[Bug c/35347] New: Return of static causes segfault

[Bug c/35347] New: Return of static causes segfault

[rkies at cpan dot org]

Apologies if this has been reported before.  I've encountered this behavior in
a test script.

System info (output of uname -a):
Linux opti1 2.6.18-5-686 #1 SMP Mon Dec 24 16:41:07 UTC 2007 i686 GNU/Linux

Output of gcc -v --save-temps...
rkiesling@opti1:~$ gcc -v -save-temps static-strcpy-bug.c
Reading specs from /usr/lib/gcc-lib/i486-linux-gnu/3.3.6/specs
Configured with: ../src/configure -v --enable-languages=c,c++ --prefix=/usr
--mandir=/usr/share/man --infodir=/usr/share/info
--with-gxx-include-dir=/usr/include/c++/3.3 --enable-shared
--enable-__cxa_atexit --with-system-zlib --enable-nls
--without-included-gettext --enable-clocale=gnu --enable-debug i486-linux-gnu
Thread model: posix
gcc version 3.3.6 (Debian 1:3.3.6-15)
 /usr/lib/gcc-lib/i486-linux-gnu/3.3.6/cc1 -E -quiet -v -D__GNUC__=3
-D__GNUC_MINOR__=3 -D__GNUC_PATCHLEVEL__=6 static-strcpy-bug.c
static-strcpy-bug.i
ignoring nonexistent directory "/usr/local/include/i486-linux-gnu"
ignoring nonexistent directory "/usr/i486-linux-gnu/include"
ignoring nonexistent directory "/usr/include/i486-linux-gnu"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include
 /usr/lib/gcc-lib/i486-linux-gnu/3.3.6/include
 /usr/include
End of search list.
 /usr/lib/gcc-lib/i486-linux-gnu/3.3.6/cc1 -fpreprocessed static-strcpy-bug.i
-quiet -dumpbase static-strcpy-bug.c -auxbase static-strcpy-bug -version -o
static-strcpy-bug.s
GNU C version 3.3.6 (Debian 1:3.3.6-15) (i486-linux-gnu)
        compiled by GNU C version 3.3.6 (Debian 1:3.3.6-15).
GGC heuristics: --param ggc-min-expand=47 --param ggc-min-heapsize=31870
 as -V -Qy -o static-strcpy-bug.o static-strcpy-bug.s
GNU assembler version 2.17 (i486-linux-gnu) using BFD version 2.17 Debian
GNU/Linux
 /usr/lib/gcc-lib/i486-linux-gnu/3.3.6/collect2 --eh-frame-hdr -m elf_i386
-dynamic-linker /lib/ld-linux.so.2
/usr/lib/gcc-lib/i486-linux-gnu/3.3.6/../../../crt1.o
/usr/lib/gcc-lib/i486-linux-gnu/3.3.6/../../../crti.o
/usr/lib/gcc-lib/i486-linux-gnu/3.3.6/crtbegin.o
-L/usr/lib/gcc-lib/i486-linux-gnu/3.3.6
-L/usr/lib/gcc-lib/i486-linux-gnu/3.3.6/../../.. static-strcpy-bug.o -lgcc
--as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed
/usr/lib/gcc-lib/i486-linux-gnu/3.3.6/crtend.o
/usr/lib/gcc-lib/i486-linux-gnu/3.3.6/../../../crtn.o

Source of static-strcpy-bug.i:

# 1 "static-strcpy-bug.c"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "static-strcpy-bug.c"
# 1 "/usr/include/string.h" 1 3 4
# 26 "/usr/include/string.h" 3 4
# 1 "/usr/include/features.h" 1 3 4
# 308 "/usr/include/features.h" 3 4
# 1 "/usr/include/sys/cdefs.h" 1 3 4
# 309 "/usr/include/features.h" 2 3 4
# 331 "/usr/include/features.h" 3 4
# 1 "/usr/include/gnu/stubs.h" 1 3 4
# 332 "/usr/include/features.h" 2 3 4
# 27 "/usr/include/string.h" 2 3 4






# 1 "/usr/lib/gcc-lib/i486-linux-gnu/3.3.6/include/stddef.h" 1 3 4
# 213 "/usr/lib/gcc-lib/i486-linux-gnu/3.3.6/include/stddef.h" 3 4
typedef unsigned int size_t;
# 34 "/usr/include/string.h" 2 3 4




extern void *memcpy (void *__restrict __dest,
                     __const void *__restrict __src, size_t __n)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2)));


extern void *memmove (void *__dest, __const void *__src, size_t __n)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2)));






extern void *memccpy (void *__restrict __dest, __const void *__restrict __src,
                      int __c, size_t __n)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2)));





extern void *memset (void *__s, int __c, size_t __n) __attribute__
((__nothrow__)) __attri
bute__ ((__nonnull__ (1)));


extern int memcmp (__const void *__s1, __const void *__s2, size_t __n)
     __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__
((__nonnull__ 
(1, 2)));


extern void *memchr (__const void *__s, int __c, size_t __n)
      __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__
((__nonnull__
 (1)));

# 82 "/usr/include/string.h" 3 4


extern char *strcpy (char *__restrict __dest, __const char *__restrict __src)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2)));

extern char *strncpy (char *__restrict __dest,
                      __const char *__restrict __src, size_t __n)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2)));


extern char *strcat (char *__restrict __dest, __const char *__restrict __src)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2)));

extern char *strncat (char *__restrict __dest, __const char *__restrict __src,
                      size_t __n) __attribute__ ((__nothrow__)) __attribute__
((__nonnull_
(1, 2)));

extern int strncmp (__const char *__s1, __const char *__s2, size_t __n)
     __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__
((__nonnull__ 
(1, 2)));


extern int strcoll (__const char *__s1, __const char *__s2)
     __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__
((__nonnull__ 
(1, 2)));

extern size_t strxfrm (char *__restrict __dest,
                       __const char *__restrict __src, size_t __n)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (2)));

# 130 "/usr/include/string.h" 3 4
extern char *strdup (__const char *__s)
     __attribute__ ((__nothrow__)) __attribute__ ((__malloc__)) __attribute__
((__nonnull_
_ (1)));
# 165 "/usr/include/string.h" 3 4


extern char *strchr (__const char *__s, int __c)
     __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__
((__nonnull__ 
(1)));

extern char *strrchr (__const char *__s, int __c)
     __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__
((__nonnull__ 
(1)));

# 181 "/usr/include/string.h" 3 4

extern size_t strcspn (__const char *__s, __const char *__reject)
     __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__
((__nonnull__ 
(1, 2)));


extern size_t strspn (__const char *__s, __const char *__accept)
     __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__
((__nonnull__ 
(1, 2)));

extern char *strpbrk (__const char *__s, __const char *__accept)
     __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__
((__nonnull__ 
(1, 2)));

extern char *strstr (__const char *__haystack, __const char *__needle)
     __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__
((__nonnull__ 
(1, 2)));



extern char *strtok (char *__restrict __s, __const char *__restrict __delim)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (2)));




extern char *__strtok_r (char *__restrict __s,
                         __const char *__restrict __delim,
                         char **__restrict __save_ptr)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (2, 3)));

extern char *strtok_r (char *__restrict __s, __const char *__restrict __delim,
                       char **__restrict __save_ptr)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (2, 3)));
# 240 "/usr/include/string.h" 3 4


extern size_t strlen (__const char *__s)
     __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__
((__nonnull__ 
(1)));

# 254 "/usr/include/string.h" 3 4


extern char *strerror (int __errnum) __attribute__ ((__nothrow__));

# 281 "/usr/include/string.h" 3 4
extern char *strerror_r (int __errnum, char *__buf, size_t __buflen)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (2)));





extern void __bzero (void *__s, size_t __n) __attribute__ ((__nothrow__))
__attribute__ ((
__nonnull__ (1)));



extern void bcopy (__const void *__src, void *__dest, size_t __n)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2)));


extern void bzero (void *__s, size_t __n) __attribute__ ((__nothrow__))
__attribute__ ((__
nonnull__ (1)));


extern int bcmp (__const void *__s1, __const void *__s2, size_t __n)
     __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__
((__nonnull__ 
(1, 2)));


extern char *index (__const char *__s, int __c)
     __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__
((__nonnull__ 
(1)));


extern char *rindex (__const char *__s, int __c)
     __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__
((__nonnull__ 
(1)));


extern char *rindex (__const char *__s, int __c)
     __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__
((__nonnull__ 
(1)));



extern int ffs (int __i) __attribute__ ((__nothrow__)) __attribute__
((__const__));
# 325 "/usr/include/string.h" 3 4
extern int strcasecmp (__const char *__s1, __const char *__s2)
     __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__
((__nonnull__ 
(1, 2)));


extern int strncasecmp (__const char *__s1, __const char *__s2, size_t __n)
     __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__
((__nonnull__ 
(1, 2)));
# 348 "/usr/include/string.h" 3 4
extern char *strsep (char **__restrict __stringp,
                     __const char *__restrict __delim)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2)));
# 426 "/usr/include/string.h" 3 4

# 2 "static-strcpy-bug.c" 2

char *str1 (void) {
  static char *s = "Hello, world!\n";
  return s;
}

int main () {

  char str2[255];

  strcpy (str1 (), str2);
  exit (0);
}

Output of GDB:

rkiesling@opti1:~$ gdb a.out
GNU gdb 6.6
Copyright (C) 2006 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i686-pc-linux-gnu"...
Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1".
(gdb) r
Starting program: /home/rkiesling/a.out -P test.c -o test.i
Failed to read a valid object file image from memory.

Program received signal SIGSEGV, Segmentation fault.
0xb7e73f43 in strcpy () from /lib/tls/i686/cmov/libc.so.6
(gdb) backtrace
#0  0xb7e73f43 in strcpy () from /lib/tls/i686/cmov/libc.so.6
#1  0x080483ea in main ()
(gdb)


-- 
           Summary: Return of static causes segfault
           Product: gcc
           Version: 3.3.6
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rkies at cpan dot org
 GCC build triplet: i486-linux-gnu
  GCC host triplet: i486-linux-gnu
GCC target triplet: i486-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35347

[Bug c/35347] Return of static causes segfault

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2008-02-24 07:28 -------
This is correct behavior, a string literal is constant data so you are
returning a pointer to a constant data which then you are trying to copy into.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35347