Re: Regression fix for bpf in v5.3 (was Re: [RFC PATCH] bpf: handle 32-bit zext during constant blinding)

2019-08-21 Thread Naveen N. Rao
Jiong Wang wrote: Michael Ellerman writes: "Naveen N. Rao" writes: Since BPF constant blinding is performed after the verifier pass, there are certain ALU32 instructions inserted which don't have a corresponding zext instruction inserted after. This is causing a kernel oops on powerpc and ca

Re: Regression fix for bpf in v5.3 (was Re: [RFC PATCH] bpf: handle 32-bit zext during constant blinding)

2019-08-21 Thread Jiong Wang
Michael Ellerman writes: > "Naveen N. Rao" writes: >> Since BPF constant blinding is performed after the verifier pass, there >> are certain ALU32 instructions inserted which don't have a corresponding >> zext instruction inserted after. This is causing a kernel oops on >> powerpc and can be re

Regression fix for bpf in v5.3 (was Re: [RFC PATCH] bpf: handle 32-bit zext during constant blinding)

2019-08-21 Thread Michael Ellerman
"Naveen N. Rao" writes: > Since BPF constant blinding is performed after the verifier pass, there > are certain ALU32 instructions inserted which don't have a corresponding > zext instruction inserted after. This is causing a kernel oops on > powerpc and can be reproduced by running 'test_cgroup_s

Re: [RFC PATCH] bpf: handle 32-bit zext during constant blinding

2019-08-21 Thread Jiong Wang
Naveen N. Rao writes: > Naveen N. Rao wrote: >> Since BPF constant blinding is performed after the verifier pass, there >> are certain ALU32 instructions inserted which don't have a corresponding >> zext instruction inserted after. This is causing a kernel oops on >> powerpc and can be reproduce

Re: [RFC PATCH] bpf: handle 32-bit zext during constant blinding

2019-08-21 Thread Naveen N. Rao
Naveen N. Rao wrote: Since BPF constant blinding is performed after the verifier pass, there are certain ALU32 instructions inserted which don't have a corresponding zext instruction inserted after. This is causing a kernel oops on powerpc and can be reproduced by running 'test_cgroup_storage' wi

[RFC PATCH] bpf: handle 32-bit zext during constant blinding

2019-08-13 Thread Naveen N. Rao
Since BPF constant blinding is performed after the verifier pass, there are certain ALU32 instructions inserted which don't have a corresponding zext instruction inserted after. This is causing a kernel oops on powerpc and can be reproduced by running 'test_cgroup_storage' with bpf_jit_harden=2. F