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From: Masami Hiramatsu <mhiramat@kernel.org>
To: Russell King <linux@armlinux.org.uk>
Cc: Wang Nan <wangnan0@huawei.com>, Will Deacon <will.deacon@arm.com>,
	Jon Medhurst <tixy@linaro.org>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, mhiramat@kernel.org,
	David Long <dave.long@linaro.org>,
	stable@vger.kernel.org
Subject: [BUGFIX PATCH v3 3/4] arm: kprobes: Prohibit kprobes on do_undefinstr
Date: Fri,  4 May 2018 13:15:58 +0900	[thread overview]
Message-ID: <152540735813.29650.10807161581632067171.stgit@devbox> (raw)
In-Reply-To: <152540727123.29650.13679359124038587629.stgit@devbox>

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
---
 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 <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.

  parent reply	other threads:[~2018-05-04  4:16 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-04  4:14 [BUGFIX PATCH v3 0/4] arm: kprobes: Fix to prohibit probing on unsafe functions Masami Hiramatsu
2018-05-04  4:15 ` [BUGFIX PATCH v3 1/4] arm: kprobes: Fix to use get_kprobe_ctlblk after irq-disabed Masami Hiramatsu
2018-05-04  4:15 ` [BUGFIX PATCH v3 2/4] arm: kprobes: Prohibit probing on optimized_callback Masami Hiramatsu
2018-05-04  4:15 ` Masami Hiramatsu [this message]
2018-05-04  4:16 ` [BUGFIX PATCH v3 4/4] arm: kprobes: Prohibit kprobes on get_user functions Masami Hiramatsu
2018-05-08 11:25 ` [BUGFIX PATCH v3 0/4] arm: kprobes: Fix to prohibit probing on unsafe functions Russell King - ARM Linux
2018-05-12  0:42   ` Masami Hiramatsu
2018-05-12  4:31     ` Greg KH
2018-05-12  9:06     ` Russell King - ARM Linux
2018-05-12 11:31   ` Masami Hiramatsu
2018-05-12 17:29     ` Florian Fainelli
2018-05-13  1:55       ` Masami Hiramatsu

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