1b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */ 235de5b06SAndy Lutomirski #ifndef _ASM_X86_TEXT_PATCHING_H 335de5b06SAndy Lutomirski #define _ASM_X86_TEXT_PATCHING_H 435de5b06SAndy Lutomirski 535de5b06SAndy Lutomirski #include <linux/types.h> 635de5b06SAndy Lutomirski #include <linux/stddef.h> 735de5b06SAndy Lutomirski #include <asm/ptrace.h> 835de5b06SAndy Lutomirski 935de5b06SAndy Lutomirski struct paravirt_patch_site; 1035de5b06SAndy Lutomirski #ifdef CONFIG_PARAVIRT 1135de5b06SAndy Lutomirski void apply_paravirt(struct paravirt_patch_site *start, 1235de5b06SAndy Lutomirski struct paravirt_patch_site *end); 1335de5b06SAndy Lutomirski #else 1435de5b06SAndy Lutomirski static inline void apply_paravirt(struct paravirt_patch_site *start, 1535de5b06SAndy Lutomirski struct paravirt_patch_site *end) 1635de5b06SAndy Lutomirski {} 1735de5b06SAndy Lutomirski #define __parainstructions NULL 1835de5b06SAndy Lutomirski #define __parainstructions_end NULL 1935de5b06SAndy Lutomirski #endif 2035de5b06SAndy Lutomirski 2135de5b06SAndy Lutomirski extern void *text_poke_early(void *addr, const void *opcode, size_t len); 2235de5b06SAndy Lutomirski 2335de5b06SAndy Lutomirski /* 2435de5b06SAndy Lutomirski * Clear and restore the kernel write-protection flag on the local CPU. 2535de5b06SAndy Lutomirski * Allows the kernel to edit read-only pages. 2635de5b06SAndy Lutomirski * Side-effect: any interrupt handler running between save and restore will have 2735de5b06SAndy Lutomirski * the ability to write to read-only pages. 2835de5b06SAndy Lutomirski * 2935de5b06SAndy Lutomirski * Warning: 3035de5b06SAndy Lutomirski * Code patching in the UP case is safe if NMIs and MCE handlers are stopped and 3135de5b06SAndy Lutomirski * no thread can be preempted in the instructions being modified (no iret to an 3235de5b06SAndy Lutomirski * invalid instruction possible) or if the instructions are changed from a 3335de5b06SAndy Lutomirski * consistent state to another consistent state atomically. 3435de5b06SAndy Lutomirski * On the local CPU you need to be protected again NMI or MCE handlers seeing an 3535de5b06SAndy Lutomirski * inconsistent instruction while you patch. 3635de5b06SAndy Lutomirski */ 3735de5b06SAndy Lutomirski extern void *text_poke(void *addr, const void *opcode, size_t len); 38*e836673cSNadav Amit extern void *text_poke_kgdb(void *addr, const void *opcode, size_t len); 3935de5b06SAndy Lutomirski extern int poke_int3_handler(struct pt_regs *regs); 4035de5b06SAndy Lutomirski extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler); 416fffacb3SPavel Tatashin extern int after_bootmem; 4235de5b06SAndy Lutomirski 4335de5b06SAndy Lutomirski #endif /* _ASM_X86_TEXT_PATCHING_H */ 44