linux-kernel - [RFC PATCH 10/14] x86/sev-es: Make sev_es_enable_key __ro_after

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: <20230705181256.3539027-11-vschneid@redhat.com>
Date:   Wed,  5 Jul 2023 19:12:52 +0100
From:   Valentin Schneider <vschneid@...hat.com>
To:     linux-kernel@...r.kernel.org, linux-trace-kernel@...r.kernel.org,
        linux-doc@...r.kernel.org, kvm@...r.kernel.org, linux-mm@...ck.org,
        bpf@...r.kernel.org, x86@...nel.org
Cc:     Steven Rostedt <rostedt@...dmis.org>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Jonathan Corbet <corbet@....net>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Andy Lutomirski <luto@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Frederic Weisbecker <frederic@...nel.org>,
        "Paul E. McKenney" <paulmck@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Uladzislau Rezki <urezki@...il.com>,
        Christoph Hellwig <hch@...radead.org>,
        Lorenzo Stoakes <lstoakes@...il.com>,
        Josh Poimboeuf <jpoimboe@...nel.org>,
        Kees Cook <keescook@...omium.org>,
        Sami Tolvanen <samitolvanen@...gle.com>,
        Ard Biesheuvel <ardb@...nel.org>,
        Nicholas Piggin <npiggin@...il.com>,
        Juerg Haefliger <juerg.haefliger@...onical.com>,
        Nicolas Saenz Julienne <nsaenz@...nel.org>,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        Nadav Amit <namit@...are.com>,
        Dan Carpenter <error27@...il.com>,
        Chuang Wang <nashuiliang@...il.com>,
        Yang Jihong <yangjihong1@...wei.com>,
        Petr Mladek <pmladek@...e.com>,
        "Jason A. Donenfeld" <Jason@...c4.com>, Song Liu <song@...nel.org>,
        Julian Pidancet <julian.pidancet@...cle.com>,
        Tom Lendacky <thomas.lendacky@....com>,
        Dionna Glaze <dionnaglaze@...gle.com>,
        Thomas Weißschuh <linux@...ssschuh.net>,
        Juri Lelli <juri.lelli@...hat.com>,
        Daniel Bristot de Oliveira <bristot@...hat.com>,
        Marcelo Tosatti <mtosatti@...hat.com>,
        Yair Podemsky <ypodemsk@...hat.com>
Subject: [RFC PATCH 10/14] x86/sev-es: Make sev_es_enable_key __ro_after_init

objtool now warns about it:

  vmlinux.o: warning: objtool: exc_nmi+0xbf: Non __ro_after_init static key "sev_es_enable_key" in .noinstr section
  vmlinux.o: warning: objtool: exc_nmi+0x4d: Non __ro_after_init static key "sev_es_enable_key" in .noinstr section
  vmlinux.o: warning: objtool: exc_nmi+0xc: Non __ro_after_init static key "sev_es_enable_key" in .noinstr section

The key can only be enabled (and not disabled) in the __init function
sev_es_init_vc_handling(), so mark it as __ro_after_init.

Signed-off-by: Valentin Schneider <vschneid@...hat.com>
---
 arch/x86/kernel/sev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index b031244d6d2df..4178e18383232 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -113,7 +113,7 @@ struct ghcb_state {
 };
 
 static DEFINE_PER_CPU(struct sev_es_runtime_data*, runtime_data);
-DEFINE_STATIC_KEY_FALSE(sev_es_enable_key);
+DEFINE_STATIC_KEY_FALSE_RO(sev_es_enable_key);
 
 static DEFINE_PER_CPU(struct sev_es_save_area *, sev_vmsa);
 
-- 
2.31.1