vsnprintf-chk.c

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/* Copyright (C) 2004, 2005  Free Software Foundation.

   Ensure builtin __vsnprintf_chk performs correctly.  */

#include <stdarg.h>

extern void abort (void);
typedef __SIZE_TYPE__ size_t;
extern size_t strlen(const char *);
extern void *memcpy (void *, const void *, size_t);
extern char *strcpy (char *, const char *);
extern int memcmp (const void *, const void *, size_t);
extern void *memset (void *, int, size_t);
extern int vsnprintf (char *, size_t, const char *, va_list);

#include "chk.h"

const char s1[] = "123";
char p[32] = "";
char *s2 = "defg";
char *s3 = "FGH";
char *s4;
size_t l1 = 1;
static char buffer[32];
char *ptr = "barf";

int
__attribute__((noinline))
test1_sub (int i, ...)
{
  int ret = 0;
  va_list ap;
  va_start (ap, i);
  switch (i)
    {
    case 0:
      vsnprintf (buffer, 4, "foo", ap);
      break;
    case 1:
      ret = vsnprintf (buffer, 4, "foo bar", ap);
      break;
    case 2:
      vsnprintf (buffer, 32, "%s", ap);
      break;
    case 3:
      ret = vsnprintf (buffer, 21, "%s", ap);
      break;
    case 4:
      ret = vsnprintf (buffer, 4, "%d%d%d", ap);
      break;
    case 5:
      ret = vsnprintf (buffer, 32, "%d%d%d", ap);
      break;
    case 6:
      ret = vsnprintf (buffer, strlen (ptr) + 1, "%s", ap);
      break;
    case 7:
      vsnprintf (buffer, l1 + 31, "%d - %c", ap);
      break;
    case 8:
      vsnprintf (s4, l1 + 6, "%d - %c", ap);
      break;
    }
  va_end (ap);
  return ret;
}

void
__attribute__((noinline))
test1 (void)
{
  chk_calls = 0;
  /* vsnprintf_disallowed = 1; */

  memset (buffer, 'A', 32);
  test1_sub (0);
  if (memcmp (buffer, "foo", 4) || buffer[4] != 'A')
    abort ();

  memset (buffer, 'A', 32);
  if (test1_sub (1) != 7)
    abort ();
  if (memcmp (buffer, "foo", 4) || buffer[4] != 'A')
    abort ();

  vsnprintf_disallowed = 0;

  memset (buffer, 'A', 32);
  test1_sub (2, "bar");
  if (memcmp (buffer, "bar", 4) || buffer[4] != 'A')
    abort ();

  memset (buffer, 'A', 32);
  if (test1_sub (3, "bar") != 3)
    abort ();
  if (memcmp (buffer, "bar", 4) || buffer[4] != 'A')
    abort ();

  memset (buffer, 'A', 32);
  if (test1_sub (4, (int) l1, (int) l1 + 1, (int) l1 + 12) != 4)
    abort ();
  if (memcmp (buffer, "121", 4) || buffer[4] != 'A')
    abort ();

  memset (buffer, 'A', 32);
  if (test1_sub (5, (int) l1, (int) l1 + 1, (int) l1 + 12) != 4)
    abort ();
  if (memcmp (buffer, "1213", 5) || buffer[5] != 'A')
    abort ();

  if (chk_calls)
    abort ();

  memset (buffer, 'A', 32);
  test1_sub (6, ptr);
  if (memcmp (buffer, "barf", 5) || buffer[5] != 'A')
    abort ();

  memset (buffer, 'A', 32);
  test1_sub (7, (int) l1 + 27, *ptr);
  if (memcmp (buffer, "28 - b\0AAAAA", 12))
    abort ();

  if (chk_calls != 2)
    abort ();
  chk_calls = 0;

  memset (s4, 'A', 32);
  test1_sub (8, (int) l1 - 17, ptr[1]);
  if (memcmp (s4, "-16 - \0AAA", 10))
    abort ();
  if (chk_calls)
    abort ();
}

void
__attribute__((noinline))
test2_sub (int i, ...)
{
  va_list ap;
  struct A { char buf1[10]; char buf2[10]; } a;
  char *r = l1 == 1 ? &a.buf1[5] : &a.buf2[4];
  char buf3[20];
  int j;

  va_start (ap, i);
  /* The following calls should do runtime checking
     - length is not known, but destination is.  */
  switch (i)
    {
    case 0:
      vsnprintf (a.buf1 + 2, l1, "%s", ap);
      break;
    case 1:
      vsnprintf (r, l1 + 4, "%s%c", ap);
      break;
    case 2:
      r = l1 == 1 ? __builtin_alloca (4) : &a.buf2[7];
      vsnprintf (r, strlen (s2) - 2, "%c %s", ap);
      break;
    case 3:
      r = l1 == 1 ? __builtin_alloca (4) : &a.buf2[7];
      vsnprintf (r + 2, l1, s3 + 3, ap);
      break;
    case 4:
    case 7:
      r = buf3;
      for (j = 0; j < 4; ++j)
	{
	  if (j == l1 - 1)
	    r = &a.buf1[1];
	  else if (j == l1)
	    r = &a.buf2[7];
	  else if (j == l1 + 1)
	    r = &buf3[5];
	  else if (j == l1 + 2)
	    r = &a.buf1[9];
	}
      if (i == 4)
	vsnprintf (r, l1, s2 + 4, ap);
      else
	vsnprintf (r, 1, "a", ap);
      break;
    case 5:
      r = l1 == 1 ? __builtin_alloca (4) : &a.buf2[7];
      vsnprintf (r, l1 + 3, "%s", ap);
      break;
    case 6:
      vsnprintf (a.buf1 + 2, 4, "", ap);
      break;
    case 8:
      vsnprintf (s4, 3, "%s %d", ap);
      break;
    }
  va_end (ap);
}

/* Test whether compile time checking is done where it should
   and so is runtime object size checking.  */
void
__attribute__((noinline))
test2 (void)
{
  /* The following calls should do runtime checking
     - length is not known, but destination is.  */
  chk_calls = 0;
  test2_sub (0, s3 + 3);
  test2_sub (1, s3 + 3, s3[3]);
  test2_sub (2, s2[2], s2 + 4);
  test2_sub (3);
  test2_sub (4);
  test2_sub (5, s1 + 1);
  if (chk_calls != 6)
    abort ();

  /* Following have known destination and known source length,
     so if optimizing certainly shouldn't result in the checking
     variants.  */
  chk_calls = 0;
  /* vsnprintf_disallowed = 1; */
  test2_sub (6);
  test2_sub (7);
  vsnprintf_disallowed = 0;
  /* Unknown destination and source, no checking.  */
  test2_sub (8, s3, 0);
  if (chk_calls)
    abort ();
}

void
__attribute__((noinline))
test3_sub (int i, ...)
{
  va_list ap;
  struct A { char buf1[10]; char buf2[10]; } a;
  char buf3[20];

  va_start (ap, i);
  /* The following calls should do runtime checking
     - source length is not known, but destination is.  */
  switch (i)
    {
    case 0:
      vsnprintf (&a.buf2[9], l1 + 1, "%c%s", ap);
      break;
    case 1:
      vsnprintf (&a.buf2[7], l1 + 30, "%s%c", ap);
      break;
    case 2:
      vsnprintf (&a.buf2[7], l1 + 3, "%d", ap);
      break;
    case 3:
      vsnprintf (&buf3[17], l1 + 3, "%s", ap);
      break;
    case 4:
      vsnprintf (&buf3[19], 2, "a", ap);
      break;
    case 5:
      vsnprintf (&buf3[16], 5, "a", ap);
      break;
    }
  va_end (ap);
}

/* Test whether runtime and/or compile time checking catches
   buffer overflows.  */
void
__attribute__((noinline))
test3 (void)
{
  chk_fail_allowed = 1;
  /* Runtime checks.  */
  if (__builtin_setjmp (chk_fail_buf) == 0)
    {
      test3_sub (0, s2[3], s2 + 4);
      abort ();
    }
  if (__builtin_setjmp (chk_fail_buf) == 0)
    {
      test3_sub (1, s3 + strlen (s3) - 2, *s3);
      abort ();
    }
  if (__builtin_setjmp (chk_fail_buf) == 0)
    {
      test3_sub (2, (int) l1 + 9999);
      abort ();
    }
  if (__builtin_setjmp (chk_fail_buf) == 0)
    {
      test3_sub (3, "abc");
      abort ();
    }
  /* This should be detectable at compile time already.  */
  if (__builtin_setjmp (chk_fail_buf) == 0)
    {
      test3_sub (4);
      abort ();
    }
  if (__builtin_setjmp (chk_fail_buf) == 0)
    {
      test3_sub (5);
      abort ();
    }
  chk_fail_allowed = 0;
}

void
main_test (void)
{
#ifndef __OPTIMIZE__
  /* Object size checking is only intended for -O[s123].  */
  return;
#endif
  __asm ("" : "=r" (s2) : "0" (s2));
  __asm ("" : "=r" (s3) : "0" (s3));
  __asm ("" : "=r" (l1) : "0" (l1));
  s4 = p;
  test1 ();
  test2 ();
  test3 ();
}