1 files changed, 157 insertions, 322 deletions

diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c
index 2a5b338b2542..43a0361a8bf0 100644
--- a/arch/arm64/kernel/probes/kprobes.c
+++ b/arch/arm64/kernel/probes/kprobes.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * arch/arm64/kernel/probes/kprobes.c
  *
@@ -5,36 +6,33 @@
  *
  * Copyright (C) 2013 Linaro Limited.
  * Author: Sandeepa Prabhu <sandeepa.prabhu@linaro.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
  */
+
+#define pr_fmt(fmt) "kprobes: " fmt
+
+#include <linux/execmem.h>
+#include <linux/extable.h>
 #include <linux/kasan.h>
 #include <linux/kernel.h>
 #include <linux/kprobes.h>
-#include <linux/extable.h>
-#include <linux/slab.h>
-#include <linux/stop_machine.h>
 #include <linux/sched/debug.h>
 #include <linux/set_memory.h>
+#include <linux/slab.h>
+#include <linux/stop_machine.h>
 #include <linux/stringify.h>
+#include <linux/uaccess.h>
 #include <linux/vmalloc.h>
-#include <asm/traps.h>
-#include <asm/ptrace.h>
+
 #include <asm/cacheflush.h>
+#include <asm/daifflags.h>
 #include <asm/debug-monitors.h>
-#include <asm/system_misc.h>
 #include <asm/insn.h>
-#include <linux/uaccess.h>
 #include <asm/irq.h>
+#include <asm/text-patching.h>
+#include <asm/ptrace.h>
 #include <asm/sections.h>
+#include <asm/system_misc.h>
+#include <asm/traps.h>
 
 #include "decode-insn.h"
 
@@ -42,39 +40,59 @@ DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
 DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
 
 static void __kprobes
-post_kprobe_handler(struct kprobe_ctlblk *, struct pt_regs *);
+post_kprobe_handler(struct kprobe *, struct kprobe_ctlblk *, struct pt_regs *);
 
-static int __kprobes patch_text(kprobe_opcode_t *addr, u32 opcode)
+void *alloc_insn_page(void)
 {
-	void *addrs[1];
-	u32 insns[1];
-
-	addrs[0] = addr;
-	insns[0] = opcode;
-
-	return aarch64_insn_patch_text(addrs, insns, 1);
+	void *addr;
+
+	addr = execmem_alloc(EXECMEM_KPROBES, PAGE_SIZE);
+	if (!addr)
+		return NULL;
+	if (set_memory_rox((unsigned long)addr, 1)) {
+		execmem_free(addr);
+		return NULL;
+	}
+	return addr;
 }
 
 static void __kprobes arch_prepare_ss_slot(struct kprobe *p)
 {
-	/* prepare insn slot */
-	patch_text(p->ainsn.api.insn, p->opcode);
+	kprobe_opcode_t *addr = p->ainsn.xol_insn;
 
-	flush_icache_range((uintptr_t) (p->ainsn.api.insn),
-			   (uintptr_t) (p->ainsn.api.insn) +
-			   MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
+	/*
+	 * Prepare insn slot, Mark Rutland points out it depends on a coupe of
+	 * subtleties:
+	 *
+	 * - That the I-cache maintenance for these instructions is complete
+	 *   *before* the kprobe BRK is written (and aarch64_insn_patch_text_nosync()
+	 *   ensures this, but just omits causing a Context-Synchronization-Event
+	 *   on all CPUS).
+	 *
+	 * - That the kprobe BRK results in an exception (and consequently a
+	 *   Context-Synchronoization-Event), which ensures that the CPU will
+	 *   fetch thesingle-step slot instructions *after* this, ensuring that
+	 *   the new instructions are used
+	 *
+	 * It supposes to place ISB after patching to guarantee I-cache maintenance
+	 * is observed on all CPUS, however, single-step slot is installed in
+	 * the BRK exception handler, so it is unnecessary to generate
+	 * Contex-Synchronization-Event via ISB again.
+	 */
+	aarch64_insn_patch_text_nosync(addr, le32_to_cpu(p->opcode));
+	aarch64_insn_patch_text_nosync(addr + 1, BRK64_OPCODE_KPROBES_SS);
 
 	/*
 	 * Needs restoring of return address after stepping xol.
 	 */
-	p->ainsn.api.restore = (unsigned long) p->addr +
+	p->ainsn.xol_restore = (unsigned long) p->addr +
 	  sizeof(kprobe_opcode_t);
 }
 
 static void __kprobes arch_prepare_simulate(struct kprobe *p)
 {
 	/* This instructions is not executed xol. No need to adjust the PC */
-	p->ainsn.api.restore = 0;
+	p->ainsn.xol_restore = 0;
 }
 
 static void __kprobes arch_simulate_insn(struct kprobe *p, struct pt_regs *regs)
@@ -82,28 +100,23 @@ static void __kprobes arch_simulate_insn(struct kprobe *p, struct pt_regs *regs)
 	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
 
 	if (p->ainsn.api.handler)
-		p->ainsn.api.handler((u32)p->opcode, (long)p->addr, regs);
+		p->ainsn.api.handler(le32_to_cpu(p->opcode), (long)p->addr, regs);
 
 	/* single step simulated, now go for post processing */
-	post_kprobe_handler(kcb, regs);
+	post_kprobe_handler(p, kcb, regs);
 }
 
 int __kprobes arch_prepare_kprobe(struct kprobe *p)
 {
 	unsigned long probe_addr = (unsigned long)p->addr;
-	extern char __start_rodata[];
-	extern char __end_rodata[];
 
 	if (probe_addr & 0x3)
 		return -EINVAL;
 
 	/* copy instruction */
-	p->opcode = le32_to_cpu(*p->addr);
+	p->opcode = *p->addr;
 
-	if (in_exception_text(probe_addr))
-		return -EINVAL;
-	if (probe_addr >= (unsigned long) __start_rodata &&
-	    probe_addr <= (unsigned long) __end_rodata)
+	if (search_exception_tables(probe_addr))
 		return -EINVAL;
 
 	/* decode instruction */
@@ -112,18 +125,18 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
 		return -EINVAL;
 
 	case INSN_GOOD_NO_SLOT:	/* insn need simulation */
-		p->ainsn.api.insn = NULL;
+		p->ainsn.xol_insn = NULL;
 		break;
 
 	case INSN_GOOD:	/* instruction uses slot */
-		p->ainsn.api.insn = get_insn_slot();
-		if (!p->ainsn.api.insn)
+		p->ainsn.xol_insn = get_insn_slot();
+		if (!p->ainsn.xol_insn)
 			return -ENOMEM;
 		break;
 	}
 
 	/* prepare the instruction */
-	if (p->ainsn.api.insn)
+	if (p->ainsn.xol_insn)
 		arch_prepare_ss_slot(p);
 	else
 		arch_prepare_simulate(p);
@@ -131,34 +144,29 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
 	return 0;
 }
 
-void *alloc_insn_page(void)
-{
-	void *page;
-
-	page = vmalloc_exec(PAGE_SIZE);
-	if (page)
-		set_memory_ro((unsigned long)page, 1);
-
-	return page;
-}
-
 /* arm kprobe: install breakpoint in text */
 void __kprobes arch_arm_kprobe(struct kprobe *p)
 {
-	patch_text(p->addr, BRK64_OPCODE_KPROBES);
+	void *addr = p->addr;
+	u32 insn = BRK64_OPCODE_KPROBES;
+
+	aarch64_insn_patch_text(&addr, &insn, 1);
 }
 
 /* disarm kprobe: remove breakpoint from text */
 void __kprobes arch_disarm_kprobe(struct kprobe *p)
 {
-	patch_text(p->addr, p->opcode);
+	void *addr = p->addr;
+	u32 insn = le32_to_cpu(p->opcode);
+
+	aarch64_insn_patch_text(&addr, &insn, 1);
 }
 
 void __kprobes arch_remove_kprobe(struct kprobe *p)
 {
-	if (p->ainsn.api.insn) {
-		free_insn_slot(p->ainsn.api.insn, 0);
-		p->ainsn.api.insn = NULL;
+	if (p->ainsn.xol_insn) {
+		free_insn_slot(p->ainsn.xol_insn, 0);
+		p->ainsn.xol_insn = NULL;
 	}
 }
 
@@ -180,67 +188,22 @@ static void __kprobes set_current_kprobe(struct kprobe *p)
 }
 
 /*
- * When PSTATE.D is set (masked), then software step exceptions can not be
- * generated.
- * SPSR's D bit shows the value of PSTATE.D immediately before the
- * exception was taken. PSTATE.D is set while entering into any exception
- * mode, however software clears it for any normal (none-debug-exception)
- * mode in the exception entry. Therefore, when we are entering into kprobe
- * breakpoint handler from any normal mode then SPSR.D bit is already
- * cleared, however it is set when we are entering from any debug exception
- * mode.
- * Since we always need to generate single step exception after a kprobe
- * breakpoint exception therefore we need to clear it unconditionally, when
- * we become sure that the current breakpoint exception is for kprobe.
- */
-static void __kprobes
-spsr_set_debug_flag(struct pt_regs *regs, int mask)
-{
-	unsigned long spsr = regs->pstate;
-
-	if (mask)
-		spsr |= PSR_D_BIT;
-	else
-		spsr &= ~PSR_D_BIT;
-
-	regs->pstate = spsr;
-}
-
-/*
- * Interrupts need to be disabled before single-step mode is set, and not
- * reenabled until after single-step mode ends.
- * Without disabling interrupt on local CPU, there is a chance of
- * interrupt occurrence in the period of exception return and  start of
- * out-of-line single-step, that result in wrongly single stepping
- * into the interrupt handler.
+ * Mask all of DAIF while executing the instruction out-of-line, to keep things
+ * simple and avoid nesting exceptions. Interrupts do have to be disabled since
+ * the kprobe state is per-CPU and doesn't get migrated.
  */
 static void __kprobes kprobes_save_local_irqflag(struct kprobe_ctlblk *kcb,
 						struct pt_regs *regs)
 {
-	kcb->saved_irqflag = regs->pstate;
-	regs->pstate |= PSR_I_BIT;
+	kcb->saved_irqflag = regs->pstate & DAIF_MASK;
+	regs->pstate |= DAIF_MASK;
 }
 
 static void __kprobes kprobes_restore_local_irqflag(struct kprobe_ctlblk *kcb,
 						struct pt_regs *regs)
 {
-	if (kcb->saved_irqflag & PSR_I_BIT)
-		regs->pstate |= PSR_I_BIT;
-	else
-		regs->pstate &= ~PSR_I_BIT;
-}
-
-static void __kprobes
-set_ss_context(struct kprobe_ctlblk *kcb, unsigned long addr)
-{
-	kcb->ss_ctx.ss_pending = true;
-	kcb->ss_ctx.match_addr = addr + sizeof(kprobe_opcode_t);
-}
-
-static void __kprobes clear_ss_context(struct kprobe_ctlblk *kcb)
-{
-	kcb->ss_ctx.ss_pending = false;
-	kcb->ss_ctx.match_addr = 0;
+	regs->pstate &= ~DAIF_MASK;
+	regs->pstate |= kcb->saved_irqflag;
 }
 
 static void __kprobes setup_singlestep(struct kprobe *p,
@@ -258,17 +221,11 @@ static void __kprobes setup_singlestep(struct kprobe *p,
 	}
 
 
-	if (p->ainsn.api.insn) {
+	if (p->ainsn.xol_insn) {
 		/* prepare for single stepping */
-		slot = (unsigned long)p->ainsn.api.insn;
-
-		set_ss_context(kcb, slot);	/* mark pending ss */
+		slot = (unsigned long)p->ainsn.xol_insn;
 
-		spsr_set_debug_flag(regs, 0);
-
-		/* IRQs and single stepping do not mix well. */
 		kprobes_save_local_irqflag(kcb, regs);
-		kernel_enable_single_step(regs);
 		instruction_pointer_set(regs, slot);
 	} else {
 		/* insn simulation */
@@ -288,7 +245,7 @@ static int __kprobes reenter_kprobe(struct kprobe *p,
 		break;
 	case KPROBE_HIT_SS:
 	case KPROBE_REENTER:
-		pr_warn("Unrecoverable kprobe detected.\n");
+		pr_warn("Failed to recover from reentered kprobes.\n");
 		dump_kprobe(p);
 		BUG();
 		break;
@@ -301,16 +258,11 @@ static int __kprobes reenter_kprobe(struct kprobe *p,
 }
 
 static void __kprobes
-post_kprobe_handler(struct kprobe_ctlblk *kcb, struct pt_regs *regs)
+post_kprobe_handler(struct kprobe *cur, struct kprobe_ctlblk *kcb, struct pt_regs *regs)
 {
-	struct kprobe *cur = kprobe_running();
-
-	if (!cur)
-		return;
-
 	/* return addr restore if non-branching insn */
-	if (cur->ainsn.api.restore != 0)
-		instruction_pointer_set(regs, cur->ainsn.api.restore);
+	if (cur->ainsn.xol_restore != 0)
+		instruction_pointer_set(regs, cur->ainsn.xol_restore);
 
 	/* restore back original saved kprobe variables and continue */
 	if (kcb->kprobe_status == KPROBE_REENTER) {
@@ -319,12 +271,8 @@ post_kprobe_handler(struct kprobe_ctlblk *kcb, struct pt_regs *regs)
 	}
 	/* call post handler */
 	kcb->kprobe_status = KPROBE_HIT_SSDONE;
-	if (cur->post_handler)	{
-		/* post_handler can hit breakpoint and single step
-		 * again, so we enable D-flag for recursive exception.
-		 */
+	if (cur->post_handler)
 		cur->post_handler(cur, regs, 0);
-	}
 
 	reset_current_kprobe();
 }
@@ -345,47 +293,22 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, unsigned int fsr)
 		 * normal page fault.
 		 */
 		instruction_pointer_set(regs, (unsigned long) cur->addr);
-		if (!instruction_pointer(regs))
-			BUG();
-
-		kernel_disable_single_step();
+		BUG_ON(!instruction_pointer(regs));
 
-		if (kcb->kprobe_status == KPROBE_REENTER)
+		if (kcb->kprobe_status == KPROBE_REENTER) {
 			restore_previous_kprobe(kcb);
-		else
+		} else {
+			kprobes_restore_local_irqflag(kcb, regs);
 			reset_current_kprobe();
+		}
 
 		break;
-	case KPROBE_HIT_ACTIVE:
-	case KPROBE_HIT_SSDONE:
-		/*
-		 * We increment the nmissed count for accounting,
-		 * we can also use npre/npostfault count for accounting
-		 * these specific fault cases.
-		 */
-		kprobes_inc_nmissed_count(cur);
-
-		/*
-		 * We come here because instructions in the pre/post
-		 * handler caused the page_fault, this could happen
-		 * if handler tries to access user space by
-		 * copy_from_user(), get_user() etc. Let the
-		 * user-specified handler try to fix it first.
-		 */
-		if (cur->fault_handler && cur->fault_handler(cur, regs, fsr))
-			return 1;
-
-		/*
-		 * In case the user-specified fault handler returned
-		 * zero, try to fix up.
-		 */
-		if (fixup_exception(regs))
-			return 1;
 	}
 	return 0;
 }
 
-static void __kprobes kprobe_handler(struct pt_regs *regs)
+int __kprobes
+kprobe_brk_handler(struct pt_regs *regs, unsigned long esr)
 {
 	struct kprobe *p, *cur_kprobe;
 	struct kprobe_ctlblk *kcb;
@@ -395,189 +318,101 @@ static void __kprobes kprobe_handler(struct pt_regs *regs)
 	cur_kprobe = kprobe_running();
 
 	p = get_kprobe((kprobe_opcode_t *) addr);
-
-	if (p) {
-		if (cur_kprobe) {
-			if (reenter_kprobe(p, regs, kcb))
-				return;
-		} else {
-			/* Probe hit */
-			set_current_kprobe(p);
-			kcb->kprobe_status = KPROBE_HIT_ACTIVE;
-
-			/*
-			 * If we have no pre-handler or it returned 0, we
-			 * continue with normal processing.  If we have a
-			 * pre-handler and it returned non-zero, it will
-			 * modify the execution path and no need to single
-			 * stepping. Let's just reset current kprobe and exit.
-			 *
-			 * pre_handler can hit a breakpoint and can step thru
-			 * before return, keep PSTATE D-flag enabled until
-			 * pre_handler return back.
-			 */
-			if (!p->pre_handler || !p->pre_handler(p, regs)) {
-				setup_singlestep(p, regs, kcb, 0);
-			} else
-				reset_current_kprobe();
-		}
+	if (WARN_ON_ONCE(!p)) {
+		/*
+		 * Something went wrong. This BRK used an immediate reserved
+		 * for kprobes, but we couldn't find any corresponding probe.
+		 */
+		return DBG_HOOK_ERROR;
 	}
-	/*
-	 * The breakpoint instruction was removed right
-	 * after we hit it.  Another cpu has removed
-	 * either a probepoint or a debugger breakpoint
-	 * at this address.  In either case, no further
-	 * handling of this interrupt is appropriate.
-	 * Return back to original instruction, and continue.
-	 */
-}
 
-static int __kprobes
-kprobe_ss_hit(struct kprobe_ctlblk *kcb, unsigned long addr)
-{
-	if ((kcb->ss_ctx.ss_pending)
-	    && (kcb->ss_ctx.match_addr == addr)) {
-		clear_ss_context(kcb);	/* clear pending ss */
-		return DBG_HOOK_HANDLED;
+	if (cur_kprobe) {
+		/* Hit a kprobe inside another kprobe */
+		if (!reenter_kprobe(p, regs, kcb))
+			return DBG_HOOK_ERROR;
+	} else {
+		/* Probe hit */
+		set_current_kprobe(p);
+		kcb->kprobe_status = KPROBE_HIT_ACTIVE;
+
+		/*
+		 * If we have no pre-handler or it returned 0, we
+		 * continue with normal processing.  If we have a
+		 * pre-handler and it returned non-zero, it will
+		 * modify the execution path and not need to single-step
+		 * Let's just reset current kprobe and exit.
+		 */
+		if (!p->pre_handler || !p->pre_handler(p, regs))
+			setup_singlestep(p, regs, kcb, 0);
+		else
+			reset_current_kprobe();
 	}
-	/* not ours, kprobes should ignore it */
-	return DBG_HOOK_ERROR;
+
+	return DBG_HOOK_HANDLED;
 }
 
 int __kprobes
-kprobe_single_step_handler(struct pt_regs *regs, unsigned int esr)
+kprobe_ss_brk_handler(struct pt_regs *regs, unsigned long esr)
 {
 	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-	int retval;
-
-	/* return error if this is not our step */
-	retval = kprobe_ss_hit(kcb, instruction_pointer(regs));
+	unsigned long addr = instruction_pointer(regs);
+	struct kprobe *cur = kprobe_running();
 
-	if (retval == DBG_HOOK_HANDLED) {
+	if (cur && (kcb->kprobe_status & (KPROBE_HIT_SS | KPROBE_REENTER)) &&
+	    ((unsigned long)&cur->ainsn.xol_insn[1] == addr)) {
 		kprobes_restore_local_irqflag(kcb, regs);
-		kernel_disable_single_step();
+		post_kprobe_handler(cur, kcb, regs);
 
-		post_kprobe_handler(kcb, regs);
+		return DBG_HOOK_HANDLED;
 	}
 
-	return retval;
+	/* not ours, kprobes should ignore it */
+	return DBG_HOOK_ERROR;
 }
 
 int __kprobes
-kprobe_breakpoint_handler(struct pt_regs *regs, unsigned int esr)
-{
-	kprobe_handler(regs);
-	return DBG_HOOK_HANDLED;
-}
-
-bool arch_within_kprobe_blacklist(unsigned long addr)
+kretprobe_brk_handler(struct pt_regs *regs, unsigned long esr)
 {
-	if ((addr >= (unsigned long)__kprobes_text_start &&
-	    addr < (unsigned long)__kprobes_text_end) ||
-	    (addr >= (unsigned long)__entry_text_start &&
-	    addr < (unsigned long)__entry_text_end) ||
-	    (addr >= (unsigned long)__idmap_text_start &&
-	    addr < (unsigned long)__idmap_text_end) ||
-	    !!search_exception_tables(addr))
-		return true;
-
-	if (!is_kernel_in_hyp_mode()) {
-		if ((addr >= (unsigned long)__hyp_text_start &&
-		    addr < (unsigned long)__hyp_text_end) ||
-		    (addr >= (unsigned long)__hyp_idmap_text_start &&
-		    addr < (unsigned long)__hyp_idmap_text_end))
-			return true;
-	}
+	if (regs->pc != (unsigned long)__kretprobe_trampoline)
+		return DBG_HOOK_ERROR;
 
-	return false;
+	regs->pc = kretprobe_trampoline_handler(regs, (void *)regs->regs[29]);
+	return DBG_HOOK_HANDLED;
 }
 
-void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs)
+/*
+ * Provide a blacklist of symbols identifying ranges which cannot be kprobed.
+ * This blacklist is exposed to userspace via debugfs (kprobes/blacklist).
+ */
+int __init arch_populate_kprobe_blacklist(void)
 {
-	struct kretprobe_instance *ri = NULL;
-	struct hlist_head *head, empty_rp;
-	struct hlist_node *tmp;
-	unsigned long flags, orig_ret_address = 0;
-	unsigned long trampoline_address =
-		(unsigned long)&kretprobe_trampoline;
-	kprobe_opcode_t *correct_ret_addr = NULL;
-
-	INIT_HLIST_HEAD(&empty_rp);
-	kretprobe_hash_lock(current, &head, &flags);
-
-	/*
-	 * It is possible to have multiple instances associated with a given
-	 * task either because multiple functions in the call path have
-	 * return probes installed on them, and/or more than one
-	 * return probe was registered for a target function.
-	 *
-	 * We can handle this because:
-	 *     - instances are always pushed into the head of the list
-	 *     - when multiple return probes are registered for the same
-	 *	 function, the (chronologically) first instance's ret_addr
-	 *	 will be the real return address, and all the rest will
-	 *	 point to kretprobe_trampoline.
-	 */
-	hlist_for_each_entry_safe(ri, tmp, head, hlist) {
-		if (ri->task != current)
-			/* another task is sharing our hash bucket */
-			continue;
-
-		orig_ret_address = (unsigned long)ri->ret_addr;
-
-		if (orig_ret_address != trampoline_address)
-			/*
-			 * This is the real return address. Any other
-			 * instances associated with this task are for
-			 * other calls deeper on the call stack
-			 */
-			break;
-	}
-
-	kretprobe_assert(ri, orig_ret_address, trampoline_address);
-
-	correct_ret_addr = ri->ret_addr;
-	hlist_for_each_entry_safe(ri, tmp, head, hlist) {
-		if (ri->task != current)
-			/* another task is sharing our hash bucket */
-			continue;
-
-		orig_ret_address = (unsigned long)ri->ret_addr;
-		if (ri->rp && ri->rp->handler) {
-			__this_cpu_write(current_kprobe, &ri->rp->kp);
-			get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
-			ri->ret_addr = correct_ret_addr;
-			ri->rp->handler(ri, regs);
-			__this_cpu_write(current_kprobe, NULL);
-		}
-
-		recycle_rp_inst(ri, &empty_rp);
-
-		if (orig_ret_address != trampoline_address)
-			/*
-			 * This is the real return address. Any other
-			 * instances associated with this task are for
-			 * other calls deeper on the call stack
-			 */
-			break;
-	}
-
-	kretprobe_hash_unlock(current, &flags);
-
-	hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
-		hlist_del(&ri->hlist);
-		kfree(ri);
-	}
-	return (void *)orig_ret_address;
+	int ret;
+
+	ret = kprobe_add_area_blacklist((unsigned long)__entry_text_start,
+					(unsigned long)__entry_text_end);
+	if (ret)
+		return ret;
+	ret = kprobe_add_area_blacklist((unsigned long)__irqentry_text_start,
+					(unsigned long)__irqentry_text_end);
+	if (ret)
+		return ret;
+	ret = kprobe_add_area_blacklist((unsigned long)__hyp_text_start,
+					(unsigned long)__hyp_text_end);
+	if (ret || is_kernel_in_hyp_mode())
+		return ret;
+	ret = kprobe_add_area_blacklist((unsigned long)__hyp_idmap_text_start,
+					(unsigned long)__hyp_idmap_text_end);
+	return ret;
 }
 
 void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
 				      struct pt_regs *regs)
 {
 	ri->ret_addr = (kprobe_opcode_t *)regs->regs[30];
+	ri->fp = (void *)regs->regs[29];
 
 	/* replace return addr (x30) with trampoline */
-	regs->regs[30] = (long)&kretprobe_trampoline;
+	regs->regs[30] = (long)&__kretprobe_trampoline;
 }
 
 int __kprobes arch_trampoline_kprobe(struct kprobe *p)