There is an error found in gdb that produces segfault if some conditions meet. The bug exists at last in the last stable gdb version sys-devel/gdb-6.3-r4 and in previous sys-devel/gdb-6.3-r3. It is reproducable at two different Gentoo Linux installs on two different boxes. Here is the steps to reproduce the segfault in gdb: 1) $ cp /etc/skel/.gdbinit 2) Launch gdb: $ gdb 3) Try command like "help t" in gdb: gdb> help t After all this steps gdb catches segfault. spiritus@gentoo ~ $ ulimit -c unlimited spiritus@gentoo ~ $ gdb GNU gdb 6.3 Copyright 2004 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". gdb> help t Segmentation fault (core dumped) The segfault doesn't appear if there is no .gdbinit in home directory. So it seems that the bug may be in the config parsing code. Here is the backtrace: spiritus@gentoo ~ $ gdb /usr/bin/gdb -c core GNU gdb 6.3 Copyright 2004 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/libthread_db.so.1". Core was generated by `gdb'. Program terminated with signal 11, Segmentation fault. warning: current_sos: Can't read pathname for load map: Input/output error Reading symbols from /lib/libreadline.so.5...done. Loaded symbols for /lib/libreadline.so.5 Reading symbols from /lib/libncurses.so.5...done. Loaded symbols for /lib/libncurses.so.5 Reading symbols from /lib/tls/libm.so.6...done. Loaded symbols for /lib/tls/libm.so.6 Reading symbols from /lib/libdl.so.2...done. Loaded symbols for /lib/libdl.so.2 Reading symbols from /lib/tls/libc.so.6...done. Loaded symbols for /lib/tls/libc.so.6 Reading symbols from /lib/libgpm.so.1...done. Loaded symbols for /lib/libgpm.so.1 Reading symbols from /lib/ld-linux.so.2...done. Loaded symbols for /lib/ld-linux.so.2 Reading symbols from /lib/tls/libthread_db.so.1...done. Loaded symbols for /lib/tls/libthread_db.so.1 Reading symbols from /lib/libthread_db.so.1...done. Loaded symbols for /lib/libthread_db.so.1 #0 0x080b60fc in lookup_cmd_1 (text=0xbfffdfc0, clist=0x8317088, result_list=0xbfffdf8c, ignore_help_classes=0x0) at cli-decode.c:1077 1077 c = lookup_cmd_1 (text, *found->prefixlist, result_list, gdb> bt #0 0x080b60fc in lookup_cmd_1 (text=0xbfffdfc0, clist=0x8317088, result_list=0xbfffdf8c, ignore_help_classes=0x0) at cli-decode.c:1077 #1 0x080b61fa in lookup_cmd (line=0xbfffdfc0, list=0x8317088, cmdtype=0x824fae0 "", allow_unknown=0x0, ignore_help_classes=0x0) at cli-decode.c:1146 #2 0x080b57fc in help_cmd (command=0x82e67b6 "", stream=0x831eae8) at cli-decode.c:717 #3 0x080b8ced in help_command (command=0x82e67b5 "t", from_tty=0x0) at cli-cmds.c:214 #4 0x080b4993 in do_cfunc (c=0x831bac0, args=0x82e67b5 "t", from_tty=0x0) at cli-decode.c:57 #5 0x080b6ddc in cmd_func (cmd=0x831bac0, args=0x82e67b5 "t", from_tty=0x0) at cli-decode.c:1599 #6 0x0807e86a in execute_command (p=0x82e67b5 "t", from_tty=0x1) at top.c:733 #7 0x081220ca in command_handler (command=0x82e67b0 "help t") at event-top.c:500 #8 0x08122880 in command_line_handler (rl=0x831e0c8 "0н1\b@н1\b") at event-top.c:793 #9 0xb7fc513f in rl_callback_read_char () from /lib/libreadline.so.5 #10 0x08121833 in rl_callback_read_char_wrapper (client_data=0x0) at event-top.c:166 #11 0x08121f8d in stdin_event_handler (error=0x0, client_data=0x0) at event-top.c:416 #12 0x08120f6f in handle_file_event (event_file_desc=0x0) at event-loop.c:721 #13 0x08120869 in process_event () at event-loop.c:334 #14 0x081208b2 in gdb_do_one_event (data=0x0) at event-loop.c:371 #15 0x0807e4c8 in do_catch_errors (uiout=0x831def8, data=0xbfffe298) at top.c:524 #16 0x0807e26c in catcher (func=0x807e4ac <do_catch_errors>, func_uiout=0x831def8, func_args=0xbfffe298, func_val=0xbfffe2a4, func_caught=0xbfffe2a0, errstring=0x8255809 "", gdberrmsg=0x0, mask=0x6) at top.c:431 #17 0x0807e51c in catch_errors (func=0x812087e <gdb_do_one_event>, func_args=0x0, errstring=0x8255809 "", mask=0x6) at top.c:536 #18 0x080c45e8 in tui_command_loop (data=0x0) at tui-interp.c:150 #19 0x0811e227 in current_interp_command_loop () at interps.c:277 #20 0x08074943 in captured_command_loop (data=0x0) at main.c:91 #21 0x0807e4c8 in do_catch_errors (uiout=0x831def8, data=0xbfffe438) at top.c:524 #22 0x0807e26c in catcher (func=0x807e4ac <do_catch_errors>, func_uiout=0x831def8, func_args=0xbfffe438, func_val=0xbfffe444, func_caught=0xbfffe440, errstring=0x823bd9a "", gdberrmsg=0x0, mask=0x6) at top.c:431 #23 0x0807e51c in catch_errors (func=0x8074938 <captured_command_loop>, func_args=0x0, errstring=0x823bd9a "", mask=0x6) at top.c:536 #24 0x08075819 in captured_main (data=0xbfffe750) at main.c:801 #25 0x0807e4c8 in do_catch_errors (uiout=0x82c99a0, data=0xbfffe708) at top.c:524 #26 0x0807e26c in catcher (func=0x807e4ac <do_catch_errors>, func_uiout=0x82c99a0, func_args=0xbfffe708, func_val=0xbfffe714, func_caught=0xbfffe710, errstring=0x823bd9a "", gdberrmsg=0x0, mask=0x6) at top.c:431 #27 0x0807e51c in catch_errors (func=0x8074977 <captured_main>, func_args=0xbfffe750, errstring=0x823bd9a "", mask=0x6) at top.c:536 #28 0x0807584f in gdb_main (args=0xbfffe750) at main.c:810 #29 0x08074934 in main (argc=0x1, argv=0xbfffe7f4) at gdb.c:35 gdb> x/x $eip 0x80b60fc <lookup_cmd_1+665>: 0x4489008b gdb> x/10i $eip 0x80b60fc <lookup_cmd_1+665>: mov (%eax),%eax 0x80b60fe <lookup_cmd_1+667>: mov %eax,0x4(%esp) 0x80b6102 <lookup_cmd_1+671>: mov 0x8(%ebp),%eax 0x80b6105 <lookup_cmd_1+674>: mov %eax,(%esp) 0x80b6108 <lookup_cmd_1+677>: call 0x80b5e63 <lookup_cmd_1> 0x80b610d <lookup_cmd_1+682>: mov %eax,0xffffffe4(%ebp) 0x80b6110 <lookup_cmd_1+685>: cmpl $0x0,0xffffffe4(%ebp) 0x80b6114 <lookup_cmd_1+689>: jne 0x80b612c <lookup_cmd_1+713> 0x80b6116 <lookup_cmd_1+691>: cmpl $0x0,0x10(%ebp) 0x80b611a <lookup_cmd_1+695>: je 0x80b6124 <lookup_cmd_1+705> gdb> i r eax eax 0x21 0x21 gdb> i r eax 0x21 0x21 ecx 0xbfffde95 0xbfffde95 edx 0x82e67b6 0x82e67b6 ebx 0xb7fd37d4 0xb7fd37d4 esp 0xbfffde80 0xbfffde80 ebp 0xbfffded8 0xbfffded8 esi 0x831e0c8 0x831e0c8 edi 0xb7fd8018 0xb7fd8018 eip 0x80b60fc 0x80b60fc eflags 0x210206 0x210206 cs 0x73 0x73 ss 0x7b 0x7b ds 0x7b 0x7b es 0x7b 0x7b fs 0x0 0x0 gs 0x33 0x33 gdb> disas Dump of assembler code for function lookup_cmd_1: 0x080b5e63 <lookup_cmd_1+0>: push %ebp 0x080b5e64 <lookup_cmd_1+1>: mov %esp,%ebp 0x080b5e66 <lookup_cmd_1+3>: sub $0x48,%esp 0x080b5e69 <lookup_cmd_1+6>: mov 0x8(%ebp),%eax 0x080b5e6c <lookup_cmd_1+9>: mov (%eax),%eax 0x080b5e6e <lookup_cmd_1+11>: mov %eax,0xffffffe0(%ebp) 0x080b5e71 <lookup_cmd_1+14>: mov 0x8(%ebp),%eax 0x080b5e74 <lookup_cmd_1+17>: mov (%eax),%eax 0x080b5e76 <lookup_cmd_1+19>: cmpb $0x20,(%eax) 0x080b5e79 <lookup_cmd_1+22>: je 0x80b5e87 <lookup_cmd_1+36> 0x080b5e7b <lookup_cmd_1+24>: mov 0x8(%ebp),%eax 0x080b5e7e <lookup_cmd_1+27>: mov (%eax),%eax 0x080b5e80 <lookup_cmd_1+29>: cmpb $0x9,(%eax) 0x080b5e83 <lookup_cmd_1+32>: je 0x80b5e87 <lookup_cmd_1+36> 0x080b5e85 <lookup_cmd_1+34>: jmp 0x80b5e8e <lookup_cmd_1+43> 0x080b5e87 <lookup_cmd_1+36>: mov 0x8(%ebp),%eax 0x080b5e8a <lookup_cmd_1+39>: incl (%eax) 0x080b5e8c <lookup_cmd_1+41>: jmp 0x80b5e71 <lookup_cmd_1+14> 0x080b5e8e <lookup_cmd_1+43>: mov 0x8(%ebp),%eax 0x080b5e91 <lookup_cmd_1+46>: mov (%eax),%eax 0x080b5e93 <lookup_cmd_1+48>: mov %eax,0xfffffffc(%ebp) 0x080b5e96 <lookup_cmd_1+51>: mov 0xfffffffc(%ebp),%eax 0x080b5e99 <lookup_cmd_1+54>: cmpb $0x0,(%eax) 0x080b5e9c <lookup_cmd_1+57>: je 0x80b5f25 <lookup_cmd_1+194> 0x080b5ea2 <lookup_cmd_1+63>: call 0x8074720 <free+592> 0x080b5ea7 <lookup_cmd_1+68>: mov %eax,%ecx 0x080b5ea9 <lookup_cmd_1+70>: mov 0xfffffffc(%ebp),%eax 0x080b5eac <lookup_cmd_1+73>: movsbl (%eax),%eax 0x080b5eaf <lookup_cmd_1+76>: lea (%eax,%eax,1),%edx 0x080b5eb2 <lookup_cmd_1+79>: mov (%ecx),%eax 0x080b5eb4 <lookup_cmd_1+81>: movzwl (%eax,%edx,1),%eax 0x080b5eb8 <lookup_cmd_1+85>: and $0x8,%eax 0x080b5ebb <lookup_cmd_1+88>: test %eax,%eax 0x080b5ebd <lookup_cmd_1+90>: jne 0x80b5f1b <lookup_cmd_1+184> 0x080b5ebf <lookup_cmd_1+92>: mov 0xfffffffc(%ebp),%eax 0x080b5ec2 <lookup_cmd_1+95>: cmpb $0x2d,(%eax) 0x080b5ec5 <lookup_cmd_1+98>: je 0x80b5f1b <lookup_cmd_1+184> 0x080b5ec7 <lookup_cmd_1+100>: mov 0xfffffffc(%ebp),%eax 0x080b5eca <lookup_cmd_1+103>: cmpb $0x5f,(%eax) 0x080b5ecd <lookup_cmd_1+106>: je 0x80b5f1b <lookup_cmd_1+184> 0x080b5ecf <lookup_cmd_1+108>: cmpl $0x0,0x82cfdd8 0x080b5ed6 <lookup_cmd_1+115>: je 0x80b5ef8 <lookup_cmd_1+149> 0x080b5ed8 <lookup_cmd_1+117>: mov 0xfffffffc(%ebp),%eax 0x080b5edb <lookup_cmd_1+120>: cmpb $0x2b,(%eax) 0x080b5ede <lookup_cmd_1+123>: je 0x80b5f1b <lookup_cmd_1+184> 0x080b5ee0 <lookup_cmd_1+125>: mov 0xfffffffc(%ebp),%eax 0x080b5ee3 <lookup_cmd_1+128>: cmpb $0x3c,(%eax) 0x080b5ee6 <lookup_cmd_1+131>: je 0x80b5f1b <lookup_cmd_1+184> 0x080b5ee8 <lookup_cmd_1+133>: mov 0xfffffffc(%ebp),%eax 0x080b5eeb <lookup_cmd_1+136>: cmpb $0x3e,(%eax) 0x080b5eee <lookup_cmd_1+139>: je 0x80b5f1b <lookup_cmd_1+184> 0x080b5ef0 <lookup_cmd_1+141>: mov 0xfffffffc(%ebp),%eax 0x080b5ef3 <lookup_cmd_1+144>: cmpb $0x24,(%eax) 0x080b5ef6 <lookup_cmd_1+147>: je 0x80b5f1b <lookup_cmd_1+184> 0x080b5ef8 <lookup_cmd_1+149>: cmpl $0x0,0x82cc644 0x080b5eff <lookup_cmd_1+156>: je 0x80b5f25 <lookup_cmd_1+194> 0x080b5f01 <lookup_cmd_1+158>: mov 0xfffffffc(%ebp),%eax 0x080b5f04 <lookup_cmd_1+161>: cmpb $0x21,(%eax) 0x080b5f07 <lookup_cmd_1+164>: je 0x80b5f1b <lookup_cmd_1+184> 0x080b5f09 <lookup_cmd_1+166>: mov 0xfffffffc(%ebp),%eax 0x080b5f0c <lookup_cmd_1+169>: cmpb $0x2f,(%eax) 0x080b5f0f <lookup_cmd_1+172>: je 0x80b5f1b <lookup_cmd_1+184> 0x080b5f11 <lookup_cmd_1+174>: mov 0xfffffffc(%ebp),%eax 0x080b5f14 <lookup_cmd_1+177>: cmpb $0x3f,(%eax) 0x080b5f17 <lookup_cmd_1+180>: je 0x80b5f1b <lookup_cmd_1+184> 0x080b5f19 <lookup_cmd_1+182>: jmp 0x80b5f25 <lookup_cmd_1+194> 0x080b5f1b <lookup_cmd_1+184>: lea 0xfffffffc(%ebp),%eax 0x080b5f1e <lookup_cmd_1+187>: incl (%eax) 0x080b5f20 <lookup_cmd_1+189>: jmp 0x80b5e96 <lookup_cmd_1+51> 0x080b5f25 <lookup_cmd_1+194>: mov 0x8(%ebp),%edx 0x080b5f28 <lookup_cmd_1+197>: mov 0xfffffffc(%ebp),%eax 0x080b5f2b <lookup_cmd_1+200>: cmp (%edx),%eax 0x080b5f2d <lookup_cmd_1+202>: jne 0x80b5f3b <lookup_cmd_1+216> 0x080b5f2f <lookup_cmd_1+204>: movl $0x0,0xffffffd8(%ebp) 0x080b5f36 <lookup_cmd_1+211>: jmp 0x80b616c <lookup_cmd_1+777> 0x080b5f3b <lookup_cmd_1+216>: mov 0x8(%ebp),%eax 0x080b5f3e <lookup_cmd_1+219>: mov (%eax),%edx 0x080b5f40 <lookup_cmd_1+221>: mov 0xfffffffc(%ebp),%eax 0x080b5f43 <lookup_cmd_1+224>: sub %edx,%eax 0x080b5f45 <lookup_cmd_1+226>: mov %eax,0xfffffff4(%ebp) 0x080b5f48 <lookup_cmd_1+229>: mov 0xfffffff4(%ebp),%eax 0x080b5f4b <lookup_cmd_1+232>: inc %eax 0x080b5f4c <lookup_cmd_1+233>: add $0xf,%eax 0x080b5f4f <lookup_cmd_1+236>: shr $0x4,%eax 0x080b5f52 <lookup_cmd_1+239>: shl $0x4,%eax 0x080b5f55 <lookup_cmd_1+242>: sub %eax,%esp 0x080b5f57 <lookup_cmd_1+244>: lea 0x14(%esp),%eax 0x080b5f5b <lookup_cmd_1+248>: mov %eax,0xfffffff8(%ebp) 0x080b5f5e <lookup_cmd_1+251>: movl $0x0,0xfffffff0(%ebp) 0x080b5f65 <lookup_cmd_1+258>: mov 0xfffffff0(%ebp),%eax 0x080b5f68 <lookup_cmd_1+261>: cmp 0xfffffff4(%ebp),%eax 0x080b5f6b <lookup_cmd_1+264>: jl 0x80b5f6f <lookup_cmd_1+268> 0x080b5f6d <lookup_cmd_1+266>: jmp 0x80b5f92 <lookup_cmd_1+303> 0x080b5f6f <lookup_cmd_1+268>: mov 0x8(%ebp),%edx 0x080b5f72 <lookup_cmd_1+271>: mov 0xfffffff0(%ebp),%eax 0x080b5f75 <lookup_cmd_1+274>: add (%edx),%eax 0x080b5f77 <lookup_cmd_1+276>: movzbl (%eax),%eax 0x080b5f7a <lookup_cmd_1+279>: mov %al,0xffffffdf(%ebp) 0x080b5f7d <lookup_cmd_1+282>: mov 0xfffffff0(%ebp),%eax 0x080b5f80 <lookup_cmd_1+285>: mov 0xfffffff8(%ebp),%edx 0x080b5f83 <lookup_cmd_1+288>: add %eax,%edx 0x080b5f85 <lookup_cmd_1+290>: movzbl 0xffffffdf(%ebp),%eax 0x080b5f89 <lookup_cmd_1+294>: mov %al,(%edx) 0x080b5f8b <lookup_cmd_1+296>: lea 0xfffffff0(%ebp),%eax 0x080b5f8e <lookup_cmd_1+299>: incl (%eax) 0x080b5f90 <lookup_cmd_1+301>: jmp 0x80b5f65 <lookup_cmd_1+258> 0x080b5f92 <lookup_cmd_1+303>: mov 0xfffffff4(%ebp),%eax 0x080b5f95 <lookup_cmd_1+306>: add 0xfffffff8(%ebp),%eax 0x080b5f98 <lookup_cmd_1+309>: movb $0x0,(%eax) 0x080b5f9b <lookup_cmd_1+312>: movl $0x0,0xffffffe8(%ebp) 0x080b5fa2 <lookup_cmd_1+319>: movl $0x0,0xffffffec(%ebp) 0x080b5fa9 <lookup_cmd_1+326>: lea 0xffffffec(%ebp),%eax 0x080b5fac <lookup_cmd_1+329>: mov %eax,0x10(%esp) 0x080b5fb0 <lookup_cmd_1+333>: mov 0x14(%ebp),%eax 0x080b5fb3 <lookup_cmd_1+336>: mov %eax,0xc(%esp) 0x080b5fb7 <lookup_cmd_1+340>: mov 0xc(%ebp),%eax 0x080b5fba <lookup_cmd_1+343>: mov %eax,0x8(%esp) 0x080b5fbe <lookup_cmd_1+347>: mov 0xfffffff4(%ebp),%eax 0x080b5fc1 <lookup_cmd_1+350>: mov %eax,0x4(%esp) 0x080b5fc5 <lookup_cmd_1+354>: mov 0xfffffff8(%ebp),%eax 0x080b5fc8 <lookup_cmd_1+357>: mov %eax,(%esp) 0x080b5fcb <lookup_cmd_1+360>: call 0x80b5ddb <find_cmd> 0x080b5fd0 <lookup_cmd_1+365>: mov %eax,0xffffffe8(%ebp) 0x080b5fd3 <lookup_cmd_1+368>: cmpl $0x0,0xffffffe8(%ebp) 0x080b5fd7 <lookup_cmd_1+372>: je 0x80b5fe3 <lookup_cmd_1+384> 0x080b5fd9 <lookup_cmd_1+374>: cmpl $0x0,0xffffffec(%ebp) 0x080b5fdd <lookup_cmd_1+378>: jne 0x80b607a <lookup_cmd_1+535> 0x080b5fe3 <lookup_cmd_1+384>: movl $0x0,0xfffffff0(%ebp) 0x080b5fea <lookup_cmd_1+391>: mov 0xfffffff0(%ebp),%eax 0x080b5fed <lookup_cmd_1+394>: cmp 0xfffffff4(%ebp),%eax 0x080b5ff0 <lookup_cmd_1+397>: jl 0x80b5ff4 <lookup_cmd_1+401> 0x080b5ff2 <lookup_cmd_1+399>: jmp 0x80b6050 <lookup_cmd_1+493> 0x080b5ff4 <lookup_cmd_1+401>: mov 0xfffffff0(%ebp),%eax 0x080b5ff7 <lookup_cmd_1+404>: add 0xfffffff8(%ebp),%eax 0x080b5ffa <lookup_cmd_1+407>: movzbl (%eax),%eax 0x080b5ffd <lookup_cmd_1+410>: mov %al,0xffffffdf(%ebp) 0x080b6000 <lookup_cmd_1+413>: mov 0xfffffff0(%ebp),%eax 0x080b6003 <lookup_cmd_1+416>: mov 0xfffffff8(%ebp),%edx 0x080b6006 <lookup_cmd_1+419>: add %eax,%edx 0x080b6008 <lookup_cmd_1+421>: mov %edx,0xffffffd4(%ebp) 0x080b600b <lookup_cmd_1+424>: call 0x8074720 <free+592> 0x080b6010 <lookup_cmd_1+429>: mov %eax,%ecx 0x080b6012 <lookup_cmd_1+431>: movsbl 0xffffffdf(%ebp),%eax 0x080b6016 <lookup_cmd_1+435>: lea (%eax,%eax,1),%edx 0x080b6019 <lookup_cmd_1+438>: mov (%ecx),%eax 0x080b601b <lookup_cmd_1+440>: movzwl (%eax,%edx,1),%eax 0x080b601f <lookup_cmd_1+444>: and $0x100,%eax 0x080b6024 <lookup_cmd_1+449>: test %eax,%eax 0x080b6026 <lookup_cmd_1+451>: je 0x80b6039 <lookup_cmd_1+470> 0x080b6028 <lookup_cmd_1+453>: movsbl 0xffffffdf(%ebp),%eax 0x080b602c <lookup_cmd_1+457>: mov %eax,(%esp) 0x080b602f <lookup_cmd_1+460>: call 0x8073cd0 <_init+1256> 0x080b6034 <lookup_cmd_1+465>: mov %al,0xffffffd3(%ebp) 0x080b6037 <lookup_cmd_1+468>: jmp 0x80b6040 <lookup_cmd_1+477> 0x080b6039 <lookup_cmd_1+470>: movzbl 0xffffffdf(%ebp),%eax 0x080b603d <lookup_cmd_1+474>: mov %al,0xffffffd3(%ebp) 0x080b6040 <lookup_cmd_1+477>: movzbl 0xffffffd3(%ebp),%edx 0x080b6044 <lookup_cmd_1+481>: mov 0xffffffd4(%ebp),%eax 0x080b6047 <lookup_cmd_1+484>: mov %dl,(%eax) 0x080b6049 <lookup_cmd_1+486>: lea 0xfffffff0(%ebp),%eax 0x080b604c <lookup_cmd_1+489>: incl (%eax) 0x080b604e <lookup_cmd_1+491>: jmp 0x80b5fea <lookup_cmd_1+391> 0x080b6050 <lookup_cmd_1+493>: lea 0xffffffec(%ebp),%eax 0x080b6053 <lookup_cmd_1+496>: mov %eax,0x10(%esp) 0x080b6057 <lookup_cmd_1+500>: mov 0x14(%ebp),%eax 0x080b605a <lookup_cmd_1+503>: mov %eax,0xc(%esp) 0x080b605e <lookup_cmd_1+507>: mov 0xc(%ebp),%eax 0x080b6061 <lookup_cmd_1+510>: mov %eax,0x8(%esp) 0x080b6065 <lookup_cmd_1+514>: mov 0xfffffff4(%ebp),%eax 0x080b6068 <lookup_cmd_1+517>: mov %eax,0x4(%esp) 0x080b606c <lookup_cmd_1+521>: mov 0xfffffff8(%ebp),%eax 0x080b606f <lookup_cmd_1+524>: mov %eax,(%esp) 0x080b6072 <lookup_cmd_1+527>: call 0x80b5ddb <find_cmd> 0x080b6077 <lookup_cmd_1+532>: mov %eax,0xffffffe8(%ebp) 0x080b607a <lookup_cmd_1+535>: cmpl $0x0,0xffffffec(%ebp) 0x080b607e <lookup_cmd_1+539>: jne 0x80b608c <lookup_cmd_1+553> 0x080b6080 <lookup_cmd_1+541>: movl $0x0,0xffffffd8(%ebp) 0x080b6087 <lookup_cmd_1+548>: jmp 0x80b616c <lookup_cmd_1+777> 0x080b608c <lookup_cmd_1+553>: cmpl $0x1,0xffffffec(%ebp) 0x080b6090 <lookup_cmd_1+557>: jle 0x80b60ad <lookup_cmd_1+586> 0x080b6092 <lookup_cmd_1+559>: cmpl $0x0,0x10(%ebp) 0x080b6096 <lookup_cmd_1+563>: je 0x80b60a1 <lookup_cmd_1+574> 0x080b6098 <lookup_cmd_1+565>: mov 0x10(%ebp),%eax 0x080b609b <lookup_cmd_1+568>: movl $0x0,(%eax) 0x080b60a1 <lookup_cmd_1+574>: movl $0xffffffff,0xffffffd8(%ebp) 0x080b60a8 <lookup_cmd_1+581>: jmp 0x80b616c <lookup_cmd_1+777> 0x080b60ad <lookup_cmd_1+586>: mov 0x8(%ebp),%eax 0x080b60b0 <lookup_cmd_1+589>: mov 0xfffffffc(%ebp),%edx 0x080b60b3 <lookup_cmd_1+592>: mov %edx,(%eax) 0x080b60b5 <lookup_cmd_1+594>: mov 0xffffffe8(%ebp),%eax 0x080b60b8 <lookup_cmd_1+597>: cmpl $0x0,0x60(%eax) 0x080b60bc <lookup_cmd_1+601>: je 0x80b60df <lookup_cmd_1+636> 0x080b60be <lookup_cmd_1+603>: mov 0xffffffe8(%ebp),%eax 0x080b60c1 <lookup_cmd_1+606>: mov 0x1c(%eax),%eax 0x080b60c4 <lookup_cmd_1+609>: and $0x2,%eax 0x080b60c7 <lookup_cmd_1+612>: test %eax,%eax 0x080b60c9 <lookup_cmd_1+614>: je 0x80b60d6 <lookup_cmd_1+627> 0x080b60cb <lookup_cmd_1+616>: lea 0xffffffe0(%ebp),%eax 0x080b60ce <lookup_cmd_1+619>: mov %eax,(%esp) 0x080b60d1 <lookup_cmd_1+622>: call 0x80b6516 <deprecated_cmd_warning> 0x080b60d6 <lookup_cmd_1+627>: mov 0xffffffe8(%ebp),%eax 0x080b60d9 <lookup_cmd_1+630>: mov 0x60(%eax),%eax 0x080b60dc <lookup_cmd_1+633>: mov %eax,0xffffffe8(%ebp) 0x080b60df <lookup_cmd_1+636>: mov 0xffffffe8(%ebp),%eax 0x080b60e2 <lookup_cmd_1+639>: cmpl $0x0,0x34(%eax) 0x080b60e6 <lookup_cmd_1+643>: je 0x80b6158 <lookup_cmd_1+757> 0x080b60e8 <lookup_cmd_1+645>: mov 0x14(%ebp),%eax 0x080b60eb <lookup_cmd_1+648>: mov %eax,0xc(%esp) 0x080b60ef <lookup_cmd_1+652>: mov 0x10(%ebp),%eax 0x080b60f2 <lookup_cmd_1+655>: mov %eax,0x8(%esp) 0x080b60f6 <lookup_cmd_1+659>: mov 0xffffffe8(%ebp),%eax 0x080b60f9 <lookup_cmd_1+662>: mov 0x34(%eax),%eax 0x080b60fc <lookup_cmd_1+665>: mov (%eax),%eax 0x080b60fe <lookup_cmd_1+667>: mov %eax,0x4(%esp) 0x080b6102 <lookup_cmd_1+671>: mov 0x8(%ebp),%eax 0x080b6105 <lookup_cmd_1+674>: mov %eax,(%esp) 0x080b6108 <lookup_cmd_1+677>: call 0x80b5e63 <lookup_cmd_1> 0x080b610d <lookup_cmd_1+682>: mov %eax,0xffffffe4(%ebp) 0x080b6110 <lookup_cmd_1+685>: cmpl $0x0,0xffffffe4(%ebp) 0x080b6114 <lookup_cmd_1+689>: jne 0x80b612c <lookup_cmd_1+713> 0x080b6116 <lookup_cmd_1+691>: cmpl $0x0,0x10(%ebp) 0x080b611a <lookup_cmd_1+695>: je 0x80b6124 <lookup_cmd_1+705> 0x080b611c <lookup_cmd_1+697>: mov 0x10(%ebp),%edx 0x080b611f <lookup_cmd_1+700>: mov 0xc(%ebp),%eax 0x080b6122 <lookup_cmd_1+703>: mov %eax,(%edx) 0x080b6124 <lookup_cmd_1+705>: mov 0xffffffe8(%ebp),%eax 0x080b6127 <lookup_cmd_1+708>: mov %eax,0xffffffd8(%ebp) 0x080b612a <lookup_cmd_1+711>: jmp 0x80b616c <lookup_cmd_1+777> 0x080b612c <lookup_cmd_1+713>: cmpl $0xffffffff,0xffffffe4(%ebp) 0x080b6130 <lookup_cmd_1+717>: jne 0x80b6150 <lookup_cmd_1+749> 0x080b6132 <lookup_cmd_1+719>: cmpl $0x0,0x10(%ebp) 0x080b6136 <lookup_cmd_1+723>: je 0x80b6148 <lookup_cmd_1+741> 0x080b6138 <lookup_cmd_1+725>: mov 0x10(%ebp),%eax 0x080b613b <lookup_cmd_1+728>: cmpl $0x0,(%eax) 0x080b613e <lookup_cmd_1+731>: jne 0x80b6148 <lookup_cmd_1+741> 0x080b6140 <lookup_cmd_1+733>: mov 0x10(%ebp),%edx 0x080b6143 <lookup_cmd_1+736>: mov 0xffffffe8(%ebp),%eax 0x080b6146 <lookup_cmd_1+739>: mov %eax,(%edx) 0x080b6148 <lookup_cmd_1+741>: mov 0xffffffe4(%ebp),%eax 0x080b614b <lookup_cmd_1+744>: mov %eax,0xffffffd8(%ebp) 0x080b614e <lookup_cmd_1+747>: jmp 0x80b616c <lookup_cmd_1+777> 0x080b6150 <lookup_cmd_1+749>: mov 0xffffffe4(%ebp),%eax 0x080b6153 <lookup_cmd_1+752>: mov %eax,0xffffffd8(%ebp) 0x080b6156 <lookup_cmd_1+755>: jmp 0x80b616c <lookup_cmd_1+777> 0x080b6158 <lookup_cmd_1+757>: cmpl $0x0,0x10(%ebp) 0x080b615c <lookup_cmd_1+761>: je 0x80b6166 <lookup_cmd_1+771> 0x080b615e <lookup_cmd_1+763>: mov 0x10(%ebp),%edx 0x080b6161 <lookup_cmd_1+766>: mov 0xc(%ebp),%eax 0x080b6164 <lookup_cmd_1+769>: mov %eax,(%edx) 0x080b6166 <lookup_cmd_1+771>: mov 0xffffffe8(%ebp),%eax 0x080b6169 <lookup_cmd_1+774>: mov %eax,0xffffffd8(%ebp) 0x080b616c <lookup_cmd_1+777>: mov 0xffffffd8(%ebp),%eax 0x080b616f <lookup_cmd_1+780>: leave 0x080b6170 <lookup_cmd_1+781>: ret End of assembler dump. gdb> Heh never thought I'll debug core produced by gdb with itself :) Additions system information: $ emerge info Portage 2.0.51.19 (default-linux/x86/2005.0, gcc-3.3.5-20050130-vanilla, glibc-2.3.4.20041102-r1, 2.6.11-gentoo-r11 i686) ================================================================= System uname: 2.6.11-gentoo-r11 i686 Intel(R) Pentium(R) 4 CPU 2.80GHz Gentoo Base System version 1.6.12 Python: dev-lang/python-2.3.5 [2.3.5 (#1, May 6 2005, 12:55:31)] dev-lang/python: 2.3.5 sys-apps/sandbox: 1.2.9 sys-devel/autoconf: 2.59-r6, 2.13 sys-devel/automake: 1.8.5-r3, 1.5, 1.4_p6, 1.6.3, 1.7.9, 1.9.5 sys-devel/binutils: 2.15.92.0.2-r10, 2.15.92.0.2-r1, 2.16-r1 sys-devel/libtool: 1.5.16 virtual/os-headers: 2.6.11-r1 ACCEPT_KEYWORDS="x86" AUTOCLEAN="yes" CFLAGS="-march=prescott -O2 -pipe" CHOST="i686-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/kde/2/share/config /usr/kde/3.4/env /usr/kde/3.4/share/config /usr/kde/3.4/shutdown /usr/kde/3/share/config /usr/lib/X11/xkb /usr/share/config /usr/share/texmf/dvipdfm/config/ /usr/share/texmf/dvips/config/ /usr/share/texmf/tex/generic/config/ /usr/share/texmf/tex/platex/config/ /usr/share/texmf/xdvi/ /var/bind /var/qmail/control /var/service" CONFIG_PROTECT_MASK="/etc/gconf /etc/terminfo /etc/env.d" CXXFLAGS="-march=prescott -O2 -pipe" DISTDIR="/usr/portage/distfiles" FEATURES="autoaddcvs autoconfig ccache distlocks sandbox sfperms strict" GENTOO_MIRRORS="http://mirror.datapipe.net/gentoo ftp://ftp.du.se/pub/os/gentoo http://trumpetti.atm.tut.fi/gentoo/ ftp://mirrors1.netvisao.pt/gentoo/ http://www.gigaload.org/gentoo.org/" LANG="ru_RU.cp1251" LINGUAS="en ru" MAKEOPTS="-j2" PKGDIR="/usr/portage/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/usr/local/overlays/my /usr/local/overlays/bmg-main" SYNC="rsync://rsync.gentoo.org/gentoo-portage" USE="x86 X aalib acl activefilter alsa apache2 apm arts artswrappersuid audiofile avi bash-completion berkdb bitmap-fonts caps cdparanoia cdr crypt cups curl dba dhcp directfb divx4linux divxforlinux doc dvd dvdr dvdread eds emboss encode erandom esd fam fbcon flac font-server foomaticdb fortran gd gd-external gdbm gif gnokii gnome gphoto2 gpm gstreamer gtk gtk2 guile hal hardened imagemagick imlib innodb ipv6 jack java jpeg junit kde kerberos ldap libclamav libg++ libwww lirc lm_sensors logrotate mad mbox mikmod milter mime mmap mmx mmxext motif mp3 mpeg mppe-mppc multislot mysql ncurses nls nptl ntlm ogg oggvorbis opengl oss pam pda pdflib perl pic png portaudio povray procmail python qt quicktime quotas rdesktop readline real recode reiserfs ruby samba sasl scanner sdl sftplogging slang slp snmp socks5 speex spell sse sse2 ssl svga tcltk tcpd tetex theora threads tiff truetype truetype-fonts type1-fonts usb v4l v4l2 vorbis wifi win32codecs winbind wmf xine xinerama xml xml2 xmms xscreensaver xv xvid zlib linguas_en linguas_ru userland_GNU kernel_linux elibc_glibc" Unset: ASFLAGS, CBUILD, CTARGET, LC_ALL, LDFLAGS
The segfault is due found->prefixlist pointer dereference because found->prefixlist==0x21 is invalid address. gdb> list 1077 1072 } 1073 /* If we found a prefix command, keep looking. */ 1074 1075 if (found->prefixlist) 1076 { 1077 c = lookup_cmd_1 (text, *found->prefixlist, result_list, 1078 ignore_help_classes); 1079 if (!c) 1080 { 1081 /* Didn't find anything; this is as far as we got. */ gdb> x/x found 0x8305bc8: 0x00736964 gdb> x/x *found Value can't be converted to integer. gdb> x/x found 0x8305bc8: 0x00736964 gdb> print found $1 = (struct cmd_list_element *) 0x8305bc8 gdb> print *found $2 = {next = 0x736964, name = 0x80d565f "U\211еЗ\005\020\005-\b", class = class_deprecated, func = 0x19, function = {cfunc = 0, sfunc = 0}, context = 0x8302c28, doc = 0x0, flags = 0x0, replacement = 0x0, pre_show_hook = 0x11, hook_pre = 0x69637361, hook_post = 0x68635f69, hook_in = 0x7261, prefixlist = 0x21, prefixname = 0x6e697250 <Address 0x6e697250 out of bounds>, allow_unknown = 0x74, abbrev_flag = 0x20, completer = 0x64616572, type = 1852383347, var = 0x72617420, var_type = 7628135, enums = 0x0, user_commands = 0x11, hookee_pre = 0x47320075, hookee_post = 0x4732c7e8, cmd_pointer = 0x10} gdb>
can youcheck that gdb-6.3-r4 fails if you build it with USE=vanilla ? USE=vanilla will prevent all patches from being applied and basically just give you the same thing as if you unpacked the original tarball and built/installed it yourself ...
After reemerging gdb with CFLAGS="-pipe -ggdb3" USE="debug vanilla" FEATURES=nostrip emerge gdb it continues to segfault at the same place in lookup_cmd_1() each time "help t" command given if there is standard .gdbinit file in the home directory. It seems there is an overflow somewhere that's why "found" structure has been overwriten: gdb> x/50c found 0x83256d8: 0 '\0' 0 '\0' 0 '\0' 0 '\0' 16 '\020' 87 'W' 50 '2' 8 '\b' 0x83256e0: 0 '\0' 0 '\0' 0 '\0' 0 '\0' 0 '\0' 0 '\0' 0 '\0' 0 '\0' 0x83256e8: 0 '\0' 0 '\0' 0 '\0' 0 '\0' 33 '!' 0 '\0' 0 '\0' 0 '\0' 0x83256f0: 80 'P' 114 'r' 105 'i' 110 'n' 116 't' 32 ' ' 116 't' 104 'h' 0x83256f8: 114 'r' 101 'e' 97 'a' 100 'd' 115 's' 32 ' ' 105 'i' 110 'n' 0x8325700: 32 ' ' 116 't' 97 'a' 114 'r' 103 'g' 101 'e' 116 't' 0 '\0' 0x8325708: 0 '\0' 0 '\0'
ok, well i hate to do this to you since you've put a lot of work into this, but we just dont have anyone in Gentoo with real gdb knowledge ... that means i'm gonna have to ask you to file a bug upstream: http://sources.redhat.com/cgi-bin/gnatsweb.pl sorry :/
ok, not a problem
