Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * Copyright (C) 2014-2016 Pratyush Anand <panand@redhat.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) #include <linux/highmem.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) #include <linux/ptrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) #include <linux/uprobes.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <asm/cacheflush.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include "decode-insn.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #define UPROBE_INV_FAULT_CODE	UINT_MAX
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) 		void *src, unsigned long len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) 	void *xol_page_kaddr = kmap_atomic(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) 	void *dst = xol_page_kaddr + (vaddr & ~PAGE_MASK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) 	/* Initialize the slot */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) 	memcpy(dst, src, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 	/* flush caches (dcache/icache) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 	sync_icache_aliases(dst, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 	kunmap_atomic(xol_page_kaddr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) unsigned long uprobe_get_swbp_addr(struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 	return instruction_pointer(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 		unsigned long addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	probe_opcode_t insn;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 	/* TODO: Currently we do not support AARCH32 instruction probing */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	if (mm->context.flags & MMCF_AARCH32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 		return -EOPNOTSUPP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	else if (!IS_ALIGNED(addr, AARCH64_INSN_SIZE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	insn = *(probe_opcode_t *)(&auprobe->insn[0]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 	switch (arm_probe_decode_insn(insn, &auprobe->api)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 	case INSN_REJECTED:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	case INSN_GOOD_NO_SLOT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 		auprobe->simulate = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	struct uprobe_task *utask = current->utask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	/* Initialize with an invalid fault code to detect if ol insn trapped */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	current->thread.fault_code = UPROBE_INV_FAULT_CODE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	/* Instruction points to execute ol */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	instruction_pointer_set(regs, utask->xol_vaddr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	user_enable_single_step(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	struct uprobe_task *utask = current->utask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	WARN_ON_ONCE(current->thread.fault_code != UPROBE_INV_FAULT_CODE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	/* Instruction points to execute next to breakpoint address */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	instruction_pointer_set(regs, utask->vaddr + 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	user_disable_single_step(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) bool arch_uprobe_xol_was_trapped(struct task_struct *t)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 	 * Between arch_uprobe_pre_xol and arch_uprobe_post_xol, if an xol
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	 * insn itself is trapped, then detect the case with the help of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 	 * invalid fault code which is being set in arch_uprobe_pre_xol
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	if (t->thread.fault_code != UPROBE_INV_FAULT_CODE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 		return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	probe_opcode_t insn;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	unsigned long addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	if (!auprobe->simulate)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 		return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	insn = *(probe_opcode_t *)(&auprobe->insn[0]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	addr = instruction_pointer(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	if (auprobe->api.handler)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 		auprobe->api.handler(insn, addr, regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	struct uprobe_task *utask = current->utask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	 * Task has received a fatal signal, so reset back to probbed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	 * address.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	instruction_pointer_set(regs, utask->vaddr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	user_disable_single_step(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) bool arch_uretprobe_is_alive(struct return_instance *ret, enum rp_check ctx,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 		struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	 * If a simple branch instruction (B) was called for retprobed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	 * assembly label then return true even when regs->sp and ret->stack
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	 * are same. It will ensure that cleanup and reporting of return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	 * instances corresponding to callee label is done when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	 * handle_trampoline for called function is executed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	if (ctx == RP_CHECK_CHAIN_CALL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 		return regs->sp <= ret->stack;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 		return regs->sp < ret->stack;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) unsigned long
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 				  struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	unsigned long orig_ret_vaddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	orig_ret_vaddr = procedure_link_pointer(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	/* Replace the return addr with trampoline addr */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	procedure_link_pointer_set(regs, trampoline_vaddr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	return orig_ret_vaddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) int arch_uprobe_exception_notify(struct notifier_block *self,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 				 unsigned long val, void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	return NOTIFY_DONE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) static int uprobe_breakpoint_handler(struct pt_regs *regs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 		unsigned int esr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	if (uprobe_pre_sstep_notifier(regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 		return DBG_HOOK_HANDLED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	return DBG_HOOK_ERROR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) static int uprobe_single_step_handler(struct pt_regs *regs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 		unsigned int esr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 	struct uprobe_task *utask = current->utask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	WARN_ON(utask && (instruction_pointer(regs) != utask->xol_vaddr + 4));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 	if (uprobe_post_sstep_notifier(regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 		return DBG_HOOK_HANDLED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 	return DBG_HOOK_ERROR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) /* uprobe breakpoint handler hook */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) static struct break_hook uprobes_break_hook = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	.imm = UPROBES_BRK_IMM,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	.fn = uprobe_breakpoint_handler,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) /* uprobe single step handler hook */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) static struct step_hook uprobes_step_hook = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 	.fn = uprobe_single_step_handler,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) static int __init arch_init_uprobes(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	register_user_break_hook(&uprobes_break_hook);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	register_user_step_hook(&uprobes_step_hook);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) device_initcall(arch_init_uprobes);