1 files changed, 16 insertions, 130 deletions

diff --git a/arch/sparc/kernel/kprobes.c b/arch/sparc/kernel/kprobes.c
index 2d13a4fc0384..191bbaca9921 100644
--- a/arch/sparc/kernel/kprobes.c
+++ b/arch/sparc/kernel/kprobes.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* arch/sparc64/kernel/kprobes.c
  *
  * Copyright (C) 2004 David S. Miller <davem@davemloft.net>
@@ -146,18 +147,12 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
 			kcb->kprobe_status = KPROBE_REENTER;
 			prepare_singlestep(p, regs, kcb);
 			return 1;
-		} else {
-			if (*(u32 *)addr != BREAKPOINT_INSTRUCTION) {
+		} else if (*(u32 *)addr != BREAKPOINT_INSTRUCTION) {
 			/* The breakpoint instruction was removed by
 			 * another cpu right after we hit, no further
 			 * handling of this interrupt is appropriate
 			 */
-				ret = 1;
-				goto no_kprobe;
-			}
-			p = __this_cpu_read(current_kprobe);
-			if (p->break_handler && p->break_handler(p, regs))
-				goto ss_probe;
+			ret = 1;
 		}
 		goto no_kprobe;
 	}
@@ -180,10 +175,12 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
 
 	set_current_kprobe(p, regs, kcb);
 	kcb->kprobe_status = KPROBE_HIT_ACTIVE;
-	if (p->pre_handler && p->pre_handler(p, regs))
+	if (p->pre_handler && p->pre_handler(p, regs)) {
+		reset_current_kprobe();
+		preempt_enable_no_resched();
 		return 1;
+	}
 
-ss_probe:
 	prepare_singlestep(p, regs, kcb);
 	kcb->kprobe_status = KPROBE_HIT_SS;
 	return 1;
@@ -233,7 +230,7 @@ static unsigned long __kprobes relbranch_fixup(u32 insn, struct kprobe *p,
 	return regs->tnpc;
 }
 
-/* If INSN is an instruction which writes it's PC location
+/* If INSN is an instruction which writes its PC location
  * into a destination register, fix that up.
  */
 static void __kprobes retpc_fixup(struct pt_regs *regs, u32 insn,
@@ -349,23 +346,6 @@ int __kprobes kprobe_fault_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(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, trapnr))
-			return 1;
-
-		/*
 		 * In case the user-specified fault handler returned
 		 * zero, try to fix up.
 		 */
@@ -440,53 +420,6 @@ out:
 	exception_exit(prev_state);
 }
 
-/* Jprobes support.  */
-int __kprobes 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();
-
-	memcpy(&(kcb->jprobe_saved_regs), regs, sizeof(*regs));
-
-	regs->tpc  = (unsigned long) jp->entry;
-	regs->tnpc = ((unsigned long) jp->entry) + 0x4UL;
-	regs->tstate |= TSTATE_PIL;
-
-	return 1;
-}
-
-void __kprobes jprobe_return(void)
-{
-	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-	register unsigned long orig_fp asm("g1");
-
-	orig_fp = kcb->jprobe_saved_regs.u_regs[UREG_FP];
-	__asm__ __volatile__("\n"
-"1:	cmp		%%sp, %0\n\t"
-	"blu,a,pt	%%xcc, 1b\n\t"
-	" restore\n\t"
-	".globl		jprobe_return_trap_instruction\n"
-"jprobe_return_trap_instruction:\n\t"
-	"ta		0x70"
-	: /* no outputs */
-	: "r" (orig_fp));
-}
-
-extern void jprobe_return_trap_instruction(void);
-
-int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
-	u32 *addr = (u32 *) regs->tpc;
-	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
-	if (addr == (u32 *) jprobe_return_trap_instruction) {
-		memcpy(regs, &(kcb->jprobe_saved_regs), sizeof(*regs));
-		preempt_enable_no_resched();
-		return 1;
-	}
-	return 0;
-}
-
 /* The value stored in the return address register is actually 2
  * instructions before where the callee will return to.
  * Sequences usually look something like this
@@ -503,10 +436,11 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
 				      struct pt_regs *regs)
 {
 	ri->ret_addr = (kprobe_opcode_t *)(regs->u_regs[UREG_RETPC] + 8);
+	ri->fp = NULL;
 
 	/* Replace the return addr with trampoline addr */
 	regs->u_regs[UREG_RETPC] =
-		((unsigned long)kretprobe_trampoline) - 8;
+		((unsigned long)__kretprobe_trampoline) - 8;
 }
 
 /*
@@ -515,60 +449,12 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
 static int __kprobes trampoline_probe_handler(struct kprobe *p,
 					      struct pt_regs *regs)
 {
-	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;
-
-	INIT_HLIST_HEAD(&empty_rp);
-	kretprobe_hash_lock(current, &head, &flags);
+	unsigned long orig_ret_address = 0;
 
-	/*
-	 * 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
-	 */
-	hlist_for_each_entry_safe(ri, tmp, head, hlist) {
-		if (ri->task != current)
-			/* another task is sharing our hash bucket */
-			continue;
-
-		if (ri->rp && ri->rp->handler)
-			ri->rp->handler(ri, regs);
-
-		orig_ret_address = (unsigned long)ri->ret_addr;
-		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_assert(ri, orig_ret_address, trampoline_address);
+	orig_ret_address = __kretprobe_trampoline_handler(regs, NULL);
 	regs->tpc = orig_ret_address;
 	regs->tnpc = orig_ret_address + 4;
 
-	reset_current_kprobe();
-	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
@@ -579,13 +465,13 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
 
 static void __used kretprobe_trampoline_holder(void)
 {
-	asm volatile(".global kretprobe_trampoline\n"
-		     "kretprobe_trampoline:\n"
+	asm volatile(".global __kretprobe_trampoline\n"
+		     "__kretprobe_trampoline:\n"
 		     "\tnop\n"
 		     "\tnop\n");
 }
 static struct kprobe trampoline_p = {
-	.addr = (kprobe_opcode_t *) &kretprobe_trampoline,
+	.addr = (kprobe_opcode_t *) &__kretprobe_trampoline,
 	.pre_handler = trampoline_probe_handler
 };
 
@@ -596,7 +482,7 @@ int __init arch_init_kprobes(void)
 
 int __kprobes arch_trampoline_kprobe(struct kprobe *p)
 {
-	if (p->addr == (kprobe_opcode_t *)&kretprobe_trampoline)
+	if (p->addr == (kprobe_opcode_t *)&__kretprobe_trampoline)
 		return 1;
 
 	return 0;