Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * Kernel probes (kprobes) for SuperH
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Copyright (C) 2007 Chris Smith <chris.smith@st.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  * Copyright (C) 2006 Lineo Solutions, Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <linux/kprobes.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <linux/extable.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <linux/ptrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <linux/preempt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/kdebug.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <asm/cacheflush.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) static DEFINE_PER_CPU(struct kprobe, saved_current_opcode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) static DEFINE_PER_CPU(struct kprobe, saved_next_opcode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) static DEFINE_PER_CPU(struct kprobe, saved_next_opcode2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) #define OPCODE_JMP(x)	(((x) & 0xF0FF) == 0x402b)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) #define OPCODE_JSR(x)	(((x) & 0xF0FF) == 0x400b)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) #define OPCODE_BRA(x)	(((x) & 0xF000) == 0xa000)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) #define OPCODE_BRAF(x)	(((x) & 0xF0FF) == 0x0023)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) #define OPCODE_BSR(x)	(((x) & 0xF000) == 0xb000)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) #define OPCODE_BSRF(x)	(((x) & 0xF0FF) == 0x0003)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) #define OPCODE_BF_S(x)	(((x) & 0xFF00) == 0x8f00)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) #define OPCODE_BT_S(x)	(((x) & 0xFF00) == 0x8d00)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) #define OPCODE_BF(x)	(((x) & 0xFF00) == 0x8b00)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) #define OPCODE_BT(x)	(((x) & 0xFF00) == 0x8900)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) #define OPCODE_RTS(x)	(((x) & 0x000F) == 0x000b)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) #define OPCODE_RTE(x)	(((x) & 0xFFFF) == 0x002b)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) int __kprobes arch_prepare_kprobe(struct kprobe *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	kprobe_opcode_t opcode = *(kprobe_opcode_t *) (p->addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	if (OPCODE_RTE(opcode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 		return -EFAULT;	/* Bad breakpoint */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 	p->opcode = opcode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) void __kprobes arch_copy_kprobe(struct kprobe *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	p->opcode = *p->addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) void __kprobes arch_arm_kprobe(struct kprobe *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	*p->addr = BREAKPOINT_INSTRUCTION;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	flush_icache_range((unsigned long)p->addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 			   (unsigned long)p->addr + sizeof(kprobe_opcode_t));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) void __kprobes arch_disarm_kprobe(struct kprobe *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	*p->addr = p->opcode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	flush_icache_range((unsigned long)p->addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 			   (unsigned long)p->addr + sizeof(kprobe_opcode_t));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) int __kprobes arch_trampoline_kprobe(struct kprobe *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	if (*p->addr == BREAKPOINT_INSTRUCTION)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 		return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81)  * If an illegal slot instruction exception occurs for an address
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82)  * containing a kprobe, remove the probe.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84)  * Returns 0 if the exception was handled successfully, 1 otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) int __kprobes kprobe_handle_illslot(unsigned long pc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	struct kprobe *p = get_kprobe((kprobe_opcode_t *) pc + 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	if (p != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 		printk("Warning: removing kprobe from delay slot: 0x%.8x\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 		       (unsigned int)pc + 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 		unregister_kprobe(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) void __kprobes arch_remove_kprobe(struct kprobe *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	struct kprobe *saved = this_cpu_ptr(&saved_next_opcode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	if (saved->addr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 		arch_disarm_kprobe(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 		arch_disarm_kprobe(saved);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 		saved->addr = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 		saved->opcode = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 		saved = this_cpu_ptr(&saved_next_opcode2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 		if (saved->addr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 			arch_disarm_kprobe(saved);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 			saved->addr = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 			saved->opcode = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 		}
^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) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	kcb->prev_kprobe.kp = kprobe_running();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	kcb->prev_kprobe.status = kcb->kprobe_status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	kcb->kprobe_status = kcb->prev_kprobe.status;
^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) static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 					 struct kprobe_ctlblk *kcb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	__this_cpu_write(current_kprobe, p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)  * Singlestep is implemented by disabling the current kprobe and setting one
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)  * on the next instruction, following branches. Two probes are set if the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)  * branch is conditional.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	__this_cpu_write(saved_current_opcode.addr, (kprobe_opcode_t *)regs->pc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	if (p != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 		struct kprobe *op1, *op2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 		arch_disarm_kprobe(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 		op1 = this_cpu_ptr(&saved_next_opcode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 		op2 = this_cpu_ptr(&saved_next_opcode2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 		if (OPCODE_JSR(p->opcode) || OPCODE_JMP(p->opcode)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 			unsigned int reg_nr = ((p->opcode >> 8) & 0x000F);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 			op1->addr = (kprobe_opcode_t *) regs->regs[reg_nr];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 		} else if (OPCODE_BRA(p->opcode) || OPCODE_BSR(p->opcode)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 			unsigned long disp = (p->opcode & 0x0FFF);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 			op1->addr =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 			    (kprobe_opcode_t *) (regs->pc + 4 + disp * 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 		} else if (OPCODE_BRAF(p->opcode) || OPCODE_BSRF(p->opcode)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 			unsigned int reg_nr = ((p->opcode >> 8) & 0x000F);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 			op1->addr =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 			    (kprobe_opcode_t *) (regs->pc + 4 +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 						 regs->regs[reg_nr]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 		} else if (OPCODE_RTS(p->opcode)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 			op1->addr = (kprobe_opcode_t *) regs->pr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		} else if (OPCODE_BF(p->opcode) || OPCODE_BT(p->opcode)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 			unsigned long disp = (p->opcode & 0x00FF);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 			/* case 1 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 			op1->addr = p->addr + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 			/* case 2 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 			op2->addr =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 			    (kprobe_opcode_t *) (regs->pc + 4 + disp * 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 			op2->opcode = *(op2->addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 			arch_arm_kprobe(op2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 		} else if (OPCODE_BF_S(p->opcode) || OPCODE_BT_S(p->opcode)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 			unsigned long disp = (p->opcode & 0x00FF);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 			/* case 1 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 			op1->addr = p->addr + 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 			/* case 2 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 			op2->addr =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 			    (kprobe_opcode_t *) (regs->pc + 4 + disp * 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 			op2->opcode = *(op2->addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 			arch_arm_kprobe(op2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 		} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 			op1->addr = p->addr + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 		op1->opcode = *(op1->addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 		arch_arm_kprobe(op1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) /* Called with kretprobe_lock held */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 				      struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	ri->ret_addr = (kprobe_opcode_t *) regs->pr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 	ri->fp = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 	/* Replace the return addr with trampoline addr */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 	regs->pr = (unsigned long)kretprobe_trampoline;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) static int __kprobes kprobe_handler(struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	struct kprobe *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	kprobe_opcode_t *addr = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 	struct kprobe_ctlblk *kcb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 	 * We don't want to be preempted for the entire
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 	 * duration of kprobe processing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 	preempt_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 	kcb = get_kprobe_ctlblk();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 	addr = (kprobe_opcode_t *) (regs->pc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 	/* Check we're not actually recursing */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 	if (kprobe_running()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 		p = get_kprobe(addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 		if (p) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 			if (kcb->kprobe_status == KPROBE_HIT_SS &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 			    *p->ainsn.insn == BREAKPOINT_INSTRUCTION) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 				goto no_kprobe;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 			/* We have reentered the kprobe_handler(), since
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 			 * another probe was hit while within the handler.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 			 * We here save the original kprobes variables and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 			 * just single step on the instruction of the new probe
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 			 * without calling any user handlers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 			 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 			save_previous_kprobe(kcb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 			set_current_kprobe(p, regs, kcb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 			kprobes_inc_nmissed_count(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 			prepare_singlestep(p, regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 			kcb->kprobe_status = KPROBE_REENTER;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 			return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 		goto no_kprobe;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 	p = get_kprobe(addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 	if (!p) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 		/* Not one of ours: let kernel handle it */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 		if (*(kprobe_opcode_t *)addr != BREAKPOINT_INSTRUCTION) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 			/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 			 * The breakpoint instruction was removed right
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 			 * after we hit it. Another cpu has removed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 			 * either a probepoint or a debugger breakpoint
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 			 * at this address. In either case, no further
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 			 * handling of this interrupt is appropriate.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 			 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 			ret = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 		goto no_kprobe;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 	set_current_kprobe(p, regs, kcb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 	kcb->kprobe_status = KPROBE_HIT_ACTIVE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 	if (p->pre_handler && p->pre_handler(p, regs)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 		/* handler has already set things up, so skip ss setup */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 		reset_current_kprobe();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 		preempt_enable_no_resched();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 		return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 	prepare_singlestep(p, regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	kcb->kprobe_status = KPROBE_HIT_SS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 	return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) no_kprobe:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 	preempt_enable_no_resched();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290)  * For function-return probes, init_kprobes() establishes a probepoint
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291)  * here. When a retprobed function returns, this probe is hit and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292)  * trampoline_probe_handler() runs, calling the kretprobe's handler.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) static void __used kretprobe_trampoline_holder(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 	asm volatile (".globl kretprobe_trampoline\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 		      "kretprobe_trampoline:\n\t"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 		      "nop\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302)  * Called when we hit the probe point at kretprobe_trampoline
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 	regs->pc = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 	return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) static int __kprobes post_kprobe_handler(struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 	struct kprobe *cur = kprobe_running();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) 	kprobe_opcode_t *addr = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) 	struct kprobe *p = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) 	if (!cur)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 	if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 		kcb->kprobe_status = KPROBE_HIT_SSDONE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) 		cur->post_handler(cur, regs, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) 	p = this_cpu_ptr(&saved_next_opcode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) 	if (p->addr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) 		arch_disarm_kprobe(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) 		p->addr = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) 		p->opcode = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) 		addr = __this_cpu_read(saved_current_opcode.addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) 		__this_cpu_write(saved_current_opcode.addr, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) 		p = get_kprobe(addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) 		arch_arm_kprobe(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) 		p = this_cpu_ptr(&saved_next_opcode2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) 		if (p->addr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) 			arch_disarm_kprobe(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) 			p->addr = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) 			p->opcode = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) 	/* Restore back the original saved kprobes variables and continue. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) 	if (kcb->kprobe_status == KPROBE_REENTER) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) 		restore_previous_kprobe(kcb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) 	reset_current_kprobe();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) 	preempt_enable_no_resched();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) 	return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) 	struct kprobe *cur = kprobe_running();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) 	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) 	const struct exception_table_entry *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) 	switch (kcb->kprobe_status) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) 	case KPROBE_HIT_SS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) 	case KPROBE_REENTER:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) 		 * We are here because the instruction being single
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) 		 * stepped caused a page fault. We reset the current
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) 		 * kprobe, point the pc back to the probe address
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) 		 * and allow the page fault handler to continue as a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) 		 * normal page fault.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) 		regs->pc = (unsigned long)cur->addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) 		if (kcb->kprobe_status == KPROBE_REENTER)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) 			restore_previous_kprobe(kcb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) 		else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) 			reset_current_kprobe();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) 		preempt_enable_no_resched();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) 	case KPROBE_HIT_ACTIVE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) 	case KPROBE_HIT_SSDONE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) 		 * We increment the nmissed count for accounting,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) 		 * we can also use npre/npostfault count for accounting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) 		 * these specific fault cases.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) 		kprobes_inc_nmissed_count(cur);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) 		 * We come here because instructions in the pre/post
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) 		 * handler caused the page_fault, this could happen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) 		 * if handler tries to access user space by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) 		 * copy_from_user(), get_user() etc. Let the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) 		 * user-specified handler try to fix it first.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) 		if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) 			return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) 		 * In case the user-specified fault handler returned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) 		 * zero, try to fix up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) 		if ((entry = search_exception_tables(regs->pc)) != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) 			regs->pc = entry->fixup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) 			return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) 		 * fixup_exception() could not handle it,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) 		 * Let do_page_fault() fix it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424)  * Wrapper routine to for handling exceptions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) 				       unsigned long val, void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) 	struct kprobe *p = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) 	struct die_args *args = (struct die_args *)data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) 	int ret = NOTIFY_DONE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) 	kprobe_opcode_t *addr = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) 	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) 	addr = (kprobe_opcode_t *) (args->regs->pc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) 	if (val == DIE_TRAP &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) 	    args->trapnr == (BREAKPOINT_INSTRUCTION & 0xff)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) 		if (!kprobe_running()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) 			if (kprobe_handler(args->regs)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) 				ret = NOTIFY_STOP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) 			} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) 				/* Not a kprobe trap */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) 				ret = NOTIFY_DONE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) 		} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) 			p = get_kprobe(addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) 			if ((kcb->kprobe_status == KPROBE_HIT_SS) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) 			    (kcb->kprobe_status == KPROBE_REENTER)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) 				if (post_kprobe_handler(args->regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) 					ret = NOTIFY_STOP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) 			} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) 				if (kprobe_handler(args->regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) 					ret = NOTIFY_STOP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) static struct kprobe trampoline_p = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) 	.addr = (kprobe_opcode_t *)&kretprobe_trampoline,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) 	.pre_handler = trampoline_probe_handler
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) int __init arch_init_kprobes(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) 	return register_kprobe(&trampoline_p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) }