0000496: Tcsh hangs in pprint - MantisBT

ID	Project	Category	View Status	Date Submitted	Last Update

0000496	tcsh	General	public	2023-12-14 02:34	2023-12-14 02:34

Reporter	spokh	Assigned To
Priority	normal	Severity	crash	Reproducibility	sometimes
Status	new	Resolution	open
OS	CentOS	OS Version	7.3
Product Version	6.24.10

Summary	0000496: Tcsh hangs in pprint
Description	I had two jobs running in background. I ran "%2" command to bring second one to foreground. I got following error: 2: No such job (badjob). After that, tcsh hangs, and does not give me any prompt. I had seen this issue earlier with previous tcsh versions, but it would happen only once in a while. Anyways, I wanted to really get issue fixed, so I had installed debug version of latest tcsh. I have attached gdb to tcsh, and it shows following stack-trace: #0 pprint (pp=0x6f3560, flag=7) at sh.proc.c:997 0000001 0x00000000004244f5 in pnote () at sh.proc.c:435 0000002 0x000000000040692d in process (catch=1) at sh.c:2037 0000003 0x000000000040572e in main (argc=0, argv=0x7fffffffca08) at sh.c:1432 I tried to debug it, and I could see that it is stuck in following loop: 997 while (pp->p_procid != pp->p_jobid) 998 pp = pp->p_friends; (gdb) p pp $13 = (struct process ) 0x6f3560 (gdb) p pp->p_procid $14 = 0 (gdb) p pp->p_friends $15 = (struct process ) 0x6f3560 As you can see, "pp->p_friends" is same as "pp", so the list is circular list, and iteration would never end. I would keep my gdb attached to tcsh, so if you have any suggestion to check in gdb, please let me know.
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Date Modified	Username	Field	Change
2023-12-14 02:34	spokh	New Issue