subject:"\[PATCH net\] bpf, arm64\: use separate register for state in stxr"

Re: [PATCH net] bpf, arm64: use separate register for state in stxr

2017-06-07 Thread David Miller

From: Daniel Borkmann Date: Wed, 7 Jun 2017 13:45:37 +0200 > Will reported that in BPF_XADD we must use a different register in stxr > instruction for the status flag due to otherwise CONSTRAINED UNPREDICTABLE > behavior per architecture. Reference manual says [1]: > > If s == t, then one of

Re: [PATCH net] bpf, arm64: use separate register for state in stxr

2017-06-07 Thread Will Deacon

Hi Daniel, On Wed, Jun 07, 2017 at 01:45:37PM +0200, Daniel Borkmann wrote: > Will reported that in BPF_XADD we must use a different register in stxr > instruction for the status flag due to otherwise CONSTRAINED UNPREDICTABLE > behavior per architecture. Reference manual says [1]: > > If s ==

[PATCH net] bpf, arm64: use separate register for state in stxr

2017-06-07 Thread Daniel Borkmann

Will reported that in BPF_XADD we must use a different register in stxr instruction for the status flag due to otherwise CONSTRAINED UNPREDICTABLE behavior per architecture. Reference manual says [1]: If s == t, then one of the following behaviors must occur: * The instruction is UNDEFINED.