disas: Move disas.c to disas/

Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230503072331.1747057-80-richard.henderson@linaro.org>

2 files changed, 402 insertions, 1 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
diff --git a/disas/meson.build b/disas/meson.build
index c865bdd882..cbf6315f25 100644
--- a/disas/meson.build
+++ b/disas/meson.build
@@ -10,4 +10,6 @@ common_ss.add(when: 'CONFIG_RISCV_DIS', if_true: files('riscv.c'))
 common_ss.add(when: 'CONFIG_SH4_DIS', if_true: files('sh4.c'))
 common_ss.add(when: 'CONFIG_SPARC_DIS', if_true: files('sparc.c'))
 common_ss.add(when: 'CONFIG_XTENSA_DIS', if_true: files('xtensa.c'))
-common_ss.add(when: capstone, if_true: files('capstone.c'))
+common_ss.add(when: capstone, if_true: [files('capstone.c'), capstone])
+
+specific_ss.add(files('disas.c'), capstone)