samples/kprobes: Add ARM support

Plenty of architectures are already supported and this adds ARM
support.
Signed-off-by: Marc Koderer <marc@koderer.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20210112154054.17138-1-marc@koderer.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

samples/kprobes/kprobe_example.c

@@ -43,6 +43,10 @@ static int __kprobes handler_pre(struct kprobe *p, struct pt_regs *regs)
 			" pstate = 0x%lx\n",
 		p->symbol_name, p->addr, (long)regs->pc, (long)regs->pstate);
 #endif
+#ifdef CONFIG_ARM
+	pr_info("<%s> pre_handler: p->addr = 0x%p, pc = 0x%lx, cpsr = 0x%lx\n",
+		p->symbol_name, p->addr, (long)regs->ARM_pc, (long)regs->ARM_cpsr);
+#endif
 #ifdef CONFIG_S390
 	pr_info("<%s> pre_handler: p->addr, 0x%p, ip = 0x%lx, flags = 0x%lx\n",
 		p->symbol_name, p->addr, regs->psw.addr, regs->flags);
@@ -72,6 +76,10 @@ static void __kprobes handler_post(struct kprobe *p, struct pt_regs *regs,
 	pr_info("<%s> post_handler: p->addr = 0x%p, pstate = 0x%lx\n",
 		p->symbol_name, p->addr, (long)regs->pstate);
 #endif
+#ifdef CONFIG_ARM
+	pr_info("<%s> post_handler: p->addr = 0x%p, cpsr = 0x%lx\n",
+		p->symbol_name, p->addr, (long)regs->ARM_cpsr);
+#endif
 #ifdef CONFIG_S390
 	pr_info("<%s> pre_handler: p->addr, 0x%p, flags = 0x%lx\n",
 		p->symbol_name, p->addr, regs->flags);