1 files changed, 35 insertions, 21 deletions

diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 86d77ff056a6..bd7b1a035459 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -45,7 +45,7 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset)
 {
 	kprobe_opcode_t *addr = NULL;
 
-#ifdef PPC64_ELF_ABI_v2
+#ifdef CONFIG_PPC64_ELF_ABI_V2
 	/* PPC64 ABIv2 needs local entry point */
 	addr = (kprobe_opcode_t *)kallsyms_lookup_name(name);
 	if (addr && !offset) {
@@ -63,7 +63,7 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset)
 #endif
 			addr = (kprobe_opcode_t *)ppc_function_entry(addr);
 	}
-#elif defined(PPC64_ELF_ABI_v1)
+#elif defined(CONFIG_PPC64_ELF_ABI_V1)
 	/*
 	 * 64bit powerpc ABIv1 uses function descriptors:
 	 * - Check for the dot variant of the symbol first.
@@ -105,6 +105,27 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset)
 	return addr;
 }
 
+static bool arch_kprobe_on_func_entry(unsigned long offset)
+{
+#ifdef CONFIG_PPC64_ELF_ABI_V2
+#ifdef CONFIG_KPROBES_ON_FTRACE
+	return offset <= 16;
+#else
+	return offset <= 8;
+#endif
+#else
+	return !offset;
+#endif
+}
+
+/* XXX try and fold the magic of kprobe_lookup_name() in this */
+kprobe_opcode_t *arch_adjust_kprobe_addr(unsigned long addr, unsigned long offset,
+					 bool *on_func_entry)
+{
+	*on_func_entry = arch_kprobe_on_func_entry(offset);
+	return (kprobe_opcode_t *)(addr + offset);
+}
+
 void *alloc_insn_page(void)
 {
 	void *page;
@@ -124,13 +145,13 @@ int arch_prepare_kprobe(struct kprobe *p)
 {
 	int ret = 0;
 	struct kprobe *prev;
-	struct ppc_inst insn = ppc_inst_read(p->addr);
+	ppc_inst_t insn = ppc_inst_read(p->addr);
 
 	if ((unsigned long)p->addr & 0x03) {
 		printk("Attempt to register kprobe at an unaligned address\n");
 		ret = -EINVAL;
-	} else if (IS_MTMSRD(insn) || IS_RFID(insn)) {
-		printk("Cannot register a kprobe on mtmsr[d]/rfi[d]\n");
+	} else if (!can_single_step(ppc_inst_val(insn))) {
+		printk("Cannot register a kprobe on instructions that can't be single stepped\n");
 		ret = -EINVAL;
 	} else if ((unsigned long)p->addr & ~PAGE_MASK &&
 		   ppc_inst_prefixed(ppc_inst_read(p->addr - 1))) {
@@ -140,7 +161,13 @@ int arch_prepare_kprobe(struct kprobe *p)
 	preempt_disable();
 	prev = get_kprobe(p->addr - 1);
 	preempt_enable_no_resched();
-	if (prev && ppc_inst_prefixed(ppc_inst_read(prev->ainsn.insn))) {
+
+	/*
+	 * When prev is a ftrace-based kprobe, we don't have an insn, and it
+	 * doesn't probe for prefixed instruction.
+	 */
+	if (prev && !kprobe_ftrace(prev) &&
+	    ppc_inst_prefixed(ppc_inst_read(prev->ainsn.insn))) {
 		printk("Cannot register a kprobe on the second word of prefixed instruction\n");
 		ret = -EINVAL;
 	}
@@ -218,19 +245,6 @@ static nokprobe_inline void set_current_kprobe(struct kprobe *p, struct pt_regs
 	kcb->kprobe_saved_msr = regs->msr;
 }
 
-bool arch_kprobe_on_func_entry(unsigned long offset)
-{
-#ifdef PPC64_ELF_ABI_v2
-#ifdef CONFIG_KPROBES_ON_FTRACE
-	return offset <= 16;
-#else
-	return offset <= 8;
-#endif
-#else
-	return !offset;
-#endif
-}
-
 void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs)
 {
 	ri->ret_addr = (kprobe_opcode_t *)regs->link;
@@ -244,7 +258,7 @@ NOKPROBE_SYMBOL(arch_prepare_kretprobe);
 static int try_to_emulate(struct kprobe *p, struct pt_regs *regs)
 {
 	int ret;
-	struct ppc_inst insn = ppc_inst_read(p->ainsn.insn);
+	ppc_inst_t insn = ppc_inst_read(p->ainsn.insn);
 
 	/* regs->nip is also adjusted if emulate_step returns 1 */
 	ret = emulate_step(regs, insn);
@@ -261,7 +275,7 @@ static int try_to_emulate(struct kprobe *p, struct pt_regs *regs)
 		 * So, we should never get here... but, its still
 		 * good to catch them, just in case...
 		 */
-		printk("Can't step on instruction %s\n", ppc_inst_as_str(insn));
+		printk("Can't step on instruction %08lx\n", ppc_inst_as_ulong(insn));
 		BUG();
 	} else {
 		/*