linux-kernel - Re: [PATCH v1] LoongArch: Handle special PC in unwind_next

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] [day] [month] [year] [list]

Message-ID: <e4101f85-d580-0739-4282-13c80abceed3@loongson.cn>
Date: Tue, 9 Dec 2025 10:08:23 +0800
From: Tiezhu Yang <yangtiezhu@...ngson.cn>
To: Jinyang He <hejinyang@...ngson.cn>
Cc: Huacai Chen <chenhuacai@...nel.org>, Xi Zhang <zhangxi@...inos.cn>,
 Xianglai Li <lixianglai@...ngson.cn>, loongarch@...ts.linux.dev,
 linux-kernel@...r.kernel.org, Bibo Mao <maobibo@...ngson.cn>
Subject: Re: [PATCH v1] LoongArch: Handle special PC in unwind_next_frame()

On 2025/11/26 下午5:09, Tiezhu Yang wrote:
...
>> I will do more test and send v2 later.
> 
> Here are the draft changes:
...
> +#if IS_ENABLED(CONFIG_KVM)
> +       unsigned long old, new, size;
> +
> +       if (get_kvm_entry_info) {
> +               get_kvm_entry_info(&old, &new, &size);
> +               if (ra >= new && ra < new + size)
> +                       return old + (ra - new);
> +       }
> +#endif
...
> 
> I tested with config UNWINDER_ORC, it can unwind from kvm_handle_exit()
> to its previous frame kvm_exc_entry() which is the end of stack, there
> is no "unreliable stack" in debug mode and also no timeout for kernel
> livepatching.
> 
> I also tested with config UNWINDER_PROLOGUE and config UNWINDER_GUESS,
> no build errors and the virtual machine can boot normally.
> 
> I would like to receive comments for the draft changes first and then
> send the formal v2, the function and variable name may be not proper,
> so any comments are welcome.
> 
> Since the merge window is coming soon and I am busy with the other
> higher priority stuff, so maybe I will send v2 after the merge window.

FYI, after some internal discussions, it will only modify the code of
KVM to fix this problem, so please ignore this patch and the above diff,
I will not send new version and please wait for the KVM patch.

Thanks,
Tiezhu