1 files changed, 126 insertions, 376 deletions

diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c
index 6842e4501e2e..c450120b4474 100644
--- a/arch/s390/kernel/kprobes.c
+++ b/arch/s390/kernel/kprobes.c
@@ -1,29 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  *  Kernel Probes (KProbes)
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- *
  * Copyright IBM Corp. 2002, 2006
  *
  * s390 port, used ppc64 as template. Mike Grundy <grundym@us.ibm.com>
  */
 
+#define pr_fmt(fmt) "kprobes: " fmt
+
 #include <linux/kprobes.h>
 #include <linux/ptrace.h>
 #include <linux/preempt.h>
 #include <linux/stop_machine.h>
+#include <linux/cpufeature.h>
 #include <linux/kdebug.h>
 #include <linux/uaccess.h>
 #include <linux/extable.h>
@@ -31,129 +21,118 @@
 #include <linux/slab.h>
 #include <linux/hardirq.h>
 #include <linux/ftrace.h>
+#include <linux/execmem.h>
+#include <asm/text-patching.h>
 #include <asm/set_memory.h>
 #include <asm/sections.h>
-#include <linux/uaccess.h>
 #include <asm/dis.h>
+#include "entry.h"
 
 DEFINE_PER_CPU(struct kprobe *, current_kprobe);
 DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
 
 struct kretprobe_blackpoint kretprobe_blacklist[] = { };
 
-DEFINE_INSN_CACHE_OPS(dmainsn);
-
-static void *alloc_dmainsn_page(void)
+void *alloc_insn_page(void)
 {
 	void *page;
 
-	page = (void *) __get_free_page(GFP_KERNEL | GFP_DMA);
-	if (page)
-		set_memory_x((unsigned long) page, 1);
+	page = execmem_alloc(EXECMEM_KPROBES, PAGE_SIZE);
+	if (!page)
+		return NULL;
+	set_memory_rox((unsigned long)page, 1);
 	return page;
 }
 
-static void free_dmainsn_page(void *page)
-{
-	set_memory_nx((unsigned long) page, 1);
-	free_page((unsigned long)page);
-}
-
-struct kprobe_insn_cache kprobe_dmainsn_slots = {
-	.mutex = __MUTEX_INITIALIZER(kprobe_dmainsn_slots.mutex),
-	.alloc = alloc_dmainsn_page,
-	.free = free_dmainsn_page,
-	.pages = LIST_HEAD_INIT(kprobe_dmainsn_slots.pages),
-	.insn_size = MAX_INSN_SIZE,
-};
-
 static void copy_instruction(struct kprobe *p)
 {
-	unsigned long ip = (unsigned long) p->addr;
+	kprobe_opcode_t insn[MAX_INSN_SIZE];
 	s64 disp, new_disp;
 	u64 addr, new_addr;
+	unsigned int len;
 
-	if (ftrace_location(ip) == ip) {
+	len = insn_length(*p->addr >> 8);
+	memcpy(&insn, p->addr, len);
+	p->opcode = insn[0];
+	if (probe_is_insn_relative_long(&insn[0])) {
 		/*
-		 * If kprobes patches the instruction that is morphed by
-		 * ftrace make sure that kprobes always sees the branch
-		 * "jg .+24" that skips the mcount block or the "brcl 0,0"
-		 * in case of hotpatch.
+		 * For pc-relative instructions in RIL-b or RIL-c format patch
+		 * the RI2 displacement field. The insn slot for the to be
+		 * patched instruction is within the same 4GB area like the
+		 * original instruction. Therefore the new displacement will
+		 * always fit.
 		 */
-		ftrace_generate_nop_insn((struct ftrace_insn *)p->ainsn.insn);
-		p->ainsn.is_ftrace_insn = 1;
-	} else
-		memcpy(p->ainsn.insn, p->addr, insn_length(*p->addr >> 8));
-	p->opcode = p->ainsn.insn[0];
-	if (!probe_is_insn_relative_long(p->ainsn.insn))
-		return;
-	/*
-	 * For pc-relative instructions in RIL-b or RIL-c format patch the
-	 * RI2 displacement field. We have already made sure that the insn
-	 * slot for the patched instruction is within the same 2GB area
-	 * as the original instruction (either kernel image or module area).
-	 * Therefore the new displacement will always fit.
-	 */
-	disp = *(s32 *)&p->ainsn.insn[1];
-	addr = (u64)(unsigned long)p->addr;
-	new_addr = (u64)(unsigned long)p->ainsn.insn;
-	new_disp = ((addr + (disp * 2)) - new_addr) / 2;
-	*(s32 *)&p->ainsn.insn[1] = new_disp;
+		disp = *(s32 *)&insn[1];
+		addr = (u64)(unsigned long)p->addr;
+		new_addr = (u64)(unsigned long)p->ainsn.insn;
+		new_disp = ((addr + (disp * 2)) - new_addr) / 2;
+		*(s32 *)&insn[1] = new_disp;
+	}
+	s390_kernel_write(p->ainsn.insn, &insn, len);
 }
 NOKPROBE_SYMBOL(copy_instruction);
 
-static inline int is_kernel_addr(void *addr)
-{
-	return addr < (void *)_end;
-}
-
-static int s390_get_insn_slot(struct kprobe *p)
+/* Check if paddr is at an instruction boundary */
+static bool can_probe(unsigned long paddr)
 {
-	/*
-	 * Get an insn slot that is within the same 2GB area like the original
-	 * instruction. That way instructions with a 32bit signed displacement
-	 * field can be patched and executed within the insn slot.
-	 */
-	p->ainsn.insn = NULL;
-	if (is_kernel_addr(p->addr))
-		p->ainsn.insn = get_dmainsn_slot();
-	else if (is_module_addr(p->addr))
-		p->ainsn.insn = get_insn_slot();
-	return p->ainsn.insn ? 0 : -ENOMEM;
-}
-NOKPROBE_SYMBOL(s390_get_insn_slot);
-
-static void s390_free_insn_slot(struct kprobe *p)
-{
-	if (!p->ainsn.insn)
-		return;
-	if (is_kernel_addr(p->addr))
-		free_dmainsn_slot(p->ainsn.insn, 0);
-	else
-		free_insn_slot(p->ainsn.insn, 0);
-	p->ainsn.insn = NULL;
+	unsigned long addr, offset = 0;
+	kprobe_opcode_t insn;
+	struct kprobe *kp;
+
+	if (paddr & 0x01)
+		return false;
+
+	if (!kallsyms_lookup_size_offset(paddr, NULL, &offset))
+		return false;
+
+	/* Decode instructions */
+	addr = paddr - offset;
+	while (addr < paddr) {
+		if (copy_from_kernel_nofault(&insn, (void *)addr, sizeof(insn)))
+			return false;
+
+		if (insn >> 8 == 0) {
+			if (insn != BREAKPOINT_INSTRUCTION) {
+				/*
+				 * Note that QEMU inserts opcode 0x0000 to implement
+				 * software breakpoints for guests. Since the size of
+				 * the original instruction is unknown, stop following
+				 * instructions and prevent setting a kprobe.
+				 */
+				return false;
+			}
+			/*
+			 * Check if the instruction has been modified by another
+			 * kprobe, in which case the original instruction is
+			 * decoded.
+			 */
+			kp = get_kprobe((void *)addr);
+			if (!kp) {
+				/* not a kprobe */
+				return false;
+			}
+			insn = kp->opcode;
+		}
+		addr += insn_length(insn >> 8);
+	}
+	return addr == paddr;
 }
-NOKPROBE_SYMBOL(s390_free_insn_slot);
 
 int arch_prepare_kprobe(struct kprobe *p)
 {
-	if ((unsigned long) p->addr & 0x01)
+	if (!can_probe((unsigned long)p->addr))
 		return -EINVAL;
 	/* Make sure the probe isn't going on a difficult instruction */
 	if (probe_is_prohibited_opcode(p->addr))
 		return -EINVAL;
-	if (s390_get_insn_slot(p))
+	p->ainsn.insn = get_insn_slot();
+	if (!p->ainsn.insn)
 		return -ENOMEM;
 	copy_instruction(p);
 	return 0;
 }
 NOKPROBE_SYMBOL(arch_prepare_kprobe);
 
-int arch_check_ftrace_location(struct kprobe *p)
-{
-	return 0;
-}
-
 struct swap_insn_args {
 	struct kprobe *p;
 	unsigned int arm_kprobe : 1;
@@ -161,33 +140,12 @@ struct swap_insn_args {
 
 static int swap_instruction(void *data)
 {
-	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-	unsigned long status = kcb->kprobe_status;
 	struct swap_insn_args *args = data;
-	struct ftrace_insn new_insn, *insn;
 	struct kprobe *p = args->p;
-	size_t len;
-
-	new_insn.opc = args->arm_kprobe ? BREAKPOINT_INSTRUCTION : p->opcode;
-	len = sizeof(new_insn.opc);
-	if (!p->ainsn.is_ftrace_insn)
-		goto skip_ftrace;
-	len = sizeof(new_insn);
-	insn = (struct ftrace_insn *) p->addr;
-	if (args->arm_kprobe) {
-		if (is_ftrace_nop(insn))
-			new_insn.disp = KPROBE_ON_FTRACE_NOP;
-		else
-			new_insn.disp = KPROBE_ON_FTRACE_CALL;
-	} else {
-		ftrace_generate_call_insn(&new_insn, (unsigned long)p->addr);
-		if (insn->disp == KPROBE_ON_FTRACE_NOP)
-			ftrace_generate_nop_insn(&new_insn);
-	}
-skip_ftrace:
-	kcb->kprobe_status = KPROBE_SWAP_INST;
-	s390_kernel_write(p->addr, &new_insn, len);
-	kcb->kprobe_status = status;
+	u16 opc;
+
+	opc = args->arm_kprobe ? BREAKPOINT_INSTRUCTION : p->opcode;
+	s390_kernel_write(p->addr, &opc, sizeof(opc));
 	return 0;
 }
 NOKPROBE_SYMBOL(swap_instruction);
@@ -196,7 +154,12 @@ void arch_arm_kprobe(struct kprobe *p)
 {
 	struct swap_insn_args args = {.p = p, .arm_kprobe = 1};
 
-	stop_machine_cpuslocked(swap_instruction, &args, NULL);
+	if (cpu_has_seq_insn()) {
+		swap_instruction(&args);
+		text_poke_sync();
+	} else {
+		stop_machine_cpuslocked(swap_instruction, &args, NULL);
+	}
 }
 NOKPROBE_SYMBOL(arch_arm_kprobe);
 
@@ -204,13 +167,21 @@ void arch_disarm_kprobe(struct kprobe *p)
 {
 	struct swap_insn_args args = {.p = p, .arm_kprobe = 0};
 
-	stop_machine_cpuslocked(swap_instruction, &args, NULL);
+	if (cpu_has_seq_insn()) {
+		swap_instruction(&args);
+		text_poke_sync();
+	} else {
+		stop_machine_cpuslocked(swap_instruction, &args, NULL);
+	}
 }
 NOKPROBE_SYMBOL(arch_disarm_kprobe);
 
 void arch_remove_kprobe(struct kprobe *p)
 {
-	s390_free_insn_slot(p);
+	if (!p->ainsn.insn)
+		return;
+	free_insn_slot(p->ainsn.insn, 0);
+	p->ainsn.insn = NULL;
 }
 NOKPROBE_SYMBOL(arch_remove_kprobe);
 
@@ -218,20 +189,27 @@ static void enable_singlestep(struct kprobe_ctlblk *kcb,
 			      struct pt_regs *regs,
 			      unsigned long ip)
 {
-	struct per_regs per_kprobe;
+	union {
+		struct ctlreg regs[3];
+		struct {
+			struct ctlreg control;
+			struct ctlreg start;
+			struct ctlreg end;
+		};
+	} per_kprobe;
 
 	/* Set up the PER control registers %cr9-%cr11 */
-	per_kprobe.control = PER_EVENT_IFETCH;
-	per_kprobe.start = ip;
-	per_kprobe.end = ip;
+	per_kprobe.control.val = PER_EVENT_IFETCH;
+	per_kprobe.start.val = ip;
+	per_kprobe.end.val = ip;
 
 	/* Save control regs and psw mask */
-	__ctl_store(kcb->kprobe_saved_ctl, 9, 11);
+	__local_ctl_store(9, 11, kcb->kprobe_saved_ctl);
 	kcb->kprobe_saved_imask = regs->psw.mask &
 		(PSW_MASK_PER | PSW_MASK_IO | PSW_MASK_EXT);
 
 	/* Set PER control regs, turns on single step for the given address */
-	__ctl_load(per_kprobe, 9, 11);
+	__local_ctl_load(9, 11, per_kprobe.regs);
 	regs->psw.mask |= PSW_MASK_PER;
 	regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT);
 	regs->psw.addr = ip;
@@ -243,7 +221,7 @@ static void disable_singlestep(struct kprobe_ctlblk *kcb,
 			       unsigned long ip)
 {
 	/* Restore control regs and psw mask, set new psw address */
-	__ctl_load(kcb->kprobe_saved_ctl, 9, 11);
+	__local_ctl_load(9, 11, kcb->kprobe_saved_ctl);
 	regs->psw.mask &= ~PSW_MASK_PER;
 	regs->psw.mask |= kcb->kprobe_saved_imask;
 	regs->psw.addr = ip;
@@ -272,18 +250,10 @@ static void pop_kprobe(struct kprobe_ctlblk *kcb)
 {
 	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
 	kcb->kprobe_status = kcb->prev_kprobe.status;
+	kcb->prev_kprobe.kp = NULL;
 }
 NOKPROBE_SYMBOL(pop_kprobe);
 
-void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs)
-{
-	ri->ret_addr = (kprobe_opcode_t *) regs->gprs[14];
-
-	/* Replace the return addr with trampoline addr */
-	regs->gprs[14] = (unsigned long) &kretprobe_trampoline;
-}
-NOKPROBE_SYMBOL(arch_prepare_kretprobe);
-
 static void kprobe_reenter_check(struct kprobe_ctlblk *kcb, struct kprobe *p)
 {
 	switch (kcb->kprobe_status) {
@@ -299,7 +269,7 @@ static void kprobe_reenter_check(struct kprobe_ctlblk *kcb, struct kprobe *p)
 		 * is a BUG. The code path resides in the .kprobes.text
 		 * section and is executed with interrupts disabled.
 		 */
-		printk(KERN_EMERG "Invalid kprobe detected at %p.\n", p->addr);
+		pr_err("Failed to recover from reentered kprobes.\n");
 		dump_kprobe(p);
 		BUG();
 	}
@@ -339,38 +309,20 @@ static int kprobe_handler(struct pt_regs *regs)
 			 * If we have no pre-handler or it returned 0, we
 			 * continue with single stepping. If we have a
 			 * pre-handler and it returned non-zero, it prepped
-			 * for calling the break_handler below on re-entry
-			 * for jprobe processing, so get out doing nothing
-			 * more here.
+			 * for changing execution path, so get out doing
+			 * nothing more here.
 			 */
 			push_kprobe(kcb, p);
 			kcb->kprobe_status = KPROBE_HIT_ACTIVE;
-			if (p->pre_handler && p->pre_handler(p, regs))
+			if (p->pre_handler && p->pre_handler(p, regs)) {
+				pop_kprobe(kcb);
+				preempt_enable_no_resched();
 				return 1;
+			}
 			kcb->kprobe_status = KPROBE_HIT_SS;
 		}
 		enable_singlestep(kcb, regs, (unsigned long) p->ainsn.insn);
 		return 1;
-	} else if (kprobe_running()) {
-		p = __this_cpu_read(current_kprobe);
-		if (p->break_handler && p->break_handler(p, regs)) {
-			/*
-			 * Continuation after the jprobe completed and
-			 * caused the jprobe_return trap. The jprobe
-			 * break_handler "returns" to the original
-			 * function that still has the kprobe breakpoint
-			 * installed. We continue with single stepping.
-			 */
-			kcb->kprobe_status = KPROBE_HIT_SS;
-			enable_singlestep(kcb, regs,
-					  (unsigned long) p->ainsn.insn);
-			return 1;
-		} /* else:
-		   * No kprobe at this address and the current kprobe
-		   * has no break handler (no jprobe!). The kernel just
-		   * exploded, let the standard trap handler pick up the
-		   * pieces.
-		   */
 	} /* else:
 	   * No kprobe at this address and no active kprobe. The trap has
 	   * not been caused by a kprobe breakpoint. The race of breakpoint
@@ -383,111 +335,6 @@ static int kprobe_handler(struct pt_regs *regs)
 NOKPROBE_SYMBOL(kprobe_handler);
 
 /*
- * Function return probe trampoline:
- *	- init_kprobes() establishes a probepoint here
- *	- When the probed function returns, this probe
- *		causes the handlers to fire
- */
-static void __used kretprobe_trampoline_holder(void)
-{
-	asm volatile(".global kretprobe_trampoline\n"
-		     "kretprobe_trampoline: bcr 0,0\n");
-}
-
-/*
- * Called when the probe at kretprobe trampoline is hit
- */
-static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
-{
-	struct kretprobe_instance *ri;
-	struct hlist_head *head, empty_rp;
-	struct hlist_node *tmp;
-	unsigned long flags, orig_ret_address;
-	unsigned long trampoline_address;
-	kprobe_opcode_t *correct_ret_addr;
-
-	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 an multiple functions in the call path
-	 * have a return probe installed on them, and/or more than one return
-	 * return probe was registered for a target function.
-	 *
-	 * We can handle this because:
-	 *     - instances are always inserted at the head of the list
-	 *     - when multiple return probes are registered for the same
-	 *	 function, the first instance's ret_addr will point to the
-	 *	 real return address, and all the rest will point to
-	 *	 kretprobe_trampoline
-	 */
-	ri = NULL;
-	orig_ret_address = 0;
-	correct_ret_addr = NULL;
-	trampoline_address = (unsigned long) &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) {
-			ri->ret_addr = correct_ret_addr;
-			ri->rp->handler(ri, regs);
-		}
-
-		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;
-	}
-
-	regs->psw.addr = orig_ret_address;
-
-	pop_kprobe(get_kprobe_ctlblk());
-	kretprobe_hash_unlock(current, &flags);
-	preempt_enable_no_resched();
-
-	hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
-		hlist_del(&ri->hlist);
-		kfree(ri);
-	}
-	/*
-	 * By returning a non-zero value, we are telling
-	 * kprobe_handler() that we don't want the post_handler
-	 * to run (and have re-enabled preemption)
-	 */
-	return 1;
-}
-NOKPROBE_SYMBOL(trampoline_probe_handler);
-
-/*
  * Called after single-stepping.  p->addr is the address of the
  * instruction whose first byte has been replaced by the "breakpoint"
  * instruction.  To avoid the SMP problems that can occur when we
@@ -501,24 +348,6 @@ static void resume_execution(struct kprobe *p, struct pt_regs *regs)
 	unsigned long ip = regs->psw.addr;
 	int fixup = probe_get_fixup_type(p->ainsn.insn);
 
-	/* Check if the kprobes location is an enabled ftrace caller */
-	if (p->ainsn.is_ftrace_insn) {
-		struct ftrace_insn *insn = (struct ftrace_insn *) p->addr;
-		struct ftrace_insn call_insn;
-
-		ftrace_generate_call_insn(&call_insn, (unsigned long) p->addr);
-		/*
-		 * A kprobe on an enabled ftrace call site actually single
-		 * stepped an unconditional branch (ftrace nop equivalent).
-		 * Now we need to fixup things and pretend that a brasl r0,...
-		 * was executed instead.
-		 */
-		if (insn->disp == KPROBE_ON_FTRACE_CALL) {
-			ip += call_insn.disp * 2 - MCOUNT_INSN_SIZE;
-			regs->gprs[0] = (unsigned long)p->addr + sizeof(*insn);
-		}
-	}
-
 	if (fixup & FIXUP_PSW_NORMAL)
 		ip += (unsigned long) p->addr - (unsigned long) p->ainsn.insn;
 
@@ -546,12 +375,11 @@ static int post_kprobe_handler(struct pt_regs *regs)
 	if (!p)
 		return 0;
 
+	resume_execution(p, regs);
 	if (kcb->kprobe_status != KPROBE_REENTER && p->post_handler) {
 		kcb->kprobe_status = KPROBE_HIT_SSDONE;
 		p->post_handler(p, regs, 0);
 	}
-
-	resume_execution(p, regs);
 	pop_kprobe(kcb);
 	preempt_enable_no_resched();
 
@@ -571,12 +399,8 @@ static int kprobe_trap_handler(struct pt_regs *regs, int trapnr)
 {
 	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
 	struct kprobe *p = kprobe_running();
-	const struct exception_table_entry *entry;
 
 	switch(kcb->kprobe_status) {
-	case KPROBE_SWAP_INST:
-		/* We are here because the instruction replacement failed */
-		return 0;
 	case KPROBE_HIT_SS:
 	case KPROBE_REENTER:
 		/*
@@ -593,32 +417,11 @@ static int kprobe_trap_handler(struct pt_regs *regs, int trapnr)
 	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(p);
-
-		/*
-		 * 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 (p->fault_handler && p->fault_handler(p, regs, trapnr))
-			return 1;
-
-		/*
 		 * In case the user-specified fault handler returned
 		 * zero, try to fix up.
 		 */
-		entry = search_exception_tables(regs->psw.addr);
-		if (entry) {
-			regs->psw.addr = extable_fixup(entry);
+		if (fixup_exception(regs))
 			return 1;
-		}
-
 		/*
 		 * fixup_exception() could not handle it,
 		 * Let do_page_fault() fix it.
@@ -682,72 +485,19 @@ int kprobe_exceptions_notify(struct notifier_block *self,
 }
 NOKPROBE_SYMBOL(kprobe_exceptions_notify);
 
-int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
-{
-	struct jprobe *jp = container_of(p, struct jprobe, kp);
-	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-	unsigned long stack;
-
-	memcpy(&kcb->jprobe_saved_regs, regs, sizeof(struct pt_regs));
-
-	/* setup return addr to the jprobe handler routine */
-	regs->psw.addr = (unsigned long) jp->entry;
-	regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT);
-
-	/* r15 is the stack pointer */
-	stack = (unsigned long) regs->gprs[15];
-
-	memcpy(kcb->jprobes_stack, (void *) stack, MIN_STACK_SIZE(stack));
-
-	/*
-	 * jprobes use jprobe_return() which skips the normal return
-	 * path of the function, and this messes up the accounting of the
-	 * function graph tracer to get messed up.
-	 *
-	 * Pause function graph tracing while performing the jprobe function.
-	 */
-	pause_graph_tracing();
-	return 1;
-}
-NOKPROBE_SYMBOL(setjmp_pre_handler);
-
-void jprobe_return(void)
-{
-	asm volatile(".word 0x0002");
-}
-NOKPROBE_SYMBOL(jprobe_return);
-
-int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
+int __init arch_init_kprobes(void)
 {
-	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-	unsigned long stack;
-
-	/* It's OK to start function graph tracing again */
-	unpause_graph_tracing();
-
-	stack = (unsigned long) kcb->jprobe_saved_regs.gprs[15];
-
-	/* Put the regs back */
-	memcpy(regs, &kcb->jprobe_saved_regs, sizeof(struct pt_regs));
-	/* put the stack back */
-	memcpy((void *) stack, kcb->jprobes_stack, MIN_STACK_SIZE(stack));
-	preempt_enable_no_resched();
-	return 1;
+	return 0;
 }
-NOKPROBE_SYMBOL(longjmp_break_handler);
 
-static struct kprobe trampoline = {
-	.addr = (kprobe_opcode_t *) &kretprobe_trampoline,
-	.pre_handler = trampoline_probe_handler
-};
-
-int __init arch_init_kprobes(void)
+int __init arch_populate_kprobe_blacklist(void)
 {
-	return register_kprobe(&trampoline);
+	return kprobe_add_area_blacklist((unsigned long)__irqentry_text_start,
+					 (unsigned long)__irqentry_text_end);
 }
 
 int arch_trampoline_kprobe(struct kprobe *p)
 {
-	return p->addr == (kprobe_opcode_t *) &kretprobe_trampoline;
+	return 0;
 }
 NOKPROBE_SYMBOL(arch_trampoline_kprobe);