From d218e7fedc74d67837d2134120917f4ac877454c Mon Sep 17 00:00:00 2001 From: "Jose E. Marchesi" Date: Sat, 15 Jul 2023 00:50:14 +0200 Subject: DesCGENization of the BPF binutils port CGEN is cool, but the BPF architecture is simply too bizarre for it. The weird way of BPF to handle endianness in instruction encoding, the weird C-like alternative assembly syntax, the weird abuse of multi-byte (or infra-byte) instruction fields as opcodes, the unusual presence of opcodes beyond the first 32-bits of some instructions, are all examples of what makes it a PITA to continue using CGEN for this port. The bpf.cpu file is becoming so complex and so nested with p-macros that it is very difficult to read, and quite challenging to update. Also, every time we are forced to change something in CGEN to accommodate BPF requirements (which is often) we have to do extensive testing to make sure we do not break any other target using CGEN. This is getting un-maintenable. So I have decided to bite the bullet and revamp/rewrite the port so it no longer uses CGEN. Overall, this involved: * To remove the cpu/bpf.{cpu,opc} descriptions. * To remove the CGEN generated files. * To replace the CGEN generated opcodes table with a new hand-written opcodes table for BPF. * To replace the CGEN generated disassembler wih a new disassembler that uses the new opcodes. * To replace the CGEN generated assembler with a new assembler that uses the new opcodes. * To replace the CGEN generated simulator with a new simulator that uses the new opcodes. [This is pushed in GDB in another patch.] * To adapt the build systems to the new situation. Additionally, this patch introduces some extensions and improvements: * A new BPF relocation BPF_RELOC_BPF_DISP16 plus corresponding ELF relocation R_BPF_GNU_64_16 are added to the BPF BFD port. These relocations are used for section-relative 16-bit offsets used in load/store instructions. * The disassembler now has support for the "pseudo-c" assembly syntax of BPF. What dialect to use when disassembling is controlled by a command line option. * The disassembler now has support for dumping instruction immediates in either octal, hexadecimal or decimal. The used output base is controlled by a new command-line option. * The GAS BPF test suite has been re-structured and expanded in order to test the disassembler pseudoc syntax support. Minor bugs have been also fixed there. The assembler generic tests that were disabled for bpf-*-* targets due to the previous implementation of pseudoc syntax are now re-enabled. Additional tests have been added to test the new features of the assembler. .dump files are no longer used. * The linker BPF test suite has been adapted to the command line options used by the new disassembler. The result is very satisfactory. This patchs adds 3448 lines of code and removes 10542 lines of code. Tested in: * Target bpf-unknown-none with 64-bit little-endian host and 32-bit little-endian host. * Target x86-64-linux-gnu with --enable-targets=all Note that I have not tested in a big-endian host yet. I will do so once this lands upstream so I can use the GCC compiler farm. I have not included ChangeLog entries in this patch: these would be massive and not very useful, considering this is pretty much a rewrite of the port. I beg the indulgence of the global maintainers. --- cpu/bpf.cpu | 855 ------------------------------------------------------------ cpu/bpf.opc | 191 -------------- 2 files changed, 1046 deletions(-) delete mode 100644 cpu/bpf.cpu delete mode 100644 cpu/bpf.opc (limited to 'cpu') diff --git a/cpu/bpf.cpu b/cpu/bpf.cpu deleted file mode 100644 index 2ae74fc..0000000 --- a/cpu/bpf.cpu +++ /dev/null @@ -1,855 +0,0 @@ -;; Linux BPF CPU description -*- Scheme -*- -;; Copyright (C) 2019 Free Software Foundation, Inc. -;; -;; Contributed by Oracle Inc. -;; -;; This file is part of the GNU Binutils and of GDB. -;; -;; 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; either version 3 of the -;; License, or (at your option) any later version. -;; -;; This program is distributed in the hope that it will be useful, but -;; WITHOUT ANY WARRANTY; without even the implied warranty of -;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -;; General Public License for more details. -;; -;; You should have received a copy of the GNU General Public License -;; along with this program; if not, write to the Free Software -;; Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA -;; 02110-1301, USA. - -;; This file contains a CGEN CPU description for the Linux kernel eBPF -;; instruction set. eBPF is documented in the linux kernel source -;; tree. See linux/Documentation/networking/filter.txt, and also the -;; sources in the networking subsystem, notably -;; linux/net/core/filter.c. - -(include "simplify.inc") - -(define-arch - (name bpf) - (comment "Linux kernel BPF") - (insn-lsb0? #t) - ;; XXX explain the default-alignment setting is for the simulator. - ;; It is confusing that the simulator follows the emulated memory - ;; access conventions for fetching instructions by pieces... - (default-alignment unaligned) - (machs bpf xbpf) - (isas ebpfle ebpfbe xbpfle xbpfbe)) - -;;;; The ISAs - -;; Logically, eBPF comforms a single instruction set featuring two -;; kind of instructions: 64-bit instructions and 128-bit instructions. -;; -;; The 64-bit instructions have the form: -;; -;; code:8 regs:8 offset:16 imm:32 -;; -;; Whereas the 128-bit instructions (at the moment there is only one -;; of such instructions, lddw) have the form: -;; -;; code:8 regs:8 offset:16 imm:32 unused:32 imm:32 -;; -;; In both formats `regs' is itself composed by two fields: -;; -;; dst:4 src:4 -;; -;; The ISA is supposed to be orthogonal to endianness: the endianness -;; of the instruction fields follow the endianness of the host running -;; the eBPF program, and that's all. However, this is not entirely -;; true. The definition of an eBPF code in the Linux kernel is: -;; -;; struct bpf_insn { -;; __u8 code; /* opcode */ -;; __u8 dst_reg:4; /* dest register */ -;; __u8 src_reg:4; /* source register */ -;; __s16 off; /* signed offset */ -;; __s32 imm; /* signed immediate constant */ -;; }; -;; -;; Since the ordering of fields in C bitmaps is defined by the -;; implementation, the impact of endianness in the encoding of eBPF -;; instructions is effectively defined by GCC. In particular, GCC -;; places dst_reg before src_reg in little-endian code, and the other -;; way around in big-endian code. -;; -;; So, in reality, eBPF comprises two instruction sets: one for -;; little-endian with instructions like: -;; -;; code:8 src:4 dst:4 offset:16 imm:32 [unused:32 imm:32] -;; -;; and another for big-endian with instructions like: -;; -;; code:8 dst:4 src:4 offset:16 imm:32 [unused:32 imm:32] -;; -;; where `offset' and the immediate fields are encoded in -;; little-endian and big-endian byte-order, respectively. - -(define-pmacro (define-bpf-isa x-endian) - (define-isa - (name (.sym ebpf x-endian)) - (comment "The eBPF instruction set") - ;; Default length to record in ifields. This is used in - ;; calculations involving bit numbers. - (default-insn-word-bitsize 64) - ;; Length of an unknown instruction. Used by disassembly and by the - ;; simulator's invalid insn handler. - (default-insn-bitsize 64) - ;; Number of bits of insn that can be initially fetched. This is - ;; the size of the smallest insn. - (base-insn-bitsize 64))) - -(define-bpf-isa le) -(define-bpf-isa be) - -(define-pmacro (define-xbpf-isa x-endian) - (define-isa - (name (.sym xbpf x-endian)) - (comment "The xBPF instruction set") - (default-insn-word-bitsize 64) - (default-insn-bitsize 64) - (base-insn-bitsize 64))) - -(define-xbpf-isa le) -(define-xbpf-isa be) - -(define-pmacro all-isas () (ISA ebpfle,ebpfbe,xbpfle,xbpfbe)) -(define-pmacro xbpf-isas () (ISA xbpfle,xbpfbe)) - -(define-pmacro (endian-isas x-endian) - ((ISA (.sym ebpf x-endian) (.sym xbpf x-endian)))) - -;;;; Hardware Hierarchy - -;; -;; bpf architecture -;; | -;; bpfbf cpu-family -;; / \ -;; bpf xbpf machine -;; | | -;; bpf-def xbpf-def model - -(define-cpu - (name bpfbf) - (comment "Linux kernel eBPF virtual CPU") - (insn-endian big) - (word-bitsize 64)) - -(define-mach - (name bpf) - (comment "Linux eBPF") - (cpu bpfbf) - (isas ebpfle ebpfbe)) - -(define-model - (name bpf-def) - (comment "Linux eBPF default model") - (mach bpf) - (unit u-exec "execution unit" () - 1 ; issue - 1 ; done - () ; state - () ; inputs - () ; outputs - () ; profile action (default) - )) - -(define-mach - (name xbpf) - (comment "Experimental BPF") - (cpu bpfbf) - (isas ebpfle ebpfbe xbpfle xbpfbe)) - -(define-model - (name xbpf-def) - (comment "xBPF default model") - (mach xbpf) - (unit u-exec "execution unit" () - 1 ; issue - 1 ; done - () ; state - () ; inputs - () ; outputs - () ; profile action (default) - )) - -;;;; Hardware Elements - -;; eBPF programs can access 10 general-purpose registers which are -;; 64-bit. - -(define-hardware - (name h-gpr) - (comment "General Purpose Registers") - (attrs all-isas (MACH bpf xbpf)) - (type register DI (16)) - (indices keyword "%" - ;; XXX the frame pointer fp is read-only, so it should - ;; go in a different hardware. - (;; ABI names. Take priority when disassembling. - (r0 0) (r1 1) (r2 2) (r3 3) (r4 4) (r5 5) (r6 6) - (r7 7) (r8 8) (r9 9) (fp 10) - ;; Additional names recognized when assembling. - (r0 0) (r6 6) (r10 10)))) - -;; The program counter. CGEN requires it, even if it is not visible -;; to eBPF programs. - -(define-hardware - (name h-pc) - (comment "program counter") - (attrs PC PROFILE all-isas) - (type pc UDI) - (get () (raw-reg h-pc)) - (set (newval) (set (raw-reg h-pc) newval))) - -;; A 64-bit h-sint to be used by the imm64 operand below. XXX this -;; shouldn't be needed, as h-sint is supposed to be able to hold -;; 64-bit values. However, in practice CGEN limits h-sint to 32 bits -;; in 32-bit hosts. To be fixed in CGEN. - -(dnh h-sint64 "signed 64-bit integer" (all-isas) (immediate DI) - () () ()) - -;;;; The Instruction Sets - -;;; Fields and Opcodes - -;; Convenience macro to shorten the definition of the fields below. -(define-pmacro (dwf x-name x-comment x-attrs - x-word-offset x-word-length x-start x-length - x-mode) - "Define a field including its containing word." - (define-ifield - (name x-name) - (comment x-comment) - (.splice attrs (.unsplice x-attrs)) - (word-offset x-word-offset) - (word-length x-word-length) - (start x-start) - (length x-length) - (mode x-mode))) - -;; For arithmetic and jump instructions the 8-bit code field is -;; subdivided in: -;; -;; op-code:4 op-src:1 op-class:3 - -(dwf f-op-code "eBPF opcode code" (all-isas) 0 8 7 4 UINT) -(dwf f-op-src "eBPF opcode source" (all-isas) 0 8 3 1 UINT) -(dwf f-op-class "eBPF opcode instruction class" (all-isas) 0 8 2 3 UINT) - -(define-normal-insn-enum insn-op-code-alu "eBPF instruction codes" - (all-isas) OP_CODE_ f-op-code - (;; Codes for OP_CLASS_ALU and OP_CLASS_ALU64 - (ADD #x0) (SUB #x1) (MUL #x2) (DIV #x3) (OR #x4) (AND #x5) - (LSH #x6) (RSH #x7) (NEG #x8) (MOD #x9) (XOR #xa) (MOV #xb) - (ARSH #xc) (END #xd) - ;; xBPF-only: signed div, signed mod - (SDIV #xe) (SMOD #xf) - ;; Codes for OP_CLASS_JMP - (JA #x0) (JEQ #x1) (JGT #x2) (JGE #x3) (JSET #x4) - (JNE #x5) (JSGT #x6) (JSGE #x7) (CALL #x8) (EXIT #x9) - (JLT #xa) (JLE #xb) (JSLT #xc) (JSLE #xd))) - -(define-normal-insn-enum insn-op-src "eBPF instruction source" - (all-isas) OP_SRC_ f-op-src - ;; X => use `src' as source operand. - ;; K => use `imm32' as source operand. - ((K #b0) (X #b1))) - -(define-normal-insn-enum insn-op-class "eBPF instruction class" - (all-isas) OP_CLASS_ f-op-class - ((LD #b000) (LDX #b001) (ST #b010) (STX #b011) - (ALU #b100) (JMP #b101) (JMP32 #b110) (ALU64 #b111))) - -;; For load/store instructions, the 8-bit code field is subdivided in: -;; -;; op-mode:3 op-size:2 op-class:3 - -(dwf f-op-mode "eBPF opcode mode" (all-isas) 0 8 7 3 UINT) -(dwf f-op-size "eBPF opcode size" (all-isas) 0 8 4 2 UINT) - -(define-normal-insn-enum insn-op-mode "eBPF load/store instruction modes" - (all-isas) OP_MODE_ f-op-mode - ((IMM #b000) (ABS #b001) (IND #b010) (MEM #b011) - ;; #b100 and #b101 are used in classic BPF only, reserved in eBPF. - (XADD #b110))) - -(define-normal-insn-enum insn-op-size "eBPF load/store instruction sizes" - (all-isas) OP_SIZE_ f-op-size - ((W #b00) ;; Word: 4 byte - (H #b01) ;; Half-word: 2 byte - (B #b10) ;; Byte: 1 byte - (DW #b11))) ;; Double-word: 8 byte - -;; The fields for the source and destination registers are a bit -;; tricky. Due to the bizarre nibble swap between little-endian and -;; big-endian ISAs we need to keep different variants of the fields. -;; -;; Note that f-regs is used in the format spec of instructions that do -;; NOT use registers, where endianness is irrelevant i.e. f-regs is a -;; constant 0 opcode. - -(dwf f-dstle "eBPF dst register field" ((ISA ebpfle xbpfle)) 8 8 3 4 UINT) -(dwf f-srcle "eBPF source register field" ((ISA ebpfle xbpfle)) 8 8 7 4 UINT) - -(dwf f-dstbe "eBPF dst register field" ((ISA ebpfbe xbpfbe)) 8 8 7 4 UINT) -(dwf f-srcbe "eBPF source register field" ((ISA ebpfbe xbpfbe)) 8 8 3 4 UINT) - -(dwf f-regs "eBPF registers field" (all-isas) 8 8 7 8 UINT) - -;; Finally, the fields for the immediates. -;; -;; The 16-bit offsets and 32-bit immediates do not present any special -;; difficulty: we put them in their own instruction word so the -;; byte-endianness will be properly applied. - -(dwf f-offset16 "eBPF offset field" (all-isas) 16 16 15 16 HI) -(dwf f-imm32 "eBPF 32-bit immediate field" (all-isas) 32 32 31 32 INT) - -;; For the disjoint 64-bit signed immediate, however, we need to use a -;; multi-ifield. - -(dwf f-imm64-a "eBPF 64-bit immediate a" (all-isas) 32 32 31 32 UINT) -(dwf f-imm64-b "eBPF 64-bit immediate b" (all-isas) 64 32 31 32 UINT) -(dwf f-imm64-c "eBPF 64-bit immediate c" (all-isas) 96 32 31 32 UINT) - -(define-multi-ifield - (name f-imm64) - (comment "eBPF 64-bit immediate field") - (attrs all-isas) - (mode DI) - (subfields f-imm64-a f-imm64-b f-imm64-c) - (insert (sequence () - (set (ifield f-imm64-b) (const 0)) - (set (ifield f-imm64-c) (srl (ifield f-imm64) (const 32))) - (set (ifield f-imm64-a) (and (ifield f-imm64) (const #xffffffff))))) - (extract (sequence () - (set (ifield f-imm64) - (or (sll UDI (zext UDI (ifield f-imm64-c)) (const 32)) - (zext UDI (ifield f-imm64-a))))))) - -;;; Operands - -;; A couple of source and destination register operands are defined -;; for each ISA: ebpfle and ebpfbe. - -(dno dstle "destination register" ((ISA ebpfle xbpfle)) h-gpr f-dstle) -(dno srcle "source register" ((ISA ebpfle xbpfle)) h-gpr f-srcle) - -(dno dstbe "destination register" ((ISA ebpfbe xbpfbe)) h-gpr f-dstbe) -(dno srcbe "source register" ((ISA ebpfbe xbpfbe)) h-gpr f-srcbe) - -;; Jump instructions have a 16-bit PC-relative address. -;; CALL instructions have a 32-bit PC-relative address. - -(dno disp16 "16-bit PC-relative address" (all-isas PCREL-ADDR) h-sint - f-offset16) -(dno disp32 "32-bit PC-relative address" (all-isas PCREL-ADDR) h-sint - f-imm32) - -;; Immediate operands in eBPF are signed, and we want the disassembler -;; to print negative values in a sane way. Therefore we use the macro -;; below to register a printer, which is itself defined as a C -;; function in bpf.opc. - -;; define-normal-signed-immediate-operand -(define-pmacro (dnsio x-name x-comment x-attrs x-type x-index) - (define-operand - (name x-name) - (comment x-comment) - (.splice attrs (.unsplice x-attrs)) - (type x-type) - (index x-index) - (handlers (print "immediate")))) - -(dnsio imm32 "32-bit immediate" (all-isas) h-sint f-imm32) -(dnsio offset16 "16-bit offset" (all-isas) h-sint f-offset16) - -;; The 64-bit immediate cannot use the default -;; cgen_parse_signed_integer, because it assumes operands are at much -;; 32-bit wide. Use our own. - -(define-operand - (name imm64) - (comment "64-bit immediate") - (attrs all-isas) - (type h-sint64) - (index f-imm64) - (handlers (parse "imm64") (print "immediate"))) - -;; The endle/endbe instructions take an operand to specify the word -;; width in endianness conversions. We use both a parser and printer, -;; which are defined as C functions in bpf.opc. - -(define-operand - (name endsize) - (comment "endianness size immediate: 16, 32 or 64") - (attrs all-isas) - (type h-uint) - (index f-imm32) - (handlers (parse "endsize") (print "endsize"))) - -;;; ALU instructions - -;; For each opcode in insn-op-code-alu representing and integer -;; arithmetic instruction (ADD, SUB, etc) we define a bunch of -;; instruction variants: -;; -;; ADD[32]{i,r}le for the little-endian ISA -;; ADD[32]{i,r}be for the big-endian ISA -;; -;; The `i' variants perform `dst OP imm32 -> dst' operations. -;; The `r' variants perform `dst OP src -> dst' operations. -;; -;; The variants with 32 in their name are of ALU class. Otherwise -;; they are ALU64 class. - -(define-pmacro (define-alu-insn-un x-basename x-suffix x-op-class x-op-code - x-endian x-mode x-semop) - (dni (.sym x-basename x-suffix x-endian) - (.str x-basename x-suffix) - (endian-isas x-endian) - (.str x-basename x-suffix " $dst" x-endian) - (+ (f-imm32 0) (f-offset16 0) ((.sym f-src x-endian) 0) (.sym dst x-endian) - x-op-class OP_SRC_K x-op-code) - (set x-mode (.sym dst x-endian) (x-semop x-mode (.sym dst x-endian))) - ())) - -(define-pmacro (define-alu-insn-bin x-basename x-suffix x-op-class x-op-code - x-endian x-mode x-semop x-isas) - (begin - ;; dst = dst OP immediate - (dni (.sym x-basename x-suffix "i" x-endian) - (.str x-basename x-suffix " immediate") - (.splice (.unsplice x-isas)) - (.str x-basename x-suffix " $dst" x-endian ",$imm32") - (+ imm32 (f-offset16 0) ((.sym f-src x-endian) 0) (.sym dst x-endian) - x-op-class OP_SRC_K x-op-code) - (set x-mode (.sym dst x-endian) (x-semop x-mode (.sym dst x-endian) imm32)) - ()) - ;; dst = dst OP src - (dni (.sym x-basename x-suffix "r" x-endian) - (.str x-basename x-suffix " register") - (.splice (.unsplice x-isas)) - (.str x-basename x-suffix " $dst" x-endian ",$src" x-endian) - (+ (f-imm32 0) (f-offset16 0) (.sym src x-endian) (.sym dst x-endian) - x-op-class OP_SRC_X x-op-code) - (set x-mode (.sym dst x-endian) - (x-semop x-mode (.sym dst x-endian) (.sym src x-endian))) - ()))) - -(define-pmacro (define-alu-insn-mov x-basename x-suffix x-op-class x-op-code - x-endian x-mode) - (begin - (dni (.sym mov x-suffix "i" x-endian) - (.str mov x-suffix " immediate") - (endian-isas x-endian) - (.str x-basename x-suffix " $dst" x-endian ",$imm32") - (+ imm32 (f-offset16 0) ((.sym f-src x-endian) 0) (.sym dst x-endian) - x-op-class OP_SRC_K x-op-code) - (set x-mode (.sym dst x-endian) imm32) - ()) - (dni (.sym mov x-suffix "r" x-endian) - (.str mov x-suffix " register") - (endian-isas x-endian) - (.str x-basename x-suffix " $dst" x-endian ",$src" x-endian) - (+ (f-imm32 0) (f-offset16 0) (.sym src x-endian) (.sym dst x-endian) - x-op-class OP_SRC_X x-op-code) - (set x-mode (.sym dst x-endian) (.sym src x-endian)) - ()))) - - -;; Unary ALU instructions (neg) -(define-pmacro (daiu x-basename x-op-code x-endian x-semop) - (begin - (define-alu-insn-un x-basename "" OP_CLASS_ALU64 x-op-code x-endian DI x-semop) - (define-alu-insn-un x-basename "32" OP_CLASS_ALU x-op-code x-endian USI x-semop))) - -;; Binary ALU instructions (all the others) -;; For ALU32: DST = (u32) DST OP (u32) SRC is correct semantics -(define-pmacro (daib x-basename x-op-code x-endian x-semop x-isas) - (begin - (define-alu-insn-bin x-basename "" OP_CLASS_ALU64 x-op-code x-endian DI x-semop x-isas) - (define-alu-insn-bin x-basename "32" OP_CLASS_ALU x-op-code x-endian USI x-semop x-isas))) - -;; Move ALU instructions (mov) -(define-pmacro (daim x-basename x-op-code x-endian) - (begin - (define-alu-insn-mov x-basename "" OP_CLASS_ALU64 x-op-code x-endian DI) - (define-alu-insn-mov x-basename "32" OP_CLASS_ALU x-op-code x-endian USI))) - -(define-pmacro (define-alu-instructions x-endian) - (begin - (daib add OP_CODE_ADD x-endian add (endian-isas x-endian)) - (daib sub OP_CODE_SUB x-endian sub (endian-isas x-endian)) - (daib mul OP_CODE_MUL x-endian mul (endian-isas x-endian)) - (daib div OP_CODE_DIV x-endian udiv (endian-isas x-endian)) - (daib or OP_CODE_OR x-endian or (endian-isas x-endian)) - (daib and OP_CODE_AND x-endian and (endian-isas x-endian)) - (daib lsh OP_CODE_LSH x-endian sll (endian-isas x-endian)) - (daib rsh OP_CODE_RSH x-endian srl (endian-isas x-endian)) - (daib mod OP_CODE_MOD x-endian umod (endian-isas x-endian)) - (daib xor OP_CODE_XOR x-endian xor (endian-isas x-endian)) - (daib arsh OP_CODE_ARSH x-endian sra (endian-isas x-endian)) - (daib sdiv OP_CODE_SDIV x-endian div ((ISA (.sym xbpf x-endian)))) - (daib smod OP_CODE_SMOD x-endian mod ((ISA (.sym xbpf x-endian)))) - (daiu neg OP_CODE_NEG x-endian neg) - (daim mov OP_CODE_MOV x-endian))) - -(define-alu-instructions le) -(define-alu-instructions be) - -;;; Endianness conversion instructions - -;; The endianness conversion instructions come in several variants: -;; -;; END{le,be}le for the little-endian ISA -;; END{le,be}be for the big-endian ISA -;; -;; Please do not be confused by the repeated `be' and `le' here. Each -;; ISA has both endle and endbe instructions. It is the disposition -;; of the source and destination register fields that change between -;; ISAs, not the semantics of the instructions themselves (see section -;; "The ISAs" above in this very file.) - -(define-pmacro (define-endian-insn x-suffix x-op-src x-endian) - (dni (.sym "end" x-suffix x-endian) - (.str "end" x-suffix " register") - (endian-isas x-endian) - (.str "end" x-suffix " $dst" x-endian ",$endsize") - (+ (f-offset16 0) ((.sym f-src x-endian) 0) (.sym dst x-endian) endsize - OP_CLASS_ALU x-op-src OP_CODE_END) - (set (.sym dst x-endian) - (c-call DI (.str "bpfbf_end" x-suffix) (.sym dst x-endian) endsize)) - ())) - -(define-endian-insn "le" OP_SRC_K le) -(define-endian-insn "be" OP_SRC_X le) -(define-endian-insn "le" OP_SRC_K be) -(define-endian-insn "be" OP_SRC_X be) - -;;; Load/Store instructions - -;; The lddw instruction takes a 64-bit immediate as an operand. Since -;; this instruction also takes a `dst' operand, we need to define a -;; variant for each ISA: -;; -;; LDDWle for the little-endian ISA -;; LDDWbe for the big-endian ISA - -(define-pmacro (define-lddw x-endian) - (dni (.sym lddw x-endian) - (.str "lddw" x-endian) - (endian-isas x-endian) - (.str "lddw $dst" x-endian ",$imm64") - (+ imm64 (f-offset16 0) ((.sym f-src x-endian) 0) - (.sym dst x-endian) - OP_CLASS_LD OP_SIZE_DW OP_MODE_IMM) - (set DI (.sym dst x-endian) imm64) - ())) - -(define-lddw le) -(define-lddw be) - -;; The absolute load instructions are non-generic loads designed to be -;; used in socket filters. They come in several variants: -;; -;; LDABS{w,h,b,dw} - -(define-pmacro (dlabs x-suffix x-size x-smode) - (dni (.sym "ldabs" x-suffix) - (.str "ldabs" x-suffix) - (all-isas) - (.str "ldabs" x-suffix " $imm32") - (+ imm32 (f-offset16 0) (f-regs 0) - OP_CLASS_LD OP_MODE_ABS (.sym OP_SIZE_ x-size)) - (set x-smode - (reg x-smode h-gpr 0) - (mem x-smode - (add DI - (mem DI - (add DI - (reg DI h-gpr 6) ;; Pointer to struct sk_buff - (c-call "bpfbf_skb_data_offset"))) - imm32))) - ;; XXX this clobbers R1-R5 - ())) - -(dlabs "w" W SI) -(dlabs "h" H HI) -(dlabs "b" B QI) -(dlabs "dw" DW DI) - -;; The indirect load instructions are non-generic loads designed to be -;; used in socket filters. They come in several variants: -;; -;; LDIND{w,h,b,dw}le for the little-endian ISA -;; LDIND[w,h,b,dw}be for the big-endian ISA - -(define-pmacro (dlind x-suffix x-size x-endian x-smode) - (dni (.sym "ldind" x-suffix x-endian) - (.str "ldind" x-suffix) - (endian-isas x-endian) - (.str "ldind" x-suffix " $src" x-endian ",$imm32") - (+ imm32 (f-offset16 0) ((.sym f-dst x-endian) 0) (.sym src x-endian) - OP_CLASS_LD OP_MODE_IND (.sym OP_SIZE_ x-size)) - (set x-smode - (reg x-smode h-gpr 0) - (mem x-smode - (add DI - (mem DI - (add DI - (reg DI h-gpr 6) ;; Pointer to struct sk_buff - (c-call "bpfbf_skb_data_offset"))) - (add DI - (.sym src x-endian) - imm32)))) - ;; XXX this clobbers R1-R5 - ())) - -(define-pmacro (define-ldind x-endian) - (begin - (dlind "w" W x-endian SI) - (dlind "h" H x-endian HI) - (dlind "b" B x-endian QI) - (dlind "dw" DW x-endian DI))) - -(define-ldind le) -(define-ldind be) - -;; Generic load and store instructions are provided for several word -;; sizes. They come in several variants: -;; -;; LDX{b,h,w,dw}le, STX{b,h,w,dw}le for the little-endian ISA -;; -;; LDX{b,h,w,dw}be, STX{b,h,w,dw}be for the big-endian ISA -;; -;; Loads operate on [$SRC+-OFFSET] -> $DST -;; Stores operate on $SRC -> [$DST+-OFFSET] - -(define-pmacro (dxli x-basename x-suffix x-size x-endian x-mode) - (dni (.sym x-basename x-suffix x-endian) - (.str x-basename x-suffix) - (endian-isas x-endian) - (.str x-basename x-suffix " $dst" x-endian ",[$src" x-endian "+$offset16]") - (+ (f-imm32 0) offset16 (.sym src x-endian) (.sym dst x-endian) - OP_CLASS_LDX (.sym OP_SIZE_ x-size) OP_MODE_MEM) - (set x-mode - (.sym dst x-endian) - (mem x-mode (add DI (.sym src x-endian) offset16))) - ())) - -(define-pmacro (dxsi x-basename x-suffix x-size x-endian x-mode) - (dni (.sym x-basename x-suffix x-endian) - (.str x-basename x-suffix) - (endian-isas x-endian) - (.str x-basename x-suffix " [$dst" x-endian "+$offset16],$src" x-endian) - (+ (f-imm32 0) offset16 (.sym src x-endian) (.sym dst x-endian) - OP_CLASS_STX (.sym OP_SIZE_ x-size) OP_MODE_MEM) - (set x-mode - (mem x-mode (add DI (.sym dst x-endian) offset16)) - (.sym src x-endian)) ;; XXX address is section-relative - ())) - -(define-pmacro (define-ldstx-insns x-endian) - (begin - (dxli "ldx" "w" W x-endian SI) - (dxli "ldx" "h" H x-endian HI) - (dxli "ldx" "b" B x-endian QI) - (dxli "ldx" "dw" DW x-endian DI) - - (dxsi "stx" "w" W x-endian SI) - (dxsi "stx" "h" H x-endian HI) - (dxsi "stx" "b" B x-endian QI) - (dxsi "stx" "dw" DW x-endian DI))) - -(define-ldstx-insns le) -(define-ldstx-insns be) - -;; Generic store instructions of the form IMM32 -> [$DST+OFFSET] are -;; provided in several variants: -;; -;; ST{b,h,w,dw}le for the little-endian ISA -;; ST{b,h,w,dw}be for the big-endian ISA - -(define-pmacro (dsti x-suffix x-size x-endian x-mode) - (dni (.sym "st" x-suffix x-endian) - (.str "st" x-suffix) - (endian-isas x-endian) - (.str "st" x-suffix " [$dst" x-endian "+$offset16],$imm32") - (+ imm32 offset16 ((.sym f-src x-endian) 0) (.sym dst x-endian) - OP_CLASS_ST (.sym OP_SIZE_ x-size) OP_MODE_MEM) - (set x-mode - (mem x-mode (add DI (.sym dst x-endian) offset16)) - imm32) ;; XXX address is section-relative - ())) - -(define-pmacro (define-st-insns x-endian) - (begin - (dsti "b" B x-endian QI) - (dsti "h" H x-endian HI) - (dsti "w" W x-endian SI) - (dsti "dw" DW x-endian DI))) - -(define-st-insns le) -(define-st-insns be) - -;;; Jump instructions - -;; Compare-and-jump instructions, on the other hand, make use of -;; registers. Therefore, we need to define several variants in both -;; ISAs: -;; -;; J{eq,gt,ge,lt,le,set,ne,sgt,sge,slt,sle}[32]{i,r}le for the -;; little-endian ISA. -;; J{eq,gt,ge,lt,le,set,ne.sgt,sge,slt,sle}[32]{i,r}be for the -;; big-endian ISA. - -(define-pmacro (define-cond-jump-insn x-cond x-suffix x-op-class x-op-code x-endian x-mode x-semop) - (begin - (dni (.sym j x-cond x-suffix i x-endian) - (.str j x-cond x-suffix " i") - (endian-isas x-endian) - (.str "j" x-cond x-suffix " $dst" x-endian ",$imm32,$disp16") - (+ imm32 disp16 ((.sym f-src x-endian) 0) (.sym dst x-endian) - x-op-class OP_SRC_K (.sym OP_CODE_ x-op-code)) - (if VOID (x-semop x-mode (.sym dst x-endian) imm32) - (set DI - (reg DI h-pc) (add DI (reg DI h-pc) - (mul DI (add HI disp16 1) 8)))) - ()) - (dni (.sym j x-cond x-suffix r x-endian) - (.str j x-cond x-suffix " r") - (endian-isas x-endian) - (.str "j" x-cond x-suffix " $dst" x-endian ",$src" x-endian ",$disp16") - (+ (f-imm32 0) disp16 (.sym src x-endian) (.sym dst x-endian) - x-op-class OP_SRC_X (.sym OP_CODE_ x-op-code)) - (if VOID (x-semop x-mode (.sym dst x-endian) (.sym src x-endian)) - (set DI - (reg DI h-pc) (add DI (reg DI h-pc) - (mul DI (add HI disp16 1) 8)))) - ()))) - -(define-pmacro (dcji x-cond x-op-code x-endian x-semop) - (begin - (define-cond-jump-insn x-cond "" OP_CLASS_JMP x-op-code x-endian DI x-semop) - (define-cond-jump-insn x-cond "32" OP_CLASS_JMP32 x-op-code x-endian SI x-semop ))) - -(define-pmacro (define-condjump-insns x-endian) - (begin - (dcji "eq" JEQ x-endian eq) - (dcji "gt" JGT x-endian gtu) - (dcji "ge" JGE x-endian geu) - (dcji "lt" JLT x-endian ltu) - (dcji "le" JLE x-endian leu) - (dcji "set" JSET x-endian and) - (dcji "ne" JNE x-endian ne) - (dcji "sgt" JSGT x-endian gt) - (dcji "sge" JSGE x-endian ge) - (dcji "slt" JSLT x-endian lt) - (dcji "sle" JSLE x-endian le))) - -(define-condjump-insns le) -(define-condjump-insns be) - -;; The `call' instruction doesn't make use of registers, but the -;; semantic routine should have access to the src register in order to -;; properly interpret the meaning of disp32. Therefore we need one -;; version per ISA. - -(define-pmacro (define-call-insn x-endian) - (dni (.sym call x-endian) - "call" - (endian-isas x-endian) - "call $disp32" - (+ disp32 (f-offset16 0) (.sym src x-endian) ((.sym f-dst x-endian) 0) - OP_CLASS_JMP OP_SRC_K OP_CODE_CALL) - (c-call VOID - "bpfbf_call" disp32 (ifield (.sym f-src x-endian))) - ())) - -(define-call-insn le) -(define-call-insn be) - -(define-pmacro (define-callr-insn x-endian) - (dni (.sym callr x-endian) - "callr" - ((ISA (.sym xbpf x-endian))) - (.str "call $dst" x-endian) - (+ (f-imm32 0) (f-offset16 0) ((.sym f-src x-endian) 0) (.sym dst x-endian) - OP_CLASS_JMP OP_SRC_X OP_CODE_CALL) - (c-call VOID - "bpfbf_callr" (ifield (.sym f-dst x-endian))) - ())) - -(define-callr-insn le) -(define-callr-insn be) - -;; The jump-always and `exit' instructions dont make use of either -;; source nor destination registers, so only one variant per -;; instruction is defined. - -(dni ja "ja" (all-isas) "ja $disp16" - (+ (f-imm32 0) disp16 (f-regs 0) - OP_CLASS_JMP OP_SRC_K OP_CODE_JA) - (set DI (reg DI h-pc) (add DI (reg DI h-pc) - (mul DI (add HI disp16 1) 8))) - ()) - -(dni "exit" "exit" (all-isas) "exit" - (+ (f-imm32 0) (f-offset16 0) (f-regs 0) - OP_CLASS_JMP (f-op-src 0) OP_CODE_EXIT) - (c-call VOID "bpfbf_exit") - ()) - -;;; Atomic instructions - -;; The atomic exchange-and-add instructions come in two flavors: one -;; for swapping 64-bit quantities and another for 32-bit quantities. - -(define-pmacro (sem-exchange-and-add x-endian x-mode) - (sequence VOID ((x-mode tmp)) - ;; XXX acquire lock in simulator... as a hardware element? - (set x-mode tmp (mem x-mode (add DI (.sym dst x-endian) offset16))) - (set x-mode - (mem x-mode (add DI (.sym dst x-endian) offset16)) - (add x-mode tmp (.sym src x-endian))))) - -(define-pmacro (define-atomic-insns x-endian) - (begin - (dni (.str "xadddw" x-endian) - "xadddw" - (endian-isas x-endian) - (.str "xadddw [$dst" x-endian "+$offset16],$src" x-endian) - (+ (f-imm32 0) (.sym src x-endian) (.sym dst x-endian) - offset16 OP_MODE_XADD OP_SIZE_DW OP_CLASS_STX) - (sem-exchange-and-add x-endian DI) - ()) - (dni (.str "xaddw" x-endian) - "xaddw" - (endian-isas x-endian) - (.str "xaddw [$dst" x-endian "+$offset16],$src" x-endian) - (+ (f-imm32 0) (.sym src x-endian) (.sym dst x-endian) - offset16 OP_MODE_XADD OP_SIZE_W OP_CLASS_STX) - (sem-exchange-and-add x-endian SI) - ()))) - -(define-atomic-insns le) -(define-atomic-insns be) - -;;; Breakpoint instruction - -;; The brkpt instruction is used by the BPF simulator and it doesn't -;; really belong to the eBPF instruction set. - -(dni "brkpt" "brkpt" (all-isas) "brkpt" - (+ (f-imm32 0) (f-offset16 0) (f-regs 0) - OP_CLASS_ALU OP_SRC_X OP_CODE_NEG) - (c-call VOID "bpfbf_breakpoint") - ()) diff --git a/cpu/bpf.opc b/cpu/bpf.opc deleted file mode 100644 index e70ee04..0000000 --- a/cpu/bpf.opc +++ /dev/null @@ -1,191 +0,0 @@ -/* EBPF opcode support. -*- c -*- - - Copyright (C) 2019 Free Software Foundation, Inc. - - Contributed by Oracle, Inc. - - This file is part of the GNU Binutils and of GDB. - - 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; either version 3 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, - MA 02110-1301, USA. */ - -/* - Each section is delimited with start and end markers. - - -opc.h additions use: "-- opc.h" - -opc.c additions use: "-- opc.c" - -asm.c additions use: "-- asm.c" - -dis.c additions use: "-- dis.c" - -ibd.h additions use: "-- ibd.h". */ - -/* -- opc.h */ - -#undef CGEN_DIS_HASH_SIZE -#define CGEN_DIS_HASH_SIZE 1 - -#undef CGEN_DIS_HASH -#define CGEN_DIS_HASH(buffer, value) 0 - -/* Allows reason codes to be output when assembler errors occur. */ -#define CGEN_VERBOSE_ASSEMBLER_ERRORS - -#define CGEN_VALIDATE_INSN_SUPPORTED -extern int bpf_cgen_insn_supported (CGEN_CPU_DESC, const CGEN_INSN *); - - -/* -- opc.c */ - -/* -- asm.c */ - -/* Parse a signed 64-bit immediate. */ - -static const char * -parse_imm64 (CGEN_CPU_DESC cd, - const char **strp, - int opindex, - int64_t *valuep) -{ - bfd_vma value; - enum cgen_parse_operand_result result; - const char *errmsg; - - errmsg = (* cd->parse_operand_fn) - (cd, CGEN_PARSE_OPERAND_INTEGER, strp, opindex, BFD_RELOC_NONE, - &result, &value); - if (!errmsg) - *valuep = value; - - return errmsg; -} - -/* Endianness size operands are integer immediates whose values can be - 16, 32 or 64. */ - -static const char * -parse_endsize (CGEN_CPU_DESC cd, - const char **strp, - int opindex, - unsigned long *valuep) -{ - const char *errmsg; - - errmsg = cgen_parse_unsigned_integer (cd, strp, opindex, valuep); - if (errmsg) - return errmsg; - - switch (*valuep) - { - case 16: - case 32: - case 64: - break; - default: - return _("expected 16, 32 or 64 in"); - } - - return NULL; -} - -/* Special check to ensure that the right instruction variant is used - for the given endianness induced by the ISA selected in the CPU. - See bpf.cpu for a discussion on how eBPF is really two instruction - sets. */ - -int -bpf_cgen_insn_supported (CGEN_CPU_DESC cd, const CGEN_INSN *insn) -{ - CGEN_BITSET isas = CGEN_INSN_BITSET_ATTR_VALUE (insn, CGEN_INSN_ISA); - - return cgen_bitset_intersect_p (&isas, cd->isas); -} - - -/* -- dis.c */ - -/* We need to customize the disassembler a bit: - - Use 8 bytes per line by default. -*/ - -#define CGEN_PRINT_INSN bpf_print_insn - -static int -bpf_print_insn (CGEN_CPU_DESC cd, bfd_vma pc, disassemble_info *info) -{ - bfd_byte buf[CGEN_MAX_INSN_SIZE]; - int buflen; - int status; - - info->bytes_per_chunk = 1; - info->bytes_per_line = 8; - - /* Attempt to read the base part of the insn. */ - buflen = cd->base_insn_bitsize / 8; - status = (*info->read_memory_func) (pc, buf, buflen, info); - - /* Try again with the minimum part, if min < base. */ - if (status != 0 && (cd->min_insn_bitsize < cd->base_insn_bitsize)) - { - buflen = cd->min_insn_bitsize / 8; - status = (*info->read_memory_func) (pc, buf, buflen, info); - } - - if (status != 0) - { - (*info->memory_error_func) (status, pc, info); - return -1; - } - - return print_insn (cd, pc, info, buf, buflen); -} - -/* Signed immediates should be printed in hexadecimal. */ - -static void -print_immediate (CGEN_CPU_DESC cd ATTRIBUTE_UNUSED, - void *dis_info, - int64_t value, - unsigned int attrs ATTRIBUTE_UNUSED, - bfd_vma pc ATTRIBUTE_UNUSED, - int length ATTRIBUTE_UNUSED) -{ - disassemble_info *info = (disassemble_info *) dis_info; - - if (value <= 9) - (*info->fprintf_func) (info->stream, "%" PRId64, value); - else - (*info->fprintf_func) (info->stream, "%#" PRIx64, value); - - /* This is to avoid -Wunused-function for print_normal. */ - if (0) - print_normal (cd, dis_info, value, attrs, pc, length); -} - -/* Endianness bit sizes should be printed in decimal. */ - -static void -print_endsize (CGEN_CPU_DESC cd ATTRIBUTE_UNUSED, - void *dis_info, - unsigned long value, - unsigned int attrs ATTRIBUTE_UNUSED, - bfd_vma pc ATTRIBUTE_UNUSED, - int length ATTRIBUTE_UNUSED) -{ - disassemble_info *info = (disassemble_info *) dis_info; - (*info->fprintf_func) (info->stream, "%lu", value); -} - - -/* -- */ - -- cgit v1.1