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| author | Ben Hutchings <ben@decadent.org.uk> | 2022-07-23 17:22:47 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2022-07-23 18:45:11 +0200 |
| commit | b648ab487f31bc4c38941bc770ea97fe394304bb (patch) | |
| tree | 9731e6188db1d88ade89c18f31db30faba007bf9 | |
| parent | efc72a665a61fd48c462f5248a9e3dc991398ddd (diff) | |
| download | linux-b648ab487f31bc4c38941bc770ea97fe394304bb.tar.gz | |
x86/speculation: Make all RETbleed mitigations 64-bit only
The mitigations for RETBleed are currently ineffective on x86_32 since
entry_32.S does not use the required macros. However, for an x86_32
target, the kconfig symbols for them are still enabled by default and
/sys/devices/system/cpu/vulnerabilities/retbleed will wrongly report
that mitigations are in place.
Make all of these symbols depend on X86_64, and only enable RETHUNK by
default on X86_64.
Fixes: f43b9876e857 ("x86/retbleed: Add fine grained Kconfig knobs")
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/YtwSR3NNsWp1ohfV@decadent.org.uk
| -rw-r--r-- | arch/x86/Kconfig | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index e58798f636d474..1670a3fed263b5 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2473,7 +2473,7 @@ config RETHUNK bool "Enable return-thunks" depends on RETPOLINE && CC_HAS_RETURN_THUNK select OBJTOOL if HAVE_OBJTOOL - default y + default y if X86_64 help Compile the kernel with the return-thunks compiler option to guard against kernel-to-user data leaks by avoiding return speculation. @@ -2482,21 +2482,21 @@ config RETHUNK config CPU_UNRET_ENTRY bool "Enable UNRET on kernel entry" - depends on CPU_SUP_AMD && RETHUNK + depends on CPU_SUP_AMD && RETHUNK && X86_64 default y help Compile the kernel with support for the retbleed=unret mitigation. config CPU_IBPB_ENTRY bool "Enable IBPB on kernel entry" - depends on CPU_SUP_AMD + depends on CPU_SUP_AMD && X86_64 default y help Compile the kernel with support for the retbleed=ibpb mitigation. config CPU_IBRS_ENTRY bool "Enable IBRS on kernel entry" - depends on CPU_SUP_INTEL + depends on CPU_SUP_INTEL && X86_64 default y help Compile the kernel with support for the spectre_v2=ibrs mitigation. |