[Bug 973450] Re: parted_server crashed with SIGSEGV in __libc_start_main()

[Peter Hurley]

Ok, here's the situation:

There is no stack backtrace because there is no debug symbol package for
parted_server (which is a binary produced from ubiquity source package
in d-i/source/partman-base/parted_server.c)

Despite that, simply loading parted_server in gdb and disassembling at the fault address was sufficient to uncover the faulting code.  In parted_server.c::command_get_file_system(), the following line will fault if fs_type == NULL:
                        if (0 == strncmp(part->fs_type->name, "linux-swap", 10))

Although this should be fixed, there is a larger problem that is
contributing to this:  the scripts feeding the parted_server are
mistaking /dev/mapper partitions as devices.

Here's the output from parted_devices on my machine: 
peter at thor:~/src/packages/ubiquity/ubiquity-2.10.8/d-i/source/partman-base$ sudo ./parted_devices
[sudo] password for peter: 
/dev/sda	1000204886016	ATA WDC WD1001FALS-0
/dev/sdb	1000204886016	ATA WDC WD1001FALS-0
/dev/sdc	250000000000	ATA ST3250310AS
/dev/sdd	160041885696	Seagate FreeAgent Go
/dev/mapper/isw_cbdbfhdjad_Raid0p6	940568928768	Linux device-mapper (linear)
/dev/mapper/isw_cbdbfhdjad_Raid0p1	1048575112704	Linux device-mapper (linear)
/dev/mapper/isw_cbdbfhdjad_Raid0p5	11260376064	Linux device-mapper (linear)
/dev/mapper/isw_cbdbfhdjad_Raid0p2	951829338112	Linux device-mapper (linear)
/dev/mapper/isw_cbdbfhdjad_Raid0	2000405397504	Linux device-mapper (striped)

Now, if you look at the partman log attached to this bug report, you'll
see that parted_server is being fed the /dev/mapper/...._Raid0p2, for
example, as a device. This is *way wrong* -- look at the crazy partition
table it came up with for this "device":

/lib/partman/init.d/35dump: IN: DUMP =dev=mapper=isw_cbdbfhdjad_Raid0p2
parted_server: Read command: DUMP
parted_server: command_dump()
parted_server: Opening outfifo
parted_server: OUT: OK


parted_server: Closing infifo and outfifo
parted_server: main_loop: iteration 20
parted_server: Opening infifo
Device: yes
Model: Linux device-mapper (linear)
Path: /dev/mapper/isw_cbdbfhdjad_Raid0p2
Sector size: 512
Sectors: 1859041676
Sectors/track: 63
Heads: 255
Cylinders: 115719
Partition table: yes
Type: msdos
Partitions: #	id	length	type	fs	path	name
(0,0,0)	(0,0,1)	-1	0-1023	1024	primary	label	/dev/mapper/isw_cbdbfhdjad_Raid0p2p-1	
(0,0,2)	(114350,253,1)	2	1024-940568929791	940568928768	primary	extended	/dev/mapper/isw_cbdbfhdjad_Raid0p2p2	
(0,0,2)	(114350,253,1)	5	1024-940568929791	940568928768	logical	ext4	/dev/mapper/isw_cbdbfhdjad_Raid0p2p5	
(114350,253,2)	(114350,254,1)	-1	940568929792-940568962047	32256	pri/log	free	/dev/mapper/isw_cbdbfhdjad_Raid0p2p-1	
(114350,254,2)	(115719,253,1)	1	940568962048-951829338111	11260376064	primary	linux-swap	/dev/mapper/isw_cbdbfhdjad_Raid0p2p1	
Dump finished.

This mishandling of fakeraid partitions should be easily reproducible on
any fakeraid machine.

FYI - the "outdated debug symbol packages" bug is a red herring. No
stack trace is possible because there are no debug symbol packages for
parted_server.

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https://bugs.launchpad.net/bugs/973450

Title:
  parted_server crashed with SIGSEGV in __libc_start_main()

Status in “ubiquity” package in Ubuntu:
  Incomplete

Bug description:
  Crash with amd64 desktop iso of 4/4/12.

  Boot from DVD, select 'Try Ubuntu', then 'Install Ubuntu 12.04'.
  Occurs after selecting 'Continue' from the 'Preparing to install
  Ubuntu'.

  Hopefully the problem with mismatched debug symbols has been fixed :)

  ProblemType: Crash
  DistroRelease: Ubuntu 12.04
  Package: ubiquity 2.10.6
  ProcVersionSignature: Ubuntu 3.2.0-21.34-generic 3.2.13
  Uname: Linux 3.2.0-21-generic x86_64
  ApportVersion: 2.0-0ubuntu4
  Architecture: amd64
  CasperVersion: 1.314
  Date: Wed Apr  4 14:42:28 2012
  ExecutablePath: /bin/parted_server
  InstallCmdLine: file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash -- maybe-ubiquity
  LiveMediaBuild: Ubuntu 12.04 LTS "Precise Pangolin" - Beta amd64 (20120404)
  ProcCmdline: parted_server
  ProcEnviron:
   TERM=unknown
   LC_COLLATE=C
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  SegvReason: reading NULL VMA
  Signal: 11
  SourcePackage: ubiquity
  StacktraceTop:
   ?? ()
   ?? ()
   ?? ()
   __libc_start_main () from /lib/x86_64-linux-gnu/libc.so.6
   ?? ()
  Title: parted_server crashed with SIGSEGV in __libc_start_main()
  UpgradeStatus: No upgrade log present (probably fresh install)
  UserGroups:

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