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-rw-r--r--arch/sparc/net/bpf_jit_comp_32.c766
1 files changed, 766 insertions, 0 deletions
diff --git a/arch/sparc/net/bpf_jit_comp_32.c b/arch/sparc/net/bpf_jit_comp_32.c
new file mode 100644
index 000000000000..d193748548e2
--- /dev/null
+++ b/arch/sparc/net/bpf_jit_comp_32.c
@@ -0,0 +1,766 @@
+#include <linux/moduleloader.h>
+#include <linux/workqueue.h>
+#include <linux/netdevice.h>
+#include <linux/filter.h>
+#include <linux/cache.h>
+#include <linux/if_vlan.h>
+
+#include <asm/cacheflush.h>
+#include <asm/ptrace.h>
+
+#include "bpf_jit_32.h"
+
+int bpf_jit_enable __read_mostly;
+
+static inline bool is_simm13(unsigned int value)
+{
+ return value + 0x1000 < 0x2000;
+}
+
+#define SEEN_DATAREF 1 /* might call external helpers */
+#define SEEN_XREG 2 /* ebx is used */
+#define SEEN_MEM 4 /* use mem[] for temporary storage */
+
+#define S13(X) ((X) & 0x1fff)
+#define IMMED 0x00002000
+#define RD(X) ((X) << 25)
+#define RS1(X) ((X) << 14)
+#define RS2(X) ((X))
+#define OP(X) ((X) << 30)
+#define OP2(X) ((X) << 22)
+#define OP3(X) ((X) << 19)
+#define COND(X) ((X) << 25)
+#define F1(X) OP(X)
+#define F2(X, Y) (OP(X) | OP2(Y))
+#define F3(X, Y) (OP(X) | OP3(Y))
+
+#define CONDN COND(0x0)
+#define CONDE COND(0x1)
+#define CONDLE COND(0x2)
+#define CONDL COND(0x3)
+#define CONDLEU COND(0x4)
+#define CONDCS COND(0x5)
+#define CONDNEG COND(0x6)
+#define CONDVC COND(0x7)
+#define CONDA COND(0x8)
+#define CONDNE COND(0x9)
+#define CONDG COND(0xa)
+#define CONDGE COND(0xb)
+#define CONDGU COND(0xc)
+#define CONDCC COND(0xd)
+#define CONDPOS COND(0xe)
+#define CONDVS COND(0xf)
+
+#define CONDGEU CONDCC
+#define CONDLU CONDCS
+
+#define WDISP22(X) (((X) >> 2) & 0x3fffff)
+
+#define BA (F2(0, 2) | CONDA)
+#define BGU (F2(0, 2) | CONDGU)
+#define BLEU (F2(0, 2) | CONDLEU)
+#define BGEU (F2(0, 2) | CONDGEU)
+#define BLU (F2(0, 2) | CONDLU)
+#define BE (F2(0, 2) | CONDE)
+#define BNE (F2(0, 2) | CONDNE)
+
+#define BE_PTR BE
+
+#define SETHI(K, REG) \
+ (F2(0, 0x4) | RD(REG) | (((K) >> 10) & 0x3fffff))
+#define OR_LO(K, REG) \
+ (F3(2, 0x02) | IMMED | RS1(REG) | ((K) & 0x3ff) | RD(REG))
+
+#define ADD F3(2, 0x00)
+#define AND F3(2, 0x01)
+#define ANDCC F3(2, 0x11)
+#define OR F3(2, 0x02)
+#define XOR F3(2, 0x03)
+#define SUB F3(2, 0x04)
+#define SUBCC F3(2, 0x14)
+#define MUL F3(2, 0x0a) /* umul */
+#define DIV F3(2, 0x0e) /* udiv */
+#define SLL F3(2, 0x25)
+#define SRL F3(2, 0x26)
+#define JMPL F3(2, 0x38)
+#define CALL F1(1)
+#define BR F2(0, 0x01)
+#define RD_Y F3(2, 0x28)
+#define WR_Y F3(2, 0x30)
+
+#define LD32 F3(3, 0x00)
+#define LD8 F3(3, 0x01)
+#define LD16 F3(3, 0x02)
+#define LD64 F3(3, 0x0b)
+#define ST32 F3(3, 0x04)
+
+#define LDPTR LD32
+#define BASE_STACKFRAME 96
+
+#define LD32I (LD32 | IMMED)
+#define LD8I (LD8 | IMMED)
+#define LD16I (LD16 | IMMED)
+#define LD64I (LD64 | IMMED)
+#define LDPTRI (LDPTR | IMMED)
+#define ST32I (ST32 | IMMED)
+
+#define emit_nop() \
+do { \
+ *prog++ = SETHI(0, G0); \
+} while (0)
+
+#define emit_neg() \
+do { /* sub %g0, r_A, r_A */ \
+ *prog++ = SUB | RS1(G0) | RS2(r_A) | RD(r_A); \
+} while (0)
+
+#define emit_reg_move(FROM, TO) \
+do { /* or %g0, FROM, TO */ \
+ *prog++ = OR | RS1(G0) | RS2(FROM) | RD(TO); \
+} while (0)
+
+#define emit_clear(REG) \
+do { /* or %g0, %g0, REG */ \
+ *prog++ = OR | RS1(G0) | RS2(G0) | RD(REG); \
+} while (0)
+
+#define emit_set_const(K, REG) \
+do { /* sethi %hi(K), REG */ \
+ *prog++ = SETHI(K, REG); \
+ /* or REG, %lo(K), REG */ \
+ *prog++ = OR_LO(K, REG); \
+} while (0)
+
+ /* Emit
+ *
+ * OP r_A, r_X, r_A
+ */
+#define emit_alu_X(OPCODE) \
+do { \
+ seen |= SEEN_XREG; \
+ *prog++ = OPCODE | RS1(r_A) | RS2(r_X) | RD(r_A); \
+} while (0)
+
+ /* Emit either:
+ *
+ * OP r_A, K, r_A
+ *
+ * or
+ *
+ * sethi %hi(K), r_TMP
+ * or r_TMP, %lo(K), r_TMP
+ * OP r_A, r_TMP, r_A
+ *
+ * depending upon whether K fits in a signed 13-bit
+ * immediate instruction field. Emit nothing if K
+ * is zero.
+ */
+#define emit_alu_K(OPCODE, K) \
+do { \
+ if (K || OPCODE == AND || OPCODE == MUL) { \
+ unsigned int _insn = OPCODE; \
+ _insn |= RS1(r_A) | RD(r_A); \
+ if (is_simm13(K)) { \
+ *prog++ = _insn | IMMED | S13(K); \
+ } else { \
+ emit_set_const(K, r_TMP); \
+ *prog++ = _insn | RS2(r_TMP); \
+ } \
+ } \
+} while (0)
+
+#define emit_loadimm(K, DEST) \
+do { \
+ if (is_simm13(K)) { \
+ /* or %g0, K, DEST */ \
+ *prog++ = OR | IMMED | RS1(G0) | S13(K) | RD(DEST); \
+ } else { \
+ emit_set_const(K, DEST); \
+ } \
+} while (0)
+
+#define emit_loadptr(BASE, STRUCT, FIELD, DEST) \
+do { unsigned int _off = offsetof(STRUCT, FIELD); \
+ BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(void *)); \
+ *prog++ = LDPTRI | RS1(BASE) | S13(_off) | RD(DEST); \
+} while (0)
+
+#define emit_load32(BASE, STRUCT, FIELD, DEST) \
+do { unsigned int _off = offsetof(STRUCT, FIELD); \
+ BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(u32)); \
+ *prog++ = LD32I | RS1(BASE) | S13(_off) | RD(DEST); \
+} while (0)
+
+#define emit_load16(BASE, STRUCT, FIELD, DEST) \
+do { unsigned int _off = offsetof(STRUCT, FIELD); \
+ BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(u16)); \
+ *prog++ = LD16I | RS1(BASE) | S13(_off) | RD(DEST); \
+} while (0)
+
+#define __emit_load8(BASE, STRUCT, FIELD, DEST) \
+do { unsigned int _off = offsetof(STRUCT, FIELD); \
+ *prog++ = LD8I | RS1(BASE) | S13(_off) | RD(DEST); \
+} while (0)
+
+#define emit_load8(BASE, STRUCT, FIELD, DEST) \
+do { BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(u8)); \
+ __emit_load8(BASE, STRUCT, FIELD, DEST); \
+} while (0)
+
+#define BIAS (-4)
+
+#define emit_ldmem(OFF, DEST) \
+do { *prog++ = LD32I | RS1(SP) | S13(BIAS - (OFF)) | RD(DEST); \
+} while (0)
+
+#define emit_stmem(OFF, SRC) \
+do { *prog++ = ST32I | RS1(SP) | S13(BIAS - (OFF)) | RD(SRC); \
+} while (0)
+
+#ifdef CONFIG_SMP
+#define emit_load_cpu(REG) \
+ emit_load32(G6, struct thread_info, cpu, REG)
+#else
+#define emit_load_cpu(REG) emit_clear(REG)
+#endif
+
+#define emit_skb_loadptr(FIELD, DEST) \
+ emit_loadptr(r_SKB, struct sk_buff, FIELD, DEST)
+#define emit_skb_load32(FIELD, DEST) \
+ emit_load32(r_SKB, struct sk_buff, FIELD, DEST)
+#define emit_skb_load16(FIELD, DEST) \
+ emit_load16(r_SKB, struct sk_buff, FIELD, DEST)
+#define __emit_skb_load8(FIELD, DEST) \
+ __emit_load8(r_SKB, struct sk_buff, FIELD, DEST)
+#define emit_skb_load8(FIELD, DEST) \
+ emit_load8(r_SKB, struct sk_buff, FIELD, DEST)
+
+#define emit_jmpl(BASE, IMM_OFF, LREG) \
+ *prog++ = (JMPL | IMMED | RS1(BASE) | S13(IMM_OFF) | RD(LREG))
+
+#define emit_call(FUNC) \
+do { void *_here = image + addrs[i] - 8; \
+ unsigned int _off = (void *)(FUNC) - _here; \
+ *prog++ = CALL | (((_off) >> 2) & 0x3fffffff); \
+ emit_nop(); \
+} while (0)
+
+#define emit_branch(BR_OPC, DEST) \
+do { unsigned int _here = addrs[i] - 8; \
+ *prog++ = BR_OPC | WDISP22((DEST) - _here); \
+} while (0)
+
+#define emit_branch_off(BR_OPC, OFF) \
+do { *prog++ = BR_OPC | WDISP22(OFF); \
+} while (0)
+
+#define emit_jump(DEST) emit_branch(BA, DEST)
+
+#define emit_read_y(REG) *prog++ = RD_Y | RD(REG)
+#define emit_write_y(REG) *prog++ = WR_Y | IMMED | RS1(REG) | S13(0)
+
+#define emit_cmp(R1, R2) \
+ *prog++ = (SUBCC | RS1(R1) | RS2(R2) | RD(G0))
+
+#define emit_cmpi(R1, IMM) \
+ *prog++ = (SUBCC | IMMED | RS1(R1) | S13(IMM) | RD(G0));
+
+#define emit_btst(R1, R2) \
+ *prog++ = (ANDCC | RS1(R1) | RS2(R2) | RD(G0))
+
+#define emit_btsti(R1, IMM) \
+ *prog++ = (ANDCC | IMMED | RS1(R1) | S13(IMM) | RD(G0));
+
+#define emit_sub(R1, R2, R3) \
+ *prog++ = (SUB | RS1(R1) | RS2(R2) | RD(R3))
+
+#define emit_subi(R1, IMM, R3) \
+ *prog++ = (SUB | IMMED | RS1(R1) | S13(IMM) | RD(R3))
+
+#define emit_add(R1, R2, R3) \
+ *prog++ = (ADD | RS1(R1) | RS2(R2) | RD(R3))
+
+#define emit_addi(R1, IMM, R3) \
+ *prog++ = (ADD | IMMED | RS1(R1) | S13(IMM) | RD(R3))
+
+#define emit_and(R1, R2, R3) \
+ *prog++ = (AND | RS1(R1) | RS2(R2) | RD(R3))
+
+#define emit_andi(R1, IMM, R3) \
+ *prog++ = (AND | IMMED | RS1(R1) | S13(IMM) | RD(R3))
+
+#define emit_alloc_stack(SZ) \
+ *prog++ = (SUB | IMMED | RS1(SP) | S13(SZ) | RD(SP))
+
+#define emit_release_stack(SZ) \
+ *prog++ = (ADD | IMMED | RS1(SP) | S13(SZ) | RD(SP))
+
+/* A note about branch offset calculations. The addrs[] array,
+ * indexed by BPF instruction, records the address after all the
+ * sparc instructions emitted for that BPF instruction.
+ *
+ * The most common case is to emit a branch at the end of such
+ * a code sequence. So this would be two instructions, the
+ * branch and it's delay slot.
+ *
+ * Therefore by default the branch emitters calculate the branch
+ * offset field as:
+ *
+ * destination - (addrs[i] - 8)
+ *
+ * This "addrs[i] - 8" is the address of the branch itself or
+ * what "." would be in assembler notation. The "8" part is
+ * how we take into consideration the branch and it's delay
+ * slot mentioned above.
+ *
+ * Sometimes we need to emit a branch earlier in the code
+ * sequence. And in these situations we adjust "destination"
+ * to accommodate this difference. For example, if we needed
+ * to emit a branch (and it's delay slot) right before the
+ * final instruction emitted for a BPF opcode, we'd use
+ * "destination + 4" instead of just plain "destination" above.
+ *
+ * This is why you see all of these funny emit_branch() and
+ * emit_jump() calls with adjusted offsets.
+ */
+
+void bpf_jit_compile(struct bpf_prog *fp)
+{
+ unsigned int cleanup_addr, proglen, oldproglen = 0;
+ u32 temp[8], *prog, *func, seen = 0, pass;
+ const struct sock_filter *filter = fp->insns;
+ int i, flen = fp->len, pc_ret0 = -1;
+ unsigned int *addrs;
+ void *image;
+
+ if (!bpf_jit_enable)
+ return;
+
+ addrs = kmalloc(flen * sizeof(*addrs), GFP_KERNEL);
+ if (addrs == NULL)
+ return;
+
+ /* Before first pass, make a rough estimation of addrs[]
+ * each bpf instruction is translated to less than 64 bytes
+ */
+ for (proglen = 0, i = 0; i < flen; i++) {
+ proglen += 64;
+ addrs[i] = proglen;
+ }
+ cleanup_addr = proglen; /* epilogue address */
+ image = NULL;
+ for (pass = 0; pass < 10; pass++) {
+ u8 seen_or_pass0 = (pass == 0) ? (SEEN_XREG | SEEN_DATAREF | SEEN_MEM) : seen;
+
+ /* no prologue/epilogue for trivial filters (RET something) */
+ proglen = 0;
+ prog = temp;
+
+ /* Prologue */
+ if (seen_or_pass0) {
+ if (seen_or_pass0 & SEEN_MEM) {
+ unsigned int sz = BASE_STACKFRAME;
+ sz += BPF_MEMWORDS * sizeof(u32);
+ emit_alloc_stack(sz);
+ }
+
+ /* Make sure we dont leek kernel memory. */
+ if (seen_or_pass0 & SEEN_XREG)
+ emit_clear(r_X);
+
+ /* If this filter needs to access skb data,
+ * load %o4 and %o5 with:
+ * %o4 = skb->len - skb->data_len
+ * %o5 = skb->data
+ * And also back up %o7 into r_saved_O7 so we can
+ * invoke the stubs using 'call'.
+ */
+ if (seen_or_pass0 & SEEN_DATAREF) {
+ emit_load32(r_SKB, struct sk_buff, len, r_HEADLEN);
+ emit_load32(r_SKB, struct sk_buff, data_len, r_TMP);
+ emit_sub(r_HEADLEN, r_TMP, r_HEADLEN);
+ emit_loadptr(r_SKB, struct sk_buff, data, r_SKB_DATA);
+ }
+ }
+ emit_reg_move(O7, r_saved_O7);
+
+ /* Make sure we dont leak kernel information to the user. */
+ if (bpf_needs_clear_a(&filter[0]))
+ emit_clear(r_A); /* A = 0 */
+
+ for (i = 0; i < flen; i++) {
+ unsigned int K = filter[i].k;
+ unsigned int t_offset;
+ unsigned int f_offset;
+ u32 t_op, f_op;
+ u16 code = bpf_anc_helper(&filter[i]);
+ int ilen;
+
+ switch (code) {
+ case BPF_ALU | BPF_ADD | BPF_X: /* A += X; */
+ emit_alu_X(ADD);
+ break;
+ case BPF_ALU | BPF_ADD | BPF_K: /* A += K; */
+ emit_alu_K(ADD, K);
+ break;
+ case BPF_ALU | BPF_SUB | BPF_X: /* A -= X; */
+ emit_alu_X(SUB);
+ break;
+ case BPF_ALU | BPF_SUB | BPF_K: /* A -= K */
+ emit_alu_K(SUB, K);
+ break;
+ case BPF_ALU | BPF_AND | BPF_X: /* A &= X */
+ emit_alu_X(AND);
+ break;
+ case BPF_ALU | BPF_AND | BPF_K: /* A &= K */
+ emit_alu_K(AND, K);
+ break;
+ case BPF_ALU | BPF_OR | BPF_X: /* A |= X */
+ emit_alu_X(OR);
+ break;
+ case BPF_ALU | BPF_OR | BPF_K: /* A |= K */
+ emit_alu_K(OR, K);
+ break;
+ case BPF_ANC | SKF_AD_ALU_XOR_X: /* A ^= X; */
+ case BPF_ALU | BPF_XOR | BPF_X:
+ emit_alu_X(XOR);
+ break;
+ case BPF_ALU | BPF_XOR | BPF_K: /* A ^= K */
+ emit_alu_K(XOR, K);
+ break;
+ case BPF_ALU | BPF_LSH | BPF_X: /* A <<= X */
+ emit_alu_X(SLL);
+ break;
+ case BPF_ALU | BPF_LSH | BPF_K: /* A <<= K */
+ emit_alu_K(SLL, K);
+ break;
+ case BPF_ALU | BPF_RSH | BPF_X: /* A >>= X */
+ emit_alu_X(SRL);
+ break;
+ case BPF_ALU | BPF_RSH | BPF_K: /* A >>= K */
+ emit_alu_K(SRL, K);
+ break;
+ case BPF_ALU | BPF_MUL | BPF_X: /* A *= X; */
+ emit_alu_X(MUL);
+ break;
+ case BPF_ALU | BPF_MUL | BPF_K: /* A *= K */
+ emit_alu_K(MUL, K);
+ break;
+ case BPF_ALU | BPF_DIV | BPF_K: /* A /= K with K != 0*/
+ if (K == 1)
+ break;
+ emit_write_y(G0);
+ /* The Sparc v8 architecture requires
+ * three instructions between a %y
+ * register write and the first use.
+ */
+ emit_nop();
+ emit_nop();
+ emit_nop();
+ emit_alu_K(DIV, K);
+ break;
+ case BPF_ALU | BPF_DIV | BPF_X: /* A /= X; */
+ emit_cmpi(r_X, 0);
+ if (pc_ret0 > 0) {
+ t_offset = addrs[pc_ret0 - 1];
+ emit_branch(BE, t_offset + 20);
+ emit_nop(); /* delay slot */
+ } else {
+ emit_branch_off(BNE, 16);
+ emit_nop();
+ emit_jump(cleanup_addr + 20);
+ emit_clear(r_A);
+ }
+ emit_write_y(G0);
+ /* The Sparc v8 architecture requires
+ * three instructions between a %y
+ * register write and the first use.
+ */
+ emit_nop();
+ emit_nop();
+ emit_nop();
+ emit_alu_X(DIV);
+ break;
+ case BPF_ALU | BPF_NEG:
+ emit_neg();
+ break;
+ case BPF_RET | BPF_K:
+ if (!K) {
+ if (pc_ret0 == -1)
+ pc_ret0 = i;
+ emit_clear(r_A);
+ } else {
+ emit_loadimm(K, r_A);
+ }
+ /* Fallthrough */
+ case BPF_RET | BPF_A:
+ if (seen_or_pass0) {
+ if (i != flen - 1) {
+ emit_jump(cleanup_addr);
+ emit_nop();
+ break;
+ }
+ if (seen_or_pass0 & SEEN_MEM) {
+ unsigned int sz = BASE_STACKFRAME;
+ sz += BPF_MEMWORDS * sizeof(u32);
+ emit_release_stack(sz);
+ }
+ }
+ /* jmpl %r_saved_O7 + 8, %g0 */
+ emit_jmpl(r_saved_O7, 8, G0);
+ emit_reg_move(r_A, O0); /* delay slot */
+ break;
+ case BPF_MISC | BPF_TAX:
+ seen |= SEEN_XREG;
+ emit_reg_move(r_A, r_X);
+ break;
+ case BPF_MISC | BPF_TXA:
+ seen |= SEEN_XREG;
+ emit_reg_move(r_X, r_A);
+ break;
+ case BPF_ANC | SKF_AD_CPU:
+ emit_load_cpu(r_A);
+ break;
+ case BPF_ANC | SKF_AD_PROTOCOL:
+ emit_skb_load16(protocol, r_A);
+ break;
+ case BPF_ANC | SKF_AD_PKTTYPE:
+ __emit_skb_load8(__pkt_type_offset, r_A);
+ emit_andi(r_A, PKT_TYPE_MAX, r_A);
+ emit_alu_K(SRL, 5);
+ break;
+ case BPF_ANC | SKF_AD_IFINDEX:
+ emit_skb_loadptr(dev, r_A);
+ emit_cmpi(r_A, 0);
+ emit_branch(BE_PTR, cleanup_addr + 4);
+ emit_nop();
+ emit_load32(r_A, struct net_device, ifindex, r_A);
+ break;
+ case BPF_ANC | SKF_AD_MARK:
+ emit_skb_load32(mark, r_A);
+ break;
+ case BPF_ANC | SKF_AD_QUEUE:
+ emit_skb_load16(queue_mapping, r_A);
+ break;
+ case BPF_ANC | SKF_AD_HATYPE:
+ emit_skb_loadptr(dev, r_A);
+ emit_cmpi(r_A, 0);
+ emit_branch(BE_PTR, cleanup_addr + 4);
+ emit_nop();
+ emit_load16(r_A, struct net_device, type, r_A);
+ break;
+ case BPF_ANC | SKF_AD_RXHASH:
+ emit_skb_load32(hash, r_A);
+ break;
+ case BPF_ANC | SKF_AD_VLAN_TAG:
+ case BPF_ANC | SKF_AD_VLAN_TAG_PRESENT:
+ emit_skb_load16(vlan_tci, r_A);
+ if (code != (BPF_ANC | SKF_AD_VLAN_TAG)) {
+ emit_alu_K(SRL, 12);
+ emit_andi(r_A, 1, r_A);
+ } else {
+ emit_loadimm(~VLAN_TAG_PRESENT, r_TMP);
+ emit_and(r_A, r_TMP, r_A);
+ }
+ break;
+ case BPF_LD | BPF_W | BPF_LEN:
+ emit_skb_load32(len, r_A);
+ break;
+ case BPF_LDX | BPF_W | BPF_LEN:
+ emit_skb_load32(len, r_X);
+ break;
+ case BPF_LD | BPF_IMM:
+ emit_loadimm(K, r_A);
+ break;
+ case BPF_LDX | BPF_IMM:
+ emit_loadimm(K, r_X);
+ break;
+ case BPF_LD | BPF_MEM:
+ seen |= SEEN_MEM;
+ emit_ldmem(K * 4, r_A);
+ break;
+ case BPF_LDX | BPF_MEM:
+ seen |= SEEN_MEM | SEEN_XREG;
+ emit_ldmem(K * 4, r_X);
+ break;
+ case BPF_ST:
+ seen |= SEEN_MEM;
+ emit_stmem(K * 4, r_A);
+ break;
+ case BPF_STX:
+ seen |= SEEN_MEM | SEEN_XREG;
+ emit_stmem(K * 4, r_X);
+ break;
+
+#define CHOOSE_LOAD_FUNC(K, func) \
+ ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset)
+
+ case BPF_LD | BPF_W | BPF_ABS:
+ func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_word);
+common_load: seen |= SEEN_DATAREF;
+ emit_loadimm(K, r_OFF);
+ emit_call(func);
+ break;
+ case BPF_LD | BPF_H | BPF_ABS:
+ func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_half);
+ goto common_load;
+ case BPF_LD | BPF_B | BPF_ABS:
+ func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_byte);
+ goto common_load;
+ case BPF_LDX | BPF_B | BPF_MSH:
+ func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_byte_msh);
+ goto common_load;
+ case BPF_LD | BPF_W | BPF_IND:
+ func = bpf_jit_load_word;
+common_load_ind: seen |= SEEN_DATAREF | SEEN_XREG;
+ if (K) {
+ if (is_simm13(K)) {
+ emit_addi(r_X, K, r_OFF);
+ } else {
+ emit_loadimm(K, r_TMP);
+ emit_add(r_X, r_TMP, r_OFF);
+ }
+ } else {
+ emit_reg_move(r_X, r_OFF);
+ }
+ emit_call(func);
+ break;
+ case BPF_LD | BPF_H | BPF_IND:
+ func = bpf_jit_load_half;
+ goto common_load_ind;
+ case BPF_LD | BPF_B | BPF_IND:
+ func = bpf_jit_load_byte;
+ goto common_load_ind;
+ case BPF_JMP | BPF_JA:
+ emit_jump(addrs[i + K]);
+ emit_nop();
+ break;
+
+#define COND_SEL(CODE, TOP, FOP) \
+ case CODE: \
+ t_op = TOP; \
+ f_op = FOP; \
+ goto cond_branch
+
+ COND_SEL(BPF_JMP | BPF_JGT | BPF_K, BGU, BLEU);
+ COND_SEL(BPF_JMP | BPF_JGE | BPF_K, BGEU, BLU);
+ COND_SEL(BPF_JMP | BPF_JEQ | BPF_K, BE, BNE);
+ COND_SEL(BPF_JMP | BPF_JSET | BPF_K, BNE, BE);
+ COND_SEL(BPF_JMP | BPF_JGT | BPF_X, BGU, BLEU);
+ COND_SEL(BPF_JMP | BPF_JGE | BPF_X, BGEU, BLU);
+ COND_SEL(BPF_JMP | BPF_JEQ | BPF_X, BE, BNE);
+ COND_SEL(BPF_JMP | BPF_JSET | BPF_X, BNE, BE);
+
+cond_branch: f_offset = addrs[i + filter[i].jf];
+ t_offset = addrs[i + filter[i].jt];
+
+ /* same targets, can avoid doing the test :) */
+ if (filter[i].jt == filter[i].jf) {
+ emit_jump(t_offset);
+ emit_nop();
+ break;
+ }
+
+ switch (code) {
+ case BPF_JMP | BPF_JGT | BPF_X:
+ case BPF_JMP | BPF_JGE | BPF_X:
+ case BPF_JMP | BPF_JEQ | BPF_X:
+ seen |= SEEN_XREG;
+ emit_cmp(r_A, r_X);
+ break;
+ case BPF_JMP | BPF_JSET | BPF_X:
+ seen |= SEEN_XREG;
+ emit_btst(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 (is_simm13(K)) {
+ emit_cmpi(r_A, K);
+ } else {
+ emit_loadimm(K, r_TMP);
+ emit_cmp(r_A, r_TMP);
+ }
+ break;
+ case BPF_JMP | BPF_JSET | BPF_K:
+ if (is_simm13(K)) {
+ emit_btsti(r_A, K);
+ } else {
+ emit_loadimm(K, r_TMP);
+ emit_btst(r_A, r_TMP);
+ }
+ break;
+ }
+ if (filter[i].jt != 0) {
+ if (filter[i].jf)
+ t_offset += 8;
+ emit_branch(t_op, t_offset);
+ emit_nop(); /* delay slot */
+ if (filter[i].jf) {
+ emit_jump(f_offset);
+ emit_nop();
+ }
+ break;
+ }
+ emit_branch(f_op, f_offset);
+ emit_nop(); /* delay slot */
+ break;
+
+ default:
+ /* hmm, too complex filter, give up with jit compiler */
+ goto out;
+ }
+ ilen = (void *) prog - (void *) temp;
+ if (image) {
+ if (unlikely(proglen + ilen > oldproglen)) {
+ pr_err("bpb_jit_compile fatal error\n");
+ kfree(addrs);
+ module_memfree(image);
+ return;
+ }
+ memcpy(image + proglen, temp, ilen);
+ }
+ proglen += ilen;
+ addrs[i] = proglen;
+ prog = temp;
+ }
+ /* last bpf instruction is always a RET :
+ * use it to give the cleanup instruction(s) addr
+ */
+ cleanup_addr = proglen - 8; /* jmpl; mov r_A,%o0; */
+ if (seen_or_pass0 & SEEN_MEM)
+ cleanup_addr -= 4; /* add %sp, X, %sp; */
+
+ if (image) {
+ if (proglen != oldproglen)
+ pr_err("bpb_jit_compile proglen=%u != oldproglen=%u\n",
+ proglen, oldproglen);
+ break;
+ }
+ if (proglen == oldproglen) {
+ image = module_alloc(proglen);
+ if (!image)
+ goto out;
+ }
+ oldproglen = proglen;
+ }
+
+ if (bpf_jit_enable > 1)
+ bpf_jit_dump(flen, proglen, pass + 1, image);
+
+ if (image) {
+ 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);
+}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.