• Martin Schwidefsky's avatar
    [S390] fix system call parameter functions. · 59da2139
    Martin Schwidefsky authored
    syscall_get_nr() currently returns a valid result only if the call
    chain of the traced process includes do_syscall_trace_enter(). But
    collect_syscall() can be called for any sleeping task, the result of
    syscall_get_nr() in general is completely bogus.
    To make syscall_get_nr() work for any sleeping task the traps field
    in pt_regs is replace with svcnr - the system call number the process
    is executing. If svcnr == 0 the process is not on a system call path.
    The syscall_get_arguments and syscall_set_arguments use regs->gprs[2]
    for the first system call parameter. This is incorrect since gprs[2]
    may have been overwritten with the system call number if the call
    chain includes do_syscall_trace_enter. Use regs->orig_gprs2 instead.
    Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>