diff options
Diffstat (limited to 'arch/loongarch/net/bpf_jit.c')
| -rw-r--r-- | arch/loongarch/net/bpf_jit.c | 709 |
1 files changed, 644 insertions, 65 deletions
diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c index ea357a3edc09..abfdb6bb5c38 100644 --- a/arch/loongarch/net/bpf_jit.c +++ b/arch/loongarch/net/bpf_jit.c @@ -4,13 +4,20 @@ * * Copyright (C) 2022 Loongson Technology Corporation Limited */ +#include <linux/memory.h> #include "bpf_jit.h" -#define REG_TCC LOONGARCH_GPR_A6 -#define TCC_SAVED LOONGARCH_GPR_S5 +#define LOONGARCH_MAX_REG_ARGS 8 + +#define LOONGARCH_LONG_JUMP_NINSNS 5 +#define LOONGARCH_LONG_JUMP_NBYTES (LOONGARCH_LONG_JUMP_NINSNS * 4) -#define SAVE_RA BIT(0) -#define SAVE_TCC BIT(1) +#define LOONGARCH_FENTRY_NINSNS 2 +#define LOONGARCH_FENTRY_NBYTES (LOONGARCH_FENTRY_NINSNS * 4) +#define LOONGARCH_BPF_FENTRY_NBYTES (LOONGARCH_LONG_JUMP_NINSNS * 4) + +#define REG_TCC LOONGARCH_GPR_A6 +#define BPF_TAIL_CALL_CNT_PTR_STACK_OFF(stack) (round_up(stack, 16) - 80) static const int regmap[] = { /* return value from in-kernel function, and exit value for eBPF program */ @@ -32,32 +39,57 @@ static const int regmap[] = { [BPF_REG_AX] = LOONGARCH_GPR_T0, }; -static void mark_call(struct jit_ctx *ctx) +static void prepare_bpf_tail_call_cnt(struct jit_ctx *ctx, int *store_offset) { - ctx->flags |= SAVE_RA; -} + const struct bpf_prog *prog = ctx->prog; + const bool is_main_prog = !bpf_is_subprog(prog); -static void mark_tail_call(struct jit_ctx *ctx) -{ - ctx->flags |= SAVE_TCC; -} + if (is_main_prog) { + /* + * LOONGARCH_GPR_T3 = MAX_TAIL_CALL_CNT + * if (REG_TCC > T3 ) + * std REG_TCC -> LOONGARCH_GPR_SP + store_offset + * else + * std REG_TCC -> LOONGARCH_GPR_SP + store_offset + * REG_TCC = LOONGARCH_GPR_SP + store_offset + * + * std REG_TCC -> LOONGARCH_GPR_SP + store_offset + * + * The purpose of this code is to first push the TCC into stack, + * and then push the address of TCC into stack. + * In cases where bpf2bpf and tailcall are used in combination, + * the value in REG_TCC may be a count or an address, + * these two cases need to be judged and handled separately. + */ + emit_insn(ctx, addid, LOONGARCH_GPR_T3, LOONGARCH_GPR_ZERO, MAX_TAIL_CALL_CNT); + *store_offset -= sizeof(long); -static bool seen_call(struct jit_ctx *ctx) -{ - return (ctx->flags & SAVE_RA); -} + emit_cond_jmp(ctx, BPF_JGT, REG_TCC, LOONGARCH_GPR_T3, 4); -static bool seen_tail_call(struct jit_ctx *ctx) -{ - return (ctx->flags & SAVE_TCC); -} + /* + * If REG_TCC < MAX_TAIL_CALL_CNT, the value in REG_TCC is a count, + * push tcc into stack + */ + emit_insn(ctx, std, REG_TCC, LOONGARCH_GPR_SP, *store_offset); -static u8 tail_call_reg(struct jit_ctx *ctx) -{ - if (seen_call(ctx)) - return TCC_SAVED; + /* Push the address of TCC into the REG_TCC */ + emit_insn(ctx, addid, REG_TCC, LOONGARCH_GPR_SP, *store_offset); + + emit_uncond_jmp(ctx, 2); + + /* + * If REG_TCC > MAX_TAIL_CALL_CNT, the value in REG_TCC is an address, + * push tcc_ptr into stack + */ + emit_insn(ctx, std, REG_TCC, LOONGARCH_GPR_SP, *store_offset); + } else { + *store_offset -= sizeof(long); + emit_insn(ctx, std, REG_TCC, LOONGARCH_GPR_SP, *store_offset); + } - return REG_TCC; + /* Push tcc_ptr into stack */ + *store_offset -= sizeof(long); + emit_insn(ctx, std, REG_TCC, LOONGARCH_GPR_SP, *store_offset); } /* @@ -80,6 +112,10 @@ static u8 tail_call_reg(struct jit_ctx *ctx) * | $s4 | * +-------------------------+ * | $s5 | + * +-------------------------+ + * | tcc | + * +-------------------------+ + * | tcc_ptr | * +-------------------------+ <--BPF_REG_FP * | prog->aux->stack_depth | * | (optional) | @@ -88,22 +124,32 @@ static u8 tail_call_reg(struct jit_ctx *ctx) */ static void build_prologue(struct jit_ctx *ctx) { - int stack_adjust = 0, store_offset, bpf_stack_adjust; + int i, stack_adjust = 0, store_offset, bpf_stack_adjust; + const struct bpf_prog *prog = ctx->prog; + const bool is_main_prog = !bpf_is_subprog(prog); bpf_stack_adjust = round_up(ctx->prog->aux->stack_depth, 16); - /* To store ra, fp, s0, s1, s2, s3, s4 and s5. */ + /* To store ra, fp, s0, s1, s2, s3, s4, s5 */ stack_adjust += sizeof(long) * 8; + /* To store tcc and tcc_ptr */ + stack_adjust += sizeof(long) * 2; + stack_adjust = round_up(stack_adjust, 16); stack_adjust += bpf_stack_adjust; + /* Reserve space for the move_imm + jirl instruction */ + for (i = 0; i < LOONGARCH_LONG_JUMP_NINSNS; i++) + emit_insn(ctx, nop); + /* - * First instruction initializes the tail call count (TCC). - * On tail call we skip this instruction, and the TCC is - * passed in REG_TCC from the caller. + * First instruction initializes the tail call count (TCC) + * register to zero. On tail call we skip this instruction, + * and the TCC is passed in REG_TCC from the caller. */ - emit_insn(ctx, addid, REG_TCC, LOONGARCH_GPR_ZERO, MAX_TAIL_CALL_CNT); + if (is_main_prog) + emit_insn(ctx, addid, REG_TCC, LOONGARCH_GPR_ZERO, 0); emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, -stack_adjust); @@ -131,18 +177,13 @@ static void build_prologue(struct jit_ctx *ctx) store_offset -= sizeof(long); emit_insn(ctx, std, LOONGARCH_GPR_S5, LOONGARCH_GPR_SP, store_offset); + prepare_bpf_tail_call_cnt(ctx, &store_offset); + emit_insn(ctx, addid, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_adjust); if (bpf_stack_adjust) emit_insn(ctx, addid, regmap[BPF_REG_FP], LOONGARCH_GPR_SP, bpf_stack_adjust); - /* - * Program contains calls and tail calls, so REG_TCC need - * to be saved across calls. - */ - if (seen_tail_call(ctx) && seen_call(ctx)) - move_reg(ctx, TCC_SAVED, REG_TCC); - ctx->stack_size = stack_adjust; } @@ -175,6 +216,16 @@ static void __build_epilogue(struct jit_ctx *ctx, bool is_tail_call) load_offset -= sizeof(long); emit_insn(ctx, ldd, LOONGARCH_GPR_S5, LOONGARCH_GPR_SP, load_offset); + /* + * When push into the stack, follow the order of tcc then tcc_ptr. + * When pop from the stack, first pop tcc_ptr then followed by tcc. + */ + load_offset -= 2 * sizeof(long); + emit_insn(ctx, ldd, REG_TCC, LOONGARCH_GPR_SP, load_offset); + + load_offset += sizeof(long); + emit_insn(ctx, ldd, REG_TCC, LOONGARCH_GPR_SP, load_offset); + emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, stack_adjust); if (!is_tail_call) { @@ -187,7 +238,7 @@ static void __build_epilogue(struct jit_ctx *ctx, bool is_tail_call) * Call the next bpf prog and skip the first instruction * of TCC initialization. */ - emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_T3, 1); + emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_T3, 6); } } @@ -206,12 +257,10 @@ bool bpf_jit_supports_far_kfunc_call(void) return true; } -/* initialized on the first pass of build_body() */ -static int out_offset = -1; -static int emit_bpf_tail_call(struct jit_ctx *ctx) +static int emit_bpf_tail_call(struct jit_ctx *ctx, int insn) { - int off; - u8 tcc = tail_call_reg(ctx); + int off, tc_ninsn = 0; + int tcc_ptr_off = BPF_TAIL_CALL_CNT_PTR_STACK_OFF(ctx->stack_size); u8 a1 = LOONGARCH_GPR_A1; u8 a2 = LOONGARCH_GPR_A2; u8 t1 = LOONGARCH_GPR_T1; @@ -220,7 +269,7 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx) const int idx0 = ctx->idx; #define cur_offset (ctx->idx - idx0) -#define jmp_offset (out_offset - (cur_offset)) +#define jmp_offset (tc_ninsn - (cur_offset)) /* * a0: &ctx @@ -230,6 +279,7 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx) * if (index >= array->map.max_entries) * goto out; */ + tc_ninsn = insn ? ctx->offset[insn+1] - ctx->offset[insn] : ctx->offset[0]; off = offsetof(struct bpf_array, map.max_entries); emit_insn(ctx, ldwu, t1, a1, off); /* bgeu $a2, $t1, jmp_offset */ @@ -237,11 +287,15 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx) goto toofar; /* - * if (--TCC < 0) - * goto out; + * if ((*tcc_ptr)++ >= MAX_TAIL_CALL_CNT) + * goto out; */ - emit_insn(ctx, addid, REG_TCC, tcc, -1); - if (emit_tailcall_jmp(ctx, BPF_JSLT, REG_TCC, LOONGARCH_GPR_ZERO, jmp_offset) < 0) + emit_insn(ctx, ldd, REG_TCC, LOONGARCH_GPR_SP, tcc_ptr_off); + emit_insn(ctx, ldd, t3, REG_TCC, 0); + emit_insn(ctx, addid, t3, t3, 1); + emit_insn(ctx, std, t3, REG_TCC, 0); + emit_insn(ctx, addid, t2, LOONGARCH_GPR_ZERO, MAX_TAIL_CALL_CNT); + if (emit_tailcall_jmp(ctx, BPF_JSGT, t3, t2, jmp_offset) < 0) goto toofar; /* @@ -261,15 +315,6 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx) emit_insn(ctx, ldd, t3, t2, off); __build_epilogue(ctx, true); - /* out: */ - if (out_offset == -1) - out_offset = cur_offset; - if (cur_offset != out_offset) { - pr_err_once("tail_call out_offset = %d, expected %d!\n", - cur_offset, out_offset); - return -1; - } - return 0; toofar: @@ -461,7 +506,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext u64 func_addr; bool func_addr_fixed, sign_extend; int i = insn - ctx->prog->insnsi; - int ret, jmp_offset; + int ret, jmp_offset, tcc_ptr_off; const u8 code = insn->code; const u8 cond = BPF_OP(code); const u8 t1 = LOONGARCH_GPR_T1; @@ -897,21 +942,27 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext /* function call */ case BPF_JMP | BPF_CALL: - mark_call(ctx); ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass, &func_addr, &func_addr_fixed); if (ret < 0) return ret; + if (insn->src_reg == BPF_PSEUDO_CALL) { + tcc_ptr_off = BPF_TAIL_CALL_CNT_PTR_STACK_OFF(ctx->stack_size); + emit_insn(ctx, ldd, REG_TCC, LOONGARCH_GPR_SP, tcc_ptr_off); + } + move_addr(ctx, t1, func_addr); emit_insn(ctx, jirl, LOONGARCH_GPR_RA, t1, 0); - move_reg(ctx, regmap[BPF_REG_0], LOONGARCH_GPR_A0); + + if (insn->src_reg != BPF_PSEUDO_CALL) + move_reg(ctx, regmap[BPF_REG_0], LOONGARCH_GPR_A0); + break; /* tail call */ case BPF_JMP | BPF_TAIL_CALL: - mark_tail_call(ctx); - if (emit_bpf_tail_call(ctx) < 0) + if (emit_bpf_tail_call(ctx, i) < 0) return -EINVAL; break; @@ -930,7 +981,10 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext { const u64 imm64 = (u64)(insn + 1)->imm << 32 | (u32)insn->imm; - move_imm(ctx, dst, imm64, is32); + if (bpf_pseudo_func(insn)) + move_addr(ctx, dst, imm64); + else + move_imm(ctx, dst, imm64, is32); return 1; } @@ -1172,12 +1226,528 @@ static int validate_code(struct jit_ctx *ctx) return -1; } + return 0; +} + +static int validate_ctx(struct jit_ctx *ctx) +{ + if (validate_code(ctx)) + return -1; + if (WARN_ON_ONCE(ctx->num_exentries != ctx->prog->aux->num_exentries)) return -1; return 0; } +static int emit_jump_and_link(struct jit_ctx *ctx, u8 rd, u64 target) +{ + if (!target) { + pr_err("bpf_jit: jump target address is error\n"); + return -EFAULT; + } + + move_imm(ctx, LOONGARCH_GPR_T1, target, false); + emit_insn(ctx, jirl, rd, LOONGARCH_GPR_T1, 0); + + return 0; +} + +static int emit_jump_or_nops(void *target, void *ip, u32 *insns, bool is_call) +{ + int i; + struct jit_ctx ctx; + + ctx.idx = 0; + ctx.image = (union loongarch_instruction *)insns; + + if (!target) { + for (i = 0; i < LOONGARCH_LONG_JUMP_NINSNS; i++) + emit_insn((&ctx), nop); + return 0; + } + + return emit_jump_and_link(&ctx, is_call ? LOONGARCH_GPR_T0 : LOONGARCH_GPR_ZERO, (u64)target); +} + +static int emit_call(struct jit_ctx *ctx, u64 addr) +{ + return emit_jump_and_link(ctx, LOONGARCH_GPR_RA, addr); +} + +void *bpf_arch_text_copy(void *dst, void *src, size_t len) +{ + int ret; + + mutex_lock(&text_mutex); + ret = larch_insn_text_copy(dst, src, len); + mutex_unlock(&text_mutex); + + return ret ? ERR_PTR(-EINVAL) : dst; +} + +int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type poke_type, + void *old_addr, void *new_addr) +{ + int ret; + bool is_call = (poke_type == BPF_MOD_CALL); + u32 old_insns[LOONGARCH_LONG_JUMP_NINSNS] = {[0 ... 4] = INSN_NOP}; + u32 new_insns[LOONGARCH_LONG_JUMP_NINSNS] = {[0 ... 4] = INSN_NOP}; + + if (!is_kernel_text((unsigned long)ip) && + !is_bpf_text_address((unsigned long)ip)) + return -ENOTSUPP; + + ret = emit_jump_or_nops(old_addr, ip, old_insns, is_call); + if (ret) + return ret; + + if (memcmp(ip, old_insns, LOONGARCH_LONG_JUMP_NBYTES)) + return -EFAULT; + + ret = emit_jump_or_nops(new_addr, ip, new_insns, is_call); + if (ret) + return ret; + + mutex_lock(&text_mutex); + if (memcmp(ip, new_insns, LOONGARCH_LONG_JUMP_NBYTES)) + ret = larch_insn_text_copy(ip, new_insns, LOONGARCH_LONG_JUMP_NBYTES); + mutex_unlock(&text_mutex); + + return ret; +} + +int bpf_arch_text_invalidate(void *dst, size_t len) +{ + int i; + int ret = 0; + u32 *inst; + + inst = kvmalloc(len, GFP_KERNEL); + if (!inst) + return -ENOMEM; + + for (i = 0; i < (len / sizeof(u32)); i++) + inst[i] = INSN_BREAK; + + mutex_lock(&text_mutex); + if (larch_insn_text_copy(dst, inst, len)) + ret = -EINVAL; + mutex_unlock(&text_mutex); + + kvfree(inst); + + return ret; +} + +static void store_args(struct jit_ctx *ctx, int nargs, int args_off) +{ + int i; + + for (i = 0; i < nargs; i++) { + emit_insn(ctx, std, LOONGARCH_GPR_A0 + i, LOONGARCH_GPR_FP, -args_off); + args_off -= 8; + } +} + +static void restore_args(struct jit_ctx *ctx, int nargs, int args_off) +{ + int i; + + for (i = 0; i < nargs; i++) { + emit_insn(ctx, ldd, LOONGARCH_GPR_A0 + i, LOONGARCH_GPR_FP, -args_off); + args_off -= 8; + } +} + +static int invoke_bpf_prog(struct jit_ctx *ctx, struct bpf_tramp_link *l, + int args_off, int retval_off, int run_ctx_off, bool save_ret) +{ + int ret; + u32 *branch; + struct bpf_prog *p = l->link.prog; + int cookie_off = offsetof(struct bpf_tramp_run_ctx, bpf_cookie); + + if (l->cookie) { + move_imm(ctx, LOONGARCH_GPR_T1, l->cookie, false); + emit_insn(ctx, std, LOONGARCH_GPR_T1, LOONGARCH_GPR_FP, -run_ctx_off + cookie_off); + } else { + emit_insn(ctx, std, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_FP, -run_ctx_off + cookie_off); + } + + /* arg1: prog */ + move_imm(ctx, LOONGARCH_GPR_A0, (const s64)p, false); + /* arg2: &run_ctx */ + emit_insn(ctx, addid, LOONGARCH_GPR_A1, LOONGARCH_GPR_FP, -run_ctx_off); + ret = emit_call(ctx, (const u64)bpf_trampoline_enter(p)); + if (ret) + return ret; + + /* store prog start time */ + move_reg(ctx, LOONGARCH_GPR_S1, LOONGARCH_GPR_A0); + + /* + * if (__bpf_prog_enter(prog) == 0) + * goto skip_exec_of_prog; + */ + branch = (u32 *)ctx->image + ctx->idx; + /* nop reserved for conditional jump */ + emit_insn(ctx, nop); + + /* arg1: &args_off */ + emit_insn(ctx, addid, LOONGARCH_GPR_A0, LOONGARCH_GPR_FP, -args_off); + if (!p->jited) + move_imm(ctx, LOONGARCH_GPR_A1, (const s64)p->insnsi, false); + ret = emit_call(ctx, (const u64)p->bpf_func); + if (ret) + return ret; + + if (save_ret) { + emit_insn(ctx, std, LOONGARCH_GPR_A0, LOONGARCH_GPR_FP, -retval_off); + emit_insn(ctx, std, regmap[BPF_REG_0], LOONGARCH_GPR_FP, -(retval_off - 8)); + } + + /* update branch with beqz */ + if (ctx->image) { + int offset = (void *)(&ctx->image[ctx->idx]) - (void *)branch; + *branch = larch_insn_gen_beq(LOONGARCH_GPR_A0, LOONGARCH_GPR_ZERO, offset); + } + + /* arg1: prog */ + move_imm(ctx, LOONGARCH_GPR_A0, (const s64)p, false); + /* arg2: prog start time */ + move_reg(ctx, LOONGARCH_GPR_A1, LOONGARCH_GPR_S1); + /* arg3: &run_ctx */ + emit_insn(ctx, addid, LOONGARCH_GPR_A2, LOONGARCH_GPR_FP, -run_ctx_off); + ret = emit_call(ctx, (const u64)bpf_trampoline_exit(p)); + + return ret; +} + +static void invoke_bpf_mod_ret(struct jit_ctx *ctx, struct bpf_tramp_links *tl, + int args_off, int retval_off, int run_ctx_off, u32 **branches) +{ + int i; + + emit_insn(ctx, std, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_FP, -retval_off); + for (i = 0; i < tl->nr_links; i++) { + invoke_bpf_prog(ctx, tl->links[i], args_off, retval_off, run_ctx_off, true); + emit_insn(ctx, ldd, LOONGARCH_GPR_T1, LOONGARCH_GPR_FP, -retval_off); + branches[i] = (u32 *)ctx->image + ctx->idx; + emit_insn(ctx, nop); + } +} + +void *arch_alloc_bpf_trampoline(unsigned int size) +{ + return bpf_prog_pack_alloc(size, jit_fill_hole); +} + +void arch_free_bpf_trampoline(void *image, unsigned int size) +{ + bpf_prog_pack_free(image, size); +} + +static int __arch_prepare_bpf_trampoline(struct jit_ctx *ctx, struct bpf_tramp_image *im, + const struct btf_func_model *m, struct bpf_tramp_links *tlinks, + void *func_addr, u32 flags) +{ + int i, ret, save_ret; + int stack_size = 0, nargs = 0; + int retval_off, args_off, nargs_off, ip_off, run_ctx_off, sreg_off, tcc_ptr_off; + bool is_struct_ops = flags & BPF_TRAMP_F_INDIRECT; + void *orig_call = func_addr; + 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]; + u32 **branches = NULL; + + if (flags & (BPF_TRAMP_F_ORIG_STACK | BPF_TRAMP_F_SHARE_IPMODIFY)) + return -ENOTSUPP; + + /* + * 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 + * + * FP - retval_off [ return value ] BPF_TRAMP_F_CALL_ORIG or + * BPF_TRAMP_F_RET_FENTRY_RET + * [ argN ] + * [ ... ] + * FP - args_off [ arg1 ] + * + * FP - nargs_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 ] + * + * FP - tcc_ptr_off [ tail_call_cnt_ptr ] + */ + + if (m->nr_args > LOONGARCH_MAX_REG_ARGS) + return -ENOTSUPP; + + if (flags & (BPF_TRAMP_F_ORIG_STACK | BPF_TRAMP_F_SHARE_IPMODIFY)) + return -ENOTSUPP; + + stack_size = 0; + + /* 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) { + /* Save BPF R0 and A0 */ + stack_size += 16; + retval_off = stack_size; + } + + /* Room of trampoline frame to store args */ + nargs = m->nr_args; + stack_size += nargs * 8; + args_off = stack_size; + + /* Room of trampoline frame to store args number */ + stack_size += 8; + nargs_off = stack_size; + + /* Room of trampoline frame to store ip address */ + if (flags & BPF_TRAMP_F_IP_ARG) { + stack_size += 8; + ip_off = stack_size; + } + + /* Room of trampoline frame to store struct bpf_tramp_run_ctx */ + stack_size += round_up(sizeof(struct bpf_tramp_run_ctx), 8); + run_ctx_off = stack_size; + + stack_size += 8; + sreg_off = stack_size; + + /* Room of trampoline frame to store tail_call_cnt_ptr */ + if (flags & BPF_TRAMP_F_TAIL_CALL_CTX) { + stack_size += 8; + tcc_ptr_off = stack_size; + } + + stack_size = round_up(stack_size, 16); + + if (is_struct_ops) { + /* + * For the trampoline called directly, just handle + * the frame of trampoline. + */ + emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, -stack_size); + emit_insn(ctx, std, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, stack_size - 8); + emit_insn(ctx, std, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size - 16); + emit_insn(ctx, addid, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size); + } else { + /* + * For the trampoline called from function entry, + * the frame of traced function and the frame of + * trampoline need to be considered. + */ + /* RA and FP for parent function */ + emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, -16); + emit_insn(ctx, std, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, 8); + emit_insn(ctx, std, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, 0); + emit_insn(ctx, addid, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, 16); + + /* RA and FP for traced function */ + emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, -stack_size); + emit_insn(ctx, std, LOONGARCH_GPR_T0, LOONGARCH_GPR_SP, stack_size - 8); + emit_insn(ctx, std, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size - 16); + emit_insn(ctx, addid, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size); + } + + if (flags & BPF_TRAMP_F_TAIL_CALL_CTX) + emit_insn(ctx, std, REG_TCC, LOONGARCH_GPR_FP, -tcc_ptr_off); + + /* callee saved register S1 to pass start time */ + emit_insn(ctx, std, LOONGARCH_GPR_S1, LOONGARCH_GPR_FP, -sreg_off); + + /* store ip address of the traced function */ + if (flags & BPF_TRAMP_F_IP_ARG) { + move_imm(ctx, LOONGARCH_GPR_T1, (const s64)func_addr, false); + emit_insn(ctx, std, LOONGARCH_GPR_T1, LOONGARCH_GPR_FP, -ip_off); + } + + /* store nargs number */ + move_imm(ctx, LOONGARCH_GPR_T1, nargs, false); + emit_insn(ctx, std, LOONGARCH_GPR_T1, LOONGARCH_GPR_FP, -nargs_off); + + store_args(ctx, nargs, args_off); + + /* To traced function */ + /* Ftrace jump skips 2 NOP instructions */ + if (is_kernel_text((unsigned long)orig_call)) + orig_call += LOONGARCH_FENTRY_NBYTES; + /* Direct jump skips 5 NOP instructions */ + else if (is_bpf_text_address((unsigned long)orig_call)) + orig_call += LOONGARCH_BPF_FENTRY_NBYTES; + + if (flags & BPF_TRAMP_F_CALL_ORIG) { + move_imm(ctx, LOONGARCH_GPR_A0, (const s64)im, false); + ret = emit_call(ctx, (const u64)__bpf_tramp_enter); + if (ret) + return ret; + } + + for (i = 0; i < fentry->nr_links; i++) { + ret = invoke_bpf_prog(ctx, fentry->links[i], args_off, retval_off, + run_ctx_off, flags & BPF_TRAMP_F_RET_FENTRY_RET); + if (ret) + return ret; + } + if (fmod_ret->nr_links) { + branches = kcalloc(fmod_ret->nr_links, sizeof(u32 *), GFP_KERNEL); + if (!branches) + return -ENOMEM; + + invoke_bpf_mod_ret(ctx, fmod_ret, args_off, retval_off, run_ctx_off, branches); + } + + if (flags & BPF_TRAMP_F_CALL_ORIG) { + restore_args(ctx, m->nr_args, args_off); + + if (flags & BPF_TRAMP_F_TAIL_CALL_CTX) + emit_insn(ctx, ldd, REG_TCC, LOONGARCH_GPR_FP, -tcc_ptr_off); + + ret = emit_call(ctx, (const u64)orig_call); + if (ret) + goto out; + emit_insn(ctx, std, LOONGARCH_GPR_A0, LOONGARCH_GPR_FP, -retval_off); + emit_insn(ctx, std, regmap[BPF_REG_0], LOONGARCH_GPR_FP, -(retval_off - 8)); + im->ip_after_call = ctx->ro_image + ctx->idx; + /* Reserve space for the move_imm + jirl instruction */ + for (i = 0; i < LOONGARCH_LONG_JUMP_NINSNS; i++) + emit_insn(ctx, nop); + } + + for (i = 0; ctx->image && i < fmod_ret->nr_links; i++) { + int offset = (void *)(&ctx->image[ctx->idx]) - (void *)branches[i]; + *branches[i] = larch_insn_gen_bne(LOONGARCH_GPR_T1, LOONGARCH_GPR_ZERO, offset); + } + + for (i = 0; i < fexit->nr_links; i++) { + ret = invoke_bpf_prog(ctx, fexit->links[i], args_off, retval_off, run_ctx_off, false); + if (ret) + goto out; + } + + if (flags & BPF_TRAMP_F_CALL_ORIG) { + im->ip_epilogue = ctx->ro_image + ctx->idx; + move_imm(ctx, LOONGARCH_GPR_A0, (const s64)im, false); + ret = emit_call(ctx, (const u64)__bpf_tramp_exit); + if (ret) + goto out; + } + + if (flags & BPF_TRAMP_F_RESTORE_REGS) + restore_args(ctx, m->nr_args, args_off); + + if (save_ret) { + emit_insn(ctx, ldd, LOONGARCH_GPR_A0, LOONGARCH_GPR_FP, -retval_off); + emit_insn(ctx, ldd, regmap[BPF_REG_0], LOONGARCH_GPR_FP, -(retval_off - 8)); + } + + emit_insn(ctx, ldd, LOONGARCH_GPR_S1, LOONGARCH_GPR_FP, -sreg_off); + + if (flags & BPF_TRAMP_F_TAIL_CALL_CTX) + emit_insn(ctx, ldd, REG_TCC, LOONGARCH_GPR_FP, -tcc_ptr_off); + + if (is_struct_ops) { + /* trampoline called directly */ + emit_insn(ctx, ldd, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, stack_size - 8); + emit_insn(ctx, ldd, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size - 16); + emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, stack_size); + + emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_RA, 0); + } else { + /* trampoline called from function entry */ + emit_insn(ctx, ldd, LOONGARCH_GPR_T0, LOONGARCH_GPR_SP, stack_size - 8); + emit_insn(ctx, ldd, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size - 16); + emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, stack_size); + + emit_insn(ctx, ldd, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, 8); + emit_insn(ctx, ldd, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, 0); + emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, 16); + + if (flags & BPF_TRAMP_F_SKIP_FRAME) + /* return to parent function */ + emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_RA, 0); + else + /* return to traced function */ + emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_T0, 0); + } + + ret = ctx->idx; +out: + kfree(branches); + + return ret; +} + +int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *ro_image, + void *ro_image_end, const struct btf_func_model *m, + u32 flags, struct bpf_tramp_links *tlinks, void *func_addr) +{ + int ret, size; + void *image, *tmp; + struct jit_ctx ctx; + + size = ro_image_end - ro_image; + image = kvmalloc(size, GFP_KERNEL); + if (!image) + return -ENOMEM; + + ctx.image = (union loongarch_instruction *)image; + ctx.ro_image = (union loongarch_instruction *)ro_image; + ctx.idx = 0; + + jit_fill_hole(image, (unsigned int)(ro_image_end - ro_image)); + ret = __arch_prepare_bpf_trampoline(&ctx, im, m, tlinks, func_addr, flags); + if (ret > 0 && validate_code(&ctx) < 0) { + ret = -EINVAL; + goto out; + } + + tmp = bpf_arch_text_copy(ro_image, image, size); + if (IS_ERR(tmp)) { + ret = PTR_ERR(tmp); + goto out; + } + + bpf_flush_icache(ro_image, ro_image_end); +out: + kvfree(image); + return ret < 0 ? ret : size; +} + +int arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags, + struct bpf_tramp_links *tlinks, void *func_addr) +{ + int ret; + struct jit_ctx ctx; + struct bpf_tramp_image im; + + ctx.image = NULL; + ctx.idx = 0; + + ret = __arch_prepare_bpf_trampoline(&ctx, &im, m, tlinks, func_addr, flags); + + /* Page align */ + return ret < 0 ? ret : round_up(ret * LOONGARCH_INSN_SIZE, PAGE_SIZE); +} + struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) { bool tmp_blinded = false, extra_pass = false; @@ -1280,7 +1850,7 @@ skip_init_ctx: build_epilogue(&ctx); /* 3. Extra pass to validate JITed code */ - if (validate_code(&ctx)) { + if (validate_ctx(&ctx)) { bpf_jit_binary_free(header); prog = orig_prog; goto out_offset; @@ -1334,7 +1904,6 @@ out: if (tmp_blinded) bpf_jit_prog_release_other(prog, prog == orig_prog ? tmp : orig_prog); - out_offset = -1; return prog; @@ -1346,6 +1915,16 @@ out_free: goto out_offset; } +bool bpf_jit_bypass_spec_v1(void) +{ + return true; +} + +bool bpf_jit_bypass_spec_v4(void) +{ + return true; +} + /* Indicate the JIT backend supports mixing bpf2bpf and tailcalls. */ bool bpf_jit_supports_subprog_tailcalls(void) { |