From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Masami Hiramatsu , Russell King Subject: [PATCH 4.16 048/110] ARM: 8771/1: kprobes: Prohibit kprobes on do_undefinstr Date: Mon, 21 May 2018 23:11:45 +0200 Message-Id: <20180521210508.942917094@linuxfoundation.org> In-Reply-To: <20180521210503.823249477@linuxfoundation.org> References: <20180521210503.823249477@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Masami Hiramatsu 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 Cc: stable@vger.kernel.org Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman --- 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 #include #include +#include #include #include #include @@ -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.