// SPDX-License-Identifier: GPL-2.0#include <linux/kernel.h>#include <linux/spinlock.h>#include <linux/kprobes.h>#include <linux/mm.h>#include <linux/stop_machine.h> #include <asm/cacheflush.h>#include <asm/fixmap.h>#include <asm/smp_plat.h>#include <asm/opcodes.h>#include <asm/patch.h> struct patch {	void *addr;	unsigned int insn;}; static DEFINE_SPINLOCK(patch_lock); static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags)	__acquires(&patch_lock){	unsigned int uintaddr = (uintptr_t) addr;	bool module = !core_kernel_text(uintaddr);	struct page *page; 	if (module && IS_ENABLED(CONFIG_STRICT_MODULE_RWX))		page = vmalloc_to_page(addr);	else if (!module && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))		page = virt_to_page(addr);	else		return addr; 	if (flags)		spin_lock_irqsave(&patch_lock, *flags);	else		__acquire(&patch_lock); 	set_fixmap(fixmap, page_to_phys(page)); 	return (void *) (__fix_to_virt(fixmap) + (uintaddr & ~PAGE_MASK));} static void __kprobes patch_unmap(int fixmap, unsigned long *flags)	__releases(&patch_lock){	clear_fixmap(fixmap); 	if (flags)		spin_unlock_irqrestore(&patch_lock, *flags);	else		__release(&patch_lock);} void __kprobes __patch_text_real(void *addr, unsigned int insn, bool remap){	bool thumb2 = IS_ENABLED(CONFIG_THUMB2_KERNEL);	unsigned int uintaddr = (uintptr_t) addr;	bool twopage = false;	unsigned long flags;	void *waddr = addr;	int size; 	if (remap)		waddr = patch_map(addr, FIX_TEXT_POKE0, &flags);	else		__acquire(&patch_lock); 	if (thumb2 && __opcode_is_thumb16(insn)) {		*(u16 *)waddr = __opcode_to_mem_thumb16(insn);		size = sizeof(u16);	} else if (thumb2 && (uintaddr & 2)) {		u16 first = __opcode_thumb32_first(insn);		u16 second = __opcode_thumb32_second(insn);		u16 *addrh0 = waddr;		u16 *addrh1 = waddr + 2; 		twopage = (uintaddr & ~PAGE_MASK) == PAGE_SIZE - 2;		if (twopage && remap)			addrh1 = patch_map(addr + 2, FIX_TEXT_POKE1, NULL); 		*addrh0 = __opcode_to_mem_thumb16(first);		*addrh1 = __opcode_to_mem_thumb16(second); 		if (twopage && addrh1 != addr + 2) {			flush_kernel_vmap_range(addrh1, 2);			patch_unmap(FIX_TEXT_POKE1, NULL);		} 		size = sizeof(u32);	} else {		if (thumb2)			insn = __opcode_to_mem_thumb32(insn);		else			insn = __opcode_to_mem_arm(insn); 		*(u32 *)waddr = insn;		size = sizeof(u32);	} 	if (waddr != addr) {		flush_kernel_vmap_range(waddr, twopage ? size / 2 : size);		patch_unmap(FIX_TEXT_POKE0, &flags);	} else		__release(&patch_lock); 	flush_icache_range((uintptr_t)(addr),			   (uintptr_t)(addr) + size);} static int __kprobes patch_text_stop_machine(void *data){	struct patch *patch = data; 	__patch_text(patch->addr, patch->insn); 	return 0;} void __kprobes patch_text(void *addr, unsigned int insn){	struct patch patch = {		.addr = addr,		.insn = insn,	}; 	stop_machine_cpuslocked(patch_text_stop_machine, &patch, NULL);}