From: Andrew Cooper <Andrew.Cooper3@citrix.com>
To: Josh Poimboeuf <jpoimboe@redhat.com>, "x86@kernel.org" <x86@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Miroslav Benes <mbenes@suse.cz>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Juergen Gross <jgross@suse.com>,
Stefano Stabellini <sstabellini@kernel.org>,
"xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
Subject: Re: [PATCH v2 06/25] x86/xen: Add ANNOTATE_ENDBR to startup_xen()
Date: Tue, 19 Apr 2022 11:42:12 +0000 [thread overview]
Message-ID: <b94cbac6-0a4d-8e4a-ec58-bbd46e385d45@citrix.com> (raw)
In-Reply-To: <a87bd48b06d11ec4b98122a429e71e489b4e48c3.1650300597.git.jpoimboe@redhat.com>
On 18/04/2022 17:50, Josh Poimboeuf wrote:
> The startup_xen() kernel entry point is referenced by the ".note.Xen"
> section, but is presumably not indirect-branched to.
It's the real entrypoint of the VM. It's "got to" by setting %rip
during vcpu setup.
We could in principle support starting a PV VM with CET active, but that
sounds like an enormous quantity of effort for very little gain. CET
for Xen PV requires paravirt anyway (because the kernel runs in CPL!=0)
so decisions like this can wait until someone feels like doing the work.
> Add ANNOTATE_ENDBR
> to silence future objtool warnings.
>
> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> Cc: Juergen Gross <jgross@suse.com>
> Cc: Stefano Stabellini <sstabellini@kernel.org>
> Cc: xen-devel@lists.xenproject.org
> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
FWIW, Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>, preferably
with the commit message tweaked to remove the uncertainty.
~Andrew
next prev parent reply other threads:[~2022-04-19 11:43 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-18 16:50 [PATCH v2 00/25] objtool: Interface overhaul Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 01/25] objtool: Enable unreachable warnings for CLANG LTO Josh Poimboeuf
2022-04-19 20:08 ` [tip: x86/urgent] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 02/25] libsubcmd: Fix OPTION_GROUP sorting Josh Poimboeuf
2022-04-22 10:35 ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 03/25] x86/static_call: Add ANNOTATE_NOENDBR to static call trampoline Josh Poimboeuf
2022-04-19 20:08 ` [tip: x86/urgent] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 04/25] x86/retpoline: Add ANNOTATE_ENDBR for retpolines Josh Poimboeuf
2022-04-19 20:08 ` [tip: x86/urgent] x86/retpoline: Add ANNOTATE_NOENDBR " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 05/25] x86/uaccess: Add ENDBR to __put_user_nocheck*() Josh Poimboeuf
2022-04-19 20:08 ` [tip: x86/urgent] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 06/25] x86/xen: Add ANNOTATE_ENDBR to startup_xen() Josh Poimboeuf
2022-04-19 11:42 ` Andrew Cooper [this message]
2022-04-19 11:57 ` Peter Zijlstra
2022-04-19 12:06 ` Juergen Gross
2022-04-19 12:12 ` Andrew Cooper
2022-04-19 13:10 ` Peter Zijlstra
2022-04-19 14:25 ` Andrew Cooper
2022-04-19 20:08 ` [tip: x86/urgent] x86/xen: Add ANNOTATE_NOENDBR " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 07/25] objtool: Reorganize cmdline options Josh Poimboeuf
2022-04-22 10:35 ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 08/25] objtool: Ditch subcommands Josh Poimboeuf
2022-04-22 10:35 ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 09/25] objtool: Don't print parentheses in function addresses Josh Poimboeuf
2022-04-22 10:35 ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 10/25] objtool: Print data address for "!ENDBR" data warnings Josh Poimboeuf
2022-04-19 20:08 ` [tip: x86/urgent] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 11/25] objtool: Use offstr() to print address of missing ENDBR Josh Poimboeuf
2022-04-19 20:08 ` [tip: x86/urgent] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 12/25] objtool: Add option to print section addresses Josh Poimboeuf
2022-04-22 10:35 ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 13/25] scripts: Create objdump-func helper script Josh Poimboeuf
2022-04-19 11:15 ` Peter Zijlstra
2022-04-19 16:09 ` Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 14/25] objtool: Make stack validation optional Josh Poimboeuf
2022-04-22 10:35 ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 15/25] objtool: Rework ibt and extricate from stack validation Josh Poimboeuf
2022-04-20 17:25 ` Miroslav Benes
2022-04-22 10:50 ` Peter Zijlstra
2022-04-22 15:17 ` Josh Poimboeuf
2022-04-25 6:27 ` Miroslav Benes
2022-04-22 10:35 ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 16/25] objtool: Extricate sls " Josh Poimboeuf
2022-04-22 10:35 ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 17/25] objtool: Add CONFIG_OBJTOOL Josh Poimboeuf
2022-04-19 11:22 ` Peter Zijlstra
2022-04-22 10:35 ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 18/25] objtool: Make stack validation frame-pointer-specific Josh Poimboeuf
2022-04-22 10:35 ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 19/25] objtool: Make static call annotation optional Josh Poimboeuf
2022-04-22 10:35 ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 20/25] objtool: Make jump label hack optional Josh Poimboeuf
2022-04-22 10:34 ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 21/25] objtool: Make noinstr hacks optional Josh Poimboeuf
2022-04-22 10:34 ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 22/25] objtool: Rename "VMLINUX_VALIDATION" -> "NOINSTR_VALIDATION" Josh Poimboeuf
2022-04-22 10:34 ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 23/25] objtool: Add HAVE_NOINSTR_VALIDATION Josh Poimboeuf
2022-04-22 10:34 ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 24/25] objtool: Remove --lto and --vmlinux in favor of --link Josh Poimboeuf
2022-04-20 17:25 ` Miroslav Benes
2022-04-22 10:34 ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2022-04-18 16:50 ` [PATCH v2 25/25] objtool: Update documentation Josh Poimboeuf
2022-04-22 10:34 ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2022-04-19 11:51 ` [PATCH v2 00/25] objtool: Interface overhaul Peter Zijlstra
2022-04-19 15:36 ` Josh Poimboeuf
2022-04-19 16:43 ` Peter Zijlstra
2022-04-20 17:27 ` Miroslav Benes
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