diff options
Diffstat (limited to 'arch/s390')
-rw-r--r-- | arch/s390/net/bpf_jit.h | 5 | ||||
-rw-r--r-- | arch/s390/net/bpf_jit_comp.c | 93 |
2 files changed, 55 insertions, 43 deletions
diff --git a/arch/s390/net/bpf_jit.h b/arch/s390/net/bpf_jit.h index f6498eec9ee1..f010c93a88b1 100644 --- a/arch/s390/net/bpf_jit.h +++ b/arch/s390/net/bpf_jit.h @@ -36,6 +36,8 @@ extern u8 sk_load_word[], sk_load_half[], sk_load_byte[]; * | BPF stack | | * | | | * +---------------+ | + * | 8 byte skbp | | + * R15+170 -> +---------------+ | * | 8 byte hlen | | * R15+168 -> +---------------+ | * | 4 byte align | | @@ -51,11 +53,12 @@ extern u8 sk_load_word[], sk_load_half[], sk_load_byte[]; * We get 160 bytes stack space from calling function, but only use * 12 * 8 byte for old backchain, r15..r6, and tail_call_cnt. */ -#define STK_SPACE (MAX_BPF_STACK + 8 + 4 + 4 + 160) +#define STK_SPACE (MAX_BPF_STACK + 8 + 8 + 4 + 4 + 160) #define STK_160_UNUSED (160 - 12 * 8) #define STK_OFF (STK_SPACE - STK_160_UNUSED) #define STK_OFF_TMP 160 /* Offset of tmp buffer on stack */ #define STK_OFF_HLEN 168 /* Offset of SKB header length on stack */ +#define STK_OFF_SKBP 170 /* Offset of SKB pointer on stack */ #define STK_OFF_R6 (160 - 11 * 8) /* Offset of r6 on stack */ #define STK_OFF_TCCNT (160 - 12 * 8) /* Offset of tail_call_cnt on stack */ diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index 8d2e5165865f..eeda051442c3 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -45,7 +45,7 @@ struct bpf_jit { int labels[1]; /* Labels for local jumps */ }; -#define BPF_SIZE_MAX 4096 /* Max size for program */ +#define BPF_SIZE_MAX 0x7ffff /* Max size for program (20 bit signed displ) */ #define SEEN_SKB 1 /* skb access */ #define SEEN_MEM 2 /* use mem[] for temporary storage */ @@ -53,6 +53,7 @@ struct bpf_jit { #define SEEN_LITERAL 8 /* code uses literals */ #define SEEN_FUNC 16 /* calls C functions */ #define SEEN_TAIL_CALL 32 /* code uses tail calls */ +#define SEEN_SKB_CHANGE 64 /* code changes skb data */ #define SEEN_STACK (SEEN_FUNC | SEEN_MEM | SEEN_SKB) /* @@ -203,19 +204,11 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1) _EMIT6(op1 | __disp, op2); \ }) -#define EMIT6_DISP(op1, op2, b1, b2, b3, disp) \ -({ \ - _EMIT6_DISP(op1 | reg(b1, b2) << 16 | \ - reg_high(b3) << 8, op2, disp); \ - REG_SET_SEEN(b1); \ - REG_SET_SEEN(b2); \ - REG_SET_SEEN(b3); \ -}) - #define _EMIT6_DISP_LH(op1, op2, disp) \ ({ \ - unsigned int __disp_h = ((u32)disp) & 0xff000; \ - unsigned int __disp_l = ((u32)disp) & 0x00fff; \ + u32 _disp = (u32) disp; \ + unsigned int __disp_h = _disp & 0xff000; \ + unsigned int __disp_l = _disp & 0x00fff; \ _EMIT6(op1 | __disp_l, op2 | __disp_h >> 4); \ }) @@ -390,12 +383,32 @@ static void save_restore_regs(struct bpf_jit *jit, int op) } /* + * For SKB access %b1 contains the SKB pointer. For "bpf_jit.S" + * we store the SKB header length on the stack and the SKB data + * pointer in REG_SKB_DATA. + */ +static void emit_load_skb_data_hlen(struct bpf_jit *jit) +{ + /* Header length: llgf %w1,<len>(%b1) */ + EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_1, + offsetof(struct sk_buff, len)); + /* s %w1,<data_len>(%b1) */ + EMIT4_DISP(0x5b000000, REG_W1, BPF_REG_1, + offsetof(struct sk_buff, data_len)); + /* stg %w1,ST_OFF_HLEN(%r0,%r15) */ + EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0, REG_15, STK_OFF_HLEN); + /* lg %skb_data,data_off(%b1) */ + EMIT6_DISP_LH(0xe3000000, 0x0004, REG_SKB_DATA, REG_0, + BPF_REG_1, offsetof(struct sk_buff, data)); +} + +/* * Emit function prologue * * Save registers and create stack frame if necessary. * See stack frame layout desription in "bpf_jit.h"! */ -static void bpf_jit_prologue(struct bpf_jit *jit) +static void bpf_jit_prologue(struct bpf_jit *jit, bool is_classic) { if (jit->seen & SEEN_TAIL_CALL) { /* xc STK_OFF_TCCNT(4,%r15),STK_OFF_TCCNT(%r15) */ @@ -429,32 +442,21 @@ static void bpf_jit_prologue(struct bpf_jit *jit) EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0, REG_15, 152); } - /* - * For SKB access %b1 contains the SKB pointer. For "bpf_jit.S" - * we store the SKB header length on the stack and the SKB data - * pointer in REG_SKB_DATA. - */ - if (jit->seen & SEEN_SKB) { - /* Header length: llgf %w1,<len>(%b1) */ - EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_1, - offsetof(struct sk_buff, len)); - /* s %w1,<data_len>(%b1) */ - EMIT4_DISP(0x5b000000, REG_W1, BPF_REG_1, - offsetof(struct sk_buff, data_len)); - /* stg %w1,ST_OFF_HLEN(%r0,%r15) */ + if (jit->seen & SEEN_SKB) + emit_load_skb_data_hlen(jit); + if (jit->seen & SEEN_SKB_CHANGE) + /* stg %b1,ST_OFF_SKBP(%r0,%r15) */ EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0, REG_15, - STK_OFF_HLEN); - /* lg %skb_data,data_off(%b1) */ - EMIT6_DISP_LH(0xe3000000, 0x0004, REG_SKB_DATA, REG_0, - BPF_REG_1, offsetof(struct sk_buff, data)); + STK_OFF_SKBP); + /* Clear A (%b0) and X (%b7) registers for converted BPF programs */ + if (is_classic) { + if (REG_SEEN(BPF_REG_A)) + /* lghi %ba,0 */ + EMIT4_IMM(0xa7090000, BPF_REG_A, 0); + if (REG_SEEN(BPF_REG_X)) + /* lghi %bx,0 */ + EMIT4_IMM(0xa7090000, BPF_REG_X, 0); } - /* BPF compatibility: clear A (%b0) and X (%b7) registers */ - if (REG_SEEN(BPF_REG_A)) - /* lghi %ba,0 */ - EMIT4_IMM(0xa7090000, BPF_REG_A, 0); - if (REG_SEEN(BPF_REG_X)) - /* lghi %bx,0 */ - EMIT4_IMM(0xa7090000, BPF_REG_X, 0); } /* @@ -976,12 +978,19 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i REG_SET_SEEN(BPF_REG_5); jit->seen |= SEEN_FUNC; /* lg %w1,<d(imm)>(%l) */ - EMIT6_DISP(0xe3000000, 0x0004, REG_W1, REG_0, REG_L, - EMIT_CONST_U64(func)); + EMIT6_DISP_LH(0xe3000000, 0x0004, REG_W1, REG_0, REG_L, + EMIT_CONST_U64(func)); /* basr %r14,%w1 */ EMIT2(0x0d00, REG_14, REG_W1); /* lgr %b0,%r2: load return value into %b0 */ EMIT4(0xb9040000, BPF_REG_0, REG_2); + if (bpf_helper_changes_skb_data((void *)func)) { + jit->seen |= SEEN_SKB_CHANGE; + /* lg %b1,ST_OFF_SKBP(%r15) */ + EMIT6_DISP_LH(0xe3000000, 0x0004, BPF_REG_1, REG_0, + REG_15, STK_OFF_SKBP); + emit_load_skb_data_hlen(jit); + } break; } case BPF_JMP | BPF_CALL | BPF_X: @@ -1023,7 +1032,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i MAX_TAIL_CALL_CNT, 0, 0x2); /* - * prog = array->prog[index]; + * prog = array->ptrs[index]; * if (prog == NULL) * goto out; */ @@ -1032,7 +1041,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i EMIT6_DISP_LH(0xeb000000, 0x000d, REG_1, BPF_REG_3, REG_0, 3); /* lg %r1,prog(%b2,%r1) */ EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, BPF_REG_2, - REG_1, offsetof(struct bpf_array, prog)); + REG_1, offsetof(struct bpf_array, ptrs)); /* clgij %r1,0,0x8,label0 */ EMIT6_PCREL_IMM_LABEL(0xec000000, 0x007d, REG_1, 0, 0, 0x8); @@ -1236,7 +1245,7 @@ static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp) jit->lit = jit->lit_start; jit->prg = 0; - bpf_jit_prologue(jit); + bpf_jit_prologue(jit, bpf_prog_was_classic(fp)); for (i = 0; i < fp->len; i += insn_count) { insn_count = bpf_jit_insn(jit, fp, i); if (insn_count < 0) |