On Wed, Jul 29, 2015 at 1:16 PM, Linus Torvalds <torva...@linux-foundation.org> wrote: > On Wed, Jul 29, 2015 at 10:14 AM, Brian Gerst <brge...@gmail.com> wrote: >> >> I think it was causing signal handling to fail, but I can't remember >> exactly. > > Ugh. > > If that hunk made a difference, then there is something wrong with > your patch-series. So please double-check. > > Linus
I think I remember now what the issue was. Since entering vm86 mode uses force_iret(), the work_pending code path was being taken. I had to move the call to save_v86_state out of here to handle_signal(), otherwise it would just restore the 32-bit regs and exit the syscall without ever entering vm86 mode. But that meant that the test for kernel CS was seeing the vm86 regs instead of 32-bit regs, and was failing because it didn't account for the VM bit (if the real-mode CS looked like RPL 0). A fault would get stuck in a loop because it couldn't exit to the signal handling code. -- Brian Gerst -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
