diff options
Diffstat (limited to 'arch/s390/net/bpf_jit_comp.c')
| -rw-r--r-- | arch/s390/net/bpf_jit_comp.c | 55 |
1 files changed, 33 insertions, 22 deletions
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index 3dd0163..bbbac6d 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -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) /* @@ -382,6 +383,26 @@ 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. @@ -421,25 +442,12 @@ static void bpf_jit_prologue(struct bpf_jit *jit, bool is_classic) 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)) @@ -967,10 +975,6 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i */ const u64 func = (u64)__bpf_call_base + imm; - if (bpf_helper_changes_skb_data((void *)func)) - /* TODO reload skb->data, hlen */ - return -1; - REG_SET_SEEN(BPF_REG_5); jit->seen |= SEEN_FUNC; /* lg %w1,<d(imm)>(%l) */ @@ -980,6 +984,13 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i 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: |
