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path: root/arch/mips/net/ebpf_jit.c
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2019-02-16MIPS: eBPF: Remove REG_32BIT_ZERO_EXPaul Burton
REG_32BIT_ZERO_EX and REG_64BIT are always handled in exactly the same way, and reg_val_propagate_range() never actually sets any register to type REG_32BIT_ZERO_EX. Remove the redundant & unused REG_32BIT_ZERO_EX. Signed-off-by: Paul Burton <paul.burton@mips.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-16MIPS: eBPF: Always return sign extended 32b valuesPaul Burton
The function prototype used to call JITed eBPF code (ie. the type of the struct bpf_prog bpf_func field) returns an unsigned int. The MIPS n64 ABI that MIPS64 kernels target defines that 32 bit integers should always be sign extended when passed in registers as either arguments or return values. This means that when returning any value which may not already be sign extended (ie. of type REG_64BIT or REG_32BIT_ZERO_EX) we need to perform that sign extension in order to comply with the n64 ABI. Without this we see strange looking test failures from test_bpf.ko, such as: test_bpf: #65 ALU64_MOV_X: dst = 4294967295 jited:1 ret -1 != -1 FAIL (1 times) Although the return value printed matches the expected value, this is only because printf is only examining the least significant 32 bits of the 64 bit register value we returned. The register holding the expected value is sign extended whilst the v0 register was set to a zero extended value by our JITed code, so when compared by a conditional branch instruction the values are not equal. We already handle this when the return value register is of type REG_32BIT_ZERO_EX, so simply extend this to also cover REG_64BIT. Signed-off-by: Paul Burton <paul.burton@mips.com> Fixes: b6bd53f9c4e8 ("MIPS: Add missing file for eBPF JIT.") Cc: stable@vger.kernel.org # v4.13+ Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-07mips: bpf: implement jitting of BPF_ALU | BPF_ARSH | BPF_XJiong Wang
Jitting of BPF_K is supported already, but not BPF_X. This patch complete the support for the latter on both MIPS and microMIPS. Cc: Paul Burton <paul.burton@mips.com> Cc: linux-mips@vger.kernel.org Acked-by: Paul Burton <paul.burton@mips.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-05-14bpf, mips: remove unused functionDaniel Borkmann
The ool_skb_header_pointer() and size_to_len() is unused same as tmp_offset, therefore remove all of them. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-05-03bpf, mips64: remove ld_abs/ld_indDaniel Borkmann
Since LD_ABS/LD_IND instructions are now removed from the core and reimplemented through a combination of inlined BPF instructions and a slow-path helper, we can get rid of the complexity from mips64 JIT. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-26bpf, mips64: remove unneeded zero check from div/mod with kDaniel Borkmann
The verifier in both cBPF and eBPF reject div/mod by 0 imm, so this can never load. Remove emitting such test and reject it from being JITed instead (the latter is actually also not needed, but given practice in sparc64, ppc64 today, so doesn't hurt to add it here either). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: David Daney <david.daney@cavium.com> Reviewed-by: David Daney <david.daney@cavium.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-26bpf, mips64: remove obsolete exception handling from div/modDaniel Borkmann
Since we've changed div/mod exception handling for src_reg in eBPF verifier itself, remove the leftovers from mips64 JIT. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: David Daney <david.daney@cavium.com> Reviewed-by: David Daney <david.daney@cavium.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-19bpf: get rid of pure_initcall dependency to enable jitsDaniel Borkmann
Having a pure_initcall() callback just to permanently enable BPF JITs under CONFIG_BPF_JIT_ALWAYS_ON is unnecessary and could leave a small race window in future where JIT is still disabled on boot. Since we know about the setting at compilation time anyway, just initialize it properly there. Also consolidate all the individual bpf_jit_enable variables into a single one and move them under one location. Moreover, don't allow for setting unspecified garbage values on them. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-17bpf: fix net.core.bpf_jit_enable raceAlexei Starovoitov
global bpf_jit_enable variable is tested multiple times in JITs, blinding and verifier core. The malicious root can try to toggle it while loading the programs. This race condition was accounted for and there should be no issues, but it's safer to avoid this race condition. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-11-01MIPS: bpf: Fix a typo in build_one_insn()Wei Yongjun
Fix a typo in build_one_insn(). Fixes: b6bd53f9c4e8 ("MIPS: Add missing file for eBPF JIT.") Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Cc: <stable@vger.kernel.org> # 4.13+ Patchwork: https://patchwork.linux-mips.org/patch/17491/ Signed-off-by: James Hogan <jhogan@kernel.org>
2017-10-09MIPS: bpf: Fix uninitialised target compiler errorMatt Redfearn
Compiling ebpf_jit.c with gcc 4.9 results in a (likely spurious) compiler warning, as gcc has detected that the variable "target" may be used uninitialised. Since -Werror is active, this is treated as an error and causes a kernel build failure whenever CONFIG_MIPS_EBPF_JIT is enabled. arch/mips/net/ebpf_jit.c: In function 'build_one_insn': arch/mips/net/ebpf_jit.c:1118:80: error: 'target' may be used uninitialized in this function [-Werror=maybe-uninitialized] emit_instr(ctx, j, target); ^ cc1: all warnings being treated as errors Fix this by initialising "target" to 0. If it really is used uninitialised this would result in a jump to 0 and a detectable run time failure. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Fixes: b6bd53f9c4e8 ("MIPS: Add missing file for eBPF JIT.") Cc: James Hogan <james.hogan@imgtec.com> Cc: David Daney <david.daney@cavium.com> Cc: David S. Miller <davem@davemloft.net> Cc: Colin Ian King <colin.king@canonical.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: <stable@vger.kernel.org> # v4.13+ Patchwork: https://patchwork.linux-mips.org/patch/17375/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-08-22MIPS,bpf: fix missing break in switch statementColin Ian King
There is a missing break causing a fall-through and setting ctx.use_bbit_insns to the wrong value. Fix this by adding the missing break. Detected with cppcheck: "Variable 'ctx.use_bbit_insns' is reassigned a value before the old one has been used. 'break;' missing?" Fixes: 8d8d18c3283f ("MIPS,bpf: Fix using smp_processor_id() in preemptible splat.") Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: David Daney <david.daney@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-21MIPS,bpf: Cache value of BPF_OP(insn->code) in eBPF JIT.David Daney
The code looks a little cleaner if we replace BPF_OP(insn->code) with the local variable bpf_op. Caching the value this way also saves 300 bytes (about 1%) in the code size of the JIT. Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-21MIPS, bpf: Implement JLT, JLE, JSLT and JSLE ops in the eBPF JIT.David Daney
Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-21MIPS,bpf: Fix using smp_processor_id() in preemptible splat.David Daney
If the kernel is configured with preemption enabled we were getting warning stack traces for use of current_cpu_type(). Fix by moving the test between preempt_disable()/preempt_enable() and caching the results of the CPU type tests for use during code generation. Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04MIPS: Add missing file for eBPF JIT.David Daney
Inexplicably, commit f381bf6d82f0 ("MIPS: Add support for eBPF JIT.") lost a file somewhere on its path to Linus' tree. Add back the missing ebpf_jit.c so that we can build with CONFIG_BPF_JIT selected. This version of ebpf_jit.c is identical to the original except for two minor change need to resolve conflicts with changes merged from the BPF branch: A) Set prog->jited_len = image_size; B) Use BPF_TAIL_CALL instead of BPF_CALL | BPF_X Fixes: f381bf6d82f0 ("MIPS: Add support for eBPF JIT.") Signed-off-by: David Daney <david.daney@cavium.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>