From mboxrd@z Thu Jan 1 00:00:00 1970 From: mhiramat@kernel.org (Masami Hiramatsu) Date: Sat, 24 Feb 2018 17:02:50 +0900 Subject: [PATCH 1/2] arm: kprobes: Prohibit kprobes on do_undefinstr Message-ID: <151945937038.11045.14421944772744094357.stgit@devbox> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 --- arch/arm/kernel/traps.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 5e3633c24e63..2fe87109ae46 100644 --- 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_hook *hook) 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 @@ asmlinkage void do_undefinstr(struct pt_regs *regs) arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6); } +NOKPROBE_SYMBOL(do_undefinstr) /* * Handle FIQ similarly to NMI on x86 systems.