From: Ben Hutchings <ben@decadent.org.uk>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>,
Zhenzhong Duan <zhenzhong.duan@oracle.com>,
Thomas Gleixner <tglx@linutronix.de>,
David Woodhouse <dwmw@amazon.co.uk>, Borislav Petkov <bp@suse.de>,
Daniel Borkmann <daniel@iogearbox.net>,
"H. Peter Anvin" <hpa@zytor.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Andy Lutomirski <luto@kernel.org>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
Michal Marek <michal.lkml@markovi.net>,
srinivas.eeda@oracle.com
Subject: Re: [PATCH 4.9 02/24] x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support
Date: Wed, 09 Mar 2022 20:58:06 +0100 [thread overview]
Message-ID: <ab991a7ac7215fa18ba83698df2450c1c2ded334.camel@decadent.org.uk> (raw)
In-Reply-To: <20220309155856.369868546@linuxfoundation.org>
[-- Attachment #1.1: Type: text/plain, Size: 781 bytes --]
On Wed, 2022-03-09 at 16:59 +0100, Greg Kroah-Hartman wrote:
> From: Zhenzhong Duan <zhenzhong.duan@oracle.com>
>
> commit 4cd24de3a0980bf3100c9dcb08ef65ca7c31af48 upstream.
[...]
Sorry, there are a couple of fixes needed on top of this:
commit 25896d073d8a0403b07e6dec56f58e6c33678207
Author: Masahiro Yamada <yamada.masahiro@socionext.com>
Date: Wed Dec 5 15:27:19 2018 +0900
x86/build: Fix compiler support check for CONFIG_RETPOLINE
commit e4f358916d528d479c3c12bd2fd03f2d5a576380
Author: WANG Chao <chao.wang@ucloud.cn>
Date: Tue Dec 11 00:37:25 2018 +0800
x86, modpost: Replace last remnants of RETPOLINE with CONFIG_RETPOLINE
I've attached my backports of those.
Ben.
--
Ben Hutchings
73.46% of all statistics are made up.
[-- Attachment #1.2: 0001-x86-build-Fix-compiler-support-check-for-CONFIG_RETP.patch --]
[-- Type: text/x-patch, Size: 2545 bytes --]
From 37cd19b0e1e70592d3d547360bf979f69514f3c1 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <yamada.masahiro@socionext.com>
Date: Wed, 5 Dec 2018 15:27:19 +0900
Subject: [PATCH 1/2] x86/build: Fix compiler support check for
CONFIG_RETPOLINE
commit 25896d073d8a0403b07e6dec56f58e6c33678207 upstream.
It is troublesome to add a diagnostic like this to the Makefile
parse stage because the top-level Makefile could be parsed with
a stale include/config/auto.conf.
Once you are hit by the error about non-retpoline compiler, the
compilation still breaks even after disabling CONFIG_RETPOLINE.
The easiest fix is to move this check to the "archprepare" like
this commit did:
829fe4aa9ac1 ("x86: Allow generating user-space headers without a compiler")
Reported-by: Meelis Roos <mroos@linux.ee>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Fixes: 4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support")
Link: http://lkml.kernel.org/r/1543991239-18476-1-git-send-email-yamada.masahiro@socionext.com
Link: https://lkml.org/lkml/2018/12/4/206
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/x86/Makefile | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index a69cfa33f986..a77737a979c8 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -221,9 +221,6 @@ ifdef CONFIG_RETPOLINE
RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
RETPOLINE_CFLAGS += $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
- ifeq ($(RETPOLINE_CFLAGS),)
- $(error You are building kernel with non-retpoline compiler, please update your compiler.)
- endif
KBUILD_CFLAGS += $(RETPOLINE_CFLAGS)
endif
@@ -240,6 +237,13 @@ archscripts: scripts_basic
ifeq ($(CONFIG_KEXEC_FILE),y)
$(Q)$(MAKE) $(build)=arch/x86/purgatory arch/x86/purgatory/kexec-purgatory.c
endif
+ifdef CONFIG_RETPOLINE
+ifeq ($(RETPOLINE_CFLAGS),)
+ @echo "You are building kernel with non-retpoline compiler." >&2
+ @echo "Please update your compiler." >&2
+ @false
+endif
+endif
###
# Kernel objects
[-- Attachment #1.3: 0002-x86-modpost-Replace-last-remnants-of-RETPOLINE-with-.patch --]
[-- Type: text/x-patch, Size: 3971 bytes --]
From 7e95e29eb541a62d50df01c8c52f3d75d13a6bec Mon Sep 17 00:00:00 2001
From: WANG Chao <chao.wang@ucloud.cn>
Date: Tue, 11 Dec 2018 00:37:25 +0800
Subject: [PATCH 2/2] x86, modpost: Replace last remnants of RETPOLINE with
CONFIG_RETPOLINE
commit e4f358916d528d479c3c12bd2fd03f2d5a576380 upstream.
Commit
4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support")
replaced the RETPOLINE define with CONFIG_RETPOLINE checks. Remove the
remaining pieces.
[ bp: Massage commit message. ]
Fixes: 4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support")
Signed-off-by: WANG Chao <chao.wang@ucloud.cn>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Kees Cook <keescook@chromium.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: linux-kbuild@vger.kernel.org
Cc: srinivas.eeda@oracle.com
Cc: stable <stable@vger.kernel.org>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20181210163725.95977-1-chao.wang@ucloud.cn
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/x86/kernel/cpu/bugs.c | 2 +-
include/linux/compiler-gcc.h | 2 +-
include/linux/module.h | 2 +-
scripts/mod/modpost.c | 2 +-
4 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 20b330902e54..94aa0206b1f9 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -586,7 +586,7 @@ static enum spectre_v2_user_mitigation spectre_v2_user_stibp __ro_after_init =
static enum spectre_v2_user_mitigation spectre_v2_user_ibpb __ro_after_init =
SPECTRE_V2_USER_NONE;
-#ifdef RETPOLINE
+#ifdef CONFIG_RETPOLINE
static bool spectre_v2_bad_module;
bool retpoline_module_ok(bool has_retpoline)
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index d830eddacdc6..1c1ca4168516 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -107,7 +107,7 @@
#define __weak __attribute__((weak))
#define __alias(symbol) __attribute__((alias(#symbol)))
-#ifdef RETPOLINE
+#ifdef CONFIG_RETPOLINE
#define __noretpoline __attribute__((indirect_branch("keep")))
#endif
diff --git a/include/linux/module.h b/include/linux/module.h
index 99f330ae13da..be4a3a9fd89c 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -791,7 +791,7 @@ static inline void module_bug_finalize(const Elf_Ehdr *hdr,
static inline void module_bug_cleanup(struct module *mod) {}
#endif /* CONFIG_GENERIC_BUG */
-#ifdef RETPOLINE
+#ifdef CONFIG_RETPOLINE
extern bool retpoline_module_ok(bool has_retpoline);
#else
static inline bool retpoline_module_ok(bool has_retpoline)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 9abcdf2e8dfe..62b0552b7b71 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -2147,7 +2147,7 @@ static void add_intree_flag(struct buffer *b, int is_intree)
/* Cannot check for assembler */
static void add_retpoline(struct buffer *b)
{
- buf_printf(b, "\n#ifdef RETPOLINE\n");
+ buf_printf(b, "\n#ifdef CONFIG_RETPOLINE\n");
buf_printf(b, "MODULE_INFO(retpoline, \"Y\");\n");
buf_printf(b, "#endif\n");
}
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next prev parent reply other threads:[~2022-03-09 19:58 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-09 15:59 [PATCH 4.9 00/24] 4.9.306-rc1 review Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 01/24] x86/speculation: Add RETPOLINE_AMD support to the inline asm CALL_NOSPEC variant Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 02/24] x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support Greg Kroah-Hartman
2022-03-09 19:58 ` Ben Hutchings [this message]
2022-03-09 22:39 ` Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 03/24] x86/retpoline: Remove minimal retpoline support Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 04/24] Documentation: Add section about CPU vulnerabilities for Spectre Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 05/24] Documentation: Add swapgs description to the Spectre v1 documentation Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 06/24] Documentation: refer to config RANDOMIZE_BASE for kernel address-space randomization Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 07/24] x86/speculation: Merge one test in spectre_v2_user_select_mitigation() Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 08/24] x86,bugs: Unconditionally allow spectre_v2=retpoline,amd Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 09/24] x86/speculation: Rename RETPOLINE_AMD to RETPOLINE_LFENCE Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 10/24] x86/speculation: Add eIBRS + Retpoline options Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 11/24] Documentation/hw-vuln: Update spectre doc Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 12/24] x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation reporting Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 13/24] x86/speculation: Use generic retpoline by default on AMD Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 14/24] x86/speculation: Update link to AMD speculation whitepaper Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 15/24] x86/speculation: Warn about Spectre v2 LFENCE mitigation Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 16/24] x86/speculation: Warn about eIBRS + LFENCE + Unprivileged eBPF + SMT Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 17/24] arm/arm64: Provide a wrapper for SMCCC 1.1 calls Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 18/24] arm/arm64: smccc/psci: add arm_smccc_1_1_get_conduit() Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 19/24] ARM: report Spectre v2 status through sysfs Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 20/24] ARM: early traps initialisation Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 21/24] ARM: use LOADADDR() to get load address of sections Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 22/24] ARM: Spectre-BHB workaround Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 23/24] ARM: include unprivileged BPF status in Spectre V2 reporting Greg Kroah-Hartman
2022-03-09 15:59 ` [PATCH 4.9 24/24] ARM: fix build error when BPF_SYSCALL is disabled Greg Kroah-Hartman
2022-03-09 18:40 ` [PATCH 4.9 00/24] 4.9.306-rc1 review Daniel Díaz
2022-03-09 19:18 ` Daniel Díaz
2022-03-10 3:32 ` Florian Fainelli
2022-03-10 11:41 ` Pavel Machek
2022-03-10 11:48 ` Greg Kroah-Hartman
2022-03-09 20:26 ` Shuah Khan
2022-03-10 3:45 ` Florian Fainelli
2022-03-10 11:39 ` Pavel Machek
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