On 5/13/06, Shriramana Sharma <samjnaa@xxxxxxxxx> wrote:
Saturday 13 May 2006 20:39 samaye, Steve Graegert alekhiit:
> Looks like the function 'listsplpanchaanga' tries to access the
> 'grahanaama' array's nth element with only n - 1 being present
> ('vaasara = 6' accesses the last, 7th, element),
Yep. But the array does contain 7 elements. Vide line 64 of monthpan.c:
Sure, but valgrind's output shows, that the program tries to read the
first character of the nth element: "Invalid read of size 1" (with
char of size 1).
Furthermore it shows that the error occurs in the same loop in function:
/* called from within main */
==9675== by 0x8049AD0: listsplpanchaanga (monthpan.c:512)
==9675== by 0x804AC67: main (monthpan.c:148)
[debug output here and still within listsplpanchaanga()]
==9675== Invalid read of size 1
==9675== at 0x4021FB8: strlen (in
/usr/lib/valgrind/x86-linux/vgpreload_memcheck.so)
==9675== by 0x40A0807: vfprintf (in /lib/libc-2.4.so)
==9675== by 0x40A5C92: printf (in /lib/libc-2.4.so)
==9675== by 0x8049B7D: listsplpanchaanga (monthpan.c:593)
==9675== by 0x804AC67: main (monthpan.c:148)
==9675== Address 0x726956 is not stack'd, malloc'd or (recently) free'
This reads as: main() calls listsplpanchaanga() calls printf() calls
vfprintf() calls strlen() where the read failed. In line 593 printf()
tries to read a byte which is neither on the stack, the heap nor has
been free()'d.
[snip]
vaasara[6] does give the correct output. The fault is seen *after* vaasara[6]
is read and written to stdout:
which accesses the last element correctly. Nevertheless, the function
tries to read one more character causing a segfault. Please don't
misinterpret valgind's output: we are still in listsplpanchaanga().
> step in the loop. Maybe you can simply correct the error by accessing
> 'grahanaama' using 'vaasara - 1': grahanaama[vaasara - 1] if this is
> what you wanted to achieve.
But then I would not get grahanaama[0] = "Surya" which is what I want to get.
Actually this program compiled and worked perfectly on GCC 4.02 with SUSE
10.0. (And also GCC 4.1 with SUSE 10.0 I think.) But since I upgraded to SUSE
10.1, I get this error. SUSE 10.1 has gcc 4.1 and glibc 2.4, [as I am sure
you as a fellow suser know] if that means anything...
Hm, don't know what could have changed. I am not a SuSEr anymore;
returned to Debian and NetBSD.
> At least, this is my first guess. I have not yet fully grasped the
> meaning of the code, due to difficulties in understanding the variable
> and function names :-)
Sanskrit. It's an ancient-Indian-astronomy application.
Hey cool! My girlfriend is a Buddhist, she may indeed have some
knowledge of Sanskrit, but I have serious doubts that she is willing
to read the code :-)
\Steve
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