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From: James Morse <james.morse@arm.com>
To: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	Pratyush Anand <panand@redhat.com>,
	"David A . Long" <dave.long@linaro.org>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/3] arm64: kprobes: Remove unneeded RODATA check
Date: Thu, 3 Jan 2019 17:07:22 +0000	[thread overview]
Message-ID: <3bebf737-fe6b-33c8-e535-5d155591b303@arm.com> (raw)
In-Reply-To: <154502887509.30629.17754148993239954461.stgit@devbox>

Hi!

On 17/12/2018 06:41, Masami Hiramatsu wrote:
> Remove unneeded RODATA check from arch_prepare_kprobe().
> 
> Since check_kprobe_address_safe() already ensured that
> the probe address is in kernel text, we don't need to
> check whether the address in RODATA or not. That must
> be always false.

So it does!

Reviewed-by: James Morse <james.morse@arm.com>


Thanks

James

> diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c
> index b2d4b7428ebc..1dae500d0a81 100644
> --- a/arch/arm64/kernel/probes/kprobes.c
> +++ b/arch/arm64/kernel/probes/kprobes.c
> @@ -91,8 +91,6 @@ static void __kprobes arch_simulate_insn(struct kprobe *p, struct pt_regs *regs)
>  int __kprobes arch_prepare_kprobe(struct kprobe *p)
>  {
>  	unsigned long probe_addr = (unsigned long)p->addr;
> -	extern char __start_rodata[];
> -	extern char __end_rodata[];
>  
>  	if (probe_addr & 0x3)
>  		return -EINVAL;
> @@ -106,10 +104,6 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
>  	if (search_exception_tables(probe_addr))
>  		return -EINVAL;
>  
> -	if (probe_addr >= (unsigned long) __start_rodata &&
> -	    probe_addr <= (unsigned long) __end_rodata)
> -		return -EINVAL;
> -
>  	/* decode instruction */
>  	switch (arm_kprobe_decode_insn(p->addr, &p->ainsn)) {
>  	case INSN_REJECTED:	/* insn not supported */
> 


  reply	other threads:[~2019-01-03 17:07 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-17  6:40 [PATCH 0/3] arm64: kprobes: Fix blacklist checking on arm64 Masami Hiramatsu
2018-12-17  6:40 ` [PATCH 1/3] arm64: kprobes: Move extable address check into arch_prepare_kprobe() Masami Hiramatsu
2019-01-03 17:05   ` James Morse
2019-01-08  2:39     ` Masami Hiramatsu
2019-01-08 17:13       ` James Morse
2019-01-09  2:05         ` Masami Hiramatsu
2019-01-11 18:22           ` James Morse
2019-01-15  5:49             ` Masami Hiramatsu
2018-12-17  6:41 ` [PATCH 2/3] arm64: kprobes: Remove unneeded RODATA check Masami Hiramatsu
2019-01-03 17:07   ` James Morse [this message]
2018-12-17  6:41 ` [PATCH 3/3] arm64: kprobes: Move exception_text check in blacklist Masami Hiramatsu

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