diff options
Diffstat (limited to 'arch/riscv/net/bpf_jit_comp64.c')
| -rw-r--r-- | arch/riscv/net/bpf_jit_comp64.c | 279 |
1 files changed, 264 insertions, 15 deletions
diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c index 1adf2f39ce59cb..79a001d5533ea6 100644 --- a/arch/riscv/net/bpf_jit_comp64.c +++ b/arch/riscv/net/bpf_jit_comp64.c @@ -12,12 +12,14 @@ #include <linux/stop_machine.h> #include <asm/patch.h> #include <asm/cfi.h> +#include <asm/percpu.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 */ +#define RV_REG_ARENA RV_REG_S7 /* For storing arena_vm_start */ static const int regmap[] = { [BPF_REG_0] = RV_REG_A5, @@ -255,6 +257,10 @@ static void __build_epilogue(bool is_tail_call, struct rv_jit_context *ctx) emit_ld(RV_REG_S6, store_offset, RV_REG_SP, ctx); store_offset -= 8; } + if (ctx->arena_vm_start) { + emit_ld(RV_REG_ARENA, store_offset, RV_REG_SP, ctx); + store_offset -= 8; + } emit_addi(RV_REG_SP, RV_REG_SP, stack_adjust, ctx); /* Set return value. */ @@ -498,33 +504,33 @@ static void emit_atomic(u8 rd, u8 rs, s16 off, s32 imm, bool is64, 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); + emit(is64 ? rv_amoadd_d(rs, rs, rd, 1, 1) : + rv_amoadd_w(rs, rs, rd, 1, 1), 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); + emit(is64 ? rv_amoand_d(rs, rs, rd, 1, 1) : + rv_amoand_w(rs, rs, rd, 1, 1), 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); + emit(is64 ? rv_amoor_d(rs, rs, rd, 1, 1) : + rv_amoor_w(rs, rs, rd, 1, 1), 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); + emit(is64 ? rv_amoxor_d(rs, rs, rd, 1, 1) : + rv_amoxor_w(rs, rs, rd, 1, 1), 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); + emit(is64 ? rv_amoswap_d(rs, rs, rd, 1, 1) : + rv_amoswap_w(rs, rs, rd, 1, 1), ctx); if (!is64) emit_zextw(rs, rs, ctx); break; @@ -548,6 +554,7 @@ static void emit_atomic(u8 rd, u8 rs, s16 off, s32 imm, bool is64, #define BPF_FIXUP_OFFSET_MASK GENMASK(26, 0) #define BPF_FIXUP_REG_MASK GENMASK(31, 27) +#define REG_DONT_CLEAR_MARKER 0 /* RV_REG_ZERO unused in pt_regmap */ bool ex_handler_bpf(const struct exception_table_entry *ex, struct pt_regs *regs) @@ -555,7 +562,8 @@ bool ex_handler_bpf(const struct exception_table_entry *ex, 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; + if (regs_offset != REG_DONT_CLEAR_MARKER) + *(unsigned long *)((void *)regs + pt_regmap[regs_offset]) = 0; regs->epc = (unsigned long)&ex->fixup - offset; return true; @@ -572,7 +580,8 @@ static int add_exception_handler(const struct bpf_insn *insn, 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)) + (BPF_MODE(insn->code) != BPF_PROBE_MEM && BPF_MODE(insn->code) != BPF_PROBE_MEMSX && + BPF_MODE(insn->code) != BPF_PROBE_MEM32)) return 0; if (WARN_ON_ONCE(ctx->nexentries >= ctx->prog->aux->num_exentries)) @@ -722,6 +731,9 @@ static int invoke_bpf_prog(struct bpf_tramp_link *l, int args_off, int retval_of if (ret) return ret; + /* store prog start time */ + emit_mv(RV_REG_S1, RV_REG_A0, ctx); + /* if (__bpf_prog_enter(prog) == 0) * goto skip_exec_of_prog; */ @@ -729,9 +741,6 @@ static int invoke_bpf_prog(struct bpf_tramp_link *l, int args_off, int retval_of /* 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) @@ -1073,6 +1082,33 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, /* dst = src */ case BPF_ALU | BPF_MOV | BPF_X: case BPF_ALU64 | BPF_MOV | BPF_X: + if (insn_is_cast_user(insn)) { + emit_mv(RV_REG_T1, rs, ctx); + emit_zextw(RV_REG_T1, RV_REG_T1, ctx); + emit_imm(rd, (ctx->user_vm_start >> 32) << 32, ctx); + emit(rv_beq(RV_REG_T1, RV_REG_ZERO, 4), ctx); + emit_or(RV_REG_T1, rd, RV_REG_T1, ctx); + emit_mv(rd, RV_REG_T1, ctx); + break; + } else if (insn_is_mov_percpu_addr(insn)) { + if (rd != rs) + emit_mv(rd, rs, ctx); +#ifdef CONFIG_SMP + /* Load current CPU number in T1 */ + emit_ld(RV_REG_T1, offsetof(struct thread_info, cpu), + RV_REG_TP, ctx); + /* << 3 because offsets are 8 bytes */ + emit_slli(RV_REG_T1, RV_REG_T1, 3, ctx); + /* Load address of __per_cpu_offset array in T2 */ + emit_addr(RV_REG_T2, (u64)&__per_cpu_offset, extra_pass, ctx); + /* Add offset of current CPU to __per_cpu_offset */ + emit_add(RV_REG_T1, RV_REG_T2, RV_REG_T1, ctx); + /* Load __per_cpu_offset[cpu] in T1 */ + emit_ld(RV_REG_T1, 0, RV_REG_T1, ctx); + /* Add the offset to Rd */ + emit_add(rd, rd, RV_REG_T1, ctx); +#endif + } if (imm == 1) { /* Special mov32 for zext */ emit_zextw(rd, rd, ctx); @@ -1457,6 +1493,22 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, bool fixed_addr; u64 addr; + /* Inline calls to bpf_get_smp_processor_id() + * + * RV_REG_TP holds the address of the current CPU's task_struct and thread_info is + * at offset 0 in task_struct. + * Load cpu from thread_info: + * Set R0 to ((struct thread_info *)(RV_REG_TP))->cpu + * + * This replicates the implementation of raw_smp_processor_id() on RISCV + */ + if (insn->src_reg == 0 && insn->imm == BPF_FUNC_get_smp_processor_id) { + /* Load current CPU number in R0 */ + emit_ld(bpf_to_rv_reg(BPF_REG_0, ctx), offsetof(struct thread_info, cpu), + RV_REG_TP, ctx); + break; + } + mark_call(ctx); ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass, &addr, &fixed_addr); @@ -1539,6 +1591,11 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, case BPF_LDX | BPF_PROBE_MEMSX | BPF_B: case BPF_LDX | BPF_PROBE_MEMSX | BPF_H: case BPF_LDX | BPF_PROBE_MEMSX | BPF_W: + /* LDX | PROBE_MEM32: dst = *(unsigned size *)(src + RV_REG_ARENA + off) */ + case BPF_LDX | BPF_PROBE_MEM32 | BPF_B: + case BPF_LDX | BPF_PROBE_MEM32 | BPF_H: + case BPF_LDX | BPF_PROBE_MEM32 | BPF_W: + case BPF_LDX | BPF_PROBE_MEM32 | BPF_DW: { int insn_len, insns_start; bool sign_ext; @@ -1546,6 +1603,11 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, sign_ext = BPF_MODE(insn->code) == BPF_MEMSX || BPF_MODE(insn->code) == BPF_PROBE_MEMSX; + if (BPF_MODE(insn->code) == BPF_PROBE_MEM32) { + emit_add(RV_REG_T2, rs, RV_REG_ARENA, ctx); + rs = RV_REG_T2; + } + switch (BPF_SIZE(code)) { case BPF_B: if (is_12b_int(off)) { @@ -1682,6 +1744,86 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, emit_sd(RV_REG_T2, 0, RV_REG_T1, ctx); break; + case BPF_ST | BPF_PROBE_MEM32 | BPF_B: + case BPF_ST | BPF_PROBE_MEM32 | BPF_H: + case BPF_ST | BPF_PROBE_MEM32 | BPF_W: + case BPF_ST | BPF_PROBE_MEM32 | BPF_DW: + { + int insn_len, insns_start; + + emit_add(RV_REG_T3, rd, RV_REG_ARENA, ctx); + rd = RV_REG_T3; + + /* Load imm to a register then store it */ + emit_imm(RV_REG_T1, imm, ctx); + + switch (BPF_SIZE(code)) { + case BPF_B: + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + emit(rv_sb(rd, off, RV_REG_T1), ctx); + insn_len = ctx->ninsns - insns_start; + break; + } + + emit_imm(RV_REG_T2, off, ctx); + emit_add(RV_REG_T2, RV_REG_T2, rd, ctx); + insns_start = ctx->ninsns; + emit(rv_sb(RV_REG_T2, 0, RV_REG_T1), ctx); + insn_len = ctx->ninsns - insns_start; + break; + case BPF_H: + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + emit(rv_sh(rd, off, RV_REG_T1), ctx); + insn_len = ctx->ninsns - insns_start; + break; + } + + emit_imm(RV_REG_T2, off, ctx); + emit_add(RV_REG_T2, RV_REG_T2, rd, ctx); + insns_start = ctx->ninsns; + emit(rv_sh(RV_REG_T2, 0, RV_REG_T1), ctx); + insn_len = ctx->ninsns - insns_start; + break; + case BPF_W: + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + emit_sw(rd, off, RV_REG_T1, ctx); + insn_len = ctx->ninsns - insns_start; + break; + } + + emit_imm(RV_REG_T2, off, ctx); + emit_add(RV_REG_T2, RV_REG_T2, rd, ctx); + insns_start = ctx->ninsns; + emit_sw(RV_REG_T2, 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_sd(rd, off, RV_REG_T1, ctx); + insn_len = ctx->ninsns - insns_start; + break; + } + + emit_imm(RV_REG_T2, off, ctx); + emit_add(RV_REG_T2, RV_REG_T2, rd, ctx); + insns_start = ctx->ninsns; + emit_sd(RV_REG_T2, 0, RV_REG_T1, ctx); + insn_len = ctx->ninsns - insns_start; + break; + } + + ret = add_exception_handler(insn, ctx, REG_DONT_CLEAR_MARKER, + insn_len); + if (ret) + return ret; + + break; + } + /* STX: *(size *)(dst + off) = src */ case BPF_STX | BPF_MEM | BPF_B: if (is_12b_int(off)) { @@ -1728,6 +1870,84 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, emit_atomic(rd, rs, off, imm, BPF_SIZE(code) == BPF_DW, ctx); break; + + case BPF_STX | BPF_PROBE_MEM32 | BPF_B: + case BPF_STX | BPF_PROBE_MEM32 | BPF_H: + case BPF_STX | BPF_PROBE_MEM32 | BPF_W: + case BPF_STX | BPF_PROBE_MEM32 | BPF_DW: + { + int insn_len, insns_start; + + emit_add(RV_REG_T2, rd, RV_REG_ARENA, ctx); + rd = RV_REG_T2; + + switch (BPF_SIZE(code)) { + case BPF_B: + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + emit(rv_sb(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, rd, ctx); + insns_start = ctx->ninsns; + emit(rv_sb(RV_REG_T1, 0, rs), ctx); + insn_len = ctx->ninsns - insns_start; + break; + case BPF_H: + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + emit(rv_sh(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, rd, ctx); + insns_start = ctx->ninsns; + emit(rv_sh(RV_REG_T1, 0, rs), ctx); + insn_len = ctx->ninsns - insns_start; + break; + case BPF_W: + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + emit_sw(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, rd, ctx); + insns_start = ctx->ninsns; + emit_sw(RV_REG_T1, 0, rs, ctx); + insn_len = ctx->ninsns - insns_start; + break; + case BPF_DW: + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + emit_sd(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, rd, ctx); + insns_start = ctx->ninsns; + emit_sd(RV_REG_T1, 0, rs, ctx); + insn_len = ctx->ninsns - insns_start; + break; + } + + ret = add_exception_handler(insn, ctx, REG_DONT_CLEAR_MARKER, + insn_len); + if (ret) + return ret; + + break; + } + default: pr_err("bpf-jit: unknown opcode %02x\n", code); return -EINVAL; @@ -1759,6 +1979,8 @@ void bpf_jit_build_prologue(struct rv_jit_context *ctx, bool is_subprog) stack_adjust += 8; if (seen_reg(RV_REG_S6, ctx)) stack_adjust += 8; + if (ctx->arena_vm_start) + stack_adjust += 8; stack_adjust = round_up(stack_adjust, 16); stack_adjust += bpf_stack_adjust; @@ -1810,6 +2032,10 @@ void bpf_jit_build_prologue(struct rv_jit_context *ctx, bool is_subprog) emit_sd(RV_REG_SP, store_offset, RV_REG_S6, ctx); store_offset -= 8; } + if (ctx->arena_vm_start) { + emit_sd(RV_REG_SP, store_offset, RV_REG_ARENA, ctx); + store_offset -= 8; + } emit_addi(RV_REG_FP, RV_REG_SP, stack_adjust, ctx); @@ -1823,6 +2049,9 @@ void bpf_jit_build_prologue(struct rv_jit_context *ctx, bool is_subprog) emit_mv(RV_REG_TCC_SAVED, RV_REG_TCC, ctx); ctx->stack_size = stack_adjust; + + if (ctx->arena_vm_start) + emit_imm(RV_REG_ARENA, ctx->arena_vm_start, ctx); } void bpf_jit_build_epilogue(struct rv_jit_context *ctx) @@ -1839,3 +2068,23 @@ bool bpf_jit_supports_ptr_xchg(void) { return true; } + +bool bpf_jit_supports_arena(void) +{ + return true; +} + +bool bpf_jit_supports_percpu_insn(void) +{ + return true; +} + +bool bpf_jit_inlines_helper_call(s32 imm) +{ + switch (imm) { + case BPF_FUNC_get_smp_processor_id: + return true; + default: + return false; + } +} |