Public bug reported:
Under gcc 4.1.1-6ubuntu3 and both Linux 2.6.17-11-386 and Linux
2.6.17.14-ubuntu1-systemtap, the address of argc is changing when
certain functions are called. When printf()s that reference argc are
interleaved with the offending code, the error disappears. Binaries
compiled with this version of gcc continue to have this problem on other
Linux distributions (eg FC5). All of this testing is on the i386
architecture.
Example:
...
server_socket = socket(AF_INET, SOCK_STREAM, 0);
// argc = 1
bind(server_socket, (struct sockaddr *) &server_addr,
sizeof(server_addr)); // argc = 2 ??
listen(server_socket, LISTEN_BACKLOG);
size_client_addr = sizeof(client_addr);
...
gdb output: (showing change)
Breakpoint 1, main (argc=1, argv=0xbfba78a4) at server.c:107
107 server_socket = socket(AF_INET, SOCK_STREAM, 0);
(gdb) c
Continuing.
Breakpoint 2, main (argc=2, argv=0xbfba78a4) at server.c:108
108 bind(server_socket, (struct sockaddr *) &server_addr,
...
gdb output (showing address change):
(gdb) b 107
Breakpoint 1 at 0x80487c1: file server.c, line 107.
(gdb) b 108
Breakpoint 2 at 0x80487e0: file server.c, line 108.
(gdb) c
The program is not being run.
(gdb) r
Starting program: /home/me/tmp/HiRCServer
Breakpoint 1, main (argc=1, argv=0xbfe14b14) at server.c:107
107 server_socket = socket(AF_INET, SOCK_STREAM, 0);
(gdb) p &argc
$1 = (const int *) 0xbfe14a90
(gdb) c
Continuing.
Breakpoint 2, main (argc=2, argv=0xbfe14b14) at server.c:108
108 bind(server_socket, (struct sockaddr *) &server_addr,
(gdb) p &argc
$2 = (const int *) 0xbfe03e10
----
This condition does not appear itself with gcc 4.1.1 on Fedora Core 5 or gcc
3.4.3 under Solaris Express.
Screenshots, binaries, and code causing this issue:
http://acm.jhu.edu/~me/gcc-ubuntu-edgy/
** Affects: gcc-defaults (Ubuntu)
Importance: Undecided
Status: Unconfirmed
--
Address of argc changes when certain functions are called.
https://launchpad.net/bugs/84926
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