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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
2020-01-10MIPS: BPF: Use sizeof_field() instead of FIELD_SIZEOF()Kees Cook
The FIELD_SIZEOF() macro was redundant, and is being removed from the kernel. Since commit c593642c8be0 ("treewide: Use sizeof_field() macro") this is one of the last users of the old macro, so replace it. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Paul Burton <paulburton@kernel.org> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@vger.kernel.org
2020-01-09MIPS: BPF: Restore MIPS32 cBPF JITPaul Burton
Commit 716850ab104d ("MIPS: eBPF: Initial eBPF support for MIPS32 architecture.") enabled our eBPF JIT for MIPS32 kernels, whereas it has previously only been availailable for MIPS64. It was my understanding at the time that the BPF test suite was passing & JITing a comparable number of tests to our cBPF JIT [1], but it turns out that was not the case. The eBPF JIT has a number of problems on MIPS32: - Most notably various code paths still result in emission of MIPS64 instructions which will cause reserved instruction exceptions & kernel panics when run on MIPS32 CPUs. - The eBPF JIT doesn't account for differences between the O32 ABI used by MIPS32 kernels versus the N64 ABI used by MIPS64 kernels. Notably arguments beyond the first 4 are passed on the stack in O32, and this is entirely unhandled when JITing a BPF_CALL instruction. Stack space must be reserved for arguments even if they all fit in registers, and the callee is free to assume that stack space has been reserved for its use - with the eBPF JIT this is not the case, so calling any function can result in clobbering values on the stack & unpredictable behaviour. Function arguments in eBPF are always 64-bit values which is also entirely unhandled - the JIT still uses a single (32-bit) register per argument. As a result all function arguments are always passed incorrectly when JITing a BPF_CALL instruction, leading to kernel crashes or strange behavior. - The JIT attempts to bail our on use of ALU64 instructions or 64-bit memory access instructions. The code doing this at the start of build_one_insn() incorrectly checks whether BPF_OP() equals BPF_DW, when it should really be checking BPF_SIZE() & only doing so when BPF_CLASS() is one of BPF_{LD,LDX,ST,STX}. This results in false positives that cause more bailouts than intended, and that in turns hides some of the problems described above. - The kernel's cBPF->eBPF translation makes heavy use of 64-bit eBPF instructions that the MIPS32 eBPF JIT bails out on, leading to most cBPF programs not being JITed at all. Until these problems are resolved, revert the removal of the cBPF JIT performed by commit 716850ab104d ("MIPS: eBPF: Initial eBPF support for MIPS32 architecture."). Together with commit f8fffebdea75 ("MIPS: BPF: Disable MIPS32 eBPF JIT") this restores MIPS32 BPF JIT behavior back to the same state it was prior to the introduction of the broken eBPF JIT support. [1] https://lore.kernel.org/linux-mips/MWHPR2201MB13583388481F01A422CE7D66D4410@MWHPR2201MB1358.namprd22.prod.outlook.com/ Signed-off-by: Paul Burton <paulburton@kernel.org> Fixes: 716850ab104d ("MIPS: eBPF: Initial eBPF support for MIPS32 architecture.") Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Hassan Naveed <hnaveed@wavecomp.com> Cc: Tony Ambardar <itugrok@yahoo.com> Cc: bpf@vger.kernel.org Cc: netdev@vger.kernel.org Cc: linux-mips@vger.kernel.org Cc: linux-kernel@vger.kernel.org
2020-01-04Merge tag 'mips_fixes_5.5_1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux Pull MIPS fixes from Paul Burton: "A collection of MIPS fixes: - Fill the struct cacheinfo shared_cpu_map field with sensible values, notably avoiding issues with perf which was unhappy in the absence of these values. - A boot fix for Loongson 2E & 2F machines which was fallout from some refactoring performed this cycle. - A Kconfig dependency fix for the Loongson CPU HWMon driver. - A couple of VDSO fixes, ensuring gettimeofday() behaves appropriately for kernel configurations that don't include support for a clocksource the VDSO can use & fixing the calling convention for the n32 & n64 VDSOs which would previously clobber the $gp/$28 register. - A build fix for vmlinuz compressed images which were inappropriately building with -fsanitize-coverage despite not being part of the kernel proper, then failing to link due to the missing __sanitizer_cov_trace_pc() function. - A couple of eBPF JIT fixes, including disabling it for MIPS32 due to a large number of issues with the code generated there & reflecting ISA dependencies in Kconfig to enforce that systems which don't support the JIT must include the interpreter" * tag 'mips_fixes_5.5_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: MIPS: Avoid VDSO ABI breakage due to global register variable MIPS: BPF: eBPF JIT: check for MIPS ISA compliance in Kconfig MIPS: BPF: Disable MIPS32 eBPF JIT MIPS: Prevent link failure with kcov instrumentation MIPS: Kconfig: Use correct form for 'depends on' mips: Fix gettimeofday() in the vdso library MIPS: Fix boot on Fuloong2 systems mips: cacheinfo: report shared CPU map
2019-12-18MIPS: BPF: eBPF JIT: check for MIPS ISA compliance in KconfigAlexander Lobakin
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
2019-12-11bpf, mips: Limit to 33 tail callsPaul Chaignon
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
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>
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner
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>
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>
2018-11-16net: remove VLAN_TAG_PRESENTMichał Mirosław
Replace VLAN_TAG_PRESENT with single bit flag and free up VLAN.CFI overload. Now VLAN.CFI is visible in networking stack and can be passed around intact. Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-16net/bpf_jit: MIPS: split VLAN_PRESENT bit handling from VLAN_TCIMichał Mirosław
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Signed-off-by: David S. Miller <davem@davemloft.net>
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>
2018-03-09MIPS: BPF: Replace __mips_isa_rev with MIPS_ISA_REVMatt Redfearn
Remove the need to check that __mips_isa_rev is defined by using the newly added MIPS_ISA_REV. Signed-off-by: Matt Redfearn <matt.redfearn@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: David Daney <david.daney@cavium.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/18677/ Signed-off-by: James Hogan <jhogan@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>
2017-06-28MIPS: Add support for eBPF JIT.David Daney
Since the eBPF machine has 64-bit registers, we only support this in 64-bit kernels. As of the writing of this commit log test-bpf is showing: test_bpf: Summary: 316 PASSED, 0 FAILED, [308/308 JIT'ed] All current test cases are successfully compiled. Many examples in samples/bpf are usable, specifically tracex5 which uses tail calls works. Signed-off-by: David Daney <david.daney@cavium.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16369/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-04-10MIPS: BPF: Fix multiple problems in JIT skb access helpers.David Daney
o Socket data is unsigned, so use unsigned accessors instructions. o Fix path result pointer generation arithmetic. o Fix half-word byte swapping code for unsigned semantics. Signed-off-by: David Daney <david.daney@cavium.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Steven J. Hill <steven.hill@cavium.com> Cc: linux-mips@linux-mips.org Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/15747/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-04-10MIPS: BPF: Quit clobbering callee saved registers in JIT code.David Daney
If bpf_needs_clear_a() returns true, only actually clear it if it is ever used. If it is not used, we don't save and restore it, so the clearing has the nasty side effect of clobbering caller state. Also, don't emit stack pointer adjustment instructions if the adjustment amount is zero. Signed-off-by: David Daney <david.daney@cavium.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Steven J. Hill <steven.hill@cavium.com> Cc: linux-mips@linux-mips.org Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/15745/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-04-10MIPS: BPF: Use unsigned access for unsigned SKB fields.David Daney
The SKB vlan_tci and queue_mapping fields are unsigned, don't sign extend these in the BPF JIT. In the vlan_tci case, the value gets masked so the change is not needed for correctness, but do it anyway for agreement with the types defined in struct sk_buff. Signed-off-by: David Daney <david.daney@cavium.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Steven J. Hill <steven.hill@cavium.com> Cc: linux-mips@linux-mips.org Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/15746/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-04-10MIPS: BPF: Add JIT support for SKF_AD_HATYPE.David Daney
This let's us pass some additional "modprobe test-bpf" tests with JIT enabled. Reuse the code for SKF_AD_IFINDEX, but substitute the offset and size of the "type" field. Signed-off-by: David Daney <david.daney@cavium.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Steven J. Hill <steven.hill@cavium.com> Cc: linux-mips@linux-mips.org Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/15744/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-11treewide: remove redundant #include <linux/kconfig.h>Masahiro Yamada
Kernel source files need not include <linux/kconfig.h> explicitly because the top Makefile forces to include it with: -include $(srctree)/include/linux/kconfig.h This commit removes explicit includes except the following: * arch/s390/include/asm/facilities_src.h * tools/testing/radix-tree/linux/kernel.h These two are used for host programs. Link: http://lkml.kernel.org/r/1473656164-11929-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-06Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds
Pull MIPS updates from Ralf Baechle: "This is the main pull request for MIPS for 4.8. Also includes is a minor SSB cleanup as SSB code traditionally is merged through the MIPS tree: ATH25: - MIPS: Add default configuration for ath25 Boot: - For zboot, copy appended dtb to the end of the kernel - store the appended dtb address in a variable BPF: - Fix off by one error in offset allocation Cobalt code: - Fix typos Core code: - debugfs_create_file returns NULL on error, so don't use IS_ERR for testing for errors. - Fix double locking issue in RM7000 S-cache code. This would only affect RM7000 ARC systems on reboot. - Fix page table corruption on THP permission changes. - Use compat_sys_keyctl for 32 bit userspace on 64 bit kernels. David says, there are no compatibility issues raised by this fix. - Move some signal code around. - Rewrite r4k count/compare clockevent device registration such that min_delta_ticks/max_delta_ticks files are guaranteed to be initialized. - Only register r4k count/compare as clockevent device if we can assume the clock to be constant. - Fix MSA asm warnings in control reg accessors - uasm and tlbex fixes and tweaking. - Print segment physical address when EU=1. - Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFO. - CP: Allow booting by VP other than VP 0 - Cache handling fixes and optimizations for r4k class caches - Add hotplug support for R6 processors - Cleanup hotplug bits in kconfig - traps: return correct si code for accessing nonmapped addresses - Remove cpu_has_safe_index_cacheops Lantiq: - Register IRQ handler for virtual IRQ number - Fix EIU interrupt loading code - Use the real EXIN count - Fix build error. Loongson 3: - Increase HPET_MIN_PROG_DELTA and decrease HPET_MIN_CYCLES Octeon: - Delete built-in DTB pruning code for D-Link DSR-1000N. - Clean up GPIO definitions in dlink_dsr-1000n.dts. - Add more LEDs to the DSR-100n DTS - Fix off by one in octeon_irq_gpio_map() - Typo fixes - Enable SATA by default in cavium_octeon_defconfig - Support readq/writeq() - Remove forced mappings of USB interrupts. - Ensure DMA descriptors are always in the low 4GB - Improve USB reset code for OCTEON II. Pistachio: - Add maintainers entry for pistachio SoC Support - Remove plat_setup_iocoherency Ralink: - Fix pwm UART in spis group pinmux. SSB: - Change bare unsigned to unsigned int to suit coding style Tools: - Fix reloc tool compiler warnings. Other: - Delete use of ARCH_WANT_OPTIONAL_GPIOLIB" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (61 commits) MIPS: mm: Fix definition of R6 cache instruction MIPS: tools: Fix relocs tool compiler warnings MIPS: Cobalt: Fix typo MIPS: Octeon: Fix typo MIPS: Lantiq: Fix build failure MIPS: Use CPHYSADDR to implement mips32 __pa MIPS: Octeon: Dlink_dsr-1000n.dts: add more leds. MIPS: Octeon: Clean up GPIO definitions in dlink_dsr-1000n.dts. MIPS: Octeon: Delete built-in DTB pruning code for D-Link DSR-1000N. MIPS: store the appended dtb address in a variable MIPS: ZBOOT: copy appended dtb to the end of the kernel MIPS: ralink: fix spis group pinmux MIPS: Factor o32 specific code into signal_o32.c MIPS: non-exec stack & heap when non-exec PT_GNU_STACK is present MIPS: Use per-mm page to execute branch delay slot instructions MIPS: Modify error handling MIPS: c-r4k: Use SMP calls for CM indexed cache ops MIPS: c-r4k: Avoid small flush_icache_range SMP calls MIPS: c-r4k: Local flush_icache_range cache op override MIPS: c-r4k: Split r4k_flush_kernel_vmap_range() ...
2016-08-04tree-wide: replace config_enabled() with IS_ENABLED()Masahiro Yamada
The use of config_enabled() against config options is ambiguous. In practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the author might have used it for the meaning of IS_ENABLED(). Using IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc. makes the intention clearer. This commit replaces config_enabled() with IS_ENABLED() where possible. This commit is only touching bool config options. I noticed two cases where config_enabled() is used against a tristate option: - config_enabled(CONFIG_HWMON) [ drivers/net/wireless/ath/ath10k/thermal.c ] - config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE) [ drivers/gpu/drm/gma500/opregion.c ] I did not touch them because they should be converted to IS_BUILTIN() in order to keep the logic, but I was not sure it was the authors' intention. Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Stas Sergeev <stsp@list.ru> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Joshua Kinard <kumba@gentoo.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov <bp@suse.de> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: "Dmitry V. Levin" <ldv@altlinux.org> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Will Drewry <wad@chromium.org> Cc: Nikolay Martynov <mar.kolya@gmail.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: Rafal Milecki <zajec5@gmail.com> Cc: James Cowgill <James.Cowgill@imgtec.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Alex Smith <alex.smith@imgtec.com> Cc: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: Qais Yousef <qais.yousef@imgtec.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Mikko Rapeli <mikko.rapeli@iki.fi> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Brian Norris <computersforpeace@gmail.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: "Luis R. Rodriguez" <mcgrof@do-not-panic.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Kalle Valo <kvalo@qca.qualcomm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Tony Wu <tung7970@gmail.com> Cc: Huaitong Han <huaitong.han@intel.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Juergen Gross <jgross@suse.com> Cc: Jason Cooper <jason@lakedaemon.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Rabin Vincent <rabin@rab.in> Cc: "Maciej W. Rozycki" <macro@imgtec.com> Cc: David Daney <david.daney@cavium.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-21bpf, mips: fix off-by-one in ctx offset allocationDaniel Borkmann
Dan Carpenter reported [1] a static checker warning that ctx->offsets[] may be accessed off by one from build_body(), since it's allocated with fp->len * sizeof(*ctx.offsets) as length. The cBPF arm and ppc code doesn't have this issue as claimed, so only mips seems to be affected and should like most other JITs allocate with fp->len + 1. A few number of JITs (x86, sparc, arm64) handle this differently, where they only require fp->len array elements. [1] http://www.spinics.net/lists/mips/msg64193.html Fixes: c6610de353da ("MIPS: net: Add BPF JIT") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: ast@kernel.org Cc: linux-mips@linux-mips.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13814/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-01-06net: filter: make JITs zero A for SKF_AD_ALU_XOR_XRabin Vincent
The SKF_AD_ALU_XOR_X ancillary is not like the other ancillary data instructions since it XORs A with X while all the others replace A with some loaded value. All the BPF JITs fail to clear A if this is used as the first instruction in a filter. This was found using american fuzzy lop. Add a helper to determine if A needs to be cleared given the first instruction in a filter, and use this in the JITs. Except for ARM, the rest have only been compile-tested. Fixes: 3480593131e0 ("net: filter: get rid of BPF_S_* enum") Signed-off-by: Rabin Vincent <rabin@rab.in> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/usb/asix_common.c net/ipv4/inet_connection_sock.c net/switchdev/switchdev.c In the inet_connection_sock.c case the request socket hashing scheme is completely different in net-next. The other two conflicts were overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-03ebpf: migrate bpf_prog's flags to bitfieldDaniel Borkmann
As we need to add further flags to the bpf_prog structure, lets migrate both bools to a bitfield representation. The size of the base structure (excluding insns) remains unchanged at 40 bytes. Add also tags for the kmemchecker, so that it doesn't throw false positives. Even in case gcc would generate suboptimal code, it's not being accessed in performance critical paths. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-02MIPS: BPF: Fix load delay slots.Ralf Baechle
The entire bpf_jit_asm.S is written in noreorder mode because "we know better" according to a comment. This also prevented the assembler from throwing in the required NOPs for MIPS I processors which have no load-use interlock, thus the load's consumer might end up using the old value of the register from prior to the load. Fixed by putting the assembler in reorder mode for just the affected load instructions. This is not enough for gas to actually try to be clever by looking at the next instruction and inserting a nop only when needed but as the comment said "we know better", so getting gas to unconditionally emit a NOP is just right in this case and prevents adding further ifdefery. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-10-01MIPS: BPF: Do all exports of symbols with FEXPORT().Ralf Baechle
FEXPORT also marks the symbol as code using .type symbol, @function. Without objdump -d will output only a hexdump for code following the affected symbols. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-22MIPS: BPF: Fix build on pre-R2 little endian CPUsAurelien Jarno
The rotr, seh and wsbh instructions have been introduced with the R2 ISA. Thus the current BPF code fails to build on pre-R2 little endian CPUs: CC arch/mips/net/bpf_jit.o AS arch/mips/net/bpf_jit_asm.o /home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S: Assembler messages: /home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:67: Error: opcode not supported on this processor: mips32 (mips32) `wsbh $8,$19' /home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:68: Error: opcode not supported on this processor: mips32 (mips32) `rotr $19,$8,16' /home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:83: Error: opcode not supported on this processor: mips32 (mips32) `wsbh $8,$19' /home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:84: Error: opcode not supported on this processor: mips32 (mips32) `seh $19,$8' /home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:151: Error: opcode not supported on this processor: mips32 (mips32) `wsbh $8,$12' /home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:153: Error: opcode not supported on this processor: mips32 (mips32) `rotr $19,$8,16' /home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:164: Error: opcode not supported on this processor: mips32 (mips32) `wsbh $19,$12' /home/aurel32/linux-4.2/scripts/Makefile.build:294: recipe for target 'arch/mips/net/bpf_jit_asm.o' failed Fix that by providing equivalent code for these CPUs. Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> Reviewed-by: Markos Chandras <markos.chandras@imgtec.com> Cc: stable@vger.kernel.org # v4.2+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/11098/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-22MIPS: BPF: Avoid unreachable code on little endianAurelien Jarno
On little endian, avoid generating the big endian version of the code by using #else in addition to #ifdef #endif. Also fix one alignment issue wrt delay slot. Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> Reviewed-by: Markos Chandras <markos.chandras@imgtec.com> Cc: stable@vger.kernel.org # v4.2+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/11097/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-06-21MIPS: BPF: Introduce BPF ASM helpersMarkos Chandras
This commit introduces BPF ASM helpers for MIPS and MIPS64 kernels. The purpose of this patch is to twofold: 1) We are now able to handle negative offsets instead of either falling back to the interpreter or to simply not do anything and bail out. 2) Optimize reads from the packet header instead of calling the C helpers Because of this patch, we are now able to get rid of quite a bit of code in the JIT generation process by using MIPS optimized assembly code. The new assembly code makes the test_bpf testsuite happy with all 60 test passing successfully compared to the previous implementation where 2 tests were failing. Doing some basic analysis in the results between the old implementation and the new one we can obtain the following summary running current mainline on an ER8 board (+/- 30us delta is ignored to prevent noise from kernel scheduling or IRQ latencies): Summary: 22 tests are faster, 7 are slower and 47 saw no improvement with the most notable improvement being the tcpdump tests. The 7 tests that seem to be a bit slower is because they all follow the slow path (bpf_internal_load_pointer_neg_helper) which is meant to be slow so that's not a problem. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: netdev@vger.kernel.org Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Daniel Borkmann <dborkman@redhat.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: netdev@vger.kernel.org Patchwork: http://patchwork.linux-mips.org/patch/10530/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-06-21MIPS: BPF: Use BPF register names to describe the ABIMarkos Chandras
Use the BPF register names instead of the arch register names to document how the ABI is structured. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: netdev@vger.kernel.org Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Daniel Borkmann <dborkman@redhat.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: linux-kernel@vger.kernel.org Patchwork: http://patchwork.linux-mips.org/patch/10529/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>