arm64: Treat all entry code as non-kprobe-able

Entry symbols are not kprobe safe. So blacklist them for kprobing.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
[catalin.marinas@arm.com: Do not include syscall wrappers in .entry.text]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/kernel/entry.S

@@ -242,6 +242,7 @@ tsk	.req	x28		// current thread_info
 /*
  * Exception vectors.
  */
+	.pushsection ".entry.text", "ax"
 
 	.align	11
 ENTRY(vectors)
@@ -774,6 +775,8 @@ __ni_sys_trace:
 	bl	do_ni_syscall
 	b	__sys_trace_return
 
+	.popsection				// .entry.text
+
 /*
  * Special system call wrappers.
  */

arch/arm64/kernel/probes/kprobes.c

@@ -30,6 +30,7 @@
 #include <asm/insn.h>
 #include <asm/uaccess.h>
 #include <asm/irq.h>
+#include <asm-generic/sections.h>
 
 #include "decode-insn.h"
 
@@ -519,6 +520,31 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
 	return 1;
 }
 
+bool arch_within_kprobe_blacklist(unsigned long addr)
+{
+	extern char __idmap_text_start[], __idmap_text_end[];
+	extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[];
+
+	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;
+	}
+
+	return false;
+}
+
 int __init arch_init_kprobes(void)
 {
 	return 0;

arch/arm64/kernel/vmlinux.lds.S

@@ -118,6 +118,7 @@ SECTIONS
 			__exception_text_end = .;
 			IRQENTRY_TEXT
 			SOFTIRQENTRY_TEXT
+			ENTRY_TEXT
 			TEXT_TEXT
 			SCHED_TEXT
 			LOCK_TEXT