From 5f50930b94a280f79e3bdad2d4f340988079a11f Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Wed, 16 Dec 2020 10:07:31 +0000 Subject: [PATCH] powerpc/bpf: Remove classical BPF support for PPC32 At the time being, PPC32 has Classical BPF support. The test_bpf module exhibits some failure: test_bpf: #298 LD_IND byte frag jited:1 ret 202 != 66 FAIL (1 times) test_bpf: #299 LD_IND halfword frag jited:1 ret 51958 != 17220 FAIL (1 times) test_bpf: #301 LD_IND halfword mixed head/frag jited:1 ret 51958 != 1305 FAIL (1 times) test_bpf: #303 LD_ABS byte frag jited:1 ret 202 != 66 FAIL (1 times) test_bpf: #304 LD_ABS halfword frag jited:1 ret 51958 != 17220 FAIL (1 times) test_bpf: #306 LD_ABS halfword mixed head/frag jited:1 ret 51958 != 1305 FAIL (1 times) test_bpf: Summary: 371 PASSED, 7 FAILED, [119/366 JIT'ed] Fixing this is not worth the effort. Instead, remove support for classical BPF and prepare for adding Extended BPF support instead. Signed-off-by: Christophe Leroy --- arch/powerpc/Kconfig | 1 - arch/powerpc/net/Makefile | 4 - arch/powerpc/net/bpf_jit32.h | 139 ------- arch/powerpc/net/bpf_jit_asm.S | 226 ----------- arch/powerpc/net/bpf_jit_comp.c | 683 -------------------------------- 5 files changed, 1053 deletions(-) delete mode 100644 arch/powerpc/net/bpf_jit32.h delete mode 100644 arch/powerpc/net/bpf_jit_asm.S delete mode 100644 arch/powerpc/net/bpf_jit_comp.c diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index cf328e19930849..6d1454d31a53c0 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -191,7 +191,6 @@ config PPC select HAVE_ARCH_TRACEHOOK select HAVE_ASM_MODVERSIONS select HAVE_C_RECORDMCOUNT - select HAVE_CBPF_JIT if !PPC64 select HAVE_STACKPROTECTOR if PPC64 && $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r13) select HAVE_STACKPROTECTOR if PPC32 && $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r2) select HAVE_CONTEXT_TRACKING if PPC64 diff --git a/arch/powerpc/net/Makefile b/arch/powerpc/net/Makefile index c2dec3a68d4c42..52c939cef5b2ab 100644 --- a/arch/powerpc/net/Makefile +++ b/arch/powerpc/net/Makefile @@ -2,8 +2,4 @@ # # Arch-specific network modules # -ifdef CONFIG_PPC64 obj-$(CONFIG_BPF_JIT) += bpf_jit_comp64.o -else -obj-$(CONFIG_BPF_JIT) += bpf_jit_asm.o bpf_jit_comp.o -endif diff --git a/arch/powerpc/net/bpf_jit32.h b/arch/powerpc/net/bpf_jit32.h deleted file mode 100644 index 448dfd4d98e184..00000000000000 --- a/arch/powerpc/net/bpf_jit32.h +++ /dev/null @@ -1,139 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-only */ -/* - * bpf_jit32.h: BPF JIT compiler for PPC - * - * Copyright 2011 Matt Evans , IBM Corporation - * - * Split from bpf_jit.h - */ -#ifndef _BPF_JIT32_H -#define _BPF_JIT32_H - -#include -#include "bpf_jit.h" - -#ifdef CONFIG_PPC64 -#define BPF_PPC_STACK_R3_OFF 48 -#define BPF_PPC_STACK_LOCALS 32 -#define BPF_PPC_STACK_BASIC (48+64) -#define BPF_PPC_STACK_SAVE (18*8) -#define BPF_PPC_STACKFRAME (BPF_PPC_STACK_BASIC+BPF_PPC_STACK_LOCALS+ \ - BPF_PPC_STACK_SAVE) -#define BPF_PPC_SLOWPATH_FRAME (48+64) -#else -#define BPF_PPC_STACK_R3_OFF 24 -#define BPF_PPC_STACK_LOCALS 16 -#define BPF_PPC_STACK_BASIC (24+32) -#define BPF_PPC_STACK_SAVE (18*4) -#define BPF_PPC_STACKFRAME (BPF_PPC_STACK_BASIC+BPF_PPC_STACK_LOCALS+ \ - BPF_PPC_STACK_SAVE) -#define BPF_PPC_SLOWPATH_FRAME (24+32) -#endif - -#define REG_SZ (BITS_PER_LONG/8) - -/* - * Generated code register usage: - * - * As normal PPC C ABI (e.g. r1=sp, r2=TOC), with: - * - * skb r3 (Entry parameter) - * A register r4 - * X register r5 - * addr param r6 - * r7-r10 scratch - * skb->data r14 - * skb headlen r15 (skb->len - skb->data_len) - * m[0] r16 - * m[...] ... - * m[15] r31 - */ -#define r_skb 3 -#define r_ret 3 -#define r_A 4 -#define r_X 5 -#define r_addr 6 -#define r_scratch1 7 -#define r_scratch2 8 -#define r_D 14 -#define r_HL 15 -#define r_M 16 - -#ifndef __ASSEMBLY__ - -/* - * Assembly helpers from arch/powerpc/net/bpf_jit.S: - */ -#define DECLARE_LOAD_FUNC(func) \ - extern u8 func[], func##_negative_offset[], func##_positive_offset[] - -DECLARE_LOAD_FUNC(sk_load_word); -DECLARE_LOAD_FUNC(sk_load_half); -DECLARE_LOAD_FUNC(sk_load_byte); -DECLARE_LOAD_FUNC(sk_load_byte_msh); - -#define PPC_LBZ_OFFS(r, base, i) do { if ((i) < 32768) EMIT(PPC_RAW_LBZ(r, base, i)); \ - else { EMIT(PPC_RAW_ADDIS(r, base, IMM_HA(i))); \ - EMIT(PPC_RAW_LBZ(r, r, IMM_L(i))); } } while(0) - -#define PPC_LD_OFFS(r, base, i) do { if ((i) < 32768) EMIT(PPC_RAW_LD(r, base, i)); \ - else { EMIT(PPC_RAW_ADDIS(r, base, IMM_HA(i))); \ - EMIT(PPC_RAW_LD(r, r, IMM_L(i))); } } while(0) - -#define PPC_LWZ_OFFS(r, base, i) do { if ((i) < 32768) EMIT(PPC_RAW_LWZ(r, base, i)); \ - else { EMIT(PPC_RAW_ADDIS(r, base, IMM_HA(i))); \ - EMIT(PPC_RAW_LWZ(r, r, IMM_L(i))); } } while(0) - -#define PPC_LHZ_OFFS(r, base, i) do { if ((i) < 32768) EMIT(PPC_RAW_LHZ(r, base, i)); \ - else { EMIT(PPC_RAW_ADDIS(r, base, IMM_HA(i))); \ - EMIT(PPC_RAW_LHZ(r, r, IMM_L(i))); } } while(0) - -#ifdef CONFIG_PPC64 -#define PPC_LL_OFFS(r, base, i) do { PPC_LD_OFFS(r, base, i); } while(0) -#else -#define PPC_LL_OFFS(r, base, i) do { PPC_LWZ_OFFS(r, base, i); } while(0) -#endif - -#ifdef CONFIG_SMP -#ifdef CONFIG_PPC64 -#define PPC_BPF_LOAD_CPU(r) \ - do { BUILD_BUG_ON(sizeof_field(struct paca_struct, paca_index) != 2); \ - PPC_LHZ_OFFS(r, 13, offsetof(struct paca_struct, paca_index)); \ - } while (0) -#else -#define PPC_BPF_LOAD_CPU(r) \ - do { BUILD_BUG_ON(sizeof_field(struct task_struct, cpu) != 4); \ - PPC_LHZ_OFFS(r, 2, offsetof(struct task_struct, cpu)); \ - } while(0) -#endif -#else -#define PPC_BPF_LOAD_CPU(r) do { EMIT(PPC_RAW_LI(r, 0)); } while(0) -#endif - -#define PPC_LHBRX_OFFS(r, base, i) \ - do { PPC_LI32(r, i); EMIT(PPC_RAW_LHBRX(r, r, base)); } while(0) -#ifdef __LITTLE_ENDIAN__ -#define PPC_NTOHS_OFFS(r, base, i) PPC_LHBRX_OFFS(r, base, i) -#else -#define PPC_NTOHS_OFFS(r, base, i) PPC_LHZ_OFFS(r, base, i) -#endif - -#define PPC_BPF_LL(r, base, i) do { EMIT(PPC_RAW_LWZ(r, base, i)); } while(0) -#define PPC_BPF_STL(r, base, i) do { EMIT(PPC_RAW_STW(r, base, i)); } while(0) -#define PPC_BPF_STLU(r, base, i) do { EMIT(PPC_RAW_STWU(r, base, i)); } while(0) - -#define SEEN_DATAREF 0x10000 /* might call external helpers */ -#define SEEN_XREG 0x20000 /* X reg is used */ -#define SEEN_MEM 0x40000 /* SEEN_MEM+(1<, IBM Corporation - */ - -#include -#include -#include "bpf_jit32.h" - -/* - * All of these routines are called directly from generated code, - * whose register usage is: - * - * r3 skb - * r4,r5 A,X - * r6 *** address parameter to helper *** - * r7-r10 scratch - * r14 skb->data - * r15 skb headlen - * r16-31 M[] - */ - -/* - * To consider: These helpers are so small it could be better to just - * generate them inline. Inline code can do the simple headlen check - * then branch directly to slow_path_XXX if required. (In fact, could - * load a spare GPR with the address of slow_path_generic and pass size - * as an argument, making the call site a mtlr, li and bllr.) - */ - .globl sk_load_word -sk_load_word: - PPC_LCMPI r_addr, 0 - blt bpf_slow_path_word_neg - .globl sk_load_word_positive_offset -sk_load_word_positive_offset: - /* Are we accessing past headlen? */ - subi r_scratch1, r_HL, 4 - PPC_LCMP r_scratch1, r_addr - blt bpf_slow_path_word - /* Nope, just hitting the header. cr0 here is eq or gt! */ -#ifdef __LITTLE_ENDIAN__ - lwbrx r_A, r_D, r_addr -#else - lwzx r_A, r_D, r_addr -#endif - blr /* Return success, cr0 != LT */ - - .globl sk_load_half -sk_load_half: - PPC_LCMPI r_addr, 0 - blt bpf_slow_path_half_neg - .globl sk_load_half_positive_offset -sk_load_half_positive_offset: - subi r_scratch1, r_HL, 2 - PPC_LCMP r_scratch1, r_addr - blt bpf_slow_path_half -#ifdef __LITTLE_ENDIAN__ - lhbrx r_A, r_D, r_addr -#else - lhzx r_A, r_D, r_addr -#endif - blr - - .globl sk_load_byte -sk_load_byte: - PPC_LCMPI r_addr, 0 - blt bpf_slow_path_byte_neg - .globl sk_load_byte_positive_offset -sk_load_byte_positive_offset: - PPC_LCMP r_HL, r_addr - ble bpf_slow_path_byte - lbzx r_A, r_D, r_addr - blr - -/* - * BPF_LDX | BPF_B | BPF_MSH: ldxb 4*([offset]&0xf) - * r_addr is the offset value - */ - .globl sk_load_byte_msh -sk_load_byte_msh: - PPC_LCMPI r_addr, 0 - blt bpf_slow_path_byte_msh_neg - .globl sk_load_byte_msh_positive_offset -sk_load_byte_msh_positive_offset: - PPC_LCMP r_HL, r_addr - ble bpf_slow_path_byte_msh - lbzx r_X, r_D, r_addr - rlwinm r_X, r_X, 2, 32-4-2, 31-2 - blr - -/* Call out to skb_copy_bits: - * We'll need to back up our volatile regs first; we have - * local variable space at r1+(BPF_PPC_STACK_BASIC). - * Allocate a new stack frame here to remain ABI-compliant in - * stashing LR. - */ -#define bpf_slow_path_common(SIZE) \ - mflr r0; \ - PPC_STL r0, PPC_LR_STKOFF(r1); \ - /* R3 goes in parameter space of caller's frame */ \ - PPC_STL r_skb, (BPF_PPC_STACKFRAME+BPF_PPC_STACK_R3_OFF)(r1); \ - PPC_STL r_A, (BPF_PPC_STACK_BASIC+(0*REG_SZ))(r1); \ - PPC_STL r_X, (BPF_PPC_STACK_BASIC+(1*REG_SZ))(r1); \ - addi r5, r1, BPF_PPC_STACK_BASIC+(2*REG_SZ); \ - PPC_STLU r1, -BPF_PPC_SLOWPATH_FRAME(r1); \ - /* R3 = r_skb, as passed */ \ - mr r4, r_addr; \ - li r6, SIZE; \ - bl skb_copy_bits; \ - nop; \ - /* R3 = 0 on success */ \ - addi r1, r1, BPF_PPC_SLOWPATH_FRAME; \ - PPC_LL r0, PPC_LR_STKOFF(r1); \ - PPC_LL r_A, (BPF_PPC_STACK_BASIC+(0*REG_SZ))(r1); \ - PPC_LL r_X, (BPF_PPC_STACK_BASIC+(1*REG_SZ))(r1); \ - mtlr r0; \ - PPC_LCMPI r3, 0; \ - blt bpf_error; /* cr0 = LT */ \ - PPC_LL r_skb, (BPF_PPC_STACKFRAME+BPF_PPC_STACK_R3_OFF)(r1); \ - /* Great success! */ - -bpf_slow_path_word: - bpf_slow_path_common(4) - /* Data value is on stack, and cr0 != LT */ - lwz r_A, BPF_PPC_STACK_BASIC+(2*REG_SZ)(r1) - blr - -bpf_slow_path_half: - bpf_slow_path_common(2) - lhz r_A, BPF_PPC_STACK_BASIC+(2*8)(r1) - blr - -bpf_slow_path_byte: - bpf_slow_path_common(1) - lbz r_A, BPF_PPC_STACK_BASIC+(2*8)(r1) - blr - -bpf_slow_path_byte_msh: - bpf_slow_path_common(1) - lbz r_X, BPF_PPC_STACK_BASIC+(2*8)(r1) - rlwinm r_X, r_X, 2, 32-4-2, 31-2 - blr - -/* Call out to bpf_internal_load_pointer_neg_helper: - * We'll need to back up our volatile regs first; we have - * local variable space at r1+(BPF_PPC_STACK_BASIC). - * Allocate a new stack frame here to remain ABI-compliant in - * stashing LR. - */ -#define sk_negative_common(SIZE) \ - mflr r0; \ - PPC_STL r0, PPC_LR_STKOFF(r1); \ - /* R3 goes in parameter space of caller's frame */ \ - PPC_STL r_skb, (BPF_PPC_STACKFRAME+BPF_PPC_STACK_R3_OFF)(r1); \ - PPC_STL r_A, (BPF_PPC_STACK_BASIC+(0*REG_SZ))(r1); \ - PPC_STL r_X, (BPF_PPC_STACK_BASIC+(1*REG_SZ))(r1); \ - PPC_STLU r1, -BPF_PPC_SLOWPATH_FRAME(r1); \ - /* R3 = r_skb, as passed */ \ - mr r4, r_addr; \ - li r5, SIZE; \ - bl bpf_internal_load_pointer_neg_helper; \ - nop; \ - /* R3 != 0 on success */ \ - addi r1, r1, BPF_PPC_SLOWPATH_FRAME; \ - PPC_LL r0, PPC_LR_STKOFF(r1); \ - PPC_LL r_A, (BPF_PPC_STACK_BASIC+(0*REG_SZ))(r1); \ - PPC_LL r_X, (BPF_PPC_STACK_BASIC+(1*REG_SZ))(r1); \ - mtlr r0; \ - PPC_LCMPLI r3, 0; \ - beq bpf_error_slow; /* cr0 = EQ */ \ - mr r_addr, r3; \ - PPC_LL r_skb, (BPF_PPC_STACKFRAME+BPF_PPC_STACK_R3_OFF)(r1); \ - /* Great success! */ - -bpf_slow_path_word_neg: - lis r_scratch1,-32 /* SKF_LL_OFF */ - PPC_LCMP r_addr, r_scratch1 /* addr < SKF_* */ - blt bpf_error /* cr0 = LT */ - .globl sk_load_word_negative_offset -sk_load_word_negative_offset: - sk_negative_common(4) - lwz r_A, 0(r_addr) - blr - -bpf_slow_path_half_neg: - lis r_scratch1,-32 /* SKF_LL_OFF */ - PPC_LCMP r_addr, r_scratch1 /* addr < SKF_* */ - blt bpf_error /* cr0 = LT */ - .globl sk_load_half_negative_offset -sk_load_half_negative_offset: - sk_negative_common(2) - lhz r_A, 0(r_addr) - blr - -bpf_slow_path_byte_neg: - lis r_scratch1,-32 /* SKF_LL_OFF */ - PPC_LCMP r_addr, r_scratch1 /* addr < SKF_* */ - blt bpf_error /* cr0 = LT */ - .globl sk_load_byte_negative_offset -sk_load_byte_negative_offset: - sk_negative_common(1) - lbz r_A, 0(r_addr) - blr - -bpf_slow_path_byte_msh_neg: - lis r_scratch1,-32 /* SKF_LL_OFF */ - PPC_LCMP r_addr, r_scratch1 /* addr < SKF_* */ - blt bpf_error /* cr0 = LT */ - .globl sk_load_byte_msh_negative_offset -sk_load_byte_msh_negative_offset: - sk_negative_common(1) - lbz r_X, 0(r_addr) - rlwinm r_X, r_X, 2, 32-4-2, 31-2 - blr - -bpf_error_slow: - /* fabricate a cr0 = lt */ - li r_scratch1, -1 - PPC_LCMPI r_scratch1, 0 -bpf_error: - /* Entered with cr0 = lt */ - li r3, 0 - /* Generated code will 'blt epilogue', returning 0. */ - blr diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c deleted file mode 100644 index e809cb5a16316b..00000000000000 --- a/arch/powerpc/net/bpf_jit_comp.c +++ /dev/null @@ -1,683 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* bpf_jit_comp.c: BPF JIT compiler - * - * Copyright 2011 Matt Evans , IBM Corporation - * - * Based on the x86 BPF compiler, by Eric Dumazet (eric.dumazet@gmail.com) - * Ported to ppc32 by Denis Kirjanov - */ -#include -#include -#include -#include -#include -#include - -#include "bpf_jit32.h" - -static inline void bpf_flush_icache(void *start, void *end) -{ - smp_wmb(); - flush_icache_range((unsigned long)start, (unsigned long)end); -} - -static void bpf_jit_build_prologue(struct bpf_prog *fp, u32 *image, - struct codegen_context *ctx) -{ - int i; - const struct sock_filter *filter = fp->insns; - - if (ctx->seen & (SEEN_MEM | SEEN_DATAREF)) { - /* Make stackframe */ - if (ctx->seen & SEEN_DATAREF) { - /* If we call any helpers (for loads), save LR */ - EMIT(PPC_INST_MFLR | __PPC_RT(R0)); - PPC_BPF_STL(0, 1, PPC_LR_STKOFF); - - /* Back up non-volatile regs. */ - PPC_BPF_STL(r_D, 1, -(REG_SZ*(32-r_D))); - PPC_BPF_STL(r_HL, 1, -(REG_SZ*(32-r_HL))); - } - if (ctx->seen & SEEN_MEM) { - /* - * Conditionally save regs r15-r31 as some will be used - * for M[] data. - */ - for (i = r_M; i < (r_M+16); i++) { - if (ctx->seen & (1 << (i-r_M))) - PPC_BPF_STL(i, 1, -(REG_SZ*(32-i))); - } - } - PPC_BPF_STLU(1, 1, -BPF_PPC_STACKFRAME); - } - - if (ctx->seen & SEEN_DATAREF) { - /* - * If this filter needs to access skb data, - * prepare r_D and r_HL: - * r_HL = skb->len - skb->data_len - * r_D = skb->data - */ - PPC_LWZ_OFFS(r_scratch1, r_skb, offsetof(struct sk_buff, - data_len)); - PPC_LWZ_OFFS(r_HL, r_skb, offsetof(struct sk_buff, len)); - EMIT(PPC_RAW_SUB(r_HL, r_HL, r_scratch1)); - PPC_LL_OFFS(r_D, r_skb, offsetof(struct sk_buff, data)); - } - - if (ctx->seen & SEEN_XREG) { - /* - * TODO: Could also detect whether first instr. sets X and - * avoid this (as below, with A). - */ - EMIT(PPC_RAW_LI(r_X, 0)); - } - - /* make sure we dont leak kernel information to user */ - if (bpf_needs_clear_a(&filter[0])) - EMIT(PPC_RAW_LI(r_A, 0)); -} - -static void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) -{ - int i; - - if (ctx->seen & (SEEN_MEM | SEEN_DATAREF)) { - EMIT(PPC_RAW_ADDI(1, 1, BPF_PPC_STACKFRAME)); - if (ctx->seen & SEEN_DATAREF) { - PPC_BPF_LL(0, 1, PPC_LR_STKOFF); - EMIT(PPC_RAW_MTLR(0)); - PPC_BPF_LL(r_D, 1, -(REG_SZ*(32-r_D))); - PPC_BPF_LL(r_HL, 1, -(REG_SZ*(32-r_HL))); - } - if (ctx->seen & SEEN_MEM) { - /* Restore any saved non-vol registers */ - for (i = r_M; i < (r_M+16); i++) { - if (ctx->seen & (1 << (i-r_M))) - PPC_BPF_LL(i, 1, -(REG_SZ*(32-i))); - } - } - } - /* The RETs have left a return value in R3. */ - - EMIT(PPC_RAW_BLR()); -} - -#define CHOOSE_LOAD_FUNC(K, func) \ - ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset) - -/* Assemble the body code between the prologue & epilogue. */ -static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, - struct codegen_context *ctx, - unsigned int *addrs) -{ - const struct sock_filter *filter = fp->insns; - int flen = fp->len; - u8 *func; - unsigned int true_cond; - int i; - - /* Start of epilogue code */ - unsigned int exit_addr = addrs[flen]; - - for (i = 0; i < flen; i++) { - unsigned int K = filter[i].k; - u16 code = bpf_anc_helper(&filter[i]); - - /* - * addrs[] maps a BPF bytecode address into a real offset from - * the start of the body code. - */ - addrs[i] = ctx->idx * 4; - - switch (code) { - /*** ALU ops ***/ - case BPF_ALU | BPF_ADD | BPF_X: /* A += X; */ - ctx->seen |= SEEN_XREG; - EMIT(PPC_RAW_ADD(r_A, r_A, r_X)); - break; - case BPF_ALU | BPF_ADD | BPF_K: /* A += K; */ - if (!K) - break; - EMIT(PPC_RAW_ADDI(r_A, r_A, IMM_L(K))); - if (K >= 32768) - EMIT(PPC_RAW_ADDIS(r_A, r_A, IMM_HA(K))); - break; - case BPF_ALU | BPF_SUB | BPF_X: /* A -= X; */ - ctx->seen |= SEEN_XREG; - EMIT(PPC_RAW_SUB(r_A, r_A, r_X)); - break; - case BPF_ALU | BPF_SUB | BPF_K: /* A -= K */ - if (!K) - break; - EMIT(PPC_RAW_ADDI(r_A, r_A, IMM_L(-K))); - if (K >= 32768) - EMIT(PPC_RAW_ADDIS(r_A, r_A, IMM_HA(-K))); - break; - case BPF_ALU | BPF_MUL | BPF_X: /* A *= X; */ - ctx->seen |= SEEN_XREG; - EMIT(PPC_RAW_MULW(r_A, r_A, r_X)); - break; - case BPF_ALU | BPF_MUL | BPF_K: /* A *= K */ - if (K < 32768) - EMIT(PPC_RAW_MULI(r_A, r_A, K)); - else { - PPC_LI32(r_scratch1, K); - EMIT(PPC_RAW_MULW(r_A, r_A, r_scratch1)); - } - break; - case BPF_ALU | BPF_MOD | BPF_X: /* A %= X; */ - case BPF_ALU | BPF_DIV | BPF_X: /* A /= X; */ - ctx->seen |= SEEN_XREG; - EMIT(PPC_RAW_CMPWI(r_X, 0)); - if (ctx->pc_ret0 != -1) { - PPC_BCC(COND_EQ, addrs[ctx->pc_ret0]); - } else { - PPC_BCC_SHORT(COND_NE, (ctx->idx*4)+12); - EMIT(PPC_RAW_LI(r_ret, 0)); - PPC_JMP(exit_addr); - } - if (code == (BPF_ALU | BPF_MOD | BPF_X)) { - EMIT(PPC_RAW_DIVWU(r_scratch1, r_A, r_X)); - EMIT(PPC_RAW_MULW(r_scratch1, r_X, r_scratch1)); - EMIT(PPC_RAW_SUB(r_A, r_A, r_scratch1)); - } else { - EMIT(PPC_RAW_DIVWU(r_A, r_A, r_X)); - } - break; - case BPF_ALU | BPF_MOD | BPF_K: /* A %= K; */ - PPC_LI32(r_scratch2, K); - EMIT(PPC_RAW_DIVWU(r_scratch1, r_A, r_scratch2)); - EMIT(PPC_RAW_MULW(r_scratch1, r_scratch2, r_scratch1)); - EMIT(PPC_RAW_SUB(r_A, r_A, r_scratch1)); - break; - case BPF_ALU | BPF_DIV | BPF_K: /* A /= K */ - if (K == 1) - break; - PPC_LI32(r_scratch1, K); - EMIT(PPC_RAW_DIVWU(r_A, r_A, r_scratch1)); - break; - case BPF_ALU | BPF_AND | BPF_X: - ctx->seen |= SEEN_XREG; - EMIT(PPC_RAW_AND(r_A, r_A, r_X)); - break; - case BPF_ALU | BPF_AND | BPF_K: - if (!IMM_H(K)) - EMIT(PPC_RAW_ANDI(r_A, r_A, K)); - else { - PPC_LI32(r_scratch1, K); - EMIT(PPC_RAW_AND(r_A, r_A, r_scratch1)); - } - break; - case BPF_ALU | BPF_OR | BPF_X: - ctx->seen |= SEEN_XREG; - EMIT(PPC_RAW_OR(r_A, r_A, r_X)); - break; - case BPF_ALU | BPF_OR | BPF_K: - if (IMM_L(K)) - EMIT(PPC_RAW_ORI(r_A, r_A, IMM_L(K))); - if (K >= 65536) - EMIT(PPC_RAW_ORIS(r_A, r_A, IMM_H(K))); - break; - case BPF_ANC | SKF_AD_ALU_XOR_X: - case BPF_ALU | BPF_XOR | BPF_X: /* A ^= X */ - ctx->seen |= SEEN_XREG; - EMIT(PPC_RAW_XOR(r_A, r_A, r_X)); - break; - case BPF_ALU | BPF_XOR | BPF_K: /* A ^= K */ - if (IMM_L(K)) - EMIT(PPC_RAW_XORI(r_A, r_A, IMM_L(K))); - if (K >= 65536) - EMIT(PPC_RAW_XORIS(r_A, r_A, IMM_H(K))); - break; - case BPF_ALU | BPF_LSH | BPF_X: /* A <<= X; */ - ctx->seen |= SEEN_XREG; - EMIT(PPC_RAW_SLW(r_A, r_A, r_X)); - break; - case BPF_ALU | BPF_LSH | BPF_K: - if (K == 0) - break; - else - EMIT(PPC_RAW_SLWI(r_A, r_A, K)); - break; - case BPF_ALU | BPF_RSH | BPF_X: /* A >>= X; */ - ctx->seen |= SEEN_XREG; - EMIT(PPC_RAW_SRW(r_A, r_A, r_X)); - break; - case BPF_ALU | BPF_RSH | BPF_K: /* A >>= K; */ - if (K == 0) - break; - else - EMIT(PPC_RAW_SRWI(r_A, r_A, K)); - break; - case BPF_ALU | BPF_NEG: - EMIT(PPC_RAW_NEG(r_A, r_A)); - break; - case BPF_RET | BPF_K: - PPC_LI32(r_ret, K); - if (!K) { - if (ctx->pc_ret0 == -1) - ctx->pc_ret0 = i; - } - /* - * If this isn't the very last instruction, branch to - * the epilogue if we've stuff to clean up. Otherwise, - * if there's nothing to tidy, just return. If we /are/ - * the last instruction, we're about to fall through to - * the epilogue to return. - */ - if (i != flen - 1) { - /* - * Note: 'seen' is properly valid only on pass - * #2. Both parts of this conditional are the - * same instruction size though, meaning the - * first pass will still correctly determine the - * code size/addresses. - */ - if (ctx->seen) - PPC_JMP(exit_addr); - else - EMIT(PPC_RAW_BLR()); - } - break; - case BPF_RET | BPF_A: - EMIT(PPC_RAW_MR(r_ret, r_A)); - if (i != flen - 1) { - if (ctx->seen) - PPC_JMP(exit_addr); - else - EMIT(PPC_RAW_BLR()); - } - break; - case BPF_MISC | BPF_TAX: /* X = A */ - EMIT(PPC_RAW_MR(r_X, r_A)); - break; - case BPF_MISC | BPF_TXA: /* A = X */ - ctx->seen |= SEEN_XREG; - EMIT(PPC_RAW_MR(r_A, r_X)); - break; - - /*** Constant loads/M[] access ***/ - case BPF_LD | BPF_IMM: /* A = K */ - PPC_LI32(r_A, K); - break; - case BPF_LDX | BPF_IMM: /* X = K */ - PPC_LI32(r_X, K); - break; - case BPF_LD | BPF_MEM: /* A = mem[K] */ - EMIT(PPC_RAW_MR(r_A, r_M + (K & 0xf))); - ctx->seen |= SEEN_MEM | (1<<(K & 0xf)); - break; - case BPF_LDX | BPF_MEM: /* X = mem[K] */ - EMIT(PPC_RAW_MR(r_X, r_M + (K & 0xf))); - ctx->seen |= SEEN_MEM | (1<<(K & 0xf)); - break; - case BPF_ST: /* mem[K] = A */ - EMIT(PPC_RAW_MR(r_M + (K & 0xf), r_A)); - ctx->seen |= SEEN_MEM | (1<<(K & 0xf)); - break; - case BPF_STX: /* mem[K] = X */ - EMIT(PPC_RAW_MR(r_M + (K & 0xf), r_X)); - ctx->seen |= SEEN_XREG | SEEN_MEM | (1<<(K & 0xf)); - break; - case BPF_LD | BPF_W | BPF_LEN: /* A = skb->len; */ - BUILD_BUG_ON(sizeof_field(struct sk_buff, len) != 4); - PPC_LWZ_OFFS(r_A, r_skb, offsetof(struct sk_buff, len)); - break; - case BPF_LDX | BPF_W | BPF_ABS: /* A = *((u32 *)(seccomp_data + K)); */ - PPC_LWZ_OFFS(r_A, r_skb, K); - break; - case BPF_LDX | BPF_W | BPF_LEN: /* X = skb->len; */ - PPC_LWZ_OFFS(r_X, r_skb, offsetof(struct sk_buff, len)); - break; - - /*** Ancillary info loads ***/ - case BPF_ANC | SKF_AD_PROTOCOL: /* A = ntohs(skb->protocol); */ - BUILD_BUG_ON(sizeof_field(struct sk_buff, - protocol) != 2); - PPC_NTOHS_OFFS(r_A, r_skb, offsetof(struct sk_buff, - protocol)); - break; - case BPF_ANC | SKF_AD_IFINDEX: - case BPF_ANC | SKF_AD_HATYPE: - BUILD_BUG_ON(sizeof_field(struct net_device, - ifindex) != 4); - BUILD_BUG_ON(sizeof_field(struct net_device, - type) != 2); - PPC_LL_OFFS(r_scratch1, r_skb, offsetof(struct sk_buff, - dev)); - EMIT(PPC_RAW_CMPDI(r_scratch1, 0)); - if (ctx->pc_ret0 != -1) { - PPC_BCC(COND_EQ, addrs[ctx->pc_ret0]); - } else { - /* Exit, returning 0; first pass hits here. */ - PPC_BCC_SHORT(COND_NE, ctx->idx * 4 + 12); - EMIT(PPC_RAW_LI(r_ret, 0)); - PPC_JMP(exit_addr); - } - if (code == (BPF_ANC | SKF_AD_IFINDEX)) { - PPC_LWZ_OFFS(r_A, r_scratch1, - offsetof(struct net_device, ifindex)); - } else { - PPC_LHZ_OFFS(r_A, r_scratch1, - offsetof(struct net_device, type)); - } - - break; - case BPF_ANC | SKF_AD_MARK: - BUILD_BUG_ON(sizeof_field(struct sk_buff, mark) != 4); - PPC_LWZ_OFFS(r_A, r_skb, offsetof(struct sk_buff, - mark)); - break; - case BPF_ANC | SKF_AD_RXHASH: - BUILD_BUG_ON(sizeof_field(struct sk_buff, hash) != 4); - PPC_LWZ_OFFS(r_A, r_skb, offsetof(struct sk_buff, - hash)); - break; - case BPF_ANC | SKF_AD_VLAN_TAG: - BUILD_BUG_ON(sizeof_field(struct sk_buff, vlan_tci) != 2); - - PPC_LHZ_OFFS(r_A, r_skb, offsetof(struct sk_buff, - vlan_tci)); - break; - case BPF_ANC | SKF_AD_VLAN_TAG_PRESENT: - PPC_LBZ_OFFS(r_A, r_skb, PKT_VLAN_PRESENT_OFFSET()); - if (PKT_VLAN_PRESENT_BIT) - EMIT(PPC_RAW_SRWI(r_A, r_A, PKT_VLAN_PRESENT_BIT)); - if (PKT_VLAN_PRESENT_BIT < 7) - EMIT(PPC_RAW_ANDI(r_A, r_A, 1)); - break; - case BPF_ANC | SKF_AD_QUEUE: - BUILD_BUG_ON(sizeof_field(struct sk_buff, - queue_mapping) != 2); - PPC_LHZ_OFFS(r_A, r_skb, offsetof(struct sk_buff, - queue_mapping)); - break; - case BPF_ANC | SKF_AD_PKTTYPE: - PPC_LBZ_OFFS(r_A, r_skb, PKT_TYPE_OFFSET()); - EMIT(PPC_RAW_ANDI(r_A, r_A, PKT_TYPE_MAX)); - EMIT(PPC_RAW_SRWI(r_A, r_A, 5)); - break; - case BPF_ANC | SKF_AD_CPU: - PPC_BPF_LOAD_CPU(r_A); - break; - /*** Absolute loads from packet header/data ***/ - case BPF_LD | BPF_W | BPF_ABS: - func = CHOOSE_LOAD_FUNC(K, sk_load_word); - goto common_load; - case BPF_LD | BPF_H | BPF_ABS: - func = CHOOSE_LOAD_FUNC(K, sk_load_half); - goto common_load; - case BPF_LD | BPF_B | BPF_ABS: - func = CHOOSE_LOAD_FUNC(K, sk_load_byte); - common_load: - /* Load from [K]. */ - ctx->seen |= SEEN_DATAREF; - PPC_FUNC_ADDR(r_scratch1, func); - EMIT(PPC_RAW_MTLR(r_scratch1)); - PPC_LI32(r_addr, K); - EMIT(PPC_RAW_BLRL()); - /* - * Helper returns 'lt' condition on error, and an - * appropriate return value in r3 - */ - PPC_BCC(COND_LT, exit_addr); - break; - - /*** Indirect loads from packet header/data ***/ - case BPF_LD | BPF_W | BPF_IND: - func = sk_load_word; - goto common_load_ind; - case BPF_LD | BPF_H | BPF_IND: - func = sk_load_half; - goto common_load_ind; - case BPF_LD | BPF_B | BPF_IND: - func = sk_load_byte; - common_load_ind: - /* - * Load from [X + K]. Negative offsets are tested for - * in the helper functions. - */ - ctx->seen |= SEEN_DATAREF | SEEN_XREG; - PPC_FUNC_ADDR(r_scratch1, func); - EMIT(PPC_RAW_MTLR(r_scratch1)); - EMIT(PPC_RAW_ADDI(r_addr, r_X, IMM_L(K))); - if (K >= 32768) - EMIT(PPC_RAW_ADDIS(r_addr, r_addr, IMM_HA(K))); - EMIT(PPC_RAW_BLRL()); - /* If error, cr0.LT set */ - PPC_BCC(COND_LT, exit_addr); - break; - - case BPF_LDX | BPF_B | BPF_MSH: - func = CHOOSE_LOAD_FUNC(K, sk_load_byte_msh); - goto common_load; - break; - - /*** Jump and branches ***/ - case BPF_JMP | BPF_JA: - if (K != 0) - PPC_JMP(addrs[i + 1 + K]); - break; - - case BPF_JMP | BPF_JGT | BPF_K: - case BPF_JMP | BPF_JGT | BPF_X: - true_cond = COND_GT; - goto cond_branch; - case BPF_JMP | BPF_JGE | BPF_K: - case BPF_JMP | BPF_JGE | BPF_X: - true_cond = COND_GE; - goto cond_branch; - case BPF_JMP | BPF_JEQ | BPF_K: - case BPF_JMP | BPF_JEQ | BPF_X: - true_cond = COND_EQ; - goto cond_branch; - case BPF_JMP | BPF_JSET | BPF_K: - case BPF_JMP | BPF_JSET | BPF_X: - true_cond = COND_NE; - cond_branch: - /* same targets, can avoid doing the test :) */ - if (filter[i].jt == filter[i].jf) { - if (filter[i].jt > 0) - PPC_JMP(addrs[i + 1 + filter[i].jt]); - break; - } - - switch (code) { - case BPF_JMP | BPF_JGT | BPF_X: - case BPF_JMP | BPF_JGE | BPF_X: - case BPF_JMP | BPF_JEQ | BPF_X: - ctx->seen |= SEEN_XREG; - EMIT(PPC_RAW_CMPLW(r_A, r_X)); - break; - case BPF_JMP | BPF_JSET | BPF_X: - ctx->seen |= SEEN_XREG; - EMIT(PPC_RAW_AND_DOT(r_scratch1, r_A, r_X)); - break; - case BPF_JMP | BPF_JEQ | BPF_K: - case BPF_JMP | BPF_JGT | BPF_K: - case BPF_JMP | BPF_JGE | BPF_K: - if (K < 32768) - EMIT(PPC_RAW_CMPLWI(r_A, K)); - else { - PPC_LI32(r_scratch1, K); - EMIT(PPC_RAW_CMPLW(r_A, r_scratch1)); - } - break; - case BPF_JMP | BPF_JSET | BPF_K: - if (K < 32768) - /* PPC_ANDI is /only/ dot-form */ - EMIT(PPC_RAW_ANDI(r_scratch1, r_A, K)); - else { - PPC_LI32(r_scratch1, K); - EMIT(PPC_RAW_AND_DOT(r_scratch1, r_A, - r_scratch1)); - } - break; - } - /* Sometimes branches are constructed "backward", with - * the false path being the branch and true path being - * a fallthrough to the next instruction. - */ - if (filter[i].jt == 0) - /* Swap the sense of the branch */ - PPC_BCC(true_cond ^ COND_CMP_TRUE, - addrs[i + 1 + filter[i].jf]); - else { - PPC_BCC(true_cond, addrs[i + 1 + filter[i].jt]); - if (filter[i].jf != 0) - PPC_JMP(addrs[i + 1 + filter[i].jf]); - } - break; - default: - /* The filter contains something cruel & unusual. - * We don't handle it, but also there shouldn't be - * anything missing from our list. - */ - if (printk_ratelimit()) - pr_err("BPF filter opcode %04x (@%d) unsupported\n", - filter[i].code, i); - return -ENOTSUPP; - } - - } - /* Set end-of-body-code address for exit. */ - addrs[i] = ctx->idx * 4; - - return 0; -} - -void bpf_jit_compile(struct bpf_prog *fp) -{ - unsigned int proglen; - unsigned int alloclen; - u32 *image = NULL; - u32 *code_base; - unsigned int *addrs; - struct codegen_context cgctx; - int pass; - int flen = fp->len; - - if (!bpf_jit_enable) - return; - - addrs = kcalloc(flen + 1, sizeof(*addrs), GFP_KERNEL); - if (addrs == NULL) - return; - - /* - * There are multiple assembly passes as the generated code will change - * size as it settles down, figuring out the max branch offsets/exit - * paths required. - * - * The range of standard conditional branches is +/- 32Kbytes. Since - * BPF_MAXINSNS = 4096, we can only jump from (worst case) start to - * finish with 8 bytes/instruction. Not feasible, so long jumps are - * used, distinct from short branches. - * - * Current: - * - * For now, both branch types assemble to 2 words (short branches padded - * with a NOP); this is less efficient, but assembly will always complete - * after exactly 3 passes: - * - * First pass: No code buffer; Program is "faux-generated" -- no code - * emitted but maximum size of output determined (and addrs[] filled - * in). Also, we note whether we use M[], whether we use skb data, etc. - * All generation choices assumed to be 'worst-case', e.g. branches all - * far (2 instructions), return path code reduction not available, etc. - * - * Second pass: Code buffer allocated with size determined previously. - * Prologue generated to support features we have seen used. Exit paths - * determined and addrs[] is filled in again, as code may be slightly - * smaller as a result. - * - * Third pass: Code generated 'for real', and branch destinations - * determined from now-accurate addrs[] map. - * - * Ideal: - * - * If we optimise this, near branches will be shorter. On the - * first assembly pass, we should err on the side of caution and - * generate the biggest code. On subsequent passes, branches will be - * generated short or long and code size will reduce. With smaller - * code, more branches may fall into the short category, and code will - * reduce more. - * - * Finally, if we see one pass generate code the same size as the - * previous pass we have converged and should now generate code for - * real. Allocating at the end will also save the memory that would - * otherwise be wasted by the (small) current code shrinkage. - * Preferably, we should do a small number of passes (e.g. 5) and if we - * haven't converged by then, get impatient and force code to generate - * as-is, even if the odd branch would be left long. The chances of a - * long jump are tiny with all but the most enormous of BPF filter - * inputs, so we should usually converge on the third pass. - */ - - cgctx.idx = 0; - cgctx.seen = 0; - cgctx.pc_ret0 = -1; - /* Scouting faux-generate pass 0 */ - if (bpf_jit_build_body(fp, 0, &cgctx, addrs)) - /* We hit something illegal or unsupported. */ - goto out; - - /* - * Pretend to build prologue, given the features we've seen. This will - * update ctgtx.idx as it pretends to output instructions, then we can - * calculate total size from idx. - */ - bpf_jit_build_prologue(fp, 0, &cgctx); - bpf_jit_build_epilogue(0, &cgctx); - - proglen = cgctx.idx * 4; - alloclen = proglen + FUNCTION_DESCR_SIZE; - image = module_alloc(alloclen); - if (!image) - goto out; - - code_base = image + (FUNCTION_DESCR_SIZE/4); - - /* Code generation passes 1-2 */ - for (pass = 1; pass < 3; pass++) { - /* Now build the prologue, body code & epilogue for real. */ - cgctx.idx = 0; - bpf_jit_build_prologue(fp, code_base, &cgctx); - bpf_jit_build_body(fp, code_base, &cgctx, addrs); - bpf_jit_build_epilogue(code_base, &cgctx); - - if (bpf_jit_enable > 1) - pr_info("Pass %d: shrink = %d, seen = 0x%x\n", pass, - proglen - (cgctx.idx * 4), cgctx.seen); - } - - if (bpf_jit_enable > 1) - /* Note that we output the base address of the code_base - * rather than image, since opcodes are in code_base. - */ - bpf_jit_dump(flen, proglen, pass, code_base); - - bpf_flush_icache(code_base, code_base + (proglen/4)); - -#ifdef CONFIG_PPC64 - /* Function descriptor nastiness: Address + TOC */ - ((u64 *)image)[0] = (u64)code_base; - ((u64 *)image)[1] = local_paca->kernel_toc; -#endif - - fp->bpf_func = (void *)image; - fp->jited = 1; - -out: - kfree(addrs); - return; -} - -void bpf_jit_free(struct bpf_prog *fp) -{ - if (fp->jited) - module_memfree(fp->bpf_func); - - bpf_prog_unlock_free(fp); -}