Messages in this thread | ![/](/images/icornerl.gif) | | Date | Mon, 7 Mar 2016 18:05:32 +0100 (CET) | From | Jiri Kosina <> | Subject | Re: [PATCH] usbhid: Fix lockdep unannotated irqs-off warning |
| |
On Mon, 7 Mar 2016, Alan Stern wrote:
> > 319: 9c pushfq > > 31a: 41 5c pop %r12 > > 31c: 48 89 df mov %rbx,%rdi > > 31f: e8 00 00 00 00 callq 324 <usbhid_close+0x44> > > 324: 41 54 push %r12 > > 326: 9d popfq > > spin_unlock_irq(&usbhid->lock); while attempting to preserve the Z > flag. The problem is that this code sequence will also preserve the > Interrupt Flag!
You are right Alan, thanks a lot, for reason I could not understand I completely missed the pushf/popf last time I was looking at the generated assembly!
OK, a little bit of googling revealed related discussion on LLVM mailinglist:
http://lists.llvm.org/pipermail/llvm-dev/2015-July/088780.html
Seems like it has been reported already, but noone dared to fix it yet.
This basically makes LLVM unusable for compiling the kernel.
-- Jiri Kosina SUSE Labs
| ![\](/images/icornerr.gif) |