From 2353ecc6f91fd15b893fa01bf85a1c7a823ee4f2 Mon Sep 17 00:00:00 2001 From: Björn Töpel Date: Tue, 5 Feb 2019 13:41:22 +0100 Subject: bpf, riscv: add BPF JIT for RV64G MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Daniel Borkmann --- arch/riscv/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/riscv/Makefile') diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index 4b594f2e4f7e..c6342e638ef7 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -77,7 +77,7 @@ KBUILD_IMAGE := $(boot)/Image.gz head-y := arch/riscv/kernel/head.o -core-y += arch/riscv/kernel/ arch/riscv/mm/ +core-y += arch/riscv/kernel/ arch/riscv/mm/ arch/riscv/net/ libs-y += arch/riscv/lib/ -- cgit v1.2.3-59-g8ed1b