BMC/Intel-BMC/linux.git/arch/s390/net, branch v4.4

ebpf: migrate bpf_prog's flags to bitfield

2015-10-03T12:02:39+00:00

As we need to add further flags to the bpf_prog structure, lets migrate both bools to a bitfield representation. The size of the base structure (excluding insns) remains unchanged at 40 bytes. Add also tags for the kmemchecker, so that it doesn't throw false positives. Even in case gcc would generate suboptimal code, it's not being accessed in performance critical paths. Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller

bpf: s390: Fix build error caused by the struct bpf_array member name changed

2015-08-11T18:49:40+00:00

There is a build error that "'struct bpf_array' has no member named 'prog'" on s390. In commit 2a36f0b92eb6 ("bpf: Make the bpf_prog_array_map more generic"), the member 'prog' of struct bpf_array is replaced by 'ptrs'. So this patch fixes it. Fixes: 2a36f0b92eb6 ("bpf: Make the bpf_prog_array_map more generic") Reported-by: Wu Fengguang Signed-off-by: Kaixu Xia Signed-off-by: David S. Miller

bpf: provide helper that indicates eBPF was migrated

2015-07-30T18:13:20+00:00

During recent discussions we had with Michael, we found that it would be useful to have an indicator that tells the JIT that an eBPF program had been migrated from classic instructions into eBPF instructions, as only in that case A and X need to be cleared in the prologue. Such eBPF programs do not set a particular type, but all have BPF_PROG_TYPE_UNSPEC. Thus, introduce a small helper for cde66c2d88da ("s390/bpf: Only clear A and X for converted BPF programs") and possibly others in future. Signed-off-by: Daniel Borkmann Cc: Michael Holzheu Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller

s390/bpf: recache skb->data/hlen for skb_vlan_push/pop

2015-07-29T21:59:58+00:00

Allow eBPF programs attached to TC qdiscs call skb_vlan_push/pop via helper functions. These functions may change skb->data/hlen. This data is cached by s390 JIT to improve performance of ld_abs/ld_ind instructions. Therefore after a change we have to reload the data. In case of usage of skb_vlan_push/pop, in the prologue we store the SKB pointer on the stack and restore it after BPF_JMP_CALL to skb_vlan_push/pop. Signed-off-by: Michael Holzheu Signed-off-by: David S. Miller

s390/bpf: Only clear A and X for converted BPF programs

2015-07-29T21:59:58+00:00

Only classic BPF programs that have been converted to eBPF need to clear the A and X registers. We can check for converted programs with: bpf_prog->type == BPF_PROG_TYPE_UNSPEC So add the check and skip initialization for real eBPF programs. Signed-off-by: Michael Holzheu Signed-off-by: David S. Miller

s390/bpf: increase BPF_SIZE_MAX

2015-07-29T21:59:58+00:00

Currently we have the restriction that jitted BPF programs can have a maximum size of one page. The reason is that we use short displacements for the literal pool. The 20 bit displacements are available since z990 and BPF requires z196 as minimum. Therefore we can remove this restriction and use everywhere 20 bit signed long displacements. Acked-by: Martin Schwidefsky Signed-off-by: Michael Holzheu Signed-off-by: David S. Miller

s390/bpf: Fix multiple macro expansions

2015-07-29T21:59:58+00:00

The EMIT6_DISP_LH macro passes the "disp" parameter to the _EMIT6_DISP_LH macro. The _EMIT6_DISP_LH macro uses the "disp" parameter twice: unsigned int __disp_h = ((u32)disp) & 0xff000; unsigned int __disp_l = ((u32)disp) & 0x00fff; The EMIT6_DISP_LH is used several times with EMIT_CONST_U64() as "disp" parameter. Therefore always two constants are created per usage of EMIT6_DISP_LH. Fix this and add variable "_disp" to avoid multiple expansions. * v2: Move "_disp" to _EMIT6_DISP_LH as suggested by Joe Perches Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend") Signed-off-by: Michael Holzheu Signed-off-by: David S. Miller

s390/bpf: clear correct BPF accumulator register

2015-07-29T21:59:58+00:00

Currently we assumed the following BPF to eBPF register mapping: - BPF_REG_A -> BPF_REG_7 - BPF_REG_X -> BPF_REG_8 Unfortunately this mapping is wrong. The correct mapping is: - BPF_REG_A -> BPF_REG_0 - BPF_REG_X -> BPF_REG_7 So clear the correct registers and use the BPF_REG_A and BPF_REG_X macros instead of BPF_REG_0/7. Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend") Cc: stable@vger.kernel.org # 4.0+ Signed-off-by: Michael Holzheu Signed-off-by: David S. Miller

bpf: introduce bpf_skb_vlan_push/pop() helpers

2015-07-21T03:52:31+00:00

Allow eBPF programs attached to TC qdiscs call skb_vlan_push/pop via helper functions. These functions may change skb->data/hlen which are cached by some JITs to improve performance of ld_abs/ld_ind instructions. Therefore JITs need to recognize bpf_skb_vlan_push/pop() calls, re-compute header len and re-cache skb->data/hlen back into cpu registers. Note, skb->data/hlen are not directly accessible from the programs, so any changes to skb->data done either by these helpers or by other TC actions are safe. eBPF JIT supported by three architectures: - arm64 JIT is using bpf_load_pointer() without caching, so it's ok as-is. - x64 JIT re-caches skb->data/hlen unconditionally after vlan_push/pop calls (experiments showed that conditional re-caching is slower). - s390 JIT falls back to interpreter for now when bpf_skb_vlan_push() is present in the program (re-caching is tbd). These helpers allow more scalable handling of vlan from the programs. Instead of creating thousands of vlan netdevs on top of eth0 and attaching TC+ingress+bpf to all of them, the program can be attached to eth0 directly and manipulate vlans as necessary. Signed-off-by: Alexei Starovoitov Signed-off-by: David S. Miller

s390/bpf: Fix backward jumps

2015-06-25T07:39:18+00:00

Currently all backward jumps crash for JITed s390x eBPF programs with an illegal instruction program check and kernel panic. Because for negative values the opcode of the jump instruction is overriden by the negative branch offset an illegal instruction is generated by the JIT: 000003ff802da378: c01100000002 lgfi %r1,2 000003ff802da37e: fffffff52065 unknown <-- illegal instruction 000003ff802da384: b904002e lgr %r2,%r14 So fix this and mask the offset in order not to damage the opcode. Cc: stable@vger.kernel.org # 4.0+ Signed-off-by: Michael Holzheu Signed-off-by: Martin Schwidefsky