[PATCH v6 02/13] x86/bugs: Rename CPU_IBPB_ENTRY to MITIGATION_IBPB_ENTRY

From: Breno Leitao
Date: Tue Nov 21 2023 - 12:10:01 EST


CPU mitigations config entries are inconsistent, and names are hard to
related. 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 CPU_IBPB_ENTRY to MITIGATION_IBPB_ENTRY.

Suggested-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
---
arch/x86/Kconfig | 2 +-
arch/x86/include/asm/nospec-branch.h | 2 +-
arch/x86/kernel/cpu/bugs.c | 11 ++++++-----
3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index ddf0d8bc6db9..2e16ab138a1c 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2557,7 +2557,7 @@ config CALL_THUNKS_DEBUG
Only enable this when you are debugging call thunks as this
creates a noticeable runtime overhead. If unsure say N.

-config CPU_IBPB_ENTRY
+config MITIGATION_IBPB_ENTRY
bool "Enable IBPB on kernel entry"
depends on CPU_SUP_AMD && X86_64
default y
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index f93e9b96927a..0676b077207c 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -289,7 +289,7 @@
* where we have a stack but before any RET instruction.
*/
.macro __UNTRAIN_RET ibpb_feature, call_depth_insns
-#if defined(CONFIG_RETHUNK) || defined(CONFIG_CPU_IBPB_ENTRY)
+#if defined(CONFIG_RETHUNK) || defined(CONFIG_MITIGATION_IBPB_ENTRY)
VALIDATE_UNRET_END
ALTERNATIVE_3 "", \
CALL_UNTRAIN_RET, X86_FEATURE_UNRET, \
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 3c7e27b58f0e..1de4791091ca 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -994,10 +994,10 @@ static void __init retbleed_select_mitigation(void)
if (!boot_cpu_has(X86_FEATURE_IBPB)) {
pr_err("WARNING: CPU does not support IBPB.\n");
goto do_cmd_auto;
- } else if (IS_ENABLED(CONFIG_CPU_IBPB_ENTRY)) {
+ } else if (IS_ENABLED(CONFIG_MITIGATION_IBPB_ENTRY)) {
retbleed_mitigation = RETBLEED_MITIGATION_IBPB;
} else {
- pr_err("WARNING: kernel not compiled with CPU_IBPB_ENTRY.\n");
+ pr_err("WARNING: kernel not compiled with MITIGATION_IBPB_ENTRY.\n");
goto do_cmd_auto;
}
break;
@@ -1023,7 +1023,8 @@ static void __init retbleed_select_mitigation(void)
boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {
if (IS_ENABLED(CONFIG_CPU_UNRET_ENTRY))
retbleed_mitigation = RETBLEED_MITIGATION_UNRET;
- else if (IS_ENABLED(CONFIG_CPU_IBPB_ENTRY) && boot_cpu_has(X86_FEATURE_IBPB))
+ else if (IS_ENABLED(CONFIG_MITIGATION_IBPB_ENTRY) &&
+ boot_cpu_has(X86_FEATURE_IBPB))
retbleed_mitigation = RETBLEED_MITIGATION_IBPB;
}

@@ -2482,13 +2483,13 @@ static void __init srso_select_mitigation(void)
break;

case SRSO_CMD_IBPB:
- if (IS_ENABLED(CONFIG_CPU_IBPB_ENTRY)) {
+ if (IS_ENABLED(CONFIG_MITIGATION_IBPB_ENTRY)) {
if (has_microcode) {
setup_force_cpu_cap(X86_FEATURE_ENTRY_IBPB);
srso_mitigation = SRSO_MITIGATION_IBPB;
}
} else {
- pr_err("WARNING: kernel not compiled with CPU_IBPB_ENTRY.\n");
+ pr_err("WARNING: kernel not compiled with MITIGATION_IBPB_ENTRY.\n");
}
break;

--
2.34.1