Thanks Dave. I found one more issue with a somewhat "corrupt" vmcore. In this case it is ARM-specific in unwind_arm.c, so maybe Mika will also look at it. In the case I am investigating I get a readmem error while reading the unwind tables. The way unwinding currently is implemented Crash then stops and no further analysis is possible. When I patched Crash to continue anyhow, every command I tried worked nicely including bt, so there is no reason to stop at this kind of problem. When investigating further I found that the problem occurs in init_module_unwind_tables. It is in the call to do_list(&ld) that the readmem error is found. I also looked in the code for do_list and saw that it could be configured to return even if errors were found, by setting ld.flags. /* * Iterate through unwind table list and store start address of each * table in table_list. */ ld.flags += RETURN_ON_LIST_ERROR; /* added line */ hq_open(); cnt = do_list(&ld); if (cnt == -1) { /* added if statement, 3 lines */ return FALSE; } table_list = (ulong *)GETBUF(cnt * sizeof(ulong)); cnt = retrieve_list(table_list, cnt); hq_close(); By adding the lines indicated above I get an appropriate warning that the unwind tables cannot be read, and then Crash works as usual. Jan Jan Karlsson Senior Software Engineer MIB Sony Mobile Communications Tel: +46703062174 sonymobile.com -----Original Message----- From: crash-utility-bounces@xxxxxxxxxx [mailto:crash-utility-bounces@xxxxxxxxxx] On Behalf Of Dave Anderson Sent: torsdag den 26 april 2012 15:09 To: Discussion list for crash utility usage, maintenance and development Cc: Fänge, Thomas Subject: Re: loop in crash ----- Original Message ----- > Hi > > and thanks for your work with this problem. > > As you expected crash silently just loops and I spotted the problem > by turning on debug printouts. > If I include printouts for the "cache" address, the first value seems > reasonable, but then it starts to repeat with the value 0x00000001. > Last, your patch solves the problem nicely. I get a warning about > duplicate kmem_slab entry and crash continues to execute and issues > other warnings indicating a corrupt vmcore file. > > Jan OK good -- I should have hq_xxx()'d that loop a long time ago. Queued for crash-6.0.6. Thanks, Dave -- Crash-utility mailing list Crash-utility@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/crash-utility -- Crash-utility mailing list Crash-utility@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/crash-utility