From: Josh Poimboeuf <jpoimboe@kernel.org>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Daniel Sneddon <daniel.sneddon@linux.intel.com>,
Pawan Gupta <pawan.kumar.gupta@linux.intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Alexandre Chartre <alexandre.chartre@oracle.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Peter Zijlstra <peterz@infradead.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sean Christopherson <seanjc@google.com>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Nikolay Borisov <nik.borisov@suse.com>,
KP Singh <kpsingh@kernel.org>, Waiman Long <longman@redhat.com>,
Borislav Petkov <bp@alien8.de>, Ingo Molnar <mingo@kernel.org>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Michael Ellerman <mpe@ellerman.id.au>,
Geert Uytterhoeven <geert@linux-m68k.org>
Subject: [PATCH v4 2/5] cpu/speculation: Fix CPU mitigation defaults for !x86
Date: Fri, 19 Apr 2024 14:09:48 -0700 [thread overview]
Message-ID: <9d3c997264829d0e2b28718222724ae8f9e7d8b4.1713559768.git.jpoimboe@kernel.org> (raw)
In-Reply-To: <cover.1713559768.git.jpoimboe@kernel.org>
CPU speculative execution mitigations were inadvertently disabled on
non-x86 arches by the following commit:
f337a6a21e2f ("x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n")
Fix it by replacing CONFIG_SPECULATION_MITIGATIONS with a new generic
CONFIG_CPU_MITIGATIONS option and moving the x86-specific mitigations to
a separate menu which depends on CONFIG_CPU_MITIGATIONS.
Fixes: f337a6a21e2f ("x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Closes: https://lkml.kernel.org/r/20240413115324.53303a68%40canb.auug.org.au
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
arch/Kconfig | 10 ++++++++++
arch/x86/Kconfig | 15 +++------------
kernel/cpu.c | 4 ++--
3 files changed, 15 insertions(+), 14 deletions(-)
diff --git a/arch/Kconfig b/arch/Kconfig
index 9f066785bb71..5c96849eb957 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -11,6 +11,16 @@ source "arch/$(SRCARCH)/Kconfig"
menu "General architecture-dependent options"
+config CPU_MITIGATIONS
+ bool "Mitigations for CPU speculative execution vulnerabilities"
+ default y
+ help
+ Say Y here to enable mitigations for CPU speculative execution
+ vulnerabilities.
+
+ If you say N, all mitigations will be disabled. You really
+ should know what you are doing to say so.
+
config ARCH_HAS_SUBPAGE_FAULTS
bool
help
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 4474bf32d0a4..85a4d57bce1e 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2488,17 +2488,8 @@ config PREFIX_SYMBOLS
def_bool y
depends on CALL_PADDING && !CFI_CLANG
-menuconfig SPECULATION_MITIGATIONS
- bool "Mitigations for speculative execution vulnerabilities"
- default y
- help
- Say Y here to enable options which enable mitigations for
- speculative execution hardware vulnerabilities.
-
- If you say N, all mitigations will be disabled. You really
- should know what you are doing to say so.
-
-if SPECULATION_MITIGATIONS
+menu "CPU speculative execution mitigation defaults"
+ depends on CPU_MITIGATIONS
config MITIGATION_PAGE_TABLE_ISOLATION
bool "Remove the kernel mapping in user mode"
@@ -2643,7 +2634,7 @@ config MITIGATION_SPECTRE_BHI
indirect branches.
See <file:Documentation/admin-guide/hw-vuln/spectre.rst>
-endif
+endmenu
config ARCH_HAS_ADD_PAGES
def_bool y
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 07ad53b7f119..bb0ff275fb46 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -3207,8 +3207,8 @@ enum cpu_mitigations {
};
static enum cpu_mitigations cpu_mitigations __ro_after_init =
- IS_ENABLED(CONFIG_SPECULATION_MITIGATIONS) ? CPU_MITIGATIONS_AUTO :
- CPU_MITIGATIONS_OFF;
+ IS_ENABLED(CONFIG_CPU_MITIGATIONS) ? CPU_MITIGATIONS_AUTO :
+ CPU_MITIGATIONS_OFF;
static int __init mitigations_parse_cmdline(char *arg)
{
--
2.44.0
next prev parent reply other threads:[~2024-04-19 21:09 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-19 21:09 [PATCH 0/5] x86/bugs: more BHI fixes Josh Poimboeuf
2024-04-19 21:09 ` [PATCH v4 1/5] x86/bugs: Only harden syscalls when needed Josh Poimboeuf
2024-04-22 8:09 ` Yujie Liu
2024-05-07 5:17 ` Josh Poimboeuf
2024-05-20 5:21 ` Yujie Liu
2024-04-19 21:09 ` Josh Poimboeuf [this message]
2024-04-20 0:09 ` [PATCH v4 2/5] cpu/speculation: Fix CPU mitigation defaults for !x86 Sean Christopherson
2024-04-23 14:10 ` Sean Christopherson
2024-04-24 5:35 ` Josh Poimboeuf
2024-04-19 21:09 ` [PATCH v4 3/5] x86/syscall: Mark exit[_group] syscall handlers __noreturn Josh Poimboeuf
2024-04-20 13:58 ` Paul E. McKenney
2024-04-21 5:25 ` Josh Poimboeuf
2024-04-21 20:40 ` Paul McKenney
2024-04-21 21:47 ` Paul McKenney
2024-05-02 23:48 ` Paul McKenney
2024-05-03 15:38 ` Paul E. McKenney
2024-05-03 19:56 ` Josh Poimboeuf
2024-05-03 20:44 ` Josh Poimboeuf
2024-05-03 23:33 ` Paul E. McKenney
2024-05-03 23:48 ` Josh Poimboeuf
2024-05-04 16:48 ` Paul E. McKenney
2024-04-19 21:09 ` [PATCH v4 4/5] x86/bugs: Remove duplicate Spectre cmdline option descriptions Josh Poimboeuf
2024-04-19 21:09 ` [PATCH v4 5/5] x86/bugs: Add 'spectre_bhi=vmexit' cmdline option Josh Poimboeuf
2024-04-19 21:46 ` Josh Poimboeuf
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