Re: [Xen-devel] [PATCH v7 3/5] livepatch: NOP if func->new_addr is zero.

2016-09-22 Thread Jan Beulich
>>> On 21.09.16 at 18:57, wrote: > The NOP functionality will NOP any of the code at > the 'old_addr' or at 'name' if the 'new_addr' is zero. > The purpose of this is to NOP out calls, such as: > > e8 <4-bytes-offset> > > (5 byte insn), or on ARM a 4 byte insn for branching. > > We need the EI

[Xen-devel] [PATCH v7 3/5] livepatch: NOP if func->new_addr is zero.

2016-09-21 Thread Konrad Rzeszutek Wilk
The NOP functionality will NOP any of the code at the 'old_addr' or at 'name' if the 'new_addr' is zero. The purpose of this is to NOP out calls, such as: e8 <4-bytes-offset> (5 byte insn), or on ARM a 4 byte insn for branching. We need the EIP of where we need to the NOP, and that can be provi