public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Thomas Gleixner <tglx@linutronix.de>
To: Miaohe Lin <linmiaohe@huawei.com>,
	mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com
Cc: hpa@zytor.com, x86@kernel.org, linux-kernel@vger.kernel.org,
	linmiaohe@huawei.com
Subject: Re: [PATCH v2] x86/alternative: fix undefined reference to __ibt_endbr_seal[_end]
Date: Fri, 02 Dec 2022 12:59:36 +0100	[thread overview]
Message-ID: <87y1rqow2f.ffs@tglx> (raw)
In-Reply-To: <20221011113803.956808-1-linmiaohe@huawei.com>

On Tue, Oct 11 2022 at 19:38, Miaohe Lin wrote:
> Due to the explicit 'noinline' GCC-7.3 is not able to optimize away the
> argument setup of:
>
> 	apply_ibt_endbr(__ibt_endbr_seal, __ibt_enbr_seal_end);
>
> even when X86_KERNEL_IBT=n and the function is an empty stub which leads
> to link errors due to missing __ibt_endbr_seal* symbols like below:
>
> ld: arch/x86/kernel/alternative.o: in function
> `alternative_instructions':
> alternative.c:(.init.text+0x15d): undefined reference to
> `__ibt_endbr_seal_end'
> ld: alternative.c:(.init.text+0x164): undefined reference to
> `__ibt_endbr_seal'

This is incomplete because the noinline is only visible within
alternative.c, but there is another caller in module.c

This needs an inline stub in the header to be correct.

Thanks,

        tglx

  parent reply	other threads:[~2022-12-02 11:59 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-11 11:38 [PATCH v2] x86/alternative: fix undefined reference to __ibt_endbr_seal[_end] Miaohe Lin
2022-10-11  3:46 ` Miaohe Lin
2022-12-02  8:46 ` Miaohe Lin
2022-12-02 11:59 ` Thomas Gleixner [this message]
2022-12-03  1:20   ` Miaohe Lin
2022-12-05 10:59 ` [tip: x86/urgent] x86/alternative: Remove noinline from __ibt_endbr_seal[_end]() stubs tip-bot2 for Miaohe Lin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87y1rqow2f.ffs@tglx \
    --to=tglx@linutronix.de \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=hpa@zytor.com \
    --cc=linmiaohe@huawei.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox