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* bpf, riscv: Support riscv jit to provide bpf_line_infoPu Lehui2022-06-032-1/+8
| | | | | | | | | | | | | | Add support for riscv jit to provide bpf_line_info. We need to consider the prologue offset in ctx->offset, but unlike x86 and arm64, ctx->offset of riscv does not provide an extra slot for the prologue, so here we just calculate the len of prologue and add it to ctx->offset at the end. Both RV64 and RV32 have been tested. Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220530092815.1112406-3-pulehui@huawei.com
* riscv, bpf: Implement more atomic operations for RV64Pu Lehui2022-04-112-24/+153
| | | | | | | | | | | | | | | | | | | | | | | | This patch implement more BPF atomic operations for RV64. The newly added operations are shown below: atomic[64]_[fetch_]add atomic[64]_[fetch_]and atomic[64]_[fetch_]or atomic[64]_xchg atomic[64]_cmpxchg Since riscv specification does not provide AMO instruction for CAS operation, we use lr/sc instruction for cmpxchg operation, and AMO instructions for the rest ops. Tests "test_bpf.ko" and "test_progs -t atomic" have passed, as well as "test_verifier" with no new failure cases. Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Acked-by: Björn Töpel <bjorn@kernel.org> Link: https://lore.kernel.org/bpf/20220410101246.232875-1-pulehui@huawei.com
* riscv: bpf: Fix eBPF's exception tablesJisheng Zhang2022-01-191-1/+1
| | | | | | | | | eBPF's exception tables needs to be modified to relative synchronously. Suggested-by: Tong Tiangen <tongtiangen@huawei.com> Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Fixes: 1f77ed9422cb ("riscv: switch to relative extable and other improvements") Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
* Merge tag 'riscv-for-linus-5.17-mw0' of ↵Linus Torvalds2022-01-191-5/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: - Support for the DA9063 as used on the HiFive Unmatched. - Support for relative extables, which puts us in line with other architectures and save some space in vmlinux. - A handful of kexec fixes/improvements, including the ability to run crash kernels from PCI-addressable memory on the HiFive Unmatched. - Support for the SBI SRST extension, which allows systems that do not have an explicit driver in Linux to reboot. - A handful of fixes and cleanups, including to the defconfigs and device trees. * tag 'riscv-for-linus-5.17-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (52 commits) RISC-V: Use SBI SRST extension when available riscv: mm: fix wrong phys_ram_base value for RV64 RISC-V: Use common riscv_cpuid_to_hartid_mask() for both SMP=y and SMP=n riscv: head: remove useless __PAGE_ALIGNED_BSS and .balign riscv: errata: alternative: mark vendor_patch_func __initdata riscv: head: make secondary_start_common() static riscv: remove cpu_stop() riscv: try to allocate crashkern region from 32bit addressible memory riscv: use hart id instead of cpu id on machine_kexec riscv: Don't use va_pa_offset on kdump riscv: dts: sifive: fu540-c000: Fix PLIC node riscv: dts: sifive: fu540-c000: Drop bogus soc node compatible values riscv: dts: sifive: Group tuples in register properties riscv: dts: sifive: Group tuples in interrupt properties riscv: dts: microchip: mpfs: Group tuples in interrupt properties riscv: dts: microchip: mpfs: Fix clock controller node riscv: dts: microchip: mpfs: Fix reference clock node riscv: dts: microchip: mpfs: Fix PLIC node riscv: dts: microchip: mpfs: Drop empty chosen node riscv: dts: canaan: Group tuples in interrupt properties ...
| * riscv: extable: add `type` and `data` fieldsJisheng Zhang2022-01-061-2/+3
| | | | | | | | | | | | | | | | This is a riscv port of commit d6e2cc564775 ("arm64: extable: add `type` and `data` fields"). Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * riscv: extable: make fixup_exception() return boolJisheng Zhang2022-01-061-3/+3
| | | | | | | | | | | | | | | | | | The return values of fixup_exception() and riscv_bpf_fixup_exception() represent a boolean condition rather than an error code, so it's better to return `bool` rather than `int`. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * riscv: bpf: move rv_bpf_fixup_exception signature to extable.hJisheng Zhang2022-01-061-2/+0
| | | | | | | | | | | | | | | | This is to group riscv related extable related functions signature into one file. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
* | bpf: Change value of MAX_TAIL_CALL_CNT from 32 to 33Tiezhu Yang2021-11-162-8/+5
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* riscv, bpf: Fix RV32 broken build, and silence RV64 warningBjörn Töpel2021-11-051-0/+2
| | | | | | | | | | | | | | | | | Commit 252c765bd764 ("riscv, bpf: Add BPF exception tables") only addressed RV64, and broke the RV32 build [1]. Fix by gating the exception tables code with CONFIG_ARCH_RV64I. Further, silence a "-Wmissing-prototypes" warning [2] in the RV64 BPF JIT. [1] https://lore.kernel.org/llvm/202111020610.9oy9Rr0G-lkp@intel.com/ [2] https://lore.kernel.org/llvm/202110290334.2zdMyRq4-lkp@intel.com/ Fixes: 252c765bd764 ("riscv, bpf: Add BPF exception tables") Signed-off-by: Björn Töpel <bjorn@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Tong Tiangen <tongtiangen@huawei.com> Link: https://lore.kernel.org/bpf/20211103115453.397209-1-bjorn@kernel.org
* Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski2021-11-023-43/+164
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexei Starovoitov says: ==================== pull-request: bpf-next 2021-11-01 We've added 181 non-merge commits during the last 28 day(s) which contain a total of 280 files changed, 11791 insertions(+), 5879 deletions(-). The main changes are: 1) Fix bpf verifier propagation of 64-bit bounds, from Alexei. 2) Parallelize bpf test_progs, from Yucong and Andrii. 3) Deprecate various libbpf apis including af_xdp, from Andrii, Hengqi, Magnus. 4) Improve bpf selftests on s390, from Ilya. 5) bloomfilter bpf map type, from Joanne. 6) Big improvements to JIT tests especially on Mips, from Johan. 7) Support kernel module function calls from bpf, from Kumar. 8) Support typeless and weak ksym in light skeleton, from Kumar. 9) Disallow unprivileged bpf by default, from Pawan. 10) BTF_KIND_DECL_TAG support, from Yonghong. 11) Various bpftool cleanups, from Quentin. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (181 commits) libbpf: Deprecate AF_XDP support kbuild: Unify options for BTF generation for vmlinux and modules selftests/bpf: Add a testcase for 64-bit bounds propagation issue. bpf: Fix propagation of signed bounds from 64-bit min/max into 32-bit. bpf: Fix propagation of bounds from 64-bit min/max into 32-bit and var_off. selftests/bpf: Fix also no-alu32 strobemeta selftest bpf: Add missing map_delete_elem method to bloom filter map selftests/bpf: Add bloom map success test for userspace calls bpf: Add alignment padding for "map_extra" + consolidate holes bpf: Bloom filter map naming fixups selftests/bpf: Add test cases for struct_ops prog bpf: Add dummy BPF STRUCT_OPS for test purpose bpf: Factor out helpers for ctx access checking bpf: Factor out a helper to prepare trampoline for struct_ops prog selftests, bpf: Fix broken riscv build riscv, libbpf: Add RISC-V (RV64) support to bpf_tracing.h tools, build: Add RISC-V to HOSTARCH parsing riscv, bpf: Increase the maximum number of iterations selftests, bpf: Add one test for sockmap with strparser selftests, bpf: Fix test_txmsg_ingress_parser error ... ==================== Link: https://lore.kernel.org/r/20211102013123.9005-1-alexei.starovoitov@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * riscv, bpf: Increase the maximum number of iterationsBjörn Töpel2021-11-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Now that BPF programs can be up to 1M instructions, it is not uncommon that a program requires more than the current 16 iterations to converge. Bump it to 32, which is enough for selftests/bpf, and test_bpf.ko. Signed-off-by: Björn Töpel <bjorn@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211028161057.520552-2-bjorn@kernel.org
| * riscv, bpf: Add BPF exception tablesTong Tiangen2021-10-283-42/+163
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a tracing BPF program attempts to read memory without using the bpf_probe_read() helper, the verifier marks the load instruction with the BPF_PROBE_MEM flag. Since the riscv JIT does not currently recognize this flag it falls back to the interpreter. Add support for BPF_PROBE_MEM, by appending an exception table to the BPF program. If the load instruction causes a data abort, the fixup infrastructure finds the exception table and fixes up the fault, by clearing the destination register and jumping over the faulting instruction. A more generic solution would add a "handler" field to the table entry, like on x86 and s390. The same issue in ARM64 is fixed in 800834285361 ("bpf, arm64: Add BPF exception tables"). Signed-off-by: Tong Tiangen <tongtiangen@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Pu Lehui <pulehui@huawei.com> Tested-by: Björn Töpel <bjorn@kernel.org> Acked-by: Björn Töpel <bjorn@kernel.org> Link: https://lore.kernel.org/bpf/20211027111822.3801679-1-tongtiangen@huawei.com
* | riscv, bpf: Fix potential NULL dereferenceBjörn Töpel2021-10-281-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The bpf_jit_binary_free() function requires a non-NULL argument. When the RISC-V BPF JIT fails to converge in NR_JIT_ITERATIONS steps, jit_data->header will be NULL, which triggers a NULL dereference. Avoid this by checking the argument, prior calling the function. Fixes: ca6cb5447cec ("riscv, bpf: Factor common RISC-V JIT code") Signed-off-by: Björn Töpel <bjorn@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20211028125115.514587-1-bjorn@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | bpf: Define bpf_jit_alloc_exec_limit for riscv JITLorenz Bauer2021-10-231-0/+5
|/ | | | | | | | | | Expose the maximum amount of useable memory from the riscv JIT. Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Luke Nelson <luke.r.nels@gmail.com> Acked-by: Björn Töpel <bjorn@kernel.org> Link: https://lore.kernel.org/bpf/20211014142554.53120-2-lmb@cloudflare.com
* bpf: Introduce BPF nospec instruction for mitigating Spectre v4Daniel Borkmann2021-07-292-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* riscv: bpf: Avoid breaking W^XJisheng Zhang2021-04-261-1/+2
| | | | | | | | | We allocate Non-executable pages, then call bpf_jit_binary_lock_ro() to enable executable permission after mapping them read-only. This is to prepare for STRICT_MODULE_RWX in following patch. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* riscv: bpf: Move bpf_jit_alloc_exec() and bpf_jit_free_exec() to coreJisheng Zhang2021-04-262-13/+13
| | | | | | | | | | | We will drop the executable permissions of the code pages from the mapping at allocation time soon. Move bpf_jit_alloc_exec() and bpf_jit_free_exec() to bpf_jit_core.c so that they can be shared by both RV64I and RV32I. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Acked-by: Luke Nelson <luke.r.nels@gmail.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* bpf: Rename BPF_XADD and prepare to encode other atomics in .immBrendan Jackman2021-01-152-8/+28
| | | | | | | | | | | | | | | | | | | | | 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
* treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva2020-08-241-2/+2
| | | | | | | | | | Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
* bpf, riscv: Use compressed instructions in the rv64 JITLuke Nelson2020-07-211-134/+147
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch uses the RVC support and encodings from bpf_jit.h to optimize the rv64 jit. The optimizations work by replacing emit(rv_X(...)) with a call to a helper function emit_X, which will emit a compressed version of the instruction when possible, and when RVC is enabled. The JIT continues to pass all tests in lib/test_bpf.c, and introduces no new failures to test_verifier; both with and without RVC being enabled. Most changes are straightforward replacements of emit(rv_X(...), ctx) with emit_X(..., ctx), with the following exceptions bearing mention; * Change emit_imm to sign-extend the value in "lower", since the checks for RVC (and the instructions themselves) treat the value as signed. Otherwise, small negative immediates will not be recognized as encodable using an RVC instruction. For example, without this change, emit_imm(rd, -1, ctx) would cause lower to become 4095, which is not a 6b int even though a "c.li rd, -1" instruction suffices. * For {BPF_MOV,BPF_ADD} BPF_X, drop using addiw,addw in the 32-bit cases since the values are zero-extended into the upper 32 bits in the following instructions anyways, and the addition commutes with zero-extension. (BPF_SUB BPF_X must still use subw since subtraction does not commute with zero-extension.) This patch avoids optimizing branches and jumps to use RVC instructions since surrounding code often makes assumptions about the sizes of emitted instructions. Optimizing these will require changing these functions (e.g., emit_branch) to dynamically compute jump offsets. The following are examples of the JITed code for the verifier selftest "direct packet read test#3 for CGROUP_SKB OK", without and with RVC enabled, respectively. The former uses 178 bytes, and the latter uses 112, for a ~37% reduction in code size for this example. Without RVC: 0: 02000813 addi a6,zero,32 4: fd010113 addi sp,sp,-48 8: 02813423 sd s0,40(sp) c: 02913023 sd s1,32(sp) 10: 01213c23 sd s2,24(sp) 14: 01313823 sd s3,16(sp) 18: 01413423 sd s4,8(sp) 1c: 03010413 addi s0,sp,48 20: 03056683 lwu a3,48(a0) 24: 02069693 slli a3,a3,0x20 28: 0206d693 srli a3,a3,0x20 2c: 03456703 lwu a4,52(a0) 30: 02071713 slli a4,a4,0x20 34: 02075713 srli a4,a4,0x20 38: 03856483 lwu s1,56(a0) 3c: 02049493 slli s1,s1,0x20 40: 0204d493 srli s1,s1,0x20 44: 03c56903 lwu s2,60(a0) 48: 02091913 slli s2,s2,0x20 4c: 02095913 srli s2,s2,0x20 50: 04056983 lwu s3,64(a0) 54: 02099993 slli s3,s3,0x20 58: 0209d993 srli s3,s3,0x20 5c: 09056a03 lwu s4,144(a0) 60: 020a1a13 slli s4,s4,0x20 64: 020a5a13 srli s4,s4,0x20 68: 00900313 addi t1,zero,9 6c: 006a7463 bgeu s4,t1,0x74 70: 00000a13 addi s4,zero,0 74: 02d52823 sw a3,48(a0) 78: 02e52a23 sw a4,52(a0) 7c: 02952c23 sw s1,56(a0) 80: 03252e23 sw s2,60(a0) 84: 05352023 sw s3,64(a0) 88: 00000793 addi a5,zero,0 8c: 02813403 ld s0,40(sp) 90: 02013483 ld s1,32(sp) 94: 01813903 ld s2,24(sp) 98: 01013983 ld s3,16(sp) 9c: 00813a03 ld s4,8(sp) a0: 03010113 addi sp,sp,48 a4: 00078513 addi a0,a5,0 a8: 00008067 jalr zero,0(ra) With RVC: 0: 02000813 addi a6,zero,32 4: 7179 c.addi16sp sp,-48 6: f422 c.sdsp s0,40(sp) 8: f026 c.sdsp s1,32(sp) a: ec4a c.sdsp s2,24(sp) c: e84e c.sdsp s3,16(sp) e: e452 c.sdsp s4,8(sp) 10: 1800 c.addi4spn s0,sp,48 12: 03056683 lwu a3,48(a0) 16: 1682 c.slli a3,0x20 18: 9281 c.srli a3,0x20 1a: 03456703 lwu a4,52(a0) 1e: 1702 c.slli a4,0x20 20: 9301 c.srli a4,0x20 22: 03856483 lwu s1,56(a0) 26: 1482 c.slli s1,0x20 28: 9081 c.srli s1,0x20 2a: 03c56903 lwu s2,60(a0) 2e: 1902 c.slli s2,0x20 30: 02095913 srli s2,s2,0x20 34: 04056983 lwu s3,64(a0) 38: 1982 c.slli s3,0x20 3a: 0209d993 srli s3,s3,0x20 3e: 09056a03 lwu s4,144(a0) 42: 1a02 c.slli s4,0x20 44: 020a5a13 srli s4,s4,0x20 48: 4325 c.li t1,9 4a: 006a7363 bgeu s4,t1,0x50 4e: 4a01 c.li s4,0 50: d914 c.sw a3,48(a0) 52: d958 c.sw a4,52(a0) 54: dd04 c.sw s1,56(a0) 56: 03252e23 sw s2,60(a0) 5a: 05352023 sw s3,64(a0) 5e: 4781 c.li a5,0 60: 7422 c.ldsp s0,40(sp) 62: 7482 c.ldsp s1,32(sp) 64: 6962 c.ldsp s2,24(sp) 66: 69c2 c.ldsp s3,16(sp) 68: 6a22 c.ldsp s4,8(sp) 6a: 6145 c.addi16sp sp,48 6c: 853e c.mv a0,a5 6e: 8082 c.jr ra Signed-off-by: Luke Nelson <luke.r.nels@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Björn Töpel <bjorn.topel@gmail.com> Link: https://lore.kernel.org/bpf/20200721025241.8077-4-luke.r.nels@gmail.com
* bpf, riscv: Add encodings for compressed instructionsLuke Nelson2020-07-211-0/+452
| | | | | | | | | | | | | | | | | | | | This patch adds functions for encoding and emitting compressed riscv (RVC) instructions to the BPF JIT. Some regular riscv instructions can be compressed into an RVC instruction if the instruction fields meet some requirements. For example, "add rd, rs1, rs2" can be compressed into "c.add rd, rs2" when rd == rs1. To make using RVC encodings simpler, this patch also adds helper functions that selectively emit either a regular instruction or a compressed instruction if possible. For example, emit_add will produce a "c.add" if possible and regular "add" otherwise. Signed-off-by: Luke Nelson <luke.r.nels@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200721025241.8077-3-luke.r.nels@gmail.com
* bpf, riscv: Modify JIT ctx to support compressed instructionsLuke Nelson2020-07-214-19/+44
| | | | | | | | | | | | | | | | | | | | | This patch makes the necessary changes to struct rv_jit_context and to bpf_int_jit_compile to support compressed riscv (RVC) instructions in the BPF JIT. It changes the JIT image to be u16 instead of u32, since RVC instructions are 2 bytes as opposed to 4. It also changes ctx->offset and ctx->ninsns to refer to 2-byte instructions rather than 4-byte ones. The riscv PC is required to be 16-bit aligned with or without RVC, so this is sufficient to refer to any valid riscv offset. The code for computing jump offsets in bytes is updated accordingly, and factored into a new "ninsns_rvoff" function to simplify the code. Signed-off-by: Luke Nelson <luke.r.nels@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200721025241.8077-2-luke.r.nels@gmail.com
* bpf, riscv: Optimize BPF_JSET BPF_K using andi on RV64Luke Nelson2020-05-061-8/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch optimizes BPF_JSET BPF_K by using a RISC-V andi instruction when the BPF immediate fits in 12 bits, instead of first loading the immediate to a temporary register. Examples of generated code with and without this optimization: BPF_JMP_IMM(BPF_JSET, R1, 2, 1) without optimization: 20: li t1,2 24: and t1,a0,t1 28: bnez t1,0x30 BPF_JMP_IMM(BPF_JSET, R1, 2, 1) with optimization: 20: andi t1,a0,2 24: bnez t1,0x2c BPF_JMP32_IMM(BPF_JSET, R1, 2, 1) without optimization: 20: li t1,2 24: mv t2,a0 28: slli t2,t2,0x20 2c: srli t2,t2,0x20 30: slli t1,t1,0x20 34: srli t1,t1,0x20 38: and t1,t2,t1 3c: bnez t1,0x44 BPF_JMP32_IMM(BPF_JSET, R1, 2, 1) with optimization: 20: andi t1,a0,2 24: bnez t1,0x2c In these examples, because the upper 32 bits of the sign-extended immediate are 0, BPF_JMP BPF_JSET and BPF_JMP32 BPF_JSET are equivalent and therefore the JIT produces identical code for them. Co-developed-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: Luke Nelson <luke.r.nels@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Björn Töpel <bjorn.topel@gmail.com> Acked-by: Björn Töpel <bjorn.topel@gmail.com> Link: https://lore.kernel.org/bpf/20200506000320.28965-5-luke.r.nels@gmail.com
* bpf, riscv: Optimize BPF_JMP BPF_K when imm == 0 on RV64Luke Nelson2020-05-061-5/+10
| | | | | | | | | | | | | | | | | This patch adds an optimization to BPF_JMP (32- and 64-bit) BPF_K for when the BPF immediate is zero. When the immediate is zero, the code can directly use the RISC-V zero register instead of loading a zero immediate to a temporary register first. Co-developed-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: Luke Nelson <luke.r.nels@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Björn Töpel <bjorn.topel@gmail.com> Acked-by: Björn Töpel <bjorn.topel@gmail.com> Link: https://lore.kernel.org/bpf/20200506000320.28965-4-luke.r.nels@gmail.com
* bpf, riscv: Optimize FROM_LE using verifier_zext on RV64Luke Nelson2020-05-061-6/+14
| | | | | | | | | | | | | | | | | This patch adds two optimizations for BPF_ALU BPF_END BPF_FROM_LE in the RV64 BPF JIT. First, it enables the verifier zero-extension optimization to avoid zero extension when imm == 32. Second, it avoids generating code for imm == 64, since it is equivalent to a no-op. Co-developed-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: Luke Nelson <luke.r.nels@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Björn Töpel <bjorn.topel@gmail.com> Acked-by: Björn Töpel <bjorn.topel@gmail.com> Link: https://lore.kernel.org/bpf/20200506000320.28965-3-luke.r.nels@gmail.com
* bpf, riscv: Enable missing verifier_zext optimizations on RV64Luke Nelson2020-05-061-4/+4
| | | | | | | | | | | | | | | | | | | | | Commit 66d0d5a854a6 ("riscv: bpf: eliminate zero extension code-gen") added support for the verifier zero-extension optimization on RV64 and commit 46dd3d7d287b ("bpf, riscv: Enable zext optimization for more RV64G ALU ops") enabled it for more instruction cases. However, BPF_LSH BPF_X and BPF_{LSH,RSH,ARSH} BPF_K are still missing the optimization. This patch enables the zero-extension optimization for these remaining cases. Co-developed-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: Luke Nelson <luke.r.nels@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Björn Töpel <bjorn.topel@gmail.com> Acked-by: Björn Töpel <bjorn.topel@gmail.com> Link: https://lore.kernel.org/bpf/20200506000320.28965-2-luke.r.nels@gmail.com
* bpf, riscv: Fix stack layout of JITed code on RV32Luke Nelson2020-04-301-33/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes issues with stackframe unwinding and alignment in the current stack layout for BPF programs on RV32. In the current layout, RV32 fp points to the JIT scratch registers, rather than to the callee-saved registers. This breaks stackframe unwinding, which expects fp to point just above the saved ra and fp registers. This patch fixes the issue by moving the callee-saved registers to be stored on the top of the stack, pointed to by fp. This satisfies the assumptions of stackframe unwinding. This patch also fixes an issue with the old layout that the stack was not aligned to 16 bytes. Stacktrace from JITed code using the old stack layout: [ 12.196249 ] [<c0402200>] walk_stackframe+0x0/0x96 Stacktrace using the new stack layout: [ 13.062888 ] [<c0402200>] walk_stackframe+0x0/0x96 [ 13.063028 ] [<c04023c6>] show_stack+0x28/0x32 [ 13.063253 ] [<a403e778>] bpf_prog_82b916b2dfa00464+0x80/0x908 [ 13.063417 ] [<c09270b2>] bpf_test_run+0x124/0x39a [ 13.063553 ] [<c09276c0>] bpf_prog_test_run_skb+0x234/0x448 [ 13.063704 ] [<c048510e>] __do_sys_bpf+0x766/0x13b4 [ 13.063840 ] [<c0485d82>] sys_bpf+0xc/0x14 [ 13.063961 ] [<c04010f0>] ret_from_syscall+0x0/0x2 The new code is also simpler to understand and includes an ASCII diagram of the stack layout. Tested on riscv32 QEMU virt machine. Signed-off-by: Luke Nelson <luke.r.nels@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Xi Wang <xi.wang@gmail.com> Link: https://lore.kernel.org/bpf/20200430005127.2205-1-luke.r.nels@gmail.com
* bpf, riscv: Fix tail call count off by one in RV32 BPF JITLuke Nelson2020-04-261-2/+3
| | | | | | | | | | | | | | This patch fixes an off by one error in the RV32 JIT handling for BPF tail call. Currently, the code decrements TCC before checking if it is less than zero. This limits the maximum number of tail calls to 32 instead of 33 as in other JITs. The fix is to instead check the old value of TCC before decrementing. Fixes: 5f316b65e99f ("riscv, bpf: Add RV32G eBPF JIT") Signed-off-by: Luke Nelson <luke.r.nels@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Xi Wang <xi.wang@gmail.com> Link: https://lore.kernel.org/bpf/20200421002804.5118-1-luke.r.nels@gmail.com
* riscv, bpf: Fix offset range checking for auipc+jalr on RV64Luke Nelson2020-04-081-17/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The existing code in emit_call on RV64 checks that the PC-relative offset to the function fits in 32 bits before calling emit_jump_and_link to emit an auipc+jalr pair. However, this check is incorrect because offsets in the range [2^31 - 2^11, 2^31 - 1] cannot be encoded using auipc+jalr on RV64 (see discussion [1]). The RISC-V spec has recently been updated to reflect this fact [2, 3]. This patch fixes the problem by moving the check on the offset into emit_jump_and_link and modifying it to the correct range of encodable offsets, which is [-2^31 - 2^11, 2^31 - 2^11). This also enforces the check on the offset to other uses of emit_jump_and_link (e.g., BPF_JA) as well. Currently, this bug is unlikely to be triggered, because the memory region from which JITed images are allocated is close enough to kernel text for the offsets to not become too large; and because the bounds on BPF program size are small enough. This patch prevents this problem from becoming an issue if either of these change. [1]: https://groups.google.com/a/groups.riscv.org/forum/#!topic/isa-dev/bwWFhBnnZFQ [2]: https://github.com/riscv/riscv-isa-manual/commit/b1e42e09ac55116dbf9de5e4fb326a5a90e4a993 [3]: https://github.com/riscv/riscv-isa-manual/commit/4c1b2066ebd2965a422e41eb262d0a208a7fea07 Signed-off-by: Luke Nelson <luke.r.nels@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200406221604.18547-1-luke.r.nels@gmail.com
* riscv, bpf: Add RV32G eBPF JITLuke Nelson2020-03-053-1/+1365
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is an eBPF JIT for RV32G, adapted from the JIT for RV64G and the 32-bit ARM JIT. There are two main changes required for this to work compared to the RV64 JIT. First, eBPF registers are 64-bit, while RV32G registers are 32-bit. BPF registers either map directly to 2 RISC-V registers, or reside in stack scratch space and are saved and restored when used. Second, many 64-bit ALU operations do not trivially map to 32-bit operations. Operations that move bits between high and low words, such as ADD, LSH, MUL, and others must emulate the 64-bit behavior in terms of 32-bit instructions. This patch also makes related changes to bpf_jit.h, such as adding RISC-V instructions required by the RV32 JIT. Supported features: The RV32 JIT supports the same features and instructions as the RV64 JIT, with the following exceptions: - ALU64 DIV/MOD: Requires loops to implement on 32-bit hardware. - BPF_XADD | BPF_DW: There's no 8-byte atomic instruction in RV32. These features are also unsupported on other BPF JITs for 32-bit architectures. Testing: - lib/test_bpf.c test_bpf: Summary: 378 PASSED, 0 FAILED, [349/366 JIT'ed] test_bpf: test_skb_segment: Summary: 2 PASSED, 0 FAILED The tests that are not JITed are all due to use of 64-bit div/mod or 64-bit xadd. - tools/testing/selftests/bpf/test_verifier.c Summary: 1415 PASSED, 122 SKIPPED, 43 FAILED Tested both with and without BPF JIT hardening. This is the same set of tests that pass using the BPF interpreter with the JIT disabled. Verification and synthesis: We developed the RV32 JIT using our automated verification tool, Serval. We have used Serval in the past to verify patches to the RV64 JIT. We also used Serval to superoptimize the resulting code through program synthesis. You can find the tool and a guide to the approach and results here: https://github.com/uw-unsat/serval-bpf/tree/rv32-jit-v5 Co-developed-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: Luke Nelson <luke.r.nels@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Björn Töpel <bjorn.topel@gmail.com> Acked-by: Björn Töpel <bjorn.topel@gmail.com> Link: https://lore.kernel.org/bpf/20200305050207.4159-3-luke.r.nels@gmail.com
* riscv, bpf: Factor common RISC-V JIT codeLuke Nelson2020-03-054-601/+639
| | | | | | | | | | | | | | | | | | | | | | | | This patch factors out code that can be used by both the RV64 and RV32 BPF JITs to a common bpf_jit.h and bpf_jit_core.c. Move struct definitions and macro-like functions to header. Rename rv_sb_insn/rv_uj_insn to rv_b_insn/rv_j_insn to match the RISC-V specification. Move reusable functions emit_body() and bpf_int_jit_compile() to bpf_jit_core.c with minor simplifications. Rename emit_insn() and build_{prologue,epilogue}() to be prefixed with "bpf_jit_" as they are no longer static. Rename bpf_jit_comp.c to bpf_jit_comp64.c to be more explicit. Co-developed-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: Luke Nelson <luke.r.nels@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Björn Töpel <bjorn.topel@gmail.com> Acked-by: Björn Töpel <bjorn.topel@gmail.com> Link: https://lore.kernel.org/bpf/20200305050207.4159-2-luke.r.nels@gmail.com
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2019-12-271-238/+293
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann says: ==================== pull-request: bpf-next 2019-12-27 The following pull-request contains BPF updates for your *net-next* tree. We've added 127 non-merge commits during the last 17 day(s) which contain a total of 110 files changed, 6901 insertions(+), 2721 deletions(-). There are three merge conflicts. Conflicts and resolution looks as follows: 1) Merge conflict in net/bpf/test_run.c: There was a tree-wide cleanup c593642c8be0 ("treewide: Use sizeof_field() macro") which gets in the way with b590cb5f802d ("bpf: Switch to offsetofend in BPF_PROG_TEST_RUN"): <<<<<<< HEAD if (!range_is_zero(__skb, offsetof(struct __sk_buff, priority) + sizeof_field(struct __sk_buff, priority), ======= if (!range_is_zero(__skb, offsetofend(struct __sk_buff, priority), >>>>>>> 7c8dce4b166113743adad131b5a24c4acc12f92c There are a few occasions that look similar to this. Always take the chunk with offsetofend(). Note that there is one where the fields differ in here: <<<<<<< HEAD if (!range_is_zero(__skb, offsetof(struct __sk_buff, tstamp) + sizeof_field(struct __sk_buff, tstamp), ======= if (!range_is_zero(__skb, offsetofend(struct __sk_buff, gso_segs), >>>>>>> 7c8dce4b166113743adad131b5a24c4acc12f92c Just take the one with offsetofend() /and/ gso_segs. Latter is correct due to 850a88cc4096 ("bpf: Expose __sk_buff wire_len/gso_segs to BPF_PROG_TEST_RUN"). 2) Merge conflict in arch/riscv/net/bpf_jit_comp.c: (I'm keeping Bjorn in Cc here for a double-check in case I got it wrong.) <<<<<<< HEAD if (is_13b_check(off, insn)) return -1; emit(rv_blt(tcc, RV_REG_ZERO, off >> 1), ctx); ======= emit_branch(BPF_JSLT, RV_REG_T1, RV_REG_ZERO, off, ctx); >>>>>>> 7c8dce4b166113743adad131b5a24c4acc12f92c Result should look like: emit_branch(BPF_JSLT, tcc, RV_REG_ZERO, off, ctx); 3) Merge conflict in arch/riscv/include/asm/pgtable.h: <<<<<<< HEAD ======= #define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1) #define VMALLOC_END (PAGE_OFFSET - 1) #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) #define BPF_JIT_REGION_SIZE (SZ_128M) #define BPF_JIT_REGION_START (PAGE_OFFSET - BPF_JIT_REGION_SIZE) #define BPF_JIT_REGION_END (VMALLOC_END) /* * Roughly size the vmemmap space to be large enough to fit enough * struct pages to map half the virtual address space. Then * position vmemmap directly below the VMALLOC region. */ #define VMEMMAP_SHIFT \ (CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT) #define VMEMMAP_SIZE BIT(VMEMMAP_SHIFT) #define VMEMMAP_END (VMALLOC_START - 1) #define VMEMMAP_START (VMALLOC_START - VMEMMAP_SIZE) #define vmemmap ((struct page *)VMEMMAP_START) >>>>>>> 7c8dce4b166113743adad131b5a24c4acc12f92c Only take the BPF_* defines from there and move them higher up in the same file. Remove the rest from the chunk. The VMALLOC_* etc defines got moved via 01f52e16b868 ("riscv: define vmemmap before pfn_to_page calls"). Result: [...] #define __S101 PAGE_READ_EXEC #define __S110 PAGE_SHARED_EXEC #define __S111 PAGE_SHARED_EXEC #define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1) #define VMALLOC_END (PAGE_OFFSET - 1) #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) #define BPF_JIT_REGION_SIZE (SZ_128M) #define BPF_JIT_REGION_START (PAGE_OFFSET - BPF_JIT_REGION_SIZE) #define BPF_JIT_REGION_END (VMALLOC_END) /* * Roughly size the vmemmap space to be large enough to fit enough * struct pages to map half the virtual address space. Then * position vmemmap directly below the VMALLOC region. */ #define VMEMMAP_SHIFT \ (CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT) #define VMEMMAP_SIZE BIT(VMEMMAP_SHIFT) #define VMEMMAP_END (VMALLOC_START - 1) #define VMEMMAP_START (VMALLOC_START - VMEMMAP_SIZE) [...] Let me know if there are any other issues. Anyway, the main changes are: 1) Extend bpftool to produce a struct (aka "skeleton") tailored and specific to a provided BPF object file. This provides an alternative, simplified API compared to standard libbpf interaction. Also, add libbpf extern variable resolution for .kconfig section to import Kconfig data, from Andrii Nakryiko. 2) Add BPF dispatcher for XDP which is a mechanism to avoid indirect calls by generating a branch funnel as discussed back in bpfconf'19 at LSF/MM. Also, add various BPF riscv JIT improvements, from Björn Töpel. 3) Extend bpftool to allow matching BPF programs and maps by name, from Paul Chaignon. 4) Support for replacing cgroup BPF programs attached with BPF_F_ALLOW_MULTI flag for allowing updates without service interruption, from Andrey Ignatov. 5) Cleanup and simplification of ring access functions for AF_XDP with a bonus of 0-5% performance improvement, from Magnus Karlsson. 6) Enable BPF JITs for x86-64 and arm64 by default. Also, final version of audit support for BPF, from Daniel Borkmann and latter with Jiri Olsa. 7) Move and extend test_select_reuseport into BPF program tests under BPF selftests, from Jakub Sitnicki. 8) Various BPF sample improvements for xdpsock for customizing parameters to set up and benchmark AF_XDP, from Jay Jayatheerthan. 9) Improve libbpf to provide a ulimit hint on permission denied errors. Also change XDP sample programs to attach in driver mode by default, from Toke Høiland-Jørgensen. 10) Extend BPF test infrastructure to allow changing skb mark from tc BPF programs, from Nikita V. Shirokov. 11) Optimize prologue code sequence in BPF arm32 JIT, from Russell King. 12) Fix xdp_redirect_cpu BPF sample to manually attach to tracepoints after libbpf conversion, from Jesper Dangaard Brouer. 13) Minor misc improvements from various others. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * riscv, bpf: Optimize callsBjörn Töpel2019-12-191-37/+64
| | | | | | | | | | | | | | | | | | Instead of using emit_imm() and emit_jalr() which can expand to six instructions, start using jal or auipc+jalr. Signed-off-by: Björn Töpel <bjorn.topel@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191216091343.23260-8-bjorn.topel@gmail.com
| * riscv, bpf: Provide RISC-V specific JIT image alloc/freeBjörn Töpel2019-12-191-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | This commit makes sure that the JIT images is kept close to the kernel text, so BPF calls can use relative calling with auipc/jalr or jal instead of loading the full 64-bit address and jalr. The BPF JIT image region is 128 MB before the kernel text. Signed-off-by: Björn Töpel <bjorn.topel@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191216091343.23260-7-bjorn.topel@gmail.com
| * riscv, bpf: Optimize BPF tail callsBjörn Töpel2019-12-191-6/+7
| | | | | | | | | | | | | | | | Remove one addi, and instead use the offset part of jalr. Signed-off-by: Björn Töpel <bjorn.topel@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191216091343.23260-6-bjorn.topel@gmail.com
| * riscv, bpf: Add support for far jumps and exitsBjörn Töpel2019-12-191-20/+17
| | | | | | | | | | | | | | | | | | This commit add support for far (offset > 21b) jumps and exits. Signed-off-by: Björn Töpel <bjorn.topel@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Luke Nelson <lukenels@cs.washington.edu> Link: https://lore.kernel.org/bpf/20191216091343.23260-5-bjorn.topel@gmail.com
| * riscv, bpf: Add support for far branching when emitting tail callBjörn Töpel2019-12-191-19/+3
| | | | | | | | | | | | | | | | | | Start use the emit_branch() function in the tail call emitter in order to support far branching. Signed-off-by: Björn Töpel <bjorn.topel@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191216091343.23260-4-bjorn.topel@gmail.com
| * riscv, bpf: Add support for far branchingBjörn Töpel2019-12-191-164/+188
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit adds branch relaxation to the BPF JIT, and with that support for far (offset greater than 12b) branching. The branch relaxation requires more than two passes to converge. For most programs it is three passes, but for larger programs it can be more. Signed-off-by: Björn Töpel <bjorn.topel@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Luke Nelson <lukenels@cs.washington.edu> Link: https://lore.kernel.org/bpf/20191216091343.23260-3-bjorn.topel@gmail.com
| * riscv, bpf: Fix broken BPF tail callsBjörn Töpel2019-12-191-2/+11
| | | | | | | | | | | | | | | | | | | | The BPF JIT incorrectly clobbered the a0 register, and did not flag usage of s5 register when BPF stack was being used. Fixes: 2353ecc6f91f ("bpf, riscv: add BPF JIT for RV64G") Signed-off-by: Björn Töpel <bjorn.topel@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191216091343.23260-2-bjorn.topel@gmail.com
* | bpf, riscv: Limit to 33 tail callsPaul Chaignon2019-12-111-2/+2
|/ | | | | | | | | | | | | | | | | | All BPF JIT compilers except RISC-V's and MIPS' enforce a 33-tail calls limit at runtime. In addition, a test was recently added, in tailcalls2, to check this limit. This patch updates the tail call limit in RISC-V's JIT compiler to allow 33 tail calls. I tested it using the above selftest on an emulated RISCV64. Fixes: 2353ecc6f91f ("bpf, riscv: add BPF JIT for RV64G") Reported-by: Mahshid Khezri <khezri.mahshid@gmail.com> Signed-off-by: Paul Chaignon <paul.chaignon@orange.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/966fe384383bf23a0ee1efe8d7291c78a3fb832b.1575916815.git.paul.chaignon@gmail.com
* bpf, riscv: Enable zext optimization for more RV64G ALU opsLuke Nelson2019-07-051-8/+8
| | | | | | | | | | | | | | | | | | | | | | Commit 66d0d5a854a6 ("riscv: bpf: eliminate zero extension code-gen") added the new zero-extension optimization for some BPF ALU operations. Since then, bugs in the JIT that have been fixed in the bpf tree require this optimization to be added to other operations: commit 1e692f09e091 ("bpf, riscv: clear high 32 bits for ALU32 add/sub/neg/lsh/rsh/arsh"), and commit fe121ee531d1 ("bpf, riscv: clear target register high 32-bits for and/or/xor on ALU32"). Now that these have been merged to bpf-next, the zext optimization can be enabled for the fixed operations. Signed-off-by: Luke Nelson <luke.r.nels@gmail.com> Cc: Song Liu <liu.song.a23@gmail.com> Cc: Jiong Wang <jiong.wang@netronome.com> Cc: Xi Wang <xi.wang@gmail.com> Acked-by: Björn Töpel <bjorn.topel@gmail.com> Acked-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2019-06-181-0/+24
|\ | | | | | | | | | | | | Honestly all the conflicts were simple overlapping changes, nothing really interesting to report. Signed-off-by: David S. Miller <davem@davemloft.net>
| * Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller2019-06-071-0/+24
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann says: ==================== pull-request: bpf 2019-06-07 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) Fix several bugs in riscv64 JIT code emission which forgot to clear high 32-bits for alu32 ops, from Björn and Luke with selftests covering all relevant BPF alu ops from Björn and Jiong. 2) Two fixes for UDP BPF reuseport that avoid calling the program in case of __udp6_lib_err and UDP GRO which broke reuseport_select_sock() assumption that skb->data is pointing to transport header, from Martin. 3) Two fixes for BPF sockmap: a use-after-free from sleep in psock's backlog workqueue, and a missing restore of sk_write_space when psock gets dropped, from Jakub and John. 4) Fix unconnected UDP sendmsg hook API which is insufficient as-is since it breaks standard applications like DNS if reverse NAT is not performed upon receive, from Daniel. 5) Fix an out-of-bounds read in __bpf_skc_lookup which in case of AF_INET6 fails to verify that the length of the tuple is long enough, from Lorenz. 6) Fix libbpf's libbpf__probe_raw_btf to return an fd instead of 0/1 (for {un,}successful probe) as that is expected to be propagated as an fd to load_sk_storage_btf() and thus closing the wrong descriptor otherwise, from Michal. 7) Fix bpftool's JSON output for the case when a lookup fails, from Krzesimir. 8) Minor misc fixes in docs, samples and selftests, from various others. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| | * bpf, riscv: clear high 32 bits for ALU32 add/sub/neg/lsh/rsh/arshLuke Nelson2019-06-011-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In BPF, 32-bit ALU operations should zero-extend their results into the 64-bit registers. The current BPF JIT on RISC-V emits incorrect instructions that perform sign extension only (e.g., addw, subw) on 32-bit add, sub, lsh, rsh, arsh, and neg. This behavior diverges from the interpreter and JITs for other architectures. This patch fixes the bugs by performing zero extension on the destination register of 32-bit ALU operations. Fixes: 2353ecc6f91f ("bpf, riscv: add BPF JIT for RV64G") Cc: Xi Wang <xi.wang@gmail.com> Signed-off-by: Luke Nelson <luke.r.nels@gmail.com> Acked-by: Song Liu <songliubraving@fb.com> Acked-by: Björn Töpel <bjorn.topel@gmail.com> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| | * bpf, riscv: clear target register high 32-bits for and/or/xor on ALU32Björn Töpel2019-05-231-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When using 32-bit subregisters (ALU32), the RISC-V JIT would not clear the high 32-bits of the target register and therefore generate incorrect code. E.g., in the following code: $ cat test.c unsigned int f(unsigned long long a, unsigned int b) { return (unsigned int)a & b; } $ clang-9 -target bpf -O2 -emit-llvm -S test.c -o - | \ llc-9 -mattr=+alu32 -mcpu=v3 .text .file "test.c" .globl f .p2align 3 .type f,@function f: r0 = r1 w0 &= w2 exit .Lfunc_end0: .size f, .Lfunc_end0-f The JIT would not clear the high 32-bits of r0 after the and-operation, which in this case might give an incorrect return value. After this patch, that is not the case, and the upper 32-bits are cleared. Reported-by: Jiong Wang <jiong.wang@netronome.com> Fixes: 2353ecc6f91f ("bpf, riscv: add BPF JIT for RV64G") Signed-off-by: Björn Töpel <bjorn.topel@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | | riscv: bpf: eliminate zero extension code-genJiong Wang2019-05-251-13/+30
|/ / | | | | | | | | | | | | | | Cc: Björn Töpel <bjorn.topel@gmail.com> Acked-by: Björn Töpel <bjorn.topel@gmail.com> Tested-by: Björn Töpel <bjorn.topel@gmail.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* / treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner2019-05-211-0/+1
|/ | | | | | | | | | | | | | Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bpf, riscv: add BPF JIT for RV64GBjörn Töpel2019-02-052-0/+1603
This commit adds a BPF JIT for RV64G. The JIT is a two-pass JIT, and has a dynamic prolog/epilogue (similar to the MIPS64 BPF JIT) instead of static ones (e.g. x86_64). At the moment the RISC-V Linux port does not support CONFIG_HAVE_KPROBES, which means that CONFIG_BPF_EVENTS is not supported. Thus, no tests involving BPF_PROG_TYPE_TRACEPOINT, BPF_PROG_TYPE_PERF_EVENT, BPF_PROG_TYPE_KPROBE and BPF_PROG_TYPE_RAW_TRACEPOINT passes. The implementation does not support "far branching" (>4KiB). Test results: # modprobe test_bpf test_bpf: Summary: 378 PASSED, 0 FAILED, [366/366 JIT'ed] # echo 1 > /proc/sys/kernel/unprivileged_bpf_disabled # ./test_verifier ... Summary: 761 PASSED, 507 SKIPPED, 2 FAILED Note that "test_verifier" was run with one build with CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS=y and one without, otherwise many of the the tests that require unaligned access were skipped. CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS=y: # echo 1 > /proc/sys/kernel/unprivileged_bpf_disabled # ./test_verifier | grep -c 'NOTE.*unknown align' 0 No CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS: # echo 1 > /proc/sys/kernel/unprivileged_bpf_disabled # ./test_verifier | grep -c 'NOTE.*unknown align' 59 The two failing test_verifier tests are: "ld_abs: vlan + abs, test 1" "ld_abs: jump around ld_abs" This is due to that "far branching" involved in those tests. All tests where done on QEMU (QEMU emulator version 3.1.50 (v3.1.0-688-g8ae951fbc106)). Signed-off-by: Björn Töpel <bjorn.topel@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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