/*
- * Just-In-Time compiler for BPF filters on 32bit ARM
+ * Just-In-Time compiler for eBPF filters on 32bit ARM
*
+ * Copyright (c) 2017 Shubham Bansal <illusionist.neo@gmail.com>
* Copyright (c) 2011 Mircea Gherzan <mgherzan@gmail.com>
*
* This program is free software; you can redistribute it and/or modify it
* Free Software Foundation; version 2 of the License.
*/
+#include <linux/bpf.h>
#include <linux/bitops.h>
#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/if_vlan.h>
#include <asm/cacheflush.h>
-#include <asm/set_memory.h>
#include <asm/hwcap.h>
#include <asm/opcodes.h>
#include "bpf_jit_32.h"
+int bpf_jit_enable __read_mostly;
+
+#define STACK_OFFSET(k) (k)
+#define TMP_REG_1 (MAX_BPF_JIT_REG + 0) /* TEMP Register 1 */
+#define TMP_REG_2 (MAX_BPF_JIT_REG + 1) /* TEMP Register 2 */
+#define TCALL_CNT (MAX_BPF_JIT_REG + 2) /* Tail Call Count */
+
+/* Flags used for JIT optimization */
+#define SEEN_CALL (1 << 0)
+
+#define FLAG_IMM_OVERFLOW (1 << 0)
+
/*
- * ABI:
+ * Map eBPF registers to ARM 32bit registers or stack scratch space.
+ *
+ * 1. First argument is passed using the arm 32bit registers and rest of the
+ * arguments are passed on stack scratch space.
+ * 2. First callee-saved arugument is mapped to arm 32 bit registers and rest
+ * arguments are mapped to scratch space on stack.
+ * 3. We need two 64 bit temp registers to do complex operations on eBPF
+ * registers.
+ *
+ * As the eBPF registers are all 64 bit registers and arm has only 32 bit
+ * registers, we have to map each eBPF registers with two arm 32 bit regs or
+ * scratch memory space and we have to build eBPF 64 bit register from those.
*
- * r0 scratch register
- * r4 BPF register A
- * r5 BPF register X
- * r6 pointer to the skb
- * r7 skb->data
- * r8 skb_headlen(skb)
*/
+static const u8 bpf2a32[][2] = {
+ /* return value from in-kernel function, and exit value from eBPF */
+ [BPF_REG_0] = {ARM_R1, ARM_R0},
+ /* arguments from eBPF program to in-kernel function */
+ [BPF_REG_1] = {ARM_R3, ARM_R2},
+ /* Stored on stack scratch space */
+ [BPF_REG_2] = {STACK_OFFSET(0), STACK_OFFSET(4)},
+ [BPF_REG_3] = {STACK_OFFSET(8), STACK_OFFSET(12)},
+ [BPF_REG_4] = {STACK_OFFSET(16), STACK_OFFSET(20)},
+ [BPF_REG_5] = {STACK_OFFSET(24), STACK_OFFSET(28)},
+ /* callee saved registers that in-kernel function will preserve */
+ [BPF_REG_6] = {ARM_R5, ARM_R4},
+ /* Stored on stack scratch space */
+ [BPF_REG_7] = {STACK_OFFSET(32), STACK_OFFSET(36)},
+ [BPF_REG_8] = {STACK_OFFSET(40), STACK_OFFSET(44)},
+ [BPF_REG_9] = {STACK_OFFSET(48), STACK_OFFSET(52)},
+ /* Read only Frame Pointer to access Stack */
+ [BPF_REG_FP] = {STACK_OFFSET(56), STACK_OFFSET(60)},
+ /* Temporary Register for internal BPF JIT, can be used
+ * for constant blindings and others.
+ */
+ [TMP_REG_1] = {ARM_R7, ARM_R6},
+ [TMP_REG_2] = {ARM_R10, ARM_R8},
+ /* Tail call count. Stored on stack scratch space. */
+ [TCALL_CNT] = {STACK_OFFSET(64), STACK_OFFSET(68)},
+ /* temporary register for blinding constants.
+ * Stored on stack scratch space.
+ */
+ [BPF_REG_AX] = {STACK_OFFSET(72), STACK_OFFSET(76)},
+};
-#define r_scratch ARM_R0
-/* r1-r3 are (also) used for the unaligned loads on the non-ARMv7 slowpath */
-#define r_off ARM_R1
-#define r_A ARM_R4
-#define r_X ARM_R5
-#define r_skb ARM_R6
-#define r_skb_data ARM_R7
-#define r_skb_hl ARM_R8
-
-#define SCRATCH_SP_OFFSET 0
-#define SCRATCH_OFF(k) (SCRATCH_SP_OFFSET + 4 * (k))
-
-#define SEEN_MEM ((1 << BPF_MEMWORDS) - 1)
-#define SEEN_MEM_WORD(k) (1 << (k))
-#define SEEN_X (1 << BPF_MEMWORDS)
-#define SEEN_CALL (1 << (BPF_MEMWORDS + 1))
-#define SEEN_SKB (1 << (BPF_MEMWORDS + 2))
-#define SEEN_DATA (1 << (BPF_MEMWORDS + 3))
+#define dst_lo dst[1]
+#define dst_hi dst[0]
+#define src_lo src[1]
+#define src_hi src[0]
-#define FLAG_NEED_X_RESET (1 << 0)
-#define FLAG_IMM_OVERFLOW (1 << 1)
+/*
+ * JIT Context:
+ *
+ * prog : bpf_prog
+ * idx : index of current last JITed instruction.
+ * prologue_bytes : bytes used in prologue.
+ * epilogue_offset : offset of epilogue starting.
+ * seen : bit mask used for JIT optimization.
+ * offsets : array of eBPF instruction offsets in
+ * JITed code.
+ * target : final JITed code.
+ * epilogue_bytes : no of bytes used in epilogue.
+ * imm_count : no of immediate counts used for global
+ * variables.
+ * imms : array of global variable addresses.
+ */
struct jit_ctx {
- const struct bpf_prog *skf;
- unsigned idx;
- unsigned prologue_bytes;
- int ret0_fp_idx;
+ const struct bpf_prog *prog;
+ unsigned int idx;
+ unsigned int prologue_bytes;
+ unsigned int epilogue_offset;
u32 seen;
u32 flags;
u32 *offsets;
u32 *target;
+ u32 stack_size;
#if __LINUX_ARM_ARCH__ < 7
u16 epilogue_bytes;
u16 imm_count;
#endif
};
-int bpf_jit_enable __read_mostly;
-
-static inline int call_neg_helper(struct sk_buff *skb, int offset, void *ret,
- unsigned int size)
-{
- void *ptr = bpf_internal_load_pointer_neg_helper(skb, offset, size);
-
- if (!ptr)
- return -EFAULT;
- memcpy(ret, ptr, size);
- return 0;
-}
-
-static u64 jit_get_skb_b(struct sk_buff *skb, int offset)
-{
- u8 ret;
- int err;
-
- if (offset < 0)
- err = call_neg_helper(skb, offset, &ret, 1);
- else
- err = skb_copy_bits(skb, offset, &ret, 1);
-
- return (u64)err << 32 | ret;
-}
-
-static u64 jit_get_skb_h(struct sk_buff *skb, int offset)
-{
- u16 ret;
- int err;
-
- if (offset < 0)
- err = call_neg_helper(skb, offset, &ret, 2);
- else
- err = skb_copy_bits(skb, offset, &ret, 2);
-
- return (u64)err << 32 | ntohs(ret);
-}
-
-static u64 jit_get_skb_w(struct sk_buff *skb, int offset)
-{
- u32 ret;
- int err;
-
- if (offset < 0)
- err = call_neg_helper(skb, offset, &ret, 4);
- else
- err = skb_copy_bits(skb, offset, &ret, 4);
-
- return (u64)err << 32 | ntohl(ret);
-}
-
/*
* Wrappers which handle both OABI and EABI and assures Thumb2 interworking
* (where the assembly routines like __aeabi_uidiv could cause problems).
*/
-static u32 jit_udiv(u32 dividend, u32 divisor)
+static u32 jit_udiv32(u32 dividend, u32 divisor)
{
return dividend / divisor;
}
-static u32 jit_mod(u32 dividend, u32 divisor)
+static u32 jit_mod32(u32 dividend, u32 divisor)
{
return dividend % divisor;
}
_emit(ARM_COND_AL, inst, ctx);
}
-static u16 saved_regs(struct jit_ctx *ctx)
+/*
+ * Checks if immediate value can be converted to imm12(12 bits) value.
+ */
+static int16_t imm8m(u32 x)
{
- u16 ret = 0;
-
- if ((ctx->skf->len > 1) ||
- (ctx->skf->insns[0].code == (BPF_RET | BPF_A)))
- ret |= 1 << r_A;
-
-#ifdef CONFIG_FRAME_POINTER
- ret |= (1 << ARM_FP) | (1 << ARM_IP) | (1 << ARM_LR) | (1 << ARM_PC);
-#else
- if (ctx->seen & SEEN_CALL)
- ret |= 1 << ARM_LR;
-#endif
- if (ctx->seen & (SEEN_DATA | SEEN_SKB))
- ret |= 1 << r_skb;
- if (ctx->seen & SEEN_DATA)
- ret |= (1 << r_skb_data) | (1 << r_skb_hl);
- if (ctx->seen & SEEN_X)
- ret |= 1 << r_X;
-
- return ret;
-}
+ u32 rot;
-static inline int mem_words_used(struct jit_ctx *ctx)
-{
- /* yes, we do waste some stack space IF there are "holes" in the set" */
- return fls(ctx->seen & SEEN_MEM);
+ for (rot = 0; rot < 16; rot++)
+ if ((x & ~ror32(0xff, 2 * rot)) == 0)
+ return rol32(x, 2 * rot) | (rot << 8);
+ return -1;
}
+/*
+ * Initializes the JIT space with undefined instructions.
+ */
static void jit_fill_hole(void *area, unsigned int size)
{
u32 *ptr;
*ptr++ = __opcode_to_mem_arm(ARM_INST_UDF);
}
-static void build_prologue(struct jit_ctx *ctx)
-{
- u16 reg_set = saved_regs(ctx);
- u16 off;
-
-#ifdef CONFIG_FRAME_POINTER
- emit(ARM_MOV_R(ARM_IP, ARM_SP), ctx);
- emit(ARM_PUSH(reg_set), ctx);
- emit(ARM_SUB_I(ARM_FP, ARM_IP, 4), ctx);
-#else
- if (reg_set)
- emit(ARM_PUSH(reg_set), ctx);
-#endif
-
- if (ctx->seen & (SEEN_DATA | SEEN_SKB))
- emit(ARM_MOV_R(r_skb, ARM_R0), ctx);
-
- if (ctx->seen & SEEN_DATA) {
- off = offsetof(struct sk_buff, data);
- emit(ARM_LDR_I(r_skb_data, r_skb, off), ctx);
- /* headlen = len - data_len */
- off = offsetof(struct sk_buff, len);
- emit(ARM_LDR_I(r_skb_hl, r_skb, off), ctx);
- off = offsetof(struct sk_buff, data_len);
- emit(ARM_LDR_I(r_scratch, r_skb, off), ctx);
- emit(ARM_SUB_R(r_skb_hl, r_skb_hl, r_scratch), ctx);
- }
-
- if (ctx->flags & FLAG_NEED_X_RESET)
- emit(ARM_MOV_I(r_X, 0), ctx);
-
- /* do not leak kernel data to userspace */
- if (bpf_needs_clear_a(&ctx->skf->insns[0]))
- emit(ARM_MOV_I(r_A, 0), ctx);
-
- /* stack space for the BPF_MEM words */
- if (ctx->seen & SEEN_MEM)
- emit(ARM_SUB_I(ARM_SP, ARM_SP, mem_words_used(ctx) * 4), ctx);
-}
-
-static void build_epilogue(struct jit_ctx *ctx)
-{
- u16 reg_set = saved_regs(ctx);
-
- if (ctx->seen & SEEN_MEM)
- emit(ARM_ADD_I(ARM_SP, ARM_SP, mem_words_used(ctx) * 4), ctx);
-
- reg_set &= ~(1 << ARM_LR);
+/* Stack must be multiples of 16 Bytes */
+#define STACK_ALIGN(sz) (((sz) + 3) & ~3)
-#ifdef CONFIG_FRAME_POINTER
- /* the first instruction of the prologue was: mov ip, sp */
- reg_set &= ~(1 << ARM_IP);
- reg_set |= (1 << ARM_SP);
- emit(ARM_LDM(ARM_SP, reg_set), ctx);
-#else
- if (reg_set) {
- if (ctx->seen & SEEN_CALL)
- reg_set |= 1 << ARM_PC;
- emit(ARM_POP(reg_set), ctx);
- }
+/* Stack space for BPF_REG_2, BPF_REG_3, BPF_REG_4,
+ * BPF_REG_5, BPF_REG_7, BPF_REG_8, BPF_REG_9,
+ * BPF_REG_FP and Tail call counts.
+ */
+#define SCRATCH_SIZE 80
- if (!(ctx->seen & SEEN_CALL))
- emit(ARM_BX(ARM_LR), ctx);
-#endif
-}
+/* total stack size used in JITed code */
+#define _STACK_SIZE \
+ (ctx->prog->aux->stack_depth + \
+ + SCRATCH_SIZE + \
+ + 4 /* extra for skb_copy_bits buffer */)
-static int16_t imm8m(u32 x)
-{
- u32 rot;
+#define STACK_SIZE STACK_ALIGN(_STACK_SIZE)
- for (rot = 0; rot < 16; rot++)
- if ((x & ~ror32(0xff, 2 * rot)) == 0)
- return rol32(x, 2 * rot) | (rot << 8);
+/* Get the offset of eBPF REGISTERs stored on scratch space. */
+#define STACK_VAR(off) (STACK_SIZE-off-4)
- return -1;
-}
+/* Offset of skb_copy_bits buffer */
+#define SKB_BUFFER STACK_VAR(SCRATCH_SIZE)
#if __LINUX_ARM_ARCH__ < 7
static u16 imm_offset(u32 k, struct jit_ctx *ctx)
{
- unsigned i = 0, offset;
+ unsigned int i = 0, offset;
u16 imm;
/* on the "fake" run we just count them (duplicates included) */
ctx->imms[i] = k;
/* constants go just after the epilogue */
- offset = ctx->offsets[ctx->skf->len];
+ offset = ctx->offsets[ctx->prog->len - 1] * 4;
offset += ctx->prologue_bytes;
offset += ctx->epilogue_bytes;
offset += i * 4;
#endif /* __LINUX_ARM_ARCH__ */
+static inline int bpf2a32_offset(int bpf_to, int bpf_from,
+ const struct jit_ctx *ctx) {
+ int to, from;
+
+ if (ctx->target == NULL)
+ return 0;
+ to = ctx->offsets[bpf_to];
+ from = ctx->offsets[bpf_from];
+
+ return to - from - 1;
+}
+
/*
* Move an immediate that's not an imm8m to a core register.
*/
-static inline void emit_mov_i_no8m(int rd, u32 val, struct jit_ctx *ctx)
+static inline void emit_mov_i_no8m(const u8 rd, u32 val, struct jit_ctx *ctx)
{
#if __LINUX_ARM_ARCH__ < 7
emit(ARM_LDR_I(rd, ARM_PC, imm_offset(val, ctx)), ctx);
#endif
}
-static inline void emit_mov_i(int rd, u32 val, struct jit_ctx *ctx)
+static inline void emit_mov_i(const u8 rd, u32 val, struct jit_ctx *ctx)
{
int imm12 = imm8m(val);
emit_mov_i_no8m(rd, val, ctx);
}
-#if __LINUX_ARM_ARCH__ < 6
-
-static void emit_load_be32(u8 cond, u8 r_res, u8 r_addr, struct jit_ctx *ctx)
+static inline void emit_blx_r(u8 tgt_reg, struct jit_ctx *ctx)
{
- _emit(cond, ARM_LDRB_I(ARM_R3, r_addr, 1), ctx);
- _emit(cond, ARM_LDRB_I(ARM_R1, r_addr, 0), ctx);
- _emit(cond, ARM_LDRB_I(ARM_R2, r_addr, 3), ctx);
- _emit(cond, ARM_LSL_I(ARM_R3, ARM_R3, 16), ctx);
- _emit(cond, ARM_LDRB_I(ARM_R0, r_addr, 2), ctx);
- _emit(cond, ARM_ORR_S(ARM_R3, ARM_R3, ARM_R1, SRTYPE_LSL, 24), ctx);
- _emit(cond, ARM_ORR_R(ARM_R3, ARM_R3, ARM_R2), ctx);
- _emit(cond, ARM_ORR_S(r_res, ARM_R3, ARM_R0, SRTYPE_LSL, 8), ctx);
+ ctx->seen |= SEEN_CALL;
+#if __LINUX_ARM_ARCH__ < 5
+ emit(ARM_MOV_R(ARM_LR, ARM_PC), ctx);
+
+ if (elf_hwcap & HWCAP_THUMB)
+ emit(ARM_BX(tgt_reg), ctx);
+ else
+ emit(ARM_MOV_R(ARM_PC, tgt_reg), ctx);
+#else
+ emit(ARM_BLX_R(tgt_reg), ctx);
+#endif
}
-static void emit_load_be16(u8 cond, u8 r_res, u8 r_addr, struct jit_ctx *ctx)
+static inline int epilogue_offset(const struct jit_ctx *ctx)
{
- _emit(cond, ARM_LDRB_I(ARM_R1, r_addr, 0), ctx);
- _emit(cond, ARM_LDRB_I(ARM_R2, r_addr, 1), ctx);
- _emit(cond, ARM_ORR_S(r_res, ARM_R2, ARM_R1, SRTYPE_LSL, 8), ctx);
+ int to, from;
+ /* No need for 1st dummy run */
+ if (ctx->target == NULL)
+ return 0;
+ to = ctx->epilogue_offset;
+ from = ctx->idx;
+
+ return to - from - 2;
}
-static inline void emit_swap16(u8 r_dst, u8 r_src, struct jit_ctx *ctx)
+static inline void emit_udivmod(u8 rd, u8 rm, u8 rn, struct jit_ctx *ctx, u8 op)
{
- /* r_dst = (r_src << 8) | (r_src >> 8) */
- emit(ARM_LSL_I(ARM_R1, r_src, 8), ctx);
- emit(ARM_ORR_S(r_dst, ARM_R1, r_src, SRTYPE_LSR, 8), ctx);
+ const u8 *tmp = bpf2a32[TMP_REG_1];
+ s32 jmp_offset;
+
+ /* checks if divisor is zero or not. If it is, then
+ * exit directly.
+ */
+ emit(ARM_CMP_I(rn, 0), ctx);
+ _emit(ARM_COND_EQ, ARM_MOV_I(ARM_R0, 0), ctx);
+ jmp_offset = epilogue_offset(ctx);
+ _emit(ARM_COND_EQ, ARM_B(jmp_offset), ctx);
+#if __LINUX_ARM_ARCH__ == 7
+ if (elf_hwcap & HWCAP_IDIVA) {
+ if (op == BPF_DIV)
+ emit(ARM_UDIV(rd, rm, rn), ctx);
+ else {
+ emit(ARM_UDIV(ARM_IP, rm, rn), ctx);
+ emit(ARM_MLS(rd, rn, ARM_IP, rm), ctx);
+ }
+ return;
+ }
+#endif
/*
- * we need to mask out the bits set in r_dst[23:16] due to
- * the first shift instruction.
- *
- * note that 0x8ff is the encoded immediate 0x00ff0000.
+ * For BPF_ALU | BPF_DIV | BPF_K instructions
+ * As ARM_R1 and ARM_R0 contains 1st argument of bpf
+ * function, we need to save it on caller side to save
+ * it from getting destroyed within callee.
+ * After the return from the callee, we restore ARM_R0
+ * ARM_R1.
*/
- emit(ARM_BIC_I(r_dst, r_dst, 0x8ff), ctx);
-}
+ if (rn != ARM_R1) {
+ emit(ARM_MOV_R(tmp[0], ARM_R1), ctx);
+ emit(ARM_MOV_R(ARM_R1, rn), ctx);
+ }
+ if (rm != ARM_R0) {
+ emit(ARM_MOV_R(tmp[1], ARM_R0), ctx);
+ emit(ARM_MOV_R(ARM_R0, rm), ctx);
+ }
-#else /* ARMv6+ */
+ /* Call appropriate function */
+ ctx->seen |= SEEN_CALL;
+ emit_mov_i(ARM_IP, op == BPF_DIV ?
+ (u32)jit_udiv32 : (u32)jit_mod32, ctx);
+ emit_blx_r(ARM_IP, ctx);
-static void emit_load_be32(u8 cond, u8 r_res, u8 r_addr, struct jit_ctx *ctx)
-{
- _emit(cond, ARM_LDR_I(r_res, r_addr, 0), ctx);
-#ifdef __LITTLE_ENDIAN
- _emit(cond, ARM_REV(r_res, r_res), ctx);
-#endif
+ /* Save return value */
+ if (rd != ARM_R0)
+ emit(ARM_MOV_R(rd, ARM_R0), ctx);
+
+ /* Restore ARM_R0 and ARM_R1 */
+ if (rn != ARM_R1)
+ emit(ARM_MOV_R(ARM_R1, tmp[0]), ctx);
+ if (rm != ARM_R0)
+ emit(ARM_MOV_R(ARM_R0, tmp[1]), ctx);
}
-static void emit_load_be16(u8 cond, u8 r_res, u8 r_addr, struct jit_ctx *ctx)
+/* Checks whether BPF register is on scratch stack space or not. */
+static inline bool is_on_stack(u8 bpf_reg)
{
- _emit(cond, ARM_LDRH_I(r_res, r_addr, 0), ctx);
-#ifdef __LITTLE_ENDIAN
- _emit(cond, ARM_REV16(r_res, r_res), ctx);
-#endif
+ static u8 stack_regs[] = {BPF_REG_AX, BPF_REG_3, BPF_REG_4, BPF_REG_5,
+ BPF_REG_7, BPF_REG_8, BPF_REG_9, TCALL_CNT,
+ BPF_REG_2, BPF_REG_FP};
+ int i, reg_len = sizeof(stack_regs);
+
+ for (i = 0 ; i < reg_len ; i++) {
+ if (bpf_reg == stack_regs[i])
+ return true;
+ }
+ return false;
}
-static inline void emit_swap16(u8 r_dst __maybe_unused,
- u8 r_src __maybe_unused,
- struct jit_ctx *ctx __maybe_unused)
+static inline void emit_a32_mov_i(const u8 dst, const u32 val,
+ bool dstk, struct jit_ctx *ctx)
{
-#ifdef __LITTLE_ENDIAN
- emit(ARM_REV16(r_dst, r_src), ctx);
-#endif
+ const u8 *tmp = bpf2a32[TMP_REG_1];
+
+ if (dstk) {
+ emit_mov_i(tmp[1], val, ctx);
+ emit(ARM_STR_I(tmp[1], ARM_SP, STACK_VAR(dst)), ctx);
+ } else {
+ emit_mov_i(dst, val, ctx);
+ }
}
-#endif /* __LINUX_ARM_ARCH__ < 6 */
+/* Sign extended move */
+static inline void emit_a32_mov_i64(const bool is64, const u8 dst[],
+ const u32 val, bool dstk,
+ struct jit_ctx *ctx) {
+ u32 hi = 0;
+ if (is64 && (val & (1<<31)))
+ hi = (u32)~0;
+ emit_a32_mov_i(dst_lo, val, dstk, ctx);
+ emit_a32_mov_i(dst_hi, hi, dstk, ctx);
+}
-/* Compute the immediate value for a PC-relative branch. */
-static inline u32 b_imm(unsigned tgt, struct jit_ctx *ctx)
-{
- u32 imm;
+static inline void emit_a32_add_r(const u8 dst, const u8 src,
+ const bool is64, const bool hi,
+ struct jit_ctx *ctx) {
+ /* 64 bit :
+ * adds dst_lo, dst_lo, src_lo
+ * adc dst_hi, dst_hi, src_hi
+ * 32 bit :
+ * add dst_lo, dst_lo, src_lo
+ */
+ if (!hi && is64)
+ emit(ARM_ADDS_R(dst, dst, src), ctx);
+ else if (hi && is64)
+ emit(ARM_ADC_R(dst, dst, src), ctx);
+ else
+ emit(ARM_ADD_R(dst, dst, src), ctx);
+}
- if (ctx->target == NULL)
- return 0;
- /*
- * BPF allows only forward jumps and the offset of the target is
- * still the one computed during the first pass.
+static inline void emit_a32_sub_r(const u8 dst, const u8 src,
+ const bool is64, const bool hi,
+ struct jit_ctx *ctx) {
+ /* 64 bit :
+ * subs dst_lo, dst_lo, src_lo
+ * sbc dst_hi, dst_hi, src_hi
+ * 32 bit :
+ * sub dst_lo, dst_lo, src_lo
*/
- imm = ctx->offsets[tgt] + ctx->prologue_bytes - (ctx->idx * 4 + 8);
+ if (!hi && is64)
+ emit(ARM_SUBS_R(dst, dst, src), ctx);
+ else if (hi && is64)
+ emit(ARM_SBC_R(dst, dst, src), ctx);
+ else
+ emit(ARM_SUB_R(dst, dst, src), ctx);
+}
- return imm >> 2;
+static inline void emit_alu_r(const u8 dst, const u8 src, const bool is64,
+ const bool hi, const u8 op, struct jit_ctx *ctx){
+ switch (BPF_OP(op)) {
+ /* dst = dst + src */
+ case BPF_ADD:
+ emit_a32_add_r(dst, src, is64, hi, ctx);
+ break;
+ /* dst = dst - src */
+ case BPF_SUB:
+ emit_a32_sub_r(dst, src, is64, hi, ctx);
+ break;
+ /* dst = dst | src */
+ case BPF_OR:
+ emit(ARM_ORR_R(dst, dst, src), ctx);
+ break;
+ /* dst = dst & src */
+ case BPF_AND:
+ emit(ARM_AND_R(dst, dst, src), ctx);
+ break;
+ /* dst = dst ^ src */
+ case BPF_XOR:
+ emit(ARM_EOR_R(dst, dst, src), ctx);
+ break;
+ /* dst = dst * src */
+ case BPF_MUL:
+ emit(ARM_MUL(dst, dst, src), ctx);
+ break;
+ /* dst = dst << src */
+ case BPF_LSH:
+ emit(ARM_LSL_R(dst, dst, src), ctx);
+ break;
+ /* dst = dst >> src */
+ case BPF_RSH:
+ emit(ARM_LSR_R(dst, dst, src), ctx);
+ break;
+ /* dst = dst >> src (signed)*/
+ case BPF_ARSH:
+ emit(ARM_MOV_SR(dst, dst, SRTYPE_ASR, src), ctx);
+ break;
+ }
}
-#define OP_IMM3(op, r1, r2, imm_val, ctx) \
- do { \
- imm12 = imm8m(imm_val); \
- if (imm12 < 0) { \
- emit_mov_i_no8m(r_scratch, imm_val, ctx); \
- emit(op ## _R((r1), (r2), r_scratch), ctx); \
- } else { \
- emit(op ## _I((r1), (r2), imm12), ctx); \
- } \
- } while (0)
-
-static inline void emit_err_ret(u8 cond, struct jit_ctx *ctx)
-{
- if (ctx->ret0_fp_idx >= 0) {
- _emit(cond, ARM_B(b_imm(ctx->ret0_fp_idx, ctx)), ctx);
- /* NOP to keep the size constant between passes */
- emit(ARM_MOV_R(ARM_R0, ARM_R0), ctx);
+/* ALU operation (32 bit)
+ * dst = dst (op) src
+ */
+static inline void emit_a32_alu_r(const u8 dst, const u8 src,
+ bool dstk, bool sstk,
+ struct jit_ctx *ctx, const bool is64,
+ const bool hi, const u8 op) {
+ const u8 *tmp = bpf2a32[TMP_REG_1];
+ u8 rn = sstk ? tmp[1] : src;
+
+ if (sstk)
+ emit(ARM_LDR_I(rn, ARM_SP, STACK_VAR(src)), ctx);
+
+ /* ALU operation */
+ if (dstk) {
+ emit(ARM_LDR_I(tmp[0], ARM_SP, STACK_VAR(dst)), ctx);
+ emit_alu_r(tmp[0], rn, is64, hi, op, ctx);
+ emit(ARM_STR_I(tmp[0], ARM_SP, STACK_VAR(dst)), ctx);
} else {
- _emit(cond, ARM_MOV_I(ARM_R0, 0), ctx);
- _emit(cond, ARM_B(b_imm(ctx->skf->len, ctx)), ctx);
+ emit_alu_r(dst, rn, is64, hi, op, ctx);
}
}
-static inline void emit_blx_r(u8 tgt_reg, struct jit_ctx *ctx)
-{
-#if __LINUX_ARM_ARCH__ < 5
- emit(ARM_MOV_R(ARM_LR, ARM_PC), ctx);
+/* ALU operation (64 bit) */
+static inline void emit_a32_alu_r64(const bool is64, const u8 dst[],
+ const u8 src[], bool dstk,
+ bool sstk, struct jit_ctx *ctx,
+ const u8 op) {
+ emit_a32_alu_r(dst_lo, src_lo, dstk, sstk, ctx, is64, false, op);
+ if (is64)
+ emit_a32_alu_r(dst_hi, src_hi, dstk, sstk, ctx, is64, true, op);
+ else
+ emit_a32_mov_i(dst_hi, 0, dstk, ctx);
+}
- if (elf_hwcap & HWCAP_THUMB)
- emit(ARM_BX(tgt_reg), ctx);
+/* dst = imm (4 bytes)*/
+static inline void emit_a32_mov_r(const u8 dst, const u8 src,
+ bool dstk, bool sstk,
+ struct jit_ctx *ctx) {
+ const u8 *tmp = bpf2a32[TMP_REG_1];
+ u8 rt = sstk ? tmp[0] : src;
+
+ if (sstk)
+ emit(ARM_LDR_I(tmp[0], ARM_SP, STACK_VAR(src)), ctx);
+ if (dstk)
+ emit(ARM_STR_I(rt, ARM_SP, STACK_VAR(dst)), ctx);
else
- emit(ARM_MOV_R(ARM_PC, tgt_reg), ctx);
-#else
- emit(ARM_BLX_R(tgt_reg), ctx);
-#endif
+ emit(ARM_MOV_R(dst, rt), ctx);
}
-static inline void emit_udivmod(u8 rd, u8 rm, u8 rn, struct jit_ctx *ctx,
- int bpf_op)
-{
-#if __LINUX_ARM_ARCH__ == 7
- if (elf_hwcap & HWCAP_IDIVA) {
- if (bpf_op == BPF_DIV)
- emit(ARM_UDIV(rd, rm, rn), ctx);
- else {
- emit(ARM_UDIV(ARM_R3, rm, rn), ctx);
- emit(ARM_MLS(rd, rn, ARM_R3, rm), ctx);
- }
- return;
+/* dst = src */
+static inline void emit_a32_mov_r64(const bool is64, const u8 dst[],
+ const u8 src[], bool dstk,
+ bool sstk, struct jit_ctx *ctx) {
+ emit_a32_mov_r(dst_lo, src_lo, dstk, sstk, ctx);
+ if (is64) {
+ /* complete 8 byte move */
+ emit_a32_mov_r(dst_hi, src_hi, dstk, sstk, ctx);
+ } else {
+ /* Zero out high 4 bytes */
+ emit_a32_mov_i(dst_hi, 0, dstk, ctx);
}
-#endif
+}
- /*
- * For BPF_ALU | BPF_DIV | BPF_K instructions, rm is ARM_R4
- * (r_A) and rn is ARM_R0 (r_scratch) so load rn first into
- * ARM_R1 to avoid accidentally overwriting ARM_R0 with rm
- * before using it as a source for ARM_R1.
- *
- * For BPF_ALU | BPF_DIV | BPF_X rm is ARM_R4 (r_A) and rn is
- * ARM_R5 (r_X) so there is no particular register overlap
- * issues.
- */
- if (rn != ARM_R1)
- emit(ARM_MOV_R(ARM_R1, rn), ctx);
- if (rm != ARM_R0)
- emit(ARM_MOV_R(ARM_R0, rm), ctx);
+/* Shift operations */
+static inline void emit_a32_alu_i(const u8 dst, const u32 val, bool dstk,
+ struct jit_ctx *ctx, const u8 op) {
+ const u8 *tmp = bpf2a32[TMP_REG_1];
+ u8 rd = dstk ? tmp[0] : dst;
+
+ if (dstk)
+ emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst)), ctx);
+
+ /* Do shift operation */
+ switch (op) {
+ case BPF_LSH:
+ emit(ARM_LSL_I(rd, rd, val), ctx);
+ break;
+ case BPF_RSH:
+ emit(ARM_LSR_I(rd, rd, val), ctx);
+ break;
+ case BPF_NEG:
+ emit(ARM_RSB_I(rd, rd, val), ctx);
+ break;
+ }
+ if (dstk)
+ emit(ARM_STR_I(rd, ARM_SP, STACK_VAR(dst)), ctx);
+}
+
+/* dst = ~dst (64 bit) */
+static inline void emit_a32_neg64(const u8 dst[], bool dstk,
+ struct jit_ctx *ctx){
+ const u8 *tmp = bpf2a32[TMP_REG_1];
+ u8 rd = dstk ? tmp[1] : dst[1];
+ u8 rm = dstk ? tmp[0] : dst[0];
+
+ /* Setup Operand */
+ if (dstk) {
+ emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ }
+
+ /* Do Negate Operation */
+ emit(ARM_RSBS_I(rd, rd, 0), ctx);
+ emit(ARM_RSC_I(rm, rm, 0), ctx);
+
+ if (dstk) {
+ emit(ARM_STR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_STR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ }
+}
+
+/* dst = dst << src */
+static inline void emit_a32_lsh_r64(const u8 dst[], const u8 src[], bool dstk,
+ bool sstk, struct jit_ctx *ctx) {
+ const u8 *tmp = bpf2a32[TMP_REG_1];
+ const u8 *tmp2 = bpf2a32[TMP_REG_2];
+
+ /* Setup Operands */
+ u8 rt = sstk ? tmp2[1] : src_lo;
+ u8 rd = dstk ? tmp[1] : dst_lo;
+ u8 rm = dstk ? tmp[0] : dst_hi;
+
+ if (sstk)
+ emit(ARM_LDR_I(rt, ARM_SP, STACK_VAR(src_lo)), ctx);
+ if (dstk) {
+ emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ }
+
+ /* Do LSH operation */
+ emit(ARM_SUB_I(ARM_IP, rt, 32), ctx);
+ emit(ARM_RSB_I(tmp2[0], rt, 32), ctx);
+ /* As we are using ARM_LR */
ctx->seen |= SEEN_CALL;
- emit_mov_i(ARM_R3, bpf_op == BPF_DIV ? (u32)jit_udiv : (u32)jit_mod,
- ctx);
- emit_blx_r(ARM_R3, ctx);
+ emit(ARM_MOV_SR(ARM_LR, rm, SRTYPE_ASL, rt), ctx);
+ emit(ARM_ORR_SR(ARM_LR, ARM_LR, rd, SRTYPE_ASL, ARM_IP), ctx);
+ emit(ARM_ORR_SR(ARM_IP, ARM_LR, rd, SRTYPE_LSR, tmp2[0]), ctx);
+ emit(ARM_MOV_SR(ARM_LR, rd, SRTYPE_ASL, rt), ctx);
+
+ if (dstk) {
+ emit(ARM_STR_I(ARM_LR, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_STR_I(ARM_IP, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ } else {
+ emit(ARM_MOV_R(rd, ARM_LR), ctx);
+ emit(ARM_MOV_R(rm, ARM_IP), ctx);
+ }
+}
- if (rd != ARM_R0)
- emit(ARM_MOV_R(rd, ARM_R0), ctx);
+/* dst = dst >> src (signed)*/
+static inline void emit_a32_arsh_r64(const u8 dst[], const u8 src[], bool dstk,
+ bool sstk, struct jit_ctx *ctx) {
+ const u8 *tmp = bpf2a32[TMP_REG_1];
+ const u8 *tmp2 = bpf2a32[TMP_REG_2];
+ /* Setup Operands */
+ u8 rt = sstk ? tmp2[1] : src_lo;
+ u8 rd = dstk ? tmp[1] : dst_lo;
+ u8 rm = dstk ? tmp[0] : dst_hi;
+
+ if (sstk)
+ emit(ARM_LDR_I(rt, ARM_SP, STACK_VAR(src_lo)), ctx);
+ if (dstk) {
+ emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ }
+
+ /* Do the ARSH operation */
+ emit(ARM_RSB_I(ARM_IP, rt, 32), ctx);
+ emit(ARM_SUBS_I(tmp2[0], rt, 32), ctx);
+ /* As we are using ARM_LR */
+ ctx->seen |= SEEN_CALL;
+ emit(ARM_MOV_SR(ARM_LR, rd, SRTYPE_LSR, rt), ctx);
+ emit(ARM_ORR_SR(ARM_LR, ARM_LR, rm, SRTYPE_ASL, ARM_IP), ctx);
+ _emit(ARM_COND_MI, ARM_B(0), ctx);
+ emit(ARM_ORR_SR(ARM_LR, ARM_LR, rm, SRTYPE_ASR, tmp2[0]), ctx);
+ emit(ARM_MOV_SR(ARM_IP, rm, SRTYPE_ASR, rt), ctx);
+ if (dstk) {
+ emit(ARM_STR_I(ARM_LR, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_STR_I(ARM_IP, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ } else {
+ emit(ARM_MOV_R(rd, ARM_LR), ctx);
+ emit(ARM_MOV_R(rm, ARM_IP), ctx);
+ }
+}
+
+/* dst = dst >> src */
+static inline void emit_a32_lsr_r64(const u8 dst[], const u8 src[], bool dstk,
+ bool sstk, struct jit_ctx *ctx) {
+ const u8 *tmp = bpf2a32[TMP_REG_1];
+ const u8 *tmp2 = bpf2a32[TMP_REG_2];
+ /* Setup Operands */
+ u8 rt = sstk ? tmp2[1] : src_lo;
+ u8 rd = dstk ? tmp[1] : dst_lo;
+ u8 rm = dstk ? tmp[0] : dst_hi;
+
+ if (sstk)
+ emit(ARM_LDR_I(rt, ARM_SP, STACK_VAR(src_lo)), ctx);
+ if (dstk) {
+ emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ }
+
+ /* Do LSH operation */
+ emit(ARM_RSB_I(ARM_IP, rt, 32), ctx);
+ emit(ARM_SUBS_I(tmp2[0], rt, 32), ctx);
+ /* As we are using ARM_LR */
+ ctx->seen |= SEEN_CALL;
+ emit(ARM_MOV_SR(ARM_LR, rd, SRTYPE_LSR, rt), ctx);
+ emit(ARM_ORR_SR(ARM_LR, ARM_LR, rm, SRTYPE_ASL, ARM_IP), ctx);
+ emit(ARM_ORR_SR(ARM_LR, ARM_LR, rm, SRTYPE_LSR, tmp2[0]), ctx);
+ emit(ARM_MOV_SR(ARM_IP, rm, SRTYPE_LSR, rt), ctx);
+ if (dstk) {
+ emit(ARM_STR_I(ARM_LR, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_STR_I(ARM_IP, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ } else {
+ emit(ARM_MOV_R(rd, ARM_LR), ctx);
+ emit(ARM_MOV_R(rm, ARM_IP), ctx);
+ }
}
-static inline void update_on_xread(struct jit_ctx *ctx)
+/* dst = dst << val */
+static inline void emit_a32_lsh_i64(const u8 dst[], bool dstk,
+ const u32 val, struct jit_ctx *ctx){
+ const u8 *tmp = bpf2a32[TMP_REG_1];
+ const u8 *tmp2 = bpf2a32[TMP_REG_2];
+ /* Setup operands */
+ u8 rd = dstk ? tmp[1] : dst_lo;
+ u8 rm = dstk ? tmp[0] : dst_hi;
+
+ if (dstk) {
+ emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ }
+
+ /* Do LSH operation */
+ if (val < 32) {
+ emit(ARM_MOV_SI(tmp2[0], rm, SRTYPE_ASL, val), ctx);
+ emit(ARM_ORR_SI(rm, tmp2[0], rd, SRTYPE_LSR, 32 - val), ctx);
+ emit(ARM_MOV_SI(rd, rd, SRTYPE_ASL, val), ctx);
+ } else {
+ if (val == 32)
+ emit(ARM_MOV_R(rm, rd), ctx);
+ else
+ emit(ARM_MOV_SI(rm, rd, SRTYPE_ASL, val - 32), ctx);
+ emit(ARM_EOR_R(rd, rd, rd), ctx);
+ }
+
+ if (dstk) {
+ emit(ARM_STR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_STR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ }
+}
+
+/* dst = dst >> val */
+static inline void emit_a32_lsr_i64(const u8 dst[], bool dstk,
+ const u32 val, struct jit_ctx *ctx) {
+ const u8 *tmp = bpf2a32[TMP_REG_1];
+ const u8 *tmp2 = bpf2a32[TMP_REG_2];
+ /* Setup operands */
+ u8 rd = dstk ? tmp[1] : dst_lo;
+ u8 rm = dstk ? tmp[0] : dst_hi;
+
+ if (dstk) {
+ emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ }
+
+ /* Do LSR operation */
+ if (val < 32) {
+ emit(ARM_MOV_SI(tmp2[1], rd, SRTYPE_LSR, val), ctx);
+ emit(ARM_ORR_SI(rd, tmp2[1], rm, SRTYPE_ASL, 32 - val), ctx);
+ emit(ARM_MOV_SI(rm, rm, SRTYPE_LSR, val), ctx);
+ } else if (val == 32) {
+ emit(ARM_MOV_R(rd, rm), ctx);
+ emit(ARM_MOV_I(rm, 0), ctx);
+ } else {
+ emit(ARM_MOV_SI(rd, rm, SRTYPE_LSR, val - 32), ctx);
+ emit(ARM_MOV_I(rm, 0), ctx);
+ }
+
+ if (dstk) {
+ emit(ARM_STR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_STR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ }
+}
+
+/* dst = dst >> val (signed) */
+static inline void emit_a32_arsh_i64(const u8 dst[], bool dstk,
+ const u32 val, struct jit_ctx *ctx){
+ const u8 *tmp = bpf2a32[TMP_REG_1];
+ const u8 *tmp2 = bpf2a32[TMP_REG_2];
+ /* Setup operands */
+ u8 rd = dstk ? tmp[1] : dst_lo;
+ u8 rm = dstk ? tmp[0] : dst_hi;
+
+ if (dstk) {
+ emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ }
+
+ /* Do ARSH operation */
+ if (val < 32) {
+ emit(ARM_MOV_SI(tmp2[1], rd, SRTYPE_LSR, val), ctx);
+ emit(ARM_ORR_SI(rd, tmp2[1], rm, SRTYPE_ASL, 32 - val), ctx);
+ emit(ARM_MOV_SI(rm, rm, SRTYPE_ASR, val), ctx);
+ } else if (val == 32) {
+ emit(ARM_MOV_R(rd, rm), ctx);
+ emit(ARM_MOV_SI(rm, rm, SRTYPE_ASR, 31), ctx);
+ } else {
+ emit(ARM_MOV_SI(rd, rm, SRTYPE_ASR, val - 32), ctx);
+ emit(ARM_MOV_SI(rm, rm, SRTYPE_ASR, 31), ctx);
+ }
+
+ if (dstk) {
+ emit(ARM_STR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_STR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ }
+}
+
+static inline void emit_a32_mul_r64(const u8 dst[], const u8 src[], bool dstk,
+ bool sstk, struct jit_ctx *ctx) {
+ const u8 *tmp = bpf2a32[TMP_REG_1];
+ const u8 *tmp2 = bpf2a32[TMP_REG_2];
+ /* Setup operands for multiplication */
+ u8 rd = dstk ? tmp[1] : dst_lo;
+ u8 rm = dstk ? tmp[0] : dst_hi;
+ u8 rt = sstk ? tmp2[1] : src_lo;
+ u8 rn = sstk ? tmp2[0] : src_hi;
+
+ if (dstk) {
+ emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ }
+ if (sstk) {
+ emit(ARM_LDR_I(rt, ARM_SP, STACK_VAR(src_lo)), ctx);
+ emit(ARM_LDR_I(rn, ARM_SP, STACK_VAR(src_hi)), ctx);
+ }
+
+ /* Do Multiplication */
+ emit(ARM_MUL(ARM_IP, rd, rn), ctx);
+ emit(ARM_MUL(ARM_LR, rm, rt), ctx);
+ /* As we are using ARM_LR */
+ ctx->seen |= SEEN_CALL;
+ emit(ARM_ADD_R(ARM_LR, ARM_IP, ARM_LR), ctx);
+
+ emit(ARM_UMULL(ARM_IP, rm, rd, rt), ctx);
+ emit(ARM_ADD_R(rm, ARM_LR, rm), ctx);
+ if (dstk) {
+ emit(ARM_STR_I(ARM_IP, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_STR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ } else {
+ emit(ARM_MOV_R(rd, ARM_IP), ctx);
+ }
+}
+
+/* *(size *)(dst + off) = src */
+static inline void emit_str_r(const u8 dst, const u8 src, bool dstk,
+ const s32 off, struct jit_ctx *ctx, const u8 sz){
+ const u8 *tmp = bpf2a32[TMP_REG_1];
+ u8 rd = dstk ? tmp[1] : dst;
+
+ if (dstk)
+ emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst)), ctx);
+ if (off) {
+ emit_a32_mov_i(tmp[0], off, false, ctx);
+ emit(ARM_ADD_R(tmp[0], rd, tmp[0]), ctx);
+ rd = tmp[0];
+ }
+ switch (sz) {
+ case BPF_W:
+ /* Store a Word */
+ emit(ARM_STR_I(src, rd, 0), ctx);
+ break;
+ case BPF_H:
+ /* Store a HalfWord */
+ emit(ARM_STRH_I(src, rd, 0), ctx);
+ break;
+ case BPF_B:
+ /* Store a Byte */
+ emit(ARM_STRB_I(src, rd, 0), ctx);
+ break;
+ }
+}
+
+/* dst = *(size*)(src + off) */
+static inline void emit_ldx_r(const u8 dst, const u8 src, bool dstk,
+ const s32 off, struct jit_ctx *ctx, const u8 sz){
+ const u8 *tmp = bpf2a32[TMP_REG_1];
+ u8 rd = dstk ? tmp[1] : dst;
+ u8 rm = src;
+
+ if (off) {
+ emit_a32_mov_i(tmp[0], off, false, ctx);
+ emit(ARM_ADD_R(tmp[0], tmp[0], src), ctx);
+ rm = tmp[0];
+ }
+ switch (sz) {
+ case BPF_W:
+ /* Load a Word */
+ emit(ARM_LDR_I(rd, rm, 0), ctx);
+ break;
+ case BPF_H:
+ /* Load a HalfWord */
+ emit(ARM_LDRH_I(rd, rm, 0), ctx);
+ break;
+ case BPF_B:
+ /* Load a Byte */
+ emit(ARM_LDRB_I(rd, rm, 0), ctx);
+ break;
+ }
+ if (dstk)
+ emit(ARM_STR_I(rd, ARM_SP, STACK_VAR(dst)), ctx);
+}
+
+/* Arithmatic Operation */
+static inline void emit_ar_r(const u8 rd, const u8 rt, const u8 rm,
+ const u8 rn, struct jit_ctx *ctx, u8 op) {
+ switch (op) {
+ case BPF_JSET:
+ ctx->seen |= SEEN_CALL;
+ emit(ARM_AND_R(ARM_IP, rt, rn), ctx);
+ emit(ARM_AND_R(ARM_LR, rd, rm), ctx);
+ emit(ARM_ORRS_R(ARM_IP, ARM_LR, ARM_IP), ctx);
+ break;
+ case BPF_JEQ:
+ case BPF_JNE:
+ case BPF_JGT:
+ case BPF_JGE:
+ case BPF_JLE:
+ case BPF_JLT:
+ emit(ARM_CMP_R(rd, rm), ctx);
+ _emit(ARM_COND_EQ, ARM_CMP_R(rt, rn), ctx);
+ break;
+ case BPF_JSLE:
+ case BPF_JSGT:
+ emit(ARM_CMP_R(rn, rt), ctx);
+ emit(ARM_SBCS_R(ARM_IP, rm, rd), ctx);
+ break;
+ case BPF_JSLT:
+ case BPF_JSGE:
+ emit(ARM_CMP_R(rt, rn), ctx);
+ emit(ARM_SBCS_R(ARM_IP, rd, rm), ctx);
+ break;
+ }
+}
+
+static int out_offset = -1; /* initialized on the first pass of build_body() */
+static int emit_bpf_tail_call(struct jit_ctx *ctx)
{
- if (!(ctx->seen & SEEN_X))
- ctx->flags |= FLAG_NEED_X_RESET;
- ctx->seen |= SEEN_X;
+ /* bpf_tail_call(void *prog_ctx, struct bpf_array *array, u64 index) */
+ const u8 *r2 = bpf2a32[BPF_REG_2];
+ const u8 *r3 = bpf2a32[BPF_REG_3];
+ const u8 *tmp = bpf2a32[TMP_REG_1];
+ const u8 *tmp2 = bpf2a32[TMP_REG_2];
+ const u8 *tcc = bpf2a32[TCALL_CNT];
+ const int idx0 = ctx->idx;
+#define cur_offset (ctx->idx - idx0)
+#define jmp_offset (out_offset - (cur_offset))
+ u32 off, lo, hi;
+
+ /* if (index >= array->map.max_entries)
+ * goto out;
+ */
+ off = offsetof(struct bpf_array, map.max_entries);
+ /* array->map.max_entries */
+ emit_a32_mov_i(tmp[1], off, false, ctx);
+ emit(ARM_LDR_I(tmp2[1], ARM_SP, STACK_VAR(r2[1])), ctx);
+ emit(ARM_LDR_R(tmp[1], tmp2[1], tmp[1]), ctx);
+ /* index (64 bit) */
+ emit(ARM_LDR_I(tmp2[1], ARM_SP, STACK_VAR(r3[1])), ctx);
+ /* index >= array->map.max_entries */
+ emit(ARM_CMP_R(tmp2[1], tmp[1]), ctx);
+ _emit(ARM_COND_CS, ARM_B(jmp_offset), ctx);
+
+ /* if (tail_call_cnt > MAX_TAIL_CALL_CNT)
+ * goto out;
+ * tail_call_cnt++;
+ */
+ lo = (u32)MAX_TAIL_CALL_CNT;
+ hi = (u32)((u64)MAX_TAIL_CALL_CNT >> 32);
+ emit(ARM_LDR_I(tmp[1], ARM_SP, STACK_VAR(tcc[1])), ctx);
+ emit(ARM_LDR_I(tmp[0], ARM_SP, STACK_VAR(tcc[0])), ctx);
+ emit(ARM_CMP_I(tmp[0], hi), ctx);
+ _emit(ARM_COND_EQ, ARM_CMP_I(tmp[1], lo), ctx);
+ _emit(ARM_COND_HI, ARM_B(jmp_offset), ctx);
+ emit(ARM_ADDS_I(tmp[1], tmp[1], 1), ctx);
+ emit(ARM_ADC_I(tmp[0], tmp[0], 0), ctx);
+ emit(ARM_STR_I(tmp[1], ARM_SP, STACK_VAR(tcc[1])), ctx);
+ emit(ARM_STR_I(tmp[0], ARM_SP, STACK_VAR(tcc[0])), ctx);
+
+ /* prog = array->ptrs[index]
+ * if (prog == NULL)
+ * goto out;
+ */
+ off = offsetof(struct bpf_array, ptrs);
+ emit_a32_mov_i(tmp[1], off, false, ctx);
+ emit(ARM_LDR_I(tmp2[1], ARM_SP, STACK_VAR(r2[1])), ctx);
+ emit(ARM_ADD_R(tmp[1], tmp2[1], tmp[1]), ctx);
+ emit(ARM_LDR_I(tmp2[1], ARM_SP, STACK_VAR(r3[1])), ctx);
+ emit(ARM_MOV_SI(tmp[0], tmp2[1], SRTYPE_ASL, 2), ctx);
+ emit(ARM_LDR_R(tmp[1], tmp[1], tmp[0]), ctx);
+ emit(ARM_CMP_I(tmp[1], 0), ctx);
+ _emit(ARM_COND_EQ, ARM_B(jmp_offset), ctx);
+
+ /* goto *(prog->bpf_func + prologue_size); */
+ off = offsetof(struct bpf_prog, bpf_func);
+ emit_a32_mov_i(tmp2[1], off, false, ctx);
+ emit(ARM_LDR_R(tmp[1], tmp[1], tmp2[1]), ctx);
+ emit(ARM_ADD_I(tmp[1], tmp[1], ctx->prologue_bytes), ctx);
+ emit(ARM_BX(tmp[1]), ctx);
+
+ /* out: */
+ if (out_offset == -1)
+ out_offset = cur_offset;
+ if (cur_offset != out_offset) {
+ pr_err_once("tail_call out_offset = %d, expected %d!\n",
+ cur_offset, out_offset);
+ return -1;
+ }
+ return 0;
+#undef cur_offset
+#undef jmp_offset
}
-static int build_body(struct jit_ctx *ctx)
+/* 0xabcd => 0xcdab */
+static inline void emit_rev16(const u8 rd, const u8 rn, struct jit_ctx *ctx)
{
- void *load_func[] = {jit_get_skb_b, jit_get_skb_h, jit_get_skb_w};
- const struct bpf_prog *prog = ctx->skf;
- const struct sock_filter *inst;
- unsigned i, load_order, off, condt;
- int imm12;
- u32 k;
+#if __LINUX_ARM_ARCH__ < 6
+ const u8 *tmp2 = bpf2a32[TMP_REG_2];
+
+ emit(ARM_AND_I(tmp2[1], rn, 0xff), ctx);
+ emit(ARM_MOV_SI(tmp2[0], rn, SRTYPE_LSR, 8), ctx);
+ emit(ARM_AND_I(tmp2[0], tmp2[0], 0xff), ctx);
+ emit(ARM_ORR_SI(rd, tmp2[0], tmp2[1], SRTYPE_LSL, 8), ctx);
+#else /* ARMv6+ */
+ emit(ARM_REV16(rd, rn), ctx);
+#endif
+}
- for (i = 0; i < prog->len; i++) {
- u16 code;
+/* 0xabcdefgh => 0xghefcdab */
+static inline void emit_rev32(const u8 rd, const u8 rn, struct jit_ctx *ctx)
+{
+#if __LINUX_ARM_ARCH__ < 6
+ const u8 *tmp2 = bpf2a32[TMP_REG_2];
+
+ emit(ARM_AND_I(tmp2[1], rn, 0xff), ctx);
+ emit(ARM_MOV_SI(tmp2[0], rn, SRTYPE_LSR, 24), ctx);
+ emit(ARM_ORR_SI(ARM_IP, tmp2[0], tmp2[1], SRTYPE_LSL, 24), ctx);
+
+ emit(ARM_MOV_SI(tmp2[1], rn, SRTYPE_LSR, 8), ctx);
+ emit(ARM_AND_I(tmp2[1], tmp2[1], 0xff), ctx);
+ emit(ARM_MOV_SI(tmp2[0], rn, SRTYPE_LSR, 16), ctx);
+ emit(ARM_AND_I(tmp2[0], tmp2[0], 0xff), ctx);
+ emit(ARM_MOV_SI(tmp2[0], tmp2[0], SRTYPE_LSL, 8), ctx);
+ emit(ARM_ORR_SI(tmp2[0], tmp2[0], tmp2[1], SRTYPE_LSL, 16), ctx);
+ emit(ARM_ORR_R(rd, ARM_IP, tmp2[0]), ctx);
+
+#else /* ARMv6+ */
+ emit(ARM_REV(rd, rn), ctx);
+#endif
+}
- inst = &(prog->insns[i]);
- /* K as an immediate value operand */
- k = inst->k;
- code = bpf_anc_helper(inst);
+// push the scratch stack register on top of the stack
+static inline void emit_push_r64(const u8 src[], const u8 shift,
+ struct jit_ctx *ctx)
+{
+ const u8 *tmp2 = bpf2a32[TMP_REG_2];
+ u16 reg_set = 0;
- /* compute offsets only in the fake pass */
- if (ctx->target == NULL)
- ctx->offsets[i] = ctx->idx * 4;
+ emit(ARM_LDR_I(tmp2[1], ARM_SP, STACK_VAR(src[1]+shift)), ctx);
+ emit(ARM_LDR_I(tmp2[0], ARM_SP, STACK_VAR(src[0]+shift)), ctx);
+
+ reg_set = (1 << tmp2[1]) | (1 << tmp2[0]);
+ emit(ARM_PUSH(reg_set), ctx);
+}
+
+static void build_prologue(struct jit_ctx *ctx)
+{
+ const u8 r0 = bpf2a32[BPF_REG_0][1];
+ const u8 r2 = bpf2a32[BPF_REG_1][1];
+ const u8 r3 = bpf2a32[BPF_REG_1][0];
+ const u8 r4 = bpf2a32[BPF_REG_6][1];
+ const u8 r5 = bpf2a32[BPF_REG_6][0];
+ const u8 r6 = bpf2a32[TMP_REG_1][1];
+ const u8 r7 = bpf2a32[TMP_REG_1][0];
+ const u8 r8 = bpf2a32[TMP_REG_2][1];
+ const u8 r10 = bpf2a32[TMP_REG_2][0];
+ const u8 fplo = bpf2a32[BPF_REG_FP][1];
+ const u8 fphi = bpf2a32[BPF_REG_FP][0];
+ const u8 sp = ARM_SP;
+ const u8 *tcc = bpf2a32[TCALL_CNT];
+
+ u16 reg_set = 0;
+
+ /*
+ * eBPF prog stack layout
+ *
+ * high
+ * original ARM_SP => +-----+ eBPF prologue
+ * |FP/LR|
+ * current ARM_FP => +-----+
+ * | ... | callee saved registers
+ * eBPF fp register => +-----+ <= (BPF_FP)
+ * | ... | eBPF JIT scratch space
+ * | | eBPF prog stack
+ * +-----+
+ * |RSVD | JIT scratchpad
+ * current A64_SP => +-----+ <= (BPF_FP - STACK_SIZE)
+ * | |
+ * | ... | Function call stack
+ * | |
+ * +-----+
+ * low
+ */
+
+ /* Save callee saved registers. */
+ reg_set |= (1<<r4) | (1<<r5) | (1<<r6) | (1<<r7) | (1<<r8) | (1<<r10);
+#ifdef CONFIG_FRAME_POINTER
+ reg_set |= (1<<ARM_FP) | (1<<ARM_IP) | (1<<ARM_LR) | (1<<ARM_PC);
+ emit(ARM_MOV_R(ARM_IP, sp), ctx);
+ emit(ARM_PUSH(reg_set), ctx);
+ emit(ARM_SUB_I(ARM_FP, ARM_IP, 4), ctx);
+#else
+ /* Check if call instruction exists in BPF body */
+ if (ctx->seen & SEEN_CALL)
+ reg_set |= (1<<ARM_LR);
+ emit(ARM_PUSH(reg_set), ctx);
+#endif
+ /* Save frame pointer for later */
+ emit(ARM_SUB_I(ARM_IP, sp, SCRATCH_SIZE), ctx);
+
+ ctx->stack_size = imm8m(STACK_SIZE);
+
+ /* Set up function call stack */
+ emit(ARM_SUB_I(ARM_SP, ARM_SP, ctx->stack_size), ctx);
- switch (code) {
- case BPF_LD | BPF_IMM:
- emit_mov_i(r_A, k, ctx);
+ /* Set up BPF prog stack base register */
+ emit_a32_mov_r(fplo, ARM_IP, true, false, ctx);
+ emit_a32_mov_i(fphi, 0, true, ctx);
+
+ /* mov r4, 0 */
+ emit(ARM_MOV_I(r4, 0), ctx);
+
+ /* Move BPF_CTX to BPF_R1 */
+ emit(ARM_MOV_R(r3, r4), ctx);
+ emit(ARM_MOV_R(r2, r0), ctx);
+ /* Initialize Tail Count */
+ emit(ARM_STR_I(r4, ARM_SP, STACK_VAR(tcc[0])), ctx);
+ emit(ARM_STR_I(r4, ARM_SP, STACK_VAR(tcc[1])), ctx);
+ /* end of prologue */
+}
+
+static void build_epilogue(struct jit_ctx *ctx)
+{
+ const u8 r4 = bpf2a32[BPF_REG_6][1];
+ const u8 r5 = bpf2a32[BPF_REG_6][0];
+ const u8 r6 = bpf2a32[TMP_REG_1][1];
+ const u8 r7 = bpf2a32[TMP_REG_1][0];
+ const u8 r8 = bpf2a32[TMP_REG_2][1];
+ const u8 r10 = bpf2a32[TMP_REG_2][0];
+ u16 reg_set = 0;
+
+ /* unwind function call stack */
+ emit(ARM_ADD_I(ARM_SP, ARM_SP, ctx->stack_size), ctx);
+
+ /* restore callee saved registers. */
+ reg_set |= (1<<r4) | (1<<r5) | (1<<r6) | (1<<r7) | (1<<r8) | (1<<r10);
+#ifdef CONFIG_FRAME_POINTER
+ /* the first instruction of the prologue was: mov ip, sp */
+ reg_set |= (1<<ARM_FP) | (1<<ARM_SP) | (1<<ARM_PC);
+ emit(ARM_LDM(ARM_SP, reg_set), ctx);
+#else
+ if (ctx->seen & SEEN_CALL)
+ reg_set |= (1<<ARM_PC);
+ /* Restore callee saved registers. */
+ emit(ARM_POP(reg_set), ctx);
+ /* Return back to the callee function */
+ if (!(ctx->seen & SEEN_CALL))
+ emit(ARM_BX(ARM_LR), ctx);
+#endif
+}
+
+/*
+ * Convert an eBPF instruction to native instruction, i.e
+ * JITs an eBPF instruction.
+ * Returns :
+ * 0 - Successfully JITed an 8-byte eBPF instruction
+ * >0 - Successfully JITed a 16-byte eBPF instruction
+ * <0 - Failed to JIT.
+ */
+static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
+{
+ const u8 code = insn->code;
+ const u8 *dst = bpf2a32[insn->dst_reg];
+ const u8 *src = bpf2a32[insn->src_reg];
+ const u8 *tmp = bpf2a32[TMP_REG_1];
+ const u8 *tmp2 = bpf2a32[TMP_REG_2];
+ const s16 off = insn->off;
+ const s32 imm = insn->imm;
+ const int i = insn - ctx->prog->insnsi;
+ const bool is64 = BPF_CLASS(code) == BPF_ALU64;
+ const bool dstk = is_on_stack(insn->dst_reg);
+ const bool sstk = is_on_stack(insn->src_reg);
+ u8 rd, rt, rm, rn;
+ s32 jmp_offset;
+
+#define check_imm(bits, imm) do { \
+ if ((((imm) > 0) && ((imm) >> (bits))) || \
+ (((imm) < 0) && (~(imm) >> (bits)))) { \
+ pr_info("[%2d] imm=%d(0x%x) out of range\n", \
+ i, imm, imm); \
+ return -EINVAL; \
+ } \
+} while (0)
+#define check_imm24(imm) check_imm(24, imm)
+
+ switch (code) {
+ /* ALU operations */
+
+ /* dst = src */
+ case BPF_ALU | BPF_MOV | BPF_K:
+ case BPF_ALU | BPF_MOV | BPF_X:
+ case BPF_ALU64 | BPF_MOV | BPF_K:
+ case BPF_ALU64 | BPF_MOV | BPF_X:
+ switch (BPF_SRC(code)) {
+ case BPF_X:
+ emit_a32_mov_r64(is64, dst, src, dstk, sstk, ctx);
break;
- case BPF_LD | BPF_W | BPF_LEN:
- ctx->seen |= SEEN_SKB;
- BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4);
- emit(ARM_LDR_I(r_A, r_skb,
- offsetof(struct sk_buff, len)), ctx);
+ case BPF_K:
+ /* Sign-extend immediate value to destination reg */
+ emit_a32_mov_i64(is64, dst, imm, dstk, ctx);
break;
- case BPF_LD | BPF_MEM:
- /* A = scratch[k] */
- ctx->seen |= SEEN_MEM_WORD(k);
- emit(ARM_LDR_I(r_A, ARM_SP, SCRATCH_OFF(k)), ctx);
+ }
+ break;
+ /* dst = dst + src/imm */
+ /* dst = dst - src/imm */
+ /* dst = dst | src/imm */
+ /* dst = dst & src/imm */
+ /* dst = dst ^ src/imm */
+ /* dst = dst * src/imm */
+ /* dst = dst << src */
+ /* dst = dst >> src */
+ case BPF_ALU | BPF_ADD | BPF_K:
+ case BPF_ALU | BPF_ADD | BPF_X:
+ case BPF_ALU | BPF_SUB | BPF_K:
+ case BPF_ALU | BPF_SUB | BPF_X:
+ case BPF_ALU | BPF_OR | BPF_K:
+ case BPF_ALU | BPF_OR | BPF_X:
+ case BPF_ALU | BPF_AND | BPF_K:
+ case BPF_ALU | BPF_AND | BPF_X:
+ case BPF_ALU | BPF_XOR | BPF_K:
+ case BPF_ALU | BPF_XOR | BPF_X:
+ case BPF_ALU | BPF_MUL | BPF_K:
+ case BPF_ALU | BPF_MUL | BPF_X:
+ case BPF_ALU | BPF_LSH | BPF_X:
+ case BPF_ALU | BPF_RSH | BPF_X:
+ case BPF_ALU | BPF_ARSH | BPF_K:
+ case BPF_ALU | BPF_ARSH | BPF_X:
+ case BPF_ALU64 | BPF_ADD | BPF_K:
+ case BPF_ALU64 | BPF_ADD | BPF_X:
+ case BPF_ALU64 | BPF_SUB | BPF_K:
+ case BPF_ALU64 | BPF_SUB | BPF_X:
+ case BPF_ALU64 | BPF_OR | BPF_K:
+ case BPF_ALU64 | BPF_OR | BPF_X:
+ case BPF_ALU64 | BPF_AND | BPF_K:
+ case BPF_ALU64 | BPF_AND | BPF_X:
+ case BPF_ALU64 | BPF_XOR | BPF_K:
+ case BPF_ALU64 | BPF_XOR | BPF_X:
+ switch (BPF_SRC(code)) {
+ case BPF_X:
+ emit_a32_alu_r64(is64, dst, src, dstk, sstk,
+ ctx, BPF_OP(code));
break;
- case BPF_LD | BPF_W | BPF_ABS:
- load_order = 2;
- goto load;
- case BPF_LD | BPF_H | BPF_ABS:
- load_order = 1;
- goto load;
- case BPF_LD | BPF_B | BPF_ABS:
- load_order = 0;
-load:
- emit_mov_i(r_off, k, ctx);
-load_common:
- ctx->seen |= SEEN_DATA | SEEN_CALL;
-
- if (load_order > 0) {
- emit(ARM_SUB_I(r_scratch, r_skb_hl,
- 1 << load_order), ctx);
- emit(ARM_CMP_R(r_scratch, r_off), ctx);
- condt = ARM_COND_GE;
- } else {
- emit(ARM_CMP_R(r_skb_hl, r_off), ctx);
- condt = ARM_COND_HI;
- }
-
- /*
- * test for negative offset, only if we are
- * currently scheduled to take the fast
- * path. this will update the flags so that
- * the slowpath instruction are ignored if the
- * offset is negative.
- *
- * for loard_order == 0 the HI condition will
- * make loads at offset 0 take the slow path too.
+ case BPF_K:
+ /* Move immediate value to the temporary register
+ * and then do the ALU operation on the temporary
+ * register as this will sign-extend the immediate
+ * value into temporary reg and then it would be
+ * safe to do the operation on it.
*/
- _emit(condt, ARM_CMP_I(r_off, 0), ctx);
-
- _emit(condt, ARM_ADD_R(r_scratch, r_off, r_skb_data),
- ctx);
-
- if (load_order == 0)
- _emit(condt, ARM_LDRB_I(r_A, r_scratch, 0),
- ctx);
- else if (load_order == 1)
- emit_load_be16(condt, r_A, r_scratch, ctx);
- else if (load_order == 2)
- emit_load_be32(condt, r_A, r_scratch, ctx);
-
- _emit(condt, ARM_B(b_imm(i + 1, ctx)), ctx);
-
- /* the slowpath */
- emit_mov_i(ARM_R3, (u32)load_func[load_order], ctx);
- emit(ARM_MOV_R(ARM_R0, r_skb), ctx);
- /* the offset is already in R1 */
- emit_blx_r(ARM_R3, ctx);
- /* check the result of skb_copy_bits */
- emit(ARM_CMP_I(ARM_R1, 0), ctx);
- emit_err_ret(ARM_COND_NE, ctx);
- emit(ARM_MOV_R(r_A, ARM_R0), ctx);
+ emit_a32_mov_i64(is64, tmp2, imm, false, ctx);
+ emit_a32_alu_r64(is64, dst, tmp2, dstk, false,
+ ctx, BPF_OP(code));
break;
- case BPF_LD | BPF_W | BPF_IND:
- load_order = 2;
- goto load_ind;
- case BPF_LD | BPF_H | BPF_IND:
- load_order = 1;
- goto load_ind;
- case BPF_LD | BPF_B | BPF_IND:
- load_order = 0;
-load_ind:
- update_on_xread(ctx);
- OP_IMM3(ARM_ADD, r_off, r_X, k, ctx);
- goto load_common;
- case BPF_LDX | BPF_IMM:
- ctx->seen |= SEEN_X;
- emit_mov_i(r_X, k, ctx);
+ }
+ break;
+ /* dst = dst / src(imm) */
+ /* dst = dst % src(imm) */
+ case BPF_ALU | BPF_DIV | BPF_K:
+ case BPF_ALU | BPF_DIV | BPF_X:
+ case BPF_ALU | BPF_MOD | BPF_K:
+ case BPF_ALU | BPF_MOD | BPF_X:
+ rt = src_lo;
+ rd = dstk ? tmp2[1] : dst_lo;
+ if (dstk)
+ emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ switch (BPF_SRC(code)) {
+ case BPF_X:
+ rt = sstk ? tmp2[0] : rt;
+ if (sstk)
+ emit(ARM_LDR_I(rt, ARM_SP, STACK_VAR(src_lo)),
+ ctx);
break;
- case BPF_LDX | BPF_W | BPF_LEN:
- ctx->seen |= SEEN_X | SEEN_SKB;
- emit(ARM_LDR_I(r_X, r_skb,
- offsetof(struct sk_buff, len)), ctx);
+ case BPF_K:
+ rt = tmp2[0];
+ emit_a32_mov_i(rt, imm, false, ctx);
break;
- case BPF_LDX | BPF_MEM:
- ctx->seen |= SEEN_X | SEEN_MEM_WORD(k);
- emit(ARM_LDR_I(r_X, ARM_SP, SCRATCH_OFF(k)), ctx);
+ }
+ emit_udivmod(rd, rd, rt, ctx, BPF_OP(code));
+ if (dstk)
+ emit(ARM_STR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit_a32_mov_i(dst_hi, 0, dstk, ctx);
+ break;
+ case BPF_ALU64 | BPF_DIV | BPF_K:
+ case BPF_ALU64 | BPF_DIV | BPF_X:
+ case BPF_ALU64 | BPF_MOD | BPF_K:
+ case BPF_ALU64 | BPF_MOD | BPF_X:
+ goto notyet;
+ /* dst = dst >> imm */
+ /* dst = dst << imm */
+ case BPF_ALU | BPF_RSH | BPF_K:
+ case BPF_ALU | BPF_LSH | BPF_K:
+ if (unlikely(imm > 31))
+ return -EINVAL;
+ if (imm)
+ emit_a32_alu_i(dst_lo, imm, dstk, ctx, BPF_OP(code));
+ emit_a32_mov_i(dst_hi, 0, dstk, ctx);
+ break;
+ /* dst = dst << imm */
+ case BPF_ALU64 | BPF_LSH | BPF_K:
+ if (unlikely(imm > 63))
+ return -EINVAL;
+ emit_a32_lsh_i64(dst, dstk, imm, ctx);
+ break;
+ /* dst = dst >> imm */
+ case BPF_ALU64 | BPF_RSH | BPF_K:
+ if (unlikely(imm > 63))
+ return -EINVAL;
+ emit_a32_lsr_i64(dst, dstk, imm, ctx);
+ break;
+ /* dst = dst << src */
+ case BPF_ALU64 | BPF_LSH | BPF_X:
+ emit_a32_lsh_r64(dst, src, dstk, sstk, ctx);
+ break;
+ /* dst = dst >> src */
+ case BPF_ALU64 | BPF_RSH | BPF_X:
+ emit_a32_lsr_r64(dst, src, dstk, sstk, ctx);
+ break;
+ /* dst = dst >> src (signed) */
+ case BPF_ALU64 | BPF_ARSH | BPF_X:
+ emit_a32_arsh_r64(dst, src, dstk, sstk, ctx);
+ break;
+ /* dst = dst >> imm (signed) */
+ case BPF_ALU64 | BPF_ARSH | BPF_K:
+ if (unlikely(imm > 63))
+ return -EINVAL;
+ emit_a32_arsh_i64(dst, dstk, imm, ctx);
+ break;
+ /* dst = ~dst */
+ case BPF_ALU | BPF_NEG:
+ emit_a32_alu_i(dst_lo, 0, dstk, ctx, BPF_OP(code));
+ emit_a32_mov_i(dst_hi, 0, dstk, ctx);
+ break;
+ /* dst = ~dst (64 bit) */
+ case BPF_ALU64 | BPF_NEG:
+ emit_a32_neg64(dst, dstk, ctx);
+ break;
+ /* dst = dst * src/imm */
+ case BPF_ALU64 | BPF_MUL | BPF_X:
+ case BPF_ALU64 | BPF_MUL | BPF_K:
+ switch (BPF_SRC(code)) {
+ case BPF_X:
+ emit_a32_mul_r64(dst, src, dstk, sstk, ctx);
break;
- case BPF_LDX | BPF_B | BPF_MSH:
- /* x = ((*(frame + k)) & 0xf) << 2; */
- ctx->seen |= SEEN_X | SEEN_DATA | SEEN_CALL;
- /* the interpreter should deal with the negative K */
- if ((int)k < 0)
- return -1;
- /* offset in r1: we might have to take the slow path */
- emit_mov_i(r_off, k, ctx);
- emit(ARM_CMP_R(r_skb_hl, r_off), ctx);
-
- /* load in r0: common with the slowpath */
- _emit(ARM_COND_HI, ARM_LDRB_R(ARM_R0, r_skb_data,
- ARM_R1), ctx);
- /*
- * emit_mov_i() might generate one or two instructions,
- * the same holds for emit_blx_r()
+ case BPF_K:
+ /* Move immediate value to the temporary register
+ * and then do the multiplication on it as this
+ * will sign-extend the immediate value into temp
+ * reg then it would be safe to do the operation
+ * on it.
*/
- _emit(ARM_COND_HI, ARM_B(b_imm(i + 1, ctx) - 2), ctx);
-
- emit(ARM_MOV_R(ARM_R0, r_skb), ctx);
- /* r_off is r1 */
- emit_mov_i(ARM_R3, (u32)jit_get_skb_b, ctx);
- emit_blx_r(ARM_R3, ctx);
- /* check the return value of skb_copy_bits */
- emit(ARM_CMP_I(ARM_R1, 0), ctx);
- emit_err_ret(ARM_COND_NE, ctx);
-
- emit(ARM_AND_I(r_X, ARM_R0, 0x00f), ctx);
- emit(ARM_LSL_I(r_X, r_X, 2), ctx);
- break;
- case BPF_ST:
- ctx->seen |= SEEN_MEM_WORD(k);
- emit(ARM_STR_I(r_A, ARM_SP, SCRATCH_OFF(k)), ctx);
- break;
- case BPF_STX:
- update_on_xread(ctx);
- ctx->seen |= SEEN_MEM_WORD(k);
- emit(ARM_STR_I(r_X, ARM_SP, SCRATCH_OFF(k)), ctx);
- break;
- case BPF_ALU | BPF_ADD | BPF_K:
- /* A += K */
- OP_IMM3(ARM_ADD, r_A, r_A, k, ctx);
- break;
- case BPF_ALU | BPF_ADD | BPF_X:
- update_on_xread(ctx);
- emit(ARM_ADD_R(r_A, r_A, r_X), ctx);
- break;
- case BPF_ALU | BPF_SUB | BPF_K:
- /* A -= K */
- OP_IMM3(ARM_SUB, r_A, r_A, k, ctx);
- break;
- case BPF_ALU | BPF_SUB | BPF_X:
- update_on_xread(ctx);
- emit(ARM_SUB_R(r_A, r_A, r_X), ctx);
- break;
- case BPF_ALU | BPF_MUL | BPF_K:
- /* A *= K */
- emit_mov_i(r_scratch, k, ctx);
- emit(ARM_MUL(r_A, r_A, r_scratch), ctx);
- break;
- case BPF_ALU | BPF_MUL | BPF_X:
- update_on_xread(ctx);
- emit(ARM_MUL(r_A, r_A, r_X), ctx);
+ emit_a32_mov_i64(is64, tmp2, imm, false, ctx);
+ emit_a32_mul_r64(dst, tmp2, dstk, false, ctx);
break;
- case BPF_ALU | BPF_DIV | BPF_K:
- if (k == 1)
- break;
- emit_mov_i(r_scratch, k, ctx);
- emit_udivmod(r_A, r_A, r_scratch, ctx, BPF_DIV);
- break;
- case BPF_ALU | BPF_DIV | BPF_X:
- update_on_xread(ctx);
- emit(ARM_CMP_I(r_X, 0), ctx);
- emit_err_ret(ARM_COND_EQ, ctx);
- emit_udivmod(r_A, r_A, r_X, ctx, BPF_DIV);
+ }
+ break;
+ /* dst = htole(dst) */
+ /* dst = htobe(dst) */
+ case BPF_ALU | BPF_END | BPF_FROM_LE:
+ case BPF_ALU | BPF_END | BPF_FROM_BE:
+ rd = dstk ? tmp[0] : dst_hi;
+ rt = dstk ? tmp[1] : dst_lo;
+ if (dstk) {
+ emit(ARM_LDR_I(rt, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ }
+ if (BPF_SRC(code) == BPF_FROM_LE)
+ goto emit_bswap_uxt;
+ switch (imm) {
+ case 16:
+ emit_rev16(rt, rt, ctx);
+ goto emit_bswap_uxt;
+ case 32:
+ emit_rev32(rt, rt, ctx);
+ goto emit_bswap_uxt;
+ case 64:
+ /* Because of the usage of ARM_LR */
+ ctx->seen |= SEEN_CALL;
+ emit_rev32(ARM_LR, rt, ctx);
+ emit_rev32(rt, rd, ctx);
+ emit(ARM_MOV_R(rd, ARM_LR), ctx);
break;
- case BPF_ALU | BPF_MOD | BPF_K:
- if (k == 1) {
- emit_mov_i(r_A, 0, ctx);
- break;
- }
- emit_mov_i(r_scratch, k, ctx);
- emit_udivmod(r_A, r_A, r_scratch, ctx, BPF_MOD);
+ }
+ goto exit;
+emit_bswap_uxt:
+ switch (imm) {
+ case 16:
+ /* zero-extend 16 bits into 64 bits */
+#if __LINUX_ARM_ARCH__ < 6
+ emit_a32_mov_i(tmp2[1], 0xffff, false, ctx);
+ emit(ARM_AND_R(rt, rt, tmp2[1]), ctx);
+#else /* ARMv6+ */
+ emit(ARM_UXTH(rt, rt), ctx);
+#endif
+ emit(ARM_EOR_R(rd, rd, rd), ctx);
break;
- case BPF_ALU | BPF_MOD | BPF_X:
- update_on_xread(ctx);
- emit(ARM_CMP_I(r_X, 0), ctx);
- emit_err_ret(ARM_COND_EQ, ctx);
- emit_udivmod(r_A, r_A, r_X, ctx, BPF_MOD);
+ case 32:
+ /* zero-extend 32 bits into 64 bits */
+ emit(ARM_EOR_R(rd, rd, rd), ctx);
break;
- case BPF_ALU | BPF_OR | BPF_K:
- /* A |= K */
- OP_IMM3(ARM_ORR, r_A, r_A, k, ctx);
+ case 64:
+ /* nop */
break;
- case BPF_ALU | BPF_OR | BPF_X:
- update_on_xread(ctx);
- emit(ARM_ORR_R(r_A, r_A, r_X), ctx);
+ }
+exit:
+ if (dstk) {
+ emit(ARM_STR_I(rt, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_STR_I(rd, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ }
+ break;
+ /* dst = imm64 */
+ case BPF_LD | BPF_IMM | BPF_DW:
+ {
+ const struct bpf_insn insn1 = insn[1];
+ u32 hi, lo = imm;
+
+ hi = insn1.imm;
+ emit_a32_mov_i(dst_lo, lo, dstk, ctx);
+ emit_a32_mov_i(dst_hi, hi, dstk, ctx);
+
+ return 1;
+ }
+ /* LDX: dst = *(size *)(src + off) */
+ case BPF_LDX | BPF_MEM | BPF_W:
+ case BPF_LDX | BPF_MEM | BPF_H:
+ case BPF_LDX | BPF_MEM | BPF_B:
+ case BPF_LDX | BPF_MEM | BPF_DW:
+ rn = sstk ? tmp2[1] : src_lo;
+ if (sstk)
+ emit(ARM_LDR_I(rn, ARM_SP, STACK_VAR(src_lo)), ctx);
+ switch (BPF_SIZE(code)) {
+ case BPF_W:
+ /* Load a Word */
+ case BPF_H:
+ /* Load a Half-Word */
+ case BPF_B:
+ /* Load a Byte */
+ emit_ldx_r(dst_lo, rn, dstk, off, ctx, BPF_SIZE(code));
+ emit_a32_mov_i(dst_hi, 0, dstk, ctx);
break;
- case BPF_ALU | BPF_XOR | BPF_K:
- /* A ^= K; */
- OP_IMM3(ARM_EOR, r_A, r_A, k, ctx);
+ case BPF_DW:
+ /* Load a double word */
+ emit_ldx_r(dst_lo, rn, dstk, off, ctx, BPF_W);
+ emit_ldx_r(dst_hi, rn, dstk, off+4, ctx, BPF_W);
break;
- case BPF_ANC | SKF_AD_ALU_XOR_X:
- case BPF_ALU | BPF_XOR | BPF_X:
- /* A ^= X */
- update_on_xread(ctx);
- emit(ARM_EOR_R(r_A, r_A, r_X), ctx);
+ }
+ break;
+ /* R0 = ntohx(*(size *)(((struct sk_buff *)R6)->data + imm)) */
+ case BPF_LD | BPF_ABS | BPF_W:
+ case BPF_LD | BPF_ABS | BPF_H:
+ case BPF_LD | BPF_ABS | BPF_B:
+ /* R0 = ntohx(*(size *)(((struct sk_buff *)R6)->data + src + imm)) */
+ case BPF_LD | BPF_IND | BPF_W:
+ case BPF_LD | BPF_IND | BPF_H:
+ case BPF_LD | BPF_IND | BPF_B:
+ {
+ const u8 r4 = bpf2a32[BPF_REG_6][1]; /* r4 = ptr to sk_buff */
+ const u8 r0 = bpf2a32[BPF_REG_0][1]; /*r0: struct sk_buff *skb*/
+ /* rtn value */
+ const u8 r1 = bpf2a32[BPF_REG_0][0]; /* r1: int k */
+ const u8 r2 = bpf2a32[BPF_REG_1][1]; /* r2: unsigned int size */
+ const u8 r3 = bpf2a32[BPF_REG_1][0]; /* r3: void *buffer */
+ const u8 r6 = bpf2a32[TMP_REG_1][1]; /* r6: void *(*func)(..) */
+ int size;
+
+ /* Setting up first argument */
+ emit(ARM_MOV_R(r0, r4), ctx);
+
+ /* Setting up second argument */
+ emit_a32_mov_i(r1, imm, false, ctx);
+ if (BPF_MODE(code) == BPF_IND)
+ emit_a32_alu_r(r1, src_lo, false, sstk, ctx,
+ false, false, BPF_ADD);
+
+ /* Setting up third argument */
+ switch (BPF_SIZE(code)) {
+ case BPF_W:
+ size = 4;
break;
- case BPF_ALU | BPF_AND | BPF_K:
- /* A &= K */
- OP_IMM3(ARM_AND, r_A, r_A, k, ctx);
+ case BPF_H:
+ size = 2;
break;
- case BPF_ALU | BPF_AND | BPF_X:
- update_on_xread(ctx);
- emit(ARM_AND_R(r_A, r_A, r_X), ctx);
+ case BPF_B:
+ size = 1;
break;
- case BPF_ALU | BPF_LSH | BPF_K:
- if (unlikely(k > 31))
- return -1;
- emit(ARM_LSL_I(r_A, r_A, k), ctx);
+ default:
+ return -EINVAL;
+ }
+ emit_a32_mov_i(r2, size, false, ctx);
+
+ /* Setting up fourth argument */
+ emit(ARM_ADD_I(r3, ARM_SP, imm8m(SKB_BUFFER)), ctx);
+
+ /* Setting up function pointer to call */
+ emit_a32_mov_i(r6, (unsigned int)bpf_load_pointer, false, ctx);
+ emit_blx_r(r6, ctx);
+
+ emit(ARM_EOR_R(r1, r1, r1), ctx);
+ /* Check if return address is NULL or not.
+ * if NULL then jump to epilogue
+ * else continue to load the value from retn address
+ */
+ emit(ARM_CMP_I(r0, 0), ctx);
+ jmp_offset = epilogue_offset(ctx);
+ check_imm24(jmp_offset);
+ _emit(ARM_COND_EQ, ARM_B(jmp_offset), ctx);
+
+ /* Load value from the address */
+ switch (BPF_SIZE(code)) {
+ case BPF_W:
+ emit(ARM_LDR_I(r0, r0, 0), ctx);
+ emit_rev32(r0, r0, ctx);
break;
- case BPF_ALU | BPF_LSH | BPF_X:
- update_on_xread(ctx);
- emit(ARM_LSL_R(r_A, r_A, r_X), ctx);
+ case BPF_H:
+ emit(ARM_LDRH_I(r0, r0, 0), ctx);
+ emit_rev16(r0, r0, ctx);
break;
- case BPF_ALU | BPF_RSH | BPF_K:
- if (unlikely(k > 31))
- return -1;
- if (k)
- emit(ARM_LSR_I(r_A, r_A, k), ctx);
+ case BPF_B:
+ emit(ARM_LDRB_I(r0, r0, 0), ctx);
+ /* No need to reverse */
break;
- case BPF_ALU | BPF_RSH | BPF_X:
- update_on_xread(ctx);
- emit(ARM_LSR_R(r_A, r_A, r_X), ctx);
+ }
+ break;
+ }
+ /* ST: *(size *)(dst + off) = imm */
+ case BPF_ST | BPF_MEM | BPF_W:
+ case BPF_ST | BPF_MEM | BPF_H:
+ case BPF_ST | BPF_MEM | BPF_B:
+ case BPF_ST | BPF_MEM | BPF_DW:
+ switch (BPF_SIZE(code)) {
+ case BPF_DW:
+ /* Sign-extend immediate value into temp reg */
+ emit_a32_mov_i64(true, tmp2, imm, false, ctx);
+ emit_str_r(dst_lo, tmp2[1], dstk, off, ctx, BPF_W);
+ emit_str_r(dst_lo, tmp2[0], dstk, off+4, ctx, BPF_W);
break;
- case BPF_ALU | BPF_NEG:
- /* A = -A */
- emit(ARM_RSB_I(r_A, r_A, 0), ctx);
+ case BPF_W:
+ case BPF_H:
+ case BPF_B:
+ emit_a32_mov_i(tmp2[1], imm, false, ctx);
+ emit_str_r(dst_lo, tmp2[1], dstk, off, ctx,
+ BPF_SIZE(code));
break;
- case BPF_JMP | BPF_JA:
- /* pc += K */
- emit(ARM_B(b_imm(i + k + 1, ctx)), ctx);
+ }
+ break;
+ /* STX XADD: lock *(u32 *)(dst + off) += src */
+ case BPF_STX | BPF_XADD | BPF_W:
+ /* STX XADD: lock *(u64 *)(dst + off) += src */
+ case BPF_STX | BPF_XADD | BPF_DW:
+ goto notyet;
+ /* STX: *(size *)(dst + off) = src */
+ case BPF_STX | BPF_MEM | BPF_W:
+ case BPF_STX | BPF_MEM | BPF_H:
+ case BPF_STX | BPF_MEM | BPF_B:
+ case BPF_STX | BPF_MEM | BPF_DW:
+ {
+ u8 sz = BPF_SIZE(code);
+
+ rn = sstk ? tmp2[1] : src_lo;
+ rm = sstk ? tmp2[0] : src_hi;
+ if (sstk) {
+ emit(ARM_LDR_I(rn, ARM_SP, STACK_VAR(src_lo)), ctx);
+ emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(src_hi)), ctx);
+ }
+
+ /* Store the value */
+ if (BPF_SIZE(code) == BPF_DW) {
+ emit_str_r(dst_lo, rn, dstk, off, ctx, BPF_W);
+ emit_str_r(dst_lo, rm, dstk, off+4, ctx, BPF_W);
+ } else {
+ emit_str_r(dst_lo, rn, dstk, off, ctx, sz);
+ }
+ break;
+ }
+ /* PC += off if dst == src */
+ /* PC += off if dst > src */
+ /* PC += off if dst >= src */
+ /* PC += off if dst < src */
+ /* PC += off if dst <= src */
+ /* PC += off if dst != src */
+ /* PC += off if dst > src (signed) */
+ /* PC += off if dst >= src (signed) */
+ /* PC += off if dst < src (signed) */
+ /* PC += off if dst <= src (signed) */
+ /* PC += off if dst & src */
+ case BPF_JMP | BPF_JEQ | BPF_X:
+ case BPF_JMP | BPF_JGT | BPF_X:
+ case BPF_JMP | BPF_JGE | BPF_X:
+ case BPF_JMP | BPF_JNE | BPF_X:
+ case BPF_JMP | BPF_JSGT | BPF_X:
+ case BPF_JMP | BPF_JSGE | BPF_X:
+ case BPF_JMP | BPF_JSET | BPF_X:
+ case BPF_JMP | BPF_JLE | BPF_X:
+ case BPF_JMP | BPF_JLT | BPF_X:
+ case BPF_JMP | BPF_JSLT | BPF_X:
+ case BPF_JMP | BPF_JSLE | BPF_X:
+ /* Setup source registers */
+ rm = sstk ? tmp2[0] : src_hi;
+ rn = sstk ? tmp2[1] : src_lo;
+ if (sstk) {
+ emit(ARM_LDR_I(rn, ARM_SP, STACK_VAR(src_lo)), ctx);
+ emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(src_hi)), ctx);
+ }
+ goto go_jmp;
+ /* PC += off if dst == imm */
+ /* PC += off if dst > imm */
+ /* PC += off if dst >= imm */
+ /* PC += off if dst < imm */
+ /* PC += off if dst <= imm */
+ /* PC += off if dst != imm */
+ /* PC += off if dst > imm (signed) */
+ /* PC += off if dst >= imm (signed) */
+ /* PC += off if dst < imm (signed) */
+ /* PC += off if dst <= imm (signed) */
+ /* PC += off if dst & imm */
+ case BPF_JMP | BPF_JEQ | BPF_K:
+ case BPF_JMP | BPF_JGT | BPF_K:
+ case BPF_JMP | BPF_JGE | BPF_K:
+ case BPF_JMP | BPF_JNE | BPF_K:
+ case BPF_JMP | BPF_JSGT | BPF_K:
+ case BPF_JMP | BPF_JSGE | BPF_K:
+ case BPF_JMP | BPF_JSET | BPF_K:
+ case BPF_JMP | BPF_JLT | BPF_K:
+ case BPF_JMP | BPF_JLE | BPF_K:
+ case BPF_JMP | BPF_JSLT | BPF_K:
+ case BPF_JMP | BPF_JSLE | BPF_K:
+ if (off == 0)
break;
- case BPF_JMP | BPF_JEQ | BPF_K:
- /* pc += (A == K) ? pc->jt : pc->jf */
- condt = ARM_COND_EQ;
- goto cmp_imm;
- case BPF_JMP | BPF_JGT | BPF_K:
- /* pc += (A > K) ? pc->jt : pc->jf */
- condt = ARM_COND_HI;
- goto cmp_imm;
- case BPF_JMP | BPF_JGE | BPF_K:
- /* pc += (A >= K) ? pc->jt : pc->jf */
- condt = ARM_COND_HS;
-cmp_imm:
- imm12 = imm8m(k);
- if (imm12 < 0) {
- emit_mov_i_no8m(r_scratch, k, ctx);
- emit(ARM_CMP_R(r_A, r_scratch), ctx);
- } else {
- emit(ARM_CMP_I(r_A, imm12), ctx);
- }
-cond_jump:
- if (inst->jt)
- _emit(condt, ARM_B(b_imm(i + inst->jt + 1,
- ctx)), ctx);
- if (inst->jf)
- _emit(condt ^ 1, ARM_B(b_imm(i + inst->jf + 1,
- ctx)), ctx);
+ rm = tmp2[0];
+ rn = tmp2[1];
+ /* Sign-extend immediate value */
+ emit_a32_mov_i64(true, tmp2, imm, false, ctx);
+go_jmp:
+ /* Setup destination register */
+ rd = dstk ? tmp[0] : dst_hi;
+ rt = dstk ? tmp[1] : dst_lo;
+ if (dstk) {
+ emit(ARM_LDR_I(rt, ARM_SP, STACK_VAR(dst_lo)), ctx);
+ emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_hi)), ctx);
+ }
+
+ /* Check for the condition */
+ emit_ar_r(rd, rt, rm, rn, ctx, BPF_OP(code));
+
+ /* Setup JUMP instruction */
+ jmp_offset = bpf2a32_offset(i+off, i, ctx);
+ switch (BPF_OP(code)) {
+ case BPF_JNE:
+ case BPF_JSET:
+ _emit(ARM_COND_NE, ARM_B(jmp_offset), ctx);
break;
- case BPF_JMP | BPF_JEQ | BPF_X:
- /* pc += (A == X) ? pc->jt : pc->jf */
- condt = ARM_COND_EQ;
- goto cmp_x;
- case BPF_JMP | BPF_JGT | BPF_X:
- /* pc += (A > X) ? pc->jt : pc->jf */
- condt = ARM_COND_HI;
- goto cmp_x;
- case BPF_JMP | BPF_JGE | BPF_X:
- /* pc += (A >= X) ? pc->jt : pc->jf */
- condt = ARM_COND_CS;
-cmp_x:
- update_on_xread(ctx);
- emit(ARM_CMP_R(r_A, r_X), ctx);
- goto cond_jump;
- case BPF_JMP | BPF_JSET | BPF_K:
- /* pc += (A & K) ? pc->jt : pc->jf */
- condt = ARM_COND_NE;
- /* not set iff all zeroes iff Z==1 iff EQ */
-
- imm12 = imm8m(k);
- if (imm12 < 0) {
- emit_mov_i_no8m(r_scratch, k, ctx);
- emit(ARM_TST_R(r_A, r_scratch), ctx);
- } else {
- emit(ARM_TST_I(r_A, imm12), ctx);
- }
- goto cond_jump;
- case BPF_JMP | BPF_JSET | BPF_X:
- /* pc += (A & X) ? pc->jt : pc->jf */
- update_on_xread(ctx);
- condt = ARM_COND_NE;
- emit(ARM_TST_R(r_A, r_X), ctx);
- goto cond_jump;
- case BPF_RET | BPF_A:
- emit(ARM_MOV_R(ARM_R0, r_A), ctx);
- goto b_epilogue;
- case BPF_RET | BPF_K:
- if ((k == 0) && (ctx->ret0_fp_idx < 0))
- ctx->ret0_fp_idx = i;
- emit_mov_i(ARM_R0, k, ctx);
-b_epilogue:
- if (i != ctx->skf->len - 1)
- emit(ARM_B(b_imm(prog->len, ctx)), ctx);
+ case BPF_JEQ:
+ _emit(ARM_COND_EQ, ARM_B(jmp_offset), ctx);
break;
- case BPF_MISC | BPF_TAX:
- /* X = A */
- ctx->seen |= SEEN_X;
- emit(ARM_MOV_R(r_X, r_A), ctx);
+ case BPF_JGT:
+ _emit(ARM_COND_HI, ARM_B(jmp_offset), ctx);
break;
- case BPF_MISC | BPF_TXA:
- /* A = X */
- update_on_xread(ctx);
- emit(ARM_MOV_R(r_A, r_X), ctx);
+ case BPF_JGE:
+ _emit(ARM_COND_CS, ARM_B(jmp_offset), ctx);
break;
- case BPF_ANC | SKF_AD_PROTOCOL:
- /* A = ntohs(skb->protocol) */
- ctx->seen |= SEEN_SKB;
- BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff,
- protocol) != 2);
- off = offsetof(struct sk_buff, protocol);
- emit(ARM_LDRH_I(r_scratch, r_skb, off), ctx);
- emit_swap16(r_A, r_scratch, ctx);
+ case BPF_JSGT:
+ _emit(ARM_COND_LT, ARM_B(jmp_offset), ctx);
break;
- case BPF_ANC | SKF_AD_CPU:
- /* r_scratch = current_thread_info() */
- OP_IMM3(ARM_BIC, r_scratch, ARM_SP, THREAD_SIZE - 1, ctx);
- /* A = current_thread_info()->cpu */
- BUILD_BUG_ON(FIELD_SIZEOF(struct thread_info, cpu) != 4);
- off = offsetof(struct thread_info, cpu);
- emit(ARM_LDR_I(r_A, r_scratch, off), ctx);
+ case BPF_JSGE:
+ _emit(ARM_COND_GE, ARM_B(jmp_offset), ctx);
break;
- case BPF_ANC | SKF_AD_IFINDEX:
- case BPF_ANC | SKF_AD_HATYPE:
- /* A = skb->dev->ifindex */
- /* A = skb->dev->type */
- ctx->seen |= SEEN_SKB;
- off = offsetof(struct sk_buff, dev);
- emit(ARM_LDR_I(r_scratch, r_skb, off), ctx);
-
- emit(ARM_CMP_I(r_scratch, 0), ctx);
- emit_err_ret(ARM_COND_EQ, ctx);
-
- BUILD_BUG_ON(FIELD_SIZEOF(struct net_device,
- ifindex) != 4);
- BUILD_BUG_ON(FIELD_SIZEOF(struct net_device,
- type) != 2);
-
- if (code == (BPF_ANC | SKF_AD_IFINDEX)) {
- off = offsetof(struct net_device, ifindex);
- emit(ARM_LDR_I(r_A, r_scratch, off), ctx);
- } else {
- /*
- * offset of field "type" in "struct
- * net_device" is above what can be
- * used in the ldrh rd, [rn, #imm]
- * instruction, so load the offset in
- * a register and use ldrh rd, [rn, rm]
- */
- off = offsetof(struct net_device, type);
- emit_mov_i(ARM_R3, off, ctx);
- emit(ARM_LDRH_R(r_A, r_scratch, ARM_R3), ctx);
- }
+ case BPF_JLE:
+ _emit(ARM_COND_LS, ARM_B(jmp_offset), ctx);
break;
- case BPF_ANC | SKF_AD_MARK:
- ctx->seen |= SEEN_SKB;
- BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);
- off = offsetof(struct sk_buff, mark);
- emit(ARM_LDR_I(r_A, r_skb, off), ctx);
+ case BPF_JLT:
+ _emit(ARM_COND_CC, ARM_B(jmp_offset), ctx);
break;
- case BPF_ANC | SKF_AD_RXHASH:
- ctx->seen |= SEEN_SKB;
- BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4);
- off = offsetof(struct sk_buff, hash);
- emit(ARM_LDR_I(r_A, r_skb, off), ctx);
+ case BPF_JSLT:
+ _emit(ARM_COND_LT, ARM_B(jmp_offset), ctx);
break;
- case BPF_ANC | SKF_AD_VLAN_TAG:
- case BPF_ANC | SKF_AD_VLAN_TAG_PRESENT:
- ctx->seen |= SEEN_SKB;
- BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2);
- off = offsetof(struct sk_buff, vlan_tci);
- emit(ARM_LDRH_I(r_A, r_skb, off), ctx);
- if (code == (BPF_ANC | SKF_AD_VLAN_TAG))
- OP_IMM3(ARM_AND, r_A, r_A, ~VLAN_TAG_PRESENT, ctx);
- else {
- OP_IMM3(ARM_LSR, r_A, r_A, 12, ctx);
- OP_IMM3(ARM_AND, r_A, r_A, 0x1, ctx);
- }
+ case BPF_JSLE:
+ _emit(ARM_COND_GE, ARM_B(jmp_offset), ctx);
break;
- case BPF_ANC | SKF_AD_PKTTYPE:
- ctx->seen |= SEEN_SKB;
- BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff,
- __pkt_type_offset[0]) != 1);
- off = PKT_TYPE_OFFSET();
- emit(ARM_LDRB_I(r_A, r_skb, off), ctx);
- emit(ARM_AND_I(r_A, r_A, PKT_TYPE_MAX), ctx);
-#ifdef __BIG_ENDIAN_BITFIELD
- emit(ARM_LSR_I(r_A, r_A, 5), ctx);
-#endif
+ }
+ break;
+ /* JMP OFF */
+ case BPF_JMP | BPF_JA:
+ {
+ if (off == 0)
break;
- case BPF_ANC | SKF_AD_QUEUE:
- ctx->seen |= SEEN_SKB;
- 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(ARM_LDRH_I(r_A, r_skb, off), ctx);
+ jmp_offset = bpf2a32_offset(i+off, i, ctx);
+ check_imm24(jmp_offset);
+ emit(ARM_B(jmp_offset), ctx);
+ break;
+ }
+ /* tail call */
+ case BPF_JMP | BPF_TAIL_CALL:
+ if (emit_bpf_tail_call(ctx))
+ return -EFAULT;
+ break;
+ /* function call */
+ case BPF_JMP | BPF_CALL:
+ {
+ const u8 *r0 = bpf2a32[BPF_REG_0];
+ const u8 *r1 = bpf2a32[BPF_REG_1];
+ const u8 *r2 = bpf2a32[BPF_REG_2];
+ const u8 *r3 = bpf2a32[BPF_REG_3];
+ const u8 *r4 = bpf2a32[BPF_REG_4];
+ const u8 *r5 = bpf2a32[BPF_REG_5];
+ const u32 func = (u32)__bpf_call_base + (u32)imm;
+
+ emit_a32_mov_r64(true, r0, r1, false, false, ctx);
+ emit_a32_mov_r64(true, r1, r2, false, true, ctx);
+ emit_push_r64(r5, 0, ctx);
+ emit_push_r64(r4, 8, ctx);
+ emit_push_r64(r3, 16, ctx);
+
+ emit_a32_mov_i(tmp[1], func, false, ctx);
+ emit_blx_r(tmp[1], ctx);
+
+ emit(ARM_ADD_I(ARM_SP, ARM_SP, imm8m(24)), ctx); // callee clean
+ break;
+ }
+ /* function return */
+ case BPF_JMP | BPF_EXIT:
+ /* Optimization: when last instruction is EXIT
+ * simply fallthrough to epilogue.
+ */
+ if (i == ctx->prog->len - 1)
break;
- case BPF_ANC | SKF_AD_PAY_OFFSET:
- ctx->seen |= SEEN_SKB | SEEN_CALL;
+ jmp_offset = epilogue_offset(ctx);
+ check_imm24(jmp_offset);
+ emit(ARM_B(jmp_offset), ctx);
+ break;
+notyet:
+ pr_info_once("*** NOT YET: opcode %02x ***\n", code);
+ return -EFAULT;
+ default:
+ pr_err_once("unknown opcode %02x\n", code);
+ return -EINVAL;
+ }
- emit(ARM_MOV_R(ARM_R0, r_skb), ctx);
- emit_mov_i(ARM_R3, (unsigned int)skb_get_poff, ctx);
- emit_blx_r(ARM_R3, ctx);
- emit(ARM_MOV_R(r_A, ARM_R0), ctx);
- break;
- case BPF_LDX | BPF_W | BPF_ABS:
- /*
- * load a 32bit word from struct seccomp_data.
- * seccomp_check_filter() will already have checked
- * that k is 32bit aligned and lies within the
- * struct seccomp_data.
- */
- ctx->seen |= SEEN_SKB;
- emit(ARM_LDR_I(r_A, r_skb, k), ctx);
- break;
- default:
- return -1;
+ if (ctx->flags & FLAG_IMM_OVERFLOW)
+ /*
+ * this instruction generated an overflow when
+ * trying to access the literal pool, so
+ * delegate this filter to the kernel interpreter.
+ */
+ return -1;
+ return 0;
+}
+
+static int build_body(struct jit_ctx *ctx)
+{
+ const struct bpf_prog *prog = ctx->prog;
+ unsigned int i;
+
+ for (i = 0; i < prog->len; i++) {
+ const struct bpf_insn *insn = &(prog->insnsi[i]);
+ int ret;
+
+ ret = build_insn(insn, ctx);
+
+ /* It's used with loading the 64 bit immediate value. */
+ if (ret > 0) {
+ i++;
+ if (ctx->target == NULL)
+ ctx->offsets[i] = ctx->idx;
+ continue;
}
- if (ctx->flags & FLAG_IMM_OVERFLOW)
- /*
- * this instruction generated an overflow when
- * trying to access the literal pool, so
- * delegate this filter to the kernel interpreter.
- */
- return -1;
+ if (ctx->target == NULL)
+ ctx->offsets[i] = ctx->idx;
+
+ /* If unsuccesfull, return with error code */
+ if (ret)
+ return ret;
}
+ return 0;
+}
- /* compute offsets only during the first pass */
- if (ctx->target == NULL)
- ctx->offsets[i] = ctx->idx * 4;
+static int validate_code(struct jit_ctx *ctx)
+{
+ int i;
+
+ for (i = 0; i < ctx->idx; i++) {
+ if (ctx->target[i] == __opcode_to_mem_arm(ARM_INST_UDF))
+ return -1;
+ }
return 0;
}
+void bpf_jit_compile(struct bpf_prog *prog)
+{
+ /* Nothing to do here. We support Internal BPF. */
+}
-void bpf_jit_compile(struct bpf_prog *fp)
+struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
{
+ struct bpf_prog *tmp, *orig_prog = prog;
struct bpf_binary_header *header;
+ bool tmp_blinded = false;
struct jit_ctx ctx;
- unsigned tmp_idx;
- unsigned alloc_size;
- u8 *target_ptr;
+ unsigned int tmp_idx;
+ unsigned int image_size;
+ u8 *image_ptr;
+ /* If BPF JIT was not enabled then we must fall back to
+ * the interpreter.
+ */
if (!bpf_jit_enable)
- return;
+ return orig_prog;
- memset(&ctx, 0, sizeof(ctx));
- ctx.skf = fp;
- ctx.ret0_fp_idx = -1;
+ /* If constant blinding was enabled and we failed during blinding
+ * then we must fall back to the interpreter. Otherwise, we save
+ * the new JITed code.
+ */
+ tmp = bpf_jit_blind_constants(prog);
- ctx.offsets = kzalloc(4 * (ctx.skf->len + 1), GFP_KERNEL);
- if (ctx.offsets == NULL)
- return;
+ if (IS_ERR(tmp))
+ return orig_prog;
+ if (tmp != prog) {
+ tmp_blinded = true;
+ prog = tmp;
+ }
- /* fake pass to fill in the ctx->seen */
- if (unlikely(build_body(&ctx)))
+ memset(&ctx, 0, sizeof(ctx));
+ ctx.prog = prog;
+
+ /* Not able to allocate memory for offsets[] , then
+ * we must fall back to the interpreter
+ */
+ ctx.offsets = kcalloc(prog->len, sizeof(int), GFP_KERNEL);
+ if (ctx.offsets == NULL) {
+ prog = orig_prog;
goto out;
+ }
+
+ /* 1) fake pass to find in the length of the JITed code,
+ * to compute ctx->offsets and other context variables
+ * needed to compute final JITed code.
+ * Also, calculate random starting pointer/start of JITed code
+ * which is prefixed by random number of fault instructions.
+ *
+ * If the first pass fails then there is no chance of it
+ * being successful in the second pass, so just fall back
+ * to the interpreter.
+ */
+ if (build_body(&ctx)) {
+ prog = orig_prog;
+ goto out_off;
+ }
tmp_idx = ctx.idx;
build_prologue(&ctx);
ctx.prologue_bytes = (ctx.idx - tmp_idx) * 4;
+ ctx.epilogue_offset = ctx.idx;
+
#if __LINUX_ARM_ARCH__ < 7
tmp_idx = ctx.idx;
build_epilogue(&ctx);
ctx.idx += ctx.imm_count;
if (ctx.imm_count) {
- ctx.imms = kzalloc(4 * ctx.imm_count, GFP_KERNEL);
- if (ctx.imms == NULL)
- goto out;
+ ctx.imms = kcalloc(ctx.imm_count, sizeof(u32), GFP_KERNEL);
+ if (ctx.imms == NULL) {
+ prog = orig_prog;
+ goto out_off;
+ }
}
#else
- /* there's nothing after the epilogue on ARMv7 */
+ /* there's nothing about the epilogue on ARMv7 */
build_epilogue(&ctx);
#endif
- alloc_size = 4 * ctx.idx;
- header = bpf_jit_binary_alloc(alloc_size, &target_ptr,
- 4, jit_fill_hole);
- if (header == NULL)
- goto out;
+ /* Now we can get the actual image size of the JITed arm code.
+ * Currently, we are not considering the THUMB-2 instructions
+ * for jit, although it can decrease the size of the image.
+ *
+ * As each arm instruction is of length 32bit, we are translating
+ * number of JITed intructions into the size required to store these
+ * JITed code.
+ */
+ image_size = sizeof(u32) * ctx.idx;
- ctx.target = (u32 *) target_ptr;
+ /* Now we know the size of the structure to make */
+ header = bpf_jit_binary_alloc(image_size, &image_ptr,
+ sizeof(u32), jit_fill_hole);
+ /* Not able to allocate memory for the structure then
+ * we must fall back to the interpretation
+ */
+ if (header == NULL) {
+ prog = orig_prog;
+ goto out_imms;
+ }
+
+ /* 2.) Actual pass to generate final JIT code */
+ ctx.target = (u32 *) image_ptr;
ctx.idx = 0;
build_prologue(&ctx);
+
+ /* If building the body of the JITed code fails somehow,
+ * we fall back to the interpretation.
+ */
if (build_body(&ctx) < 0) {
-#if __LINUX_ARM_ARCH__ < 7
- if (ctx.imm_count)
- kfree(ctx.imms);
-#endif
+ image_ptr = NULL;
bpf_jit_binary_free(header);
- goto out;
+ prog = orig_prog;
+ goto out_imms;
}
build_epilogue(&ctx);
+ /* 3.) Extra pass to validate JITed Code */
+ if (validate_code(&ctx)) {
+ image_ptr = NULL;
+ bpf_jit_binary_free(header);
+ prog = orig_prog;
+ goto out_imms;
+ }
flush_icache_range((u32)header, (u32)(ctx.target + ctx.idx));
-#if __LINUX_ARM_ARCH__ < 7
- if (ctx.imm_count)
- kfree(ctx.imms);
-#endif
-
if (bpf_jit_enable > 1)
/* there are 2 passes here */
- bpf_jit_dump(fp->len, alloc_size, 2, ctx.target);
+ bpf_jit_dump(prog->len, image_size, 2, ctx.target);
set_memory_ro((unsigned long)header, header->pages);
- fp->bpf_func = (void *)ctx.target;
- fp->jited = 1;
-out:
+ prog->bpf_func = (void *)ctx.target;
+ prog->jited = 1;
+ prog->jited_len = image_size;
+
+out_imms:
+#if __LINUX_ARM_ARCH__ < 7
+ if (ctx.imm_count)
+ kfree(ctx.imms);
+#endif
+out_off:
kfree(ctx.offsets);
- return;
+out:
+ if (tmp_blinded)
+ bpf_jit_prog_release_other(prog, prog == orig_prog ?
+ tmp : orig_prog);
+ return prog;
}
-void bpf_jit_free(struct bpf_prog *fp)
-{
- unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK;
- struct bpf_binary_header *header = (void *)addr;
-
- if (!fp->jited)
- goto free_filter;
-
- set_memory_rw(addr, header->pages);
- bpf_jit_binary_free(header);
-
-free_filter:
- bpf_prog_unlock_free(fp);
-}
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff