Bug in SosMan's getline_test
- From: Friar Tuck <nospam@xxxxxxxxxxx>
- Date: Wed, 12 Sep 2007 00:58:05 +0200 (CEST)
I believe I have found a bug in Dr Sosman's getline_test program, which
is one of the official newsgroup programs. Debugging information
follows.
$ gdb ./getline_test
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This GDB was configured as "i586-suse-linux"...Using host libthread_db library
"/lib/tls/libthread_db.so.1".
(gdb) r
Starting program: /tmp/getline_test
Program received signal SIGSEGV, Segmentation fault.
0x4008febf in getdelim () from /lib/tls/libc.so.6
(gdb) bt
#0 0x4008febf in getdelim () from /lib/tls/libc.so.6
#1 0x4008d844 in getline () from /lib/tls/libc.so.6
#2 0x080486b2 in verify (file=0x804a008, st=0xbfffee70, special=0) at
getline_test.c:44
#3 0x0804891d in main () at getline_test.c:103
(gdb) f 2
#2 0x080486b2 in verify (file=0x804a008, st=0xbfffee70, special=0) at
getline_test.c:44
44 buff = getline(file);
(gdb) p *file
$1 = {_flags = -72539008,
_IO_read_ptr = 0x40018000 'n' <repeats 25 times>, "\n", 'd' <repeats 174 times>...,
_IO_read_end = 0x40018000 'n' <repeats 25 times>, "\n", 'd' <repeats 174 times>...,
_IO_read_base = 0x40018000 'n' <repeats 25 times>, "\n", 'd' <repeats 174 times>...,
_IO_write_base = 0x40018000 'n' <repeats 25 times>, "\n", 'd' <repeats 174 times>...,
_IO_write_ptr = 0x40018000 'n' <repeats 25 times>, "\n", 'd' <repeats 174 times>...,
_IO_write_end = 0x40018000 'n' <repeats 25 times>, "\n", 'd' <repeats 174 times>...,
_IO_buf_base = 0x40018000 'n' <repeats 25 times>, "\n", 'd' <repeats 174 times>...,
_IO_buf_end = 0x40019000 'b' <repeats 200 times>...,
_IO_save_base = 0x0,
_IO_backup_base = 0x0, _IO_save_end = 0x0, _markers = 0x0,
_chain = 0x40151460,
_fileno = 6, _flags2 = 0, _old_offset = 0, _cur_column = 0,
_vtable_offset = 0 '\0',
_shortbuf = "", _lock = 0x804a0a0, _offset = 0, __pad1 =
0x0, __pad2 = 0x804a0ac,
_mode = -1, _unused2 = '\0' <repeats 51 times>}
(gdb)
It looks to me like the _flags field of file has become corrupted - it
seems to have an odd value.
.
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