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Message-ID: <0eb95f39-583d-498d-a7a6-829519e251e2@default>
Date:   Thu, 1 Nov 2018 02:31:46 -0700 (PDT)
From:   Zhenzhong Duan <zhenzhong.duan@oracle.com>
To:     <linux-kernel@vger.kernel.org>
Cc:     <mingo@redhat.com>, <konrad.wilk@oracle.com>, <tglx@linutronix.de>,
        <dwmw@amazon.co.uk>, <bp@suse.de>, <srinivas.eeda@oracle.com>,
        <peterz@infradead.org>, <hpa@zytor.com>
Subject: [PATCH v2 2/2] retpolines: Remove minimal stuff in retpoline support
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Sender: linux-kernel-owner@vger.kernel.org
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Now that CONFIG_RETPOLINE hard depends on compiler support, there is no
reason for minimal stuff to still exist.

This change is based on suggestion in https://lkml.org/lkml/2018/9/18/1016

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 arch/x86/include/asm/nospec-branch.h |  2 --
 arch/x86/kernel/cpu/bugs.c           | 13 ++-----------
 2 files changed, 2 insertions(+), 13 deletions(-)

diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/no=
spec-branch.h
index 8b09cbb..c202a64 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -221,8 +221,6 @@
 /* The Spectre V2 mitigation variants */
 enum spectre_v2_mitigation {
 =09SPECTRE_V2_NONE,
-=09SPECTRE_V2_RETPOLINE_MINIMAL,
-=09SPECTRE_V2_RETPOLINE_MINIMAL_AMD,
 =09SPECTRE_V2_RETPOLINE_GENERIC,
 =09SPECTRE_V2_RETPOLINE_AMD,
 =09SPECTRE_V2_IBRS_ENHANCED,
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index d0108fb..7f6d815 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -135,8 +135,6 @@ enum spectre_v2_mitigation_cmd {
=20
 static const char *spectre_v2_strings[] =3D {
 =09[SPECTRE_V2_NONE]=09=09=09=3D "Vulnerable",
-=09[SPECTRE_V2_RETPOLINE_MINIMAL]=09=09=3D "Vulnerable: Minimal generic AS=
M retpoline",
-=09[SPECTRE_V2_RETPOLINE_MINIMAL_AMD]=09=3D "Vulnerable: Minimal AMD ASM r=
etpoline",
 =09[SPECTRE_V2_RETPOLINE_GENERIC]=09=09=3D "Mitigation: Full generic retpo=
line",
 =09[SPECTRE_V2_RETPOLINE_AMD]=09=09=3D "Mitigation: Full AMD retpoline",
 =09[SPECTRE_V2_IBRS_ENHANCED]=09=09=3D "Mitigation: Enhanced IBRS",
@@ -250,11 +248,6 @@ static void __init spec2_print_if_secure(const char *r=
eason)
 =09=09pr_info("%s selected on command line.\n", reason);
 }
=20
-static inline bool retp_compiler(void)
-{
-=09return __is_defined(CONFIG_RETPOLINE);
-}
-
 static inline bool match_option(const char *arg, int arglen, const char *o=
pt)
 {
 =09int len =3D strlen(opt);
@@ -417,14 +410,12 @@ static void __init spectre_v2_select_mitigation(void)
 =09=09=09pr_err("Spectre mitigation: LFENCE not serializing, switching to =
generic retpoline\n");
 =09=09=09goto retpoline_generic;
 =09=09}
-=09=09mode =3D retp_compiler() ? SPECTRE_V2_RETPOLINE_AMD :
-=09=09=09=09=09 SPECTRE_V2_RETPOLINE_MINIMAL_AMD;
+=09=09mode =3D SPECTRE_V2_RETPOLINE_AMD;
 =09=09setup_force_cpu_cap(X86_FEATURE_RETPOLINE_AMD);
 =09=09setup_force_cpu_cap(X86_FEATURE_RETPOLINE);
 =09} else {
 =09retpoline_generic:
-=09=09mode =3D retp_compiler() ? SPECTRE_V2_RETPOLINE_GENERIC :
-=09=09=09=09=09 SPECTRE_V2_RETPOLINE_MINIMAL;
+=09=09mode =3D SPECTRE_V2_RETPOLINE_GENERIC;
 =09=09setup_force_cpu_cap(X86_FEATURE_RETPOLINE);
 =09}
=20
--=20
1.8.3.1