From: Peter Zijlstra <peterz@infradead.org>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>,
Borislav Petkov <bp@alien8.de>, Andy Lutomirski <luto@kernel.org>,
Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@linux.intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Elena Reshetova <elena.reshetova@intel.com>,
x86@kernel.org, linux-coco@lists.linux.dev,
linux-kernel@vger.kernel.org, kernel test robot <lkp@intel.com>
Subject: Re: [PATCH] x86/tdx: Do not corrupt frame-pointer in __tdx_hypercall()
Date: Tue, 31 Jan 2023 09:34:12 +0100 [thread overview]
Message-ID: <Y9jShNfS/d8LGu8w@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20230130135354.27674-1-kirill.shutemov@linux.intel.com>
On Mon, Jan 30, 2023 at 04:53:54PM +0300, Kirill A. Shutemov wrote:
> If compiled with CONFIG_FRAME_POINTER=y, objtool in not happy that
> __tdx_hypercall() messes up RBP.
>
> objtool: __tdx_hypercall+0x7f: return with modified stack frame
>
> Rework the function to store TDX_HCALL_ flags on stack instead of RBP.
Also, on IRC you mentioned that per TDX spec, BP is a valid argument
register too and you were going to raise this and get it fixed, TDX
hypercalls must not use BP to pass data.
next prev parent reply other threads:[~2023-01-31 8:34 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-30 13:53 [PATCH] x86/tdx: Do not corrupt frame-pointer in __tdx_hypercall() Kirill A. Shutemov
2023-01-31 8:32 ` Peter Zijlstra
2023-01-31 8:50 ` Kirill A. Shutemov
2023-01-31 8:34 ` Peter Zijlstra [this message]
2023-01-31 8:39 ` Kirill A. Shutemov
2023-01-31 9:39 ` Peter Zijlstra
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=Y9jShNfS/d8LGu8w@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=bp@alien8.de \
--cc=dave.hansen@intel.com \
--cc=elena.reshetova@intel.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-coco@lists.linux.dev \
--cc=linux-kernel@vger.kernel.org \
--cc=lkp@intel.com \
--cc=luto@kernel.org \
--cc=sathyanarayanan.kuppuswamy@linux.intel.com \
--cc=tglx@linutronix.de \
--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