diff options
author | David S. Miller <davem@davemloft.net> | 2018-01-20 04:59:33 +0100 |
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committer | David S. Miller <davem@davemloft.net> | 2018-01-20 04:59:33 +0100 |
commit | 8565d26bcb2ff6df646e946d2913fcf706d46b66 (patch) | |
tree | 21ffaccc3cbac5e558d51c20cfbecbfec86a02c4 /arch/arm/net | |
parent | Merge branch 'dsa-mv88e6xxx-ATU-VTU-irq-fixes' (diff) | |
parent | Merge tag 'trace-v4.15-rc4-3' of git://git.kernel.org/pub/scm/linux/kernel/gi... (diff) | |
download | linux-8565d26bcb2ff6df646e946d2913fcf706d46b66.tar.xz linux-8565d26bcb2ff6df646e946d2913fcf706d46b66.zip |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
The BPF verifier conflict was some minor contextual issue.
The TUN conflict was less trivial. Cong Wang fixed a memory leak of
tfile->tx_array in 'net'. This is an skb_array. But meanwhile in
net-next tun changed tfile->tx_arry into tfile->tx_ring which is a
ptr_ring.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/arm/net')
-rw-r--r-- | arch/arm/net/bpf_jit_32.c | 225 |
1 files changed, 111 insertions, 114 deletions
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index 4425189bb24c..a5edea07b8d5 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -27,14 +27,58 @@ int bpf_jit_enable __read_mostly; +/* + * eBPF prog stack layout: + * + * high + * original ARM_SP => +-----+ + * | | callee saved registers + * +-----+ <= (BPF_FP + SCRATCH_SIZE) + * | ... | eBPF JIT scratch space + * eBPF fp register => +-----+ + * (BPF_FP) | ... | eBPF prog stack + * +-----+ + * |RSVD | JIT scratchpad + * current ARM_SP => +-----+ <= (BPF_FP - STACK_SIZE + SCRATCH_SIZE) + * | | + * | ... | Function call stack + * | | + * +-----+ + * low + * + * The callee saved registers depends on whether frame pointers are enabled. + * With frame pointers (to be compliant with the ABI): + * + * high + * original ARM_SP => +------------------+ \ + * | pc | | + * current ARM_FP => +------------------+ } callee saved registers + * |r4-r8,r10,fp,ip,lr| | + * +------------------+ / + * low + * + * Without frame pointers: + * + * high + * original ARM_SP => +------------------+ + * | r4-r8,r10,fp,lr | callee saved registers + * current ARM_FP => +------------------+ + * low + * + * When popping registers off the stack at the end of a BPF function, we + * reference them via the current ARM_FP register. + */ +#define CALLEE_MASK (1 << ARM_R4 | 1 << ARM_R5 | 1 << ARM_R6 | \ + 1 << ARM_R7 | 1 << ARM_R8 | 1 << ARM_R10 | \ + 1 << ARM_FP) +#define CALLEE_PUSH_MASK (CALLEE_MASK | 1 << ARM_LR) +#define CALLEE_POP_MASK (CALLEE_MASK | 1 << ARM_PC) + #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) /* @@ -95,7 +139,6 @@ static const u8 bpf2a32[][2] = { * 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. @@ -110,7 +153,6 @@ struct jit_ctx { unsigned int idx; unsigned int prologue_bytes; unsigned int epilogue_offset; - u32 seen; u32 flags; u32 *offsets; u32 *target; @@ -179,8 +221,13 @@ static void jit_fill_hole(void *area, unsigned int size) *ptr++ = __opcode_to_mem_arm(ARM_INST_UDF); } -/* Stack must be multiples of 16 Bytes */ -#define STACK_ALIGN(sz) (((sz) + 3) & ~3) +#if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5) +/* EABI requires the stack to be aligned to 64-bit boundaries */ +#define STACK_ALIGNMENT 8 +#else +/* Stack must be aligned to 32-bit boundaries */ +#define STACK_ALIGNMENT 4 +#endif /* Stack space for BPF_REG_2, BPF_REG_3, BPF_REG_4, * BPF_REG_5, BPF_REG_7, BPF_REG_8, BPF_REG_9, @@ -194,7 +241,7 @@ static void jit_fill_hole(void *area, unsigned int size) + SCRATCH_SIZE + \ + 4 /* extra for skb_copy_bits buffer */) -#define STACK_SIZE STACK_ALIGN(_STACK_SIZE) +#define STACK_SIZE ALIGN(_STACK_SIZE, STACK_ALIGNMENT) /* Get the offset of eBPF REGISTERs stored on scratch space. */ #define STACK_VAR(off) (STACK_SIZE-off-4) @@ -285,16 +332,19 @@ static inline void emit_mov_i(const u8 rd, u32 val, struct jit_ctx *ctx) emit_mov_i_no8m(rd, val, ctx); } -static inline void emit_blx_r(u8 tgt_reg, struct jit_ctx *ctx) +static void emit_bx_r(u8 tgt_reg, struct jit_ctx *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); +} + +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); + emit_bx_r(tgt_reg, ctx); #else emit(ARM_BLX_R(tgt_reg), ctx); #endif @@ -354,7 +404,6 @@ static inline void emit_udivmod(u8 rd, u8 rm, u8 rn, struct jit_ctx *ctx, u8 op) } /* 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); @@ -620,8 +669,6 @@ static inline void emit_a32_lsh_r64(const u8 dst[], const u8 src[], bool dstk, /* 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(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); @@ -656,8 +703,6 @@ static inline void emit_a32_arsh_r64(const u8 dst[], const u8 src[], bool dstk, /* 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); @@ -692,8 +737,6 @@ static inline void emit_a32_lsr_r64(const u8 dst[], const u8 src[], bool dstk, /* 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); @@ -828,8 +871,6 @@ static inline void emit_a32_mul_r64(const u8 dst[], const u8 src[], bool dstk, /* 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); @@ -872,33 +913,53 @@ static inline void emit_str_r(const u8 dst, const u8 src, bool dstk, } /* 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){ +static inline void emit_ldx_r(const u8 dst[], const u8 src, bool dstk, + s32 off, struct jit_ctx *ctx, const u8 sz){ const u8 *tmp = bpf2a32[TMP_REG_1]; - u8 rd = dstk ? tmp[1] : dst; + const u8 *rd = dstk ? tmp : dst; u8 rm = src; + s32 off_max; - if (off) { + if (sz == BPF_H) + off_max = 0xff; + else + off_max = 0xfff; + + if (off < 0 || off > off_max) { emit_a32_mov_i(tmp[0], off, false, ctx); emit(ARM_ADD_R(tmp[0], tmp[0], src), ctx); rm = tmp[0]; + off = 0; + } else if (rd[1] == rm) { + emit(ARM_MOV_R(tmp[0], rm), ctx); + rm = tmp[0]; } switch (sz) { - case BPF_W: - /* Load a Word */ - emit(ARM_LDR_I(rd, rm, 0), ctx); + case BPF_B: + /* Load a Byte */ + emit(ARM_LDRB_I(rd[1], rm, off), ctx); + emit_a32_mov_i(dst[0], 0, dstk, ctx); break; case BPF_H: /* Load a HalfWord */ - emit(ARM_LDRH_I(rd, rm, 0), ctx); + emit(ARM_LDRH_I(rd[1], rm, off), ctx); + emit_a32_mov_i(dst[0], 0, dstk, ctx); break; - case BPF_B: - /* Load a Byte */ - emit(ARM_LDRB_I(rd, rm, 0), ctx); + case BPF_W: + /* Load a Word */ + emit(ARM_LDR_I(rd[1], rm, off), ctx); + emit_a32_mov_i(dst[0], 0, dstk, ctx); + break; + case BPF_DW: + /* Load a Double Word */ + emit(ARM_LDR_I(rd[1], rm, off), ctx); + emit(ARM_LDR_I(rd[0], rm, off + 4), ctx); break; } if (dstk) - emit(ARM_STR_I(rd, ARM_SP, STACK_VAR(dst)), ctx); + emit(ARM_STR_I(rd[1], ARM_SP, STACK_VAR(dst[1])), ctx); + if (dstk && sz == BPF_DW) + emit(ARM_STR_I(rd[0], ARM_SP, STACK_VAR(dst[0])), ctx); } /* Arithmatic Operation */ @@ -906,7 +967,6 @@ 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); @@ -945,7 +1005,7 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx) const u8 *tcc = bpf2a32[TCALL_CNT]; const int idx0 = ctx->idx; #define cur_offset (ctx->idx - idx0) -#define jmp_offset (out_offset - (cur_offset)) +#define jmp_offset (out_offset - (cur_offset) - 2) u32 off, lo, hi; /* if (index >= array->map.max_entries) @@ -956,7 +1016,7 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx) 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) */ + /* index is 32-bit for arrays */ 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); @@ -997,7 +1057,7 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx) 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); + emit_bx_r(tmp[1], ctx); /* out: */ if (out_offset == -1) @@ -1070,54 +1130,22 @@ static void build_prologue(struct jit_ctx *ctx) 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); + u16 reg_set = CALLEE_PUSH_MASK | 1 << ARM_IP | 1 << ARM_PC; + 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 - /* Check if call instruction exists in BPF body */ - if (ctx->seen & SEEN_CALL) - reg_set |= (1<<ARM_LR); - emit(ARM_PUSH(reg_set), ctx); + emit(ARM_PUSH(CALLEE_PUSH_MASK), ctx); + emit(ARM_MOV_R(ARM_FP, ARM_SP), ctx); #endif /* Save frame pointer for later */ - emit(ARM_SUB_I(ARM_IP, sp, SCRATCH_SIZE), ctx); + emit(ARM_SUB_I(ARM_IP, ARM_SP, SCRATCH_SIZE), ctx); ctx->stack_size = imm8m(STACK_SIZE); @@ -1140,33 +1168,19 @@ static void build_prologue(struct jit_ctx *ctx) /* end of prologue */ } +/* restore callee saved registers. */ 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); + /* When using frame pointers, some additional registers need to + * be loaded. */ + u16 reg_set = CALLEE_POP_MASK | 1 << ARM_SP; + emit(ARM_SUB_I(ARM_SP, ARM_FP, hweight16(reg_set) * 4), ctx); 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); + emit(ARM_MOV_R(ARM_SP, ARM_FP), ctx); + emit(ARM_POP(CALLEE_POP_MASK), ctx); #endif } @@ -1394,8 +1408,6 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) 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); @@ -1448,22 +1460,7 @@ exit: 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_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; - } + emit_ldx_r(dst, rn, dstk, off, ctx, BPF_SIZE(code)); break; /* R0 = ntohx(*(size *)(((struct sk_buff *)R6)->data + imm)) */ case BPF_LD | BPF_ABS | BPF_W: |