diff options
| author | Borislav Petkov (AMD) <bp@alien8.de> | 2024-03-28 15:59:05 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-04-10 17:28:26 +0300 |
| commit | 23178ec5abbdecfdd67eca17f3494f7c6ca0d925 (patch) | |
| tree | a4bc33c75aaaa0444b1ce986b8bb1ecc6c5edac9 /arch/x86/lib | |
| parent | 2eeab8c47c3c0276e0746bc382f405c9a236a5ad (diff) | |
| download | linux-23178ec5abbdecfdd67eca17f3494f7c6ca0d925.tar.xz | |
x86/bugs: Fix the SRSO mitigation on Zen3/4
commit 4535e1a4174c4111d92c5a9a21e542d232e0fcaa upstream.
The original version of the mitigation would patch in the calls to the
untraining routines directly. That is, the alternative() in UNTRAIN_RET
will patch in the CALL to srso_alias_untrain_ret() directly.
However, even if commit e7c25c441e9e ("x86/cpu: Cleanup the untrain
mess") meant well in trying to clean up the situation, due to micro-
architectural reasons, the untraining routine srso_alias_untrain_ret()
must be the target of a CALL instruction and not of a JMP instruction as
it is done now.
Reshuffle the alternative macros to accomplish that.
Fixes: e7c25c441e9e ("x86/cpu: Cleanup the untrain mess")
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/lib')
| -rw-r--r-- | arch/x86/lib/retpoline.S | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/arch/x86/lib/retpoline.S b/arch/x86/lib/retpoline.S index 65c5c44f006b..24c850e1e239 100644 --- a/arch/x86/lib/retpoline.S +++ b/arch/x86/lib/retpoline.S @@ -252,9 +252,7 @@ SYM_CODE_START(srso_return_thunk) SYM_CODE_END(srso_return_thunk) SYM_FUNC_START(entry_untrain_ret) - ALTERNATIVE_2 "jmp retbleed_untrain_ret", \ - "jmp srso_untrain_ret", X86_FEATURE_SRSO, \ - "jmp srso_alias_untrain_ret", X86_FEATURE_SRSO_ALIAS + ALTERNATIVE "jmp retbleed_untrain_ret", "jmp srso_untrain_ret", X86_FEATURE_SRSO SYM_FUNC_END(entry_untrain_ret) __EXPORT_THUNK(entry_untrain_ret) |