zircon/system/ulib/pretty/hexdump.cc

// Copyright 2016 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <ctype.h>
#include <inttypes.h>
#include <lib/zircon-internal/align.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>

#include <pretty/hexdump.h>

#define MIN(a, b) (((a) < (b)) ? (a) : (b))

void hexdump_stdio_printf(void* printf_arg, const char* fmt, ...) {
  va_list args;
  va_start(args, fmt);
  vfprintf(static_cast<FILE*>(printf_arg), fmt, args);
  va_end(args);
}

// In the kernel, these are used in panic and debugging paths where the
// buffers passed might be suspect and it would be worse to get a sanitizer
// fault reading them than to display some garbage.  The other functions
// here (and their callees) have normal instrumentation since they don't
// derference pointers into the suspect buffer.
#if defined(__clang__) && _KERNEL
#define MAYBE_NO_ASAN [[clang::no_sanitize("address")]]
#else
#define MAYBE_NO_ASAN
#endif

MAYBE_NO_ASAN
void hexdump_very_ex(const void* ptr, size_t len, uint64_t disp_addr,
                     hexdump_printf_func_t* printf_func, void* printf_arg) {
  uintptr_t address = (uintptr_t)ptr;
  size_t count;

  for (count = 0; count < len; count += 16) {
    union {
      uint32_t buf[4];
      uint8_t cbuf[16];
    } u;
    size_t s = ZX_ROUNDUP(MIN(len - count, 16), 4);
    size_t i;

    printf_func(printf_arg,
                ((disp_addr + len) > 0xFFFFFFFF ? "0x%016" PRIx64 ": " : "0x%08" PRIx64 ": "),
                disp_addr + count);

    for (i = 0; i < s / 4; i++) {
      u.buf[i] = ((const uint32_t*)address)[i];
      printf_func(printf_arg, "%08x ", static_cast<unsigned int>(u.buf[i]));
    }
    for (; i < 4; i++) {
      printf_func(printf_arg, "         ");
    }
    printf_func(printf_arg, "|");

    for (i = 0; i < 16; i++) {
      char c = u.cbuf[i];
      if (i < s && isprint(c)) {
        printf_func(printf_arg, "%c", c);
      } else {
        printf_func(printf_arg, ".");
      }
    }
    printf_func(printf_arg, "|\n");
    address += 16;
  }
}

MAYBE_NO_ASAN
void hexdump8_very_ex(const void* ptr, size_t len, uint64_t disp_addr,
                      hexdump_printf_func_t* printf_func, void* printf_arg) {
  uintptr_t address = (uintptr_t)ptr;
  size_t count;
  size_t i;

  for (count = 0; count < len; count += 16) {
    printf_func(printf_arg,
                ((disp_addr + len) > 0xFFFFFFFF ? "0x%016" PRIx64 ": " : "0x%08" PRIx64 ": "),
                disp_addr + count);

    for (i = 0; i < MIN(len - count, 16); i++) {
      printf_func(printf_arg, "%02hhx ", *(const uint8_t*)(address + i));
    }

    for (; i < 16; i++) {
      printf_func(printf_arg, "   ");
    }

    printf_func(printf_arg, "|");

    for (i = 0; i < MIN(len - count, 16); i++) {
      char c = ((const char*)address)[i];
      printf_func(printf_arg, "%c", isprint(c) ? c : '.');
    }

    printf_func(printf_arg, "\n");
    address += 16;
  }
}

void hexdump_ex(const void* ptr, size_t len, uint64_t disp_addr) {
  hexdump_very_ex(ptr, len, disp_addr, hexdump_stdio_printf, stdout);
}

void hexdump8_ex(const void* ptr, size_t len, uint64_t disp_addr) {
  hexdump8_very_ex(ptr, len, disp_addr, hexdump_stdio_printf, stdout);
}