Re: [RFC][PATCH 1/2] x86: Allow breakpoints to emulate call functions

[Andy Lutomirski]

> On May 2, 2019, at 12:28 PM, Jiri Kosina <ji...@kernel.org> wrote:
> 
>> On Thu, 2 May 2019, Linus Torvalds wrote:
>> 
>> I forget: is #BP _only_ for the "int3" instruction? 
> 
> Hmm, according to 17.3.2 in vol 3 of SDM (and table 6-1 there), that 
> indeed seems to be the case, so we should be fine.

I’m reasonably confident that the absurd MOV SS; INT3 sequence results in #BP 
from user mode and then #DB inside that (as opposed to vice versa), so this 
should be okay.