lkml.org 
[lkml]   [2018]   [May]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.14 35/95] ARM: 8771/1: kprobes: Prohibit kprobes on do_undefinstr
Date
4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Masami Hiramatsu <mhiramat@kernel.org>

commit eb0146daefdde65665b7f076fbff7b49dade95b9 upstream.

Prohibit kprobes on do_undefinstr because kprobes on
arm is implemented by undefined instruction. This means
if we probe do_undefinstr(), it can cause infinit
recursive exception.

Fixes: 24ba613c9d6c ("ARM kprobes: core code")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/arm/kernel/traps.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -19,6 +19,7 @@
#include <linux/uaccess.h>
#include <linux/hardirq.h>
#include <linux/kdebug.h>
+#include <linux/kprobes.h>
#include <linux/module.h>
#include <linux/kexec.h>
#include <linux/bug.h>
@@ -417,7 +418,8 @@ void unregister_undef_hook(struct undef_
raw_spin_unlock_irqrestore(&undef_lock, flags);
}

-static int call_undef_hook(struct pt_regs *regs, unsigned int instr)
+static nokprobe_inline
+int call_undef_hook(struct pt_regs *regs, unsigned int instr)
{
struct undef_hook *hook;
unsigned long flags;
@@ -490,6 +492,7 @@ die_sig:

arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6);
}
+NOKPROBE_SYMBOL(do_undefinstr)

/*
* Handle FIQ similarly to NMI on x86 systems.

\
 
 \ /
  Last update: 2018-05-22 00:05    [W:0.358 / U:1.584 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site