diff options
Diffstat (limited to 'contrib/plugins/uftrace.c')
| -rw-r--r-- | contrib/plugins/uftrace.c | 878 |
1 files changed, 878 insertions, 0 deletions
diff --git a/contrib/plugins/uftrace.c b/contrib/plugins/uftrace.c new file mode 100644 index 0000000..b7d6124 --- /dev/null +++ b/contrib/plugins/uftrace.c @@ -0,0 +1,878 @@ +/* + * Copyright (C) 2025, Pierrick Bouvier <pierrick.bouvier@linaro.org> + * + * Generates a trace compatible with uftrace (similar to uftrace record). + * https://github.com/namhyung/uftrace + * + * See docs/about/emulation.rst|Uftrace for details and examples. + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include <qemu-plugin.h> +#include <glib.h> +#include <stdio.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <time.h> +#include <unistd.h> + +#define MiB (INT64_C(1) << 20) +#define NANOSECONDS_PER_SECOND 1000000000LL +#define TRACE_FLUSH_SIZE (32 * MiB) +#define TRACE_ID_SCALE 100 + +QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION; + +typedef struct { + GArray *s; +} Callstack; + +typedef struct { + uint64_t pc; + uint64_t frame_pointer; +} CallstackEntry; + +typedef struct { + GArray *t; + GString *path; + GString *name; + uint32_t id; +} Trace; + +typedef struct Cpu Cpu; + +typedef struct { + void (*init)(Cpu *cpu); + void (*end)(Cpu *cpu); + uint64_t (*get_frame_pointer)(Cpu *cpu); + uint8_t (*get_privilege_level)(Cpu *cpu); + uint8_t (*num_privilege_levels)(void); + const char *(*get_privilege_level_name)(uint8_t pl); + bool (*does_insn_modify_frame_pointer)(const char *disas); +} CpuOps; + +typedef struct Cpu { + Trace *trace; + Callstack *cs; + uint8_t privilege_level; + GArray *traces; /* Trace *traces [] */ + GByteArray *buf; + CpuOps ops; + void *arch; +} Cpu; + +typedef enum { + AARCH64_EL0_SECURE, + AARCH64_EL0_NONSECURE, + AARCH64_EL0_REALM, + AARCH64_EL1_SECURE, + AARCH64_EL1_NONSECURE, + AARCH64_EL1_REALM, + AARCH64_EL2_SECURE, + AARCH64_EL2_NONSECURE, + AARCH64_EL2_REALM, + AARCH64_EL3, + AARCH64_PRIVILEGE_LEVEL_MAX, +} Aarch64PrivilegeLevel; + +typedef struct { + struct qemu_plugin_register *reg_fp; + struct qemu_plugin_register *reg_cpsr; + struct qemu_plugin_register *reg_scr_el3; +} Aarch64Cpu; + +typedef enum { + X64_RING0, + X64_RING1, + X64_RING2, + X64_RING3, + X64_REAL_MODE, + X64_PRIVILEGE_LEVEL_MAX, +} X64PrivilegeLevel; + +typedef struct { + struct qemu_plugin_register *reg_rbp; + struct qemu_plugin_register *reg_cs; + struct qemu_plugin_register *reg_cr0; +} X64Cpu; + +typedef struct { + uint64_t timestamp; + uint64_t data; +} UftraceEntry; + +typedef enum { + UFTRACE_ENTRY, + UFTRACE_EXIT, + UFTRACE_LOST, + UFTRACE_EVENT, +} UftraceRecordType; + +static struct qemu_plugin_scoreboard *score; +static bool trace_privilege_level; +static CpuOps arch_ops; + +static uint64_t gettime_ns(void) +{ +#ifdef _WIN32 + /* + * On Windows, timespec_get is available only with UCRT, but not with + * MinGW64 environment. Simplify by using only gettimeofday on this + * platform. This may result in a precision loss. + */ + struct timeval tv; + gettimeofday(&tv, NULL); + uint64_t now_ns = tv.tv_sec * NANOSECONDS_PER_SECOND + tv.tv_usec * 1000; +#else + /* We need nanosecond precision for short lived functions. */ + struct timespec ts; + timespec_get(&ts, TIME_UTC); + uint64_t now_ns = ts.tv_sec * NANOSECONDS_PER_SECOND + ts.tv_nsec; +#endif + return now_ns; +} + +static void uftrace_write_map(bool system_emulation) +{ + const char *path = "./uftrace.data/sid-0.map"; + + if (system_emulation && access(path, F_OK) == 0) { + /* do not erase existing map in system emulation, as a custom one might + * already have been generated by uftrace_symbols.py */ + return; + } + + FILE *sid_map = fopen(path, "w"); + g_assert(sid_map); + + if (system_emulation) { + fprintf(sid_map, + "# map stack on highest address possible, to prevent uftrace\n" + "# from considering any kernel address\n"); + fprintf(sid_map, + "ffffffffffff-ffffffffffff rw-p 00000000 00:00 0 [stack]\n"); + } else { + /* in user mode, copy /proc/self/maps instead */ + FILE *self_map = fopen("/proc/self/maps", "r"); + g_assert(self_map); + for (;;) { + int c = fgetc(self_map); + if (c == EOF) { + break; + } + fputc(c, sid_map); + } + fclose(self_map); + } + fclose(sid_map); +} + +static void uftrace_write_task(const GArray *traces) +{ + FILE *task = fopen("./uftrace.data/task.txt", "w"); + g_assert(task); + for (int i = 0; i < traces->len; ++i) { + Trace *t = g_array_index(traces, Trace*, i); + fprintf(task, "SESS timestamp=0.0 pid=%"PRIu32" sid=0 exename=\"%s\"\n", + t->id, t->name->str); + fprintf(task, "TASK timestamp=0.0 tid=%"PRIu32" pid=%"PRIu32"\n", + t->id, t->id); + } + fclose(task); +} + +static void uftrace_write_info(const GArray *traces) +{ + g_autoptr(GString) taskinfo_tids = g_string_new("taskinfo:tids="); + for (int i = 0; i < traces->len; ++i) { + Trace *t = g_array_index(traces, Trace*, i); + const char *delim = i > 0 ? "," : ""; + g_string_append_printf(taskinfo_tids, "%s%"PRIu32, delim, t->id); + } + + g_autoptr(GString) taskinfo_nr_tid = g_string_new("taskinfo:nr_tid="); + g_string_append_printf(taskinfo_nr_tid, "%d", traces->len); + + FILE *info = fopen("./uftrace.data/info", "w"); + g_assert(info); + /* + * $ uftrace dump --debug + * uftrace file header: magic = 4674726163652100 + * uftrace file header: version = 4 + * uftrace file header: header size = 40 + * uftrace file header: endian = 1 (little) + * uftrace file header: class = 2 (64 bit) + * uftrace file header: features = 0x1263 (PLTHOOK | ... + * uftrace file header: info = 0x7bff (EXE_NAME | ... + * <0000000000000000>: 46 74 72 61 63 65 21 00 04 00 00 00 28 00 01 02 + * <0000000000000010>: 63 12 00 00 00 00 00 00 ff 7b 00 00 00 00 00 00 + * <0000000000000020>: 00 04 00 00 00 00 00 00 + */ + const uint8_t header[] = {0x46, 0x74, 0x72, 0x61, 0x63, 0x65, 0x21, 0x00, + 0x04, 0x00, 0x00, 0x00, 0x28, 0x00, 0x01, 0x02, + 0x63, 0x12, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0xff, 0x7b, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; + size_t wrote = fwrite(header, sizeof(header), 1, info); + g_assert(wrote == 1); + const char *info_data[] = { + "exename:", + "build_id:0000000000000000000000000000000000000000", + "exit_status:", + "cmdline:", + "cpuinfo:lines=2", + "cpuinfo:nr_cpus=", + "cpuinfo:desc=", + "meminfo:", + "osinfo:lines=3", + "osinfo:kernel=", + "osinfo:hostname=", + "osinfo:distro=", + "taskinfo:lines=2", + taskinfo_nr_tid->str, + taskinfo_tids->str, + "usageinfo:lines=6", + "usageinfo:systime=", + "usageinfo:usrtime=", + "usageinfo:ctxsw=", + "usageinfo:maxrss=", + "usageinfo:pagefault=", + "usageinfo:iops=", + "loadinfo:", + "record_date:", + "elapsed_time:", + "pattern_type:regex", + "uftrace_version:", + "utc_offset:", + 0}; + const char **info_data_it = info_data; + while (*(info_data_it)) { + fprintf(info, "%s\n", *info_data_it); + ++info_data_it; + } + fclose(info); +} + +static Callstack *callstack_new(void) +{ + Callstack *cs = g_new0(Callstack, 1); + cs->s = g_array_new(false, false, sizeof(CallstackEntry)); + return cs; +} + +static void callstack_free(Callstack *cs) +{ + g_array_free(cs->s, true); + cs->s = NULL; + g_free(cs); +} + +static size_t callstack_depth(const Callstack *cs) +{ + return cs->s->len; +} + +static size_t callstack_empty(const Callstack *cs) +{ + return callstack_depth(cs) == 0; +} + +static void callstack_clear(Callstack *cs) +{ + g_array_set_size(cs->s, 0); +} + +static const CallstackEntry *callstack_at(const Callstack *cs, size_t depth) +{ + g_assert(depth > 0); + g_assert(depth <= callstack_depth(cs)); + return &g_array_index(cs->s, CallstackEntry, depth - 1); +} + +static CallstackEntry callstack_top(const Callstack *cs) +{ + if (callstack_depth(cs) >= 1) { + return *callstack_at(cs, callstack_depth(cs)); + } + return (CallstackEntry){}; +} + +static CallstackEntry callstack_caller(const Callstack *cs) +{ + if (callstack_depth(cs) >= 2) { + return *callstack_at(cs, callstack_depth(cs) - 1); + } + return (CallstackEntry){}; +} + +static void callstack_push(Callstack *cs, CallstackEntry e) +{ + g_array_append_val(cs->s, e); +} + +static CallstackEntry callstack_pop(Callstack *cs) +{ + g_assert(!callstack_empty(cs)); + CallstackEntry e = callstack_top(cs); + g_array_set_size(cs->s, callstack_depth(cs) - 1); + return e; +} + +static Trace *trace_new(uint32_t id, GString *name) +{ + Trace *t = g_new0(Trace, 1); + t->t = g_array_new(false, false, sizeof(UftraceEntry)); + t->path = g_string_new(NULL); + g_string_append_printf(t->path, "./uftrace.data/%"PRIu32".dat", id); + t->name = g_string_new(name->str); + t->id = id; + return t; +} + +static void trace_free(Trace *t) +{ + g_assert(t->t->len == 0); + g_array_free(t->t, true); + t->t = NULL; + g_string_free(t->path, true); + t->path = NULL; + g_string_free(t->name, true); + t->name = NULL; + g_free(t); +} + +static void trace_flush(Trace *t, bool append) +{ + int create_dir = g_mkdir_with_parents("./uftrace.data", + S_IRWXU | S_IRWXG | S_IRWXO); + g_assert(create_dir == 0); + FILE *dat = fopen(t->path->str, append ? "a" : "w"); + g_assert(dat); + GArray *data = t->t; + if (data->len) { + size_t wrote = fwrite(data->data, sizeof(UftraceEntry), data->len, dat); + g_assert(wrote == data->len); + } + fclose(dat); + g_array_set_size(data, 0); +} + +static void trace_add_entry(Trace *t, uint64_t timestamp, uint64_t pc, + size_t depth, UftraceRecordType type) +{ + /* https://github.com/namhyung/uftrace/blob/v0.18/libmcount/record.c#L909 */ + const uint64_t record_magic = 0x5; + uint64_t data = type | (record_magic << 3); + data += depth << 6; + data += pc << 16; + UftraceEntry e = {.timestamp = timestamp, .data = data}; + g_array_append_val(t->t, e); + if (t->t->len * sizeof(UftraceEntry) > TRACE_FLUSH_SIZE) { + trace_flush(t, true); + } +} + +static void trace_enter_function(Trace *t, uint64_t timestamp, + uint64_t pc, size_t depth) +{ + trace_add_entry(t, timestamp, pc, depth, UFTRACE_ENTRY); +} + +static void trace_exit_function(Trace *t, uint64_t timestamp, + uint64_t pc, size_t depth) +{ + trace_add_entry(t, timestamp, pc, depth, UFTRACE_EXIT); +} + +static void trace_enter_stack(Trace *t, Callstack *cs, uint64_t timestamp) +{ + for (size_t depth = 1; depth <= callstack_depth(cs); ++depth) { + trace_enter_function(t, timestamp, callstack_at(cs, depth)->pc, depth); + } +} + +static void trace_exit_stack(Trace *t, Callstack *cs, uint64_t timestamp) +{ + for (size_t depth = callstack_depth(cs); depth > 0; --depth) { + trace_exit_function(t, timestamp, callstack_at(cs, depth)->pc, depth); + } +} + +static uint64_t cpu_read_register64(Cpu *cpu, struct qemu_plugin_register *reg) +{ + GByteArray *buf = cpu->buf; + g_byte_array_set_size(buf, 0); + size_t sz = qemu_plugin_read_register(reg, buf); + g_assert(sz == 8); + g_assert(buf->len == 8); + return *((uint64_t *) buf->data); +} + +static uint32_t cpu_read_register32(Cpu *cpu, struct qemu_plugin_register *reg) +{ + GByteArray *buf = cpu->buf; + g_byte_array_set_size(buf, 0); + size_t sz = qemu_plugin_read_register(reg, buf); + g_assert(sz == 4); + g_assert(buf->len == 4); + return *((uint32_t *) buf->data); +} + +static uint64_t cpu_read_memory64(Cpu *cpu, uint64_t addr) +{ + g_assert(addr); + GByteArray *buf = cpu->buf; + g_byte_array_set_size(buf, 0); + bool read = qemu_plugin_read_memory_vaddr(addr, buf, 8); + if (!read) { + return 0; + } + g_assert(buf->len == 8); + return *((uint64_t *) buf->data); +} + +static void cpu_unwind_stack(Cpu *cpu, uint64_t frame_pointer, uint64_t pc) +{ + g_assert(callstack_empty(cpu->cs)); + + #define UNWIND_STACK_MAX_DEPTH 1024 + CallstackEntry unwind[UNWIND_STACK_MAX_DEPTH]; + size_t depth = 0; + do { + /* check we don't have an infinite stack */ + for (size_t i = 0; i < depth; ++i) { + if (frame_pointer == unwind[i].frame_pointer) { + break; + } + } + CallstackEntry e = {.frame_pointer = frame_pointer, .pc = pc}; + unwind[depth] = e; + depth++; + if (frame_pointer) { + frame_pointer = cpu_read_memory64(cpu, frame_pointer); + } + pc = cpu_read_memory64(cpu, frame_pointer + 8); /* read previous lr */ + } while (frame_pointer && pc && depth < UNWIND_STACK_MAX_DEPTH); + #undef UNWIND_STACK_MAX_DEPTH + + /* push it from bottom to top */ + while (depth) { + callstack_push(cpu->cs, unwind[depth - 1]); + --depth; + } +} + +static struct qemu_plugin_register *plugin_find_register(const char *name) +{ + g_autoptr(GArray) regs = qemu_plugin_get_registers(); + for (int i = 0; i < regs->len; ++i) { + qemu_plugin_reg_descriptor *reg; + reg = &g_array_index(regs, qemu_plugin_reg_descriptor, i); + if (!strcmp(reg->name, name)) { + return reg->handle; + } + } + return NULL; +} + +static uint8_t aarch64_num_privilege_levels(void) +{ + return AARCH64_PRIVILEGE_LEVEL_MAX; +} + +static const char *aarch64_get_privilege_level_name(uint8_t pl) +{ + switch (pl) { + case AARCH64_EL0_SECURE: return "S-EL0"; + case AARCH64_EL0_NONSECURE: return "NS-EL0"; + case AARCH64_EL0_REALM: return "R-EL0"; + case AARCH64_EL1_SECURE: return "S-EL1"; + case AARCH64_EL1_NONSECURE: return "NS-EL1"; + case AARCH64_EL1_REALM: return "R-EL1"; + case AARCH64_EL2_SECURE: return "S-EL2"; + case AARCH64_EL2_NONSECURE: return "NS-EL2"; + case AARCH64_EL2_REALM: return "R-EL2"; + case AARCH64_EL3: return "EL3"; + default: + g_assert_not_reached(); + } +} + +static uint8_t aarch64_get_privilege_level(Cpu *cpu_) +{ + Aarch64Cpu *cpu = cpu_->arch; + /* + * QEMU gdbstub does not provide access to CurrentEL, + * so we use CPSR instead. + */ + uint8_t el = cpu_read_register32(cpu_, cpu->reg_cpsr) >> 2 & 0b11; + + if (el == 3) { + return AARCH64_EL3; + } + + uint8_t ss = AARCH64_EL0_SECURE; + if (!cpu->reg_scr_el3) { + ss = AARCH64_EL0_NONSECURE; + } + uint64_t scr_el3 = cpu_read_register64(cpu_, cpu->reg_scr_el3); + uint64_t ns = (scr_el3 >> 0) & 0b1; + uint64_t nse = (scr_el3 >> 62) & 0b1; + switch (nse << 1 | ns) { + case 0b00: + ss = AARCH64_EL0_SECURE; + break; + case 0b01: + ss = AARCH64_EL0_NONSECURE; + break; + case 0b11: + ss = AARCH64_EL0_REALM; + break; + default: + g_assert_not_reached(); + } + + const uint8_t num_ss = 3; + Aarch64PrivilegeLevel pl = el * num_ss + ss; + return pl; +} + +static uint64_t aarch64_get_frame_pointer(Cpu *cpu_) +{ + Aarch64Cpu *cpu = cpu_->arch; + return cpu_read_register64(cpu_, cpu->reg_fp); +} + +static void aarch64_init(Cpu *cpu_) +{ + Aarch64Cpu *cpu = g_new0(Aarch64Cpu, 1); + cpu_->arch = cpu; + cpu->reg_fp = plugin_find_register("x29"); + if (!cpu->reg_fp) { + fprintf(stderr, "uftrace plugin: frame pointer register (x29) is not " + "available. Please use an AArch64 cpu (or -cpu max).\n"); + g_abort(); + } + cpu->reg_cpsr = plugin_find_register("cpsr"); + g_assert(cpu->reg_cpsr); + cpu->reg_scr_el3 = plugin_find_register("SCR_EL3"); + /* scr_el3 is optional */ +} + +static void aarch64_end(Cpu *cpu) +{ + g_free(cpu->arch); +} + +static bool aarch64_does_insn_modify_frame_pointer(const char *disas) +{ + /* + * Check if current instruction concerns fp register "x29". + * We add a prefix space to make sure we don't match addresses dump + * in disassembly. + */ + return strstr(disas, " x29"); +} + +static CpuOps aarch64_ops = { + .init = aarch64_init, + .end = aarch64_end, + .get_frame_pointer = aarch64_get_frame_pointer, + .get_privilege_level = aarch64_get_privilege_level, + .num_privilege_levels = aarch64_num_privilege_levels, + .get_privilege_level_name = aarch64_get_privilege_level_name, + .does_insn_modify_frame_pointer = aarch64_does_insn_modify_frame_pointer, +}; + +static uint8_t x64_num_privilege_levels(void) +{ + return X64_PRIVILEGE_LEVEL_MAX; +} + +static const char *x64_get_privilege_level_name(uint8_t pl) +{ + switch (pl) { + case X64_RING0: return "Ring0"; + case X64_RING1: return "Ring1"; + case X64_RING2: return "Ring2"; + case X64_RING3: return "Ring3"; + case X64_REAL_MODE: return "RealMode"; + default: + g_assert_not_reached(); + } +} + +static uint8_t x64_get_privilege_level(Cpu *cpu_) +{ + X64Cpu *cpu = cpu_->arch; + uint64_t cr0 = cpu_read_register64(cpu_, cpu->reg_cr0); + uint64_t protected_mode = (cr0 >> 0) & 0b1; + if (!protected_mode) { + return X64_REAL_MODE; + } + uint32_t cs = cpu_read_register32(cpu_, cpu->reg_cs); + uint32_t ring_level = (cs >> 0) & 0b11; + return ring_level; +} + +static uint64_t x64_get_frame_pointer(Cpu *cpu_) +{ + X64Cpu *cpu = cpu_->arch; + return cpu_read_register64(cpu_, cpu->reg_rbp); +} + +static void x64_init(Cpu *cpu_) +{ + X64Cpu *cpu = g_new0(X64Cpu, 1); + cpu_->arch = cpu; + cpu->reg_rbp = plugin_find_register("rbp"); + g_assert(cpu->reg_rbp); + cpu->reg_cs = plugin_find_register("cs"); + g_assert(cpu->reg_cs); + cpu->reg_cr0 = plugin_find_register("cr0"); + g_assert(cpu->reg_cr0); +} + +static void x64_end(Cpu *cpu) +{ + g_free(cpu->arch); +} + +static bool x64_does_insn_modify_frame_pointer(const char *disas) +{ + return strstr(disas, "rbp"); +} + +static CpuOps x64_ops = { + .init = x64_init, + .end = x64_end, + .get_frame_pointer = x64_get_frame_pointer, + .get_privilege_level = x64_get_privilege_level, + .num_privilege_levels = x64_num_privilege_levels, + .get_privilege_level_name = x64_get_privilege_level_name, + .does_insn_modify_frame_pointer = x64_does_insn_modify_frame_pointer, +}; + +static void track_privilege_change(unsigned int cpu_index, void *udata) +{ + Cpu *cpu = qemu_plugin_scoreboard_find(score, cpu_index); + uint8_t new_pl = cpu->ops.get_privilege_level(cpu); + + if (new_pl == cpu->privilege_level) { + return; + } + + uint64_t pc = (uintptr_t) udata; + uint64_t timestamp = gettime_ns(); + + trace_exit_stack(cpu->trace, cpu->cs, timestamp); + callstack_clear(cpu->cs); + + cpu->privilege_level = new_pl; + cpu->trace = g_array_index(cpu->traces, Trace*, new_pl); + + cpu_unwind_stack(cpu, cpu->ops.get_frame_pointer(cpu), pc); + trace_enter_stack(cpu->trace, cpu->cs, timestamp); +} + +static void track_callstack(unsigned int cpu_index, void *udata) +{ + uint64_t pc = (uintptr_t) udata; + Cpu *cpu = qemu_plugin_scoreboard_find(score, cpu_index); + uint64_t timestamp = gettime_ns(); + Callstack *cs = cpu->cs; + Trace *t = cpu->trace; + + uint64_t fp = cpu->ops.get_frame_pointer(cpu); + if (!fp && callstack_empty(cs)) { + /* + * We simply push current pc. Note that we won't detect symbol change as + * long as a proper call does not happen. + */ + callstack_push(cs, (CallstackEntry){.frame_pointer = fp, .pc = pc}); + trace_enter_function(t, timestamp, pc, callstack_depth(cs)); + return; + } + + CallstackEntry top = callstack_top(cs); + if (fp == top.frame_pointer) { + /* same function */ + return; + } + + CallstackEntry caller = callstack_caller(cs); + if (fp == caller.frame_pointer) { + /* return */ + CallstackEntry e = callstack_pop(cs); + trace_exit_function(t, timestamp, e.pc, callstack_depth(cs)); + return; + } + + uint64_t caller_fp = fp ? cpu_read_memory64(cpu, fp) : 0; + if (caller_fp == top.frame_pointer) { + /* call */ + callstack_push(cs, (CallstackEntry){.frame_pointer = fp, .pc = pc}); + trace_enter_function(t, timestamp, pc, callstack_depth(cs)); + return; + } + + /* discontinuity, exit current stack and unwind new one */ + trace_exit_stack(t, cs, timestamp); + callstack_clear(cs); + + cpu_unwind_stack(cpu, fp, pc); + trace_enter_stack(t, cs, timestamp); +} + +static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb) +{ + size_t n_insns = qemu_plugin_tb_n_insns(tb); + uintptr_t tb_pc = qemu_plugin_tb_vaddr(tb); + + if (trace_privilege_level) { + qemu_plugin_register_vcpu_tb_exec_cb(tb, track_privilege_change, + QEMU_PLUGIN_CB_R_REGS, + (void *) tb_pc); + } + + /* + * Callbacks and inline instrumentation are inserted before an instruction. + * Thus, to see instruction effect, we need to wait for next one. + * Potentially, the last instruction of a block could modify the frame + * pointer. Thus, we need to always instrument first instruction in a tb. + */ + bool instrument_insn = true; + for (size_t i = 0; i < n_insns; i++) { + struct qemu_plugin_insn *insn = qemu_plugin_tb_get_insn(tb, i); + + if (instrument_insn) { + uintptr_t pc = qemu_plugin_insn_vaddr(insn); + qemu_plugin_register_vcpu_insn_exec_cb(insn, track_callstack, + QEMU_PLUGIN_CB_R_REGS, + (void *) pc); + instrument_insn = false; + } + + char *disas = qemu_plugin_insn_disas(insn); + if (arch_ops.does_insn_modify_frame_pointer(disas)) { + instrument_insn = true; + } + } +} + +static void vcpu_init(qemu_plugin_id_t id, unsigned int vcpu_index) +{ + Cpu *cpu = qemu_plugin_scoreboard_find(score, vcpu_index); + cpu->ops = arch_ops; + + cpu->ops.init(cpu); + cpu->buf = g_byte_array_new(); + cpu->traces = g_array_new(0, 0, sizeof(Trace *)); + + g_assert(vcpu_index < UINT32_MAX / TRACE_ID_SCALE); + g_assert(cpu->ops.num_privilege_levels() < TRACE_ID_SCALE); + /* trace_id is: cpu_number * TRACE_ID_SCALE + privilege_level */ + uint32_t trace_id = (vcpu_index + 1) * TRACE_ID_SCALE; + + if (trace_privilege_level) { + for (uint8_t pl = 0; pl < cpu->ops.num_privilege_levels(); ++pl) { + g_autoptr(GString) trace_name = g_string_new(NULL); + g_string_append_printf(trace_name, "cpu%u %s", vcpu_index, + cpu->ops.get_privilege_level_name(pl)); + Trace *t = trace_new(trace_id + pl, trace_name); + g_array_append_val(cpu->traces, t); + } + } else { + g_autoptr(GString) trace_name = g_string_new(NULL); + g_string_append_printf(trace_name, "cpu%u", vcpu_index); + Trace *t = trace_new(trace_id, trace_name); + g_array_append_val(cpu->traces, t); + } + + for (size_t i = 0; i < cpu->traces->len; ++i) { + /* create/truncate trace files */ + Trace *t = g_array_index(cpu->traces, Trace*, i); + trace_flush(t, false); + } + + cpu->cs = callstack_new(); + cpu->trace = g_array_index(cpu->traces, Trace*, cpu->privilege_level); +} + +static void vcpu_end(unsigned int vcpu_index) +{ + Cpu *cpu = qemu_plugin_scoreboard_find(score, vcpu_index); + g_byte_array_free(cpu->buf, true); + + for (size_t i = 0; i < cpu->traces->len; ++i) { + Trace *t = g_array_index(cpu->traces, Trace*, i); + trace_free(t); + } + + g_array_free(cpu->traces, true); + callstack_free(cpu->cs); + memset(cpu, 0, sizeof(Cpu)); +} + +static void at_exit(qemu_plugin_id_t id, void *data) +{ + bool system_emulation = (bool) data; + g_autoptr(GArray) traces = g_array_new(0, 0, sizeof(Trace *)); + + for (size_t i = 0; i < qemu_plugin_num_vcpus(); ++i) { + Cpu *cpu = qemu_plugin_scoreboard_find(score, i); + for (size_t j = 0; j < cpu->traces->len; ++j) { + Trace *t = g_array_index(cpu->traces, Trace*, j); + trace_flush(t, true); + g_array_append_val(traces, t); + } + } + + uftrace_write_map(system_emulation); + uftrace_write_info(traces); + uftrace_write_task(traces); + + for (size_t i = 0; i < qemu_plugin_num_vcpus(); ++i) { + vcpu_end(i); + } + + qemu_plugin_scoreboard_free(score); +} + +QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id, + const qemu_info_t *info, + int argc, char **argv) +{ + for (int i = 0; i < argc; i++) { + char *opt = argv[i]; + g_auto(GStrv) tokens = g_strsplit(opt, "=", 2); + if (g_strcmp0(tokens[0], "trace-privilege-level") == 0) { + if (!qemu_plugin_bool_parse(tokens[0], tokens[1], + &trace_privilege_level)) { + fprintf(stderr, "boolean argument parsing failed: %s\n", opt); + return -1; + } + } else { + fprintf(stderr, "option parsing failed: %s\n", opt); + return -1; + } + } + + if (!strcmp(info->target_name, "aarch64")) { + arch_ops = aarch64_ops; + } else if (!strcmp(info->target_name, "x86_64")) { + arch_ops = x64_ops; + } else { + fprintf(stderr, "plugin uftrace: %s target is not supported\n", + info->target_name); + return 1; + } + + score = qemu_plugin_scoreboard_new(sizeof(Cpu)); + qemu_plugin_register_vcpu_init_cb(id, vcpu_init); + qemu_plugin_register_atexit_cb(id, at_exit, (void *) info->system_emulation); + qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans); + + return 0; +} |