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* powerpc/bpf: use unsigned division instruction for 64-bit operationsNaveen N. Rao2019-06-251-1/+1
| | | | | | | | | | | | | | | commit 758f2046ea040773ae8ea7f72dd3bbd8fa984501 upstream. BPF_ALU64 div/mod operations are currently using signed division, unlike BPF_ALU32 operations. Fix the same. DIV64 and MOD64 overflow tests pass with this fix. Fixes: 156d0e290e969c ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF") Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc: bpf: Fix generation of load/store DW instructionsNaveen N. Rao2019-04-031-12/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 86be36f6502c52ddb4b85938145324fd07332da1 upstream. Yauheni Kaliuta pointed out that PTR_TO_STACK store/load verifier test was failing on powerpc64 BE, and rightfully indicated that the PPC_LD() macro is not masking away the last two bits of the offset per the ISA, resulting in the generation of 'lwa' instruction instead of the intended 'ld' instruction. Segher also pointed out that we can't simply mask away the last two bits as that will result in loading/storing from/to a memory location that was not intended. This patch addresses this by using ldx/stdx if the offset is not word-aligned. We load the offset into a temporary register (TMP_REG_2) and use that as the index register in a subsequent ldx/stdx. We fix PPC_LD() macro to mask off the last two bits, but enhance PPC_BPF_LL() and PPC_BPF_STL() to factor in the offset value and generate the proper instruction sequence. We also convert all existing users of PPC_LD() and PPC_STD() to use these macros. All existing uses of these macros have been audited to ensure that TMP_REG_2 can be clobbered. Fixes: 156d0e290e96 ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF") Cc: stable@vger.kernel.org # v4.9+ Reported-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bpf, ppc64: implement jiting of BPF_J{LT, LE, SLT, SLE}Daniel Borkmann2017-08-091-0/+1
| | | | | | | | | | This work implements jiting of BPF_J{LT,LE,SLT,SLE} instructions with BPF_X/BPF_K variants for the ppc64 eBPF JIT. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* powerpc/bpf: Introduce __PPC_SH64()Naveen N. Rao2017-02-101-6/+5
| | | | | | | | | Introduce __PPC_SH64() as a 64-bit variant to encode shift field in some of the shift and rotate instructions operating on double-words. Convert some of the BPF instruction macros to use the same. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/bpf: Implement support for tail callsNaveen N. Rao2016-10-041-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tail calls allow JIT'ed eBPF programs to call into other JIT'ed eBPF programs. This can be achieved either by: (1) retaining the stack setup by the first eBPF program and having all subsequent eBPF programs re-using it, or, (2) by unwinding/tearing down the stack and having each eBPF program deal with its own stack as it sees fit. To ensure that this does not create loops, there is a limit to how many tail calls can be done (currently 32). This requires the JIT'ed code to maintain a count of the number of tail calls done so far. Approach (1) is simple, but requires every eBPF program to have (almost) the same prologue/epilogue, regardless of whether they need it. This is inefficient for small eBPF programs which may not sometimes need a prologue at all. As such, to minimize impact of tail call implementation, we use approach (2) here which needs each eBPF program in the chain to use its own prologue/epilogue. This is not ideal when many tail calls are involved and when all the eBPF programs in the chain have similar prologue/epilogue. However, the impact is restricted to programs that do tail calls. Individual eBPF programs are not affected. We maintain the tail call count in a fixed location on the stack and updated tail call count values are passed in through this. The very first eBPF program in a chain sets this up to 0 (the first 2 instructions). Subsequent tail calls skip the first two eBPF JIT instructions to maintain the count. For programs that don't do tail calls themselves, the first two instructions are NOPs. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/ebpf/jit: Implement JIT compiler for extended BPFNaveen N. Rao2016-06-241-1/+52
| | | | | | | | | | | | | | | | | | | | | | | | | PPC64 eBPF JIT compiler. Enable with: echo 1 > /proc/sys/net/core/bpf_jit_enable or echo 2 > /proc/sys/net/core/bpf_jit_enable ... to see the generated JIT code. This can further be processed with tools/net/bpf_jit_disasm. With CONFIG_TEST_BPF=m and 'modprobe test_bpf': test_bpf: Summary: 305 PASSED, 0 FAILED, [297/297 JIT'ed] ... on both ppc64 BE and LE. The details of the approach are documented through various comments in the code. Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/bpf/jit: Isolate classic BPF JIT specifics into a separate headerNaveen N. Rao2016-06-241-119/+2
| | | | | | | | | | Break out classic BPF JIT specifics into a separate header in preparation for eBPF JIT implementation. Note that ppc32 will still need the classic BPF JIT. Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/bpf/jit: A few cleanupsNaveen N. Rao2016-06-241-6/+7
| | | | | | | | | | | | | | 1. Per the ISA, ADDIS actually uses RT, rather than RS. Though the result is the same, make the usage clear. 2. The multiply instruction used is a 32-bit multiply. Rename PPC_MUL() to PPC_MULW() to make the same clear. 3. PPC_STW[U] take the entire 16-bit immediate value and do not require word-alignment, per the ISA. Change the macros to use IMM_L(). 4. A few white-space cleanups to satisfy checkpatch.pl. Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/bpf/jit: Introduce rotate immediate instructionsNaveen N. Rao2016-06-241-9/+11
| | | | | | | | | | | Since we will be using the rotate immediate instructions for extended BPF JIT, let's introduce macros for the same. And since the shift immediate operations use the rotate immediate instructions, let's redo those macros to use the newly introduced instructions. Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/bpf/jit: Optimize 64-bit Immediate loadsNaveen N. Rao2016-06-241-6/+11
| | | | | | | | | | Similar to the LI32() optimization, if the value can be represented in 32-bits, use LI32(). Also handle loading a few specific forms of immediate values in an optimum manner. Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/bpf/jit: Fix/enhance 32-bit Load Immediate implementationNaveen N. Rao2016-06-241-3/+10
| | | | | | | | | | | | | | | | | | | | | The existing LI32() macro can sometimes result in a sign-extended 32-bit load that does not clear the top 32-bits properly. As an example, loading 0x7fffffff results in the register containing 0xffffffff7fffffff. While this does not impact classic BPF JIT implementation (since that only uses the lower word for all operations), we would like to share this macro between classic BPF JIT and extended BPF JIT, wherein the entire 64-bit value in the register matters. Fix this by first doing a shifted LI followed by ORI. An additional optimization is with loading values between -32768 to -1, where we now only need a single LI. The new implementation now generates the same or less number of instructions. Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* ppc: bpf: Add SKF_AD_CPU for ppc32Denis Kirjanov2015-02-201-0/+17
| | | | | Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* ppc: bpf: update jit to use compatibility macrosDenis Kirjanov2015-02-201-1/+46
| | | | | | | Use helpers from the asm-compat.h to wrap up assembly mnemonics Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* PPC: bpf_jit_comp: add SKF_AD_PKTTYPE instructionDenis Kirjanov2014-11-031-0/+7
| | | | | | | | | | | | | | | | | | | | | Add BPF extension SKF_AD_PKTTYPE to ppc JIT to load skb->pkt_type field. Before: [ 88.262622] test_bpf: #11 LD_IND_NET 86 97 99 PASS [ 88.265740] test_bpf: #12 LD_PKTTYPE 109 107 PASS After: [ 80.605964] test_bpf: #11 LD_IND_NET 44 40 39 PASS [ 80.607370] test_bpf: #12 LD_PKTTYPE 9 9 PASS CC: Alexei Starovoitov<alexei.starovoitov@gmail.com> CC: Michael Ellerman<mpe@ellerman.id.au> Cc: Matt Evans <matt@ozlabs.org> Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org> v2: Added test rusults Signed-off-by: David S. Miller <davem@davemloft.net>
* powerpc/bpf: Support MOD operationVladimir Murzin2013-10-311-0/+1
| | | | | | | | | | | commit b6069a9570 (filter: add MOD operation) added generic support for modulus operation in BPF. This patch brings JIT support for PPC64 Signed-off-by: Vladimir Murzin <murzin.v@gmail.com> Acked-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/bpf: BPF JIT compiler for 64-bit Little EndianPhilippe Bergheaud2013-10-311-0/+10
| | | | | | | | This enables the Berkeley Packet Filter JIT compiler for the PowerPC running in 64bit Little Endian. Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* PPC: net: bpf_jit_comp: add XOR instruction for BPF JITDaniel Borkmann2012-11-171-0/+6
| | | | | | | | | | | This patch is a follow-up for patch "filter: add XOR instruction for use with X/K" that implements BPF PowerPC JIT parts for the BPF XOR operation. Signed-off-by: Daniel Borkmann <daniel.borkmann@tik.ee.ethz.ch> Cc: Matt Evans <matt@ozlabs.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Matt Evans <matt@ozlabs.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* powerpc: Start using ___PPC_RA/B/S/T where necessaryMichael Neuling2012-07-101-53/+53
| | | | | | | | | | | | | | | | Now have ___PPC_RA/B/S/T we can use it in some places. These are places where we can't use the existing defines which will soon enforce R0-R31 usage. The macros being changed here are being used in inline asm, which can't convert to enforce the R0-R31 usage. bpf_jit uses a mix of both generated and non-generated with the same code, so just convert all these to use the ___PPC_R versions which won't enforce R usage later. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* bpf jit: Let the powerpc jit handle negative offsetsJan Seiffert2012-04-301-1/+7
| | | | | | | | | | | | | | | | | | | | | Now the helper function from filter.c for negative offsets is exported, it can be used it in the jit to handle negative offsets. First modify the asm load helper functions to handle: - know positive offsets - know negative offsets - any offset then the compiler can be modified to explicitly use these helper when appropriate. This fixes the case of a negative X register and allows to lift the restriction that bpf programs with negative offsets can't be jited. Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Jan Seiffert <kaffeemonster@googlemail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: filter: BPF 'JIT' compiler for PPC64Matt Evans2011-07-211-0/+227
An implementation of a code generator for BPF programs to speed up packet filtering on PPC64, inspired by Eric Dumazet's x86-64 version. Filter code is generated as an ABI-compliant function in module_alloc()'d mem with stackframe & prologue/epilogue generated if required (simple filters don't need anything more than an li/blr). The filter's local variables, M[], live in registers. Supports all BPF opcodes, although "complicated" loads from negative packet offsets (e.g. SKF_LL_OFF) are not yet supported. There are a couple of further optimisations left for future work; many-pass assembly with branch-reach reduction and a register allocator to push M[] variables into volatile registers would improve the code quality further. This currently supports big-endian 64-bit PowerPC only (but is fairly simple to port to PPC32 or LE!). Enabled in the same way as x86-64: echo 1 > /proc/sys/net/core/bpf_jit_enable Or, enabled with extra debug output: echo 2 > /proc/sys/net/core/bpf_jit_enable Signed-off-by: Matt Evans <matt@ozlabs.org> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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