diff options
| -rw-r--r-- | arch/i386/kernel/entry.S | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S index fba0dc7abd48..b0c2e80f59f1 100644 --- a/arch/i386/kernel/entry.S +++ b/arch/i386/kernel/entry.S @@ -66,7 +66,9 @@ OLDESP = 0x34 OLDSS = 0x38 CF_MASK = 0x00000001 +TF_MASK = 0x00000100 IF_MASK = 0x00000200 +DF_MASK = 0x00000400 NT_MASK = 0x00004000 VM_MASK = 0x00020000 @@ -134,6 +136,17 @@ ENTRY(lcall7) movl %eax,EFLAGS(%esp) # movl %edx,EIP(%esp) # Now we move them to their "normal" places movl %ecx,CS(%esp) # + + # + # Call gates don't clear TF and NT in eflags like + # traps do, so we need to do it ourselves. + # %eax already contains eflags (but it may have + # DF set, clear that also) + # + andl $~(DF_MASK | TF_MASK | NT_MASK),%eax + pushl %eax + popfl + movl %esp, %ebx pushl %ebx andl $-8192, %ebx # GET_THREAD_INFO @@ -156,6 +169,17 @@ ENTRY(lcall27) movl %eax,EFLAGS(%esp) # movl %edx,EIP(%esp) # Now we move them to their "normal" places movl %ecx,CS(%esp) # + + # + # Call gates don't clear TF and NT in eflags like + # traps do, so we need to do it ourselves. + # %eax already contains eflags (but it may have + # DF set, clear that also) + # + andl $~(DF_MASK | TF_MASK | NT_MASK),%eax + pushl %eax + popfl + movl %esp, %ebx pushl %ebx andl $-8192, %ebx # GET_THREAD_INFO |