/* Copyright (C) 2004, 2005 Free Software Foundation. Ensure builtin __strncpy_chk performs correctly. */ 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 *strncpy (char *, const char *, size_t); extern int memcmp (const void *, const void *, size_t); extern int strcmp (const char *, const char *); extern int strncmp (const char *, const char *, size_t); extern void *memset (void *, int, size_t); #include "chk.h" const char s1[] = "123"; char p[32] = ""; char * volatile s2 = "defg"; /* prevent constant propagation to happen when whole program assumptions are made. */ char * volatile s3 = "FGH"; /* prevent constant propagation to happen when whole program assumptions are made. */ char *s4; volatile size_t l1 = 1; /* prevent constant propagation to happen when whole program assumptions are made. */ int i; void __attribute__((noinline)) test1 (void) { const char *const src = "hello world"; const char *src2; char dst[64], *dst2; strncpy_disallowed = 1; chk_calls = 0; memset (dst, 0, sizeof (dst)); if (strncpy (dst, src, 4) != dst || strncmp (dst, src, 4)) abort(); memset (dst, 0, sizeof (dst)); if (strncpy (dst+16, src, 4) != dst+16 || strncmp (dst+16, src, 4)) abort(); memset (dst, 0, sizeof (dst)); if (strncpy (dst+32, src+5, 4) != dst+32 || strncmp (dst+32, src+5, 4)) abort(); memset (dst, 0, sizeof (dst)); dst2 = dst; if (strncpy (++dst2, src+5, 4) != dst+1 || strncmp (dst2, src+5, 4) || dst2 != dst+1) abort(); memset (dst, 0, sizeof (dst)); if (strncpy (dst, src, 0) != dst || strcmp (dst, "")) abort(); memset (dst, 0, sizeof (dst)); dst2 = dst; src2 = src; if (strncpy (++dst2, ++src2, 0) != dst+1 || strcmp (dst2, "") || dst2 != dst+1 || src2 != src+1) abort(); memset (dst, 0, sizeof (dst)); dst2 = dst; src2 = src; if (strncpy (++dst2+5, ++src2+5, 0) != dst+6 || strcmp (dst2+5, "") || dst2 != dst+1 || src2 != src+1) abort(); memset (dst, 0, sizeof (dst)); if (strncpy (dst, src, 12) != dst || strcmp (dst, src)) abort(); /* Test at least one instance of the __builtin_ style. We do this to ensure that it works and that the prototype is correct. */ memset (dst, 0, sizeof (dst)); if (__builtin_strncpy (dst, src, 4) != dst || strncmp (dst, src, 4)) abort(); memset (dst, 0, sizeof (dst)); if (strncpy (dst, i++ ? "xfoo" + 1 : "bar", 4) != dst || strcmp (dst, "bar") || i != 1) abort (); if (chk_calls) abort (); strncpy_disallowed = 0; } void __attribute__((noinline)) test2 (void) { chk_calls = 0; /* No runtime checking should be done here, both destination and length are unknown. */ strncpy (s4, "abcd", l1 + 1); if (chk_calls) abort (); } /* Test whether compile time checking is done where it should and so is runtime object size checking. */ void __attribute__((noinline)) test3 (void) { struct A { char buf1[10]; char buf2[10]; } a; char *r = l1 == 1 ? &a.buf1[5] : &a.buf2[4]; char buf3[20]; int i; const char *l; size_t l2; /* The following calls should do runtime checking - source length is not known, but destination is. */ chk_calls = 0; strncpy (a.buf1 + 2, s3 + 3, l1); strncpy (r, s3 + 2, l1 + 2); r = l1 == 1 ? __builtin_alloca (4) : &a.buf2[7]; strncpy (r, s2 + 2, l1 + 2); strncpy (r + 2, s3 + 3, l1); r = buf3; for (i = 0; i < 4; ++i) { if (i == l1 - 1) r = &a.buf1[1]; else if (i == l1) r = &a.buf2[7]; else if (i == l1 + 1) r = &buf3[5]; else if (i == l1 + 2) r = &a.buf1[9]; } strncpy (r, s2 + 4, l1); if (chk_calls != 5) abort (); /* Following have known destination and known length, so if optimizing certainly shouldn't result in the checking variants. */ chk_calls = 0; strncpy (a.buf1 + 2, "", 3); strncpy (a.buf1 + 2, "", 0); strncpy (r, "a", 1); strncpy (r, "a", 3); r = l1 == 1 ? __builtin_alloca (4) : &a.buf2[7]; strncpy (r, s1 + 1, 3); strncpy (r, s1 + 1, 2); r = buf3; l = "abc"; l2 = 4; for (i = 0; i < 4; ++i) { if (i == l1 - 1) r = &a.buf1[1], l = "e", l2 = 2; else if (i == l1) r = &a.buf2[7], l = "gh", l2 = 3; else if (i == l1 + 1) r = &buf3[5], l = "jkl", l2 = 4; else if (i == l1 + 2) r = &a.buf1[9], l = "", l2 = 1; } strncpy (r, "", 1); /* Here, strlen (l) + 1 is known to be at most 4 and __builtin_object_size (&buf3[16], 0) is 4, so this doesn't need runtime checking. */ strncpy (&buf3[16], l, l2); strncpy (&buf3[15], "abc", l2); strncpy (&buf3[10], "fghij", l2); if (chk_calls) abort (); chk_calls = 0; } /* Test whether runtime and/or compile time checking catches buffer overflows. */ void __attribute__((noinline)) test4 (void) { struct A { char buf1[10]; char buf2[10]; } a; char buf3[20]; chk_fail_allowed = 1; /* Runtime checks. */ if (__builtin_setjmp (chk_fail_buf) == 0) { strncpy (&a.buf2[9], s2 + 4, l1 + 1); abort (); } if (__builtin_setjmp (chk_fail_buf) == 0) { strncpy (&a.buf2[7], s3, l1 + 4); abort (); } /* This should be detectable at compile time already. */ if (__builtin_setjmp (chk_fail_buf) == 0) { strncpy (&buf3[19], "abc", 2); abort (); } if (__builtin_setjmp (chk_fail_buf) == 0) { strncpy (&buf3[18], "", 3); 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)); test1 (); s4 = p; test2 (); test3 (); test4 (); }