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2020-03-20bpf, mips: Limit to 33 tail callsPaul Chaignon
commit e49e6f6db04e915dccb494ae10fa14888fea6f89 upstream. 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 MIPS' JIT compiler to allow 33 tail calls. Fixes: b6bd53f9c4e8 ("MIPS: Add missing file for eBPF JIT.") 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: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/b8eb2caac1c25453c539248e56ca22f74b5316af.1575916815.git.paul.chaignon@gmail.com Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-03-20MIPS: BPF: eBPF JIT: check for MIPS ISA compliance in KconfigAlexander Lobakin
commit f596cf0d8062cb5d0a4513a8b3afca318c13be10 upstream. It is completely wrong to check for compile-time MIPS ISA revision in the body of bpf_int_jit_compile() as it may lead to get MIPS JIT fully omitted by the CC while the rest system will think that the JIT is actually present and works [1]. We can check if the selected CPU really supports MIPS eBPF JIT at configure time and avoid such situations when kernel can be built without both JIT and interpreter, but with CONFIG_BPF_SYSCALL=y. [1] https://lore.kernel.org/linux-mips/09d713a59665d745e21d021deeaebe0a@dlink.ru/ Fixes: 716850ab104d ("MIPS: eBPF: Initial eBPF support for MIPS32 architecture.") Cc: <stable@vger.kernel.org> # v5.2+ Signed-off-by: Alexander Lobakin <alobakin@dlink.ru> Signed-off-by: Paul Burton <paulburton@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: Hassan Naveed <hnaveed@wavecomp.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Song Liu <songliubraving@fb.com> Cc: Yonghong Song <yhs@fb.com> Cc: Andrii Nakryiko <andriin@fb.com> Cc: linux-mips@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: netdev@vger.kernel.org Cc: bpf@vger.kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 of the license extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 315 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-08Merge tag 'mips_5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linuxLinus Torvalds
Pull MIPS updates from Paul Burton: - A set of memblock initialization improvements thanks to Serge Semin, tidying up after our conversion from bootmem to memblock back in v4.20. - Our eBPF JIT the previously supported only MIPS64r2 through MIPS64r5 is improved to also support MIPS64r6. Support for MIPS32 systems is introduced, with the caveat that it only works for programs that don't use 64 bit registers or operations - those will bail out & need to be interpreted. - Improvements to the allocation & configuration of our exception vector that should fix issues seen on some platforms using recent versions of U-Boot. - Some minor improvements to code generated for jump labels, along with enabling them by default for generic kernels. * tag 'mips_5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (27 commits) mips: Manually call fdt_init_reserved_mem() method mips: Make sure dt memory regions are valid mips: Perform early low memory test mips: Dump memblock regions for debugging mips: Add reserve-nomap memory type support mips: Use memblock to reserve the __nosave memory range mips: Discard post-CMA-init foreach loop mips: Reserve memory for the kernel image resources MIPS: Remove duplicate EBase configuration MIPS: Sync icache for whole exception vector MIPS: Always allocate exception vector for MIPSr2+ MIPS: Use memblock_phys_alloc() for exception vector mips: Combine memblock init and memory reservation loops mips: Discard rudiments from bootmem_init mips: Make sure kernel .bss exists in boot mem pool mips: vdso: drop unnecessary cc-ldoption Revert "MIPS: ralink: fix cpu clock of mt7621 and add dt clk devices" MIPS: generic: Enable CONFIG_JUMP_LABEL MIPS: jump_label: Use compact branches for >= r6 MIPS: jump_label: Remove redundant nops ...
2019-04-25MIPS: eBPF: Make ebpf_to_mips_reg() staticYueHaibing
Fix sparse warning: arch/mips/net/ebpf_jit.c:196:5: warning: symbol 'ebpf_to_mips_reg' was not declared. Should it be static? Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: YueHaibing <yuehaibing@huawei.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-03-19MIPS: eBPF: Initial eBPF support for MIPS32 architecture.Hassan Naveed
Currently MIPS32 supports a JIT for classic BPF only, not extended BPF. This patch adds JIT support for extended BPF on MIPS32, so code is actually JIT'ed instead of being only interpreted. Instructions with 64-bit operands are not supported at this point. We can delete classic BPF because the kernel will translate classic BPF programs into extended BPF and JIT them, eliminating the need for classic BPF. Signed-off-by: Hassan Naveed <hnaveed@wavecomp.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: kafai@fb.com Cc: songliubraving@fb.com Cc: yhs@fb.com Cc: netdev@vger.kernel.org Cc: bpf@vger.kernel.org Cc: linux-mips@vger.kernel.org Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: open list:MIPS <linux-mips@linux-mips.org> Cc: open list <linux-kernel@vger.kernel.org>
2019-03-19MIPS: eBPF: Provide eBPF support for MIPS64R6Hassan Naveed
Currently eBPF support is available on MIPS64R2 only. Use MIPS64R6 variants of instructions like multiply, divide, movn, movz so eBPF can run on the newer ISA. Also, we only need to check ISA revision before JIT'ing code, because we know the CPU is running a 64-bit kernel because eBPF JIT is only included in kernels with CONFIG_64BIT=y due to Kconfig dependencies. Signed-off-by: Hassan Naveed <hnaveed@wavecomp.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: kafai@fb.com Cc: songliubraving@fb.com Cc: yhs@fb.com Cc: netdev@vger.kernel.org Cc: bpf@vger.kernel.org Cc: linux-mips@vger.kernel.org Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: open list:MIPS <linux-mips@linux-mips.org> Cc: open list <linux-kernel@vger.kernel.org>
2019-03-02MIPS: eBPF: Fix icache flush end addressPaul Burton
The MIPS eBPF JIT calls flush_icache_range() in order to ensure the icache observes the code that we just wrote. Unfortunately it gets the end address calculation wrong due to some bad pointer arithmetic. The struct jit_ctx target field is of type pointer to u32, and as such adding one to it will increment the address being pointed to by 4 bytes. Therefore in order to find the address of the end of the code we simply need to add the number of 4 byte instructions emitted, but we mistakenly add the number of instructions multiplied by 4. This results in the call to flush_icache_range() operating on a memory region 4x larger than intended, which is always wasteful and can cause crashes if we overrun into an unmapped page. Fix this by correcting the pointer arithmetic to remove the bogus multiplication, and use braces to remove the need for a set of brackets whilst also making it obvious that the target field is a pointer. Signed-off-by: Paul Burton <paul.burton@mips.com> Fixes: b6bd53f9c4e8 ("MIPS: Add missing file for eBPF JIT.") Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Song Liu <songliubraving@fb.com> Cc: Yonghong Song <yhs@fb.com> Cc: netdev@vger.kernel.org Cc: bpf@vger.kernel.org Cc: linux-mips@vger.kernel.org Cc: stable@vger.kernel.org # v4.13+ Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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>