diff options
author | Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | 2016-06-22 21:55:07 +0530 |
---|---|---|
committer | Michael Ellerman <mpe@ellerman.id.au> | 2016-06-24 15:17:57 +1000 |
commit | 156d0e290e969caba25f1851c52417c14d141b24 (patch) | |
tree | a232dcd99242656e3e935e44d0fa6649618f58ba /arch/powerpc/net | |
parent | 6ac0ba5a4f82b40b4f6b3a75e7e4f0a15a3d7b9b (diff) | |
download | linux-156d0e290e969caba25f1851c52417c14d141b24.tar.bz2 |
powerpc/ebpf/jit: Implement JIT compiler for extended BPF
PPC64 eBPF JIT compiler.
Enable with:
echo 1 > /proc/sys/net/core/bpf_jit_enable
or
echo 2 > /proc/sys/net/core/bpf_jit_enable
... to see the generated JIT code. This can further be processed with
tools/net/bpf_jit_disasm.
With CONFIG_TEST_BPF=m and 'modprobe test_bpf':
test_bpf: Summary: 305 PASSED, 0 FAILED, [297/297 JIT'ed]
... on both ppc64 BE and LE.
The details of the approach are documented through various comments in
the code.
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/net')
-rw-r--r-- | arch/powerpc/net/Makefile | 4 | ||||
-rw-r--r-- | arch/powerpc/net/bpf_jit.h | 53 | ||||
-rw-r--r-- | arch/powerpc/net/bpf_jit64.h | 102 | ||||
-rw-r--r-- | arch/powerpc/net/bpf_jit_asm64.S | 180 | ||||
-rw-r--r-- | arch/powerpc/net/bpf_jit_comp64.c | 954 |
5 files changed, 1292 insertions, 1 deletions
diff --git a/arch/powerpc/net/Makefile b/arch/powerpc/net/Makefile index 1306a58ac541..c1ff16a6eb51 100644 --- a/arch/powerpc/net/Makefile +++ b/arch/powerpc/net/Makefile @@ -1,4 +1,8 @@ # # Arch-specific network modules # +ifeq ($(CONFIG_PPC64),y) +obj-$(CONFIG_BPF_JIT) += bpf_jit_asm64.o bpf_jit_comp64.o +else obj-$(CONFIG_BPF_JIT) += bpf_jit_asm.o bpf_jit_comp.o +endif diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h index 313cfafde9bb..d5301b6f20d0 100644 --- a/arch/powerpc/net/bpf_jit.h +++ b/arch/powerpc/net/bpf_jit.h @@ -2,6 +2,7 @@ * bpf_jit.h: BPF JIT compiler for PPC * * Copyright 2011 Matt Evans <matt@ozlabs.org>, IBM Corporation + * 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License @@ -13,7 +14,9 @@ #ifndef __ASSEMBLY__ -#ifdef CONFIG_PPC64 +#include <asm/types.h> + +#ifdef PPC64_ELF_ABI_v1 #define FUNCTION_DESCR_SIZE 24 #else #define FUNCTION_DESCR_SIZE 0 @@ -52,6 +55,10 @@ ___PPC_RA(base) | IMM_L(i)) #define PPC_STWU(r, base, i) EMIT(PPC_INST_STWU | ___PPC_RS(r) | \ ___PPC_RA(base) | IMM_L(i)) +#define PPC_STH(r, base, i) EMIT(PPC_INST_STH | ___PPC_RS(r) | \ + ___PPC_RA(base) | IMM_L(i)) +#define PPC_STB(r, base, i) EMIT(PPC_INST_STB | ___PPC_RS(r) | \ + ___PPC_RA(base) | IMM_L(i)) #define PPC_LBZ(r, base, i) EMIT(PPC_INST_LBZ | ___PPC_RT(r) | \ ___PPC_RA(base) | IMM_L(i)) @@ -63,6 +70,19 @@ ___PPC_RA(base) | IMM_L(i)) #define PPC_LHBRX(r, base, b) EMIT(PPC_INST_LHBRX | ___PPC_RT(r) | \ ___PPC_RA(base) | ___PPC_RB(b)) +#define PPC_LDBRX(r, base, b) EMIT(PPC_INST_LDBRX | ___PPC_RT(r) | \ + ___PPC_RA(base) | ___PPC_RB(b)) + +#define PPC_BPF_LDARX(t, a, b, eh) EMIT(PPC_INST_LDARX | ___PPC_RT(t) | \ + ___PPC_RA(a) | ___PPC_RB(b) | \ + __PPC_EH(eh)) +#define PPC_BPF_LWARX(t, a, b, eh) EMIT(PPC_INST_LWARX | ___PPC_RT(t) | \ + ___PPC_RA(a) | ___PPC_RB(b) | \ + __PPC_EH(eh)) +#define PPC_BPF_STWCX(s, a, b) EMIT(PPC_INST_STWCX | ___PPC_RS(s) | \ + ___PPC_RA(a) | ___PPC_RB(b)) +#define PPC_BPF_STDCX(s, a, b) EMIT(PPC_INST_STDCX | ___PPC_RS(s) | \ + ___PPC_RA(a) | ___PPC_RB(b)) #ifdef CONFIG_PPC64 #define PPC_BPF_LL(r, base, i) do { PPC_LD(r, base, i); } while(0) @@ -76,14 +96,23 @@ #define PPC_CMPWI(a, i) EMIT(PPC_INST_CMPWI | ___PPC_RA(a) | IMM_L(i)) #define PPC_CMPDI(a, i) EMIT(PPC_INST_CMPDI | ___PPC_RA(a) | IMM_L(i)) +#define PPC_CMPW(a, b) EMIT(PPC_INST_CMPW | ___PPC_RA(a) | \ + ___PPC_RB(b)) +#define PPC_CMPD(a, b) EMIT(PPC_INST_CMPD | ___PPC_RA(a) | \ + ___PPC_RB(b)) #define PPC_CMPLWI(a, i) EMIT(PPC_INST_CMPLWI | ___PPC_RA(a) | IMM_L(i)) +#define PPC_CMPLDI(a, i) EMIT(PPC_INST_CMPLDI | ___PPC_RA(a) | IMM_L(i)) #define PPC_CMPLW(a, b) EMIT(PPC_INST_CMPLW | ___PPC_RA(a) | \ ___PPC_RB(b)) +#define PPC_CMPLD(a, b) EMIT(PPC_INST_CMPLD | ___PPC_RA(a) | \ + ___PPC_RB(b)) #define PPC_SUB(d, a, b) EMIT(PPC_INST_SUB | ___PPC_RT(d) | \ ___PPC_RB(a) | ___PPC_RA(b)) #define PPC_ADD(d, a, b) EMIT(PPC_INST_ADD | ___PPC_RT(d) | \ ___PPC_RA(a) | ___PPC_RB(b)) +#define PPC_MULD(d, a, b) EMIT(PPC_INST_MULLD | ___PPC_RT(d) | \ + ___PPC_RA(a) | ___PPC_RB(b)) #define PPC_MULW(d, a, b) EMIT(PPC_INST_MULLW | ___PPC_RT(d) | \ ___PPC_RA(a) | ___PPC_RB(b)) #define PPC_MULHWU(d, a, b) EMIT(PPC_INST_MULHWU | ___PPC_RT(d) | \ @@ -92,6 +121,8 @@ ___PPC_RA(a) | IMM_L(i)) #define PPC_DIVWU(d, a, b) EMIT(PPC_INST_DIVWU | ___PPC_RT(d) | \ ___PPC_RA(a) | ___PPC_RB(b)) +#define PPC_DIVD(d, a, b) EMIT(PPC_INST_DIVD | ___PPC_RT(d) | \ + ___PPC_RA(a) | ___PPC_RB(b)) #define PPC_AND(d, a, b) EMIT(PPC_INST_AND | ___PPC_RA(d) | \ ___PPC_RS(a) | ___PPC_RB(b)) #define PPC_ANDI(d, a, i) EMIT(PPC_INST_ANDI | ___PPC_RA(d) | \ @@ -100,6 +131,7 @@ ___PPC_RS(a) | ___PPC_RB(b)) #define PPC_OR(d, a, b) EMIT(PPC_INST_OR | ___PPC_RA(d) | \ ___PPC_RS(a) | ___PPC_RB(b)) +#define PPC_MR(d, a) PPC_OR(d, a, a) #define PPC_ORI(d, a, i) EMIT(PPC_INST_ORI | ___PPC_RA(d) | \ ___PPC_RS(a) | IMM_L(i)) #define PPC_ORIS(d, a, i) EMIT(PPC_INST_ORIS | ___PPC_RA(d) | \ @@ -110,13 +142,30 @@ ___PPC_RS(a) | IMM_L(i)) #define PPC_XORIS(d, a, i) EMIT(PPC_INST_XORIS | ___PPC_RA(d) | \ ___PPC_RS(a) | IMM_L(i)) +#define PPC_EXTSW(d, a) EMIT(PPC_INST_EXTSW | ___PPC_RA(d) | \ + ___PPC_RS(a)) #define PPC_SLW(d, a, s) EMIT(PPC_INST_SLW | ___PPC_RA(d) | \ ___PPC_RS(a) | ___PPC_RB(s)) +#define PPC_SLD(d, a, s) EMIT(PPC_INST_SLD | ___PPC_RA(d) | \ + ___PPC_RS(a) | ___PPC_RB(s)) #define PPC_SRW(d, a, s) EMIT(PPC_INST_SRW | ___PPC_RA(d) | \ ___PPC_RS(a) | ___PPC_RB(s)) +#define PPC_SRD(d, a, s) EMIT(PPC_INST_SRD | ___PPC_RA(d) | \ + ___PPC_RS(a) | ___PPC_RB(s)) +#define PPC_SRAD(d, a, s) EMIT(PPC_INST_SRAD | ___PPC_RA(d) | \ + ___PPC_RS(a) | ___PPC_RB(s)) +#define PPC_SRADI(d, a, i) EMIT(PPC_INST_SRADI | ___PPC_RA(d) | \ + ___PPC_RS(a) | __PPC_SH(i) | \ + (((i) & 0x20) >> 4)) #define PPC_RLWINM(d, a, i, mb, me) EMIT(PPC_INST_RLWINM | ___PPC_RA(d) | \ ___PPC_RS(a) | __PPC_SH(i) | \ __PPC_MB(mb) | __PPC_ME(me)) +#define PPC_RLWIMI(d, a, i, mb, me) EMIT(PPC_INST_RLWIMI | ___PPC_RA(d) | \ + ___PPC_RS(a) | __PPC_SH(i) | \ + __PPC_MB(mb) | __PPC_ME(me)) +#define PPC_RLDICL(d, a, i, mb) EMIT(PPC_INST_RLDICL | ___PPC_RA(d) | \ + ___PPC_RS(a) | __PPC_SH(i) | \ + __PPC_MB64(mb) | (((i) & 0x20) >> 4)) #define PPC_RLDICR(d, a, i, me) EMIT(PPC_INST_RLDICR | ___PPC_RA(d) | \ ___PPC_RS(a) | __PPC_SH(i) | \ __PPC_ME64(me) | (((i) & 0x20) >> 4)) @@ -127,6 +176,8 @@ #define PPC_SRWI(d, a, i) PPC_RLWINM(d, a, 32-(i), i, 31) /* sldi = rldicr Rx, Ry, n, 63-n */ #define PPC_SLDI(d, a, i) PPC_RLDICR(d, a, i, 63-(i)) +/* sldi = rldicl Rx, Ry, 64-n, n */ +#define PPC_SRDI(d, a, i) PPC_RLDICL(d, a, 64-(i), i) #define PPC_NEG(d, a) EMIT(PPC_INST_NEG | ___PPC_RT(d) | ___PPC_RA(a)) diff --git a/arch/powerpc/net/bpf_jit64.h b/arch/powerpc/net/bpf_jit64.h new file mode 100644 index 000000000000..5046d6f65c02 --- /dev/null +++ b/arch/powerpc/net/bpf_jit64.h @@ -0,0 +1,102 @@ +/* + * bpf_jit64.h: BPF JIT compiler for PPC64 + * + * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> + * IBM Corporation + * + * 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. + */ +#ifndef _BPF_JIT64_H +#define _BPF_JIT64_H + +#include "bpf_jit.h" + +/* + * Stack layout: + * + * [ prev sp ] <------------- + * [ nv gpr save area ] 8*8 | + * fp (r31) --> [ ebpf stack space ] 512 | + * [ local/tmp var space ] 16 | + * [ frame header ] 32/112 | + * sp (r1) ---> [ stack pointer ] -------------- + */ + +/* for bpf JIT code internal usage */ +#define BPF_PPC_STACK_LOCALS 16 +/* for gpr non volatile registers BPG_REG_6 to 10, plus skb cache registers */ +#define BPF_PPC_STACK_SAVE (8*8) +/* Ensure this is quadword aligned */ +#define BPF_PPC_STACKFRAME (STACK_FRAME_MIN_SIZE + BPF_PPC_STACK_LOCALS + \ + MAX_BPF_STACK + BPF_PPC_STACK_SAVE) + +#ifndef __ASSEMBLY__ + +/* BPF register usage */ +#define SKB_HLEN_REG (MAX_BPF_REG + 0) +#define SKB_DATA_REG (MAX_BPF_REG + 1) +#define TMP_REG_1 (MAX_BPF_REG + 2) +#define TMP_REG_2 (MAX_BPF_REG + 3) + +/* BPF to ppc register mappings */ +static const int b2p[] = { + /* function return value */ + [BPF_REG_0] = 8, + /* function arguments */ + [BPF_REG_1] = 3, + [BPF_REG_2] = 4, + [BPF_REG_3] = 5, + [BPF_REG_4] = 6, + [BPF_REG_5] = 7, + /* non volatile registers */ + [BPF_REG_6] = 27, + [BPF_REG_7] = 28, + [BPF_REG_8] = 29, + [BPF_REG_9] = 30, + /* frame pointer aka BPF_REG_10 */ + [BPF_REG_FP] = 31, + /* eBPF jit internal registers */ + [SKB_HLEN_REG] = 25, + [SKB_DATA_REG] = 26, + [TMP_REG_1] = 9, + [TMP_REG_2] = 10 +}; + +/* Assembly helpers */ +#define DECLARE_LOAD_FUNC(func) u64 func(u64 r3, u64 r4); \ + u64 func##_negative_offset(u64 r3, u64 r4); \ + u64 func##_positive_offset(u64 r3, u64 r4); + +DECLARE_LOAD_FUNC(sk_load_word); +DECLARE_LOAD_FUNC(sk_load_half); +DECLARE_LOAD_FUNC(sk_load_byte); + +#define CHOOSE_LOAD_FUNC(imm, func) \ + (imm < 0 ? \ + (imm >= SKF_LL_OFF ? func##_negative_offset : func) : \ + func##_positive_offset) + +#define SEEN_FUNC 0x1000 /* might call external helpers */ +#define SEEN_STACK 0x2000 /* uses BPF stack */ +#define SEEN_SKB 0x4000 /* uses sk_buff */ + +struct codegen_context { + /* + * This is used to track register usage as well + * as calls to external helpers. + * - register usage is tracked with corresponding + * bits (r3-r10 and r25-r31) + * - rest of the bits can be used to track other + * things -- for now, we use bits 16 to 23 + * encoded in SEEN_* macros above + */ + unsigned int seen; + unsigned int idx; +}; + +#endif /* !__ASSEMBLY__ */ + +#endif diff --git a/arch/powerpc/net/bpf_jit_asm64.S b/arch/powerpc/net/bpf_jit_asm64.S new file mode 100644 index 000000000000..7e4c51430b84 --- /dev/null +++ b/arch/powerpc/net/bpf_jit_asm64.S @@ -0,0 +1,180 @@ +/* + * bpf_jit_asm64.S: Packet/header access helper functions + * for PPC64 BPF compiler. + * + * Copyright 2016, Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> + * IBM Corporation + * + * Based on bpf_jit_asm.S by Matt Evans + * + * 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/ppc_asm.h> +#include <asm/ptrace.h> +#include "bpf_jit64.h" + +/* + * All of these routines are called directly from generated code, + * with the below register usage: + * r27 skb pointer (ctx) + * r25 skb header length + * r26 skb->data pointer + * r4 offset + * + * Result is passed back in: + * r8 data read in host endian format (accumulator) + * + * r9 is used as a temporary register + */ + +#define r_skb r27 +#define r_hlen r25 +#define r_data r26 +#define r_off r4 +#define r_val r8 +#define r_tmp r9 + +_GLOBAL_TOC(sk_load_word) + cmpdi r_off, 0 + blt bpf_slow_path_word_neg + b sk_load_word_positive_offset + +_GLOBAL_TOC(sk_load_word_positive_offset) + /* Are we accessing past headlen? */ + subi r_tmp, r_hlen, 4 + cmpd r_tmp, r_off + blt bpf_slow_path_word + /* Nope, just hitting the header. cr0 here is eq or gt! */ + LWZX_BE r_val, r_data, r_off + blr /* Return success, cr0 != LT */ + +_GLOBAL_TOC(sk_load_half) + cmpdi r_off, 0 + blt bpf_slow_path_half_neg + b sk_load_half_positive_offset + +_GLOBAL_TOC(sk_load_half_positive_offset) + subi r_tmp, r_hlen, 2 + cmpd r_tmp, r_off + blt bpf_slow_path_half + LHZX_BE r_val, r_data, r_off + blr + +_GLOBAL_TOC(sk_load_byte) + cmpdi r_off, 0 + blt bpf_slow_path_byte_neg + b sk_load_byte_positive_offset + +_GLOBAL_TOC(sk_load_byte_positive_offset) + cmpd r_hlen, r_off + ble bpf_slow_path_byte + lbzx r_val, r_data, r_off + blr + +/* + * Call out to skb_copy_bits: + * Allocate a new stack frame here to remain ABI-compliant in + * stashing LR. + */ +#define bpf_slow_path_common(SIZE) \ + mflr r0; \ + std r0, PPC_LR_STKOFF(r1); \ + stdu r1, -(STACK_FRAME_MIN_SIZE + BPF_PPC_STACK_LOCALS)(r1); \ + mr r3, r_skb; \ + /* r4 = r_off as passed */ \ + addi r5, r1, STACK_FRAME_MIN_SIZE; \ + li r6, SIZE; \ + bl skb_copy_bits; \ + nop; \ + /* save r5 */ \ + addi r5, r1, STACK_FRAME_MIN_SIZE; \ + /* r3 = 0 on success */ \ + addi r1, r1, STACK_FRAME_MIN_SIZE + BPF_PPC_STACK_LOCALS; \ + ld r0, PPC_LR_STKOFF(r1); \ + mtlr r0; \ + cmpdi r3, 0; \ + blt bpf_error; /* cr0 = LT */ + +bpf_slow_path_word: + bpf_slow_path_common(4) + /* Data value is on stack, and cr0 != LT */ + LWZX_BE r_val, 0, r5 + blr + +bpf_slow_path_half: + bpf_slow_path_common(2) + LHZX_BE r_val, 0, r5 + blr + +bpf_slow_path_byte: + bpf_slow_path_common(1) + lbzx r_val, 0, r5 + blr + +/* + * Call out to bpf_internal_load_pointer_neg_helper + */ +#define sk_negative_common(SIZE) \ + mflr r0; \ + std r0, PPC_LR_STKOFF(r1); \ + stdu r1, -STACK_FRAME_MIN_SIZE(r1); \ + mr r3, r_skb; \ + /* r4 = r_off, as passed */ \ + li r5, SIZE; \ + bl bpf_internal_load_pointer_neg_helper; \ + nop; \ + addi r1, r1, STACK_FRAME_MIN_SIZE; \ + ld r0, PPC_LR_STKOFF(r1); \ + mtlr r0; \ + /* R3 != 0 on success */ \ + cmpldi r3, 0; \ + beq bpf_error_slow; /* cr0 = EQ */ + +bpf_slow_path_word_neg: + lis r_tmp, -32 /* SKF_LL_OFF */ + cmpd r_off, r_tmp /* addr < SKF_* */ + blt bpf_error /* cr0 = LT */ + b sk_load_word_negative_offset + +_GLOBAL_TOC(sk_load_word_negative_offset) + sk_negative_common(4) + LWZX_BE r_val, 0, r3 + blr + +bpf_slow_path_half_neg: + lis r_tmp, -32 /* SKF_LL_OFF */ + cmpd r_off, r_tmp /* addr < SKF_* */ + blt bpf_error /* cr0 = LT */ + b sk_load_half_negative_offset + +_GLOBAL_TOC(sk_load_half_negative_offset) + sk_negative_common(2) + LHZX_BE r_val, 0, r3 + blr + +bpf_slow_path_byte_neg: + lis r_tmp, -32 /* SKF_LL_OFF */ + cmpd r_off, r_tmp /* addr < SKF_* */ + blt bpf_error /* cr0 = LT */ + b sk_load_byte_negative_offset + +_GLOBAL_TOC(sk_load_byte_negative_offset) + sk_negative_common(1) + lbzx r_val, 0, r3 + blr + +bpf_error_slow: + /* fabricate a cr0 = lt */ + li r_tmp, -1 + cmpdi r_tmp, 0 +bpf_error: + /* + * Entered with cr0 = lt + * Generated code will 'blt epilogue', returning 0. + */ + li r_val, 0 + blr diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c new file mode 100644 index 000000000000..6073b78516f6 --- /dev/null +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -0,0 +1,954 @@ +/* + * bpf_jit_comp64.c: eBPF JIT compiler + * + * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> + * IBM Corporation + * + * Based on the powerpc classic BPF JIT compiler by Matt Evans + * + * 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/moduleloader.h> +#include <asm/cacheflush.h> +#include <linux/netdevice.h> +#include <linux/filter.h> +#include <linux/if_vlan.h> +#include <asm/kprobes.h> + +#include "bpf_jit64.h" + +int bpf_jit_enable __read_mostly; + +static void bpf_jit_fill_ill_insns(void *area, unsigned int size) +{ + int *p = area; + + /* Fill whole space with trap instructions */ + while (p < (int *)((char *)area + size)) + *p++ = BREAKPOINT_INSTRUCTION; +} + +static inline void bpf_flush_icache(void *start, void *end) +{ + smp_wmb(); + flush_icache_range((unsigned long)start, (unsigned long)end); +} + +static inline bool bpf_is_seen_register(struct codegen_context *ctx, int i) +{ + return (ctx->seen & (1 << (31 - b2p[i]))); +} + +static inline void bpf_set_seen_register(struct codegen_context *ctx, int i) +{ + ctx->seen |= (1 << (31 - b2p[i])); +} + +static inline bool bpf_has_stack_frame(struct codegen_context *ctx) +{ + /* + * We only need a stack frame if: + * - we call other functions (kernel helpers), or + * - the bpf program uses its stack area + * The latter condition is deduced from the usage of BPF_REG_FP + */ + return ctx->seen & SEEN_FUNC || bpf_is_seen_register(ctx, BPF_REG_FP); +} + +static void bpf_jit_emit_skb_loads(u32 *image, struct codegen_context *ctx) +{ + /* + * Load skb->len and skb->data_len + * r3 points to skb + */ + PPC_LWZ(b2p[SKB_HLEN_REG], 3, offsetof(struct sk_buff, len)); + PPC_LWZ(b2p[TMP_REG_1], 3, offsetof(struct sk_buff, data_len)); + /* header_len = len - data_len */ + PPC_SUB(b2p[SKB_HLEN_REG], b2p[SKB_HLEN_REG], b2p[TMP_REG_1]); + + /* skb->data pointer */ + PPC_BPF_LL(b2p[SKB_DATA_REG], 3, offsetof(struct sk_buff, data)); +} + +static void bpf_jit_emit_func_call(u32 *image, struct codegen_context *ctx, u64 func) +{ +#ifdef PPC64_ELF_ABI_v1 + /* func points to the function descriptor */ + PPC_LI64(b2p[TMP_REG_2], func); + /* Load actual entry point from function descriptor */ + PPC_BPF_LL(b2p[TMP_REG_1], b2p[TMP_REG_2], 0); + /* ... and move it to LR */ + PPC_MTLR(b2p[TMP_REG_1]); + /* + * Load TOC from function descriptor at offset 8. + * We can clobber r2 since we get called through a + * function pointer (so caller will save/restore r2) + * and since we don't use a TOC ourself. + */ + PPC_BPF_LL(2, b2p[TMP_REG_2], 8); +#else + /* We can clobber r12 */ + PPC_FUNC_ADDR(12, func); + PPC_MTLR(12); +#endif + PPC_BLRL(); +} + +static void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx) +{ + int i; + bool new_stack_frame = bpf_has_stack_frame(ctx); + + if (new_stack_frame) { + /* + * We need a stack frame, but we don't necessarily need to + * save/restore LR unless we call other functions + */ + if (ctx->seen & SEEN_FUNC) { + EMIT(PPC_INST_MFLR | __PPC_RT(R0)); + PPC_BPF_STL(0, 1, PPC_LR_STKOFF); + } + + PPC_BPF_STLU(1, 1, -BPF_PPC_STACKFRAME); + } + + /* + * Back up non-volatile regs -- BPF registers 6-10 + * If we haven't created our own stack frame, we save these + * in the protected zone below the previous stack frame + */ + for (i = BPF_REG_6; i <= BPF_REG_10; i++) + if (bpf_is_seen_register(ctx, i)) + PPC_BPF_STL(b2p[i], 1, + (new_stack_frame ? BPF_PPC_STACKFRAME : 0) - + (8 * (32 - b2p[i]))); + + /* + * Save additional non-volatile regs if we cache skb + * Also, setup skb data + */ + if (ctx->seen & SEEN_SKB) { + PPC_BPF_STL(b2p[SKB_HLEN_REG], 1, + BPF_PPC_STACKFRAME - (8 * (32 - b2p[SKB_HLEN_REG]))); + PPC_BPF_STL(b2p[SKB_DATA_REG], 1, + BPF_PPC_STACKFRAME - (8 * (32 - b2p[SKB_DATA_REG]))); + bpf_jit_emit_skb_loads(image, ctx); + } + + /* Setup frame pointer to point to the bpf stack area */ + if (bpf_is_seen_register(ctx, BPF_REG_FP)) + PPC_ADDI(b2p[BPF_REG_FP], 1, + BPF_PPC_STACKFRAME - BPF_PPC_STACK_SAVE); +} + +static void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) +{ + int i; + bool new_stack_frame = bpf_has_stack_frame(ctx); + + /* Move result to r3 */ + PPC_MR(3, b2p[BPF_REG_0]); + + /* Restore NVRs */ + for (i = BPF_REG_6; i <= BPF_REG_10; i++) + if (bpf_is_seen_register(ctx, i)) + PPC_BPF_LL(b2p[i], 1, + (new_stack_frame ? BPF_PPC_STACKFRAME : 0) - + (8 * (32 - b2p[i]))); + + /* Restore non-volatile registers used for skb cache */ + if (ctx->seen & SEEN_SKB) { + PPC_BPF_LL(b2p[SKB_HLEN_REG], 1, + BPF_PPC_STACKFRAME - (8 * (32 - b2p[SKB_HLEN_REG]))); + PPC_BPF_LL(b2p[SKB_DATA_REG], 1, + BPF_PPC_STACKFRAME - (8 * (32 - b2p[SKB_DATA_REG]))); + } + + /* Tear down our stack frame */ + if (new_stack_frame) { + PPC_ADDI(1, 1, BPF_PPC_STACKFRAME); + if (ctx->seen & SEEN_FUNC) { + PPC_BPF_LL(0, 1, PPC_LR_STKOFF); + PPC_MTLR(0); + } + } + + PPC_BLR(); +} + +/* Assemble the body code between the prologue & epilogue */ +static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, + struct codegen_context *ctx, + u32 *addrs) +{ + const struct bpf_insn *insn = fp->insnsi; + int flen = fp->len; + int i; + + /* Start of epilogue code - will only be valid 2nd pass onwards */ + u32 exit_addr = addrs[flen]; + + for (i = 0; i < flen; i++) { + u32 code = insn[i].code; + u32 dst_reg = b2p[insn[i].dst_reg]; + u32 src_reg = b2p[insn[i].src_reg]; + s16 off = insn[i].off; + s32 imm = insn[i].imm; + u64 imm64; + u8 *func; + u32 true_cond; + int stack_local_off; + + /* + * addrs[] maps a BPF bytecode address into a real offset from + * the start of the body code. + */ + addrs[i] = ctx->idx * 4; + + /* + * As an optimization, we note down which non-volatile registers + * are used so that we can only save/restore those in our + * prologue and epilogue. We do this here regardless of whether + * the actual BPF instruction uses src/dst registers or not + * (for instance, BPF_CALL does not use them). The expectation + * is that those instructions will have src_reg/dst_reg set to + * 0. Even otherwise, we just lose some prologue/epilogue + * optimization but everything else should work without + * any issues. + */ + if (dst_reg >= 24 && dst_reg <= 31) + bpf_set_seen_register(ctx, insn[i].dst_reg); + if (src_reg >= 24 && src_reg <= 31) + bpf_set_seen_register(ctx, insn[i].src_reg); + + switch (code) { + /* + * Arithmetic operations: ADD/SUB/MUL/DIV/MOD/NEG + */ + case BPF_ALU | BPF_ADD | BPF_X: /* (u32) dst += (u32) src */ + case BPF_ALU64 | BPF_ADD | BPF_X: /* dst += src */ + PPC_ADD(dst_reg, dst_reg, src_reg); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_SUB | BPF_X: /* (u32) dst -= (u32) src */ + case BPF_ALU64 | BPF_SUB | BPF_X: /* dst -= src */ + PPC_SUB(dst_reg, dst_reg, src_reg); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_ADD | BPF_K: /* (u32) dst += (u32) imm */ + case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */ + case BPF_ALU64 | BPF_ADD | BPF_K: /* dst += imm */ + case BPF_ALU64 | BPF_SUB | BPF_K: /* dst -= imm */ + if (BPF_OP(code) == BPF_SUB) + imm = -imm; + if (imm) { + if (imm >= -32768 && imm < 32768) + PPC_ADDI(dst_reg, dst_reg, IMM_L(imm)); + else { + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_ADD(dst_reg, dst_reg, b2p[TMP_REG_1]); + } + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_MUL | BPF_X: /* (u32) dst *= (u32) src */ + case BPF_ALU64 | BPF_MUL | BPF_X: /* dst *= src */ + if (BPF_CLASS(code) == BPF_ALU) + PPC_MULW(dst_reg, dst_reg, src_reg); + else + PPC_MULD(dst_reg, dst_reg, src_reg); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_MUL | BPF_K: /* (u32) dst *= (u32) imm */ + case BPF_ALU64 | BPF_MUL | BPF_K: /* dst *= imm */ + if (imm >= -32768 && imm < 32768) + PPC_MULI(dst_reg, dst_reg, IMM_L(imm)); + else { + PPC_LI32(b2p[TMP_REG_1], imm); + if (BPF_CLASS(code) == BPF_ALU) + PPC_MULW(dst_reg, dst_reg, + b2p[TMP_REG_1]); + else + PPC_MULD(dst_reg, dst_reg, + b2p[TMP_REG_1]); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_DIV | BPF_X: /* (u32) dst /= (u32) src */ + case BPF_ALU | BPF_MOD | BPF_X: /* (u32) dst %= (u32) src */ + PPC_CMPWI(src_reg, 0); + PPC_BCC_SHORT(COND_NE, (ctx->idx * 4) + 12); + PPC_LI(b2p[BPF_REG_0], 0); + PPC_JMP(exit_addr); + if (BPF_OP(code) == BPF_MOD) { + PPC_DIVWU(b2p[TMP_REG_1], dst_reg, src_reg); + PPC_MULW(b2p[TMP_REG_1], src_reg, + b2p[TMP_REG_1]); + PPC_SUB(dst_reg, dst_reg, b2p[TMP_REG_1]); + } else + PPC_DIVWU(dst_reg, dst_reg, src_reg); + goto bpf_alu32_trunc; + case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */ + case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */ + PPC_CMPDI(src_reg, 0); + PPC_BCC_SHORT(COND_NE, (ctx->idx * 4) + 12); + PPC_LI(b2p[BPF_REG_0], 0); + PPC_JMP(exit_addr); + if (BPF_OP(code) == BPF_MOD) { + PPC_DIVD(b2p[TMP_REG_1], dst_reg, src_reg); + PPC_MULD(b2p[TMP_REG_1], src_reg, + b2p[TMP_REG_1]); + PPC_SUB(dst_reg, dst_reg, b2p[TMP_REG_1]); + } else + PPC_DIVD(dst_reg, dst_reg, src_reg); + break; + case BPF_ALU | BPF_MOD | BPF_K: /* (u32) dst %= (u32) imm */ + case BPF_ALU | BPF_DIV | BPF_K: /* (u32) dst /= (u32) imm */ + case BPF_ALU64 | BPF_MOD | BPF_K: /* dst %= imm */ + case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */ + if (imm == 0) + return -EINVAL; + else if (imm == 1) + goto bpf_alu32_trunc; + + PPC_LI32(b2p[TMP_REG_1], imm); + switch (BPF_CLASS(code)) { + case BPF_ALU: + if (BPF_OP(code) == BPF_MOD) { + PPC_DIVWU(b2p[TMP_REG_2], dst_reg, + b2p[TMP_REG_1]); + PPC_MULW(b2p[TMP_REG_1], + b2p[TMP_REG_1], + b2p[TMP_REG_2]); + PPC_SUB(dst_reg, dst_reg, + b2p[TMP_REG_1]); + } else + PPC_DIVWU(dst_reg, dst_reg, + b2p[TMP_REG_1]); + break; + case BPF_ALU64: + if (BPF_OP(code) == BPF_MOD) { + PPC_DIVD(b2p[TMP_REG_2], dst_reg, + b2p[TMP_REG_1]); + PPC_MULD(b2p[TMP_REG_1], + b2p[TMP_REG_1], + b2p[TMP_REG_2]); + PPC_SUB(dst_reg, dst_reg, + b2p[TMP_REG_1]); + } else + PPC_DIVD(dst_reg, dst_reg, + b2p[TMP_REG_1]); + break; + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_NEG: /* (u32) dst = -dst */ + case BPF_ALU64 | BPF_NEG: /* dst = -dst */ + PPC_NEG(dst_reg, dst_reg); + goto bpf_alu32_trunc; + + /* + * Logical operations: AND/OR/XOR/[A]LSH/[A]RSH + */ + case BPF_ALU | BPF_AND | BPF_X: /* (u32) dst = dst & src */ + case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */ + PPC_AND(dst_reg, dst_reg, src_reg); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_AND | BPF_K: /* (u32) dst = dst & imm */ + case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */ + if (!IMM_H(imm)) + PPC_ANDI(dst_reg, dst_reg, IMM_L(imm)); + else { + /* Sign-extended */ + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_AND(dst_reg, dst_reg, b2p[TMP_REG_1]); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */ + case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */ + PPC_OR(dst_reg, dst_reg, src_reg); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_OR | BPF_K:/* dst = (u32) dst | (u32) imm */ + case BPF_ALU64 | BPF_OR | BPF_K:/* dst = dst | imm */ + if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) { + /* Sign-extended */ + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_OR(dst_reg, dst_reg, b2p[TMP_REG_1]); + } else { + if (IMM_L(imm)) + PPC_ORI(dst_reg, dst_reg, IMM_L(imm)); + if (IMM_H(imm)) + PPC_ORIS(dst_reg, dst_reg, IMM_H(imm)); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_XOR | BPF_X: /* (u32) dst ^= src */ + case BPF_ALU64 | BPF_XOR | BPF_X: /* dst ^= src */ + PPC_XOR(dst_reg, dst_reg, src_reg); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_XOR | BPF_K: /* (u32) dst ^= (u32) imm */ + case BPF_ALU64 | BPF_XOR | BPF_K: /* dst ^= imm */ + if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) { + /* Sign-extended */ + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_XOR(dst_reg, dst_reg, b2p[TMP_REG_1]); + } else { + if (IMM_L(imm)) + PPC_XORI(dst_reg, dst_reg, IMM_L(imm)); + if (IMM_H(imm)) + PPC_XORIS(dst_reg, dst_reg, IMM_H(imm)); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_LSH | BPF_X: /* (u32) dst <<= (u32) src */ + /* slw clears top 32 bits */ + PPC_SLW(dst_reg, dst_reg, src_reg); + break; + case BPF_ALU64 | BPF_LSH | BPF_X: /* dst <<= src; */ + PPC_SLD(dst_reg, dst_reg, src_reg); + break; + case BPF_ALU | BPF_LSH | BPF_K: /* (u32) dst <<== (u32) imm */ + /* with imm 0, we still need to clear top 32 bits */ + PPC_SLWI(dst_reg, dst_reg, imm); + break; + case BPF_ALU64 | BPF_LSH | BPF_K: /* dst <<== imm */ + if (imm != 0) + PPC_SLDI(dst_reg, dst_reg, imm); + break; + case BPF_ALU | BPF_RSH | BPF_X: /* (u32) dst >>= (u32) src */ + PPC_SRW(dst_reg, dst_reg, src_reg); + break; + case BPF_ALU64 | BPF_RSH | BPF_X: /* dst >>= src */ + PPC_SRD(dst_reg, dst_reg, src_reg); + break; + case BPF_ALU | BPF_RSH | BPF_K: /* (u32) dst >>= (u32) imm */ + PPC_SRWI(dst_reg, dst_reg, imm); + break; + case BPF_ALU64 | BPF_RSH | BPF_K: /* dst >>= imm */ + if (imm != 0) + PPC_SRDI(dst_reg, dst_reg, imm); + break; + case BPF_ALU64 | BPF_ARSH | BPF_X: /* (s64) dst >>= src */ + PPC_SRAD(dst_reg, dst_reg, src_reg); + break; + case BPF_ALU64 | BPF_ARSH | BPF_K: /* (s64) dst >>= imm */ + if (imm != 0) + PPC_SRADI(dst_reg, dst_reg, imm); + break; + + /* + * MOV + */ + case BPF_ALU | BPF_MOV | BPF_X: /* (u32) dst = src */ + case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */ + PPC_MR(dst_reg, src_reg); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_MOV | BPF_K: /* (u32) dst = imm */ + case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = (s64) imm */ + PPC_LI32(dst_reg, imm); + if (imm < 0) + goto bpf_alu32_trunc; + break; + +bpf_alu32_trunc: + /* Truncate to 32-bits */ + if (BPF_CLASS(code) == BPF_ALU) + PPC_RLWINM(dst_reg, dst_reg, 0, 0, 31); + break; + + /* + * BPF_FROM_BE/LE + */ + case BPF_ALU | BPF_END | BPF_FROM_LE: + case BPF_ALU | BPF_END | BPF_FROM_BE: +#ifdef __BIG_ENDIAN__ + if (BPF_SRC(code) == BPF_FROM_BE) + goto emit_clear; +#else /* !__BIG_ENDIAN__ */ + if (BPF_SRC(code) == BPF_FROM_LE) + goto emit_clear; +#endif + switch (imm) { + case 16: + /* Rotate 8 bits left & mask with 0x0000ff00 */ + PPC_RLWINM(b2p[TMP_REG_1], dst_reg, 8, 16, 23); + /* Rotate 8 bits right & insert LSB to reg */ + PPC_RLWIMI(b2p[TMP_REG_1], dst_reg, 24, 24, 31); + /* Move result back to dst_reg */ + PPC_MR(dst_reg, b2p[TMP_REG_1]); + break; + case 32: + /* + * Rotate word left by 8 bits: + * 2 bytes are already in their final position + * -- byte 2 and 4 (of bytes 1, 2, 3 and 4) + */ + PPC_RLWINM(b2p[TMP_REG_1], dst_reg, 8, 0, 31); + /* Rotate 24 bits and insert byte 1 */ + PPC_RLWIMI(b2p[TMP_REG_1], dst_reg, 24, 0, 7); + /* Rotate 24 bits and insert byte 3 */ + PPC_RLWIMI(b2p[TMP_REG_1], dst_reg, 24, 16, 23); + PPC_MR(dst_reg, b2p[TMP_REG_1]); + break; + case 64: + /* + * Way easier and faster(?) to store the value + * into stack and then use ldbrx + * + * First, determine where in stack we can store + * this: + * - if we have allotted a stack frame, then we + * will utilize the area set aside by + * BPF_PPC_STACK_LOCALS + * - else, we use the area beneath the NV GPR + * save area + * + * ctx->seen will be reliable in pass2, but + * the instructions generated will remain the + * same across all passes + */ + if (bpf_has_stack_frame(ctx)) + stack_local_off = STACK_FRAME_MIN_SIZE; + else + stack_local_off = -(BPF_PPC_STACK_SAVE + 8); + + PPC_STD(dst_reg, 1, stack_local_off); + PPC_ADDI(b2p[TMP_REG_1], 1, stack_local_off); + PPC_LDBRX(dst_reg, 0, b2p[TMP_REG_1]); + break; + } + break; + +emit_clear: + switch (imm) { + case 16: + /* zero-extend 16 bits into 64 bits */ + PPC_RLDICL(dst_reg, dst_reg, 0, 48); + break; + case 32: + /* zero-extend 32 bits into 64 bits */ + PPC_RLDICL(dst_reg, dst_reg, 0, 32); + break; + case 64: + /* nop */ + break; + } + break; + + /* + * BPF_ST(X) + */ + case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src */ + case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */ + if (BPF_CLASS(code) == BPF_ST) { + PPC_LI(b2p[TMP_REG_1], imm); + src_reg = b2p[TMP_REG_1]; + } + PPC_STB(src_reg, dst_reg, off); + break; + case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */ + case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */ + if (BPF_CLASS(code) == BPF_ST) { + PPC_LI(b2p[TMP_REG_1], imm); + src_reg = b2p[TMP_REG_1]; + } + PPC_STH(src_reg, dst_reg, off); + break; + case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */ + case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */ + if (BPF_CLASS(code) == BPF_ST) { + PPC_LI32(b2p[TMP_REG_1], imm); + src_reg = b2p[TMP_REG_1]; + } + PPC_STW(src_reg, dst_reg, off); + break; + case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */ + case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */ + if (BPF_CLASS(code) == BPF_ST) { + PPC_LI32(b2p[TMP_REG_1], imm); + src_reg = b2p[TMP_REG_1]; + } + PPC_STD(src_reg, dst_reg, off); + break; + + /* + * BPF_STX XADD (atomic_add) + */ + /* *(u32 *)(dst + off) += src */ + case BPF_STX | BPF_XADD | BPF_W: + /* Get EA into TMP_REG_1 */ + PPC_ADDI(b2p[TMP_REG_1], dst_reg, off); + /* error if EA is not word-aligned */ + PPC_ANDI(b2p[TMP_REG_2], b2p[TMP_REG_1], 0x03); + PPC_BCC_SHORT(COND_EQ, (ctx->idx * 4) + 12); + PPC_LI(b2p[BPF_REG_0], 0); + PPC_JMP(exit_addr); + /* load value from memory into TMP_REG_2 */ + PPC_BPF_LWARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0); + /* add value from src_reg into this */ + PPC_ADD(b2p[TMP_REG_2], b2p[TMP_REG_2], src_reg); + /* store result back */ + PPC_BPF_STWCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]); + /* we're done if this succeeded */ + PPC_BCC_SHORT(COND_EQ, (ctx->idx * 4) + (7*4)); + /* otherwise, let's try once more */ + PPC_BPF_LWARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0); + PPC_ADD(b2p[TMP_REG_2], b2p[TMP_REG_2], src_reg); + PPC_BPF_STWCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]); + /* exit if the store was not successful */ + PPC_LI(b2p[BPF_REG_0], 0); + PPC_BCC(COND_NE, exit_addr); + break; + /* *(u64 *)(dst + off) += src */ + case BPF_STX | BPF_XADD | BPF_DW: + PPC_ADDI(b2p[TMP_REG_1], dst_reg, off); + /* error if EA is not doubleword-aligned */ + PPC_ANDI(b2p[TMP_REG_2], b2p[TMP_REG_1], 0x07); + PPC_BCC_SHORT(COND_EQ, (ctx->idx * 4) + (3*4)); + PPC_LI(b2p[BPF_REG_0], 0); + PPC_JMP(exit_addr); + PPC_BPF_LDARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0); + PPC_ADD(b2p[TMP_REG_2], b2p[TMP_REG_2], src_reg); + PPC_BPF_STDCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]); + PPC_BCC_SHORT(COND_EQ, (ctx->idx * 4) + (7*4)); + PPC_BPF_LDARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0); + PPC_ADD(b2p[TMP_REG_2], b2p[TMP_REG_2], src_reg); + PPC_BPF_STDCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]); + PPC_LI(b2p[BPF_REG_0], 0); + PPC_BCC(COND_NE, exit_addr); + break; + + /* + * BPF_LDX + */ + /* dst = *(u8 *)(ul) (src + off) */ + case BPF_LDX | BPF_MEM | BPF_B: + PPC_LBZ(dst_reg, src_reg, off); + break; + /* dst = *(u16 *)(ul) (src + off) */ + case BPF_LDX | BPF_MEM | BPF_H: + PPC_LHZ(dst_reg, src_reg, off); + break; + /* dst = *(u32 *)(ul) (src + off) */ + case BPF_LDX | BPF_MEM | BPF_W: + PPC_LWZ(dst_reg, src_reg, off); + break; + /* dst = *(u64 *)(ul) (src + off) */ + case BPF_LDX | BPF_MEM | BPF_DW: + PPC_LD(dst_reg, src_reg, off); + break; + + /* + * Doubleword load + * 16 byte instruction that uses two 'struct bpf_insn' + */ + case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */ + imm64 = ((u64)(u32) insn[i].imm) | + (((u64)(u32) insn[i+1].imm) << 32); + /* Adjust for two bpf instructions */ + addrs[++i] = ctx->idx * 4; + PPC_LI64(dst_reg, imm64); + break; + + /* + * Return/Exit + */ + case BPF_JMP | BPF_EXIT: + /* + * If this isn't the very last instruction, branch to + * the epilogue. If we _are_ the last instruction, + * we'll just fall through to the epilogue. + */ + if (i != flen - 1) + PPC_JMP(exit_addr); + /* else fall through to the epilogue */ + break; + + /* + * Call kernel helper + */ + case BPF_JMP | BPF_CALL: + ctx->seen |= SEEN_FUNC; + func = (u8 *) __bpf_call_base + imm; + + /* Save skb pointer if we need to re-cache skb data */ + if (bpf_helper_changes_skb_data(func)) + PPC_BPF_STL(3, 1, STACK_FRAME_MIN_SIZE); + + bpf_jit_emit_func_call(image, ctx, (u64)func); + + /* move return value from r3 to BPF_REG_0 */ + PPC_MR(b2p[BPF_REG_0], 3); + + /* refresh skb cache */ + if (bpf_helper_changes_skb_data(func)) { + /* reload skb pointer to r3 */ + PPC_BPF_LL(3, 1, STACK_FRAME_MIN_SIZE); + bpf_jit_emit_skb_loads(image, ctx); + } + break; + + /* + * Jumps and branches + */ + case BPF_JMP | BPF_JA: + PPC_JMP(addrs[i + 1 + off]); + break; + + case BPF_JMP | BPF_JGT | BPF_K: + case BPF_JMP | BPF_JGT | BPF_X: + case BPF_JMP | BPF_JSGT | BPF_K: + case BPF_JMP | BPF_JSGT | BPF_X: + true_cond = COND_GT; + goto cond_branch; + case BPF_JMP | BPF_JGE | BPF_K: + case BPF_JMP | BPF_JGE | BPF_X: + case BPF_JMP | BPF_JSGE | BPF_K: + case BPF_JMP | BPF_JSGE | BPF_X: + true_cond = COND_GE; + goto cond_branch; + case BPF_JMP | BPF_JEQ | BPF_K: + case BPF_JMP | BPF_JEQ | BPF_X: + true_cond = COND_EQ; + goto cond_branch; + case BPF_JMP | BPF_JNE | BPF_K: + case BPF_JMP | BPF_JNE | BPF_X: + true_cond = COND_NE; + goto cond_branch; + case BPF_JMP | BPF_JSET | BPF_K: + case BPF_JMP | BPF_JSET | BPF_X: + true_cond = COND_NE; + /* Fall through */ + +cond_branch: + switch (code) { + case BPF_JMP | BPF_JGT | BPF_X: + case BPF_JMP | BPF_JGE | BPF_X: + case BPF_JMP | BPF_JEQ | BPF_X: + case BPF_JMP | BPF_JNE | BPF_X: + /* unsigned comparison */ + PPC_CMPLD(dst_reg, src_reg); + break; + case BPF_JMP | BPF_JSGT | BPF_X: + case BPF_JMP | BPF_JSGE | BPF_X: + /* signed comparison */ + PPC_CMPD(dst_reg, src_reg); + break; + case BPF_JMP | BPF_JSET | BPF_X: + PPC_AND_DOT(b2p[TMP_REG_1], dst_reg, src_reg); + break; + case BPF_JMP | BPF_JNE | BPF_K: + case BPF_JMP | BPF_JEQ | BPF_K: + case BPF_JMP | BPF_JGT | BPF_K: + case BPF_JMP | BPF_JGE | BPF_K: + /* + * Need sign-extended load, so only positive + * values can be used as imm in cmpldi + */ + if (imm >= 0 && imm < 32768) + PPC_CMPLDI(dst_reg, imm); + else { + /* sign-extending load */ + PPC_LI32(b2p[TMP_REG_1], imm); + /* ... but unsigned comparison */ + PPC_CMPLD(dst_reg, b2p[TMP_REG_1]); + } + break; + case BPF_JMP | BPF_JSGT | BPF_K: + case BPF_JMP | BPF_JSGE | BPF_K: + /* + * signed comparison, so any 16-bit value + * can be used in cmpdi + */ + if (imm >= -32768 && imm < 32768) + PPC_CMPDI(dst_reg, imm); + else { + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_CMPD(dst_reg, b2p[TMP_REG_1]); + } + break; + case BPF_JMP | BPF_JSET | BPF_K: + /* andi does not sign-extend the immediate */ + if (imm >= 0 && imm < 32768) + /* PPC_ANDI is _only/always_ dot-form */ + PPC_ANDI(b2p[TMP_REG_1], dst_reg, imm); + else { + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_AND_DOT(b2p[TMP_REG_1], dst_reg, + b2p[TMP_REG_1]); + } + break; + } + PPC_BCC(true_cond, addrs[i + 1 + off]); + break; + + /* + * Loads from packet header/data + * Assume 32-bit input value in imm and X (src_reg) + */ + + /* Absolute loads */ + case BPF_LD | BPF_W | BPF_ABS: + func = (u8 *)CHOOSE_LOAD_FUNC(imm, sk_load_word); + goto common_load_abs; + case BPF_LD | BPF_H | BPF_ABS: + func = (u8 *)CHOOSE_LOAD_FUNC(imm, sk_load_half); + goto common_load_abs; + case BPF_LD | BPF_B | BPF_ABS: + func = (u8 *)CHOOSE_LOAD_FUNC(imm, sk_load_byte); +common_load_abs: + /* + * Load from [imm] + * Load into r4, which can just be passed onto + * skb load helpers as the second parameter + */ + PPC_LI32(4, imm); + goto common_load; + + /* Indirect loads */ + case BPF_LD | BPF_W | BPF_IND: + func = (u8 *)sk_load_word; + goto common_load_ind; + case BPF_LD | BPF_H | BPF_IND: + func = (u8 *)sk_load_half; + goto common_load_ind; + case BPF_LD | BPF_B | BPF_IND: + func = (u8 *)sk_load_byte; +common_load_ind: + /* + * Load from [src_reg + imm] + * Treat src_reg as a 32-bit value + */ + PPC_EXTSW(4, src_reg); + if (imm) { + if (imm >= -32768 && imm < 32768) + PPC_ADDI(4, 4, IMM_L(imm)); + else { + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_ADD(4, 4, b2p[TMP_REG_1]); + } + } + +common_load: + ctx->seen |= SEEN_SKB; + ctx->seen |= SEEN_FUNC; + bpf_jit_emit_func_call(image, ctx, (u64)func); + + /* + * Helper returns 'lt' condition on error, and an + * appropriate return value in BPF_REG_0 + */ + PPC_BCC(COND_LT, exit_addr); + break; + + /* + * TODO: Tail call + */ + case BPF_JMP | BPF_CALL | BPF_X: + + default: + /* + * The filter contains something cruel & unusual. + * We don't handle it, but also there shouldn't be + * anything missing from our list. + */ + pr_err_ratelimited("eBPF filter opcode %04x (@%d) unsupported\n", + code, i); + return -ENOTSUPP; + } + } + + /* Set end-of-body-code address for exit. */ + addrs[i] = ctx->idx * 4; + + return 0; +} + +void bpf_jit_compile(struct bpf_prog *fp) { } + +struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) +{ + u32 proglen; + u32 alloclen; + u8 *image = NULL; + u32 *code_base; + u32 *addrs; + struct codegen_context cgctx; + int pass; + int flen; + struct bpf_binary_header *bpf_hdr; + + if (!bpf_jit_enable) + return fp; + + flen = fp->len; + addrs = kzalloc((flen+1) * sizeof(*addrs), GFP_KERNEL); + if (addrs == NULL) + return fp; + + cgctx.idx = 0; + cgctx.seen = 0; + /* Scouting faux-generate pass 0 */ + if (bpf_jit_build_body(fp, 0, &cgctx, addrs)) + /* We hit something illegal or unsupported. */ + goto out; + + /* + * Pretend to build prologue, given the features we've seen. This will + * update ctgtx.idx as it pretends to output instructions, then we can + * calculate total size from idx. + */ + bpf_jit_build_prologue(0, &cgctx); + bpf_jit_build_epilogue(0, &cgctx); + + proglen = cgctx.idx * 4; + alloclen = proglen + FUNCTION_DESCR_SIZE; + + bpf_hdr = bpf_jit_binary_alloc(alloclen, &image, 4, + bpf_jit_fill_ill_insns); + if (!bpf_hdr) + goto out; + + code_base = (u32 *)(image + FUNCTION_DESCR_SIZE); + + /* Code generation passes 1-2 */ + for (pass = 1; pass < 3; pass++) { + /* Now build the prologue, body code & epilogue for real. */ + cgctx.idx = 0; + bpf_jit_build_prologue(code_base, &cgctx); + bpf_jit_build_body(fp, code_base, &cgctx, addrs); + bpf_jit_build_epilogue(code_base, &cgctx); + + if (bpf_jit_enable > 1) + pr_info("Pass %d: shrink = %d, seen = 0x%x\n", pass, + proglen - (cgctx.idx * 4), cgctx.seen); + } + + if (bpf_jit_enable > 1) + /* + * Note that we output the base address of the code_base + * rather than image, since opcodes are in code_base. + */ + bpf_jit_dump(flen, proglen, pass, code_base); + + if (image) { + bpf_flush_icache(bpf_hdr, image + alloclen); +#ifdef PPC64_ELF_ABI_v1 + /* Function descriptor nastiness: Address + TOC */ + ((u64 *)image)[0] = (u64)code_base; + ((u64 *)image)[1] = local_paca->kernel_toc; +#endif + fp->bpf_func = (void *)image; + fp->jited = 1; + } + +out: + kfree(addrs); + return fp; +} + +void bpf_jit_free(struct bpf_prog *fp) +{ + unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK; + struct bpf_binary_header *bpf_hdr = (void *)addr; + + if (fp->jited) + bpf_jit_binary_free(bpf_hdr); + + bpf_prog_unlock_free(fp); +} |