diff options
Diffstat (limited to 'arch/x86/entry/entry_32.S')
| -rw-r--r-- | arch/x86/entry/entry_32.S | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index f83ca5aa8b77..99fad6fed03c 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -718,6 +718,11 @@ ENTRY(__switch_to_asm) pushl %ebx pushl %edi pushl %esi + /* + * Flags are saved to prevent AC leakage. This could go + * away if objtool would have 32bit support to verify + * the STAC/CLAC correctness. + */ pushfl /* switch stack */ @@ -740,8 +745,9 @@ ENTRY(__switch_to_asm) FILL_RETURN_BUFFER %ebx, RSB_CLEAR_LOOPS, X86_FEATURE_RSB_CTXSW #endif - /* restore callee-saved registers */ + /* Restore flags or the incoming task to restore AC state. */ popfl + /* restore callee-saved registers */ popl %esi popl %edi popl %ebx |