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2023-03-10s390/bpf: Add expoline to tail callsIlya Leoshkevich
[ Upstream commit bb4ef8fc3d193ed8d5583fb47cbeff5d8fb8302f ] All the indirect jumps in the eBPF JIT already use expolines, except for the tail call one. Fixes: de5cb6eb514e ("s390: use expoline thunks in the BPF JIT") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Link: https://lore.kernel.org/r/20230129190501.1624747-3-iii@linux.ibm.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-23s390/bpf: Fix typo in commentJulia Lawall
Spelling mistake (triple letters) in comment. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Link: https://lore.kernel.org/bpf/20220521111145.81697-84-Julia.Lawall@inria.fr
2022-03-10s390: raise minimum supported machine generation to z10Vasily Gorbik
Machine generations up to z9 (released in May 2006) have been officially out of service for several years now (z9 end of service - January 31, 2019). No distributions build kernels supporting those old machine generations anymore, except Debian, which seems to pick the oldest supported generation. The team supporting Debian on s390 has been notified about the change. Raising minimum supported machine generation to z10 helps to reduce maintenance cost and effectively remove code, which is not getting enough testing coverage due to lack of older hardware and distributions support. Besides that this unblocks some optimization opportunities and allows to use wider instruction set in asm files for future features implementation. Due to this change spectre mitigation and usercopy implementations could be drastically simplified and many newer instructions could be converted from ".insn" encoding to instruction names. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-08s390/bpf: encode register within extable entryHeiko Carstens
Instead of decoding the instruction that faulted to get the register which needs to be zeroed, simply encode its number into the extable entries during code generation. This allows to get rid of a bit of code, and is also what other architectures are doing. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-08s390/extable: convert to relative table with dataHeiko Carstens
Follow arm64, riscv, and x86 and change extable layout to common "relative table with data". This allows to get rid of s390 specific code in sorttable.c. The main difference to before is that extable entries do not contain a relative function pointer anymore. Instead data and type fields are added. The type field is used to indicate which exception handler needs to be called, while the data field is currently unused. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-08s390/extable: move EX_TABLE define to asm-extable.hHeiko Carstens
Follow arm64 and riscv and move the EX_TABLE define to asm-extable.h which is a lot less generic than the current linkage.h. Also make sure that all files which contain EX_TABLE usages actually include the new header file. This should make sure that the files always compile and there won't be any random compile breakage due to other header file dependencies. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-01s390: always use the packed stack layoutVasily Gorbik
-mpacked-stack option has been supported by both minimum gcc and clang versions for a while. With commit e2bc3e91d91e ("scripts/min-tool-version.sh: Raise minimum clang version to 13.0.0 for s390") minimum clang version now also supports a combination of flags -mpacked-stack -mbackchain -pg -mfentry and fulfills all requirements to always enable the packed stack layout. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-11-16bpf: Change value of MAX_TAIL_CALL_CNT from 32 to 33Tiezhu Yang
In the current code, the actual max tail call count is 33 which is greater than MAX_TAIL_CALL_CNT (defined as 32). The actual limit is not consistent with the meaning of MAX_TAIL_CALL_CNT and thus confusing at first glance. We can see the historical evolution from commit 04fd61ab36ec ("bpf: allow bpf programs to tail-call other bpf programs") and commit f9dabe016b63 ("bpf: Undo off-by-one in interpreter tail call count limit"). In order to avoid changing existing behavior, the actual limit is 33 now, this is reasonable. After commit 874be05f525e ("bpf, tests: Add tail call test suite"), we can see there exists failed testcase. On all archs when CONFIG_BPF_JIT_ALWAYS_ON is not set: # echo 0 > /proc/sys/net/core/bpf_jit_enable # modprobe test_bpf # dmesg | grep -w FAIL Tail call error path, max count reached jited:0 ret 34 != 33 FAIL On some archs: # echo 1 > /proc/sys/net/core/bpf_jit_enable # modprobe test_bpf # dmesg | grep -w FAIL Tail call error path, max count reached jited:1 ret 34 != 33 FAIL Although the above failed testcase has been fixed in commit 18935a72eb25 ("bpf/tests: Fix error in tail call limit tests"), it would still be good to change the value of MAX_TAIL_CALL_CNT from 32 to 33 to make the code more readable. The 32-bit x86 JIT was using a limit of 32, just fix the wrong comments and limit to 33 tail calls as the constant MAX_TAIL_CALL_CNT updated. For the mips64 JIT, use "ori" instead of "addiu" as suggested by Johan Almbladh. For the riscv JIT, use RV_REG_TCC directly to save one register move as suggested by Björn Töpel. For the other implementations, no function changes, it does not change the current limit 33, the new value of MAX_TAIL_CALL_CNT can reflect the actual max tail call count, the related tail call testcases in test_bpf module and selftests can work well for the interpreter and the JIT. Here are the test results on x86_64: # uname -m x86_64 # echo 0 > /proc/sys/net/core/bpf_jit_enable # modprobe test_bpf test_suite=test_tail_calls # dmesg | tail -1 test_bpf: test_tail_calls: Summary: 8 PASSED, 0 FAILED, [0/8 JIT'ed] # rmmod test_bpf # echo 1 > /proc/sys/net/core/bpf_jit_enable # modprobe test_bpf test_suite=test_tail_calls # dmesg | tail -1 test_bpf: test_tail_calls: Summary: 8 PASSED, 0 FAILED, [8/8 JIT'ed] # rmmod test_bpf # ./test_progs -t tailcalls #142 tailcalls:OK Summary: 1/11 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Björn Töpel <bjorn@kernel.org> Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Link: https://lore.kernel.org/bpf/1636075800-3264-1-git-send-email-yangtiezhu@loongson.cn
2021-10-26s390: introduce nospec_uses_trampoline()Sven Schnelle
and replace all of the "__is_defined(CC_USING_EXPOLINE) && !nospec_disable" occurrences. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-10-04bpf, s390: Fix potential memory leak about jit_dataTiezhu Yang
Make sure to free jit_data through kfree() in the error path. Fixes: 1c8f9b91c456 ("bpf: s390: add JIT support for multi-function programs") Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-09-16s390/bpf: Fix optimizing out zero-extensionsIlya Leoshkevich
Currently the JIT completely removes things like `reg32 += 0`, however, the BPF_ALU semantics requires the target register to be zero-extended in such cases. Fix by optimizing out only the arithmetic operation, but not the subsequent zero-extension. Reported-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend") Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-09-16s390/bpf: Fix 64-bit subtraction of the -0x80000000 constantIlya Leoshkevich
The JIT uses agfi for subtracting constants, but -(-0x80000000) cannot be represented as a 32-bit signed binary integer. Fix by using algfi in this particular case. Reported-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend") Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-09-16s390/bpf: Fix branch shortening during codegen passIlya Leoshkevich
EMIT6_PCREL() macro assumes that the previous pass generated 6 bytes of code, which is not the case if branch shortening took place. Fix by using jit->prg, like all the other EMIT6_PCREL_*() macros. Reported-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> Fixes: 4e9b4a6883dd ("s390/bpf: Use relative long branches") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-07-29bpf: Introduce BPF nospec instruction for mitigating Spectre v4Daniel Borkmann
In case of JITs, each of the JIT backends compiles the BPF nospec instruction /either/ to a machine instruction which emits a speculation barrier /or/ to /no/ machine instruction in case the underlying architecture is not affected by Speculative Store Bypass or has different mitigations in place already. This covers both x86 and (implicitly) arm64: In case of x86, we use 'lfence' instruction for mitigation. In case of arm64, we rely on the firmware mitigation as controlled via the ssbd kernel parameter. Whenever the mitigation is enabled, it works for all of the kernel code with no need to provide any additional instructions here (hence only comment in arm64 JIT). Other archs can follow as needed. The BPF nospec instruction is specifically targeting Spectre v4 since i) we don't use a serialization barrier for the Spectre v1 case, and ii) mitigation instructions for v1 and v4 might be different on some archs. The BPF nospec is required for a future commit, where the BPF verifier does annotate intermediate BPF programs with speculation barriers. Co-developed-by: Piotr Krysiuk <piotras@gmail.com> Co-developed-by: Benedict Schlueter <benedict.schlueter@rub.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Piotr Krysiuk <piotras@gmail.com> Signed-off-by: Benedict Schlueter <benedict.schlueter@rub.de> Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-07-15s390/bpf: Perform r1 range checking before accessing jit->seen_reg[r1]Colin Ian King
Currently array jit->seen_reg[r1] is being accessed before the range checking of index r1. The range changing on r1 should be performed first since it will avoid any potential out-of-range accesses on the array seen_reg[] and also it is more optimal to perform checks on r1 before fetching data from the array. Fix this by swapping the order of the checks before the array access. Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Link: https://lore.kernel.org/bpf/20210715125712.24690-1-colin.king@canonical.com
2021-03-16s390/bpf: Implement new atomic opsIlya Leoshkevich
Implement BPF_AND, BPF_OR and BPF_XOR as the existing BPF_ADD. Since the corresponding machine instructions return the old value, BPF_FETCH happens by itself, the only additional thing that is required is zero-extension. There is no single instruction that implements BPF_XCHG on s390, so use a COMPARE AND SWAP loop. BPF_CMPXCHG, on the other hand, can be implemented by a single COMPARE AND SWAP. Zero-extension is automatically inserted by the verifier. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210304233002.149096-1-iii@linux.ibm.com
2021-01-14bpf: Rename BPF_XADD and prepare to encode other atomics in .immBrendan Jackman
A subsequent patch will add additional atomic operations. These new operations will use the same opcode field as the existing XADD, with the immediate discriminating different operations. In preparation, rename the instruction mode BPF_ATOMIC and start calling the zero immediate BPF_ADD. This is possible (doesn't break existing valid BPF progs) because the immediate field is currently reserved MBZ and BPF_ADD is zero. All uses are removed from the tree but the BPF_XADD definition is kept around to avoid breaking builds for people including kernel headers. Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Björn Töpel <bjorn.topel@gmail.com> Link: https://lore.kernel.org/bpf/20210114181751.768687-5-jackmanb@google.com
2020-09-14s390/bpf: Fix multiple tail callsIlya Leoshkevich
In order to branch around tail calls (due to out-of-bounds index, exceeding tail call count or missing tail call target), JIT uses label[0] field, which contains the address of the instruction following the tail call. When there are multiple tail calls, label[0] value comes from handling of a previous tail call, which is incorrect. Fix by getting rid of label array and resolving the label address locally: for all 3 branches that jump to it, emit 0 offsets at the beginning, and then backpatch them with the correct value. Also, do not use the long jump infrastructure: the tail call sequence is known to be short, so make all 3 jumps short. Fixes: 6651ee070b31 ("s390/bpf: implement bpf_tail_call() helper") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200909232141.3099367-1-iii@linux.ibm.com
2020-08-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextLinus Torvalds
Pull networking updates from David Miller: 1) Support 6Ghz band in ath11k driver, from Rajkumar Manoharan. 2) Support UDP segmentation in code TSO code, from Eric Dumazet. 3) Allow flashing different flash images in cxgb4 driver, from Vishal Kulkarni. 4) Add drop frames counter and flow status to tc flower offloading, from Po Liu. 5) Support n-tuple filters in cxgb4, from Vishal Kulkarni. 6) Various new indirect call avoidance, from Eric Dumazet and Brian Vazquez. 7) Fix BPF verifier failures on 32-bit pointer arithmetic, from Yonghong Song. 8) Support querying and setting hardware address of a port function via devlink, use this in mlx5, from Parav Pandit. 9) Support hw ipsec offload on bonding slaves, from Jarod Wilson. 10) Switch qca8k driver over to phylink, from Jonathan McDowell. 11) In bpftool, show list of processes holding BPF FD references to maps, programs, links, and btf objects. From Andrii Nakryiko. 12) Several conversions over to generic power management, from Vaibhav Gupta. 13) Add support for SO_KEEPALIVE et al. to bpf_setsockopt(), from Dmitry Yakunin. 14) Various https url conversions, from Alexander A. Klimov. 15) Timestamping and PHC support for mscc PHY driver, from Antoine Tenart. 16) Support bpf iterating over tcp and udp sockets, from Yonghong Song. 17) Support 5GBASE-T i40e NICs, from Aleksandr Loktionov. 18) Add kTLS RX HW offload support to mlx5e, from Tariq Toukan. 19) Fix the ->ndo_start_xmit() return type to be netdev_tx_t in several drivers. From Luc Van Oostenryck. 20) XDP support for xen-netfront, from Denis Kirjanov. 21) Support receive buffer autotuning in MPTCP, from Florian Westphal. 22) Support EF100 chip in sfc driver, from Edward Cree. 23) Add XDP support to mvpp2 driver, from Matteo Croce. 24) Support MPTCP in sock_diag, from Paolo Abeni. 25) Commonize UDP tunnel offloading code by creating udp_tunnel_nic infrastructure, from Jakub Kicinski. 26) Several pci_ --> dma_ API conversions, from Christophe JAILLET. 27) Add FLOW_ACTION_POLICE support to mlxsw, from Ido Schimmel. 28) Add SK_LOOKUP bpf program type, from Jakub Sitnicki. 29) Refactor a lot of networking socket option handling code in order to avoid set_fs() calls, from Christoph Hellwig. 30) Add rfc4884 support to icmp code, from Willem de Bruijn. 31) Support TBF offload in dpaa2-eth driver, from Ioana Ciornei. 32) Support XDP_REDIRECT in qede driver, from Alexander Lobakin. 33) Support PCI relaxed ordering in mlx5 driver, from Aya Levin. 34) Support TCP syncookies in MPTCP, from Flowian Westphal. 35) Fix several tricky cases of PMTU handling wrt. briding, from Stefano Brivio. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2056 commits) net: thunderx: initialize VF's mailbox mutex before first usage usb: hso: remove bogus check for EINPROGRESS usb: hso: no complaint about kmalloc failure hso: fix bailout in error case of probe ip_tunnel_core: Fix build for archs without _HAVE_ARCH_IPV6_CSUM selftests/net: relax cpu affinity requirement in msg_zerocopy test mptcp: be careful on subflow creation selftests: rtnetlink: make kci_test_encap() return sub-test result selftests: rtnetlink: correct the final return value for the test net: dsa: sja1105: use detected device id instead of DT one on mismatch tipc: set ub->ifindex for local ipv6 address ipv6: add ipv6_dev_find() net: openvswitch: silence suspicious RCU usage warning Revert "vxlan: fix tos value before xmit" ptp: only allow phase values lower than 1 period farsync: switch from 'pci_' to 'dma_' API wan: wanxl: switch from 'pci_' to 'dma_' API hv_netvsc: do not use VF device if link is down dpaa2-eth: Fix passing zero to 'PTR_ERR' warning net: macb: Properly handle phylink on at91sam9x ...
2020-07-21s390/bpf: Use bpf_skip() in bpf_jit_prologue()Ilya Leoshkevich
Now that we have bpf_skip() for emitting nops, use it in bpf_jit_prologue() in order to reduce code duplication. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200717165326.6786-6-iii@linux.ibm.com
2020-07-21s390/bpf: Tolerate not converging code shrinkingIlya Leoshkevich
"BPF_MAXINSNS: Maximum possible literals" unnecessarily falls back to the interpreter because of failing sanity check in bpf_set_addr. The problem is that there are a lot of branches that can be shrunk, and doing so opens up the possibility to shrink even more. This process does not converge after 3 passes, causing code offsets to change during the codegen pass, which must never happen. Fix by inserting nops during codegen pass in order to preserve code offets. Fixes: 4e9b4a6883dd ("s390/bpf: Use relative long branches") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200717165326.6786-5-iii@linux.ibm.com
2020-07-21s390/bpf: Use brcl for jumping to exit_ip if necessaryIlya Leoshkevich
"BPF_MAXINSNS: Maximum possible literals" test causes panic with bpf_jit_harden = 2. The reason is that BPF_JMP | BPF_EXIT is always emitted as brc, however, after removal of JITed image size limitations, brcl might be required. Fix by using brcl when necessary. Fixes: 4e9b4a6883dd ("s390/bpf: Use relative long branches") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200717165326.6786-4-iii@linux.ibm.com
2020-07-21s390/bpf: Fix sign extension in branch_kuIlya Leoshkevich
Both signed and unsigned variants of BPF_JMP | BPF_K require sign-extending the immediate. JIT emits cgfi for the signed case, which is correct, and clgfi for the unsigned case, which is not correct: clgfi zero-extends the immediate. s390 does not provide an instruction that does sign-extension and unsigned comparison at the same time. Therefore, fix by first loading the sign-extended immediate into work register REG_1 and proceeding as if it's BPF_X. Fixes: 4e9b4a6883dd ("s390/bpf: Use relative long branches") Reported-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Seth Forshee <seth.forshee@canonical.com> Link: https://lore.kernel.org/bpf/20200717165326.6786-3-iii@linux.ibm.com
2020-07-20s390/bpf: implement BPF_PROBE_MEMIlya Leoshkevich
This is a s390 port of x86 commit 3dec541b2e63 ("bpf: Add support for BTF pointers to x86 JIT"). Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-06-02s390/bpf: Use bcr 0,%0 as tail call nop fillerIlya Leoshkevich
Currently used 0x0000 filler confuses bfd disassembler, making bpftool prog dump xlated output nearly useless. Fix by using a real instruction. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200602174555.2501389-1-iii@linux.ibm.com
2020-06-02s390/bpf: Maintain 8-byte stack alignmentIlya Leoshkevich
Certain kernel functions (e.g. get_vtimer/set_vtimer) cause kernel panic when the stack is not 8-byte aligned. Currently JITed BPF programs may trigger this by allocating stack frames with non-rounded sizes and then being interrupted. Fix by using rounded fp->aux->stack_depth. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200602174339.2501066-1-iii@linux.ibm.com
2019-11-18s390/bpf: Remove JITed image size limitationsIlya Leoshkevich
Now that jump and long displacement ranges are no longer a problem, remove the limit on JITed image size. In practice it's still limited by 2G, but with verifier allowing "only" 1M instructions, it's not an issue. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191118180340.68373-7-iii@linux.ibm.com
2019-11-18s390/bpf: Use lg(f)rl when long displacement cannot be usedIlya Leoshkevich
If literal pool grows past 524287 mark, it's no longer possible to use long displacement to reference literal pool entries. In JIT setting maintaining multiple literal pool registers is next to impossible, since we operate on one instruction at a time. Therefore, fall back to loading literal pool entry using PC-relative addressing, and then using a register-register form of the following machine instruction. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191118180340.68373-6-iii@linux.ibm.com
2019-11-18s390/bpf: Use lgrl instead of lg where possibleIlya Leoshkevich
lg and lgrl have the same performance characteristics, but the former requires a base register and is subject to long displacement range limits, while the latter does not. Therefore, lgrl is totally superior to lg and should be used instead whenever possible. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191118180340.68373-5-iii@linux.ibm.com
2019-11-18s390/bpf: Load literal pool register using larlIlya Leoshkevich
Currently literal pool register is loaded using basr, which makes it point not to the beginning of the literal pool, but rather to the next instruction. In case JITed code is larger than 512k, this renders literal pool register absolutely useless due to long displacement range restrictions. The solution is to use larl to make literal pool register point to the very beginning of the literal pool. This makes it always possible to address 512k worth of literal pool entries using long displacement. However, for short programs, in which the entire literal pool is covered by basr-generated base, it is still beneficial to use basr, since it is 4 bytes shorter than larl. Detect situations when basr-generated base does not cover the entire literal pool, and in such cases use larl instead. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191118180340.68373-4-iii@linux.ibm.com
2019-11-18s390/bpf: Align literal pool entriesIlya Leoshkevich
When literal pool size exceeds 512k, it's no longer possible to reference all the entries in it using a single base register and long displacement. Therefore, PC-relative lgfrl and lgrl instructions need to be used. Unfortunately, they require their arguments to be aligned to 4- and 8-byte boundaries respectively. This generates certain overhead due to necessary padding bytes. Grouping 4- and 8-byte entries together reduces the maximum overhead to 6 bytes (2 for aligning 4-byte entries and 4 for aligning 8-byte entries). While in theory it is possible to detect whether or not alignment is needed by comparing the literal pool size with 512k, in practice this leads to having two ways of emitting constants, making the code more complicated. Prefer code simplicity over trivial size saving, and always group and align literal pool entries. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191118180340.68373-3-iii@linux.ibm.com
2019-11-18s390/bpf: Use relative long branchesIlya Leoshkevich
Currently maximum JITed code size is limited to 64k, because JIT can emit only relative short branches, whose range is limited by 64k in both directions. Teach JIT to use relative long branches. There are no compare+branch relative long instructions, so using relative long branches consumes more space due to having to having to emit an explicit comparison instruction. Therefore do this only when relative short branch is not enough. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191118180340.68373-2-iii@linux.ibm.com
2019-11-15s390/bpf: Make sure JIT passes do not increase code sizeIlya Leoshkevich
The upcoming s390 branch length extension patches rely on "passes do not increase code size" property in order to consistently choose between short and long branches. Currently this property does not hold between the first and the second passes for register save/restore sequences, as well as various code fragments that depend on SEEN_* flags. Generate the code during the first pass conservatively: assume register save/restore sequences have the maximum possible length, and that all SEEN_* flags are set. Also refuse to JIT if this happens anyway (e.g. due to a bug), as this might lead to verifier bypass once long branches are introduced. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191114151820.53222-1-iii@linux.ibm.com
2019-11-07s390/bpf: Remove unused SEEN_RET0, SEEN_REG_AX and ret0_ipIlya Leoshkevich
We don't need them since commit e1cf4befa297 ("bpf, s390x: remove ld_abs/ld_ind") and commit a3212b8f15d8 ("bpf, s390x: remove obsolete exception handling from div/mod"). Also, use BIT(n) instead of 1 << n, because checkpatch says so. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191107114033.90505-1-iii@linux.ibm.com
2019-11-07s390/bpf: Wrap JIT macro parameter usages in parenthesesIlya Leoshkevich
This change does not alter JIT behavior; it only makes it possible to safely invoke JIT macros with complex arguments in the future. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191107113211.90105-1-iii@linux.ibm.com
2019-11-07s390/bpf: Use kvcalloc for addrs arrayIlya Leoshkevich
A BPF program may consist of 1m instructions, which means JIT instruction-address mapping can be as large as 4m. s390 has FORCE_MAX_ZONEORDER=9 (for memory hotplug reasons), which means maximum kmalloc size is 1m. This makes it impossible to JIT programs with more than 256k instructions. Fix by using kvcalloc, which falls back to vmalloc for larger allocations. An alternative would be to use a radix tree, but that is not supported by bpf_prog_fill_jited_linfo. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191107141838.92202-1-iii@linux.ibm.com
2019-09-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Daniel Borkmann says: ==================== The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Add the ability to use unaligned chunks in the AF_XDP umem. By relaxing where the chunks can be placed, it allows to use an arbitrary buffer size and place whenever there is a free address in the umem. Helps more seamless DPDK AF_XDP driver integration. Support for i40e, ixgbe and mlx5e, from Kevin and Maxim. 2) Addition of a wakeup flag for AF_XDP tx and fill rings so the application can wake up the kernel for rx/tx processing which avoids busy-spinning of the latter, useful when app and driver is located on the same core. Support for i40e, ixgbe and mlx5e, from Magnus and Maxim. 3) bpftool fixes for printf()-like functions so compiler can actually enforce checks, bpftool build system improvements for custom output directories, and addition of 'bpftool map freeze' command, from Quentin. 4) Support attaching/detaching XDP programs from 'bpftool net' command, from Daniel. 5) Automatic xskmap cleanup when AF_XDP socket is released, and several barrier/{read,write}_once fixes in AF_XDP code, from Björn. 6) Relicense of bpf_helpers.h/bpf_endian.h for future libbpf inclusion as well as libbpf versioning improvements, from Andrii. 7) Several new BPF kselftests for verifier precision tracking, from Alexei. 8) Several BPF kselftest fixes wrt endianess to run on s390x, from Ilya. 9) And more BPF kselftest improvements all over the place, from Stanislav. 10) Add simple BPF map op cache for nfp driver to batch dumps, from Jakub. 11) AF_XDP socket umem mapping improvements for 32bit archs, from Ivan. 12) Add BPF-to-BPF call and BTF line info support for s390x JIT, from Yauheni. 13) Small optimization in arm64 JIT to spare 1 insns for BPF_MOD, from Jerin. 14) Fix an error check in bpf_tcp_gen_syncookie() helper, from Petar. 15) Various minor fixes and cleanups, from Nathan, Masahiro, Masanari, Peter, Wei, Yue. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-03bpf: s390: add JIT support for bpf line infoYauheni Kaliuta
This adds support for generating bpf line info for JITed programs like commit 6f20c71d8505 ("bpf: powerpc64: add JIT support for bpf line info") does for powerpc, but it should pass the array starting from 1. This fixes test_btf. Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-31bpf: s390: add JIT support for multi-function programsYauheni Kaliuta
This adds support for bpf-to-bpf function calls in the s390 JIT compiler. The JIT compiler converts the bpf call instructions to native branch instructions. After a round of the usual passes, the start addresses of the JITed images for the callee functions are known. Finally, to fixup the branch target addresses, we need to perform an extra pass. Because of the address range in which JITed images are allocated on s390, the offsets of the start addresses of these images from __bpf_call_base are as large as 64 bits. So, for a function call, the imm field of the instruction cannot be used to determine the callee's address. Use bpf_jit_get_func_addr() helper instead. The patch borrows a lot from: commit 8c11ea5ce13d ("bpf, arm64: fix getting subprog addr from aux for calls") commit e2c95a61656d ("bpf, ppc64: generalize fetching subprog into bpf_jit_get_func_addr") commit 8484ce8306f9 ("bpf: powerpc64: add JIT support for multi-function programs") (including the commit message). test_verifier (5.3-rc6 with CONFIG_BPF_JIT_ALWAYS_ON=y): without patch: Summary: 1501 PASSED, 0 SKIPPED, 47 FAILED with patch: Summary: 1540 PASSED, 0 SKIPPED, 8 FAILED Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-13s390/bpf: use 32-bit index for tail callsIlya Leoshkevich
"p runtime/jit: pass > 32bit index to tail_call" fails when bpf_jit_enable=1, because the tail call is not executed. This in turn is because the generated code assumes index is 64-bit, while it must be 32-bit, and as a result prog array bounds check fails, while it should pass. Even if bounds check would have passed, the code that follows uses 64-bit index to compute prog array offset. Fix by using clrj instead of clgrj for comparing index with array size, and also by using llgfr for truncating index to 32 bits before using it to compute prog array offset. Fixes: 6651ee070b31 ("s390/bpf: implement bpf_tail_call() helper") Reported-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-12s390/bpf: fix lcgr instruction encodingIlya Leoshkevich
"masking, test in bounds 3" fails on s390, because BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0) ignores the top 32 bits of BPF_REG_2. The reason is that JIT emits lcgfr instead of lcgr. The associated comment indicates that the code was intended to emit lcgr in the first place, it's just that the wrong opcode was used. Fix by using the correct opcode. Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-24s390: bpf: eliminate zero extension code-genJiong Wang
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-11s390: Convert IS_ENABLED uses to __is_definedJoe Perches
IS_ENABLED should be reserved for CONFIG_<FOO> uses so convert the uses of IS_ENABLED with a #define to __is_defined. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-02-21s390/net: convert pnetids to asciiHans Wippel
Pnetids are retrieved from the underlying hardware as EBCDIC. This patch converts pnetids to ASCII. Signed-off-by: Hans Wippel <hwippel@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-07s390/net: move pnet constantsUrsula Braun
There is no need to define these PNETID related constants in the pnet.h file, since they are just used locally within pnet.c. Just code cleanup, no functional change. Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-04s390: bpf: fix JMP32 code-genHeiko Carstens
Commit 626a5f66da0d19 ("s390: bpf: implement jitting of JMP32") added JMP32 code-gen support for s390. However it triggers the warning below due to some unusual gotos in the original s390 bpf jit code. Add a couple of additional "is_jmp32" initializations to fix this. Also fix the wrong opcode for the "llilf" instruction that was introduced with the same commit. arch/s390/net/bpf_jit_comp.c: In function 'bpf_jit_insn': arch/s390/net/bpf_jit_comp.c:248:55: warning: 'is_jmp32' may be used uninitialized in this function [-Wmaybe-uninitialized] _EMIT6(op1 | reg(b1, b2) << 16 | (rel & 0xffff), op2 | mask); \ ^ arch/s390/net/bpf_jit_comp.c:1211:8: note: 'is_jmp32' was declared here bool is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32; Fixes: 626a5f66da0d19 ("s390: bpf: implement jitting of JMP32") Cc: Jiong Wang <jiong.wang@netronome.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Jiong Wang <jiong.wang@netronome.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-26s390: bpf: implement jitting of JMP32Jiong Wang
This patch implements code-gen for new JMP32 instructions on s390. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-07s390: bpf: implement jitting of BPF_ALU | BPF_ARSH | BPF_*Jiong Wang
This patch implements code-gen for BPF_ALU | BPF_ARSH | BPF_*. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-08-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: "Since Martin is on vacation you get the s390 pull request from me: - Host large page support for KVM guests. As the patches have large impact on arch/s390/mm/ this series goes out via both the KVM and the s390 tree. - Add an option for no compression to the "Kernel compression mode" menu, this will come in handy with the rework of the early boot code. - A large rework of the early boot code that will make life easier for KASAN and KASLR. With the rework the bootable uncompressed image is not generated anymore, only the bzImage is available. For debuggung purposes the new "no compression" option is used. - Re-enable the gcc plugins as the issue with the latent entropy plugin is solved with the early boot code rework. - More spectre relates changes: + Detect the etoken facility and remove expolines automatically. + Add expolines to a few more indirect branches. - A rewrite of the common I/O layer trace points to make them consumable by 'perf stat'. - Add support for format-3 PCI function measurement blocks. - Changes for the zcrypt driver: + Add attributes to indicate the load of cards and queues. + Restructure some code for the upcoming AP device support in KVM. - Build flags improvements in various Makefiles. - A few fixes for the kdump support. - A couple of patches for gcc 8 compile warning cleanup. - Cleanup s390 specific proc handlers. - Add s390 support to the restartable sequence self tests. - Some PTR_RET vs PTR_ERR_OR_ZERO cleanup. - Lots of bug fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (107 commits) s390/dasd: fix hanging offline processing due to canceled worker s390/dasd: fix panic for failed online processing s390/mm: fix addressing exception after suspend/resume rseq/selftests: add s390 support s390: fix br_r1_trampoline for machines without exrl s390/lib: use expoline for all bcr instructions s390/numa: move initial setup of node_to_cpumask_map s390/kdump: Fix elfcorehdr size calculation s390/cpum_sf: save TOD clock base in SDBs for time conversion KVM: s390: Add huge page enablement control s390/mm: Add huge page gmap linking support s390/mm: hugetlb pages within a gmap can not be freed KVM: s390: Add skey emulation fault handling s390/mm: Add huge pmd storage key handling s390/mm: Clear skeys for newly mapped huge guest pmds s390/mm: Clear huge page storage keys on enable_skey s390/mm: Add huge page dirty sync support s390/mm: Add gmap pmd invalidation and clearing s390/mm: Add gmap pmd notification bit setting s390/mm: Add gmap pmd linking ...
2018-08-07s390: fix br_r1_trampoline for machines without exrlMartin Schwidefsky
For machines without the exrl instruction the BFP jit generates code that uses an "br %r1" instruction located in the lowcore page. Unfortunately there is a cut & paste error that puts an additional "larl %r1,.+14" instruction in the code that clobbers the branch target address in %r1. Remove the larl instruction. Cc: <stable@vger.kernel.org> # v4.17+ Fixes: de5cb6eb51 ("s390: use expoline thunks in the BPF JIT") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>