mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-23 09:09:36 +07:00
6396bb2215
The kzalloc() function has a 2-factor argument form, kcalloc(). This patch replaces cases of: kzalloc(a * b, gfp) with: kcalloc(a * b, gfp) as well as handling cases of: kzalloc(a * b * c, gfp) with: kzalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kzalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kzalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kzalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kzalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kzalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(char) * COUNT + COUNT , ...) | kzalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kzalloc + kcalloc ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kzalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kzalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kzalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kzalloc(C1 * C2 * C3, ...) | kzalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kzalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kzalloc(sizeof(THING) * C2, ...) | kzalloc(sizeof(TYPE) * C2, ...) | kzalloc(C1 * C2 * C3, ...) | kzalloc(C1 * C2, ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - (E1) * E2 + E1, E2 , ...) | - kzalloc + kcalloc ( - (E1) * (E2) + E1, E2 , ...) | - kzalloc + kcalloc ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
689 lines
19 KiB
C
689 lines
19 KiB
C
/* bpf_jit_comp.c: BPF JIT compiler
|
|
*
|
|
* Copyright 2011 Matt Evans <matt@ozlabs.org>, IBM Corporation
|
|
*
|
|
* Based on the x86 BPF compiler, by Eric Dumazet (eric.dumazet@gmail.com)
|
|
* Ported to ppc32 by Denis Kirjanov <kda@linux-powerpc.org>
|
|
*
|
|
* 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 "bpf_jit32.h"
|
|
|
|
static inline void bpf_flush_icache(void *start, void *end)
|
|
{
|
|
smp_wmb();
|
|
flush_icache_range((unsigned long)start, (unsigned long)end);
|
|
}
|
|
|
|
static void bpf_jit_build_prologue(struct bpf_prog *fp, u32 *image,
|
|
struct codegen_context *ctx)
|
|
{
|
|
int i;
|
|
const struct sock_filter *filter = fp->insns;
|
|
|
|
if (ctx->seen & (SEEN_MEM | SEEN_DATAREF)) {
|
|
/* Make stackframe */
|
|
if (ctx->seen & SEEN_DATAREF) {
|
|
/* If we call any helpers (for loads), save LR */
|
|
EMIT(PPC_INST_MFLR | __PPC_RT(R0));
|
|
PPC_BPF_STL(0, 1, PPC_LR_STKOFF);
|
|
|
|
/* Back up non-volatile regs. */
|
|
PPC_BPF_STL(r_D, 1, -(REG_SZ*(32-r_D)));
|
|
PPC_BPF_STL(r_HL, 1, -(REG_SZ*(32-r_HL)));
|
|
}
|
|
if (ctx->seen & SEEN_MEM) {
|
|
/*
|
|
* Conditionally save regs r15-r31 as some will be used
|
|
* for M[] data.
|
|
*/
|
|
for (i = r_M; i < (r_M+16); i++) {
|
|
if (ctx->seen & (1 << (i-r_M)))
|
|
PPC_BPF_STL(i, 1, -(REG_SZ*(32-i)));
|
|
}
|
|
}
|
|
PPC_BPF_STLU(1, 1, -BPF_PPC_STACKFRAME);
|
|
}
|
|
|
|
if (ctx->seen & SEEN_DATAREF) {
|
|
/*
|
|
* If this filter needs to access skb data,
|
|
* prepare r_D and r_HL:
|
|
* r_HL = skb->len - skb->data_len
|
|
* r_D = skb->data
|
|
*/
|
|
PPC_LWZ_OFFS(r_scratch1, r_skb, offsetof(struct sk_buff,
|
|
data_len));
|
|
PPC_LWZ_OFFS(r_HL, r_skb, offsetof(struct sk_buff, len));
|
|
PPC_SUB(r_HL, r_HL, r_scratch1);
|
|
PPC_LL_OFFS(r_D, r_skb, offsetof(struct sk_buff, data));
|
|
}
|
|
|
|
if (ctx->seen & SEEN_XREG) {
|
|
/*
|
|
* TODO: Could also detect whether first instr. sets X and
|
|
* avoid this (as below, with A).
|
|
*/
|
|
PPC_LI(r_X, 0);
|
|
}
|
|
|
|
/* make sure we dont leak kernel information to user */
|
|
if (bpf_needs_clear_a(&filter[0]))
|
|
PPC_LI(r_A, 0);
|
|
}
|
|
|
|
static void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx)
|
|
{
|
|
int i;
|
|
|
|
if (ctx->seen & (SEEN_MEM | SEEN_DATAREF)) {
|
|
PPC_ADDI(1, 1, BPF_PPC_STACKFRAME);
|
|
if (ctx->seen & SEEN_DATAREF) {
|
|
PPC_BPF_LL(0, 1, PPC_LR_STKOFF);
|
|
PPC_MTLR(0);
|
|
PPC_BPF_LL(r_D, 1, -(REG_SZ*(32-r_D)));
|
|
PPC_BPF_LL(r_HL, 1, -(REG_SZ*(32-r_HL)));
|
|
}
|
|
if (ctx->seen & SEEN_MEM) {
|
|
/* Restore any saved non-vol registers */
|
|
for (i = r_M; i < (r_M+16); i++) {
|
|
if (ctx->seen & (1 << (i-r_M)))
|
|
PPC_BPF_LL(i, 1, -(REG_SZ*(32-i)));
|
|
}
|
|
}
|
|
}
|
|
/* The RETs have left a return value in R3. */
|
|
|
|
PPC_BLR();
|
|
}
|
|
|
|
#define CHOOSE_LOAD_FUNC(K, func) \
|
|
((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset)
|
|
|
|
/* Assemble the body code between the prologue & epilogue. */
|
|
static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
|
|
struct codegen_context *ctx,
|
|
unsigned int *addrs)
|
|
{
|
|
const struct sock_filter *filter = fp->insns;
|
|
int flen = fp->len;
|
|
u8 *func;
|
|
unsigned int true_cond;
|
|
int i;
|
|
|
|
/* Start of epilogue code */
|
|
unsigned int exit_addr = addrs[flen];
|
|
|
|
for (i = 0; i < flen; i++) {
|
|
unsigned int K = filter[i].k;
|
|
u16 code = bpf_anc_helper(&filter[i]);
|
|
|
|
/*
|
|
* addrs[] maps a BPF bytecode address into a real offset from
|
|
* the start of the body code.
|
|
*/
|
|
addrs[i] = ctx->idx * 4;
|
|
|
|
switch (code) {
|
|
/*** ALU ops ***/
|
|
case BPF_ALU | BPF_ADD | BPF_X: /* A += X; */
|
|
ctx->seen |= SEEN_XREG;
|
|
PPC_ADD(r_A, r_A, r_X);
|
|
break;
|
|
case BPF_ALU | BPF_ADD | BPF_K: /* A += K; */
|
|
if (!K)
|
|
break;
|
|
PPC_ADDI(r_A, r_A, IMM_L(K));
|
|
if (K >= 32768)
|
|
PPC_ADDIS(r_A, r_A, IMM_HA(K));
|
|
break;
|
|
case BPF_ALU | BPF_SUB | BPF_X: /* A -= X; */
|
|
ctx->seen |= SEEN_XREG;
|
|
PPC_SUB(r_A, r_A, r_X);
|
|
break;
|
|
case BPF_ALU | BPF_SUB | BPF_K: /* A -= K */
|
|
if (!K)
|
|
break;
|
|
PPC_ADDI(r_A, r_A, IMM_L(-K));
|
|
if (K >= 32768)
|
|
PPC_ADDIS(r_A, r_A, IMM_HA(-K));
|
|
break;
|
|
case BPF_ALU | BPF_MUL | BPF_X: /* A *= X; */
|
|
ctx->seen |= SEEN_XREG;
|
|
PPC_MULW(r_A, r_A, r_X);
|
|
break;
|
|
case BPF_ALU | BPF_MUL | BPF_K: /* A *= K */
|
|
if (K < 32768)
|
|
PPC_MULI(r_A, r_A, K);
|
|
else {
|
|
PPC_LI32(r_scratch1, K);
|
|
PPC_MULW(r_A, r_A, r_scratch1);
|
|
}
|
|
break;
|
|
case BPF_ALU | BPF_MOD | BPF_X: /* A %= X; */
|
|
case BPF_ALU | BPF_DIV | BPF_X: /* A /= X; */
|
|
ctx->seen |= SEEN_XREG;
|
|
PPC_CMPWI(r_X, 0);
|
|
if (ctx->pc_ret0 != -1) {
|
|
PPC_BCC(COND_EQ, addrs[ctx->pc_ret0]);
|
|
} else {
|
|
PPC_BCC_SHORT(COND_NE, (ctx->idx*4)+12);
|
|
PPC_LI(r_ret, 0);
|
|
PPC_JMP(exit_addr);
|
|
}
|
|
if (code == (BPF_ALU | BPF_MOD | BPF_X)) {
|
|
PPC_DIVWU(r_scratch1, r_A, r_X);
|
|
PPC_MULW(r_scratch1, r_X, r_scratch1);
|
|
PPC_SUB(r_A, r_A, r_scratch1);
|
|
} else {
|
|
PPC_DIVWU(r_A, r_A, r_X);
|
|
}
|
|
break;
|
|
case BPF_ALU | BPF_MOD | BPF_K: /* A %= K; */
|
|
PPC_LI32(r_scratch2, K);
|
|
PPC_DIVWU(r_scratch1, r_A, r_scratch2);
|
|
PPC_MULW(r_scratch1, r_scratch2, r_scratch1);
|
|
PPC_SUB(r_A, r_A, r_scratch1);
|
|
break;
|
|
case BPF_ALU | BPF_DIV | BPF_K: /* A /= K */
|
|
if (K == 1)
|
|
break;
|
|
PPC_LI32(r_scratch1, K);
|
|
PPC_DIVWU(r_A, r_A, r_scratch1);
|
|
break;
|
|
case BPF_ALU | BPF_AND | BPF_X:
|
|
ctx->seen |= SEEN_XREG;
|
|
PPC_AND(r_A, r_A, r_X);
|
|
break;
|
|
case BPF_ALU | BPF_AND | BPF_K:
|
|
if (!IMM_H(K))
|
|
PPC_ANDI(r_A, r_A, K);
|
|
else {
|
|
PPC_LI32(r_scratch1, K);
|
|
PPC_AND(r_A, r_A, r_scratch1);
|
|
}
|
|
break;
|
|
case BPF_ALU | BPF_OR | BPF_X:
|
|
ctx->seen |= SEEN_XREG;
|
|
PPC_OR(r_A, r_A, r_X);
|
|
break;
|
|
case BPF_ALU | BPF_OR | BPF_K:
|
|
if (IMM_L(K))
|
|
PPC_ORI(r_A, r_A, IMM_L(K));
|
|
if (K >= 65536)
|
|
PPC_ORIS(r_A, r_A, IMM_H(K));
|
|
break;
|
|
case BPF_ANC | SKF_AD_ALU_XOR_X:
|
|
case BPF_ALU | BPF_XOR | BPF_X: /* A ^= X */
|
|
ctx->seen |= SEEN_XREG;
|
|
PPC_XOR(r_A, r_A, r_X);
|
|
break;
|
|
case BPF_ALU | BPF_XOR | BPF_K: /* A ^= K */
|
|
if (IMM_L(K))
|
|
PPC_XORI(r_A, r_A, IMM_L(K));
|
|
if (K >= 65536)
|
|
PPC_XORIS(r_A, r_A, IMM_H(K));
|
|
break;
|
|
case BPF_ALU | BPF_LSH | BPF_X: /* A <<= X; */
|
|
ctx->seen |= SEEN_XREG;
|
|
PPC_SLW(r_A, r_A, r_X);
|
|
break;
|
|
case BPF_ALU | BPF_LSH | BPF_K:
|
|
if (K == 0)
|
|
break;
|
|
else
|
|
PPC_SLWI(r_A, r_A, K);
|
|
break;
|
|
case BPF_ALU | BPF_RSH | BPF_X: /* A >>= X; */
|
|
ctx->seen |= SEEN_XREG;
|
|
PPC_SRW(r_A, r_A, r_X);
|
|
break;
|
|
case BPF_ALU | BPF_RSH | BPF_K: /* A >>= K; */
|
|
if (K == 0)
|
|
break;
|
|
else
|
|
PPC_SRWI(r_A, r_A, K);
|
|
break;
|
|
case BPF_ALU | BPF_NEG:
|
|
PPC_NEG(r_A, r_A);
|
|
break;
|
|
case BPF_RET | BPF_K:
|
|
PPC_LI32(r_ret, K);
|
|
if (!K) {
|
|
if (ctx->pc_ret0 == -1)
|
|
ctx->pc_ret0 = i;
|
|
}
|
|
/*
|
|
* If this isn't the very last instruction, branch to
|
|
* the epilogue if we've stuff to clean up. Otherwise,
|
|
* if there's nothing to tidy, just return. If we /are/
|
|
* the last instruction, we're about to fall through to
|
|
* the epilogue to return.
|
|
*/
|
|
if (i != flen - 1) {
|
|
/*
|
|
* Note: 'seen' is properly valid only on pass
|
|
* #2. Both parts of this conditional are the
|
|
* same instruction size though, meaning the
|
|
* first pass will still correctly determine the
|
|
* code size/addresses.
|
|
*/
|
|
if (ctx->seen)
|
|
PPC_JMP(exit_addr);
|
|
else
|
|
PPC_BLR();
|
|
}
|
|
break;
|
|
case BPF_RET | BPF_A:
|
|
PPC_MR(r_ret, r_A);
|
|
if (i != flen - 1) {
|
|
if (ctx->seen)
|
|
PPC_JMP(exit_addr);
|
|
else
|
|
PPC_BLR();
|
|
}
|
|
break;
|
|
case BPF_MISC | BPF_TAX: /* X = A */
|
|
PPC_MR(r_X, r_A);
|
|
break;
|
|
case BPF_MISC | BPF_TXA: /* A = X */
|
|
ctx->seen |= SEEN_XREG;
|
|
PPC_MR(r_A, r_X);
|
|
break;
|
|
|
|
/*** Constant loads/M[] access ***/
|
|
case BPF_LD | BPF_IMM: /* A = K */
|
|
PPC_LI32(r_A, K);
|
|
break;
|
|
case BPF_LDX | BPF_IMM: /* X = K */
|
|
PPC_LI32(r_X, K);
|
|
break;
|
|
case BPF_LD | BPF_MEM: /* A = mem[K] */
|
|
PPC_MR(r_A, r_M + (K & 0xf));
|
|
ctx->seen |= SEEN_MEM | (1<<(K & 0xf));
|
|
break;
|
|
case BPF_LDX | BPF_MEM: /* X = mem[K] */
|
|
PPC_MR(r_X, r_M + (K & 0xf));
|
|
ctx->seen |= SEEN_MEM | (1<<(K & 0xf));
|
|
break;
|
|
case BPF_ST: /* mem[K] = A */
|
|
PPC_MR(r_M + (K & 0xf), r_A);
|
|
ctx->seen |= SEEN_MEM | (1<<(K & 0xf));
|
|
break;
|
|
case BPF_STX: /* mem[K] = X */
|
|
PPC_MR(r_M + (K & 0xf), r_X);
|
|
ctx->seen |= SEEN_XREG | SEEN_MEM | (1<<(K & 0xf));
|
|
break;
|
|
case BPF_LD | BPF_W | BPF_LEN: /* A = skb->len; */
|
|
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4);
|
|
PPC_LWZ_OFFS(r_A, r_skb, offsetof(struct sk_buff, len));
|
|
break;
|
|
case BPF_LDX | BPF_W | BPF_ABS: /* A = *((u32 *)(seccomp_data + K)); */
|
|
PPC_LWZ_OFFS(r_A, r_skb, K);
|
|
break;
|
|
case BPF_LDX | BPF_W | BPF_LEN: /* X = skb->len; */
|
|
PPC_LWZ_OFFS(r_X, r_skb, offsetof(struct sk_buff, len));
|
|
break;
|
|
|
|
/*** Ancillary info loads ***/
|
|
case BPF_ANC | SKF_AD_PROTOCOL: /* A = ntohs(skb->protocol); */
|
|
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff,
|
|
protocol) != 2);
|
|
PPC_NTOHS_OFFS(r_A, r_skb, offsetof(struct sk_buff,
|
|
protocol));
|
|
break;
|
|
case BPF_ANC | SKF_AD_IFINDEX:
|
|
case BPF_ANC | SKF_AD_HATYPE:
|
|
BUILD_BUG_ON(FIELD_SIZEOF(struct net_device,
|
|
ifindex) != 4);
|
|
BUILD_BUG_ON(FIELD_SIZEOF(struct net_device,
|
|
type) != 2);
|
|
PPC_LL_OFFS(r_scratch1, r_skb, offsetof(struct sk_buff,
|
|
dev));
|
|
PPC_CMPDI(r_scratch1, 0);
|
|
if (ctx->pc_ret0 != -1) {
|
|
PPC_BCC(COND_EQ, addrs[ctx->pc_ret0]);
|
|
} else {
|
|
/* Exit, returning 0; first pass hits here. */
|
|
PPC_BCC_SHORT(COND_NE, ctx->idx * 4 + 12);
|
|
PPC_LI(r_ret, 0);
|
|
PPC_JMP(exit_addr);
|
|
}
|
|
if (code == (BPF_ANC | SKF_AD_IFINDEX)) {
|
|
PPC_LWZ_OFFS(r_A, r_scratch1,
|
|
offsetof(struct net_device, ifindex));
|
|
} else {
|
|
PPC_LHZ_OFFS(r_A, r_scratch1,
|
|
offsetof(struct net_device, type));
|
|
}
|
|
|
|
break;
|
|
case BPF_ANC | SKF_AD_MARK:
|
|
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);
|
|
PPC_LWZ_OFFS(r_A, r_skb, offsetof(struct sk_buff,
|
|
mark));
|
|
break;
|
|
case BPF_ANC | SKF_AD_RXHASH:
|
|
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4);
|
|
PPC_LWZ_OFFS(r_A, r_skb, offsetof(struct sk_buff,
|
|
hash));
|
|
break;
|
|
case BPF_ANC | SKF_AD_VLAN_TAG:
|
|
case BPF_ANC | SKF_AD_VLAN_TAG_PRESENT:
|
|
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2);
|
|
BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000);
|
|
|
|
PPC_LHZ_OFFS(r_A, r_skb, offsetof(struct sk_buff,
|
|
vlan_tci));
|
|
if (code == (BPF_ANC | SKF_AD_VLAN_TAG)) {
|
|
PPC_ANDI(r_A, r_A, ~VLAN_TAG_PRESENT);
|
|
} else {
|
|
PPC_ANDI(r_A, r_A, VLAN_TAG_PRESENT);
|
|
PPC_SRWI(r_A, r_A, 12);
|
|
}
|
|
break;
|
|
case BPF_ANC | SKF_AD_QUEUE:
|
|
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff,
|
|
queue_mapping) != 2);
|
|
PPC_LHZ_OFFS(r_A, r_skb, offsetof(struct sk_buff,
|
|
queue_mapping));
|
|
break;
|
|
case BPF_ANC | SKF_AD_PKTTYPE:
|
|
PPC_LBZ_OFFS(r_A, r_skb, PKT_TYPE_OFFSET());
|
|
PPC_ANDI(r_A, r_A, PKT_TYPE_MAX);
|
|
PPC_SRWI(r_A, r_A, 5);
|
|
break;
|
|
case BPF_ANC | SKF_AD_CPU:
|
|
PPC_BPF_LOAD_CPU(r_A);
|
|
break;
|
|
/*** Absolute loads from packet header/data ***/
|
|
case BPF_LD | BPF_W | BPF_ABS:
|
|
func = CHOOSE_LOAD_FUNC(K, sk_load_word);
|
|
goto common_load;
|
|
case BPF_LD | BPF_H | BPF_ABS:
|
|
func = CHOOSE_LOAD_FUNC(K, sk_load_half);
|
|
goto common_load;
|
|
case BPF_LD | BPF_B | BPF_ABS:
|
|
func = CHOOSE_LOAD_FUNC(K, sk_load_byte);
|
|
common_load:
|
|
/* Load from [K]. */
|
|
ctx->seen |= SEEN_DATAREF;
|
|
PPC_FUNC_ADDR(r_scratch1, func);
|
|
PPC_MTLR(r_scratch1);
|
|
PPC_LI32(r_addr, K);
|
|
PPC_BLRL();
|
|
/*
|
|
* Helper returns 'lt' condition on error, and an
|
|
* appropriate return value in r3
|
|
*/
|
|
PPC_BCC(COND_LT, exit_addr);
|
|
break;
|
|
|
|
/*** Indirect loads from packet header/data ***/
|
|
case BPF_LD | BPF_W | BPF_IND:
|
|
func = sk_load_word;
|
|
goto common_load_ind;
|
|
case BPF_LD | BPF_H | BPF_IND:
|
|
func = sk_load_half;
|
|
goto common_load_ind;
|
|
case BPF_LD | BPF_B | BPF_IND:
|
|
func = sk_load_byte;
|
|
common_load_ind:
|
|
/*
|
|
* Load from [X + K]. Negative offsets are tested for
|
|
* in the helper functions.
|
|
*/
|
|
ctx->seen |= SEEN_DATAREF | SEEN_XREG;
|
|
PPC_FUNC_ADDR(r_scratch1, func);
|
|
PPC_MTLR(r_scratch1);
|
|
PPC_ADDI(r_addr, r_X, IMM_L(K));
|
|
if (K >= 32768)
|
|
PPC_ADDIS(r_addr, r_addr, IMM_HA(K));
|
|
PPC_BLRL();
|
|
/* If error, cr0.LT set */
|
|
PPC_BCC(COND_LT, exit_addr);
|
|
break;
|
|
|
|
case BPF_LDX | BPF_B | BPF_MSH:
|
|
func = CHOOSE_LOAD_FUNC(K, sk_load_byte_msh);
|
|
goto common_load;
|
|
break;
|
|
|
|
/*** Jump and branches ***/
|
|
case BPF_JMP | BPF_JA:
|
|
if (K != 0)
|
|
PPC_JMP(addrs[i + 1 + K]);
|
|
break;
|
|
|
|
case BPF_JMP | BPF_JGT | BPF_K:
|
|
case BPF_JMP | BPF_JGT | BPF_X:
|
|
true_cond = COND_GT;
|
|
goto cond_branch;
|
|
case BPF_JMP | BPF_JGE | BPF_K:
|
|
case BPF_JMP | BPF_JGE | BPF_X:
|
|
true_cond = COND_GE;
|
|
goto cond_branch;
|
|
case BPF_JMP | BPF_JEQ | BPF_K:
|
|
case BPF_JMP | BPF_JEQ | BPF_X:
|
|
true_cond = COND_EQ;
|
|
goto cond_branch;
|
|
case BPF_JMP | BPF_JSET | BPF_K:
|
|
case BPF_JMP | BPF_JSET | BPF_X:
|
|
true_cond = COND_NE;
|
|
/* Fall through */
|
|
cond_branch:
|
|
/* same targets, can avoid doing the test :) */
|
|
if (filter[i].jt == filter[i].jf) {
|
|
if (filter[i].jt > 0)
|
|
PPC_JMP(addrs[i + 1 + filter[i].jt]);
|
|
break;
|
|
}
|
|
|
|
switch (code) {
|
|
case BPF_JMP | BPF_JGT | BPF_X:
|
|
case BPF_JMP | BPF_JGE | BPF_X:
|
|
case BPF_JMP | BPF_JEQ | BPF_X:
|
|
ctx->seen |= SEEN_XREG;
|
|
PPC_CMPLW(r_A, r_X);
|
|
break;
|
|
case BPF_JMP | BPF_JSET | BPF_X:
|
|
ctx->seen |= SEEN_XREG;
|
|
PPC_AND_DOT(r_scratch1, r_A, r_X);
|
|
break;
|
|
case BPF_JMP | BPF_JEQ | BPF_K:
|
|
case BPF_JMP | BPF_JGT | BPF_K:
|
|
case BPF_JMP | BPF_JGE | BPF_K:
|
|
if (K < 32768)
|
|
PPC_CMPLWI(r_A, K);
|
|
else {
|
|
PPC_LI32(r_scratch1, K);
|
|
PPC_CMPLW(r_A, r_scratch1);
|
|
}
|
|
break;
|
|
case BPF_JMP | BPF_JSET | BPF_K:
|
|
if (K < 32768)
|
|
/* PPC_ANDI is /only/ dot-form */
|
|
PPC_ANDI(r_scratch1, r_A, K);
|
|
else {
|
|
PPC_LI32(r_scratch1, K);
|
|
PPC_AND_DOT(r_scratch1, r_A,
|
|
r_scratch1);
|
|
}
|
|
break;
|
|
}
|
|
/* Sometimes branches are constructed "backward", with
|
|
* the false path being the branch and true path being
|
|
* a fallthrough to the next instruction.
|
|
*/
|
|
if (filter[i].jt == 0)
|
|
/* Swap the sense of the branch */
|
|
PPC_BCC(true_cond ^ COND_CMP_TRUE,
|
|
addrs[i + 1 + filter[i].jf]);
|
|
else {
|
|
PPC_BCC(true_cond, addrs[i + 1 + filter[i].jt]);
|
|
if (filter[i].jf != 0)
|
|
PPC_JMP(addrs[i + 1 + filter[i].jf]);
|
|
}
|
|
break;
|
|
default:
|
|
/* The filter contains something cruel & unusual.
|
|
* We don't handle it, but also there shouldn't be
|
|
* anything missing from our list.
|
|
*/
|
|
if (printk_ratelimit())
|
|
pr_err("BPF filter opcode %04x (@%d) unsupported\n",
|
|
filter[i].code, i);
|
|
return -ENOTSUPP;
|
|
}
|
|
|
|
}
|
|
/* Set end-of-body-code address for exit. */
|
|
addrs[i] = ctx->idx * 4;
|
|
|
|
return 0;
|
|
}
|
|
|
|
void bpf_jit_compile(struct bpf_prog *fp)
|
|
{
|
|
unsigned int proglen;
|
|
unsigned int alloclen;
|
|
u32 *image = NULL;
|
|
u32 *code_base;
|
|
unsigned int *addrs;
|
|
struct codegen_context cgctx;
|
|
int pass;
|
|
int flen = fp->len;
|
|
|
|
if (!bpf_jit_enable)
|
|
return;
|
|
|
|
addrs = kcalloc(flen + 1, sizeof(*addrs), GFP_KERNEL);
|
|
if (addrs == NULL)
|
|
return;
|
|
|
|
/*
|
|
* There are multiple assembly passes as the generated code will change
|
|
* size as it settles down, figuring out the max branch offsets/exit
|
|
* paths required.
|
|
*
|
|
* The range of standard conditional branches is +/- 32Kbytes. Since
|
|
* BPF_MAXINSNS = 4096, we can only jump from (worst case) start to
|
|
* finish with 8 bytes/instruction. Not feasible, so long jumps are
|
|
* used, distinct from short branches.
|
|
*
|
|
* Current:
|
|
*
|
|
* For now, both branch types assemble to 2 words (short branches padded
|
|
* with a NOP); this is less efficient, but assembly will always complete
|
|
* after exactly 3 passes:
|
|
*
|
|
* First pass: No code buffer; Program is "faux-generated" -- no code
|
|
* emitted but maximum size of output determined (and addrs[] filled
|
|
* in). Also, we note whether we use M[], whether we use skb data, etc.
|
|
* All generation choices assumed to be 'worst-case', e.g. branches all
|
|
* far (2 instructions), return path code reduction not available, etc.
|
|
*
|
|
* Second pass: Code buffer allocated with size determined previously.
|
|
* Prologue generated to support features we have seen used. Exit paths
|
|
* determined and addrs[] is filled in again, as code may be slightly
|
|
* smaller as a result.
|
|
*
|
|
* Third pass: Code generated 'for real', and branch destinations
|
|
* determined from now-accurate addrs[] map.
|
|
*
|
|
* Ideal:
|
|
*
|
|
* If we optimise this, near branches will be shorter. On the
|
|
* first assembly pass, we should err on the side of caution and
|
|
* generate the biggest code. On subsequent passes, branches will be
|
|
* generated short or long and code size will reduce. With smaller
|
|
* code, more branches may fall into the short category, and code will
|
|
* reduce more.
|
|
*
|
|
* Finally, if we see one pass generate code the same size as the
|
|
* previous pass we have converged and should now generate code for
|
|
* real. Allocating at the end will also save the memory that would
|
|
* otherwise be wasted by the (small) current code shrinkage.
|
|
* Preferably, we should do a small number of passes (e.g. 5) and if we
|
|
* haven't converged by then, get impatient and force code to generate
|
|
* as-is, even if the odd branch would be left long. The chances of a
|
|
* long jump are tiny with all but the most enormous of BPF filter
|
|
* inputs, so we should usually converge on the third pass.
|
|
*/
|
|
|
|
cgctx.idx = 0;
|
|
cgctx.seen = 0;
|
|
cgctx.pc_ret0 = -1;
|
|
/* Scouting faux-generate pass 0 */
|
|
if (bpf_jit_build_body(fp, 0, &cgctx, addrs))
|
|
/* We hit something illegal or unsupported. */
|
|
goto out;
|
|
|
|
/*
|
|
* Pretend to build prologue, given the features we've seen. This will
|
|
* update ctgtx.idx as it pretends to output instructions, then we can
|
|
* calculate total size from idx.
|
|
*/
|
|
bpf_jit_build_prologue(fp, 0, &cgctx);
|
|
bpf_jit_build_epilogue(0, &cgctx);
|
|
|
|
proglen = cgctx.idx * 4;
|
|
alloclen = proglen + FUNCTION_DESCR_SIZE;
|
|
image = module_alloc(alloclen);
|
|
if (!image)
|
|
goto out;
|
|
|
|
code_base = image + (FUNCTION_DESCR_SIZE/4);
|
|
|
|
/* Code generation passes 1-2 */
|
|
for (pass = 1; pass < 3; pass++) {
|
|
/* Now build the prologue, body code & epilogue for real. */
|
|
cgctx.idx = 0;
|
|
bpf_jit_build_prologue(fp, code_base, &cgctx);
|
|
bpf_jit_build_body(fp, code_base, &cgctx, addrs);
|
|
bpf_jit_build_epilogue(code_base, &cgctx);
|
|
|
|
if (bpf_jit_enable > 1)
|
|
pr_info("Pass %d: shrink = %d, seen = 0x%x\n", pass,
|
|
proglen - (cgctx.idx * 4), cgctx.seen);
|
|
}
|
|
|
|
if (bpf_jit_enable > 1)
|
|
/* Note that we output the base address of the code_base
|
|
* rather than image, since opcodes are in code_base.
|
|
*/
|
|
bpf_jit_dump(flen, proglen, pass, code_base);
|
|
|
|
bpf_flush_icache(code_base, code_base + (proglen/4));
|
|
|
|
#ifdef CONFIG_PPC64
|
|
/* Function descriptor nastiness: Address + TOC */
|
|
((u64 *)image)[0] = (u64)code_base;
|
|
((u64 *)image)[1] = local_paca->kernel_toc;
|
|
#endif
|
|
|
|
fp->bpf_func = (void *)image;
|
|
fp->jited = 1;
|
|
|
|
out:
|
|
kfree(addrs);
|
|
return;
|
|
}
|
|
|
|
void bpf_jit_free(struct bpf_prog *fp)
|
|
{
|
|
if (fp->jited)
|
|
module_memfree(fp->bpf_func);
|
|
|
|
bpf_prog_unlock_free(fp);
|
|
}
|