diff options
Diffstat (limited to 'target/linux/generic/backport-5.4')
-rw-r--r-- | target/linux/generic/backport-5.4/070-v5.5-MIPS-BPF-Restore-MIPS32-cBPF-JIT.patch | 1650 |
1 files changed, 0 insertions, 1650 deletions
diff --git a/target/linux/generic/backport-5.4/070-v5.5-MIPS-BPF-Restore-MIPS32-cBPF-JIT.patch b/target/linux/generic/backport-5.4/070-v5.5-MIPS-BPF-Restore-MIPS32-cBPF-JIT.patch deleted file mode 100644 index 027d0253a3..0000000000 --- a/target/linux/generic/backport-5.4/070-v5.5-MIPS-BPF-Restore-MIPS32-cBPF-JIT.patch +++ /dev/null @@ -1,1650 +0,0 @@ -From 36366e367ee93ced84fddb8fae6675e12985f5a4 Mon Sep 17 00:00:00 2001 -From: Paul Burton <paulburton@kernel.org> -Date: Thu, 5 Dec 2019 10:23:18 -0800 -Subject: [PATCH] MIPS: BPF: Restore MIPS32 cBPF JIT - -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 ---- - arch/mips/Kconfig | 1 + - arch/mips/net/Makefile | 1 + - arch/mips/net/bpf_jit.c | 1270 +++++++++++++++++++++++++++++++++++ - arch/mips/net/bpf_jit_asm.S | 285 ++++++++ - 4 files changed, 1557 insertions(+) - create mode 100644 arch/mips/net/bpf_jit.c - create mode 100644 arch/mips/net/bpf_jit_asm.S - ---- a/arch/mips/Kconfig -+++ b/arch/mips/Kconfig -@@ -46,6 +46,7 @@ config MIPS - select HAVE_ARCH_TRACEHOOK - select HAVE_ARCH_TRANSPARENT_HUGEPAGE if CPU_SUPPORTS_HUGEPAGES - select HAVE_ASM_MODVERSIONS -+ select HAVE_CBPF_JIT if !64BIT && !CPU_MICROMIPS - select HAVE_EBPF_JIT if 64BIT && !CPU_MICROMIPS && TARGET_ISA_REV >= 2 - select HAVE_CONTEXT_TRACKING - select HAVE_COPY_THREAD_TLS ---- a/arch/mips/net/Makefile -+++ b/arch/mips/net/Makefile -@@ -1,4 +1,5 @@ - # SPDX-License-Identifier: GPL-2.0-only - # MIPS networking code - -+obj-$(CONFIG_MIPS_CBPF_JIT) += bpf_jit.o bpf_jit_asm.o - obj-$(CONFIG_MIPS_EBPF_JIT) += ebpf_jit.o ---- /dev/null -+++ b/arch/mips/net/bpf_jit.c -@@ -0,0 +1,1270 @@ -+/* -+ * Just-In-Time compiler for BPF filters on MIPS -+ * -+ * Copyright (c) 2014 Imagination Technologies Ltd. -+ * Author: Markos Chandras <markos.chandras@imgtec.com> -+ * -+ * 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. -+ */ -+ -+#include <linux/bitops.h> -+#include <linux/compiler.h> -+#include <linux/errno.h> -+#include <linux/filter.h> -+#include <linux/if_vlan.h> -+#include <linux/moduleloader.h> -+#include <linux/netdevice.h> -+#include <linux/string.h> -+#include <linux/slab.h> -+#include <linux/types.h> -+#include <asm/asm.h> -+#include <asm/bitops.h> -+#include <asm/cacheflush.h> -+#include <asm/cpu-features.h> -+#include <asm/uasm.h> -+ -+#include "bpf_jit.h" -+ -+/* ABI -+ * r_skb_hl SKB header length -+ * r_data SKB data pointer -+ * r_off Offset -+ * r_A BPF register A -+ * r_X BPF register X -+ * r_skb *skb -+ * r_M *scratch memory -+ * r_skb_len SKB length -+ * -+ * On entry (*bpf_func)(*skb, *filter) -+ * a0 = MIPS_R_A0 = skb; -+ * a1 = MIPS_R_A1 = filter; -+ * -+ * Stack -+ * ... -+ * M[15] -+ * M[14] -+ * M[13] -+ * ... -+ * M[0] <-- r_M -+ * saved reg k-1 -+ * saved reg k-2 -+ * ... -+ * saved reg 0 <-- r_sp -+ * <no argument area> -+ * -+ * Packet layout -+ * -+ * <--------------------- len ------------------------> -+ * <--skb-len(r_skb_hl)-->< ----- skb->data_len ------> -+ * ---------------------------------------------------- -+ * | skb->data | -+ * ---------------------------------------------------- -+ */ -+ -+#define ptr typeof(unsigned long) -+ -+#define SCRATCH_OFF(k) (4 * (k)) -+ -+/* JIT flags */ -+#define SEEN_CALL (1 << BPF_MEMWORDS) -+#define SEEN_SREG_SFT (BPF_MEMWORDS + 1) -+#define SEEN_SREG_BASE (1 << SEEN_SREG_SFT) -+#define SEEN_SREG(x) (SEEN_SREG_BASE << (x)) -+#define SEEN_OFF SEEN_SREG(2) -+#define SEEN_A SEEN_SREG(3) -+#define SEEN_X SEEN_SREG(4) -+#define SEEN_SKB SEEN_SREG(5) -+#define SEEN_MEM SEEN_SREG(6) -+/* SEEN_SK_DATA also implies skb_hl an skb_len */ -+#define SEEN_SKB_DATA (SEEN_SREG(7) | SEEN_SREG(1) | SEEN_SREG(0)) -+ -+/* Arguments used by JIT */ -+#define ARGS_USED_BY_JIT 2 /* only applicable to 64-bit */ -+ -+#define SBIT(x) (1 << (x)) /* Signed version of BIT() */ -+ -+/** -+ * struct jit_ctx - JIT context -+ * @skf: The sk_filter -+ * @prologue_bytes: Number of bytes for prologue -+ * @idx: Instruction index -+ * @flags: JIT flags -+ * @offsets: Instruction offsets -+ * @target: Memory location for the compiled filter -+ */ -+struct jit_ctx { -+ const struct bpf_prog *skf; -+ unsigned int prologue_bytes; -+ u32 idx; -+ u32 flags; -+ u32 *offsets; -+ u32 *target; -+}; -+ -+ -+static inline int optimize_div(u32 *k) -+{ -+ /* power of 2 divides can be implemented with right shift */ -+ if (!(*k & (*k-1))) { -+ *k = ilog2(*k); -+ return 1; -+ } -+ -+ return 0; -+} -+ -+static inline void emit_jit_reg_move(ptr dst, ptr src, struct jit_ctx *ctx); -+ -+/* Simply emit the instruction if the JIT memory space has been allocated */ -+#define emit_instr(ctx, func, ...) \ -+do { \ -+ if ((ctx)->target != NULL) { \ -+ u32 *p = &(ctx)->target[ctx->idx]; \ -+ uasm_i_##func(&p, ##__VA_ARGS__); \ -+ } \ -+ (ctx)->idx++; \ -+} while (0) -+ -+/* -+ * Similar to emit_instr but it must be used when we need to emit -+ * 32-bit or 64-bit instructions -+ */ -+#define emit_long_instr(ctx, func, ...) \ -+do { \ -+ if ((ctx)->target != NULL) { \ -+ u32 *p = &(ctx)->target[ctx->idx]; \ -+ UASM_i_##func(&p, ##__VA_ARGS__); \ -+ } \ -+ (ctx)->idx++; \ -+} while (0) -+ -+/* Determine if immediate is within the 16-bit signed range */ -+static inline bool is_range16(s32 imm) -+{ -+ return !(imm >= SBIT(15) || imm < -SBIT(15)); -+} -+ -+static inline void emit_addu(unsigned int dst, unsigned int src1, -+ unsigned int src2, struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, addu, dst, src1, src2); -+} -+ -+static inline void emit_nop(struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, nop); -+} -+ -+/* Load a u32 immediate to a register */ -+static inline void emit_load_imm(unsigned int dst, u32 imm, struct jit_ctx *ctx) -+{ -+ if (ctx->target != NULL) { -+ /* addiu can only handle s16 */ -+ if (!is_range16(imm)) { -+ u32 *p = &ctx->target[ctx->idx]; -+ uasm_i_lui(&p, r_tmp_imm, (s32)imm >> 16); -+ p = &ctx->target[ctx->idx + 1]; -+ uasm_i_ori(&p, dst, r_tmp_imm, imm & 0xffff); -+ } else { -+ u32 *p = &ctx->target[ctx->idx]; -+ uasm_i_addiu(&p, dst, r_zero, imm); -+ } -+ } -+ ctx->idx++; -+ -+ if (!is_range16(imm)) -+ ctx->idx++; -+} -+ -+static inline void emit_or(unsigned int dst, unsigned int src1, -+ unsigned int src2, struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, or, dst, src1, src2); -+} -+ -+static inline void emit_ori(unsigned int dst, unsigned src, u32 imm, -+ struct jit_ctx *ctx) -+{ -+ if (imm >= BIT(16)) { -+ emit_load_imm(r_tmp, imm, ctx); -+ emit_or(dst, src, r_tmp, ctx); -+ } else { -+ emit_instr(ctx, ori, dst, src, imm); -+ } -+} -+ -+static inline void emit_daddiu(unsigned int dst, unsigned int src, -+ int imm, struct jit_ctx *ctx) -+{ -+ /* -+ * Only used for stack, so the imm is relatively small -+ * and it fits in 15-bits -+ */ -+ emit_instr(ctx, daddiu, dst, src, imm); -+} -+ -+static inline void emit_addiu(unsigned int dst, unsigned int src, -+ u32 imm, struct jit_ctx *ctx) -+{ -+ if (!is_range16(imm)) { -+ emit_load_imm(r_tmp, imm, ctx); -+ emit_addu(dst, r_tmp, src, ctx); -+ } else { -+ emit_instr(ctx, addiu, dst, src, imm); -+ } -+} -+ -+static inline void emit_and(unsigned int dst, unsigned int src1, -+ unsigned int src2, struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, and, dst, src1, src2); -+} -+ -+static inline void emit_andi(unsigned int dst, unsigned int src, -+ u32 imm, struct jit_ctx *ctx) -+{ -+ /* If imm does not fit in u16 then load it to register */ -+ if (imm >= BIT(16)) { -+ emit_load_imm(r_tmp, imm, ctx); -+ emit_and(dst, src, r_tmp, ctx); -+ } else { -+ emit_instr(ctx, andi, dst, src, imm); -+ } -+} -+ -+static inline void emit_xor(unsigned int dst, unsigned int src1, -+ unsigned int src2, struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, xor, dst, src1, src2); -+} -+ -+static inline void emit_xori(ptr dst, ptr src, u32 imm, struct jit_ctx *ctx) -+{ -+ /* If imm does not fit in u16 then load it to register */ -+ if (imm >= BIT(16)) { -+ emit_load_imm(r_tmp, imm, ctx); -+ emit_xor(dst, src, r_tmp, ctx); -+ } else { -+ emit_instr(ctx, xori, dst, src, imm); -+ } -+} -+ -+static inline void emit_stack_offset(int offset, struct jit_ctx *ctx) -+{ -+ emit_long_instr(ctx, ADDIU, r_sp, r_sp, offset); -+} -+ -+static inline void emit_subu(unsigned int dst, unsigned int src1, -+ unsigned int src2, struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, subu, dst, src1, src2); -+} -+ -+static inline void emit_neg(unsigned int reg, struct jit_ctx *ctx) -+{ -+ emit_subu(reg, r_zero, reg, ctx); -+} -+ -+static inline void emit_sllv(unsigned int dst, unsigned int src, -+ unsigned int sa, struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, sllv, dst, src, sa); -+} -+ -+static inline void emit_sll(unsigned int dst, unsigned int src, -+ unsigned int sa, struct jit_ctx *ctx) -+{ -+ /* sa is 5-bits long */ -+ if (sa >= BIT(5)) -+ /* Shifting >= 32 results in zero */ -+ emit_jit_reg_move(dst, r_zero, ctx); -+ else -+ emit_instr(ctx, sll, dst, src, sa); -+} -+ -+static inline void emit_srlv(unsigned int dst, unsigned int src, -+ unsigned int sa, struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, srlv, dst, src, sa); -+} -+ -+static inline void emit_srl(unsigned int dst, unsigned int src, -+ unsigned int sa, struct jit_ctx *ctx) -+{ -+ /* sa is 5-bits long */ -+ if (sa >= BIT(5)) -+ /* Shifting >= 32 results in zero */ -+ emit_jit_reg_move(dst, r_zero, ctx); -+ else -+ emit_instr(ctx, srl, dst, src, sa); -+} -+ -+static inline void emit_slt(unsigned int dst, unsigned int src1, -+ unsigned int src2, struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, slt, dst, src1, src2); -+} -+ -+static inline void emit_sltu(unsigned int dst, unsigned int src1, -+ unsigned int src2, struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, sltu, dst, src1, src2); -+} -+ -+static inline void emit_sltiu(unsigned dst, unsigned int src, -+ unsigned int imm, struct jit_ctx *ctx) -+{ -+ /* 16 bit immediate */ -+ if (!is_range16((s32)imm)) { -+ emit_load_imm(r_tmp, imm, ctx); -+ emit_sltu(dst, src, r_tmp, ctx); -+ } else { -+ emit_instr(ctx, sltiu, dst, src, imm); -+ } -+ -+} -+ -+/* Store register on the stack */ -+static inline void emit_store_stack_reg(ptr reg, ptr base, -+ unsigned int offset, -+ struct jit_ctx *ctx) -+{ -+ emit_long_instr(ctx, SW, reg, offset, base); -+} -+ -+static inline void emit_store(ptr reg, ptr base, unsigned int offset, -+ struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, sw, reg, offset, base); -+} -+ -+static inline void emit_load_stack_reg(ptr reg, ptr base, -+ unsigned int offset, -+ struct jit_ctx *ctx) -+{ -+ emit_long_instr(ctx, LW, reg, offset, base); -+} -+ -+static inline void emit_load(unsigned int reg, unsigned int base, -+ unsigned int offset, struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, lw, reg, offset, base); -+} -+ -+static inline void emit_load_byte(unsigned int reg, unsigned int base, -+ unsigned int offset, struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, lb, reg, offset, base); -+} -+ -+static inline void emit_half_load(unsigned int reg, unsigned int base, -+ unsigned int offset, struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, lh, reg, offset, base); -+} -+ -+static inline void emit_half_load_unsigned(unsigned int reg, unsigned int base, -+ unsigned int offset, struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, lhu, reg, offset, base); -+} -+ -+static inline void emit_mul(unsigned int dst, unsigned int src1, -+ unsigned int src2, struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, mul, dst, src1, src2); -+} -+ -+static inline void emit_div(unsigned int dst, unsigned int src, -+ struct jit_ctx *ctx) -+{ -+ if (ctx->target != NULL) { -+ u32 *p = &ctx->target[ctx->idx]; -+ uasm_i_divu(&p, dst, src); -+ p = &ctx->target[ctx->idx + 1]; -+ uasm_i_mflo(&p, dst); -+ } -+ ctx->idx += 2; /* 2 insts */ -+} -+ -+static inline void emit_mod(unsigned int dst, unsigned int src, -+ struct jit_ctx *ctx) -+{ -+ if (ctx->target != NULL) { -+ u32 *p = &ctx->target[ctx->idx]; -+ uasm_i_divu(&p, dst, src); -+ p = &ctx->target[ctx->idx + 1]; -+ uasm_i_mfhi(&p, dst); -+ } -+ ctx->idx += 2; /* 2 insts */ -+} -+ -+static inline void emit_dsll(unsigned int dst, unsigned int src, -+ unsigned int sa, struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, dsll, dst, src, sa); -+} -+ -+static inline void emit_dsrl32(unsigned int dst, unsigned int src, -+ unsigned int sa, struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, dsrl32, dst, src, sa); -+} -+ -+static inline void emit_wsbh(unsigned int dst, unsigned int src, -+ struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, wsbh, dst, src); -+} -+ -+/* load pointer to register */ -+static inline void emit_load_ptr(unsigned int dst, unsigned int src, -+ int imm, struct jit_ctx *ctx) -+{ -+ /* src contains the base addr of the 32/64-pointer */ -+ emit_long_instr(ctx, LW, dst, imm, src); -+} -+ -+/* load a function pointer to register */ -+static inline void emit_load_func(unsigned int reg, ptr imm, -+ struct jit_ctx *ctx) -+{ -+ if (IS_ENABLED(CONFIG_64BIT)) { -+ /* At this point imm is always 64-bit */ -+ emit_load_imm(r_tmp, (u64)imm >> 32, ctx); -+ emit_dsll(r_tmp_imm, r_tmp, 16, ctx); /* left shift by 16 */ -+ emit_ori(r_tmp, r_tmp_imm, (imm >> 16) & 0xffff, ctx); -+ emit_dsll(r_tmp_imm, r_tmp, 16, ctx); /* left shift by 16 */ -+ emit_ori(reg, r_tmp_imm, imm & 0xffff, ctx); -+ } else { -+ emit_load_imm(reg, imm, ctx); -+ } -+} -+ -+/* Move to real MIPS register */ -+static inline void emit_reg_move(ptr dst, ptr src, struct jit_ctx *ctx) -+{ -+ emit_long_instr(ctx, ADDU, dst, src, r_zero); -+} -+ -+/* Move to JIT (32-bit) register */ -+static inline void emit_jit_reg_move(ptr dst, ptr src, struct jit_ctx *ctx) -+{ -+ emit_addu(dst, src, r_zero, ctx); -+} -+ -+/* Compute the immediate value for PC-relative branches. */ -+static inline u32 b_imm(unsigned int tgt, struct jit_ctx *ctx) -+{ -+ if (ctx->target == NULL) -+ return 0; -+ -+ /* -+ * We want a pc-relative branch. We only do forward branches -+ * so tgt is always after pc. tgt is the instruction offset -+ * we want to jump to. -+ -+ * Branch on MIPS: -+ * I: target_offset <- sign_extend(offset) -+ * I+1: PC += target_offset (delay slot) -+ * -+ * ctx->idx currently points to the branch instruction -+ * but the offset is added to the delay slot so we need -+ * to subtract 4. -+ */ -+ return ctx->offsets[tgt] - -+ (ctx->idx * 4 - ctx->prologue_bytes) - 4; -+} -+ -+static inline void emit_bcond(int cond, unsigned int reg1, unsigned int reg2, -+ unsigned int imm, struct jit_ctx *ctx) -+{ -+ if (ctx->target != NULL) { -+ u32 *p = &ctx->target[ctx->idx]; -+ -+ switch (cond) { -+ case MIPS_COND_EQ: -+ uasm_i_beq(&p, reg1, reg2, imm); -+ break; -+ case MIPS_COND_NE: -+ uasm_i_bne(&p, reg1, reg2, imm); -+ break; -+ case MIPS_COND_ALL: -+ uasm_i_b(&p, imm); -+ break; -+ default: -+ pr_warn("%s: Unhandled branch conditional: %d\n", -+ __func__, cond); -+ } -+ } -+ ctx->idx++; -+} -+ -+static inline void emit_b(unsigned int imm, struct jit_ctx *ctx) -+{ -+ emit_bcond(MIPS_COND_ALL, r_zero, r_zero, imm, ctx); -+} -+ -+static inline void emit_jalr(unsigned int link, unsigned int reg, -+ struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, jalr, link, reg); -+} -+ -+static inline void emit_jr(unsigned int reg, struct jit_ctx *ctx) -+{ -+ emit_instr(ctx, jr, reg); -+} -+ -+static inline u16 align_sp(unsigned int num) -+{ -+ /* Double word alignment for 32-bit, quadword for 64-bit */ -+ unsigned int align = IS_ENABLED(CONFIG_64BIT) ? 16 : 8; -+ num = (num + (align - 1)) & -align; -+ return num; -+} -+ -+static void save_bpf_jit_regs(struct jit_ctx *ctx, unsigned offset) -+{ -+ int i = 0, real_off = 0; -+ u32 sflags, tmp_flags; -+ -+ /* Adjust the stack pointer */ -+ if (offset) -+ emit_stack_offset(-align_sp(offset), ctx); -+ -+ tmp_flags = sflags = ctx->flags >> SEEN_SREG_SFT; -+ /* sflags is essentially a bitmap */ -+ while (tmp_flags) { -+ if ((sflags >> i) & 0x1) { -+ emit_store_stack_reg(MIPS_R_S0 + i, r_sp, real_off, -+ ctx); -+ real_off += SZREG; -+ } -+ i++; -+ tmp_flags >>= 1; -+ } -+ -+ /* save return address */ -+ if (ctx->flags & SEEN_CALL) { -+ emit_store_stack_reg(r_ra, r_sp, real_off, ctx); -+ real_off += SZREG; -+ } -+ -+ /* Setup r_M leaving the alignment gap if necessary */ -+ if (ctx->flags & SEEN_MEM) { -+ if (real_off % (SZREG * 2)) -+ real_off += SZREG; -+ emit_long_instr(ctx, ADDIU, r_M, r_sp, real_off); -+ } -+} -+ -+static void restore_bpf_jit_regs(struct jit_ctx *ctx, -+ unsigned int offset) -+{ -+ int i, real_off = 0; -+ u32 sflags, tmp_flags; -+ -+ tmp_flags = sflags = ctx->flags >> SEEN_SREG_SFT; -+ /* sflags is a bitmap */ -+ i = 0; -+ while (tmp_flags) { -+ if ((sflags >> i) & 0x1) { -+ emit_load_stack_reg(MIPS_R_S0 + i, r_sp, real_off, -+ ctx); -+ real_off += SZREG; -+ } -+ i++; -+ tmp_flags >>= 1; -+ } -+ -+ /* restore return address */ -+ if (ctx->flags & SEEN_CALL) -+ emit_load_stack_reg(r_ra, r_sp, real_off, ctx); -+ -+ /* Restore the sp and discard the scrach memory */ -+ if (offset) -+ emit_stack_offset(align_sp(offset), ctx); -+} -+ -+static unsigned int get_stack_depth(struct jit_ctx *ctx) -+{ -+ int sp_off = 0; -+ -+ -+ /* How may s* regs do we need to preserved? */ -+ sp_off += hweight32(ctx->flags >> SEEN_SREG_SFT) * SZREG; -+ -+ if (ctx->flags & SEEN_MEM) -+ sp_off += 4 * BPF_MEMWORDS; /* BPF_MEMWORDS are 32-bit */ -+ -+ if (ctx->flags & SEEN_CALL) -+ sp_off += SZREG; /* Space for our ra register */ -+ -+ return sp_off; -+} -+ -+static void build_prologue(struct jit_ctx *ctx) -+{ -+ int sp_off; -+ -+ /* Calculate the total offset for the stack pointer */ -+ sp_off = get_stack_depth(ctx); -+ save_bpf_jit_regs(ctx, sp_off); -+ -+ if (ctx->flags & SEEN_SKB) -+ emit_reg_move(r_skb, MIPS_R_A0, ctx); -+ -+ if (ctx->flags & SEEN_SKB_DATA) { -+ /* Load packet length */ -+ emit_load(r_skb_len, r_skb, offsetof(struct sk_buff, len), -+ ctx); -+ emit_load(r_tmp, r_skb, offsetof(struct sk_buff, data_len), -+ ctx); -+ /* Load the data pointer */ -+ emit_load_ptr(r_skb_data, r_skb, -+ offsetof(struct sk_buff, data), ctx); -+ /* Load the header length */ -+ emit_subu(r_skb_hl, r_skb_len, r_tmp, ctx); -+ } -+ -+ if (ctx->flags & SEEN_X) -+ emit_jit_reg_move(r_X, r_zero, ctx); -+ -+ /* -+ * Do not leak kernel data to userspace, we only need to clear -+ * r_A if it is ever used. In fact if it is never used, we -+ * will not save/restore it, so clearing it in this case would -+ * corrupt the state of the caller. -+ */ -+ if (bpf_needs_clear_a(&ctx->skf->insns[0]) && -+ (ctx->flags & SEEN_A)) -+ emit_jit_reg_move(r_A, r_zero, ctx); -+} -+ -+static void build_epilogue(struct jit_ctx *ctx) -+{ -+ unsigned int sp_off; -+ -+ /* Calculate the total offset for the stack pointer */ -+ -+ sp_off = get_stack_depth(ctx); -+ restore_bpf_jit_regs(ctx, sp_off); -+ -+ /* Return */ -+ emit_jr(r_ra, ctx); -+ emit_nop(ctx); -+} -+ -+#define CHOOSE_LOAD_FUNC(K, func) \ -+ ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative : func) : \ -+ func##_positive) -+ -+static int build_body(struct jit_ctx *ctx) -+{ -+ const struct bpf_prog *prog = ctx->skf; -+ const struct sock_filter *inst; -+ unsigned int i, off, condt; -+ u32 k, b_off __maybe_unused; -+ u8 (*sk_load_func)(unsigned long *skb, int offset); -+ -+ for (i = 0; i < prog->len; i++) { -+ u16 code; -+ -+ inst = &(prog->insns[i]); -+ pr_debug("%s: code->0x%02x, jt->0x%x, jf->0x%x, k->0x%x\n", -+ __func__, inst->code, inst->jt, inst->jf, inst->k); -+ k = inst->k; -+ code = bpf_anc_helper(inst); -+ -+ if (ctx->target == NULL) -+ ctx->offsets[i] = ctx->idx * 4; -+ -+ switch (code) { -+ case BPF_LD | BPF_IMM: -+ /* A <- k ==> li r_A, k */ -+ ctx->flags |= SEEN_A; -+ emit_load_imm(r_A, k, ctx); -+ break; -+ case BPF_LD | BPF_W | BPF_LEN: -+ BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4); -+ /* A <- len ==> lw r_A, offset(skb) */ -+ ctx->flags |= SEEN_SKB | SEEN_A; -+ off = offsetof(struct sk_buff, len); -+ emit_load(r_A, r_skb, off, ctx); -+ break; -+ case BPF_LD | BPF_MEM: -+ /* A <- M[k] ==> lw r_A, offset(M) */ -+ ctx->flags |= SEEN_MEM | SEEN_A; -+ emit_load(r_A, r_M, SCRATCH_OFF(k), ctx); -+ break; -+ case BPF_LD | BPF_W | BPF_ABS: -+ /* A <- P[k:4] */ -+ sk_load_func = CHOOSE_LOAD_FUNC(k, sk_load_word); -+ goto load; -+ case BPF_LD | BPF_H | BPF_ABS: -+ /* A <- P[k:2] */ -+ sk_load_func = CHOOSE_LOAD_FUNC(k, sk_load_half); -+ goto load; -+ case BPF_LD | BPF_B | BPF_ABS: -+ /* A <- P[k:1] */ -+ sk_load_func = CHOOSE_LOAD_FUNC(k, sk_load_byte); -+load: -+ emit_load_imm(r_off, k, ctx); -+load_common: -+ ctx->flags |= SEEN_CALL | SEEN_OFF | -+ SEEN_SKB | SEEN_A | SEEN_SKB_DATA; -+ -+ emit_load_func(r_s0, (ptr)sk_load_func, ctx); -+ emit_reg_move(MIPS_R_A0, r_skb, ctx); -+ emit_jalr(MIPS_R_RA, r_s0, ctx); -+ /* Load second argument to delay slot */ -+ emit_reg_move(MIPS_R_A1, r_off, ctx); -+ /* Check the error value */ -+ emit_bcond(MIPS_COND_EQ, r_ret, 0, b_imm(i + 1, ctx), -+ ctx); -+ /* Load return register on DS for failures */ -+ emit_reg_move(r_ret, r_zero, ctx); -+ /* Return with error */ -+ emit_b(b_imm(prog->len, ctx), ctx); -+ emit_nop(ctx); -+ break; -+ case BPF_LD | BPF_W | BPF_IND: -+ /* A <- P[X + k:4] */ -+ sk_load_func = sk_load_word; -+ goto load_ind; -+ case BPF_LD | BPF_H | BPF_IND: -+ /* A <- P[X + k:2] */ -+ sk_load_func = sk_load_half; -+ goto load_ind; -+ case BPF_LD | BPF_B | BPF_IND: -+ /* A <- P[X + k:1] */ -+ sk_load_func = sk_load_byte; -+load_ind: -+ ctx->flags |= SEEN_OFF | SEEN_X; -+ emit_addiu(r_off, r_X, k, ctx); -+ goto load_common; -+ case BPF_LDX | BPF_IMM: -+ /* X <- k */ -+ ctx->flags |= SEEN_X; -+ emit_load_imm(r_X, k, ctx); -+ break; -+ case BPF_LDX | BPF_MEM: -+ /* X <- M[k] */ -+ ctx->flags |= SEEN_X | SEEN_MEM; -+ emit_load(r_X, r_M, SCRATCH_OFF(k), ctx); -+ break; -+ case BPF_LDX | BPF_W | BPF_LEN: -+ /* X <- len */ -+ ctx->flags |= SEEN_X | SEEN_SKB; -+ off = offsetof(struct sk_buff, len); -+ emit_load(r_X, r_skb, off, ctx); -+ break; -+ case BPF_LDX | BPF_B | BPF_MSH: -+ /* X <- 4 * (P[k:1] & 0xf) */ -+ ctx->flags |= SEEN_X | SEEN_CALL | SEEN_SKB; -+ /* Load offset to a1 */ -+ emit_load_func(r_s0, (ptr)sk_load_byte, ctx); -+ /* -+ * This may emit two instructions so it may not fit -+ * in the delay slot. So use a0 in the delay slot. -+ */ -+ emit_load_imm(MIPS_R_A1, k, ctx); -+ emit_jalr(MIPS_R_RA, r_s0, ctx); -+ emit_reg_move(MIPS_R_A0, r_skb, ctx); /* delay slot */ -+ /* Check the error value */ -+ emit_bcond(MIPS_COND_NE, r_ret, 0, -+ b_imm(prog->len, ctx), ctx); -+ emit_reg_move(r_ret, r_zero, ctx); -+ /* We are good */ -+ /* X <- P[1:K] & 0xf */ -+ emit_andi(r_X, r_A, 0xf, ctx); -+ /* X << 2 */ -+ emit_b(b_imm(i + 1, ctx), ctx); -+ emit_sll(r_X, r_X, 2, ctx); /* delay slot */ -+ break; -+ case BPF_ST: -+ /* M[k] <- A */ -+ ctx->flags |= SEEN_MEM | SEEN_A; -+ emit_store(r_A, r_M, SCRATCH_OFF(k), ctx); -+ break; -+ case BPF_STX: -+ /* M[k] <- X */ -+ ctx->flags |= SEEN_MEM | SEEN_X; -+ emit_store(r_X, r_M, SCRATCH_OFF(k), ctx); -+ break; -+ case BPF_ALU | BPF_ADD | BPF_K: -+ /* A += K */ -+ ctx->flags |= SEEN_A; -+ emit_addiu(r_A, r_A, k, ctx); -+ break; -+ case BPF_ALU | BPF_ADD | BPF_X: -+ /* A += X */ -+ ctx->flags |= SEEN_A | SEEN_X; -+ emit_addu(r_A, r_A, r_X, ctx); -+ break; -+ case BPF_ALU | BPF_SUB | BPF_K: -+ /* A -= K */ -+ ctx->flags |= SEEN_A; -+ emit_addiu(r_A, r_A, -k, ctx); -+ break; -+ case BPF_ALU | BPF_SUB | BPF_X: -+ /* A -= X */ -+ ctx->flags |= SEEN_A | SEEN_X; -+ emit_subu(r_A, r_A, r_X, ctx); -+ break; -+ case BPF_ALU | BPF_MUL | BPF_K: -+ /* A *= K */ -+ /* Load K to scratch register before MUL */ -+ ctx->flags |= SEEN_A; -+ emit_load_imm(r_s0, k, ctx); -+ emit_mul(r_A, r_A, r_s0, ctx); -+ break; -+ case BPF_ALU | BPF_MUL | BPF_X: -+ /* A *= X */ -+ ctx->flags |= SEEN_A | SEEN_X; -+ emit_mul(r_A, r_A, r_X, ctx); -+ break; -+ case BPF_ALU | BPF_DIV | BPF_K: -+ /* A /= k */ -+ if (k == 1) -+ break; -+ if (optimize_div(&k)) { -+ ctx->flags |= SEEN_A; -+ emit_srl(r_A, r_A, k, ctx); -+ break; -+ } -+ ctx->flags |= SEEN_A; -+ emit_load_imm(r_s0, k, ctx); -+ emit_div(r_A, r_s0, ctx); -+ break; -+ case BPF_ALU | BPF_MOD | BPF_K: -+ /* A %= k */ -+ if (k == 1) { -+ ctx->flags |= SEEN_A; -+ emit_jit_reg_move(r_A, r_zero, ctx); -+ } else { -+ ctx->flags |= SEEN_A; -+ emit_load_imm(r_s0, k, ctx); -+ emit_mod(r_A, r_s0, ctx); -+ } -+ break; -+ case BPF_ALU | BPF_DIV | BPF_X: -+ /* A /= X */ -+ ctx->flags |= SEEN_X | SEEN_A; -+ /* Check if r_X is zero */ -+ emit_bcond(MIPS_COND_EQ, r_X, r_zero, -+ b_imm(prog->len, ctx), ctx); -+ emit_load_imm(r_ret, 0, ctx); /* delay slot */ -+ emit_div(r_A, r_X, ctx); -+ break; -+ case BPF_ALU | BPF_MOD | BPF_X: -+ /* A %= X */ -+ ctx->flags |= SEEN_X | SEEN_A; -+ /* Check if r_X is zero */ -+ emit_bcond(MIPS_COND_EQ, r_X, r_zero, -+ b_imm(prog->len, ctx), ctx); -+ emit_load_imm(r_ret, 0, ctx); /* delay slot */ -+ emit_mod(r_A, r_X, ctx); -+ break; -+ case BPF_ALU | BPF_OR | BPF_K: -+ /* A |= K */ -+ ctx->flags |= SEEN_A; -+ emit_ori(r_A, r_A, k, ctx); -+ break; -+ case BPF_ALU | BPF_OR | BPF_X: -+ /* A |= X */ -+ ctx->flags |= SEEN_A; -+ emit_ori(r_A, r_A, r_X, ctx); -+ break; -+ case BPF_ALU | BPF_XOR | BPF_K: -+ /* A ^= k */ -+ ctx->flags |= SEEN_A; -+ emit_xori(r_A, r_A, k, ctx); -+ break; -+ case BPF_ANC | SKF_AD_ALU_XOR_X: -+ case BPF_ALU | BPF_XOR | BPF_X: -+ /* A ^= X */ -+ ctx->flags |= SEEN_A; -+ emit_xor(r_A, r_A, r_X, ctx); -+ break; -+ case BPF_ALU | BPF_AND | BPF_K: -+ /* A &= K */ -+ ctx->flags |= SEEN_A; -+ emit_andi(r_A, r_A, k, ctx); -+ break; -+ case BPF_ALU | BPF_AND | BPF_X: -+ /* A &= X */ -+ ctx->flags |= SEEN_A | SEEN_X; -+ emit_and(r_A, r_A, r_X, ctx); -+ break; -+ case BPF_ALU | BPF_LSH | BPF_K: -+ /* A <<= K */ -+ ctx->flags |= SEEN_A; -+ emit_sll(r_A, r_A, k, ctx); -+ break; -+ case BPF_ALU | BPF_LSH | BPF_X: -+ /* A <<= X */ -+ ctx->flags |= SEEN_A | SEEN_X; -+ emit_sllv(r_A, r_A, r_X, ctx); -+ break; -+ case BPF_ALU | BPF_RSH | BPF_K: -+ /* A >>= K */ -+ ctx->flags |= SEEN_A; -+ emit_srl(r_A, r_A, k, ctx); -+ break; -+ case BPF_ALU | BPF_RSH | BPF_X: -+ ctx->flags |= SEEN_A | SEEN_X; -+ emit_srlv(r_A, r_A, r_X, ctx); -+ break; -+ case BPF_ALU | BPF_NEG: -+ /* A = -A */ -+ ctx->flags |= SEEN_A; -+ emit_neg(r_A, ctx); -+ break; -+ case BPF_JMP | BPF_JA: -+ /* pc += K */ -+ emit_b(b_imm(i + k + 1, ctx), ctx); -+ emit_nop(ctx); -+ break; -+ case BPF_JMP | BPF_JEQ | BPF_K: -+ /* pc += ( A == K ) ? pc->jt : pc->jf */ -+ condt = MIPS_COND_EQ | MIPS_COND_K; -+ goto jmp_cmp; -+ case BPF_JMP | BPF_JEQ | BPF_X: -+ ctx->flags |= SEEN_X; -+ /* pc += ( A == X ) ? pc->jt : pc->jf */ -+ condt = MIPS_COND_EQ | MIPS_COND_X; -+ goto jmp_cmp; -+ case BPF_JMP | BPF_JGE | BPF_K: -+ /* pc += ( A >= K ) ? pc->jt : pc->jf */ -+ condt = MIPS_COND_GE | MIPS_COND_K; -+ goto jmp_cmp; -+ case BPF_JMP | BPF_JGE | BPF_X: -+ ctx->flags |= SEEN_X; -+ /* pc += ( A >= X ) ? pc->jt : pc->jf */ -+ condt = MIPS_COND_GE | MIPS_COND_X; -+ goto jmp_cmp; -+ case BPF_JMP | BPF_JGT | BPF_K: -+ /* pc += ( A > K ) ? pc->jt : pc->jf */ -+ condt = MIPS_COND_GT | MIPS_COND_K; -+ goto jmp_cmp; -+ case BPF_JMP | BPF_JGT | BPF_X: -+ ctx->flags |= SEEN_X; -+ /* pc += ( A > X ) ? pc->jt : pc->jf */ -+ condt = MIPS_COND_GT | MIPS_COND_X; -+jmp_cmp: -+ /* Greater or Equal */ -+ if ((condt & MIPS_COND_GE) || -+ (condt & MIPS_COND_GT)) { -+ if (condt & MIPS_COND_K) { /* K */ -+ ctx->flags |= SEEN_A; -+ emit_sltiu(r_s0, r_A, k, ctx); -+ } else { /* X */ -+ ctx->flags |= SEEN_A | -+ SEEN_X; -+ emit_sltu(r_s0, r_A, r_X, ctx); -+ } -+ /* A < (K|X) ? r_scrach = 1 */ -+ b_off = b_imm(i + inst->jf + 1, ctx); -+ emit_bcond(MIPS_COND_NE, r_s0, r_zero, b_off, -+ ctx); -+ emit_nop(ctx); -+ /* A > (K|X) ? scratch = 0 */ -+ if (condt & MIPS_COND_GT) { -+ /* Checking for equality */ -+ ctx->flags |= SEEN_A | SEEN_X; -+ if (condt & MIPS_COND_K) -+ emit_load_imm(r_s0, k, ctx); -+ else -+ emit_jit_reg_move(r_s0, r_X, -+ ctx); -+ b_off = b_imm(i + inst->jf + 1, ctx); -+ emit_bcond(MIPS_COND_EQ, r_A, r_s0, -+ b_off, ctx); -+ emit_nop(ctx); -+ /* Finally, A > K|X */ -+ b_off = b_imm(i + inst->jt + 1, ctx); -+ emit_b(b_off, ctx); -+ emit_nop(ctx); -+ } else { -+ /* A >= (K|X) so jump */ -+ b_off = b_imm(i + inst->jt + 1, ctx); -+ emit_b(b_off, ctx); -+ emit_nop(ctx); -+ } -+ } else { -+ /* A == K|X */ -+ if (condt & MIPS_COND_K) { /* K */ -+ ctx->flags |= SEEN_A; -+ emit_load_imm(r_s0, k, ctx); -+ /* jump true */ -+ b_off = b_imm(i + inst->jt + 1, ctx); -+ emit_bcond(MIPS_COND_EQ, r_A, r_s0, -+ b_off, ctx); -+ emit_nop(ctx); -+ /* jump false */ -+ b_off = b_imm(i + inst->jf + 1, -+ ctx); -+ emit_bcond(MIPS_COND_NE, r_A, r_s0, -+ b_off, ctx); -+ emit_nop(ctx); -+ } else { /* X */ -+ /* jump true */ -+ ctx->flags |= SEEN_A | SEEN_X; -+ b_off = b_imm(i + inst->jt + 1, -+ ctx); -+ emit_bcond(MIPS_COND_EQ, r_A, r_X, -+ b_off, ctx); -+ emit_nop(ctx); -+ /* jump false */ -+ b_off = b_imm(i + inst->jf + 1, ctx); -+ emit_bcond(MIPS_COND_NE, r_A, r_X, -+ b_off, ctx); -+ emit_nop(ctx); -+ } -+ } -+ break; -+ case BPF_JMP | BPF_JSET | BPF_K: -+ ctx->flags |= SEEN_A; -+ /* pc += (A & K) ? pc -> jt : pc -> jf */ -+ emit_load_imm(r_s1, k, ctx); -+ emit_and(r_s0, r_A, r_s1, ctx); -+ /* jump true */ -+ b_off = b_imm(i + inst->jt + 1, ctx); -+ emit_bcond(MIPS_COND_NE, r_s0, r_zero, b_off, ctx); -+ emit_nop(ctx); -+ /* jump false */ -+ b_off = b_imm(i + inst->jf + 1, ctx); -+ emit_b(b_off, ctx); -+ emit_nop(ctx); -+ break; -+ case BPF_JMP | BPF_JSET | BPF_X: -+ ctx->flags |= SEEN_X | SEEN_A; -+ /* pc += (A & X) ? pc -> jt : pc -> jf */ -+ emit_and(r_s0, r_A, r_X, ctx); -+ /* jump true */ -+ b_off = b_imm(i + inst->jt + 1, ctx); -+ emit_bcond(MIPS_COND_NE, r_s0, r_zero, b_off, ctx); -+ emit_nop(ctx); -+ /* jump false */ -+ b_off = b_imm(i + inst->jf + 1, ctx); -+ emit_b(b_off, ctx); -+ emit_nop(ctx); -+ break; -+ case BPF_RET | BPF_A: -+ ctx->flags |= SEEN_A; -+ if (i != prog->len - 1) -+ /* -+ * If this is not the last instruction -+ * then jump to the epilogue -+ */ -+ emit_b(b_imm(prog->len, ctx), ctx); -+ emit_reg_move(r_ret, r_A, ctx); /* delay slot */ -+ break; -+ case BPF_RET | BPF_K: -+ /* -+ * It can emit two instructions so it does not fit on -+ * the delay slot. -+ */ -+ emit_load_imm(r_ret, k, ctx); -+ if (i != prog->len - 1) { -+ /* -+ * If this is not the last instruction -+ * then jump to the epilogue -+ */ -+ emit_b(b_imm(prog->len, ctx), ctx); -+ emit_nop(ctx); -+ } -+ break; -+ case BPF_MISC | BPF_TAX: -+ /* X = A */ -+ ctx->flags |= SEEN_X | SEEN_A; -+ emit_jit_reg_move(r_X, r_A, ctx); -+ break; -+ case BPF_MISC | BPF_TXA: -+ /* A = X */ -+ ctx->flags |= SEEN_A | SEEN_X; -+ emit_jit_reg_move(r_A, r_X, ctx); -+ break; -+ /* AUX */ -+ case BPF_ANC | SKF_AD_PROTOCOL: -+ /* A = ntohs(skb->protocol */ -+ ctx->flags |= SEEN_SKB | SEEN_OFF | SEEN_A; -+ BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, -+ protocol) != 2); -+ off = offsetof(struct sk_buff, protocol); -+ emit_half_load(r_A, r_skb, off, ctx); -+#ifdef CONFIG_CPU_LITTLE_ENDIAN -+ /* This needs little endian fixup */ -+ if (cpu_has_wsbh) { -+ /* R2 and later have the wsbh instruction */ -+ emit_wsbh(r_A, r_A, ctx); -+ } else { -+ /* Get first byte */ -+ emit_andi(r_tmp_imm, r_A, 0xff, ctx); -+ /* Shift it */ -+ emit_sll(r_tmp, r_tmp_imm, 8, ctx); -+ /* Get second byte */ -+ emit_srl(r_tmp_imm, r_A, 8, ctx); -+ emit_andi(r_tmp_imm, r_tmp_imm, 0xff, ctx); -+ /* Put everyting together in r_A */ -+ emit_or(r_A, r_tmp, r_tmp_imm, ctx); -+ } -+#endif -+ break; -+ case BPF_ANC | SKF_AD_CPU: -+ ctx->flags |= SEEN_A | SEEN_OFF; -+ /* A = current_thread_info()->cpu */ -+ BUILD_BUG_ON(FIELD_SIZEOF(struct thread_info, -+ cpu) != 4); -+ off = offsetof(struct thread_info, cpu); -+ /* $28/gp points to the thread_info struct */ -+ emit_load(r_A, 28, off, ctx); -+ break; -+ case BPF_ANC | SKF_AD_IFINDEX: -+ /* A = skb->dev->ifindex */ -+ case BPF_ANC | SKF_AD_HATYPE: -+ /* A = skb->dev->type */ -+ ctx->flags |= SEEN_SKB | SEEN_A; -+ off = offsetof(struct sk_buff, dev); -+ /* Load *dev pointer */ -+ emit_load_ptr(r_s0, r_skb, off, ctx); -+ /* error (0) in the delay slot */ -+ emit_bcond(MIPS_COND_EQ, r_s0, r_zero, -+ b_imm(prog->len, ctx), ctx); -+ emit_reg_move(r_ret, r_zero, ctx); -+ if (code == (BPF_ANC | SKF_AD_IFINDEX)) { -+ BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4); -+ off = offsetof(struct net_device, ifindex); -+ emit_load(r_A, r_s0, off, ctx); -+ } else { /* (code == (BPF_ANC | SKF_AD_HATYPE) */ -+ BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2); -+ off = offsetof(struct net_device, type); -+ emit_half_load_unsigned(r_A, r_s0, off, ctx); -+ } -+ break; -+ case BPF_ANC | SKF_AD_MARK: -+ ctx->flags |= SEEN_SKB | SEEN_A; -+ BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4); -+ off = offsetof(struct sk_buff, mark); -+ emit_load(r_A, r_skb, off, ctx); -+ break; -+ case BPF_ANC | SKF_AD_RXHASH: -+ ctx->flags |= SEEN_SKB | SEEN_A; -+ BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4); -+ off = offsetof(struct sk_buff, hash); -+ emit_load(r_A, r_skb, off, ctx); -+ break; -+ case BPF_ANC | SKF_AD_VLAN_TAG: -+ ctx->flags |= SEEN_SKB | SEEN_A; -+ BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, -+ vlan_tci) != 2); -+ off = offsetof(struct sk_buff, vlan_tci); -+ emit_half_load_unsigned(r_A, r_skb, off, ctx); -+ break; -+ case BPF_ANC | SKF_AD_VLAN_TAG_PRESENT: -+ ctx->flags |= SEEN_SKB | SEEN_A; -+ emit_load_byte(r_A, r_skb, PKT_VLAN_PRESENT_OFFSET(), ctx); -+ if (PKT_VLAN_PRESENT_BIT) -+ emit_srl(r_A, r_A, PKT_VLAN_PRESENT_BIT, ctx); -+ if (PKT_VLAN_PRESENT_BIT < 7) -+ emit_andi(r_A, r_A, 1, ctx); -+ break; -+ case BPF_ANC | SKF_AD_PKTTYPE: -+ ctx->flags |= SEEN_SKB; -+ -+ emit_load_byte(r_tmp, r_skb, PKT_TYPE_OFFSET(), ctx); -+ /* Keep only the last 3 bits */ -+ emit_andi(r_A, r_tmp, PKT_TYPE_MAX, ctx); -+#ifdef __BIG_ENDIAN_BITFIELD -+ /* Get the actual packet type to the lower 3 bits */ -+ emit_srl(r_A, r_A, 5, ctx); -+#endif -+ break; -+ case BPF_ANC | SKF_AD_QUEUE: -+ ctx->flags |= SEEN_SKB | SEEN_A; -+ BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, -+ queue_mapping) != 2); -+ BUILD_BUG_ON(offsetof(struct sk_buff, -+ queue_mapping) > 0xff); -+ off = offsetof(struct sk_buff, queue_mapping); -+ emit_half_load_unsigned(r_A, r_skb, off, ctx); -+ break; -+ default: -+ pr_debug("%s: Unhandled opcode: 0x%02x\n", __FILE__, -+ inst->code); -+ return -1; -+ } -+ } -+ -+ /* compute offsets only during the first pass */ -+ if (ctx->target == NULL) -+ ctx->offsets[i] = ctx->idx * 4; -+ -+ return 0; -+} -+ -+void bpf_jit_compile(struct bpf_prog *fp) -+{ -+ struct jit_ctx ctx; -+ unsigned int alloc_size, tmp_idx; -+ -+ if (!bpf_jit_enable) -+ return; -+ -+ memset(&ctx, 0, sizeof(ctx)); -+ -+ ctx.offsets = kcalloc(fp->len + 1, sizeof(*ctx.offsets), GFP_KERNEL); -+ if (ctx.offsets == NULL) -+ return; -+ -+ ctx.skf = fp; -+ -+ if (build_body(&ctx)) -+ goto out; -+ -+ tmp_idx = ctx.idx; -+ build_prologue(&ctx); -+ ctx.prologue_bytes = (ctx.idx - tmp_idx) * 4; -+ /* just to complete the ctx.idx count */ -+ build_epilogue(&ctx); -+ -+ alloc_size = 4 * ctx.idx; -+ ctx.target = module_alloc(alloc_size); -+ if (ctx.target == NULL) -+ goto out; -+ -+ /* Clean it */ -+ memset(ctx.target, 0, alloc_size); -+ -+ ctx.idx = 0; -+ -+ /* Generate the actual JIT code */ -+ build_prologue(&ctx); -+ build_body(&ctx); -+ build_epilogue(&ctx); -+ -+ /* Update the icache */ -+ flush_icache_range((ptr)ctx.target, (ptr)(ctx.target + ctx.idx)); -+ -+ if (bpf_jit_enable > 1) -+ /* Dump JIT code */ -+ bpf_jit_dump(fp->len, alloc_size, 2, ctx.target); -+ -+ fp->bpf_func = (void *)ctx.target; -+ fp->jited = 1; -+ -+out: -+ kfree(ctx.offsets); -+} -+ -+void bpf_jit_free(struct bpf_prog *fp) -+{ -+ if (fp->jited) -+ module_memfree(fp->bpf_func); -+ -+ bpf_prog_unlock_free(fp); -+} ---- /dev/null -+++ b/arch/mips/net/bpf_jit_asm.S -@@ -0,0 +1,285 @@ -+/* -+ * bpf_jib_asm.S: Packet/header access helper functions for MIPS/MIPS64 BPF -+ * compiler. -+ * -+ * Copyright (C) 2015 Imagination Technologies Ltd. -+ * Author: Markos Chandras <markos.chandras@imgtec.com> -+ * -+ * 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. -+ */ -+ -+#include <asm/asm.h> -+#include <asm/isa-rev.h> -+#include <asm/regdef.h> -+#include "bpf_jit.h" -+ -+/* ABI -+ * -+ * r_skb_hl skb header length -+ * r_skb_data skb data -+ * r_off(a1) offset register -+ * r_A BPF register A -+ * r_X PF register X -+ * r_skb(a0) *skb -+ * r_M *scratch memory -+ * r_skb_le skb length -+ * r_s0 Scratch register 0 -+ * r_s1 Scratch register 1 -+ * -+ * On entry: -+ * a0: *skb -+ * a1: offset (imm or imm + X) -+ * -+ * All non-BPF-ABI registers are free for use. On return, we only -+ * care about r_ret. The BPF-ABI registers are assumed to remain -+ * unmodified during the entire filter operation. -+ */ -+ -+#define skb a0 -+#define offset a1 -+#define SKF_LL_OFF (-0x200000) /* Can't include linux/filter.h in assembly */ -+ -+ /* We know better :) so prevent assembler reordering etc */ -+ .set noreorder -+ -+#define is_offset_negative(TYPE) \ -+ /* If offset is negative we have more work to do */ \ -+ slti t0, offset, 0; \ -+ bgtz t0, bpf_slow_path_##TYPE##_neg; \ -+ /* Be careful what follows in DS. */ -+ -+#define is_offset_in_header(SIZE, TYPE) \ -+ /* Reading from header? */ \ -+ addiu $r_s0, $r_skb_hl, -SIZE; \ -+ slt t0, $r_s0, offset; \ -+ bgtz t0, bpf_slow_path_##TYPE; \ -+ -+LEAF(sk_load_word) -+ is_offset_negative(word) -+FEXPORT(sk_load_word_positive) -+ is_offset_in_header(4, word) -+ /* Offset within header boundaries */ -+ PTR_ADDU t1, $r_skb_data, offset -+ .set reorder -+ lw $r_A, 0(t1) -+ .set noreorder -+#ifdef CONFIG_CPU_LITTLE_ENDIAN -+# if MIPS_ISA_REV >= 2 -+ wsbh t0, $r_A -+ rotr $r_A, t0, 16 -+# else -+ sll t0, $r_A, 24 -+ srl t1, $r_A, 24 -+ srl t2, $r_A, 8 -+ or t0, t0, t1 -+ andi t2, t2, 0xff00 -+ andi t1, $r_A, 0xff00 -+ or t0, t0, t2 -+ sll t1, t1, 8 -+ or $r_A, t0, t1 -+# endif -+#endif -+ jr $r_ra -+ move $r_ret, zero -+ END(sk_load_word) -+ -+LEAF(sk_load_half) -+ is_offset_negative(half) -+FEXPORT(sk_load_half_positive) -+ is_offset_in_header(2, half) -+ /* Offset within header boundaries */ -+ PTR_ADDU t1, $r_skb_data, offset -+ lhu $r_A, 0(t1) -+#ifdef CONFIG_CPU_LITTLE_ENDIAN -+# if MIPS_ISA_REV >= 2 -+ wsbh $r_A, $r_A -+# else -+ sll t0, $r_A, 8 -+ srl t1, $r_A, 8 -+ andi t0, t0, 0xff00 -+ or $r_A, t0, t1 -+# endif -+#endif -+ jr $r_ra -+ move $r_ret, zero -+ END(sk_load_half) -+ -+LEAF(sk_load_byte) -+ is_offset_negative(byte) -+FEXPORT(sk_load_byte_positive) -+ is_offset_in_header(1, byte) -+ /* Offset within header boundaries */ -+ PTR_ADDU t1, $r_skb_data, offset -+ lbu $r_A, 0(t1) -+ jr $r_ra -+ move $r_ret, zero -+ END(sk_load_byte) -+ -+/* -+ * call skb_copy_bits: -+ * (prototype in linux/skbuff.h) -+ * -+ * int skb_copy_bits(sk_buff *skb, int offset, void *to, int len) -+ * -+ * o32 mandates we leave 4 spaces for argument registers in case -+ * the callee needs to use them. Even though we don't care about -+ * the argument registers ourselves, we need to allocate that space -+ * to remain ABI compliant since the callee may want to use that space. -+ * We also allocate 2 more spaces for $r_ra and our return register (*to). -+ * -+ * n64 is a bit different. The *caller* will allocate the space to preserve -+ * the arguments. So in 64-bit kernels, we allocate the 4-arg space for no -+ * good reason but it does not matter that much really. -+ * -+ * (void *to) is returned in r_s0 -+ * -+ */ -+#ifdef CONFIG_CPU_LITTLE_ENDIAN -+#define DS_OFFSET(SIZE) (4 * SZREG) -+#else -+#define DS_OFFSET(SIZE) ((4 * SZREG) + (4 - SIZE)) -+#endif -+#define bpf_slow_path_common(SIZE) \ -+ /* Quick check. Are we within reasonable boundaries? */ \ -+ LONG_ADDIU $r_s1, $r_skb_len, -SIZE; \ -+ sltu $r_s0, offset, $r_s1; \ -+ beqz $r_s0, fault; \ -+ /* Load 4th argument in DS */ \ -+ LONG_ADDIU a3, zero, SIZE; \ -+ PTR_ADDIU $r_sp, $r_sp, -(6 * SZREG); \ -+ PTR_LA t0, skb_copy_bits; \ -+ PTR_S $r_ra, (5 * SZREG)($r_sp); \ -+ /* Assign low slot to a2 */ \ -+ PTR_ADDIU a2, $r_sp, DS_OFFSET(SIZE); \ -+ jalr t0; \ -+ /* Reset our destination slot (DS but it's ok) */ \ -+ INT_S zero, (4 * SZREG)($r_sp); \ -+ /* \ -+ * skb_copy_bits returns 0 on success and -EFAULT \ -+ * on error. Our data live in a2. Do not bother with \ -+ * our data if an error has been returned. \ -+ */ \ -+ /* Restore our frame */ \ -+ PTR_L $r_ra, (5 * SZREG)($r_sp); \ -+ INT_L $r_s0, (4 * SZREG)($r_sp); \ -+ bltz v0, fault; \ -+ PTR_ADDIU $r_sp, $r_sp, 6 * SZREG; \ -+ move $r_ret, zero; \ -+ -+NESTED(bpf_slow_path_word, (6 * SZREG), $r_sp) -+ bpf_slow_path_common(4) -+#ifdef CONFIG_CPU_LITTLE_ENDIAN -+# if MIPS_ISA_REV >= 2 -+ wsbh t0, $r_s0 -+ jr $r_ra -+ rotr $r_A, t0, 16 -+# else -+ sll t0, $r_s0, 24 -+ srl t1, $r_s0, 24 -+ srl t2, $r_s0, 8 -+ or t0, t0, t1 -+ andi t2, t2, 0xff00 -+ andi t1, $r_s0, 0xff00 -+ or t0, t0, t2 -+ sll t1, t1, 8 -+ jr $r_ra -+ or $r_A, t0, t1 -+# endif -+#else -+ jr $r_ra -+ move $r_A, $r_s0 -+#endif -+ -+ END(bpf_slow_path_word) -+ -+NESTED(bpf_slow_path_half, (6 * SZREG), $r_sp) -+ bpf_slow_path_common(2) -+#ifdef CONFIG_CPU_LITTLE_ENDIAN -+# if MIPS_ISA_REV >= 2 -+ jr $r_ra -+ wsbh $r_A, $r_s0 -+# else -+ sll t0, $r_s0, 8 -+ andi t1, $r_s0, 0xff00 -+ andi t0, t0, 0xff00 -+ srl t1, t1, 8 -+ jr $r_ra -+ or $r_A, t0, t1 -+# endif -+#else -+ jr $r_ra -+ move $r_A, $r_s0 -+#endif -+ -+ END(bpf_slow_path_half) -+ -+NESTED(bpf_slow_path_byte, (6 * SZREG), $r_sp) -+ bpf_slow_path_common(1) -+ jr $r_ra -+ move $r_A, $r_s0 -+ -+ END(bpf_slow_path_byte) -+ -+/* -+ * Negative entry points -+ */ -+ .macro bpf_is_end_of_data -+ li t0, SKF_LL_OFF -+ /* Reading link layer data? */ -+ slt t1, offset, t0 -+ bgtz t1, fault -+ /* Be careful what follows in DS. */ -+ .endm -+/* -+ * call skb_copy_bits: -+ * (prototype in linux/filter.h) -+ * -+ * void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, -+ * int k, unsigned int size) -+ * -+ * see above (bpf_slow_path_common) for ABI restrictions -+ */ -+#define bpf_negative_common(SIZE) \ -+ PTR_ADDIU $r_sp, $r_sp, -(6 * SZREG); \ -+ PTR_LA t0, bpf_internal_load_pointer_neg_helper; \ -+ PTR_S $r_ra, (5 * SZREG)($r_sp); \ -+ jalr t0; \ -+ li a2, SIZE; \ -+ PTR_L $r_ra, (5 * SZREG)($r_sp); \ -+ /* Check return pointer */ \ -+ beqz v0, fault; \ -+ PTR_ADDIU $r_sp, $r_sp, 6 * SZREG; \ -+ /* Preserve our pointer */ \ -+ move $r_s0, v0; \ -+ /* Set return value */ \ -+ move $r_ret, zero; \ -+ -+bpf_slow_path_word_neg: -+ bpf_is_end_of_data -+NESTED(sk_load_word_negative, (6 * SZREG), $r_sp) -+ bpf_negative_common(4) -+ jr $r_ra -+ lw $r_A, 0($r_s0) -+ END(sk_load_word_negative) -+ -+bpf_slow_path_half_neg: -+ bpf_is_end_of_data -+NESTED(sk_load_half_negative, (6 * SZREG), $r_sp) -+ bpf_negative_common(2) -+ jr $r_ra -+ lhu $r_A, 0($r_s0) -+ END(sk_load_half_negative) -+ -+bpf_slow_path_byte_neg: -+ bpf_is_end_of_data -+NESTED(sk_load_byte_negative, (6 * SZREG), $r_sp) -+ bpf_negative_common(1) -+ jr $r_ra -+ lbu $r_A, 0($r_s0) -+ END(sk_load_byte_negative) -+ -+fault: -+ jr $r_ra -+ addiu $r_ret, zero, 1 |