1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/spinlock.h>
4 #include <linux/kprobes.h>
6 #include <linux/stop_machine.h>
8 #include <asm/cacheflush.h>
9 #include <asm/fixmap.h>
10 #include <asm/smp_plat.h>
11 #include <asm/opcodes.h>
12 #include <asm/patch.h>
20 static DEFINE_RAW_SPINLOCK(patch_lock);
22 static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags)
24 unsigned int uintaddr = (uintptr_t) addr;
25 bool module = !core_kernel_text(uintaddr);
28 if (module && IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
29 page = vmalloc_to_page(addr);
30 else if (!module && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
31 page = virt_to_page(addr);
36 raw_spin_lock_irqsave(&patch_lock, *flags);
38 set_fixmap(fixmap, page_to_phys(page));
40 return (void *) (__fix_to_virt(fixmap) + (uintaddr & ~PAGE_MASK));
43 static void __kprobes patch_unmap(int fixmap, unsigned long *flags)
48 raw_spin_unlock_irqrestore(&patch_lock, *flags);
51 static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags)
55 static void __kprobes patch_unmap(int fixmap, unsigned long *flags) { }
58 void __kprobes __patch_text_real(void *addr, unsigned int insn, bool remap)
60 bool thumb2 = IS_ENABLED(CONFIG_THUMB2_KERNEL);
61 unsigned int uintaddr = (uintptr_t) addr;
68 waddr = patch_map(addr, FIX_TEXT_POKE0, &flags);
70 if (thumb2 && __opcode_is_thumb16(insn)) {
71 *(u16 *)waddr = __opcode_to_mem_thumb16(insn);
73 } else if (thumb2 && (uintaddr & 2)) {
74 u16 first = __opcode_thumb32_first(insn);
75 u16 second = __opcode_thumb32_second(insn);
77 u16 *addrh1 = waddr + 2;
79 twopage = (uintaddr & ~PAGE_MASK) == PAGE_SIZE - 2;
81 addrh1 = patch_map(addr + 2, FIX_TEXT_POKE1, NULL);
83 *addrh0 = __opcode_to_mem_thumb16(first);
84 *addrh1 = __opcode_to_mem_thumb16(second);
86 if (twopage && addrh1 != addr + 2) {
87 flush_kernel_vmap_range(addrh1, 2);
88 patch_unmap(FIX_TEXT_POKE1, NULL);
94 insn = __opcode_to_mem_thumb32(insn);
96 insn = __opcode_to_mem_arm(insn);
103 flush_kernel_vmap_range(waddr, twopage ? size / 2 : size);
104 patch_unmap(FIX_TEXT_POKE0, &flags);
107 flush_icache_range((uintptr_t)(addr),
108 (uintptr_t)(addr) + size);
111 static int __kprobes patch_text_stop_machine(void *data)
113 struct patch *patch = data;
115 __patch_text(patch->addr, patch->insn);
120 void __kprobes patch_text(void *addr, unsigned int insn)
122 struct patch patch = {
127 stop_machine_cpuslocked(patch_text_stop_machine, &patch, NULL);