diff options
Diffstat (limited to 'disas/disas.c')
| -rw-r--r-- | disas/disas.c | 399 |
1 files changed, 399 insertions, 0 deletions
diff --git a/disas/disas.c b/disas/disas.c new file mode 100644 index 0000000000..d46f638a72 --- /dev/null +++ b/disas/disas.c @@ -0,0 +1,399 @@ +/* General "disassemble this chunk" code. Used for debugging. */ +#include "qemu/osdep.h" +#include "disas/dis-asm.h" +#include "elf.h" +#include "qemu/qemu-print.h" + +#include "disas/disas.h" +#include "disas/capstone.h" + +typedef struct CPUDebug { + struct disassemble_info info; + CPUState *cpu; +} CPUDebug; + +/* Filled in by elfload.c. Simplistic, but will do for now. */ +struct syminfo *syminfos = NULL; + +/* + * Get LENGTH bytes from info's buffer, at host address memaddr. + * Transfer them to myaddr. + */ +static int host_read_memory(bfd_vma memaddr, bfd_byte *myaddr, int length, + struct disassemble_info *info) +{ + if (memaddr < info->buffer_vma + || memaddr + length > info->buffer_vma + info->buffer_length) { + /* Out of bounds. Use EIO because GDB uses it. */ + return EIO; + } + memcpy (myaddr, info->buffer + (memaddr - info->buffer_vma), length); + return 0; +} + +/* + * Get LENGTH bytes from info's buffer, at target address memaddr. + * Transfer them to myaddr. + */ +static int target_read_memory(bfd_vma memaddr, bfd_byte *myaddr, int length, + struct disassemble_info *info) +{ + CPUDebug *s = container_of(info, CPUDebug, info); + int r = cpu_memory_rw_debug(s->cpu, memaddr, myaddr, length, 0); + return r ? EIO : 0; +} + +/* + * Print an error message. We can assume that this is in response to + * an error return from {host,target}_read_memory. + */ +static void perror_memory(int status, bfd_vma memaddr, + struct disassemble_info *info) +{ + if (status != EIO) { + /* Can't happen. */ + info->fprintf_func(info->stream, "Unknown error %d\n", status); + } else { + /* Address between memaddr and memaddr + len was out of bounds. */ + info->fprintf_func(info->stream, + "Address 0x%" PRIx64 " is out of bounds.\n", + memaddr); + } +} + +/* Print address in hex. */ +static void print_address(bfd_vma addr, struct disassemble_info *info) +{ + info->fprintf_func(info->stream, "0x%" PRIx64, addr); +} + +/* Print address in hex, truncated to the width of a host virtual address. */ +static void host_print_address(bfd_vma addr, struct disassemble_info *info) +{ + print_address((uintptr_t)addr, info); +} + +/* Stub prevents some fruitless earching in optabs disassemblers. */ +static int symbol_at_address(bfd_vma addr, struct disassemble_info *info) +{ + return 1; +} + +static int print_insn_objdump(bfd_vma pc, disassemble_info *info, + const char *prefix) +{ + int i, n = info->buffer_length; + g_autofree uint8_t *buf = g_malloc(n); + + if (info->read_memory_func(pc, buf, n, info) == 0) { + for (i = 0; i < n; ++i) { + if (i % 32 == 0) { + info->fprintf_func(info->stream, "\n%s: ", prefix); + } + info->fprintf_func(info->stream, "%02x", buf[i]); + } + } else { + info->fprintf_func(info->stream, "unable to read memory"); + } + return n; +} + +static int print_insn_od_host(bfd_vma pc, disassemble_info *info) +{ + return print_insn_objdump(pc, info, "OBJD-H"); +} + +static int print_insn_od_target(bfd_vma pc, disassemble_info *info) +{ + return print_insn_objdump(pc, info, "OBJD-T"); +} + +static void initialize_debug(CPUDebug *s) +{ + memset(s, 0, sizeof(*s)); + s->info.arch = bfd_arch_unknown; + s->info.cap_arch = -1; + s->info.cap_insn_unit = 4; + s->info.cap_insn_split = 4; + s->info.memory_error_func = perror_memory; + s->info.symbol_at_address_func = symbol_at_address; +} + +static void initialize_debug_target(CPUDebug *s, CPUState *cpu) +{ + initialize_debug(s); + + s->cpu = cpu; + s->info.read_memory_func = target_read_memory; + s->info.print_address_func = print_address; +#if TARGET_BIG_ENDIAN + s->info.endian = BFD_ENDIAN_BIG; +#else + s->info.endian = BFD_ENDIAN_LITTLE; +#endif + + CPUClass *cc = CPU_GET_CLASS(cpu); + if (cc->disas_set_info) { + cc->disas_set_info(cpu, &s->info); + } +} + +static void initialize_debug_host(CPUDebug *s) +{ + initialize_debug(s); + + s->info.read_memory_func = host_read_memory; + s->info.print_address_func = host_print_address; +#if HOST_BIG_ENDIAN + s->info.endian = BFD_ENDIAN_BIG; +#else + s->info.endian = BFD_ENDIAN_LITTLE; +#endif +#if defined(CONFIG_TCG_INTERPRETER) + s->info.print_insn = print_insn_tci; +#elif defined(__i386__) + s->info.mach = bfd_mach_i386_i386; + s->info.cap_arch = CS_ARCH_X86; + s->info.cap_mode = CS_MODE_32; + s->info.cap_insn_unit = 1; + s->info.cap_insn_split = 8; +#elif defined(__x86_64__) + s->info.mach = bfd_mach_x86_64; + s->info.cap_arch = CS_ARCH_X86; + s->info.cap_mode = CS_MODE_64; + s->info.cap_insn_unit = 1; + s->info.cap_insn_split = 8; +#elif defined(_ARCH_PPC) + s->info.cap_arch = CS_ARCH_PPC; +# ifdef _ARCH_PPC64 + s->info.cap_mode = CS_MODE_64; +# endif +#elif defined(__riscv) && defined(CONFIG_RISCV_DIS) +#if defined(_ILP32) || (__riscv_xlen == 32) + s->info.print_insn = print_insn_riscv32; +#elif defined(_LP64) + s->info.print_insn = print_insn_riscv64; +#else +#error unsupported RISC-V ABI +#endif +#elif defined(__aarch64__) + s->info.cap_arch = CS_ARCH_ARM64; +#elif defined(__alpha__) + s->info.print_insn = print_insn_alpha; +#elif defined(__sparc__) + s->info.print_insn = print_insn_sparc; + s->info.mach = bfd_mach_sparc_v9b; +#elif defined(__arm__) + /* TCG only generates code for arm mode. */ + s->info.cap_arch = CS_ARCH_ARM; +#elif defined(__MIPSEB__) + s->info.print_insn = print_insn_big_mips; +#elif defined(__MIPSEL__) + s->info.print_insn = print_insn_little_mips; +#elif defined(__m68k__) + s->info.print_insn = print_insn_m68k; +#elif defined(__s390__) + s->info.cap_arch = CS_ARCH_SYSZ; + s->info.cap_insn_unit = 2; + s->info.cap_insn_split = 6; +#elif defined(__hppa__) + s->info.print_insn = print_insn_hppa; +#elif defined(__loongarch__) + s->info.print_insn = print_insn_loongarch; +#endif +} + +/* Disassemble this for me please... (debugging). */ +void target_disas(FILE *out, CPUState *cpu, target_ulong code, + target_ulong size) +{ + target_ulong pc; + int count; + CPUDebug s; + + initialize_debug_target(&s, cpu); + s.info.fprintf_func = fprintf; + s.info.stream = out; + s.info.buffer_vma = code; + s.info.buffer_length = size; + + if (s.info.cap_arch >= 0 && cap_disas_target(&s.info, code, size)) { + return; + } + + if (s.info.print_insn == NULL) { + s.info.print_insn = print_insn_od_target; + } + + for (pc = code; size > 0; pc += count, size -= count) { + fprintf(out, "0x" TARGET_FMT_lx ": ", pc); + count = s.info.print_insn(pc, &s.info); + fprintf(out, "\n"); + if (count < 0) { + break; + } + if (size < count) { + fprintf(out, + "Disassembler disagrees with translator over instruction " + "decoding\n" + "Please report this to qemu-devel@nongnu.org\n"); + break; + } + } +} + +static int G_GNUC_PRINTF(2, 3) +gstring_printf(FILE *stream, const char *fmt, ...) +{ + /* We abuse the FILE parameter to pass a GString. */ + GString *s = (GString *)stream; + int initial_len = s->len; + va_list va; + + va_start(va, fmt); + g_string_append_vprintf(s, fmt, va); + va_end(va); + + return s->len - initial_len; +} + +static void plugin_print_address(bfd_vma addr, struct disassemble_info *info) +{ + /* does nothing */ +} + + +/* + * We should only be dissembling one instruction at a time here. If + * there is left over it usually indicates the front end has read more + * bytes than it needed. + */ +char *plugin_disas(CPUState *cpu, uint64_t addr, size_t size) +{ + CPUDebug s; + GString *ds = g_string_new(NULL); + + initialize_debug_target(&s, cpu); + s.info.fprintf_func = gstring_printf; + s.info.stream = (FILE *)ds; /* abuse this slot */ + s.info.buffer_vma = addr; + s.info.buffer_length = size; + s.info.print_address_func = plugin_print_address; + + if (s.info.cap_arch >= 0 && cap_disas_plugin(&s.info, addr, size)) { + ; /* done */ + } else if (s.info.print_insn) { + s.info.print_insn(addr, &s.info); + } else { + ; /* cannot disassemble -- return empty string */ + } + + /* Return the buffer, freeing the GString container. */ + return g_string_free(ds, false); +} + +/* Disassemble this for me please... (debugging). */ +void disas(FILE *out, const void *code, unsigned long size) +{ + uintptr_t pc; + int count; + CPUDebug s; + + initialize_debug_host(&s); + s.info.fprintf_func = fprintf; + s.info.stream = out; + s.info.buffer = code; + s.info.buffer_vma = (uintptr_t)code; + s.info.buffer_length = size; + + if (s.info.cap_arch >= 0 && cap_disas_host(&s.info, code, size)) { + return; + } + + if (s.info.print_insn == NULL) { + s.info.print_insn = print_insn_od_host; + } + for (pc = (uintptr_t)code; size > 0; pc += count, size -= count) { + fprintf(out, "0x%08" PRIxPTR ": ", pc); + count = s.info.print_insn(pc, &s.info); + fprintf(out, "\n"); + if (count < 0) { + break; + } + } + +} + +/* Look up symbol for debugging purpose. Returns "" if unknown. */ +const char *lookup_symbol(target_ulong orig_addr) +{ + const char *symbol = ""; + struct syminfo *s; + + for (s = syminfos; s; s = s->next) { + symbol = s->lookup_symbol(s, orig_addr); + if (symbol[0] != '\0') { + break; + } + } + + return symbol; +} + +#if !defined(CONFIG_USER_ONLY) + +#include "monitor/monitor.h" + +static int +physical_read_memory(bfd_vma memaddr, bfd_byte *myaddr, int length, + struct disassemble_info *info) +{ + CPUDebug *s = container_of(info, CPUDebug, info); + MemTxResult res; + + res = address_space_read(s->cpu->as, memaddr, MEMTXATTRS_UNSPECIFIED, + myaddr, length); + return res == MEMTX_OK ? 0 : EIO; +} + +/* Disassembler for the monitor. */ +void monitor_disas(Monitor *mon, CPUState *cpu, + target_ulong pc, int nb_insn, int is_physical) +{ + int count, i; + CPUDebug s; + g_autoptr(GString) ds = g_string_new(""); + + initialize_debug_target(&s, cpu); + s.info.fprintf_func = gstring_printf; + s.info.stream = (FILE *)ds; /* abuse this slot */ + + if (is_physical) { + s.info.read_memory_func = physical_read_memory; + } + s.info.buffer_vma = pc; + + if (s.info.cap_arch >= 0 && cap_disas_monitor(&s.info, pc, nb_insn)) { + monitor_puts(mon, ds->str); + return; + } + + if (!s.info.print_insn) { + monitor_printf(mon, "0x" TARGET_FMT_lx + ": Asm output not supported on this arch\n", pc); + return; + } + + for (i = 0; i < nb_insn; i++) { + g_string_append_printf(ds, "0x" TARGET_FMT_lx ": ", pc); + count = s.info.print_insn(pc, &s.info); + g_string_append_c(ds, '\n'); + if (count < 0) { + break; + } + pc += count; + } + + monitor_puts(mon, ds->str); +} +#endif |