[PATCH 6.1 64/69] x86/bugs: Replace CONFIG_SPECTRE_BHI_{ON,OFF} with CONFIG_MITIGATION_SPECTRE_BHI

Greg Kroah-Hartman
2024-04-15T14:41:32Z

From: Josh Poimboeuf <jpoimboe@kernel.org>

commit 4f511739c54b549061993b53fc0380f48dfca23b upstream.

For consistency with the other CONFIG_MITIGATION_* options, replace the
CONFIG_SPECTRE_BHI_{ON,OFF} options with a single
CONFIG_MITIGATION_SPECTRE_BHI option.

[ mingo: Fix ]

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nikolay Borisov <nik.borisov@suse.com>
Link: https://lore.kernel.org/r/3833812ea63e7fdbe36bf8b932e63f70d18e2a2a.1712813475.git.jpoimboe@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/Kconfig | 17 +++--------------
arch/x86/kernel/cpu/bugs.c | 2 +-
2 files changed, 4 insertions(+), 15 deletions(-)

--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2563,27 +2563,16 @@ config MITIGATION_RFDS
stored in floating point, vector and integer registers.
See also <file:Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst>

-choice
- prompt "Clear branch history"
+config MITIGATION_SPECTRE_BHI
+ bool "Mitigate Spectre-BHB (Branch History Injection)"
depends on CPU_SUP_INTEL
- default SPECTRE_BHI_ON
+ default y
help
Enable BHI mitigations. BHI attacks are a form of Spectre V2 attacks
where the branch history buffer is poisoned to speculatively steer
indirect branches.
See <file:Documentation/admin-guide/hw-vuln/spectre.rst>

-config SPECTRE_BHI_ON
- bool "on"
- help
- Equivalent to setting spectre_bhi=on command line parameter.
-config SPECTRE_BHI_OFF
- bool "off"
- help
- Equivalent to setting spectre_bhi=off command line parameter.
-
-endchoice
-
endif

config ARCH_HAS_ADD_PAGES
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -1605,7 +1605,7 @@ enum bhi_mitigations {
};

static enum bhi_mitigations bhi_mitigation __ro_after_init =
- IS_ENABLED(CONFIG_SPECTRE_BHI_ON) ? BHI_MITIGATION_ON : BHI_MITIGATION_OFF;
+ IS_ENABLED(CONFIG_MITIGATION_SPECTRE_BHI) ? BHI_MITIGATION_ON : BHI_MITIGATION_OFF;

static int __init spectre_bhi_parse_cmdline(char *str)
{