Re: Seccomp support for linux-m68k

[Michael Schmitz <schmitzmic@gmail.com>]

Hi Andreas,

On 26/07/20 11:03 PM, Andreas Schwab wrote:
> On Jul 26 2020, Michael Schmitz wrote:
>
> > No particular reason - I had seen testb used in the syscall entry code and
> Where?  That may be bugs.

Here:

ENTRY(ret_from_signal)
        movel   %curptr@(TASK_STACK),%a1
        tstb    %a1@(TINFO_FLAGS+2)
        jge     1f
        jbsr    syscall_trace_leave
1:      RESTORE_SWITCH_STACK
        addql   #4,%sp
....

and here:

ENTRY(system_call)
        SAVE_ALL_SYS

        GET_CURRENT(%d1)
        movel   %d1,%a1

        | save top of frame
        movel   %sp,%curptr@(TASK_THREAD+THREAD_ESP0)

        | syscall trace?
        tstb    %a1@(TINFO_FLAGS+2)
        jmi     do_trace_entry
        cmpl    #NR_syscalls,%d0
        jcc     badsys

....

plus when saving the FPU context on resume (the comment there suggests 
FPUs keep 8 bits of status that must be tested, so that should be OK).

Cheers,

    Michael

> Andreas.