@@ -6,3 +6,4 @@ obj-y += translator.o
obj-$(CONFIG_USER_ONLY) += user-exec.o
obj-$(call lnot,$(CONFIG_SOFTMMU)) += user-exec-stub.o
+obj-$(CONFIG_PLUGIN) += plugin-gen.o
new file mode 100644
@@ -0,0 +1,1072 @@
+/*
+ * plugin-gen.c - TCG-related bits of plugin infrastructure
+ *
+ * Copyright (C) 2018, Emilio G. Cota <cota@braap.org>
+ * License: GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ * We support instrumentation at an instruction granularity. That is,
+ * if a plugin wants to instrument the memory accesses performed by a
+ * particular instruction, it can just do that instead of instrumenting
+ * all memory accesses. Thus, in order to do this we first have to
+ * translate a TB, so that plugins can decide what/where to instrument.
+ *
+ * Injecting the desired instrumentation could be done with a second
+ * translation pass that combined the instrumentation requests, but that
+ * would be ugly and inefficient since we would decode the guest code twice.
+ * Instead, during TB translation we add "empty" instrumentation calls for all
+ * possible instrumentation events, and then once we collect the instrumentation
+ * requests from plugins, we either "fill in" those empty events or remove them
+ * if they have no requests.
+ *
+ * When "filling in" an event we first copy the empty callback's TCG ops. This
+ * might seem unnecessary, but it is done to support an arbitrary number
+ * of callbacks per event. Take for example a regular instruction callback.
+ * We first generate a callback to an empty helper function. Then, if two
+ * plugins register one callback each for this instruction, we make two copies
+ * of the TCG ops generated for the empty callback, substituting the function
+ * pointer that points to the empty helper function with the plugins' desired
+ * callback functions. After that we remove the empty callback's ops.
+ *
+ * Note that the location in TCGOp.args[] of the pointer to a helper function
+ * varies across different guest and host architectures. Instead of duplicating
+ * the logic that figures this out, we rely on the fact that the empty
+ * callbacks point to empty functions that are unique pointers in the program.
+ * Thus, to find the right location we just have to look for a match in
+ * TCGOp.args[]. This is the main reason why we first copy an empty callback's
+ * TCG ops and then fill them in; regardless of whether we have one or many
+ * callbacks for that event, the logic to add all of them is the same.
+ *
+ * When generating more than one callback per event, we make a small
+ * optimization to avoid generating redundant operations. For instance, for the
+ * second and all subsequent callbacks of an event, we do not need to reload the
+ * CPU's index into a TCG temp, since the first callback did it already.
+ */
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "tcg/tcg.h"
+#include "tcg/tcg-op.h"
+#include "trace/mem.h"
+#include "exec/exec-all.h"
+#include "exec/plugin-gen.h"
+#include "exec/translator.h"
+
+#ifdef CONFIG_SOFTMMU
+# define CONFIG_SOFTMMU_GATE 1
+#else
+# define CONFIG_SOFTMMU_GATE 0
+#endif
+
+/*
+ * plugin_cb_start TCG op args[]:
+ * 0: enum plugin_gen_from
+ * 1: enum plugin_gen_cb (defined below)
+ * 2: set to 1 if it's a mem callback and it's a write, 0 otherwise.
+ */
+enum plugin_gen_cb {
+ PLUGIN_GEN_CB_UDATA,
+ PLUGIN_GEN_CB_INLINE,
+ PLUGIN_GEN_CB_MEM,
+ PLUGIN_GEN_CB_HADDR,
+ PLUGIN_GEN_ENABLE_MEM_HELPER,
+ PLUGIN_GEN_DISABLE_MEM_HELPER,
+ PLUGIN_GEN_N_CBS,
+};
+
+void HELPER(plugin_vcpu_udata_cb)(uint32_t cpu_index, void *udata)
+{ }
+
+void HELPER(plugin_vcpu_mem_cb)(unsigned int vcpu_index,
+ qemu_plugin_meminfo_t info, uint64_t vaddr,
+ void *userdata)
+{ }
+
+void HELPER(plugin_vcpu_mem_haddr_cb)(unsigned int vcpu_index,
+ qemu_plugin_meminfo_t info,
+ uint64_t vaddr, void *haddr,
+ void *userdata)
+{ }
+
+static void do_gen_mem_cb(TCGv vaddr, uint8_t info, bool is_haddr)
+{
+ TCGv_i32 cpu_index = tcg_temp_new_i32();
+ TCGv_i32 meminfo = tcg_const_i32(info);
+ TCGv_i64 vaddr64 = tcg_temp_new_i64();
+ TCGv_ptr udata = tcg_const_ptr(NULL);
+ TCGv_ptr haddr;
+
+ tcg_gen_ld_i32(cpu_index, cpu_env,
+ -ENV_OFFSET + offsetof(CPUState, cpu_index));
+ tcg_gen_extu_tl_i64(vaddr64, vaddr);
+
+ if (is_haddr) {
+ /*
+ * Can't use CONFIG_SOFTMMU_GATE here because CPUArchState.hostaddr
+ * only exists in CONFIG_SOFTMMU.
+ */
+#ifdef CONFIG_SOFTMMU
+ haddr = tcg_temp_new_ptr();
+ tcg_gen_ld_ptr(haddr, cpu_env, offsetof(CPUArchState, hostaddr));
+#else
+ haddr = tcg_const_ptr(NULL);
+#endif
+ gen_helper_plugin_vcpu_mem_haddr_cb(cpu_index, meminfo, vaddr64,
+ haddr, udata);
+ tcg_temp_free_ptr(haddr);
+ } else {
+ gen_helper_plugin_vcpu_mem_cb(cpu_index, meminfo, vaddr64, udata);
+ }
+
+ tcg_temp_free_ptr(udata);
+ tcg_temp_free_i64(vaddr64);
+ tcg_temp_free_i32(meminfo);
+ tcg_temp_free_i32(cpu_index);
+}
+
+static void gen_empty_udata_cb(void)
+{
+ TCGv_i32 cpu_index = tcg_temp_new_i32();
+ TCGv_ptr udata = tcg_const_ptr(NULL); /* will be overwritten later */
+
+ tcg_gen_ld_i32(cpu_index, cpu_env,
+ -ENV_OFFSET + offsetof(CPUState, cpu_index));
+ gen_helper_plugin_vcpu_udata_cb(cpu_index, udata);
+
+ tcg_temp_free_ptr(udata);
+ tcg_temp_free_i32(cpu_index);
+}
+
+/*
+ * For now we only support addi_i64.
+ * When we support more ops, we can generate one empty inline cb for each.
+ */
+static void gen_empty_inline_cb(void)
+{
+ TCGv_i64 val = tcg_temp_new_i64();
+ TCGv_ptr ptr = tcg_const_ptr(NULL); /* overwritten later */
+
+ tcg_gen_ld_i64(val, ptr, 0);
+ /* pass an immediate != 0 so that it doesn't get optimized away */
+ tcg_gen_addi_i64(val, val, 0xdeadface);
+ tcg_gen_st_i64(val, ptr, 0);
+ tcg_temp_free_ptr(ptr);
+ tcg_temp_free_i64(val);
+}
+
+static void gen_empty_mem_cb(TCGv addr, uint8_t info)
+{
+ do_gen_mem_cb(addr, info, false);
+}
+
+static void gen_empty_haddr_cb(TCGv addr, uint8_t info)
+{
+ do_gen_mem_cb(addr, info, true);
+}
+
+/*
+ * Share the same function for enable/disable. When enabling, the NULL
+ * pointer will be overwritten later.
+ */
+static void gen_empty_mem_helper(void)
+{
+ TCGv_ptr ptr;
+
+ ptr = tcg_const_ptr(NULL);
+ tcg_gen_st_ptr(ptr, cpu_env, -ENV_OFFSET + offsetof(CPUState,
+ plugin_mem_cbs));
+ tcg_temp_free_ptr(ptr);
+}
+
+static inline
+void gen_plugin_cb_start(enum plugin_gen_from from,
+ enum plugin_gen_cb type, unsigned wr)
+{
+ TCGOp *op;
+
+ tcg_gen_plugin_cb_start(from, type, wr);
+ op = tcg_last_op();
+ QSIMPLEQ_INSERT_TAIL(&tcg_ctx->plugin_ops, op, plugin_link);
+}
+
+static void gen_wrapped(enum plugin_gen_from from,
+ enum plugin_gen_cb type, void (*func)(void))
+{
+ gen_plugin_cb_start(from, type, 0);
+ func();
+ tcg_gen_plugin_cb_end();
+}
+
+static inline void plugin_gen_empty_callback(enum plugin_gen_from from)
+{
+ switch (from) {
+ case PLUGIN_GEN_AFTER_INSN:
+ gen_wrapped(from, PLUGIN_GEN_DISABLE_MEM_HELPER,
+ gen_empty_mem_helper);
+ break;
+ case PLUGIN_GEN_FROM_INSN:
+ /*
+ * Note: plugin_gen_inject() relies on ENABLE_MEM_HELPER being
+ * the first callback of an instruction
+ */
+ gen_wrapped(from, PLUGIN_GEN_ENABLE_MEM_HELPER,
+ gen_empty_mem_helper);
+ /* fall through */
+ case PLUGIN_GEN_FROM_TB:
+ gen_wrapped(from, PLUGIN_GEN_CB_UDATA, gen_empty_udata_cb);
+ gen_wrapped(from, PLUGIN_GEN_CB_INLINE, gen_empty_inline_cb);
+ break;
+ default:
+ g_assert_not_reached();
+ }
+}
+
+union mem_gen_fn {
+ void (*mem_fn)(TCGv, uint8_t);
+ void (*inline_fn)(void);
+};
+
+static void gen_mem_wrapped(enum plugin_gen_cb type,
+ const union mem_gen_fn *f, TCGv addr,
+ uint8_t info, bool is_mem)
+{
+ int wr = !!(info & TRACE_MEM_ST);
+
+ gen_plugin_cb_start(PLUGIN_GEN_FROM_MEM, type, wr);
+ if (is_mem) {
+ f->mem_fn(addr, info);
+ } else {
+ f->inline_fn();
+ }
+ tcg_gen_plugin_cb_end();
+}
+
+void plugin_gen_empty_mem_callback(TCGv addr, uint8_t info)
+{
+ union mem_gen_fn fn;
+
+ fn.mem_fn = gen_empty_mem_cb;
+ gen_mem_wrapped(PLUGIN_GEN_CB_MEM, &fn, addr, info, true);
+
+ fn.mem_fn = gen_empty_haddr_cb;
+ gen_mem_wrapped(PLUGIN_GEN_CB_HADDR, &fn, addr, info, true);
+
+ fn.inline_fn = gen_empty_inline_cb;
+ gen_mem_wrapped(PLUGIN_GEN_CB_INLINE, &fn, 0, info, false);
+}
+
+static TCGOp *find_op(TCGOp *op, TCGOpcode opc)
+{
+ while (op) {
+ if (op->opc == opc) {
+ return op;
+ }
+ op = QTAILQ_NEXT(op, link);
+ }
+ return NULL;
+}
+
+static TCGOp *rm_ops_range(TCGOp *begin, TCGOp *end)
+{
+ TCGOp *ret = QTAILQ_NEXT(end, link);
+
+ QTAILQ_REMOVE_SEVERAL(&tcg_ctx->ops, begin, end, link);
+ return ret;
+}
+
+/* remove all ops until (and including) plugin_cb_end */
+static TCGOp *rm_ops(TCGOp *op)
+{
+ TCGOp *end_op = find_op(op, INDEX_op_plugin_cb_end);
+
+ tcg_debug_assert(end_op);
+ return rm_ops_range(op, end_op);
+}
+
+static TCGOp *copy_op_nocheck(TCGOp **begin_op, TCGOp *op)
+{
+ *begin_op = QTAILQ_NEXT(*begin_op, link);
+ tcg_debug_assert(*begin_op);
+ op = tcg_op_insert_after(tcg_ctx, op, (*begin_op)->opc);
+ memcpy(op->args, (*begin_op)->args, sizeof(op->args));
+ return op;
+}
+
+static TCGOp *copy_op(TCGOp **begin_op, TCGOp *op, TCGOpcode opc)
+{
+ op = copy_op_nocheck(begin_op, op);
+ tcg_debug_assert((*begin_op)->opc == opc);
+ return op;
+}
+
+static TCGOp *copy_extu_i32_i64(TCGOp **begin_op, TCGOp *op)
+{
+ if (TCG_TARGET_REG_BITS == 32) {
+ /* mov_i32 */
+ op = copy_op(begin_op, op, INDEX_op_mov_i32);
+ /* movi_i32 */
+ op = copy_op(begin_op, op, INDEX_op_movi_i32);
+ } else {
+ /* extu_i32_i64 */
+ op = copy_op(begin_op, op, INDEX_op_extu_i32_i64);
+ }
+ return op;
+}
+
+static TCGOp *copy_mov_i64(TCGOp **begin_op, TCGOp *op)
+{
+ if (TCG_TARGET_REG_BITS == 32) {
+ /* 2x mov_i32 */
+ op = copy_op(begin_op, op, INDEX_op_mov_i32);
+ op = copy_op(begin_op, op, INDEX_op_mov_i32);
+ } else {
+ /* mov_i64 */
+ op = copy_op(begin_op, op, INDEX_op_mov_i64);
+ }
+ return op;
+}
+
+static TCGOp *copy_movi_i64(TCGOp **begin_op, TCGOp *op, uint64_t v)
+{
+ if (TCG_TARGET_REG_BITS == 32) {
+ /* 2x movi_i32 */
+ op = copy_op(begin_op, op, INDEX_op_movi_i32);
+ op->args[1] = v;
+
+ op = copy_op(begin_op, op, INDEX_op_movi_i32);
+ op->args[1] = v >> 32;
+ } else {
+ /* movi_i64 */
+ op = copy_op(begin_op, op, INDEX_op_movi_i64);
+ op->args[1] = v;
+ }
+ return op;
+}
+
+static TCGOp *copy_const_ptr(TCGOp **begin_op, TCGOp *op, void *ptr)
+{
+ if (UINTPTR_MAX == UINT32_MAX) {
+ /* movi_i32 */
+ op = copy_op(begin_op, op, INDEX_op_movi_i32);
+ op->args[1] = (uintptr_t)ptr;
+ } else {
+ /* movi_i64 */
+ op = copy_movi_i64(begin_op, op, (uint64_t)(uintptr_t)ptr);
+ }
+ return op;
+}
+
+static TCGOp *copy_const_i64(TCGOp **begin_op, TCGOp *op, uint64_t v)
+{
+ return copy_movi_i64(begin_op, op, v);
+}
+
+static TCGOp *copy_extu_tl_i64(TCGOp **begin_op, TCGOp *op)
+{
+ if (TARGET_LONG_BITS == 32) {
+ /* extu_i32_i64 */
+ op = copy_extu_i32_i64(begin_op, op);
+ } else {
+ /* mov_i64 */
+ op = copy_mov_i64(begin_op, op);
+ }
+ return op;
+}
+
+static TCGOp *copy_ld_i64(TCGOp **begin_op, TCGOp *op)
+{
+ if (TCG_TARGET_REG_BITS == 32) {
+ /* 2x ld_i32 */
+ op = copy_op(begin_op, op, INDEX_op_ld_i32);
+ op = copy_op(begin_op, op, INDEX_op_ld_i32);
+ } else {
+ /* ld_i64 */
+ op = copy_op(begin_op, op, INDEX_op_ld_i64);
+ }
+ return op;
+}
+
+static TCGOp *copy_ld_ptr(TCGOp **begin_op, TCGOp *op)
+{
+ if (UINTPTR_MAX == UINT32_MAX) {
+ /* ld_i32 */
+ op = copy_op(begin_op, op, INDEX_op_ld_i32);
+ } else {
+ /* ld_i64 */
+ op = copy_ld_i64(begin_op, op);
+ }
+ return op;
+}
+
+static TCGOp *skip_ld_i64(TCGOp *begin_op)
+{
+ TCGOp *op;
+
+ if (TCG_TARGET_REG_BITS == 32) {
+ /* 2x ld_i32 */
+ op = QTAILQ_NEXT(begin_op, link);
+ tcg_debug_assert(op->opc == INDEX_op_ld_i32);
+ op = QTAILQ_NEXT(op, link);
+ tcg_debug_assert(op->opc == INDEX_op_ld_i32);
+ } else {
+ /* ld_i64 */
+ op = QTAILQ_NEXT(begin_op, link);
+ tcg_debug_assert(op->opc == INDEX_op_ld_i64);
+ }
+ return op;
+}
+
+static TCGOp *skip_ld_ptr(TCGOp *begin_op)
+{
+ TCGOp *op;
+
+ if (UINTPTR_MAX == UINT32_MAX) {
+ /* ld_i32 */
+ op = QTAILQ_NEXT(begin_op, link);
+ tcg_debug_assert(op->opc == INDEX_op_ld_i32);
+ } else {
+ /* ld_i64 */
+ op = skip_ld_i64(begin_op);
+ }
+ return op;
+}
+
+static TCGOp *copy_st_i64(TCGOp **begin_op, TCGOp *op)
+{
+ if (TCG_TARGET_REG_BITS == 32) {
+ /* 2x st_i32 */
+ op = copy_op(begin_op, op, INDEX_op_st_i32);
+ op = copy_op(begin_op, op, INDEX_op_st_i32);
+ } else {
+ /* st_i64 */
+ op = copy_op(begin_op, op, INDEX_op_st_i64);
+ }
+ return op;
+}
+
+static TCGOp *copy_add_i64(TCGOp **begin_op, TCGOp *op)
+{
+ if (TCG_TARGET_REG_BITS == 32) {
+ /* all 32-bit backends must implement add2_i32 */
+ g_assert(TCG_TARGET_HAS_add2_i32);
+ op = copy_op(begin_op, op, INDEX_op_add2_i32);
+ } else {
+ op = copy_op(begin_op, op, INDEX_op_add_i64);
+ }
+ return op;
+}
+
+static TCGOp *copy_st_ptr(TCGOp **begin_op, TCGOp *op)
+{
+ if (UINTPTR_MAX == UINT32_MAX) {
+ /* st_i32 */
+ op = copy_op(begin_op, op, INDEX_op_st_i32);
+ } else {
+ /* st_i64 */
+ op = copy_st_i64(begin_op, op);
+ }
+ return op;
+}
+
+static TCGOp *copy_call(TCGOp **begin_op, TCGOp *op, void *empty_func,
+ void *func, unsigned tcg_flags, int *cb_idx)
+{
+ /* copy all ops until the call */
+ do {
+ op = copy_op_nocheck(begin_op, op);
+ } while (op->opc != INDEX_op_call);
+
+ /* fill in the op call */
+ op->param1 = (*begin_op)->param1;
+ op->param2 = (*begin_op)->param2;
+ tcg_debug_assert(op->life == 0);
+ if (*cb_idx == -1) {
+ int i;
+
+ /*
+ * Instead of working out the position of the callback in args[], just
+ * look for @empty_func, since it should be a unique pointer.
+ */
+ for (i = 0; i < MAX_OPC_PARAM_ARGS; i++) {
+ if ((uintptr_t)(*begin_op)->args[i] == (uintptr_t)empty_func) {
+ *cb_idx = i;
+ break;
+ }
+ }
+ tcg_debug_assert(i < MAX_OPC_PARAM_ARGS);
+ }
+ op->args[*cb_idx] = (uintptr_t)func;
+ op->args[*cb_idx + 1] = tcg_flags;
+
+ return op;
+}
+
+static TCGOp *append_udata_cb(const struct qemu_plugin_dyn_cb *cb,
+ TCGOp *begin_op, TCGOp *op, int *cb_idx)
+{
+ /* const_ptr */
+ op = copy_const_ptr(&begin_op, op, cb->userp);
+
+ /* copy the ld_i32, but note that we only have to copy it once */
+ begin_op = QTAILQ_NEXT(begin_op, link);
+ tcg_debug_assert(begin_op && begin_op->opc == INDEX_op_ld_i32);
+ if (*cb_idx == -1) {
+ op = tcg_op_insert_after(tcg_ctx, op, INDEX_op_ld_i32);
+ memcpy(op->args, begin_op->args, sizeof(op->args));
+ }
+
+ /* call */
+ op = copy_call(&begin_op, op, HELPER(plugin_vcpu_udata_cb),
+ cb->f.vcpu_udata, cb->tcg_flags, cb_idx);
+
+ return op;
+}
+
+static TCGOp *append_inline_cb(const struct qemu_plugin_dyn_cb *cb,
+ TCGOp *begin_op, TCGOp *op,
+ int *unused)
+{
+ /* const_ptr */
+ op = copy_const_ptr(&begin_op, op, cb->userp);
+
+ /* ld_i64 */
+ op = copy_ld_i64(&begin_op, op);
+
+ /* const_i64 */
+ op = copy_const_i64(&begin_op, op, cb->inline_insn.imm);
+
+ /* add_i64 */
+ op = copy_add_i64(&begin_op, op);
+
+ /* st_i64 */
+ op = copy_st_i64(&begin_op, op);
+
+ return op;
+}
+
+static void set_memop_haddr_ldst_i32(TCGOp *op)
+{
+ int idx;
+
+ if (TARGET_LONG_BITS == 32) {
+ idx = 2;
+ } else {
+ idx = TCG_TARGET_REG_BITS == 32 ? 3 : 2;
+ }
+ op->args[idx] |= make_memop_idx(MO_HADDR, 0);
+}
+
+static void set_memop_haddr_ldst_i64(TCGOp *op)
+{
+ int idx;
+
+ if (TARGET_LONG_BITS == 32) {
+ idx = TCG_TARGET_REG_BITS == 32 ? 3 : 2;
+ } else {
+ idx = TCG_TARGET_REG_BITS == 32 ? 4 : 2;
+ }
+ op->args[idx] |= make_memop_idx(MO_HADDR, 0);
+}
+
+static void find_prev_and_set_memop_haddr(TCGOp *op)
+{
+ while ((op = QTAILQ_PREV(op, link))) {
+ switch (op->opc) {
+ case INDEX_op_qemu_ld_i32:
+ case INDEX_op_qemu_st_i32:
+ set_memop_haddr_ldst_i32(op);
+ return;
+ case INDEX_op_qemu_ld_i64:
+ case INDEX_op_qemu_st_i64:
+ set_memop_haddr_ldst_i64(op);
+ return;
+ default:
+ break;
+ }
+ }
+ g_assert_not_reached();
+}
+
+static TCGOp *append_mem_cb(const struct qemu_plugin_dyn_cb *cb,
+ TCGOp *begin_op, TCGOp *op, int *cb_idx)
+{
+ enum plugin_gen_cb type = begin_op->args[1];
+
+ tcg_debug_assert(type == PLUGIN_GEN_CB_MEM || type == PLUGIN_GEN_CB_HADDR);
+
+ /* const_i32 == movi_i32 ("info", so it remains as is) */
+ op = copy_op(&begin_op, op, INDEX_op_movi_i32);
+
+ /* const_ptr */
+ op = copy_const_ptr(&begin_op, op, cb->userp);
+
+ /* copy the ld_i32, but note that we only have to copy it once */
+ begin_op = QTAILQ_NEXT(begin_op, link);
+ tcg_debug_assert(begin_op && begin_op->opc == INDEX_op_ld_i32);
+ if (*cb_idx == -1) {
+ op = tcg_op_insert_after(tcg_ctx, op, INDEX_op_ld_i32);
+ memcpy(op->args, begin_op->args, sizeof(op->args));
+ }
+
+ /* extu_tl_i64 */
+ op = copy_extu_tl_i64(&begin_op, op);
+
+ if (type == PLUGIN_GEN_CB_MEM) {
+ /* call */
+ op = copy_call(&begin_op, op, HELPER(plugin_vcpu_mem_cb),
+ cb->f.vcpu_udata, cb->tcg_flags, cb_idx);
+ } else {
+ if (CONFIG_SOFTMMU_GATE) {
+ /* ld_ptr; note that we only have to copy it once */
+ if (*cb_idx == -1) {
+ op = copy_ld_ptr(&begin_op, op);
+ find_prev_and_set_memop_haddr(begin_op);
+ } else {
+ begin_op = skip_ld_ptr(begin_op);
+ }
+ } else {
+ /* const_ptr; set it to NULL */
+ op = copy_const_ptr(&begin_op, op, NULL);
+ }
+ /* call */
+ op = copy_call(&begin_op, op, HELPER(plugin_vcpu_mem_haddr_cb),
+ cb->f.vcpu_mem_haddr, cb->tcg_flags, cb_idx);
+ }
+
+ return op;
+}
+
+typedef TCGOp *(*inject_fn)(const struct qemu_plugin_dyn_cb *cb,
+ TCGOp *begin_op, TCGOp *op, int *intp);
+typedef bool (*op_ok_fn)(const TCGOp *op, const struct qemu_plugin_dyn_cb *cb);
+
+static bool op_ok(const TCGOp *op, const struct qemu_plugin_dyn_cb *cb)
+{
+ return true;
+}
+
+static bool op_rw(const TCGOp *op, const struct qemu_plugin_dyn_cb *cb)
+{
+ int w;
+
+ w = op->args[2];
+ return !!(cb->rw & (w + 1));
+}
+
+static inline
+void inject_cb_type(const GArray *cbs, TCGOp *begin_op, inject_fn inject,
+ op_ok_fn ok)
+{
+ TCGOp *end_op;
+ TCGOp *op;
+ int cb_idx = -1;
+ int i;
+
+ if (!cbs || cbs->len == 0) {
+ rm_ops(begin_op);
+ return;
+ }
+
+ end_op = find_op(begin_op, INDEX_op_plugin_cb_end);
+ tcg_debug_assert(end_op);
+
+ op = end_op;
+ for (i = 0; i < cbs->len; i++) {
+ struct qemu_plugin_dyn_cb *cb =
+ &g_array_index(cbs, struct qemu_plugin_dyn_cb, i);
+
+ if (!ok(begin_op, cb)) {
+ continue;
+ }
+ op = inject(cb, begin_op, op, &cb_idx);
+ }
+ rm_ops_range(begin_op, end_op);
+}
+
+static void
+inject_udata_cb(const GArray *cbs, TCGOp *begin_op)
+{
+ inject_cb_type(cbs, begin_op, append_udata_cb, op_ok);
+}
+
+static void
+inject_inline_cb(const GArray *cbs, TCGOp *begin_op, op_ok_fn ok)
+{
+ inject_cb_type(cbs, begin_op, append_inline_cb, ok);
+}
+
+static void
+inject_mem_cb(const GArray *cbs, TCGOp *begin_op)
+{
+ inject_cb_type(cbs, begin_op, append_mem_cb, op_rw);
+}
+
+/* we could change the ops in place, but we can reuse more code by copying */
+static void inject_mem_helper(TCGOp *begin_op, GArray *arr)
+{
+ TCGOp *orig_op = begin_op;
+ TCGOp *end_op;
+ TCGOp *op;
+
+ end_op = find_op(begin_op, INDEX_op_plugin_cb_end);
+ tcg_debug_assert(end_op);
+
+ /* const ptr */
+ op = copy_const_ptr(&begin_op, end_op, arr);
+
+ /* st_ptr */
+ op = copy_st_ptr(&begin_op, op);
+
+ rm_ops_range(orig_op, end_op);
+}
+
+/*
+ * Tracking memory accesses performed from helpers requires extra work.
+ * If an instruction is emulated with helpers, we do two things:
+ * (1) copy the CB descriptors, and keep track of it so that they can be
+ * freed later on, and (2) point CPUState.plugin_mem_cbs to the descriptors, so
+ * that we can read them at run-time (i.e. when the helper executes).
+ * This run-time access is performed from qemu_plugin_vcpu_mem_cb.
+ *
+ * Note that plugin_gen_disable_mem_helpers undoes (2). Since it
+ * is possible that the code we generate after the instruction is
+ * dead, we also add checks before generating tb_exit etc.
+ */
+static void inject_mem_enable_helper(struct qemu_plugin_insn *plugin_insn,
+ TCGOp *begin_op)
+{
+ GArray *cbs[3];
+ GArray *arr;
+ size_t n_cbs, i;
+
+ cbs[0] = plugin_insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_REGULAR];
+ cbs[1] = plugin_insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_INLINE];
+ cbs[2] = plugin_insn->cbs[PLUGIN_CB_HADDR][PLUGIN_CB_REGULAR];
+
+ n_cbs = 0;
+ for (i = 0; i < ARRAY_SIZE(cbs); i++) {
+ n_cbs += cbs[i]->len;
+ }
+
+ plugin_insn->mem_helper = plugin_insn->calls_helpers && n_cbs;
+ if (likely(!plugin_insn->mem_helper)) {
+ rm_ops(begin_op);
+ return;
+ }
+
+ arr = g_array_sized_new(false, false,
+ sizeof(struct qemu_plugin_dyn_cb), n_cbs);
+
+ for (i = 0; i < ARRAY_SIZE(cbs); i++) {
+ g_array_append_vals(arr, cbs[i]->data, cbs[i]->len);
+ }
+
+ qemu_plugin_add_dyn_cb_arr(arr);
+ inject_mem_helper(begin_op, arr);
+}
+
+static void inject_mem_disable_helper(struct qemu_plugin_insn *plugin_insn,
+ TCGOp *begin_op)
+{
+ if (likely(!plugin_insn->mem_helper)) {
+ rm_ops(begin_op);
+ return;
+ }
+ inject_mem_helper(begin_op, NULL);
+}
+
+/* called before finishing a TB with exit_tb, goto_tb or goto_ptr */
+void plugin_gen_disable_mem_helpers(void)
+{
+ TCGv_ptr ptr;
+
+ if (likely(tcg_ctx->plugin_insn == NULL ||
+ !tcg_ctx->plugin_insn->mem_helper)) {
+ return;
+ }
+ ptr = tcg_const_ptr(NULL);
+ tcg_gen_st_ptr(ptr, cpu_env, -ENV_OFFSET + offsetof(CPUState,
+ plugin_mem_cbs));
+ tcg_temp_free_ptr(ptr);
+ tcg_ctx->plugin_insn->mem_helper = false;
+}
+
+static void plugin_gen_tb_udata(const struct qemu_plugin_tb *ptb,
+ TCGOp *begin_op)
+{
+ inject_udata_cb(ptb->cbs[PLUGIN_CB_REGULAR], begin_op);
+}
+
+static void plugin_gen_tb_inline(const struct qemu_plugin_tb *ptb,
+ TCGOp *begin_op)
+{
+ inject_inline_cb(ptb->cbs[PLUGIN_CB_INLINE], begin_op, op_ok);
+}
+
+static void plugin_gen_insn_udata(const struct qemu_plugin_tb *ptb,
+ TCGOp *begin_op, int insn_idx)
+{
+ struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
+
+ inject_udata_cb(insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_REGULAR], begin_op);
+}
+
+static void plugin_gen_insn_inline(const struct qemu_plugin_tb *ptb,
+ TCGOp *begin_op, int insn_idx)
+{
+ struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
+ inject_inline_cb(insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_INLINE],
+ begin_op, op_ok);
+}
+
+static void plugin_gen_mem_regular(const struct qemu_plugin_tb *ptb,
+ TCGOp *begin_op, int insn_idx)
+{
+ struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
+ inject_mem_cb(insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_REGULAR], begin_op);
+}
+
+static void plugin_gen_mem_inline(const struct qemu_plugin_tb *ptb,
+ TCGOp *begin_op, int insn_idx)
+{
+ const GArray *cbs;
+ struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
+
+ cbs = insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_INLINE];
+ inject_inline_cb(cbs, begin_op, op_rw);
+}
+
+static void plugin_gen_haddr_regular(const struct qemu_plugin_tb *ptb,
+ TCGOp *begin_op, int insn_idx)
+{
+ const GArray *cbs;
+ struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
+
+ cbs = insn->cbs[PLUGIN_CB_HADDR][PLUGIN_CB_REGULAR];
+ inject_mem_cb(cbs, begin_op);
+}
+
+static void plugin_gen_enable_mem_helper(const struct qemu_plugin_tb *ptb,
+ TCGOp *begin_op, int insn_idx)
+{
+ struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
+ inject_mem_enable_helper(insn, begin_op);
+}
+
+static void plugin_gen_disable_mem_helper(const struct qemu_plugin_tb *ptb,
+ TCGOp *begin_op, int insn_idx)
+{
+ struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
+ inject_mem_disable_helper(insn, begin_op);
+}
+
+static void plugin_inject_cb(const struct qemu_plugin_tb *ptb, TCGOp *begin_op,
+ int insn_idx)
+{
+ enum plugin_gen_from from = begin_op->args[0];
+ enum plugin_gen_cb type = begin_op->args[1];
+
+ switch (from) {
+ case PLUGIN_GEN_FROM_TB:
+ switch (type) {
+ case PLUGIN_GEN_CB_UDATA:
+ plugin_gen_tb_udata(ptb, begin_op);
+ return;
+ case PLUGIN_GEN_CB_INLINE:
+ plugin_gen_tb_inline(ptb, begin_op);
+ return;
+ default:
+ g_assert_not_reached();
+ }
+ case PLUGIN_GEN_FROM_INSN:
+ switch (type) {
+ case PLUGIN_GEN_CB_UDATA:
+ plugin_gen_insn_udata(ptb, begin_op, insn_idx);
+ return;
+ case PLUGIN_GEN_CB_INLINE:
+ plugin_gen_insn_inline(ptb, begin_op, insn_idx);
+ return;
+ case PLUGIN_GEN_ENABLE_MEM_HELPER:
+ plugin_gen_enable_mem_helper(ptb, begin_op, insn_idx);
+ return;
+ default:
+ g_assert_not_reached();
+ }
+ case PLUGIN_GEN_FROM_MEM:
+ switch (type) {
+ case PLUGIN_GEN_CB_MEM:
+ plugin_gen_mem_regular(ptb, begin_op, insn_idx);
+ return;
+ case PLUGIN_GEN_CB_INLINE:
+ plugin_gen_mem_inline(ptb, begin_op, insn_idx);
+ return;
+ case PLUGIN_GEN_CB_HADDR:
+ plugin_gen_haddr_regular(ptb, begin_op, insn_idx);
+ return;
+ default:
+ g_assert_not_reached();
+ }
+ case PLUGIN_GEN_AFTER_INSN:
+ switch (type) {
+ case PLUGIN_GEN_DISABLE_MEM_HELPER:
+ plugin_gen_disable_mem_helper(ptb, begin_op, insn_idx);
+ return;
+ default:
+ g_assert_not_reached();
+ }
+ default:
+ g_assert_not_reached();
+ }
+}
+
+/* #define DEBUG_PLUGIN_GEN_OPS */
+static void pr_ops(void)
+{
+#ifdef DEBUG_PLUGIN_GEN_OPS
+ TCGOp *op;
+ int i = 0;
+
+ QTAILQ_FOREACH(op, &tcg_ctx->ops, link) {
+ const char *name = "";
+ const char *type = "";
+
+ if (op->opc == INDEX_op_plugin_cb_start) {
+ switch (op->args[0]) {
+ case PLUGIN_GEN_FROM_TB:
+ name = "tb";
+ break;
+ case PLUGIN_GEN_FROM_INSN:
+ name = "insn";
+ break;
+ case PLUGIN_GEN_FROM_MEM:
+ name = "mem";
+ break;
+ case PLUGIN_GEN_AFTER_INSN:
+ name = "after insn";
+ break;
+ default:
+ break;
+ }
+ switch (op->args[1]) {
+ case PLUGIN_GEN_CB_UDATA:
+ type = "udata";
+ break;
+ case PLUGIN_GEN_CB_INLINE:
+ type = "inline";
+ break;
+ case PLUGIN_GEN_CB_MEM:
+ type = "mem";
+ break;
+ case PLUGIN_GEN_CB_HADDR:
+ type = "haddr";
+ break;
+ case PLUGIN_GEN_ENABLE_MEM_HELPER:
+ type = "enable mem helper";
+ break;
+ case PLUGIN_GEN_DISABLE_MEM_HELPER:
+ type = "disable mem helper";
+ break;
+ default:
+ break;
+ }
+ }
+ printf("op[%2i]: %s %s %s\n", i, tcg_op_defs[op->opc].name, name, type);
+ i++;
+ }
+#endif
+}
+
+static void plugin_gen_inject(const struct qemu_plugin_tb *plugin_tb)
+{
+ TCGOp *op;
+ int insn_idx;
+
+ pr_ops();
+ insn_idx = -1;
+ QSIMPLEQ_FOREACH(op, &tcg_ctx->plugin_ops, plugin_link) {
+ enum plugin_gen_from from = op->args[0];
+ enum plugin_gen_cb type = op->args[1];
+
+ tcg_debug_assert(op->opc == INDEX_op_plugin_cb_start);
+ /* ENABLE_MEM_HELPER is the first callback of an instruction */
+ if (from == PLUGIN_GEN_FROM_INSN &&
+ type == PLUGIN_GEN_ENABLE_MEM_HELPER) {
+ insn_idx++;
+ }
+ plugin_inject_cb(plugin_tb, op, insn_idx);
+ }
+ pr_ops();
+}
+
+bool plugin_gen_tb_start(CPUState *cpu, const TranslationBlock *tb)
+{
+ struct qemu_plugin_tb *ptb = tcg_ctx->plugin_tb;
+ bool ret = false;
+
+ if (test_bit(QEMU_PLUGIN_EV_VCPU_TB_TRANS, cpu->plugin_mask)) {
+ ret = true;
+
+ QSIMPLEQ_INIT(&tcg_ctx->plugin_ops);
+ ptb->vaddr = tb->pc;
+ ptb->vaddr2 = -1;
+ get_page_addr_code_hostp(cpu->env_ptr, tb->pc, &ptb->haddr1);
+ ptb->haddr2 = NULL;
+
+ plugin_gen_empty_callback(PLUGIN_GEN_FROM_TB);
+ }
+ return ret;
+}
+
+void plugin_gen_insn_start(CPUState *cpu, const DisasContextBase *db)
+{
+ struct qemu_plugin_tb *ptb = tcg_ctx->plugin_tb;
+ struct qemu_plugin_insn *pinsn;
+
+ pinsn = qemu_plugin_tb_insn_get(ptb);
+ tcg_ctx->plugin_insn = pinsn;
+ pinsn->vaddr = db->pc_next;
+ plugin_gen_empty_callback(PLUGIN_GEN_FROM_INSN);
+
+ /*
+ * Detect page crossing to get the new host address.
+ * Note that we skip this when haddr1 == NULL, e.g. when we're
+ * fetching instructions from a region not backed by RAM.
+ */
+ if (likely(ptb->haddr1 != NULL && ptb->vaddr2 == -1) &&
+ unlikely((db->pc_next & TARGET_PAGE_MASK) !=
+ (db->pc_first & TARGET_PAGE_MASK))) {
+ get_page_addr_code_hostp(cpu->env_ptr, db->pc_next,
+ &ptb->haddr2);
+ ptb->vaddr2 = db->pc_next;
+ }
+ if (likely(ptb->vaddr2 == -1)) {
+ pinsn->haddr = ptb->haddr1 + pinsn->vaddr - ptb->vaddr;
+ } else {
+ pinsn->haddr = ptb->haddr2 + pinsn->vaddr - ptb->vaddr2;
+ }
+}
+
+void plugin_gen_insn_end(void)
+{
+ plugin_gen_empty_callback(PLUGIN_GEN_AFTER_INSN);
+}
+
+void plugin_gen_tb_end(CPUState *cpu)
+{
+ struct qemu_plugin_tb *ptb = tcg_ctx->plugin_tb;
+ int i;
+
+ /* collect instrumentation requests */
+ qemu_plugin_tb_trans_cb(cpu, ptb);
+
+ /* inject the instrumentation at the appropriate places */
+ plugin_gen_inject(ptb);
+
+ /* clean up */
+ for (i = 0; i < PLUGIN_N_CB_SUBTYPES; i++) {
+ if (ptb->cbs[i]) {
+ g_array_set_size(ptb->cbs[i], 0);
+ }
+ }
+ ptb->n = 0;
+ tcg_ctx->plugin_insn = NULL;
+}
new file mode 100644
@@ -0,0 +1,6 @@
+#ifdef CONFIG_PLUGIN
+/* Note: no TCG flags because those are overwritten later */
+DEF_HELPER_2(plugin_vcpu_udata_cb, void, i32, ptr)
+DEF_HELPER_4(plugin_vcpu_mem_cb, void, i32, i32, i64, ptr)
+DEF_HELPER_5(plugin_vcpu_mem_haddr_cb, void, i32, i32, i64, ptr, ptr)
+#endif
@@ -70,6 +70,7 @@ static inline void glue(gen_helper_, name)(dh_retvar_decl(ret) \
#include "trace/generated-helpers.h"
#include "trace/generated-helpers-wrappers.h"
#include "tcg-runtime.h"
+#include "plugin-helpers.h"
#undef DEF_HELPER_FLAGS_0
#undef DEF_HELPER_FLAGS_1
@@ -33,6 +33,7 @@ dh_ctype(ret) HELPER(name) (dh_ctype(t1), dh_ctype(t2), dh_ctype(t3), \
#include "helper.h"
#include "trace/generated-helpers.h"
#include "tcg-runtime.h"
+#include "plugin-helpers.h"
#undef DEF_HELPER_FLAGS_0
#undef DEF_HELPER_FLAGS_1
@@ -55,6 +55,7 @@
#include "helper.h"
#include "trace/generated-helpers.h"
#include "tcg-runtime.h"
+#include "plugin-helpers.h"
#undef str
#undef DEF_HELPER_FLAGS_0
new file mode 100644
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2017, Emilio G. Cota <cota@braap.org>
+ *
+ * License: GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ * plugin-gen.h - TCG-dependent definitions for generating plugin code
+ *
+ * This header should be included only from plugin.c and C files that emit
+ * TCG code.
+ */
+#ifndef QEMU_PLUGIN_GEN_H
+#define QEMU_PLUGIN_GEN_H
+
+#include "qemu/plugin.h"
+#include "tcg/tcg.h"
+
+/* used by plugin_callback_start and plugin_callback_end TCG ops */
+enum plugin_gen_from {
+ PLUGIN_GEN_FROM_TB,
+ PLUGIN_GEN_FROM_INSN,
+ PLUGIN_GEN_FROM_MEM,
+ PLUGIN_GEN_AFTER_INSN,
+ PLUGIN_GEN_N_FROMS,
+};
+
+struct DisasContextBase;
+
+#ifdef CONFIG_PLUGIN
+
+bool plugin_gen_tb_start(CPUState *cpu, const TranslationBlock *tb);
+void plugin_gen_tb_end(CPUState *cpu);
+void plugin_gen_insn_start(CPUState *cpu, const struct DisasContextBase *db);
+void plugin_gen_insn_end(void);
+
+void plugin_gen_disable_mem_helpers(void);
+void plugin_gen_empty_mem_callback(TCGv addr, uint8_t info);
+
+#else /* !CONFIG_PLUGIN */
+
+static inline
+bool plugin_gen_tb_start(CPUState *cpu, const TranslationBlock *tb)
+{
+ return false;
+}
+
+static inline
+void plugin_gen_insn_start(CPUState *cpu, const struct DisasContextBase *db)
+{ }
+
+static inline void plugin_gen_insn_end(void)
+{ }
+
+static inline void plugin_gen_tb_end(CPUState *cpu)
+{ }
+
+static inline void plugin_gen_disable_mem_helpers(void)
+{ }
+
+static inline void plugin_gen_empty_mem_callback(TCGv addr, uint8_t info)
+{ }
+
+#endif /* CONFIG_PLUGIN */
+
+#endif /* QEMU_PLUGIN_GEN_H */
+
@@ -833,6 +833,17 @@ void tcg_gen_goto_tb(unsigned idx);
*/
void tcg_gen_lookup_and_goto_ptr(void);
+static inline void tcg_gen_plugin_cb_start(unsigned from, unsigned type,
+ unsigned wr)
+{
+ tcg_gen_op3(INDEX_op_plugin_cb_start, from, type, wr);
+}
+
+static inline void tcg_gen_plugin_cb_end(void)
+{
+ tcg_emit_op(INDEX_op_plugin_cb_end);
+}
+
#if TARGET_LONG_BITS == 32
#define tcg_temp_new() tcg_temp_new_i32()
#define tcg_global_reg_new tcg_global_reg_new_i32
@@ -198,6 +198,9 @@ DEF(goto_tb, 0, 0, 1, TCG_OPF_BB_EXIT | TCG_OPF_BB_END)
DEF(goto_ptr, 0, 1, 0,
TCG_OPF_BB_EXIT | TCG_OPF_BB_END | IMPL(TCG_TARGET_HAS_goto_ptr))
+DEF(plugin_cb_start, 0, 0, 3, TCG_OPF_NOT_PRESENT)
+DEF(plugin_cb_end, 0, 0, 0, TCG_OPF_NOT_PRESENT)
+
DEF(qemu_ld_i32, 1, TLADDR_ARGS, 1,
TCG_OPF_CALL_CLOBBER | TCG_OPF_SIDE_EFFECTS)
DEF(qemu_st_i32, 0, TLADDR_ARGS + 1, 1,
@@ -729,6 +729,15 @@ void tcg_region_init(void)
#endif
}
+static void alloc_tcg_plugin_context(TCGContext *s)
+{
+#ifdef CONFIG_PLUGIN
+ s->plugin_tb = g_new0(struct qemu_plugin_tb, 1);
+ s->plugin_tb->insns =
+ g_ptr_array_new_with_free_func(qemu_plugin_insn_cleanup_fn);
+#endif
+}
+
/*
* All TCG threads except the parent (i.e. the one that called tcg_context_init
* and registered the target's TCG globals) must register with this function
@@ -772,6 +781,10 @@ void tcg_register_thread(void)
g_assert(n < max_cpus);
atomic_set(&tcg_ctxs[n], s);
+ if (n > 0) {
+ alloc_tcg_plugin_context(s);
+ }
+
tcg_ctx = s;
qemu_mutex_lock(®ion.lock);
err = tcg_region_initial_alloc__locked(tcg_ctx);
@@ -968,6 +981,8 @@ void tcg_context_init(TCGContext *s)
indirect_reg_alloc_order[i] = tcg_target_reg_alloc_order[i];
}
+ alloc_tcg_plugin_context(s);
+
tcg_ctx = s;
/*
* In user-mode we simply share the init context among threads, since we
@@ -1671,6 +1686,13 @@ void tcg_gen_callN(void *func, TCGTemp *ret, int nargs, TCGTemp **args)
flags = info->flags;
sizemask = info->sizemask;
+#ifdef CONFIG_PLUGIN
+ /* detect non-plugin helpers */
+ if (tcg_ctx->plugin_insn && unlikely(strncmp(info->name, "plugin_", 7))) {
+ tcg_ctx->plugin_insn->calls_helpers = true;
+ }
+#endif
+
#if defined(__sparc__) && !defined(__arch64__) \
&& !defined(CONFIG_TCG_INTERPRETER)
/* We have 64-bit values in one register, but need to pass as two
@@ -625,6 +625,9 @@ typedef struct TCGOp {
/* Next and previous opcodes. */
QTAILQ_ENTRY(TCGOp) link;
+#ifdef CONFIG_PLUGIN
+ QSIMPLEQ_ENTRY(TCGOp) plugin_link;
+#endif
/* Arguments for the opcode. */
TCGArg args[MAX_OPC_PARAM];
@@ -726,6 +729,23 @@ struct TCGContext {
TCGLabel *exitreq_label;
+#ifdef CONFIG_PLUGIN
+ /*
+ * We keep one plugin_tb struct per TCGContext. Note that on every TB
+ * translation we clear but do not free its contents; this way we
+ * avoid a lot of malloc/free churn, since after a few TB's it's
+ * unlikely that we'll need to allocate either more instructions or more
+ * space for instructions (for variable-instruction-length ISAs).
+ */
+ struct qemu_plugin_tb *plugin_tb;
+
+ /* descriptor of the instruction being translated */
+ struct qemu_plugin_insn *plugin_insn;
+
+ /* list to quickly access the injected ops */
+ QSIMPLEQ_HEAD(, TCGOp) plugin_ops;
+#endif
+
TCGTempSet free_temps[TCG_TYPE_COUNT * 2];
TCGTemp temps[TCG_MAX_TEMPS]; /* globals first, temps after */