CPU mitigations config entries are inconsistent, and names are hard to
related[1]. There are concrete benefits for both users and developers of
having all the mitigation config options living in the same config
namespace.
The mitigation options should have consistency and start with
MITIGATION.
Rename the Kconfig entry from GDS_FORCE_MITIGATION to
MITIGATION_GDS_FORCE.
[1] Link: https://lore.kernel.org/lkml/20231011044252.42bplzjsam3qsasz@treble/
Suggested-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Breno Leitao <[email protected]>
---
arch/x86/Kconfig | 2 +-
arch/x86/kernel/cpu/bugs.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 3762f41bb092..ddf0d8bc6db9 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2590,7 +2590,7 @@ config SLS
against straight line speculation. The kernel image might be slightly
larger.
-config GDS_FORCE_MITIGATION
+config MITIGATION_GDS_FORCE
bool "Force GDS Mitigation"
depends on CPU_SUP_INTEL
default n
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index bb0ab8466b91..3c7e27b58f0e 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -671,7 +671,7 @@ enum gds_mitigations {
GDS_MITIGATION_HYPERVISOR,
};
-#if IS_ENABLED(CONFIG_GDS_FORCE_MITIGATION)
+#if IS_ENABLED(CONFIG_MITIGATION_GDS_FORCE)
static enum gds_mitigations gds_mitigation __ro_after_init = GDS_MITIGATION_FORCE;
#else
static enum gds_mitigations gds_mitigation __ro_after_init = GDS_MITIGATION_FULL;
--
2.34.1
The following commit has been merged into the x86/bugs branch of tip:
Commit-ID: be83e809ca67bca98fde97ad6b9344237963220b
Gitweb: https://git.kernel.org/tip/be83e809ca67bca98fde97ad6b9344237963220b
Author: Breno Leitao <[email protected]>
AuthorDate: Tue, 21 Nov 2023 08:07:28 -08:00
Committer: Ingo Molnar <[email protected]>
CommitterDate: Wed, 10 Jan 2024 10:43:14 +01:00
x86/bugs: Rename CONFIG_GDS_FORCE_MITIGATION => CONFIG_MITIGATION_GDS_FORCE
So the CPU mitigations Kconfig entries - there's 10 meanwhile - are named
in a historically idiosyncratic and hence rather inconsistent fashion
and have become hard to relate with each other over the years:
https://lore.kernel.org/lkml/20231011044252.42bplzjsam3qsasz@treble/
When they were introduced we never expected that we'd eventually have
about a dozen of them, and that more organization would be useful,
especially for Linux distributions that want to enable them in an
informed fashion, and want to make sure all mitigations are configured
as expected.
For example, the current CONFIG_SPECULATION_MITIGATIONS namespace is only
halfway populated, where some mitigations have entries in Kconfig, and
they could be modified, while others mitigations do not have Kconfig entries,
and can not be controlled at build time.
Fine-grained control over these Kconfig entries can help in a number of ways:
1) Users can choose and pick only mitigations that are important for
their workloads.
2) Users and developers can choose to disable mitigations that mangle
the assembly code generation, making it hard to read.
3) Separate Kconfigs for just source code readability,
so that we see *which* butt-ugly piece of crap code is for what
reason...
In most cases, if a mitigation is disabled at compilation time, it
can still be enabled at runtime using kernel command line arguments.
This is the first patch of an initial series that renames various
mitigation related Kconfig options, unifying them under a single
CONFIG_MITIGATION_* namespace:
CONFIG_GDS_FORCE_MITIGATION => CONFIG_MITIGATION_GDS_FORCE
CONFIG_CPU_IBPB_ENTRY => CONFIG_MITIGATION_IBPB_ENTRY
CONFIG_CALL_DEPTH_TRACKING => CONFIG_MITIGATION_CALL_DEPTH_TRACKING
CONFIG_PAGE_TABLE_ISOLATION => CONFIG_MITIGATION_PAGE_TABLE_ISOLATION
CONFIG_RETPOLINE => CONFIG_MITIGATION_RETPOLINE
CONFIG_SLS => CONFIG_MITIGATION_SLS
CONFIG_CPU_UNRET_ENTRY => CONFIG_MITIGATION_UNRET_ENTRY
CONFIG_CPU_IBRS_ENTRY => CONFIG_MITIGATION_IBRS_ENTRY
CONFIG_CPU_SRSO => CONFIG_MITIGATION_SRSO
CONFIG_RETHUNK => CONFIG_MITIGATION_RETHUNK
Implement step 1/10 of the namespace unification of CPU mitigations related
Kconfig options and rename CONFIG_GDS_FORCE_MITIGATION to
CONFIG_MITIGATION_GDS_FORCE.
[ mingo: Rewrote changelog for clarity. ]
Suggested-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Breno Leitao <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
---
arch/x86/Kconfig | 2 +-
arch/x86/kernel/cpu/bugs.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 53f2e77..1dba33a 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2587,7 +2587,7 @@ config SLS
against straight line speculation. The kernel image might be slightly
larger.
-config GDS_FORCE_MITIGATION
+config MITIGATION_GDS_FORCE
bool "Force GDS Mitigation"
depends on CPU_SUP_INTEL
default n
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index bb0ab84..3c7e27b 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -671,7 +671,7 @@ enum gds_mitigations {
GDS_MITIGATION_HYPERVISOR,
};
-#if IS_ENABLED(CONFIG_GDS_FORCE_MITIGATION)
+#if IS_ENABLED(CONFIG_MITIGATION_GDS_FORCE)
static enum gds_mitigations gds_mitigation __ro_after_init = GDS_MITIGATION_FORCE;
#else
static enum gds_mitigations gds_mitigation __ro_after_init = GDS_MITIGATION_FULL;