|  | /* | 
|  | * QEMU Plugin API | 
|  | * | 
|  | * This provides the API that is available to the plugins to interact | 
|  | * with QEMU. We have to be careful not to expose internal details of | 
|  | * how QEMU works so we abstract out things like translation and | 
|  | * instructions to anonymous data types: | 
|  | * | 
|  | *  qemu_plugin_tb | 
|  | *  qemu_plugin_insn | 
|  | *  qemu_plugin_register | 
|  | * | 
|  | * Which can then be passed back into the API to do additional things. | 
|  | * As such all the public functions in here are exported in | 
|  | * qemu-plugin.h. | 
|  | * | 
|  | * The general life-cycle of a plugin is: | 
|  | * | 
|  | *  - plugin is loaded, public qemu_plugin_install called | 
|  | *    - the install func registers callbacks for events | 
|  | *    - usually an atexit_cb is registered to dump info at the end | 
|  | *  - when a registered event occurs the plugin is called | 
|  | *     - some events pass additional info | 
|  | *     - during translation the plugin can decide to instrument any | 
|  | *       instruction | 
|  | *  - when QEMU exits all the registered atexit callbacks are called | 
|  | * | 
|  | * Copyright (C) 2017, Emilio G. Cota <cota@braap.org> | 
|  | * Copyright (C) 2019, Linaro | 
|  | * | 
|  | * License: GNU GPL, version 2 or later. | 
|  | *   See the COPYING file in the top-level directory. | 
|  | * | 
|  | * SPDX-License-Identifier: GPL-2.0-or-later | 
|  | * | 
|  | */ | 
|  |  | 
|  | #include "qemu/osdep.h" | 
|  | #include "qemu/main-loop.h" | 
|  | #include "qemu/plugin.h" | 
|  | #include "qemu/log.h" | 
|  | #include "tcg/tcg.h" | 
|  | #include "exec/exec-all.h" | 
|  | #include "exec/gdbstub.h" | 
|  | #include "exec/translator.h" | 
|  | #include "disas/disas.h" | 
|  | #include "plugin.h" | 
|  | #ifndef CONFIG_USER_ONLY | 
|  | #include "exec/ram_addr.h" | 
|  | #include "qemu/plugin-memory.h" | 
|  | #include "hw/boards.h" | 
|  | #else | 
|  | #include "qemu.h" | 
|  | #ifdef CONFIG_LINUX | 
|  | #include "loader.h" | 
|  | #endif | 
|  | #endif | 
|  |  | 
|  | /* Uninstall and Reset handlers */ | 
|  |  | 
|  | void qemu_plugin_uninstall(qemu_plugin_id_t id, qemu_plugin_simple_cb_t cb) | 
|  | { | 
|  | plugin_reset_uninstall(id, cb, false); | 
|  | } | 
|  |  | 
|  | void qemu_plugin_reset(qemu_plugin_id_t id, qemu_plugin_simple_cb_t cb) | 
|  | { | 
|  | plugin_reset_uninstall(id, cb, true); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Plugin Register Functions | 
|  | * | 
|  | * This allows the plugin to register callbacks for various events | 
|  | * during the translation. | 
|  | */ | 
|  |  | 
|  | void qemu_plugin_register_vcpu_init_cb(qemu_plugin_id_t id, | 
|  | qemu_plugin_vcpu_simple_cb_t cb) | 
|  | { | 
|  | plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_INIT, cb); | 
|  | } | 
|  |  | 
|  | void qemu_plugin_register_vcpu_exit_cb(qemu_plugin_id_t id, | 
|  | qemu_plugin_vcpu_simple_cb_t cb) | 
|  | { | 
|  | plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_EXIT, cb); | 
|  | } | 
|  |  | 
|  | static bool tb_is_mem_only(void) | 
|  | { | 
|  | return tb_cflags(tcg_ctx->gen_tb) & CF_MEMI_ONLY; | 
|  | } | 
|  |  | 
|  | void qemu_plugin_register_vcpu_tb_exec_cb(struct qemu_plugin_tb *tb, | 
|  | qemu_plugin_vcpu_udata_cb_t cb, | 
|  | enum qemu_plugin_cb_flags flags, | 
|  | void *udata) | 
|  | { | 
|  | if (!tb_is_mem_only()) { | 
|  | plugin_register_dyn_cb__udata(&tb->cbs, cb, flags, udata); | 
|  | } | 
|  | } | 
|  |  | 
|  | void qemu_plugin_register_vcpu_tb_exec_cond_cb(struct qemu_plugin_tb *tb, | 
|  | qemu_plugin_vcpu_udata_cb_t cb, | 
|  | enum qemu_plugin_cb_flags flags, | 
|  | enum qemu_plugin_cond cond, | 
|  | qemu_plugin_u64 entry, | 
|  | uint64_t imm, | 
|  | void *udata) | 
|  | { | 
|  | if (cond == QEMU_PLUGIN_COND_NEVER || tb_is_mem_only()) { | 
|  | return; | 
|  | } | 
|  | if (cond == QEMU_PLUGIN_COND_ALWAYS) { | 
|  | qemu_plugin_register_vcpu_tb_exec_cb(tb, cb, flags, udata); | 
|  | return; | 
|  | } | 
|  | plugin_register_dyn_cond_cb__udata(&tb->cbs, cb, flags, | 
|  | cond, entry, imm, udata); | 
|  | } | 
|  |  | 
|  | void qemu_plugin_register_vcpu_tb_exec_inline_per_vcpu( | 
|  | struct qemu_plugin_tb *tb, | 
|  | enum qemu_plugin_op op, | 
|  | qemu_plugin_u64 entry, | 
|  | uint64_t imm) | 
|  | { | 
|  | if (!tb_is_mem_only()) { | 
|  | plugin_register_inline_op_on_entry(&tb->cbs, 0, op, entry, imm); | 
|  | } | 
|  | } | 
|  |  | 
|  | void qemu_plugin_register_vcpu_insn_exec_cb(struct qemu_plugin_insn *insn, | 
|  | qemu_plugin_vcpu_udata_cb_t cb, | 
|  | enum qemu_plugin_cb_flags flags, | 
|  | void *udata) | 
|  | { | 
|  | if (!tb_is_mem_only()) { | 
|  | plugin_register_dyn_cb__udata(&insn->insn_cbs, cb, flags, udata); | 
|  | } | 
|  | } | 
|  |  | 
|  | void qemu_plugin_register_vcpu_insn_exec_cond_cb( | 
|  | struct qemu_plugin_insn *insn, | 
|  | qemu_plugin_vcpu_udata_cb_t cb, | 
|  | enum qemu_plugin_cb_flags flags, | 
|  | enum qemu_plugin_cond cond, | 
|  | qemu_plugin_u64 entry, | 
|  | uint64_t imm, | 
|  | void *udata) | 
|  | { | 
|  | if (cond == QEMU_PLUGIN_COND_NEVER || tb_is_mem_only()) { | 
|  | return; | 
|  | } | 
|  | if (cond == QEMU_PLUGIN_COND_ALWAYS) { | 
|  | qemu_plugin_register_vcpu_insn_exec_cb(insn, cb, flags, udata); | 
|  | return; | 
|  | } | 
|  | plugin_register_dyn_cond_cb__udata(&insn->insn_cbs, cb, flags, | 
|  | cond, entry, imm, udata); | 
|  | } | 
|  |  | 
|  | void qemu_plugin_register_vcpu_insn_exec_inline_per_vcpu( | 
|  | struct qemu_plugin_insn *insn, | 
|  | enum qemu_plugin_op op, | 
|  | qemu_plugin_u64 entry, | 
|  | uint64_t imm) | 
|  | { | 
|  | if (!tb_is_mem_only()) { | 
|  | plugin_register_inline_op_on_entry(&insn->insn_cbs, 0, op, entry, imm); | 
|  | } | 
|  | } | 
|  |  | 
|  |  | 
|  | /* | 
|  | * We always plant memory instrumentation because they don't finalise until | 
|  | * after the operation has complete. | 
|  | */ | 
|  | void qemu_plugin_register_vcpu_mem_cb(struct qemu_plugin_insn *insn, | 
|  | qemu_plugin_vcpu_mem_cb_t cb, | 
|  | enum qemu_plugin_cb_flags flags, | 
|  | enum qemu_plugin_mem_rw rw, | 
|  | void *udata) | 
|  | { | 
|  | plugin_register_vcpu_mem_cb(&insn->mem_cbs, cb, flags, rw, udata); | 
|  | } | 
|  |  | 
|  | void qemu_plugin_register_vcpu_mem_inline_per_vcpu( | 
|  | struct qemu_plugin_insn *insn, | 
|  | enum qemu_plugin_mem_rw rw, | 
|  | enum qemu_plugin_op op, | 
|  | qemu_plugin_u64 entry, | 
|  | uint64_t imm) | 
|  | { | 
|  | plugin_register_inline_op_on_entry(&insn->mem_cbs, rw, op, entry, imm); | 
|  | } | 
|  |  | 
|  | void qemu_plugin_register_vcpu_tb_trans_cb(qemu_plugin_id_t id, | 
|  | qemu_plugin_vcpu_tb_trans_cb_t cb) | 
|  | { | 
|  | plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_TB_TRANS, cb); | 
|  | } | 
|  |  | 
|  | void qemu_plugin_register_vcpu_syscall_cb(qemu_plugin_id_t id, | 
|  | qemu_plugin_vcpu_syscall_cb_t cb) | 
|  | { | 
|  | plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_SYSCALL, cb); | 
|  | } | 
|  |  | 
|  | void | 
|  | qemu_plugin_register_vcpu_syscall_ret_cb(qemu_plugin_id_t id, | 
|  | qemu_plugin_vcpu_syscall_ret_cb_t cb) | 
|  | { | 
|  | plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_SYSCALL_RET, cb); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Plugin Queries | 
|  | * | 
|  | * These are queries that the plugin can make to gauge information | 
|  | * from our opaque data types. We do not want to leak internal details | 
|  | * here just information useful to the plugin. | 
|  | */ | 
|  |  | 
|  | /* | 
|  | * Translation block information: | 
|  | * | 
|  | * A plugin can query the virtual address of the start of the block | 
|  | * and the number of instructions in it. It can also get access to | 
|  | * each translated instruction. | 
|  | */ | 
|  |  | 
|  | size_t qemu_plugin_tb_n_insns(const struct qemu_plugin_tb *tb) | 
|  | { | 
|  | return tb->n; | 
|  | } | 
|  |  | 
|  | uint64_t qemu_plugin_tb_vaddr(const struct qemu_plugin_tb *tb) | 
|  | { | 
|  | const DisasContextBase *db = tcg_ctx->plugin_db; | 
|  | return db->pc_first; | 
|  | } | 
|  |  | 
|  | struct qemu_plugin_insn * | 
|  | qemu_plugin_tb_get_insn(const struct qemu_plugin_tb *tb, size_t idx) | 
|  | { | 
|  | struct qemu_plugin_insn *insn; | 
|  | if (unlikely(idx >= tb->n)) { | 
|  | return NULL; | 
|  | } | 
|  | insn = g_ptr_array_index(tb->insns, idx); | 
|  | return insn; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Instruction information | 
|  | * | 
|  | * These queries allow the plugin to retrieve information about each | 
|  | * instruction being translated. | 
|  | */ | 
|  |  | 
|  | size_t qemu_plugin_insn_data(const struct qemu_plugin_insn *insn, | 
|  | void *dest, size_t len) | 
|  | { | 
|  | const DisasContextBase *db = tcg_ctx->plugin_db; | 
|  |  | 
|  | len = MIN(len, insn->len); | 
|  | return translator_st(db, dest, insn->vaddr, len) ? len : 0; | 
|  | } | 
|  |  | 
|  | size_t qemu_plugin_insn_size(const struct qemu_plugin_insn *insn) | 
|  | { | 
|  | return insn->len; | 
|  | } | 
|  |  | 
|  | uint64_t qemu_plugin_insn_vaddr(const struct qemu_plugin_insn *insn) | 
|  | { | 
|  | return insn->vaddr; | 
|  | } | 
|  |  | 
|  | void *qemu_plugin_insn_haddr(const struct qemu_plugin_insn *insn) | 
|  | { | 
|  | const DisasContextBase *db = tcg_ctx->plugin_db; | 
|  | vaddr page0_last = db->pc_first | ~TARGET_PAGE_MASK; | 
|  |  | 
|  | if (db->fake_insn) { | 
|  | return NULL; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * ??? The return value is not intended for use of host memory, | 
|  | * but as a proxy for address space and physical address. | 
|  | * Thus we are only interested in the first byte and do not | 
|  | * care about spanning pages. | 
|  | */ | 
|  | if (insn->vaddr <= page0_last) { | 
|  | if (db->host_addr[0] == NULL) { | 
|  | return NULL; | 
|  | } | 
|  | return db->host_addr[0] + insn->vaddr - db->pc_first; | 
|  | } else { | 
|  | if (db->host_addr[1] == NULL) { | 
|  | return NULL; | 
|  | } | 
|  | return db->host_addr[1] + insn->vaddr - (page0_last + 1); | 
|  | } | 
|  | } | 
|  |  | 
|  | char *qemu_plugin_insn_disas(const struct qemu_plugin_insn *insn) | 
|  | { | 
|  | return plugin_disas(tcg_ctx->cpu, tcg_ctx->plugin_db, | 
|  | insn->vaddr, insn->len); | 
|  | } | 
|  |  | 
|  | const char *qemu_plugin_insn_symbol(const struct qemu_plugin_insn *insn) | 
|  | { | 
|  | const char *sym = lookup_symbol(insn->vaddr); | 
|  | return sym[0] != 0 ? sym : NULL; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * The memory queries allow the plugin to query information about a | 
|  | * memory access. | 
|  | */ | 
|  |  | 
|  | unsigned qemu_plugin_mem_size_shift(qemu_plugin_meminfo_t info) | 
|  | { | 
|  | MemOp op = get_memop(info); | 
|  | return op & MO_SIZE; | 
|  | } | 
|  |  | 
|  | bool qemu_plugin_mem_is_sign_extended(qemu_plugin_meminfo_t info) | 
|  | { | 
|  | MemOp op = get_memop(info); | 
|  | return op & MO_SIGN; | 
|  | } | 
|  |  | 
|  | bool qemu_plugin_mem_is_big_endian(qemu_plugin_meminfo_t info) | 
|  | { | 
|  | MemOp op = get_memop(info); | 
|  | return (op & MO_BSWAP) == MO_BE; | 
|  | } | 
|  |  | 
|  | bool qemu_plugin_mem_is_store(qemu_plugin_meminfo_t info) | 
|  | { | 
|  | return get_plugin_meminfo_rw(info) & QEMU_PLUGIN_MEM_W; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Virtual Memory queries | 
|  | */ | 
|  |  | 
|  | #ifdef CONFIG_SOFTMMU | 
|  | static __thread struct qemu_plugin_hwaddr hwaddr_info; | 
|  | #endif | 
|  |  | 
|  | struct qemu_plugin_hwaddr *qemu_plugin_get_hwaddr(qemu_plugin_meminfo_t info, | 
|  | uint64_t vaddr) | 
|  | { | 
|  | #ifdef CONFIG_SOFTMMU | 
|  | CPUState *cpu = current_cpu; | 
|  | unsigned int mmu_idx = get_mmuidx(info); | 
|  | enum qemu_plugin_mem_rw rw = get_plugin_meminfo_rw(info); | 
|  | hwaddr_info.is_store = (rw & QEMU_PLUGIN_MEM_W) != 0; | 
|  |  | 
|  | assert(mmu_idx < NB_MMU_MODES); | 
|  |  | 
|  | if (!tlb_plugin_lookup(cpu, vaddr, mmu_idx, | 
|  | hwaddr_info.is_store, &hwaddr_info)) { | 
|  | error_report("invalid use of qemu_plugin_get_hwaddr"); | 
|  | return NULL; | 
|  | } | 
|  |  | 
|  | return &hwaddr_info; | 
|  | #else | 
|  | return NULL; | 
|  | #endif | 
|  | } | 
|  |  | 
|  | bool qemu_plugin_hwaddr_is_io(const struct qemu_plugin_hwaddr *haddr) | 
|  | { | 
|  | #ifdef CONFIG_SOFTMMU | 
|  | return haddr->is_io; | 
|  | #else | 
|  | return false; | 
|  | #endif | 
|  | } | 
|  |  | 
|  | uint64_t qemu_plugin_hwaddr_phys_addr(const struct qemu_plugin_hwaddr *haddr) | 
|  | { | 
|  | #ifdef CONFIG_SOFTMMU | 
|  | if (haddr) { | 
|  | return haddr->phys_addr; | 
|  | } | 
|  | #endif | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | const char *qemu_plugin_hwaddr_device_name(const struct qemu_plugin_hwaddr *h) | 
|  | { | 
|  | #ifdef CONFIG_SOFTMMU | 
|  | if (h && h->is_io) { | 
|  | MemoryRegion *mr = h->mr; | 
|  | if (!mr->name) { | 
|  | unsigned maddr = (uintptr_t)mr; | 
|  | g_autofree char *temp = g_strdup_printf("anon%08x", maddr); | 
|  | return g_intern_string(temp); | 
|  | } else { | 
|  | return g_intern_string(mr->name); | 
|  | } | 
|  | } else { | 
|  | return g_intern_static_string("RAM"); | 
|  | } | 
|  | #else | 
|  | return g_intern_static_string("Invalid"); | 
|  | #endif | 
|  | } | 
|  |  | 
|  | int qemu_plugin_num_vcpus(void) | 
|  | { | 
|  | return plugin_num_vcpus(); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Plugin output | 
|  | */ | 
|  | void qemu_plugin_outs(const char *string) | 
|  | { | 
|  | qemu_log_mask(CPU_LOG_PLUGIN, "%s", string); | 
|  | } | 
|  |  | 
|  | bool qemu_plugin_bool_parse(const char *name, const char *value, bool *ret) | 
|  | { | 
|  | return name && value && qapi_bool_parse(name, value, ret, NULL); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Binary path, start and end locations | 
|  | */ | 
|  | const char *qemu_plugin_path_to_binary(void) | 
|  | { | 
|  | char *path = NULL; | 
|  | #ifdef CONFIG_USER_ONLY | 
|  | TaskState *ts = get_task_state(current_cpu); | 
|  | path = g_strdup(ts->bprm->filename); | 
|  | #endif | 
|  | return path; | 
|  | } | 
|  |  | 
|  | uint64_t qemu_plugin_start_code(void) | 
|  | { | 
|  | uint64_t start = 0; | 
|  | #ifdef CONFIG_USER_ONLY | 
|  | TaskState *ts = get_task_state(current_cpu); | 
|  | start = ts->info->start_code; | 
|  | #endif | 
|  | return start; | 
|  | } | 
|  |  | 
|  | uint64_t qemu_plugin_end_code(void) | 
|  | { | 
|  | uint64_t end = 0; | 
|  | #ifdef CONFIG_USER_ONLY | 
|  | TaskState *ts = get_task_state(current_cpu); | 
|  | end = ts->info->end_code; | 
|  | #endif | 
|  | return end; | 
|  | } | 
|  |  | 
|  | uint64_t qemu_plugin_entry_code(void) | 
|  | { | 
|  | uint64_t entry = 0; | 
|  | #ifdef CONFIG_USER_ONLY | 
|  | TaskState *ts = get_task_state(current_cpu); | 
|  | entry = ts->info->entry; | 
|  | #endif | 
|  | return entry; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Create register handles. | 
|  | * | 
|  | * We need to create a handle for each register so the plugin | 
|  | * infrastructure can call gdbstub to read a register. They are | 
|  | * currently just a pointer encapsulation of the gdb_reg but in | 
|  | * future may hold internal plugin state so its important plugin | 
|  | * authors are not tempted to treat them as numbers. | 
|  | * | 
|  | * We also construct a result array with those handles and some | 
|  | * ancillary data the plugin might find useful. | 
|  | */ | 
|  |  | 
|  | static GArray *create_register_handles(GArray *gdbstub_regs) | 
|  | { | 
|  | GArray *find_data = g_array_new(true, true, | 
|  | sizeof(qemu_plugin_reg_descriptor)); | 
|  |  | 
|  | for (int i = 0; i < gdbstub_regs->len; i++) { | 
|  | GDBRegDesc *grd = &g_array_index(gdbstub_regs, GDBRegDesc, i); | 
|  | qemu_plugin_reg_descriptor desc; | 
|  |  | 
|  | /* skip "un-named" regs */ | 
|  | if (!grd->name) { | 
|  | continue; | 
|  | } | 
|  |  | 
|  | /* Create a record for the plugin */ | 
|  | desc.handle = GINT_TO_POINTER(grd->gdb_reg); | 
|  | desc.name = g_intern_string(grd->name); | 
|  | desc.feature = g_intern_string(grd->feature_name); | 
|  | g_array_append_val(find_data, desc); | 
|  | } | 
|  |  | 
|  | return find_data; | 
|  | } | 
|  |  | 
|  | GArray *qemu_plugin_get_registers(void) | 
|  | { | 
|  | g_assert(current_cpu); | 
|  |  | 
|  | g_autoptr(GArray) regs = gdb_get_register_list(current_cpu); | 
|  | return create_register_handles(regs); | 
|  | } | 
|  |  | 
|  | int qemu_plugin_read_register(struct qemu_plugin_register *reg, GByteArray *buf) | 
|  | { | 
|  | g_assert(current_cpu); | 
|  |  | 
|  | return gdb_read_register(current_cpu, buf, GPOINTER_TO_INT(reg)); | 
|  | } | 
|  |  | 
|  | struct qemu_plugin_scoreboard *qemu_plugin_scoreboard_new(size_t element_size) | 
|  | { | 
|  | return plugin_scoreboard_new(element_size); | 
|  | } | 
|  |  | 
|  | void qemu_plugin_scoreboard_free(struct qemu_plugin_scoreboard *score) | 
|  | { | 
|  | plugin_scoreboard_free(score); | 
|  | } | 
|  |  | 
|  | void *qemu_plugin_scoreboard_find(struct qemu_plugin_scoreboard *score, | 
|  | unsigned int vcpu_index) | 
|  | { | 
|  | g_assert(vcpu_index < qemu_plugin_num_vcpus()); | 
|  | /* we can't use g_array_index since entry size is not statically known */ | 
|  | char *base_ptr = score->data->data; | 
|  | return base_ptr + vcpu_index * g_array_get_element_size(score->data); | 
|  | } | 
|  |  | 
|  | static uint64_t *plugin_u64_address(qemu_plugin_u64 entry, | 
|  | unsigned int vcpu_index) | 
|  | { | 
|  | char *ptr = qemu_plugin_scoreboard_find(entry.score, vcpu_index); | 
|  | return (uint64_t *)(ptr + entry.offset); | 
|  | } | 
|  |  | 
|  | void qemu_plugin_u64_add(qemu_plugin_u64 entry, unsigned int vcpu_index, | 
|  | uint64_t added) | 
|  | { | 
|  | *plugin_u64_address(entry, vcpu_index) += added; | 
|  | } | 
|  |  | 
|  | uint64_t qemu_plugin_u64_get(qemu_plugin_u64 entry, | 
|  | unsigned int vcpu_index) | 
|  | { | 
|  | return *plugin_u64_address(entry, vcpu_index); | 
|  | } | 
|  |  | 
|  | void qemu_plugin_u64_set(qemu_plugin_u64 entry, unsigned int vcpu_index, | 
|  | uint64_t val) | 
|  | { | 
|  | *plugin_u64_address(entry, vcpu_index) = val; | 
|  | } | 
|  |  | 
|  | uint64_t qemu_plugin_u64_sum(qemu_plugin_u64 entry) | 
|  | { | 
|  | uint64_t total = 0; | 
|  | for (int i = 0, n = qemu_plugin_num_vcpus(); i < n; ++i) { | 
|  | total += qemu_plugin_u64_get(entry, i); | 
|  | } | 
|  | return total; | 
|  | } |