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-rw-r--r--arch/riscv/net/bpf_jit_comp64.c1825
1 files changed, 1825 insertions, 0 deletions
diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c
new file mode 100644
index 000000000000..aac190085472
--- /dev/null
+++ b/arch/riscv/net/bpf_jit_comp64.c
@@ -0,0 +1,1825 @@
+// SPDX-License-Identifier: GPL-2.0
+/* BPF JIT compiler for RV64G
+ *
+ * Copyright(c) 2019 Björn Töpel <bjorn.topel@gmail.com>
+ *
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <linux/memory.h>
+#include <linux/stop_machine.h>
+#include <asm/patch.h>
+#include <asm/cfi.h>
+#include "bpf_jit.h"
+
+#define RV_FENTRY_NINSNS 2
+
+#define RV_REG_TCC RV_REG_A6
+#define RV_REG_TCC_SAVED RV_REG_S6 /* Store A6 in S6 if program do calls */
+
+static const int regmap[] = {
+ [BPF_REG_0] = RV_REG_A5,
+ [BPF_REG_1] = RV_REG_A0,
+ [BPF_REG_2] = RV_REG_A1,
+ [BPF_REG_3] = RV_REG_A2,
+ [BPF_REG_4] = RV_REG_A3,
+ [BPF_REG_5] = RV_REG_A4,
+ [BPF_REG_6] = RV_REG_S1,
+ [BPF_REG_7] = RV_REG_S2,
+ [BPF_REG_8] = RV_REG_S3,
+ [BPF_REG_9] = RV_REG_S4,
+ [BPF_REG_FP] = RV_REG_S5,
+ [BPF_REG_AX] = RV_REG_T0,
+};
+
+static const int pt_regmap[] = {
+ [RV_REG_A0] = offsetof(struct pt_regs, a0),
+ [RV_REG_A1] = offsetof(struct pt_regs, a1),
+ [RV_REG_A2] = offsetof(struct pt_regs, a2),
+ [RV_REG_A3] = offsetof(struct pt_regs, a3),
+ [RV_REG_A4] = offsetof(struct pt_regs, a4),
+ [RV_REG_A5] = offsetof(struct pt_regs, a5),
+ [RV_REG_S1] = offsetof(struct pt_regs, s1),
+ [RV_REG_S2] = offsetof(struct pt_regs, s2),
+ [RV_REG_S3] = offsetof(struct pt_regs, s3),
+ [RV_REG_S4] = offsetof(struct pt_regs, s4),
+ [RV_REG_S5] = offsetof(struct pt_regs, s5),
+ [RV_REG_T0] = offsetof(struct pt_regs, t0),
+};
+
+enum {
+ RV_CTX_F_SEEN_TAIL_CALL = 0,
+ RV_CTX_F_SEEN_CALL = RV_REG_RA,
+ RV_CTX_F_SEEN_S1 = RV_REG_S1,
+ RV_CTX_F_SEEN_S2 = RV_REG_S2,
+ RV_CTX_F_SEEN_S3 = RV_REG_S3,
+ RV_CTX_F_SEEN_S4 = RV_REG_S4,
+ RV_CTX_F_SEEN_S5 = RV_REG_S5,
+ RV_CTX_F_SEEN_S6 = RV_REG_S6,
+};
+
+static u8 bpf_to_rv_reg(int bpf_reg, struct rv_jit_context *ctx)
+{
+ u8 reg = regmap[bpf_reg];
+
+ switch (reg) {
+ case RV_CTX_F_SEEN_S1:
+ case RV_CTX_F_SEEN_S2:
+ case RV_CTX_F_SEEN_S3:
+ case RV_CTX_F_SEEN_S4:
+ case RV_CTX_F_SEEN_S5:
+ case RV_CTX_F_SEEN_S6:
+ __set_bit(reg, &ctx->flags);
+ }
+ return reg;
+};
+
+static bool seen_reg(int reg, struct rv_jit_context *ctx)
+{
+ switch (reg) {
+ case RV_CTX_F_SEEN_CALL:
+ case RV_CTX_F_SEEN_S1:
+ case RV_CTX_F_SEEN_S2:
+ case RV_CTX_F_SEEN_S3:
+ case RV_CTX_F_SEEN_S4:
+ case RV_CTX_F_SEEN_S5:
+ case RV_CTX_F_SEEN_S6:
+ return test_bit(reg, &ctx->flags);
+ }
+ return false;
+}
+
+static void mark_fp(struct rv_jit_context *ctx)
+{
+ __set_bit(RV_CTX_F_SEEN_S5, &ctx->flags);
+}
+
+static void mark_call(struct rv_jit_context *ctx)
+{
+ __set_bit(RV_CTX_F_SEEN_CALL, &ctx->flags);
+}
+
+static bool seen_call(struct rv_jit_context *ctx)
+{
+ return test_bit(RV_CTX_F_SEEN_CALL, &ctx->flags);
+}
+
+static void mark_tail_call(struct rv_jit_context *ctx)
+{
+ __set_bit(RV_CTX_F_SEEN_TAIL_CALL, &ctx->flags);
+}
+
+static bool seen_tail_call(struct rv_jit_context *ctx)
+{
+ return test_bit(RV_CTX_F_SEEN_TAIL_CALL, &ctx->flags);
+}
+
+static u8 rv_tail_call_reg(struct rv_jit_context *ctx)
+{
+ mark_tail_call(ctx);
+
+ if (seen_call(ctx)) {
+ __set_bit(RV_CTX_F_SEEN_S6, &ctx->flags);
+ return RV_REG_S6;
+ }
+ return RV_REG_A6;
+}
+
+static bool is_32b_int(s64 val)
+{
+ return -(1L << 31) <= val && val < (1L << 31);
+}
+
+static bool in_auipc_jalr_range(s64 val)
+{
+ /*
+ * auipc+jalr can reach any signed PC-relative offset in the range
+ * [-2^31 - 2^11, 2^31 - 2^11).
+ */
+ return (-(1L << 31) - (1L << 11)) <= val &&
+ val < ((1L << 31) - (1L << 11));
+}
+
+/* Modify rd pointer to alternate reg to avoid corrupting original reg */
+static void emit_sextw_alt(u8 *rd, u8 ra, struct rv_jit_context *ctx)
+{
+ emit_sextw(ra, *rd, ctx);
+ *rd = ra;
+}
+
+static void emit_zextw_alt(u8 *rd, u8 ra, struct rv_jit_context *ctx)
+{
+ emit_zextw(ra, *rd, ctx);
+ *rd = ra;
+}
+
+/* Emit fixed-length instructions for address */
+static int emit_addr(u8 rd, u64 addr, bool extra_pass, struct rv_jit_context *ctx)
+{
+ /*
+ * Use the ro_insns(RX) to calculate the offset as the BPF program will
+ * finally run from this memory region.
+ */
+ u64 ip = (u64)(ctx->ro_insns + ctx->ninsns);
+ s64 off = addr - ip;
+ s64 upper = (off + (1 << 11)) >> 12;
+ s64 lower = off & 0xfff;
+
+ if (extra_pass && !in_auipc_jalr_range(off)) {
+ pr_err("bpf-jit: target offset 0x%llx is out of range\n", off);
+ return -ERANGE;
+ }
+
+ emit(rv_auipc(rd, upper), ctx);
+ emit(rv_addi(rd, rd, lower), ctx);
+ return 0;
+}
+
+/* Emit variable-length instructions for 32-bit and 64-bit imm */
+static void emit_imm(u8 rd, s64 val, struct rv_jit_context *ctx)
+{
+ /* Note that the immediate from the add is sign-extended,
+ * which means that we need to compensate this by adding 2^12,
+ * when the 12th bit is set. A simpler way of doing this, and
+ * getting rid of the check, is to just add 2**11 before the
+ * shift. The "Loading a 32-Bit constant" example from the
+ * "Computer Organization and Design, RISC-V edition" book by
+ * Patterson/Hennessy highlights this fact.
+ *
+ * This also means that we need to process LSB to MSB.
+ */
+ s64 upper = (val + (1 << 11)) >> 12;
+ /* Sign-extend lower 12 bits to 64 bits since immediates for li, addiw,
+ * and addi are signed and RVC checks will perform signed comparisons.
+ */
+ s64 lower = ((val & 0xfff) << 52) >> 52;
+ int shift;
+
+ if (is_32b_int(val)) {
+ if (upper)
+ emit_lui(rd, upper, ctx);
+
+ if (!upper) {
+ emit_li(rd, lower, ctx);
+ return;
+ }
+
+ emit_addiw(rd, rd, lower, ctx);
+ return;
+ }
+
+ shift = __ffs(upper);
+ upper >>= shift;
+ shift += 12;
+
+ emit_imm(rd, upper, ctx);
+
+ emit_slli(rd, rd, shift, ctx);
+ if (lower)
+ emit_addi(rd, rd, lower, ctx);
+}
+
+static void __build_epilogue(bool is_tail_call, struct rv_jit_context *ctx)
+{
+ int stack_adjust = ctx->stack_size, store_offset = stack_adjust - 8;
+
+ if (seen_reg(RV_REG_RA, ctx)) {
+ emit_ld(RV_REG_RA, store_offset, RV_REG_SP, ctx);
+ store_offset -= 8;
+ }
+ emit_ld(RV_REG_FP, store_offset, RV_REG_SP, ctx);
+ store_offset -= 8;
+ if (seen_reg(RV_REG_S1, ctx)) {
+ emit_ld(RV_REG_S1, store_offset, RV_REG_SP, ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S2, ctx)) {
+ emit_ld(RV_REG_S2, store_offset, RV_REG_SP, ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S3, ctx)) {
+ emit_ld(RV_REG_S3, store_offset, RV_REG_SP, ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S4, ctx)) {
+ emit_ld(RV_REG_S4, store_offset, RV_REG_SP, ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S5, ctx)) {
+ emit_ld(RV_REG_S5, store_offset, RV_REG_SP, ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S6, ctx)) {
+ emit_ld(RV_REG_S6, store_offset, RV_REG_SP, ctx);
+ store_offset -= 8;
+ }
+
+ emit_addi(RV_REG_SP, RV_REG_SP, stack_adjust, ctx);
+ /* Set return value. */
+ if (!is_tail_call)
+ emit_addiw(RV_REG_A0, RV_REG_A5, 0, ctx);
+ emit_jalr(RV_REG_ZERO, is_tail_call ? RV_REG_T3 : RV_REG_RA,
+ is_tail_call ? (RV_FENTRY_NINSNS + 1) * 4 : 0, /* skip reserved nops and TCC init */
+ ctx);
+}
+
+static void emit_bcc(u8 cond, u8 rd, u8 rs, int rvoff,
+ struct rv_jit_context *ctx)
+{
+ switch (cond) {
+ case BPF_JEQ:
+ emit(rv_beq(rd, rs, rvoff >> 1), ctx);
+ return;
+ case BPF_JGT:
+ emit(rv_bltu(rs, rd, rvoff >> 1), ctx);
+ return;
+ case BPF_JLT:
+ emit(rv_bltu(rd, rs, rvoff >> 1), ctx);
+ return;
+ case BPF_JGE:
+ emit(rv_bgeu(rd, rs, rvoff >> 1), ctx);
+ return;
+ case BPF_JLE:
+ emit(rv_bgeu(rs, rd, rvoff >> 1), ctx);
+ return;
+ case BPF_JNE:
+ emit(rv_bne(rd, rs, rvoff >> 1), ctx);
+ return;
+ case BPF_JSGT:
+ emit(rv_blt(rs, rd, rvoff >> 1), ctx);
+ return;
+ case BPF_JSLT:
+ emit(rv_blt(rd, rs, rvoff >> 1), ctx);
+ return;
+ case BPF_JSGE:
+ emit(rv_bge(rd, rs, rvoff >> 1), ctx);
+ return;
+ case BPF_JSLE:
+ emit(rv_bge(rs, rd, rvoff >> 1), ctx);
+ }
+}
+
+static void emit_branch(u8 cond, u8 rd, u8 rs, int rvoff,
+ struct rv_jit_context *ctx)
+{
+ s64 upper, lower;
+
+ if (is_13b_int(rvoff)) {
+ emit_bcc(cond, rd, rs, rvoff, ctx);
+ return;
+ }
+
+ /* Adjust for jal */
+ rvoff -= 4;
+
+ /* Transform, e.g.:
+ * bne rd,rs,foo
+ * to
+ * beq rd,rs,<.L1>
+ * (auipc foo)
+ * jal(r) foo
+ * .L1
+ */
+ cond = invert_bpf_cond(cond);
+ if (is_21b_int(rvoff)) {
+ emit_bcc(cond, rd, rs, 8, ctx);
+ emit(rv_jal(RV_REG_ZERO, rvoff >> 1), ctx);
+ return;
+ }
+
+ /* 32b No need for an additional rvoff adjustment, since we
+ * get that from the auipc at PC', where PC = PC' + 4.
+ */
+ upper = (rvoff + (1 << 11)) >> 12;
+ lower = rvoff & 0xfff;
+
+ emit_bcc(cond, rd, rs, 12, ctx);
+ emit(rv_auipc(RV_REG_T1, upper), ctx);
+ emit(rv_jalr(RV_REG_ZERO, RV_REG_T1, lower), ctx);
+}
+
+static int emit_bpf_tail_call(int insn, struct rv_jit_context *ctx)
+{
+ int tc_ninsn, off, start_insn = ctx->ninsns;
+ u8 tcc = rv_tail_call_reg(ctx);
+
+ /* a0: &ctx
+ * a1: &array
+ * a2: index
+ *
+ * if (index >= array->map.max_entries)
+ * goto out;
+ */
+ tc_ninsn = insn ? ctx->offset[insn] - ctx->offset[insn - 1] :
+ ctx->offset[0];
+ emit_zextw(RV_REG_A2, RV_REG_A2, ctx);
+
+ off = offsetof(struct bpf_array, map.max_entries);
+ if (is_12b_check(off, insn))
+ return -1;
+ emit(rv_lwu(RV_REG_T1, off, RV_REG_A1), ctx);
+ off = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn));
+ emit_branch(BPF_JGE, RV_REG_A2, RV_REG_T1, off, ctx);
+
+ /* if (--TCC < 0)
+ * goto out;
+ */
+ emit_addi(RV_REG_TCC, tcc, -1, ctx);
+ off = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn));
+ emit_branch(BPF_JSLT, RV_REG_TCC, RV_REG_ZERO, off, ctx);
+
+ /* prog = array->ptrs[index];
+ * if (!prog)
+ * goto out;
+ */
+ emit_slli(RV_REG_T2, RV_REG_A2, 3, ctx);
+ emit_add(RV_REG_T2, RV_REG_T2, RV_REG_A1, ctx);
+ off = offsetof(struct bpf_array, ptrs);
+ if (is_12b_check(off, insn))
+ return -1;
+ emit_ld(RV_REG_T2, off, RV_REG_T2, ctx);
+ off = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn));
+ emit_branch(BPF_JEQ, RV_REG_T2, RV_REG_ZERO, off, ctx);
+
+ /* goto *(prog->bpf_func + 4); */
+ off = offsetof(struct bpf_prog, bpf_func);
+ if (is_12b_check(off, insn))
+ return -1;
+ emit_ld(RV_REG_T3, off, RV_REG_T2, ctx);
+ __build_epilogue(true, ctx);
+ return 0;
+}
+
+static void init_regs(u8 *rd, u8 *rs, const struct bpf_insn *insn,
+ struct rv_jit_context *ctx)
+{
+ u8 code = insn->code;
+
+ switch (code) {
+ case BPF_JMP | BPF_JA:
+ case BPF_JMP | BPF_CALL:
+ case BPF_JMP | BPF_EXIT:
+ case BPF_JMP | BPF_TAIL_CALL:
+ break;
+ default:
+ *rd = bpf_to_rv_reg(insn->dst_reg, ctx);
+ }
+
+ if (code & (BPF_ALU | BPF_X) || code & (BPF_ALU64 | BPF_X) ||
+ code & (BPF_JMP | BPF_X) || code & (BPF_JMP32 | BPF_X) ||
+ code & BPF_LDX || code & BPF_STX)
+ *rs = bpf_to_rv_reg(insn->src_reg, ctx);
+}
+
+static int emit_jump_and_link(u8 rd, s64 rvoff, bool fixed_addr,
+ struct rv_jit_context *ctx)
+{
+ s64 upper, lower;
+
+ if (rvoff && fixed_addr && is_21b_int(rvoff)) {
+ emit(rv_jal(rd, rvoff >> 1), ctx);
+ return 0;
+ } else if (in_auipc_jalr_range(rvoff)) {
+ upper = (rvoff + (1 << 11)) >> 12;
+ lower = rvoff & 0xfff;
+ emit(rv_auipc(RV_REG_T1, upper), ctx);
+ emit(rv_jalr(rd, RV_REG_T1, lower), ctx);
+ return 0;
+ }
+
+ pr_err("bpf-jit: target offset 0x%llx is out of range\n", rvoff);
+ return -ERANGE;
+}
+
+static bool is_signed_bpf_cond(u8 cond)
+{
+ return cond == BPF_JSGT || cond == BPF_JSLT ||
+ cond == BPF_JSGE || cond == BPF_JSLE;
+}
+
+static int emit_call(u64 addr, bool fixed_addr, struct rv_jit_context *ctx)
+{
+ s64 off = 0;
+ u64 ip;
+
+ if (addr && ctx->insns && ctx->ro_insns) {
+ /*
+ * Use the ro_insns(RX) to calculate the offset as the BPF
+ * program will finally run from this memory region.
+ */
+ ip = (u64)(long)(ctx->ro_insns + ctx->ninsns);
+ off = addr - ip;
+ }
+
+ return emit_jump_and_link(RV_REG_RA, off, fixed_addr, ctx);
+}
+
+static inline void emit_kcfi(u32 hash, struct rv_jit_context *ctx)
+{
+ if (IS_ENABLED(CONFIG_CFI_CLANG))
+ emit(hash, ctx);
+}
+
+static void emit_atomic(u8 rd, u8 rs, s16 off, s32 imm, bool is64,
+ struct rv_jit_context *ctx)
+{
+ u8 r0;
+ int jmp_offset;
+
+ if (off) {
+ if (is_12b_int(off)) {
+ emit_addi(RV_REG_T1, rd, off, ctx);
+ } else {
+ emit_imm(RV_REG_T1, off, ctx);
+ emit_add(RV_REG_T1, RV_REG_T1, rd, ctx);
+ }
+ rd = RV_REG_T1;
+ }
+
+ switch (imm) {
+ /* lock *(u32/u64 *)(dst_reg + off16) <op>= src_reg */
+ case BPF_ADD:
+ emit(is64 ? rv_amoadd_d(RV_REG_ZERO, rs, rd, 0, 0) :
+ rv_amoadd_w(RV_REG_ZERO, rs, rd, 0, 0), ctx);
+ break;
+ case BPF_AND:
+ emit(is64 ? rv_amoand_d(RV_REG_ZERO, rs, rd, 0, 0) :
+ rv_amoand_w(RV_REG_ZERO, rs, rd, 0, 0), ctx);
+ break;
+ case BPF_OR:
+ emit(is64 ? rv_amoor_d(RV_REG_ZERO, rs, rd, 0, 0) :
+ rv_amoor_w(RV_REG_ZERO, rs, rd, 0, 0), ctx);
+ break;
+ case BPF_XOR:
+ emit(is64 ? rv_amoxor_d(RV_REG_ZERO, rs, rd, 0, 0) :
+ rv_amoxor_w(RV_REG_ZERO, rs, rd, 0, 0), ctx);
+ break;
+ /* src_reg = atomic_fetch_<op>(dst_reg + off16, src_reg) */
+ case BPF_ADD | BPF_FETCH:
+ emit(is64 ? rv_amoadd_d(rs, rs, rd, 0, 0) :
+ rv_amoadd_w(rs, rs, rd, 0, 0), ctx);
+ if (!is64)
+ emit_zextw(rs, rs, ctx);
+ break;
+ case BPF_AND | BPF_FETCH:
+ emit(is64 ? rv_amoand_d(rs, rs, rd, 0, 0) :
+ rv_amoand_w(rs, rs, rd, 0, 0), ctx);
+ if (!is64)
+ emit_zextw(rs, rs, ctx);
+ break;
+ case BPF_OR | BPF_FETCH:
+ emit(is64 ? rv_amoor_d(rs, rs, rd, 0, 0) :
+ rv_amoor_w(rs, rs, rd, 0, 0), ctx);
+ if (!is64)
+ emit_zextw(rs, rs, ctx);
+ break;
+ case BPF_XOR | BPF_FETCH:
+ emit(is64 ? rv_amoxor_d(rs, rs, rd, 0, 0) :
+ rv_amoxor_w(rs, rs, rd, 0, 0), ctx);
+ if (!is64)
+ emit_zextw(rs, rs, ctx);
+ break;
+ /* src_reg = atomic_xchg(dst_reg + off16, src_reg); */
+ case BPF_XCHG:
+ emit(is64 ? rv_amoswap_d(rs, rs, rd, 0, 0) :
+ rv_amoswap_w(rs, rs, rd, 0, 0), ctx);
+ if (!is64)
+ emit_zextw(rs, rs, ctx);
+ break;
+ /* r0 = atomic_cmpxchg(dst_reg + off16, r0, src_reg); */
+ case BPF_CMPXCHG:
+ r0 = bpf_to_rv_reg(BPF_REG_0, ctx);
+ emit(is64 ? rv_addi(RV_REG_T2, r0, 0) :
+ rv_addiw(RV_REG_T2, r0, 0), ctx);
+ emit(is64 ? rv_lr_d(r0, 0, rd, 0, 0) :
+ rv_lr_w(r0, 0, rd, 0, 0), ctx);
+ jmp_offset = ninsns_rvoff(8);
+ emit(rv_bne(RV_REG_T2, r0, jmp_offset >> 1), ctx);
+ emit(is64 ? rv_sc_d(RV_REG_T3, rs, rd, 0, 0) :
+ rv_sc_w(RV_REG_T3, rs, rd, 0, 0), ctx);
+ jmp_offset = ninsns_rvoff(-6);
+ emit(rv_bne(RV_REG_T3, 0, jmp_offset >> 1), ctx);
+ emit(rv_fence(0x3, 0x3), ctx);
+ break;
+ }
+}
+
+#define BPF_FIXUP_OFFSET_MASK GENMASK(26, 0)
+#define BPF_FIXUP_REG_MASK GENMASK(31, 27)
+
+bool ex_handler_bpf(const struct exception_table_entry *ex,
+ struct pt_regs *regs)
+{
+ off_t offset = FIELD_GET(BPF_FIXUP_OFFSET_MASK, ex->fixup);
+ int regs_offset = FIELD_GET(BPF_FIXUP_REG_MASK, ex->fixup);
+
+ *(unsigned long *)((void *)regs + pt_regmap[regs_offset]) = 0;
+ regs->epc = (unsigned long)&ex->fixup - offset;
+
+ return true;
+}
+
+/* For accesses to BTF pointers, add an entry to the exception table */
+static int add_exception_handler(const struct bpf_insn *insn,
+ struct rv_jit_context *ctx,
+ int dst_reg, int insn_len)
+{
+ struct exception_table_entry *ex;
+ unsigned long pc;
+ off_t ins_offset;
+ off_t fixup_offset;
+
+ if (!ctx->insns || !ctx->ro_insns || !ctx->prog->aux->extable ||
+ (BPF_MODE(insn->code) != BPF_PROBE_MEM && BPF_MODE(insn->code) != BPF_PROBE_MEMSX))
+ return 0;
+
+ if (WARN_ON_ONCE(ctx->nexentries >= ctx->prog->aux->num_exentries))
+ return -EINVAL;
+
+ if (WARN_ON_ONCE(insn_len > ctx->ninsns))
+ return -EINVAL;
+
+ if (WARN_ON_ONCE(!rvc_enabled() && insn_len == 1))
+ return -EINVAL;
+
+ ex = &ctx->prog->aux->extable[ctx->nexentries];
+ pc = (unsigned long)&ctx->ro_insns[ctx->ninsns - insn_len];
+
+ /*
+ * This is the relative offset of the instruction that may fault from
+ * the exception table itself. This will be written to the exception
+ * table and if this instruction faults, the destination register will
+ * be set to '0' and the execution will jump to the next instruction.
+ */
+ ins_offset = pc - (long)&ex->insn;
+ if (WARN_ON_ONCE(ins_offset >= 0 || ins_offset < INT_MIN))
+ return -ERANGE;
+
+ /*
+ * Since the extable follows the program, the fixup offset is always
+ * negative and limited to BPF_JIT_REGION_SIZE. Store a positive value
+ * to keep things simple, and put the destination register in the upper
+ * bits. We don't need to worry about buildtime or runtime sort
+ * modifying the upper bits because the table is already sorted, and
+ * isn't part of the main exception table.
+ *
+ * The fixup_offset is set to the next instruction from the instruction
+ * that may fault. The execution will jump to this after handling the
+ * fault.
+ */
+ fixup_offset = (long)&ex->fixup - (pc + insn_len * sizeof(u16));
+ if (!FIELD_FIT(BPF_FIXUP_OFFSET_MASK, fixup_offset))
+ return -ERANGE;
+
+ /*
+ * The offsets above have been calculated using the RO buffer but we
+ * need to use the R/W buffer for writes.
+ * switch ex to rw buffer for writing.
+ */
+ ex = (void *)ctx->insns + ((void *)ex - (void *)ctx->ro_insns);
+
+ ex->insn = ins_offset;
+
+ ex->fixup = FIELD_PREP(BPF_FIXUP_OFFSET_MASK, fixup_offset) |
+ FIELD_PREP(BPF_FIXUP_REG_MASK, dst_reg);
+ ex->type = EX_TYPE_BPF;
+
+ ctx->nexentries++;
+ return 0;
+}
+
+static int gen_jump_or_nops(void *target, void *ip, u32 *insns, bool is_call)
+{
+ s64 rvoff;
+ struct rv_jit_context ctx;
+
+ ctx.ninsns = 0;
+ ctx.insns = (u16 *)insns;
+
+ if (!target) {
+ emit(rv_nop(), &ctx);
+ emit(rv_nop(), &ctx);
+ return 0;
+ }
+
+ rvoff = (s64)(target - ip);
+ return emit_jump_and_link(is_call ? RV_REG_T0 : RV_REG_ZERO, rvoff, false, &ctx);
+}
+
+int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type poke_type,
+ void *old_addr, void *new_addr)
+{
+ u32 old_insns[RV_FENTRY_NINSNS], new_insns[RV_FENTRY_NINSNS];
+ bool is_call = poke_type == BPF_MOD_CALL;
+ int ret;
+
+ if (!is_kernel_text((unsigned long)ip) &&
+ !is_bpf_text_address((unsigned long)ip))
+ return -ENOTSUPP;
+
+ ret = gen_jump_or_nops(old_addr, ip, old_insns, is_call);
+ if (ret)
+ return ret;
+
+ if (memcmp(ip, old_insns, RV_FENTRY_NINSNS * 4))
+ return -EFAULT;
+
+ ret = gen_jump_or_nops(new_addr, ip, new_insns, is_call);
+ if (ret)
+ return ret;
+
+ cpus_read_lock();
+ mutex_lock(&text_mutex);
+ if (memcmp(ip, new_insns, RV_FENTRY_NINSNS * 4))
+ ret = patch_text(ip, new_insns, RV_FENTRY_NINSNS);
+ mutex_unlock(&text_mutex);
+ cpus_read_unlock();
+
+ return ret;
+}
+
+static void store_args(int nregs, int args_off, struct rv_jit_context *ctx)
+{
+ int i;
+
+ for (i = 0; i < nregs; i++) {
+ emit_sd(RV_REG_FP, -args_off, RV_REG_A0 + i, ctx);
+ args_off -= 8;
+ }
+}
+
+static void restore_args(int nregs, int args_off, struct rv_jit_context *ctx)
+{
+ int i;
+
+ for (i = 0; i < nregs; i++) {
+ emit_ld(RV_REG_A0 + i, -args_off, RV_REG_FP, ctx);
+ args_off -= 8;
+ }
+}
+
+static int invoke_bpf_prog(struct bpf_tramp_link *l, int args_off, int retval_off,
+ int run_ctx_off, bool save_ret, struct rv_jit_context *ctx)
+{
+ int ret, branch_off;
+ struct bpf_prog *p = l->link.prog;
+ int cookie_off = offsetof(struct bpf_tramp_run_ctx, bpf_cookie);
+
+ if (l->cookie) {
+ emit_imm(RV_REG_T1, l->cookie, ctx);
+ emit_sd(RV_REG_FP, -run_ctx_off + cookie_off, RV_REG_T1, ctx);
+ } else {
+ emit_sd(RV_REG_FP, -run_ctx_off + cookie_off, RV_REG_ZERO, ctx);
+ }
+
+ /* arg1: prog */
+ emit_imm(RV_REG_A0, (const s64)p, ctx);
+ /* arg2: &run_ctx */
+ emit_addi(RV_REG_A1, RV_REG_FP, -run_ctx_off, ctx);
+ ret = emit_call((const u64)bpf_trampoline_enter(p), true, ctx);
+ if (ret)
+ return ret;
+
+ /* if (__bpf_prog_enter(prog) == 0)
+ * goto skip_exec_of_prog;
+ */
+ branch_off = ctx->ninsns;
+ /* nop reserved for conditional jump */
+ emit(rv_nop(), ctx);
+
+ /* store prog start time */
+ emit_mv(RV_REG_S1, RV_REG_A0, ctx);
+
+ /* arg1: &args_off */
+ emit_addi(RV_REG_A0, RV_REG_FP, -args_off, ctx);
+ if (!p->jited)
+ /* arg2: progs[i]->insnsi for interpreter */
+ emit_imm(RV_REG_A1, (const s64)p->insnsi, ctx);
+ ret = emit_call((const u64)p->bpf_func, true, ctx);
+ if (ret)
+ return ret;
+
+ if (save_ret) {
+ emit_sd(RV_REG_FP, -retval_off, RV_REG_A0, ctx);
+ emit_sd(RV_REG_FP, -(retval_off - 8), regmap[BPF_REG_0], ctx);
+ }
+
+ /* update branch with beqz */
+ if (ctx->insns) {
+ int offset = ninsns_rvoff(ctx->ninsns - branch_off);
+ u32 insn = rv_beq(RV_REG_A0, RV_REG_ZERO, offset >> 1);
+ *(u32 *)(ctx->insns + branch_off) = insn;
+ }
+
+ /* arg1: prog */
+ emit_imm(RV_REG_A0, (const s64)p, ctx);
+ /* arg2: prog start time */
+ emit_mv(RV_REG_A1, RV_REG_S1, ctx);
+ /* arg3: &run_ctx */
+ emit_addi(RV_REG_A2, RV_REG_FP, -run_ctx_off, ctx);
+ ret = emit_call((const u64)bpf_trampoline_exit(p), true, ctx);
+
+ return ret;
+}
+
+static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im,
+ const struct btf_func_model *m,
+ struct bpf_tramp_links *tlinks,
+ void *func_addr, u32 flags,
+ struct rv_jit_context *ctx)
+{
+ int i, ret, offset;
+ int *branches_off = NULL;
+ int stack_size = 0, nregs = m->nr_args;
+ int retval_off, args_off, nregs_off, ip_off, run_ctx_off, sreg_off;
+ struct bpf_tramp_links *fentry = &tlinks[BPF_TRAMP_FENTRY];
+ struct bpf_tramp_links *fexit = &tlinks[BPF_TRAMP_FEXIT];
+ struct bpf_tramp_links *fmod_ret = &tlinks[BPF_TRAMP_MODIFY_RETURN];
+ bool is_struct_ops = flags & BPF_TRAMP_F_INDIRECT;
+ void *orig_call = func_addr;
+ bool save_ret;
+ u32 insn;
+
+ /* Two types of generated trampoline stack layout:
+ *
+ * 1. trampoline called from function entry
+ * --------------------------------------
+ * FP + 8 [ RA to parent func ] return address to parent
+ * function
+ * FP + 0 [ FP of parent func ] frame pointer of parent
+ * function
+ * FP - 8 [ T0 to traced func ] return address of traced
+ * function
+ * FP - 16 [ FP of traced func ] frame pointer of traced
+ * function
+ * --------------------------------------
+ *
+ * 2. trampoline called directly
+ * --------------------------------------
+ * FP - 8 [ RA to caller func ] return address to caller
+ * function
+ * FP - 16 [ FP of caller func ] frame pointer of caller
+ * function
+ * --------------------------------------
+ *
+ * FP - retval_off [ return value ] BPF_TRAMP_F_CALL_ORIG or
+ * BPF_TRAMP_F_RET_FENTRY_RET
+ * [ argN ]
+ * [ ... ]
+ * FP - args_off [ arg1 ]
+ *
+ * FP - nregs_off [ regs count ]
+ *
+ * FP - ip_off [ traced func ] BPF_TRAMP_F_IP_ARG
+ *
+ * FP - run_ctx_off [ bpf_tramp_run_ctx ]
+ *
+ * FP - sreg_off [ callee saved reg ]
+ *
+ * [ pads ] pads for 16 bytes alignment
+ */
+
+ if (flags & (BPF_TRAMP_F_ORIG_STACK | BPF_TRAMP_F_SHARE_IPMODIFY))
+ return -ENOTSUPP;
+
+ /* extra regiters for struct arguments */
+ for (i = 0; i < m->nr_args; i++)
+ if (m->arg_flags[i] & BTF_FMODEL_STRUCT_ARG)
+ nregs += round_up(m->arg_size[i], 8) / 8 - 1;
+
+ /* 8 arguments passed by registers */
+ if (nregs > 8)
+ return -ENOTSUPP;
+
+ /* room of trampoline frame to store return address and frame pointer */
+ stack_size += 16;
+
+ save_ret = flags & (BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_RET_FENTRY_RET);
+ if (save_ret) {
+ stack_size += 16; /* Save both A5 (BPF R0) and A0 */
+ retval_off = stack_size;
+ }
+
+ stack_size += nregs * 8;
+ args_off = stack_size;
+
+ stack_size += 8;
+ nregs_off = stack_size;
+
+ if (flags & BPF_TRAMP_F_IP_ARG) {
+ stack_size += 8;
+ ip_off = stack_size;
+ }
+
+ stack_size += round_up(sizeof(struct bpf_tramp_run_ctx), 8);
+ run_ctx_off = stack_size;
+
+ stack_size += 8;
+ sreg_off = stack_size;
+
+ stack_size = round_up(stack_size, 16);
+
+ if (!is_struct_ops) {
+ /* For the trampoline called from function entry,
+ * the frame of traced function and the frame of
+ * trampoline need to be considered.
+ */
+ emit_addi(RV_REG_SP, RV_REG_SP, -16, ctx);
+ emit_sd(RV_REG_SP, 8, RV_REG_RA, ctx);
+ emit_sd(RV_REG_SP, 0, RV_REG_FP, ctx);
+ emit_addi(RV_REG_FP, RV_REG_SP, 16, ctx);
+
+ emit_addi(RV_REG_SP, RV_REG_SP, -stack_size, ctx);
+ emit_sd(RV_REG_SP, stack_size - 8, RV_REG_T0, ctx);
+ emit_sd(RV_REG_SP, stack_size - 16, RV_REG_FP, ctx);
+ emit_addi(RV_REG_FP, RV_REG_SP, stack_size, ctx);
+ } else {
+ /* emit kcfi hash */
+ emit_kcfi(cfi_get_func_hash(func_addr), ctx);
+ /* For the trampoline called directly, just handle
+ * the frame of trampoline.
+ */
+ emit_addi(RV_REG_SP, RV_REG_SP, -stack_size, ctx);
+ emit_sd(RV_REG_SP, stack_size - 8, RV_REG_RA, ctx);
+ emit_sd(RV_REG_SP, stack_size - 16, RV_REG_FP, ctx);
+ emit_addi(RV_REG_FP, RV_REG_SP, stack_size, ctx);
+ }
+
+ /* callee saved register S1 to pass start time */
+ emit_sd(RV_REG_FP, -sreg_off, RV_REG_S1, ctx);
+
+ /* store ip address of the traced function */
+ if (flags & BPF_TRAMP_F_IP_ARG) {
+ emit_imm(RV_REG_T1, (const s64)func_addr, ctx);
+ emit_sd(RV_REG_FP, -ip_off, RV_REG_T1, ctx);
+ }
+
+ emit_li(RV_REG_T1, nregs, ctx);
+ emit_sd(RV_REG_FP, -nregs_off, RV_REG_T1, ctx);
+
+ store_args(nregs, args_off, ctx);
+
+ /* skip to actual body of traced function */
+ if (flags & BPF_TRAMP_F_SKIP_FRAME)
+ orig_call += RV_FENTRY_NINSNS * 4;
+
+ if (flags & BPF_TRAMP_F_CALL_ORIG) {
+ emit_imm(RV_REG_A0, (const s64)im, ctx);
+ ret = emit_call((const u64)__bpf_tramp_enter, true, ctx);
+ if (ret)
+ return ret;
+ }
+
+ for (i = 0; i < fentry->nr_links; i++) {
+ ret = invoke_bpf_prog(fentry->links[i], args_off, retval_off, run_ctx_off,
+ flags & BPF_TRAMP_F_RET_FENTRY_RET, ctx);
+ if (ret)
+ return ret;
+ }
+
+ if (fmod_ret->nr_links) {
+ branches_off = kcalloc(fmod_ret->nr_links, sizeof(int), GFP_KERNEL);
+ if (!branches_off)
+ return -ENOMEM;
+
+ /* cleanup to avoid garbage return value confusion */
+ emit_sd(RV_REG_FP, -retval_off, RV_REG_ZERO, ctx);
+ for (i = 0; i < fmod_ret->nr_links; i++) {
+ ret = invoke_bpf_prog(fmod_ret->links[i], args_off, retval_off,
+ run_ctx_off, true, ctx);
+ if (ret)
+ goto out;
+ emit_ld(RV_REG_T1, -retval_off, RV_REG_FP, ctx);
+ branches_off[i] = ctx->ninsns;
+ /* nop reserved for conditional jump */
+ emit(rv_nop(), ctx);
+ }
+ }
+
+ if (flags & BPF_TRAMP_F_CALL_ORIG) {
+ restore_args(nregs, args_off, ctx);
+ ret = emit_call((const u64)orig_call, true, ctx);
+ if (ret)
+ goto out;
+ emit_sd(RV_REG_FP, -retval_off, RV_REG_A0, ctx);
+ emit_sd(RV_REG_FP, -(retval_off - 8), regmap[BPF_REG_0], ctx);
+ im->ip_after_call = ctx->insns + ctx->ninsns;
+ /* 2 nops reserved for auipc+jalr pair */
+ emit(rv_nop(), ctx);
+ emit(rv_nop(), ctx);
+ }
+
+ /* update branches saved in invoke_bpf_mod_ret with bnez */
+ for (i = 0; ctx->insns && i < fmod_ret->nr_links; i++) {
+ offset = ninsns_rvoff(ctx->ninsns - branches_off[i]);
+ insn = rv_bne(RV_REG_T1, RV_REG_ZERO, offset >> 1);
+ *(u32 *)(ctx->insns + branches_off[i]) = insn;
+ }
+
+ for (i = 0; i < fexit->nr_links; i++) {
+ ret = invoke_bpf_prog(fexit->links[i], args_off, retval_off,
+ run_ctx_off, false, ctx);
+ if (ret)
+ goto out;
+ }
+
+ if (flags & BPF_TRAMP_F_CALL_ORIG) {
+ im->ip_epilogue = ctx->insns + ctx->ninsns;
+ emit_imm(RV_REG_A0, (const s64)im, ctx);
+ ret = emit_call((const u64)__bpf_tramp_exit, true, ctx);
+ if (ret)
+ goto out;
+ }
+
+ if (flags & BPF_TRAMP_F_RESTORE_REGS)
+ restore_args(nregs, args_off, ctx);
+
+ if (save_ret) {
+ emit_ld(RV_REG_A0, -retval_off, RV_REG_FP, ctx);
+ emit_ld(regmap[BPF_REG_0], -(retval_off - 8), RV_REG_FP, ctx);
+ }
+
+ emit_ld(RV_REG_S1, -sreg_off, RV_REG_FP, ctx);
+
+ if (!is_struct_ops) {
+ /* trampoline called from function entry */
+ emit_ld(RV_REG_T0, stack_size - 8, RV_REG_SP, ctx);
+ emit_ld(RV_REG_FP, stack_size - 16, RV_REG_SP, ctx);
+ emit_addi(RV_REG_SP, RV_REG_SP, stack_size, ctx);
+
+ emit_ld(RV_REG_RA, 8, RV_REG_SP, ctx);
+ emit_ld(RV_REG_FP, 0, RV_REG_SP, ctx);
+ emit_addi(RV_REG_SP, RV_REG_SP, 16, ctx);
+
+ if (flags & BPF_TRAMP_F_SKIP_FRAME)
+ /* return to parent function */
+ emit_jalr(RV_REG_ZERO, RV_REG_RA, 0, ctx);
+ else
+ /* return to traced function */
+ emit_jalr(RV_REG_ZERO, RV_REG_T0, 0, ctx);
+ } else {
+ /* trampoline called directly */
+ emit_ld(RV_REG_RA, stack_size - 8, RV_REG_SP, ctx);
+ emit_ld(RV_REG_FP, stack_size - 16, RV_REG_SP, ctx);
+ emit_addi(RV_REG_SP, RV_REG_SP, stack_size, ctx);
+
+ emit_jalr(RV_REG_ZERO, RV_REG_RA, 0, ctx);
+ }
+
+ ret = ctx->ninsns;
+out:
+ kfree(branches_off);
+ return ret;
+}
+
+int arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags,
+ struct bpf_tramp_links *tlinks, void *func_addr)
+{
+ struct bpf_tramp_image im;
+ struct rv_jit_context ctx;
+ int ret;
+
+ ctx.ninsns = 0;
+ ctx.insns = NULL;
+ ctx.ro_insns = NULL;
+ ret = __arch_prepare_bpf_trampoline(&im, m, tlinks, func_addr, flags, &ctx);
+
+ return ret < 0 ? ret : ninsns_rvoff(ctx.ninsns);
+}
+
+int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image,
+ void *image_end, const struct btf_func_model *m,
+ u32 flags, struct bpf_tramp_links *tlinks,
+ void *func_addr)
+{
+ int ret;
+ struct rv_jit_context ctx;
+
+ ctx.ninsns = 0;
+ /*
+ * The bpf_int_jit_compile() uses a RW buffer (ctx.insns) to write the
+ * JITed instructions and later copies it to a RX region (ctx.ro_insns).
+ * It also uses ctx.ro_insns to calculate offsets for jumps etc. As the
+ * trampoline image uses the same memory area for writing and execution,
+ * both ctx.insns and ctx.ro_insns can be set to image.
+ */
+ ctx.insns = image;
+ ctx.ro_insns = image;
+ ret = __arch_prepare_bpf_trampoline(im, m, tlinks, func_addr, flags, &ctx);
+ if (ret < 0)
+ return ret;
+
+ bpf_flush_icache(ctx.insns, ctx.insns + ctx.ninsns);
+
+ return ninsns_rvoff(ret);
+}
+
+int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx,
+ bool extra_pass)
+{
+ bool is64 = BPF_CLASS(insn->code) == BPF_ALU64 ||
+ BPF_CLASS(insn->code) == BPF_JMP;
+ int s, e, rvoff, ret, i = insn - ctx->prog->insnsi;
+ struct bpf_prog_aux *aux = ctx->prog->aux;
+ u8 rd = -1, rs = -1, code = insn->code;
+ s16 off = insn->off;
+ s32 imm = insn->imm;
+
+ init_regs(&rd, &rs, insn, ctx);
+
+ switch (code) {
+ /* dst = src */
+ case BPF_ALU | BPF_MOV | BPF_X:
+ case BPF_ALU64 | BPF_MOV | BPF_X:
+ if (imm == 1) {
+ /* Special mov32 for zext */
+ emit_zextw(rd, rd, ctx);
+ break;
+ }
+ switch (insn->off) {
+ case 0:
+ emit_mv(rd, rs, ctx);
+ break;
+ case 8:
+ emit_sextb(rd, rs, ctx);
+ break;
+ case 16:
+ emit_sexth(rd, rs, ctx);
+ break;
+ case 32:
+ emit_sextw(rd, rs, ctx);
+ break;
+ }
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+
+ /* dst = dst OP src */
+ case BPF_ALU | BPF_ADD | BPF_X:
+ case BPF_ALU64 | BPF_ADD | BPF_X:
+ emit_add(rd, rd, rs, ctx);
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_SUB | BPF_X:
+ case BPF_ALU64 | BPF_SUB | BPF_X:
+ if (is64)
+ emit_sub(rd, rd, rs, ctx);
+ else
+ emit_subw(rd, rd, rs, ctx);
+
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_AND | BPF_X:
+ case BPF_ALU64 | BPF_AND | BPF_X:
+ emit_and(rd, rd, rs, ctx);
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_OR | BPF_X:
+ case BPF_ALU64 | BPF_OR | BPF_X:
+ emit_or(rd, rd, rs, ctx);
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_XOR | BPF_X:
+ case BPF_ALU64 | BPF_XOR | BPF_X:
+ emit_xor(rd, rd, rs, ctx);
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_MUL | BPF_X:
+ case BPF_ALU64 | BPF_MUL | BPF_X:
+ emit(is64 ? rv_mul(rd, rd, rs) : rv_mulw(rd, rd, rs), ctx);
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_DIV | BPF_X:
+ case BPF_ALU64 | BPF_DIV | BPF_X:
+ if (off)
+ emit(is64 ? rv_div(rd, rd, rs) : rv_divw(rd, rd, rs), ctx);
+ else
+ emit(is64 ? rv_divu(rd, rd, rs) : rv_divuw(rd, rd, rs), ctx);
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_MOD | BPF_X:
+ case BPF_ALU64 | BPF_MOD | BPF_X:
+ if (off)
+ emit(is64 ? rv_rem(rd, rd, rs) : rv_remw(rd, rd, rs), ctx);
+ else
+ emit(is64 ? rv_remu(rd, rd, rs) : rv_remuw(rd, rd, rs), ctx);
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_LSH | BPF_X:
+ case BPF_ALU64 | BPF_LSH | BPF_X:
+ emit(is64 ? rv_sll(rd, rd, rs) : rv_sllw(rd, rd, rs), ctx);
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_RSH | BPF_X:
+ case BPF_ALU64 | BPF_RSH | BPF_X:
+ emit(is64 ? rv_srl(rd, rd, rs) : rv_srlw(rd, rd, rs), ctx);
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_ARSH | BPF_X:
+ case BPF_ALU64 | BPF_ARSH | BPF_X:
+ emit(is64 ? rv_sra(rd, rd, rs) : rv_sraw(rd, rd, rs), ctx);
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+
+ /* dst = -dst */
+ case BPF_ALU | BPF_NEG:
+ case BPF_ALU64 | BPF_NEG:
+ emit_sub(rd, RV_REG_ZERO, rd, ctx);
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+
+ /* dst = BSWAP##imm(dst) */
+ case BPF_ALU | BPF_END | BPF_FROM_LE:
+ switch (imm) {
+ case 16:
+ emit_zexth(rd, rd, ctx);
+ break;
+ case 32:
+ if (!aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case 64:
+ /* Do nothing */
+ break;
+ }
+ break;
+ case BPF_ALU | BPF_END | BPF_FROM_BE:
+ case BPF_ALU64 | BPF_END | BPF_FROM_LE:
+ emit_bswap(rd, imm, ctx);
+ break;
+
+ /* dst = imm */
+ case BPF_ALU | BPF_MOV | BPF_K:
+ case BPF_ALU64 | BPF_MOV | BPF_K:
+ emit_imm(rd, imm, ctx);
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+
+ /* dst = dst OP imm */
+ case BPF_ALU | BPF_ADD | BPF_K:
+ case BPF_ALU64 | BPF_ADD | BPF_K:
+ if (is_12b_int(imm)) {
+ emit_addi(rd, rd, imm, ctx);
+ } else {
+ emit_imm(RV_REG_T1, imm, ctx);
+ emit_add(rd, rd, RV_REG_T1, ctx);
+ }
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_SUB | BPF_K:
+ case BPF_ALU64 | BPF_SUB | BPF_K:
+ if (is_12b_int(-imm)) {
+ emit_addi(rd, rd, -imm, ctx);
+ } else {
+ emit_imm(RV_REG_T1, imm, ctx);
+ emit_sub(rd, rd, RV_REG_T1, ctx);
+ }
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_AND | BPF_K:
+ case BPF_ALU64 | BPF_AND | BPF_K:
+ if (is_12b_int(imm)) {
+ emit_andi(rd, rd, imm, ctx);
+ } else {
+ emit_imm(RV_REG_T1, imm, ctx);
+ emit_and(rd, rd, RV_REG_T1, ctx);
+ }
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_OR | BPF_K:
+ case BPF_ALU64 | BPF_OR | BPF_K:
+ if (is_12b_int(imm)) {
+ emit(rv_ori(rd, rd, imm), ctx);
+ } else {
+ emit_imm(RV_REG_T1, imm, ctx);
+ emit_or(rd, rd, RV_REG_T1, ctx);
+ }
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_XOR | BPF_K:
+ case BPF_ALU64 | BPF_XOR | BPF_K:
+ if (is_12b_int(imm)) {
+ emit(rv_xori(rd, rd, imm), ctx);
+ } else {
+ emit_imm(RV_REG_T1, imm, ctx);
+ emit_xor(rd, rd, RV_REG_T1, ctx);
+ }
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_MUL | BPF_K:
+ case BPF_ALU64 | BPF_MUL | BPF_K:
+ emit_imm(RV_REG_T1, imm, ctx);
+ emit(is64 ? rv_mul(rd, rd, RV_REG_T1) :
+ rv_mulw(rd, rd, RV_REG_T1), ctx);
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_DIV | BPF_K:
+ case BPF_ALU64 | BPF_DIV | BPF_K:
+ emit_imm(RV_REG_T1, imm, ctx);
+ if (off)
+ emit(is64 ? rv_div(rd, rd, RV_REG_T1) :
+ rv_divw(rd, rd, RV_REG_T1), ctx);
+ else
+ emit(is64 ? rv_divu(rd, rd, RV_REG_T1) :
+ rv_divuw(rd, rd, RV_REG_T1), ctx);
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_MOD | BPF_K:
+ case BPF_ALU64 | BPF_MOD | BPF_K:
+ emit_imm(RV_REG_T1, imm, ctx);
+ if (off)
+ emit(is64 ? rv_rem(rd, rd, RV_REG_T1) :
+ rv_remw(rd, rd, RV_REG_T1), ctx);
+ else
+ emit(is64 ? rv_remu(rd, rd, RV_REG_T1) :
+ rv_remuw(rd, rd, RV_REG_T1), ctx);
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_LSH | BPF_K:
+ case BPF_ALU64 | BPF_LSH | BPF_K:
+ emit_slli(rd, rd, imm, ctx);
+
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_RSH | BPF_K:
+ case BPF_ALU64 | BPF_RSH | BPF_K:
+ if (is64)
+ emit_srli(rd, rd, imm, ctx);
+ else
+ emit(rv_srliw(rd, rd, imm), ctx);
+
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+ case BPF_ALU | BPF_ARSH | BPF_K:
+ case BPF_ALU64 | BPF_ARSH | BPF_K:
+ if (is64)
+ emit_srai(rd, rd, imm, ctx);
+ else
+ emit(rv_sraiw(rd, rd, imm), ctx);
+
+ if (!is64 && !aux->verifier_zext)
+ emit_zextw(rd, rd, ctx);
+ break;
+
+ /* JUMP off */
+ case BPF_JMP | BPF_JA:
+ case BPF_JMP32 | BPF_JA:
+ if (BPF_CLASS(code) == BPF_JMP)
+ rvoff = rv_offset(i, off, ctx);
+ else
+ rvoff = rv_offset(i, imm, ctx);
+ ret = emit_jump_and_link(RV_REG_ZERO, rvoff, true, ctx);
+ if (ret)
+ return ret;
+ break;
+
+ /* IF (dst COND src) JUMP off */
+ case BPF_JMP | BPF_JEQ | BPF_X:
+ case BPF_JMP32 | BPF_JEQ | BPF_X:
+ case BPF_JMP | BPF_JGT | BPF_X:
+ case BPF_JMP32 | BPF_JGT | BPF_X:
+ case BPF_JMP | BPF_JLT | BPF_X:
+ case BPF_JMP32 | BPF_JLT | BPF_X:
+ case BPF_JMP | BPF_JGE | BPF_X:
+ case BPF_JMP32 | BPF_JGE | BPF_X:
+ case BPF_JMP | BPF_JLE | BPF_X:
+ case BPF_JMP32 | BPF_JLE | BPF_X:
+ case BPF_JMP | BPF_JNE | BPF_X:
+ case BPF_JMP32 | BPF_JNE | BPF_X:
+ case BPF_JMP | BPF_JSGT | BPF_X:
+ case BPF_JMP32 | BPF_JSGT | BPF_X:
+ case BPF_JMP | BPF_JSLT | BPF_X:
+ case BPF_JMP32 | BPF_JSLT | BPF_X:
+ case BPF_JMP | BPF_JSGE | BPF_X:
+ case BPF_JMP32 | BPF_JSGE | BPF_X:
+ case BPF_JMP | BPF_JSLE | BPF_X:
+ case BPF_JMP32 | BPF_JSLE | BPF_X:
+ case BPF_JMP | BPF_JSET | BPF_X:
+ case BPF_JMP32 | BPF_JSET | BPF_X:
+ rvoff = rv_offset(i, off, ctx);
+ if (!is64) {
+ s = ctx->ninsns;
+ if (is_signed_bpf_cond(BPF_OP(code))) {
+ emit_sextw_alt(&rs, RV_REG_T1, ctx);
+ emit_sextw_alt(&rd, RV_REG_T2, ctx);
+ } else {
+ emit_zextw_alt(&rs, RV_REG_T1, ctx);
+ emit_zextw_alt(&rd, RV_REG_T2, ctx);
+ }
+ e = ctx->ninsns;
+
+ /* Adjust for extra insns */
+ rvoff -= ninsns_rvoff(e - s);
+ }
+
+ if (BPF_OP(code) == BPF_JSET) {
+ /* Adjust for and */
+ rvoff -= 4;
+ emit_and(RV_REG_T1, rd, rs, ctx);
+ emit_branch(BPF_JNE, RV_REG_T1, RV_REG_ZERO, rvoff, ctx);
+ } else {
+ emit_branch(BPF_OP(code), rd, rs, rvoff, ctx);
+ }
+ break;
+
+ /* IF (dst COND imm) JUMP off */
+ case BPF_JMP | BPF_JEQ | BPF_K:
+ case BPF_JMP32 | BPF_JEQ | BPF_K:
+ case BPF_JMP | BPF_JGT | BPF_K:
+ case BPF_JMP32 | BPF_JGT | BPF_K:
+ case BPF_JMP | BPF_JLT | BPF_K:
+ case BPF_JMP32 | BPF_JLT | BPF_K:
+ case BPF_JMP | BPF_JGE | BPF_K:
+ case BPF_JMP32 | BPF_JGE | BPF_K:
+ case BPF_JMP | BPF_JLE | BPF_K:
+ case BPF_JMP32 | BPF_JLE | BPF_K:
+ case BPF_JMP | BPF_JNE | BPF_K:
+ case BPF_JMP32 | BPF_JNE | BPF_K:
+ case BPF_JMP | BPF_JSGT | BPF_K:
+ case BPF_JMP32 | BPF_JSGT | BPF_K:
+ case BPF_JMP | BPF_JSLT | BPF_K:
+ case BPF_JMP32 | BPF_JSLT | BPF_K:
+ case BPF_JMP | BPF_JSGE | BPF_K:
+ case BPF_JMP32 | BPF_JSGE | BPF_K:
+ case BPF_JMP | BPF_JSLE | BPF_K:
+ case BPF_JMP32 | BPF_JSLE | BPF_K:
+ rvoff = rv_offset(i, off, ctx);
+ s = ctx->ninsns;
+ if (imm)
+ emit_imm(RV_REG_T1, imm, ctx);
+ rs = imm ? RV_REG_T1 : RV_REG_ZERO;
+ if (!is64) {
+ if (is_signed_bpf_cond(BPF_OP(code))) {
+ emit_sextw_alt(&rd, RV_REG_T2, ctx);
+ /* rs has been sign extended */
+ } else {
+ emit_zextw_alt(&rd, RV_REG_T2, ctx);
+ if (imm)
+ emit_zextw(rs, rs, ctx);
+ }
+ }
+ e = ctx->ninsns;
+
+ /* Adjust for extra insns */
+ rvoff -= ninsns_rvoff(e - s);
+ emit_branch(BPF_OP(code), rd, rs, rvoff, ctx);
+ break;
+
+ case BPF_JMP | BPF_JSET | BPF_K:
+ case BPF_JMP32 | BPF_JSET | BPF_K:
+ rvoff = rv_offset(i, off, ctx);
+ s = ctx->ninsns;
+ if (is_12b_int(imm)) {
+ emit_andi(RV_REG_T1, rd, imm, ctx);
+ } else {
+ emit_imm(RV_REG_T1, imm, ctx);
+ emit_and(RV_REG_T1, rd, RV_REG_T1, ctx);
+ }
+ /* For jset32, we should clear the upper 32 bits of t1, but
+ * sign-extension is sufficient here and saves one instruction,
+ * as t1 is used only in comparison against zero.
+ */
+ if (!is64 && imm < 0)
+ emit_sextw(RV_REG_T1, RV_REG_T1, ctx);
+ e = ctx->ninsns;
+ rvoff -= ninsns_rvoff(e - s);
+ emit_branch(BPF_JNE, RV_REG_T1, RV_REG_ZERO, rvoff, ctx);
+ break;
+
+ /* function call */
+ case BPF_JMP | BPF_CALL:
+ {
+ bool fixed_addr;
+ u64 addr;
+
+ mark_call(ctx);
+ ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass,
+ &addr, &fixed_addr);
+ if (ret < 0)
+ return ret;
+
+ ret = emit_call(addr, fixed_addr, ctx);
+ if (ret)
+ return ret;
+
+ if (insn->src_reg != BPF_PSEUDO_CALL)
+ emit_mv(bpf_to_rv_reg(BPF_REG_0, ctx), RV_REG_A0, ctx);
+ break;
+ }
+ /* tail call */
+ case BPF_JMP | BPF_TAIL_CALL:
+ if (emit_bpf_tail_call(i, ctx))
+ return -1;
+ break;
+
+ /* function return */
+ case BPF_JMP | BPF_EXIT:
+ if (i == ctx->prog->len - 1)
+ break;
+
+ rvoff = epilogue_offset(ctx);
+ ret = emit_jump_and_link(RV_REG_ZERO, rvoff, true, ctx);
+ if (ret)
+ return ret;
+ break;
+
+ /* dst = imm64 */
+ case BPF_LD | BPF_IMM | BPF_DW:
+ {
+ struct bpf_insn insn1 = insn[1];
+ u64 imm64;
+
+ imm64 = (u64)insn1.imm << 32 | (u32)imm;
+ if (bpf_pseudo_func(insn)) {
+ /* fixed-length insns for extra jit pass */
+ ret = emit_addr(rd, imm64, extra_pass, ctx);
+ if (ret)
+ return ret;
+ } else {
+ emit_imm(rd, imm64, ctx);
+ }
+
+ return 1;
+ }
+
+ /* LDX: dst = *(unsigned size *)(src + off) */
+ case BPF_LDX | BPF_MEM | BPF_B:
+ case BPF_LDX | BPF_MEM | BPF_H:
+ case BPF_LDX | BPF_MEM | BPF_W:
+ case BPF_LDX | BPF_MEM | BPF_DW:
+ case BPF_LDX | BPF_PROBE_MEM | BPF_B:
+ case BPF_LDX | BPF_PROBE_MEM | BPF_H:
+ case BPF_LDX | BPF_PROBE_MEM | BPF_W:
+ case BPF_LDX | BPF_PROBE_MEM | BPF_DW:
+ /* LDSX: dst = *(signed size *)(src + off) */
+ case BPF_LDX | BPF_MEMSX | BPF_B:
+ case BPF_LDX | BPF_MEMSX | BPF_H:
+ case BPF_LDX | BPF_MEMSX | BPF_W:
+ case BPF_LDX | BPF_PROBE_MEMSX | BPF_B:
+ case BPF_LDX | BPF_PROBE_MEMSX | BPF_H:
+ case BPF_LDX | BPF_PROBE_MEMSX | BPF_W:
+ {
+ int insn_len, insns_start;
+ bool sign_ext;
+
+ sign_ext = BPF_MODE(insn->code) == BPF_MEMSX ||
+ BPF_MODE(insn->code) == BPF_PROBE_MEMSX;
+
+ switch (BPF_SIZE(code)) {
+ case BPF_B:
+ if (is_12b_int(off)) {
+ insns_start = ctx->ninsns;
+ if (sign_ext)
+ emit(rv_lb(rd, off, rs), ctx);
+ else
+ emit(rv_lbu(rd, off, rs), ctx);
+ insn_len = ctx->ninsns - insns_start;
+ break;
+ }
+
+ emit_imm(RV_REG_T1, off, ctx);
+ emit_add(RV_REG_T1, RV_REG_T1, rs, ctx);
+ insns_start = ctx->ninsns;
+ if (sign_ext)
+ emit(rv_lb(rd, 0, RV_REG_T1), ctx);
+ else
+ emit(rv_lbu(rd, 0, RV_REG_T1), ctx);
+ insn_len = ctx->ninsns - insns_start;
+ break;
+ case BPF_H:
+ if (is_12b_int(off)) {
+ insns_start = ctx->ninsns;
+ if (sign_ext)
+ emit(rv_lh(rd, off, rs), ctx);
+ else
+ emit(rv_lhu(rd, off, rs), ctx);
+ insn_len = ctx->ninsns - insns_start;
+ break;
+ }
+
+ emit_imm(RV_REG_T1, off, ctx);
+ emit_add(RV_REG_T1, RV_REG_T1, rs, ctx);
+ insns_start = ctx->ninsns;
+ if (sign_ext)
+ emit(rv_lh(rd, 0, RV_REG_T1), ctx);
+ else
+ emit(rv_lhu(rd, 0, RV_REG_T1), ctx);
+ insn_len = ctx->ninsns - insns_start;
+ break;
+ case BPF_W:
+ if (is_12b_int(off)) {
+ insns_start = ctx->ninsns;
+ if (sign_ext)
+ emit(rv_lw(rd, off, rs), ctx);
+ else
+ emit(rv_lwu(rd, off, rs), ctx);
+ insn_len = ctx->ninsns - insns_start;
+ break;
+ }
+
+ emit_imm(RV_REG_T1, off, ctx);
+ emit_add(RV_REG_T1, RV_REG_T1, rs, ctx);
+ insns_start = ctx->ninsns;
+ if (sign_ext)
+ emit(rv_lw(rd, 0, RV_REG_T1), ctx);
+ else
+ emit(rv_lwu(rd, 0, RV_REG_T1), ctx);
+ insn_len = ctx->ninsns - insns_start;
+ break;
+ case BPF_DW:
+ if (is_12b_int(off)) {
+ insns_start = ctx->ninsns;
+ emit_ld(rd, off, rs, ctx);
+ insn_len = ctx->ninsns - insns_start;
+ break;
+ }
+
+ emit_imm(RV_REG_T1, off, ctx);
+ emit_add(RV_REG_T1, RV_REG_T1, rs, ctx);
+ insns_start = ctx->ninsns;
+ emit_ld(rd, 0, RV_REG_T1, ctx);
+ insn_len = ctx->ninsns - insns_start;
+ break;
+ }
+
+ ret = add_exception_handler(insn, ctx, rd, insn_len);
+ if (ret)
+ return ret;
+
+ if (BPF_SIZE(code) != BPF_DW && insn_is_zext(&insn[1]))
+ return 1;
+ break;
+ }
+ /* speculation barrier */
+ case BPF_ST | BPF_NOSPEC:
+ break;
+
+ /* ST: *(size *)(dst + off) = imm */
+ case BPF_ST | BPF_MEM | BPF_B:
+ emit_imm(RV_REG_T1, imm, ctx);
+ if (is_12b_int(off)) {
+ emit(rv_sb(rd, off, RV_REG_T1), ctx);
+ break;
+ }
+
+ emit_imm(RV_REG_T2, off, ctx);
+ emit_add(RV_REG_T2, RV_REG_T2, rd, ctx);
+ emit(rv_sb(RV_REG_T2, 0, RV_REG_T1), ctx);
+ break;
+
+ case BPF_ST | BPF_MEM | BPF_H:
+ emit_imm(RV_REG_T1, imm, ctx);
+ if (is_12b_int(off)) {
+ emit(rv_sh(rd, off, RV_REG_T1), ctx);
+ break;
+ }
+
+ emit_imm(RV_REG_T2, off, ctx);
+ emit_add(RV_REG_T2, RV_REG_T2, rd, ctx);
+ emit(rv_sh(RV_REG_T2, 0, RV_REG_T1), ctx);
+ break;
+ case BPF_ST | BPF_MEM | BPF_W:
+ emit_imm(RV_REG_T1, imm, ctx);
+ if (is_12b_int(off)) {
+ emit_sw(rd, off, RV_REG_T1, ctx);
+ break;
+ }
+
+ emit_imm(RV_REG_T2, off, ctx);
+ emit_add(RV_REG_T2, RV_REG_T2, rd, ctx);
+ emit_sw(RV_REG_T2, 0, RV_REG_T1, ctx);
+ break;
+ case BPF_ST | BPF_MEM | BPF_DW:
+ emit_imm(RV_REG_T1, imm, ctx);
+ if (is_12b_int(off)) {
+ emit_sd(rd, off, RV_REG_T1, ctx);
+ break;
+ }
+
+ emit_imm(RV_REG_T2, off, ctx);
+ emit_add(RV_REG_T2, RV_REG_T2, rd, ctx);
+ emit_sd(RV_REG_T2, 0, RV_REG_T1, ctx);
+ break;
+
+ /* STX: *(size *)(dst + off) = src */
+ case BPF_STX | BPF_MEM | BPF_B:
+ if (is_12b_int(off)) {
+ emit(rv_sb(rd, off, rs), ctx);
+ break;
+ }
+
+ emit_imm(RV_REG_T1, off, ctx);
+ emit_add(RV_REG_T1, RV_REG_T1, rd, ctx);
+ emit(rv_sb(RV_REG_T1, 0, rs), ctx);
+ break;
+ case BPF_STX | BPF_MEM | BPF_H:
+ if (is_12b_int(off)) {
+ emit(rv_sh(rd, off, rs), ctx);
+ break;
+ }
+
+ emit_imm(RV_REG_T1, off, ctx);
+ emit_add(RV_REG_T1, RV_REG_T1, rd, ctx);
+ emit(rv_sh(RV_REG_T1, 0, rs), ctx);
+ break;
+ case BPF_STX | BPF_MEM | BPF_W:
+ if (is_12b_int(off)) {
+ emit_sw(rd, off, rs, ctx);
+ break;
+ }
+
+ emit_imm(RV_REG_T1, off, ctx);
+ emit_add(RV_REG_T1, RV_REG_T1, rd, ctx);
+ emit_sw(RV_REG_T1, 0, rs, ctx);
+ break;
+ case BPF_STX | BPF_MEM | BPF_DW:
+ if (is_12b_int(off)) {
+ emit_sd(rd, off, rs, ctx);
+ break;
+ }
+
+ emit_imm(RV_REG_T1, off, ctx);
+ emit_add(RV_REG_T1, RV_REG_T1, rd, ctx);
+ emit_sd(RV_REG_T1, 0, rs, ctx);
+ break;
+ case BPF_STX | BPF_ATOMIC | BPF_W:
+ case BPF_STX | BPF_ATOMIC | BPF_DW:
+ emit_atomic(rd, rs, off, imm,
+ BPF_SIZE(code) == BPF_DW, ctx);
+ break;
+ default:
+ pr_err("bpf-jit: unknown opcode %02x\n", code);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+void bpf_jit_build_prologue(struct rv_jit_context *ctx, bool is_subprog)
+{
+ int i, stack_adjust = 0, store_offset, bpf_stack_adjust;
+
+ bpf_stack_adjust = round_up(ctx->prog->aux->stack_depth, 16);
+ if (bpf_stack_adjust)
+ mark_fp(ctx);
+
+ if (seen_reg(RV_REG_RA, ctx))
+ stack_adjust += 8;
+ stack_adjust += 8; /* RV_REG_FP */
+ if (seen_reg(RV_REG_S1, ctx))
+ stack_adjust += 8;
+ if (seen_reg(RV_REG_S2, ctx))
+ stack_adjust += 8;
+ if (seen_reg(RV_REG_S3, ctx))
+ stack_adjust += 8;
+ if (seen_reg(RV_REG_S4, ctx))
+ stack_adjust += 8;
+ if (seen_reg(RV_REG_S5, ctx))
+ stack_adjust += 8;
+ if (seen_reg(RV_REG_S6, ctx))
+ stack_adjust += 8;
+
+ stack_adjust = round_up(stack_adjust, 16);
+ stack_adjust += bpf_stack_adjust;
+
+ store_offset = stack_adjust - 8;
+
+ /* emit kcfi type preamble immediately before the first insn */
+ emit_kcfi(is_subprog ? cfi_bpf_subprog_hash : cfi_bpf_hash, ctx);
+
+ /* nops reserved for auipc+jalr pair */
+ for (i = 0; i < RV_FENTRY_NINSNS; i++)
+ emit(rv_nop(), ctx);
+
+ /* First instruction is always setting the tail-call-counter
+ * (TCC) register. This instruction is skipped for tail calls.
+ * Force using a 4-byte (non-compressed) instruction.
+ */
+ emit(rv_addi(RV_REG_TCC, RV_REG_ZERO, MAX_TAIL_CALL_CNT), ctx);
+
+ emit_addi(RV_REG_SP, RV_REG_SP, -stack_adjust, ctx);
+
+ if (seen_reg(RV_REG_RA, ctx)) {
+ emit_sd(RV_REG_SP, store_offset, RV_REG_RA, ctx);
+ store_offset -= 8;
+ }
+ emit_sd(RV_REG_SP, store_offset, RV_REG_FP, ctx);
+ store_offset -= 8;
+ if (seen_reg(RV_REG_S1, ctx)) {
+ emit_sd(RV_REG_SP, store_offset, RV_REG_S1, ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S2, ctx)) {
+ emit_sd(RV_REG_SP, store_offset, RV_REG_S2, ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S3, ctx)) {
+ emit_sd(RV_REG_SP, store_offset, RV_REG_S3, ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S4, ctx)) {
+ emit_sd(RV_REG_SP, store_offset, RV_REG_S4, ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S5, ctx)) {
+ emit_sd(RV_REG_SP, store_offset, RV_REG_S5, ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S6, ctx)) {
+ emit_sd(RV_REG_SP, store_offset, RV_REG_S6, ctx);
+ store_offset -= 8;
+ }
+
+ emit_addi(RV_REG_FP, RV_REG_SP, stack_adjust, ctx);
+
+ if (bpf_stack_adjust)
+ emit_addi(RV_REG_S5, RV_REG_SP, bpf_stack_adjust, ctx);
+
+ /* Program contains calls and tail calls, so RV_REG_TCC need
+ * to be saved across calls.
+ */
+ if (seen_tail_call(ctx) && seen_call(ctx))
+ emit_mv(RV_REG_TCC_SAVED, RV_REG_TCC, ctx);
+
+ ctx->stack_size = stack_adjust;
+}
+
+void bpf_jit_build_epilogue(struct rv_jit_context *ctx)
+{
+ __build_epilogue(false, ctx);
+}
+
+bool bpf_jit_supports_kfunc_call(void)
+{
+ return true;
+}
+
+bool bpf_jit_supports_ptr_xchg(void)
+{
+ return true;
+}