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Commit eb0146da authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Russell King
Browse files

ARM: 8771/1: kprobes: Prohibit kprobes on do_undefinstr 



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: 24ba613c ("ARM kprobes: core code")
Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
parent 70948c05

arch/arm/kernel/traps.c

+4 −1
Original line number Diff line number Diff line
@@ -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_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.