diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index d338f2a96bba..d6cfc4ee6820 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -591,6 +591,8 @@ struct bpf_insn_aux_data { * accepts callback function as a parameter. */ bool calls_callback; + /* registers alive before this instruction. */ + u16 live_regs_before; }; #define MAX_USED_MAPS 64 /* max number of maps accessed by one eBPF program */ @@ -748,7 +750,11 @@ struct bpf_verifier_env { struct { int *insn_state; int *insn_stack; + /* vector of instruction indexes sorted in post-order */ + int *insn_postorder; int cur_stack; + /* current position in the insn_postorder vector */ + int cur_postorder; } cfg; struct backtrack_state bt; struct bpf_insn_hist_entry *insn_hist; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index b6664d0f6914..4edb2db0f889 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -3360,6 +3360,15 @@ static int add_subprog_and_kfunc(struct bpf_verifier_env *env) return 0; } +static int jmp_offset(struct bpf_insn *insn) +{ + u8 code = insn->code; + + if (code == (BPF_JMP32 | BPF_JA)) + return insn->imm; + return insn->off; +} + static int check_subprogs(struct bpf_verifier_env *env) { int i, subprog_start, subprog_end, off, cur_subprog = 0; @@ -3386,10 +3395,7 @@ static int check_subprogs(struct bpf_verifier_env *env) goto next; if (BPF_OP(code) == BPF_EXIT || BPF_OP(code) == BPF_CALL) goto next; - if (code == (BPF_JMP32 | BPF_JA)) - off = i + insn[i].imm + 1; - else - off = i + insn[i].off + 1; + off = i + jmp_offset(&insn[i]) + 1; if (off < subprog_start || off >= subprog_end) { verbose(env, "jump out of range from insn %d to %d\n", i, off); return -EINVAL; @@ -3919,6 +3925,17 @@ static const char *disasm_kfunc_name(void *data, const struct bpf_insn *insn) return btf_name_by_offset(desc_btf, func->name_off); } +static void verbose_insn(struct bpf_verifier_env *env, struct bpf_insn *insn) +{ + const struct bpf_insn_cbs cbs = { + .cb_call = disasm_kfunc_name, + .cb_print = verbose, + .private_data = env, + }; + + print_bpf_insn(&cbs, insn, env->allow_ptr_leaks); +} + static inline void bt_init(struct backtrack_state *bt, u32 frame) { bt->frame = frame; @@ -4119,11 +4136,6 @@ static bool calls_callback(struct bpf_verifier_env *env, int insn_idx); static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx, struct bpf_insn_hist_entry *hist, struct backtrack_state *bt) { - const struct bpf_insn_cbs cbs = { - .cb_call = disasm_kfunc_name, - .cb_print = verbose, - .private_data = env, - }; struct bpf_insn *insn = env->prog->insnsi + idx; u8 class = BPF_CLASS(insn->code); u8 opcode = BPF_OP(insn->code); @@ -4141,7 +4153,7 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx, fmt_stack_mask(env->tmp_str_buf, TMP_STR_BUF_LEN, bt_stack_mask(bt)); verbose(env, "stack=%s before ", env->tmp_str_buf); verbose(env, "%d: ", idx); - print_bpf_insn(&cbs, insn, env->allow_ptr_leaks); + verbose_insn(env, insn); } /* If there is a history record that some registers gained range at this insn, @@ -17007,27 +17019,6 @@ static int visit_func_call_insn(int t, struct bpf_insn *insns, /* Bitmask with 1s for all caller saved registers */ #define ALL_CALLER_SAVED_REGS ((1u << CALLER_SAVED_REGS) - 1) -/* Return a bitmask specifying which caller saved registers are - * clobbered by a call to a helper *as if* this helper follows - * bpf_fastcall contract: - * - includes R0 if function is non-void; - * - includes R1-R5 if corresponding parameter has is described - * in the function prototype. - */ -static u32 helper_fastcall_clobber_mask(const struct bpf_func_proto *fn) -{ - u32 mask; - int i; - - mask = 0; - if (fn->ret_type != RET_VOID) - mask |= BIT(BPF_REG_0); - for (i = 0; i < ARRAY_SIZE(fn->arg_type); ++i) - if (fn->arg_type[i] != ARG_DONTCARE) - mask |= BIT(BPF_REG_1 + i); - return mask; -} - /* True if do_misc_fixups() replaces calls to helper number 'imm', * replacement patch is presumed to follow bpf_fastcall contract * (see mark_fastcall_pattern_for_call() below). @@ -17044,24 +17035,54 @@ static bool verifier_inlines_helper_call(struct bpf_verifier_env *env, s32 imm) } } -/* Same as helper_fastcall_clobber_mask() but for kfuncs, see comment above */ -static u32 kfunc_fastcall_clobber_mask(struct bpf_kfunc_call_arg_meta *meta) -{ - u32 vlen, i, mask; +struct call_summary { + u8 num_params; + bool is_void; + bool fastcall; +}; - vlen = btf_type_vlen(meta->func_proto); - mask = 0; - if (!btf_type_is_void(btf_type_by_id(meta->btf, meta->func_proto->type))) - mask |= BIT(BPF_REG_0); - for (i = 0; i < vlen; ++i) - mask |= BIT(BPF_REG_1 + i); - return mask; -} - -/* Same as verifier_inlines_helper_call() but for kfuncs, see comment above */ -static bool is_fastcall_kfunc_call(struct bpf_kfunc_call_arg_meta *meta) +/* If @call is a kfunc or helper call, fills @cs and returns true, + * otherwise returns false. + */ +static bool get_call_summary(struct bpf_verifier_env *env, struct bpf_insn *call, + struct call_summary *cs) { - return meta->kfunc_flags & KF_FASTCALL; + struct bpf_kfunc_call_arg_meta meta; + const struct bpf_func_proto *fn; + int i; + + if (bpf_helper_call(call)) { + + if (get_helper_proto(env, call->imm, &fn) < 0) + /* error would be reported later */ + return false; + cs->fastcall = fn->allow_fastcall && + (verifier_inlines_helper_call(env, call->imm) || + bpf_jit_inlines_helper_call(call->imm)); + cs->is_void = fn->ret_type == RET_VOID; + cs->num_params = 0; + for (i = 0; i < ARRAY_SIZE(fn->arg_type); ++i) { + if (fn->arg_type[i] == ARG_DONTCARE) + break; + cs->num_params++; + } + return true; + } + + if (bpf_pseudo_kfunc_call(call)) { + int err; + + err = fetch_kfunc_meta(env, call, &meta, NULL); + if (err < 0) + /* error would be reported later */ + return false; + cs->num_params = btf_type_vlen(meta.func_proto); + cs->fastcall = meta.kfunc_flags & KF_FASTCALL; + cs->is_void = btf_type_is_void(btf_type_by_id(meta.btf, meta.func_proto->type)); + return true; + } + + return false; } /* LLVM define a bpf_fastcall function attribute. @@ -17144,39 +17165,23 @@ static void mark_fastcall_pattern_for_call(struct bpf_verifier_env *env, { struct bpf_insn *insns = env->prog->insnsi, *stx, *ldx; struct bpf_insn *call = &env->prog->insnsi[insn_idx]; - const struct bpf_func_proto *fn; - u32 clobbered_regs_mask = ALL_CALLER_SAVED_REGS; + u32 clobbered_regs_mask; + struct call_summary cs; u32 expected_regs_mask; - bool can_be_inlined = false; s16 off; int i; - if (bpf_helper_call(call)) { - if (get_helper_proto(env, call->imm, &fn) < 0) - /* error would be reported later */ - return; - clobbered_regs_mask = helper_fastcall_clobber_mask(fn); - can_be_inlined = fn->allow_fastcall && - (verifier_inlines_helper_call(env, call->imm) || - bpf_jit_inlines_helper_call(call->imm)); - } - - if (bpf_pseudo_kfunc_call(call)) { - struct bpf_kfunc_call_arg_meta meta; - int err; - - err = fetch_kfunc_meta(env, call, &meta, NULL); - if (err < 0) - /* error would be reported later */ - return; - - clobbered_regs_mask = kfunc_fastcall_clobber_mask(&meta); - can_be_inlined = is_fastcall_kfunc_call(&meta); - } - - if (clobbered_regs_mask == ALL_CALLER_SAVED_REGS) + if (!get_call_summary(env, call, &cs)) return; + /* A bitmask specifying which caller saved registers are clobbered + * by a call to a helper/kfunc *as if* this helper/kfunc follows + * bpf_fastcall contract: + * - includes R0 if function is non-void; + * - includes R1-R5 if corresponding parameter has is described + * in the function prototype. + */ + clobbered_regs_mask = GENMASK(cs.num_params, cs.is_void ? 1 : 0); /* e.g. if helper call clobbers r{0,1}, expect r{2,3,4,5} in the pattern */ expected_regs_mask = ~clobbered_regs_mask & ALL_CALLER_SAVED_REGS; @@ -17234,7 +17239,7 @@ static void mark_fastcall_pattern_for_call(struct bpf_verifier_env *env, * don't set 'fastcall_spills_num' for call B so that remove_fastcall_spills_fills() * does not remove spill/fill pair {4,6}. */ - if (can_be_inlined) + if (cs.fastcall) env->insn_aux_data[insn_idx].fastcall_spills_num = i - 1; else subprog->keep_fastcall_stack = 1; @@ -17397,9 +17402,8 @@ static int visit_insn(int t, struct bpf_verifier_env *env) static int check_cfg(struct bpf_verifier_env *env) { int insn_cnt = env->prog->len; - int *insn_stack, *insn_state; + int *insn_stack, *insn_state, *insn_postorder; int ex_insn_beg, i, ret = 0; - bool ex_done = false; insn_state = env->cfg.insn_state = kvcalloc(insn_cnt, sizeof(int), GFP_KERNEL); if (!insn_state) @@ -17411,6 +17415,17 @@ static int check_cfg(struct bpf_verifier_env *env) return -ENOMEM; } + insn_postorder = env->cfg.insn_postorder = kvcalloc(insn_cnt, sizeof(int), GFP_KERNEL); + if (!insn_postorder) { + kvfree(insn_state); + kvfree(insn_stack); + return -ENOMEM; + } + + ex_insn_beg = env->exception_callback_subprog + ? env->subprog_info[env->exception_callback_subprog].start + : 0; + insn_state[0] = DISCOVERED; /* mark 1st insn as discovered */ insn_stack[0] = 0; /* 0 is the first instruction */ env->cfg.cur_stack = 1; @@ -17424,6 +17439,7 @@ static int check_cfg(struct bpf_verifier_env *env) case DONE_EXPLORING: insn_state[t] = EXPLORED; env->cfg.cur_stack--; + insn_postorder[env->cfg.cur_postorder++] = t; break; case KEEP_EXPLORING: break; @@ -17442,13 +17458,10 @@ static int check_cfg(struct bpf_verifier_env *env) goto err_free; } - if (env->exception_callback_subprog && !ex_done) { - ex_insn_beg = env->subprog_info[env->exception_callback_subprog].start; - + if (ex_insn_beg && insn_state[ex_insn_beg] != EXPLORED) { insn_state[ex_insn_beg] = DISCOVERED; insn_stack[0] = ex_insn_beg; env->cfg.cur_stack = 1; - ex_done = true; goto walk_cfg; } @@ -18487,15 +18500,17 @@ static bool refsafe(struct bpf_verifier_state *old, struct bpf_verifier_state *c * the current state will reach 'bpf_exit' instruction safely */ static bool func_states_equal(struct bpf_verifier_env *env, struct bpf_func_state *old, - struct bpf_func_state *cur, enum exact_level exact) + struct bpf_func_state *cur, u32 insn_idx, enum exact_level exact) { - int i; + u16 live_regs = env->insn_aux_data[insn_idx].live_regs_before; + u16 i; if (old->callback_depth > cur->callback_depth) return false; for (i = 0; i < MAX_BPF_REG; i++) - if (!regsafe(env, &old->regs[i], &cur->regs[i], + if (((1 << i) & live_regs) && + !regsafe(env, &old->regs[i], &cur->regs[i], &env->idmap_scratch, exact)) return false; @@ -18516,6 +18531,7 @@ static bool states_equal(struct bpf_verifier_env *env, struct bpf_verifier_state *cur, enum exact_level exact) { + u32 insn_idx; int i; if (old->curframe != cur->curframe) @@ -18539,9 +18555,12 @@ static bool states_equal(struct bpf_verifier_env *env, * and all frame states need to be equivalent */ for (i = 0; i <= old->curframe; i++) { + insn_idx = i == old->curframe + ? env->insn_idx + : old->frame[i + 1]->callsite; if (old->frame[i]->callsite != cur->frame[i]->callsite) return false; - if (!func_states_equal(env, old->frame[i], cur->frame[i], exact)) + if (!func_states_equal(env, old->frame[i], cur->frame[i], insn_idx, exact)) return false; } return true; @@ -19273,19 +19292,13 @@ static int do_check(struct bpf_verifier_env *env) } if (env->log.level & BPF_LOG_LEVEL) { - const struct bpf_insn_cbs cbs = { - .cb_call = disasm_kfunc_name, - .cb_print = verbose, - .private_data = env, - }; - if (verifier_state_scratched(env)) print_insn_state(env, state, state->curframe); verbose_linfo(env, env->insn_idx, "; "); env->prev_log_pos = env->log.end_pos; verbose(env, "%d: ", env->insn_idx); - print_bpf_insn(&cbs, insn, env->allow_ptr_leaks); + verbose_insn(env, insn); env->prev_insn_print_pos = env->log.end_pos - env->prev_log_pos; env->prev_log_pos = env->log.end_pos; } @@ -23380,6 +23393,301 @@ static int process_fd_array(struct bpf_verifier_env *env, union bpf_attr *attr, return 0; } +static bool can_fallthrough(struct bpf_insn *insn) +{ + u8 class = BPF_CLASS(insn->code); + u8 opcode = BPF_OP(insn->code); + + if (class != BPF_JMP && class != BPF_JMP32) + return true; + + if (opcode == BPF_EXIT || opcode == BPF_JA) + return false; + + return true; +} + +static bool can_jump(struct bpf_insn *insn) +{ + u8 class = BPF_CLASS(insn->code); + u8 opcode = BPF_OP(insn->code); + + if (class != BPF_JMP && class != BPF_JMP32) + return false; + + switch (opcode) { + case BPF_JA: + case BPF_JEQ: + case BPF_JNE: + case BPF_JLT: + case BPF_JLE: + case BPF_JGT: + case BPF_JGE: + case BPF_JSGT: + case BPF_JSGE: + case BPF_JSLT: + case BPF_JSLE: + case BPF_JCOND: + return true; + } + + return false; +} + +static int insn_successors(struct bpf_prog *prog, u32 idx, u32 succ[2]) +{ + struct bpf_insn *insn = &prog->insnsi[idx]; + int i = 0, insn_sz; + u32 dst; + + insn_sz = bpf_is_ldimm64(insn) ? 2 : 1; + if (can_fallthrough(insn) && idx + 1 < prog->len) + succ[i++] = idx + insn_sz; + + if (can_jump(insn)) { + dst = idx + jmp_offset(insn) + 1; + if (i == 0 || succ[0] != dst) + succ[i++] = dst; + } + + return i; +} + +/* Each field is a register bitmask */ +struct insn_live_regs { + u16 use; /* registers read by instruction */ + u16 def; /* registers written by instruction */ + u16 in; /* registers that may be alive before instruction */ + u16 out; /* registers that may be alive after instruction */ +}; + +/* Bitmask with 1s for all caller saved registers */ +#define ALL_CALLER_SAVED_REGS ((1u << CALLER_SAVED_REGS) - 1) + +/* Compute info->{use,def} fields for the instruction */ +static void compute_insn_live_regs(struct bpf_verifier_env *env, + struct bpf_insn *insn, + struct insn_live_regs *info) +{ + struct call_summary cs; + u8 class = BPF_CLASS(insn->code); + u8 code = BPF_OP(insn->code); + u8 mode = BPF_MODE(insn->code); + u16 src = BIT(insn->src_reg); + u16 dst = BIT(insn->dst_reg); + u16 r0 = BIT(0); + u16 def = 0; + u16 use = 0xffff; + + switch (class) { + case BPF_LD: + switch (mode) { + case BPF_IMM: + if (BPF_SIZE(insn->code) == BPF_DW) { + def = dst; + use = 0; + } + break; + case BPF_LD | BPF_ABS: + case BPF_LD | BPF_IND: + /* stick with defaults */ + break; + } + break; + case BPF_LDX: + switch (mode) { + case BPF_MEM: + case BPF_MEMSX: + def = dst; + use = src; + break; + } + break; + case BPF_ST: + switch (mode) { + case BPF_MEM: + def = 0; + use = dst; + break; + } + break; + case BPF_STX: + switch (mode) { + case BPF_MEM: + def = 0; + use = dst | src; + break; + case BPF_ATOMIC: + switch (insn->imm) { + case BPF_CMPXCHG: + use = r0 | dst | src; + def = r0; + break; + case BPF_LOAD_ACQ: + def = dst; + use = src; + break; + case BPF_STORE_REL: + def = 0; + use = dst | src; + break; + default: + use = dst | src; + if (insn->imm & BPF_FETCH) + def = src; + else + def = 0; + } + break; + } + break; + case BPF_ALU: + case BPF_ALU64: + switch (code) { + case BPF_END: + use = dst; + def = dst; + break; + case BPF_MOV: + def = dst; + if (BPF_SRC(insn->code) == BPF_K) + use = 0; + else + use = src; + break; + default: + def = dst; + if (BPF_SRC(insn->code) == BPF_K) + use = dst; + else + use = dst | src; + } + break; + case BPF_JMP: + case BPF_JMP32: + switch (code) { + case BPF_JA: + def = 0; + use = 0; + break; + case BPF_EXIT: + def = 0; + use = r0; + break; + case BPF_CALL: + def = ALL_CALLER_SAVED_REGS; + use = def & ~BIT(BPF_REG_0); + if (get_call_summary(env, insn, &cs)) + use = GENMASK(cs.num_params, 1); + break; + default: + def = 0; + if (BPF_SRC(insn->code) == BPF_K) + use = dst; + else + use = dst | src; + } + break; + } + + info->def = def; + info->use = use; +} + +/* Compute may-live registers after each instruction in the program. + * The register is live after the instruction I if it is read by some + * instruction S following I during program execution and is not + * overwritten between I and S. + * + * Store result in env->insn_aux_data[i].live_regs. + */ +static int compute_live_registers(struct bpf_verifier_env *env) +{ + struct bpf_insn_aux_data *insn_aux = env->insn_aux_data; + struct bpf_insn *insns = env->prog->insnsi; + struct insn_live_regs *state; + int insn_cnt = env->prog->len; + int err = 0, i, j; + bool changed; + + /* Use the following algorithm: + * - define the following: + * - I.use : a set of all registers read by instruction I; + * - I.def : a set of all registers written by instruction I; + * - I.in : a set of all registers that may be alive before I execution; + * - I.out : a set of all registers that may be alive after I execution; + * - insn_successors(I): a set of instructions S that might immediately + * follow I for some program execution; + * - associate separate empty sets 'I.in' and 'I.out' with each instruction; + * - visit each instruction in a postorder and update + * state[i].in, state[i].out as follows: + * + * state[i].out = U [state[s].in for S in insn_successors(i)] + * state[i].in = (state[i].out / state[i].def) U state[i].use + * + * (where U stands for set union, / stands for set difference) + * - repeat the computation while {in,out} fields changes for + * any instruction. + */ + state = kvcalloc(insn_cnt, sizeof(*state), GFP_KERNEL); + if (!state) { + err = -ENOMEM; + goto out; + } + + for (i = 0; i < insn_cnt; ++i) + compute_insn_live_regs(env, &insns[i], &state[i]); + + changed = true; + while (changed) { + changed = false; + for (i = 0; i < env->cfg.cur_postorder; ++i) { + int insn_idx = env->cfg.insn_postorder[i]; + struct insn_live_regs *live = &state[insn_idx]; + int succ_num; + u32 succ[2]; + u16 new_out = 0; + u16 new_in = 0; + + succ_num = insn_successors(env->prog, insn_idx, succ); + for (int s = 0; s < succ_num; ++s) + new_out |= state[succ[s]].in; + new_in = (new_out & ~live->def) | live->use; + if (new_out != live->out || new_in != live->in) { + live->in = new_in; + live->out = new_out; + changed = true; + } + } + } + + for (i = 0; i < insn_cnt; ++i) + insn_aux[i].live_regs_before = state[i].in; + + if (env->log.level & BPF_LOG_LEVEL2) { + verbose(env, "Live regs before insn:\n"); + for (i = 0; i < insn_cnt; ++i) { + verbose(env, "%3d: ", i); + for (j = BPF_REG_0; j < BPF_REG_10; ++j) + if (insn_aux[i].live_regs_before & BIT(j)) + verbose(env, "%d", j); + else + verbose(env, "."); + verbose(env, " "); + verbose_insn(env, &insns[i]); + if (bpf_is_ldimm64(&insns[i])) + i++; + } + } + +out: + kvfree(state); + kvfree(env->cfg.insn_postorder); + env->cfg.insn_postorder = NULL; + env->cfg.cur_postorder = 0; + return err; +} + int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size) { u64 start_time = ktime_get_ns(); @@ -23501,6 +23809,10 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3 if (ret) goto skip_full_check; + ret = compute_live_registers(env); + if (ret < 0) + goto skip_full_check; + ret = mark_fastcall_patterns(env); if (ret < 0) goto skip_full_check; @@ -23639,6 +23951,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3 vfree(env->insn_aux_data); kvfree(env->insn_hist); err_free_env: + kvfree(env->cfg.insn_postorder); kvfree(env); return ret; } diff --git a/tools/testing/selftests/bpf/prog_tests/align.c b/tools/testing/selftests/bpf/prog_tests/align.c index 4ebd0da898f5..1d53a8561ee2 100644 --- a/tools/testing/selftests/bpf/prog_tests/align.c +++ b/tools/testing/selftests/bpf/prog_tests/align.c @@ -610,9 +610,11 @@ static int do_test_single(struct bpf_align_test *test) .log_size = sizeof(bpf_vlog), .log_level = 2, ); + const char *main_pass_start = "0: R1=ctx() R10=fp0"; const char *line_ptr; int cur_line = -1; int prog_len, i; + char *start; int fd_prog; int ret; @@ -632,7 +634,13 @@ static int do_test_single(struct bpf_align_test *test) ret = 0; /* We make a local copy so that we can strtok() it */ strncpy(bpf_vlog_copy, bpf_vlog, sizeof(bpf_vlog_copy)); - line_ptr = strtok(bpf_vlog_copy, "\n"); + start = strstr(bpf_vlog_copy, main_pass_start); + if (!start) { + ret = 1; + printf("Can't find initial line '%s'\n", main_pass_start); + goto out; + } + line_ptr = strtok(start, "\n"); for (i = 0; i < MAX_MATCHES; i++) { struct bpf_reg_match m = test->matches[i]; const char *p; @@ -682,6 +690,7 @@ static int do_test_single(struct bpf_align_test *test) break; } } +out: if (fd_prog >= 0) close(fd_prog); } diff --git a/tools/testing/selftests/bpf/prog_tests/compute_live_registers.c b/tools/testing/selftests/bpf/prog_tests/compute_live_registers.c new file mode 100644 index 000000000000..285f20241fe1 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/compute_live_registers.c @@ -0,0 +1,9 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "compute_live_registers.skel.h" +#include "test_progs.h" + +void test_compute_live_registers(void) +{ + RUN_TESTS(compute_live_registers); +} diff --git a/tools/testing/selftests/bpf/progs/bpf_misc.h b/tools/testing/selftests/bpf/progs/bpf_misc.h index 34f555da546f..13a2e22f5465 100644 --- a/tools/testing/selftests/bpf/progs/bpf_misc.h +++ b/tools/testing/selftests/bpf/progs/bpf_misc.h @@ -213,4 +213,21 @@ #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) #endif +#if (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86) || \ + (defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || \ + defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390) || \ + defined(__TARGET_ARCH_loongarch)) && \ + __clang_major__ >= 18 +#define CAN_USE_GOTOL +#endif + +#if _clang_major__ >= 18 +#define CAN_USE_BPF_ST +#endif + +#if __clang_major__ >= 18 && defined(ENABLE_ATOMICS_TESTS) && \ + (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86)) +#define CAN_USE_LOAD_ACQ_STORE_REL +#endif + #endif diff --git a/tools/testing/selftests/bpf/progs/compute_live_registers.c b/tools/testing/selftests/bpf/progs/compute_live_registers.c new file mode 100644 index 000000000000..14df92949e81 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/compute_live_registers.c @@ -0,0 +1,424 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include "../../../include/linux/filter.h" +#include "bpf_arena_common.h" +#include "bpf_misc.h" + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, __u64); +} test_map SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARENA); + __uint(map_flags, BPF_F_MMAPABLE); + __uint(max_entries, 1); +} arena SEC(".maps"); + +SEC("socket") +__log_level(2) +__msg(" 0: .......... (b7) r0 = 42") +__msg(" 1: 0......... (bf) r1 = r0") +__msg(" 2: .1........ (bf) r2 = r1") +__msg(" 3: ..2....... (bf) r3 = r2") +__msg(" 4: ...3...... (bf) r4 = r3") +__msg(" 5: ....4..... (bf) r5 = r4") +__msg(" 6: .....5.... (bf) r6 = r5") +__msg(" 7: ......6... (bf) r7 = r6") +__msg(" 8: .......7.. (bf) r8 = r7") +__msg(" 9: ........8. (bf) r9 = r8") +__msg("10: .........9 (bf) r0 = r9") +__msg("11: 0......... (95) exit") +__naked void assign_chain(void) +{ + asm volatile ( + "r0 = 42;" + "r1 = r0;" + "r2 = r1;" + "r3 = r2;" + "r4 = r3;" + "r5 = r4;" + "r6 = r5;" + "r7 = r6;" + "r8 = r7;" + "r9 = r8;" + "r0 = r9;" + "exit;" + ::: __clobber_all); +} + +SEC("socket") +__log_level(2) +__msg("0: .......... (b7) r1 = 7") +__msg("1: .1........ (07) r1 += 7") +__msg("2: .......... (b7) r2 = 7") +__msg("3: ..2....... (b7) r3 = 42") +__msg("4: ..23...... (0f) r2 += r3") +__msg("5: .......... (b7) r0 = 0") +__msg("6: 0......... (95) exit") +__naked void arithmetics(void) +{ + asm volatile ( + "r1 = 7;" + "r1 += 7;" + "r2 = 7;" + "r3 = 42;" + "r2 += r3;" + "r0 = 0;" + "exit;" + ::: __clobber_all); +} + +#ifdef CAN_USE_BPF_ST +SEC("socket") +__log_level(2) +__msg(" 1: .1........ (07) r1 += -8") +__msg(" 2: .1........ (7a) *(u64 *)(r1 +0) = 7") +__msg(" 3: .1........ (b7) r2 = 42") +__msg(" 4: .12....... (7b) *(u64 *)(r1 +0) = r2") +__msg(" 5: .12....... (7b) *(u64 *)(r1 +0) = r2") +__msg(" 6: .......... (b7) r0 = 0") +__naked void store(void) +{ + asm volatile ( + "r1 = r10;" + "r1 += -8;" + "*(u64 *)(r1 +0) = 7;" + "r2 = 42;" + "*(u64 *)(r1 +0) = r2;" + "*(u64 *)(r1 +0) = r2;" + "r0 = 0;" + "exit;" + ::: __clobber_all); +} +#endif + +SEC("socket") +__log_level(2) +__msg("1: ....4..... (07) r4 += -8") +__msg("2: ....4..... (79) r5 = *(u64 *)(r4 +0)") +__msg("3: ....45.... (07) r4 += -8") +__naked void load(void) +{ + asm volatile ( + "r4 = r10;" + "r4 += -8;" + "r5 = *(u64 *)(r4 +0);" + "r4 += -8;" + "r0 = r5;" + "exit;" + ::: __clobber_all); +} + +SEC("socket") +__log_level(2) +__msg("0: .1........ (61) r2 = *(u32 *)(r1 +0)") +__msg("1: ..2....... (d4) r2 = le64 r2") +__msg("2: ..2....... (bf) r0 = r2") +__naked void endian(void) +{ + asm volatile ( + "r2 = *(u32 *)(r1 +0);" + "r2 = le64 r2;" + "r0 = r2;" + "exit;" + ::: __clobber_all); +} + +SEC("socket") +__log_level(2) +__msg(" 8: 0......... (b7) r1 = 1") +__msg(" 9: 01........ (db) r1 = atomic64_fetch_add((u64 *)(r0 +0), r1)") +__msg("10: 01........ (c3) lock *(u32 *)(r0 +0) += r1") +__msg("11: 01........ (db) r1 = atomic64_xchg((u64 *)(r0 +0), r1)") +__msg("12: 01........ (bf) r2 = r0") +__msg("13: .12....... (bf) r0 = r1") +__msg("14: 012....... (db) r0 = atomic64_cmpxchg((u64 *)(r2 +0), r0, r1)") +__naked void atomic(void) +{ + asm volatile ( + "r2 = r10;" + "r2 += -8;" + "r1 = 0;" + "*(u64 *)(r2 +0) = r1;" + "r1 = %[test_map] ll;" + "call %[bpf_map_lookup_elem];" + "if r0 == 0 goto 1f;" + "r1 = 1;" + "r1 = atomic_fetch_add((u64 *)(r0 +0), r1);" + ".8byte %[add_nofetch];" /* same as "lock *(u32 *)(r0 +0) += r1;" */ + "r1 = xchg_64(r0 + 0, r1);" + "r2 = r0;" + "r0 = r1;" + "r0 = cmpxchg_64(r2 + 0, r0, r1);" + "1: exit;" + : + : __imm(bpf_map_lookup_elem), + __imm_addr(test_map), + __imm_insn(add_nofetch, BPF_ATOMIC_OP(BPF_W, BPF_ADD, BPF_REG_0, BPF_REG_1, 0)) + : __clobber_all); +} + +#ifdef CAN_USE_LOAD_ACQ_STORE_REL + +SEC("socket") +__log_level(2) +__msg("2: .12....... (db) store_release((u64 *)(r2 -8), r1)") +__msg("3: .......... (bf) r3 = r10") +__msg("4: ...3...... (db) r4 = load_acquire((u64 *)(r3 -8))") +__naked void atomic_load_acq_store_rel(void) +{ + asm volatile ( + "r1 = 42;" + "r2 = r10;" + ".8byte %[store_release_insn];" /* store_release((u64 *)(r2 - 8), r1); */ + "r3 = r10;" + ".8byte %[load_acquire_insn];" /* r4 = load_acquire((u64 *)(r3 + 0)); */ + "r0 = r4;" + "exit;" + : + : __imm_insn(store_release_insn, + BPF_ATOMIC_OP(BPF_DW, BPF_STORE_REL, BPF_REG_2, BPF_REG_1, -8)), + __imm_insn(load_acquire_insn, + BPF_ATOMIC_OP(BPF_DW, BPF_LOAD_ACQ, BPF_REG_4, BPF_REG_3, -8)) + : __clobber_all); +} + +#endif /* CAN_USE_LOAD_ACQ_STORE_REL */ + +SEC("socket") +__log_level(2) +__msg("4: .12....7.. (85) call bpf_trace_printk#6") +__msg("5: 0......7.. (0f) r0 += r7") +__naked void regular_call(void) +{ + asm volatile ( + "r7 = 1;" + "r1 = r10;" + "r1 += -8;" + "r2 = 1;" + "call %[bpf_trace_printk];" + "r0 += r7;" + "exit;" + : + : __imm(bpf_trace_printk) + : __clobber_all); +} + +SEC("socket") +__log_level(2) +__msg("2: 012....... (25) if r1 > 0x7 goto pc+1") +__msg("3: ..2....... (bf) r0 = r2") +__naked void if1(void) +{ + asm volatile ( + "r0 = 1;" + "r2 = 2;" + "if r1 > 0x7 goto +1;" + "r0 = r2;" + "exit;" + ::: __clobber_all); +} + +SEC("socket") +__log_level(2) +__msg("3: 0123...... (2d) if r1 > r3 goto pc+1") +__msg("4: ..2....... (bf) r0 = r2") +__naked void if2(void) +{ + asm volatile ( + "r0 = 1;" + "r2 = 2;" + "r3 = 7;" + "if r1 > r3 goto +1;" + "r0 = r2;" + "exit;" + ::: __clobber_all); +} + +SEC("socket") +__log_level(2) +__msg("0: .......... (b7) r1 = 0") +__msg("1: .1........ (b7) r2 = 7") +__msg("2: .12....... (25) if r1 > 0x7 goto pc+4") +__msg("3: .12....... (07) r1 += 1") +__msg("4: .12....... (27) r2 *= 2") +__msg("5: .12....... (05) goto pc+0") +__msg("6: .12....... (05) goto pc-5") +__msg("7: .......... (b7) r0 = 0") +__msg("8: 0......... (95) exit") +__naked void loop(void) +{ + asm volatile ( + "r1 = 0;" + "r2 = 7;" + "if r1 > 0x7 goto +4;" + "r1 += 1;" + "r2 *= 2;" + "goto +0;" + "goto -5;" + "r0 = 0;" + "exit;" + : + : __imm(bpf_trace_printk) + : __clobber_all); +} + +#ifdef CAN_USE_GOTOL +SEC("socket") +__log_level(2) +__msg("2: .123...... (25) if r1 > 0x7 goto pc+2") +__msg("3: ..2....... (bf) r0 = r2") +__msg("4: 0......... (06) gotol pc+1") +__msg("5: ...3...... (bf) r0 = r3") +__msg("6: 0......... (95) exit") +__naked void gotol(void) +{ + asm volatile ( + "r2 = 42;" + "r3 = 24;" + "if r1 > 0x7 goto +2;" + "r0 = r2;" + "gotol +1;" + "r0 = r3;" + "exit;" + : + : __imm(bpf_trace_printk) + : __clobber_all); +} +#endif + +SEC("socket") +__log_level(2) +__msg("0: 0......... (b7) r1 = 1") +__msg("1: 01........ (e5) may_goto pc+1") +__msg("2: 0......... (05) goto pc-3") +__msg("3: .1........ (bf) r0 = r1") +__msg("4: 0......... (95) exit") +__naked void may_goto(void) +{ + asm volatile ( + "1: r1 = 1;" + ".8byte %[may_goto];" + "goto 1b;" + "r0 = r1;" + "exit;" + : + : __imm(bpf_get_smp_processor_id), + __imm_insn(may_goto, BPF_RAW_INSN(BPF_JMP | BPF_JCOND, 0, 0, +1 /* offset */, 0)) + : __clobber_all); +} + +SEC("socket") +__log_level(2) +__msg("1: 0......... (18) r2 = 0x7") +__msg("3: 0.2....... (0f) r0 += r2") +__naked void ldimm64(void) +{ + asm volatile ( + "r0 = 0;" + "r2 = 0x7 ll;" + "r0 += r2;" + "exit;" + : + :: __clobber_all); +} + +/* No rules specific for LD_ABS/LD_IND, default behaviour kicks in */ +SEC("socket") +__log_level(2) +__msg("2: 0123456789 (30) r0 = *(u8 *)skb[42]") +__msg("3: 012.456789 (0f) r7 += r0") +__msg("4: 012.456789 (b7) r3 = 42") +__msg("5: 0123456789 (50) r0 = *(u8 *)skb[r3 + 0]") +__msg("6: 0......7.. (0f) r7 += r0") +__naked void ldabs(void) +{ + asm volatile ( + "r6 = r1;" + "r7 = 0;" + "r0 = *(u8 *)skb[42];" + "r7 += r0;" + "r3 = 42;" + ".8byte %[ld_ind];" /* same as "r0 = *(u8 *)skb[r3];" */ + "r7 += r0;" + "r0 = r7;" + "exit;" + : + : __imm_insn(ld_ind, BPF_LD_IND(BPF_B, BPF_REG_3, 0)) + : __clobber_all); +} + + +#ifdef __BPF_FEATURE_ADDR_SPACE_CAST +SEC("?fentry.s/" SYS_PREFIX "sys_getpgid") +__log_level(2) +__msg(" 6: .12345.... (85) call bpf_arena_alloc_pages") +__msg(" 7: 0......... (bf) r1 = addr_space_cast(r0, 0, 1)") +__msg(" 8: .1........ (b7) r2 = 42") +__naked void addr_space_cast(void) +{ + asm volatile ( + "r1 = %[arena] ll;" + "r2 = 0;" + "r3 = 1;" + "r4 = 0;" + "r5 = 0;" + "call %[bpf_arena_alloc_pages];" + "r1 = addr_space_cast(r0, 0, 1);" + "r2 = 42;" + "*(u64 *)(r1 +0) = r2;" + "r0 = 0;" + "exit;" + : + : __imm(bpf_arena_alloc_pages), + __imm_addr(arena) + : __clobber_all); +} +#endif + +static __used __naked int aux1(void) +{ + asm volatile ( + "r0 = r1;" + "r0 += r2;" + "exit;" + ::: __clobber_all); +} + +SEC("socket") +__log_level(2) +__msg("0: ....45.... (b7) r1 = 1") +__msg("1: .1..45.... (b7) r2 = 2") +__msg("2: .12.45.... (b7) r3 = 3") +/* Conservative liveness for subprog parameters. */ +__msg("3: .12345.... (85) call pc+2") +__msg("4: .......... (b7) r0 = 0") +__msg("5: 0......... (95) exit") +__msg("6: .12....... (bf) r0 = r1") +__msg("7: 0.2....... (0f) r0 += r2") +/* Conservative liveness for subprog return value. */ +__msg("8: 0......... (95) exit") +__naked void subprog1(void) +{ + asm volatile ( + "r1 = 1;" + "r2 = 2;" + "r3 = 3;" + "call aux1;" + "r0 = 0;" + "exit;" + ::: __clobber_all); +} + +/* to retain debug info for BTF generation */ +void kfunc_root(void) +{ + bpf_arena_alloc_pages(0, 0, 0, 0, 0); +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/verifier_gotol.c b/tools/testing/selftests/bpf/progs/verifier_gotol.c index 05a329ee45ee..d5d8f24df394 100644 --- a/tools/testing/selftests/bpf/progs/verifier_gotol.c +++ b/tools/testing/selftests/bpf/progs/verifier_gotol.c @@ -4,11 +4,7 @@ #include #include "bpf_misc.h" -#if (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86) || \ - (defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || \ - defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390) || \ - defined(__TARGET_ARCH_loongarch)) && \ - __clang_major__ >= 18 +#ifdef CAN_USE_GOTOL SEC("socket") __description("gotol, small_imm") diff --git a/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c b/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c index e54bb5385bc1..75dd922e4e9f 100644 --- a/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c +++ b/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c @@ -407,11 +407,7 @@ l0_%=: call %[bpf_jiffies64]; \ : __clobber_all); } -#if (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86) || \ - (defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || \ - defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390) || \ - defined(__TARGET_ARCH_loongarch)) && \ - __clang_major__ >= 18 +#ifdef CAN_USE_GOTOL SEC("socket") __success __retval(0) __naked void gotol_and_may_goto(void) diff --git a/tools/testing/selftests/bpf/progs/verifier_load_acquire.c b/tools/testing/selftests/bpf/progs/verifier_load_acquire.c index ff308f24d745..608097453832 100644 --- a/tools/testing/selftests/bpf/progs/verifier_load_acquire.c +++ b/tools/testing/selftests/bpf/progs/verifier_load_acquire.c @@ -6,8 +6,7 @@ #include "../../../include/linux/filter.h" #include "bpf_misc.h" -#if __clang_major__ >= 18 && defined(ENABLE_ATOMICS_TESTS) && \ - (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86)) +#ifdef CAN_USE_LOAD_ACQ_STORE_REL SEC("socket") __description("load-acquire, 8-bit") @@ -182,7 +181,7 @@ __naked void load_acquire_from_sock_pointer(void) : __clobber_all); } -#else +#else /* CAN_USE_LOAD_ACQ_STORE_REL */ SEC("socket") __description("Clang version < 18, ENABLE_ATOMICS_TESTS not defined, and/or JIT doesn't support load-acquire, use a dummy test") @@ -192,6 +191,6 @@ int dummy_test(void) return 0; } -#endif +#endif /* CAN_USE_LOAD_ACQ_STORE_REL */ char _license[] SEC("license") = "GPL";