On Fri, Jun 30, 2017 at 8:55 AM, Josh Poimboeuf <jpoim...@redhat.com> wrote: > On Fri, Jun 30, 2017 at 08:44:40AM -0700, Andy Lutomirski wrote: >> > A few comments about the first patch: >> > >> > >> > https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git/commit/?h=x86/entry_irq_stack&id=3e2aa2102cc1c5e60d4a8637bff78d0478a55059 >> > >> > - It uses a '693:' label instead of '.Lirqs_off_\@:' >> >> Touché! >> >> > >> > - There's a comment I don't follow: >> > >> > "Anything that can interrupt us here without using IST must be >> > *extremely* careful to limit its stack usage." >> > >> > What specifically could interrupt there without using IST? >> >> #DB, later on in the series. I'll update the comment. >> >> > >> > - Since do_softirq_own_stack() is a callable function, I think it still >> > needs to save rbp. >> >> Whoops. >> >> > >> > - Why change the "jmp error_exit" to "ret" in >> > xen_do_hypervisor_callback()? >> >> To match the other change I made there. I removed both. > > One more thing I forgot to mention: if you could use r10 instead of r11, > that would be helpful because it means one less register undwarf needs > to know about. (It already deals with r10 because of GCC stack > realignment).
I'll let you figure that one out :) (Although I think I agree with hpa: why not let it support all regs? Or am I missing something still?) > > -- > Josh
