Sven Schnelle <svens@xxxxxxxxxxxxxx> writes:
> commit 8779e05ba8aa ("parisc: Fix ptrace check on syscall return")
> fixed testing of TI_FLAGS. This uncovered a bug in the test mask.
> syscall_restore_rfi is only used when the kernel needs to exit to
> usespace with single stepping via recovery counter enabled. The test
> however used _TIF_SYSCALL_TRACE_MASK, which includes a lot of bits
> that shouldn't be tested here.
>
> Fix this by using TIF_SINGLESTEP and TIF_BLOCKSTEP directly and
> remove those bits from TIF_SYSCALL_TRACE_MASK.
I think we need to have TIF_SINGLESTEP and TIF_BLOCKSTEP in
TIF_SYSCALL_TRACE_MASK otherwise do_syscall_trace_exit() isn't
called when leaving to userspace. I'll read the code a bit more
during the weekend and prepare a v2.
