt_regs. We can extend the original stack because of
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* this gap. See the idtentry macro's create_gap option.
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*/
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regs->sp -= sizeof(unsigned long);
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*(unsigned long *)regs->sp = val;
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}
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static inline void int3_emulate_call(struct pt_regs *regs, unsigned long func)
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{
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int3_emulate_push(regs, regs->ip - INT3_INSN_SIZE + CALL_INSN_SIZE);
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int3_emulate_jmp(regs, func);
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}
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#endif /* CONFIG_X86_64 */
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#endif /* !CONFIG_UML_X86 */
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#endif /* _ASM_X86_TEXT_PATCHING_H */
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