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Diffstat (limited to 'open_issues')
| -rw-r--r-- | open_issues/crash_server.mdwn | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/open_issues/crash_server.mdwn b/open_issues/crash_server.mdwn new file mode 100644 index 00000000..71f495cc --- /dev/null +++ b/open_issues/crash_server.mdwn @@ -0,0 +1,152 @@ +[[!meta copyright="Copyright © 2009 Free Software Foundation, Inc."]] + +[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable +id="license" text="Permission is granted to copy, distribute and/or modify this +document under the terms of the GNU Free Documentation License, Version 1.2 or +any later version published by the Free Software Foundation; with no Invariant +Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license +is included in the section entitled [[GNU Free Documentation +License|/fdl]]."]]"""]] + +[[!tag open_issue_hurd]] + +Given an `a.out` executable that only does `raise (SIGABRT)`, invoking that +one... + + * ... against `crash-dump-core` will... + + * ... not overwrite existing `core` files. + + Is this reasonable? Linux does overwrite them, for example. + + * ... show big variances in running-time behavior: + + $ TIMEFORMAT='real %R user %U system %S' + $ rm -f core; time env CRASHSERVER=/servers/crash-dump-core ./a.out; ls -l core + Aborted (core dumped) + real 1.350 user 0.000 system 0.010 + -rw------- 1 tschwinge tschwinge 17031168 Jul 7 21:59 core + $ rm -f core; time env CRASHSERVER=/servers/crash-dump-core ./a.out; ls -l core + Aborted (core dumped) + real 22.771 user 0.000 system 0.010 + -rw------- 1 tschwinge tschwinge 17031168 Jul 7 21:59 core + $ rm -f core; time env CRASHSERVER=/servers/crash-dump-core ./a.out; ls -l core + Aborted (core dumped) + real 1.367 user 0.000 system 0.010 + -rw------- 1 tschwinge tschwinge 17031168 Jul 7 22:00 core + $ rm -f core; time env CRASHSERVER=/servers/crash-dump-core ./a.out; ls -l core + Aborted (core dumped) + real 5.789 user 0.000 system 0.010 + -rw------- 1 tschwinge tschwinge 17031168 Jul 7 22:00 core + $ rm -f core; time env CRASHSERVER=/servers/crash-dump-core ./a.out; ls -l core + Aborted (core dumped) + real 22.664 user 0.010 system 0.000 + -rw------- 1 tschwinge tschwinge 17031168 Jul 7 22:01 core + + * ... produce a huge `core` file: + + $ du -hs core + 17M core + + On Linux, the `core` file occupies 76 KiB of disk space, which seems + much more reasonable. + + * ... produce an invalid `core` file: + + $ gdb a.out core + warning: core file may not match specified executable file. + [New Thread 76651] + + warning: Wrong size fpregset in core file. + Reading symbols from /lib/libc.so.0.3...[...] + Core was generated by `./a.out'. + Program terminated with signal 6, Aborted. + + warning: Wrong size fpregset in core file. + #0 0x00000000 in ?? () + (gdb) bt + #0 0x00000000 in ?? () + Cannot access memory at address 0x17 + + [[!tag open_issue_gdb]] Probably the `crash` server code and [[GDB]] are + out of sync. + + * ... against `crash-suspend` will... + + * ... not work at all: + + $ CRASHSERVER=/servers/crash-suspend ./a.out + $ [returns to the shell and doesn't suspended] + + * ... show big variances in running-time behavior: + + $ TIMEFORMAT='real %R user %U system %S' + $ rm -f core; time env CRASHSERVER=/servers/crash-suspend ./a.out; ls -l core + Aborted (core dumped) + real 1.381 user 0.000 system 0.010 + -rw------- 1 tschwinge tschwinge 17031168 Jul 7 22:04 core + $ rm -f core; time env CRASHSERVER=/servers/crash-suspend ./a.out; ls -l core + Aborted (core dumped) + real 1.332 user 0.000 system 0.010 + -rw------- 1 tschwinge tschwinge 17031168 Jul 7 22:04 core + $ rm -f core; time env CRASHSERVER=/servers/crash-suspend ./a.out; ls -l core + Aborted (core dumped) + real 21.228 user 0.000 system 0.010 + -rw------- 1 tschwinge tschwinge 17031168 Jul 7 22:04 core + $ rm -f core; time env CRASHSERVER=/servers/crash-suspend ./a.out; ls -l core + Aborted (core dumped) + real 1.323 user 0.000 system 0.010 + -rw------- 1 tschwinge tschwinge 17031168 Jul 7 22:05 core + $ rm -f core; time env CRASHSERVER=/servers/crash-suspend ./a.out; ls -l core + Aborted (core dumped) + real 22.279 user 0.000 system 0.010 + -rw------- 1 tschwinge tschwinge 17031168 Jul 7 22:05 core + $ rm -f core; time env CRASHSERVER=/servers/crash-suspend ./a.out; ls -l core + Aborted (core dumped) + real 1.362 user 0.000 system 0.000 + -rw------- 1 tschwinge tschwinge 17031168 Jul 7 22:08 core + $ rm -f core; time env CRASHSERVER=/servers/crash-suspend ./a.out; ls -l core + Aborted (core dumped) + real 21.110 user 0.000 system 0.000 + -rw------- 1 tschwinge tschwinge 17031168 Jul 7 22:08 core + $ rm -f core; time env CRASHSERVER=/servers/crash-suspend ./a.out; ls -l core + Aborted (core dumped) + real 1.350 user 0.000 system 0.020 + -rw------- 1 tschwinge tschwinge 17031168 Jul 7 22:08 core + + * ... can reliably crash GNU Mach: + + This happens if a `core` file is already present (and won't get + overwritten; see above). I reproduced this three times. + + $ TIMEFORMAT='real %R user %U system %S' + $ time env CRASHSERVER=/servers/crash-suspend ./a.out; ls -l core + Aborted + real 2.856 user 0.000 system 0.010 + -rw------- 1 tschwinge tschwinge 17031168 Jul 7 22:08 core + + panic: zalloc: zone kalloc.8192 exhausted + Kernel Breakpoint trap, eip 0x20020a77 + Stopped at 0x20020a76: int $3 + db> trace + 0x20020a76(2006aba8,4d0f7e9c,200209b0,0,0) + 0x20020a4d(2006b094,2006ae40,2000,20016803,4a5f4114) + 0x2002bca5(49a03564,1,0,9,1000) + 0x20022f4c(2000,4a5f45d4,4a84879c,49a46564,4ac43e78) + 0x20021e65(4ac43e78,4a5f45d4,4a5f4114,0,0) + 0x2005309d(2106ba9c,3,38,28,1783) + Bad frame pointer: 0x2106ba78 + + $ addr2line -i -f -e /boot/gnumach-xen 0x20020a76 0x20020a4d 0x2002bca5 0x20022f4c 0x20021e65 0x2005309d + Debugger + /home/tschwinge/tmp/gnumach/gnumach-1-branch-Xen-branch.build/../gnumach-1-branch-Xen-branch/kern/debug.c:105 + panic + /home/tschwinge/tmp/gnumach/gnumach-1-branch-Xen-branch.build/../gnumach-1-branch-Xen-branch/kern/debug.c:148 + zalloc + /home/tschwinge/tmp/gnumach/gnumach-1-branch-Xen-branch.build/../gnumach-1-branch-Xen-branch/kern/zalloc.c:470 + kalloc + /home/tschwinge/tmp/gnumach/gnumach-1-branch-Xen-branch.build/../gnumach-1-branch-Xen-branch/kern/kalloc.c:185 + ipc_kobject_server + /home/tschwinge/tmp/gnumach/gnumach-1-branch-Xen-branch.build/../gnumach-1-branch-Xen-branch/kern/ipc_kobject.c:76 + mach_msg_trap + /home/tschwinge/tmp/gnumach/gnumach-1-branch-Xen-branch.build/../gnumach-1-branch-Xen-branch/ipc/mach_msg.c:1367 |