linux-kernel - Re: [PATCH -tip v8 03/13] kprobes: treewide: Remove trampoline_address from kretprobe_trampoline

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <YOKut2jZ4f+oSKAI@gmail.com>
Date:   Mon, 5 Jul 2021 09:03:19 +0200
From:   Ingo Molnar <mingo@...nel.org>
To:     Masami Hiramatsu <mhiramat@...nel.org>
Cc:     Steven Rostedt <rostedt@...dmis.org>,
        Josh Poimboeuf <jpoimboe@...hat.com>, X86 ML <x86@...nel.org>,
        Daniel Xu <dxu@...uu.xyz>, linux-kernel@...r.kernel.org,
        bpf@...r.kernel.org, kuba@...nel.org, mingo@...hat.com,
        ast@...nel.org, Thomas Gleixner <tglx@...utronix.de>,
        Borislav Petkov <bp@...en8.de>,
        Peter Zijlstra <peterz@...radead.org>, kernel-team@...com,
        yhs@...com, linux-ia64@...r.kernel.org,
        Abhishek Sagar <sagar.abhishek@...il.com>,
        Andrii Nakryiko <andrii.nakryiko@...il.com>
Subject: Re: [PATCH -tip v8 03/13] kprobes: treewide: Remove
 trampoline_address from kretprobe_trampoline_handler()


* Masami Hiramatsu <mhiramat@...nel.org> wrote:

> --- a/include/linux/kprobes.h
> +++ b/include/linux/kprobes.h
> @@ -197,15 +197,23 @@ extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
>  				   struct pt_regs *regs);
>  extern int arch_trampoline_kprobe(struct kprobe *p);
>  
> +void kretprobe_trampoline(void);
> +/*
> + * Since some architecture uses structured function pointer,
> + * use dereference_function_descriptor() to get real function address.
> + */
> +static nokprobe_inline void *kretprobe_trampoline_addr(void)
> +{
> +	return dereference_kernel_function_descriptor(kretprobe_trampoline);
> +}

Could we please also make 'kretprobe_trampoline' harder to use 
accidentally, such by naming it appropriately?

__kretprobe_trampoline would be a good first step I guess.

Thanks,

	Ingo