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

commit 888b3c8720e0a4033db09ba2364afde6a4763638 upstream.

Entry symbols are not kprobe safe. So blacklist them for kprobing.

[dave.long@linaro.org: Remove check for hypervisor text]

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

@@ -207,6 +207,7 @@ tsk	.req	x28		// current thread_info
 /*
  * Exception vectors.
  */
+	.pushsection ".entry.text", "ax"
 
 	.align	11
 ENTRY(vectors)
@@ -738,6 +739,8 @@ __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"
 
@@ -516,6 +517,23 @@ 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[];
+
+	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;
+
+
+	return false;
+}
+
 int __init arch_init_kprobes(void)
 {
 	return 0;

arch/arm64/kernel/vmlinux.lds.S

@@ -102,6 +102,7 @@ SECTIONS
 			*(.exception.text)
 			__exception_text_end = .;
 			IRQENTRY_TEXT
+			ENTRY_TEXT
 			TEXT_TEXT
 			SCHED_TEXT
 			LOCK_TEXT