Hi!
On 20:47 Thu 13 Oct , Richard Weinberger wrote:
> Am 13.10.2011 20:10, schrieb michi1(a)michaelblizek.twilightparadox.com:
> > After migrating from i386 to x86_64, my uml started to segfault in weird ways.
>
> What exactly is the problem?
> Without any details nobody can and will help you.
I have attached the trace below, if you are interested. It happened
during/after /sbin/init was executed. Version is
f2c0d0266cc5eb36a4aa44944b4096ec121490aa of linus'es git tree. However,
everything is running now. It was caused by uncleaned files. I am just
reporting, because this was suprising to me.
> > In the end, I figured that "make clean/mrproper/distclean" does not really
> > clean up properly. I had to use "ARCH=um make distclean". The command "make
> > distclean" did not remove these files:
> >
> > arch/um/include/shared/kern_constants.h
> > arch/um/include/shared/user_constants.h
> > arch/um/kernel/config.c
> > arch/um/kernel/config.tmp
> > arch/um/kernel/vmlinux.lds
> > arch/um/sys-x86_64/vdso/vdso.lds
> > arch/um/sys-x86_64/vdso/vdso.so
> > arch/um/sys-x86_64/vdso/vdso.so.dbg
> > arch/um/sys-x86_64/vdso/vdso-syms.lds
> >
>
> "make clean ARCH=um" works fine on my system.
Yes, the point is "ARCH=um". I do not really understand why it is needed for
clean operations?
trace:
$ gdb --args ./linux ubda=root.img
Core dump limits :
soft - 0
hard - NONE
Checking that ptrace can change system call numbers...OK
Checking syscall emulation patch for ptrace...OK
Checking advanced syscall emulation patch for ptrace...OK
Checking for tmpfs mount on /dev/shm...nothing mounted on /dev/shm
Checking PROT_EXEC mmap in /tmp/...OK
Checking for the skas3 patch in the host:
- /proc/mm...not found: No such file or directory
- PTRACE_FAULTINFO...not found
- PTRACE_LDT...not found
UML running in SKAS0 mode
Adding 22114304 bytes to physical memory to account for exec-shield gap
Initializing cgroup subsys cpu
Linux version 3.1.0-rc1-106673-g7208f79-dirty (michi@grml) (gcc version 4.4.5 (Debian 4.4.5-8) ) #1570 Thu Oct 13 18:43:52 CEST 2011
Built 1 zonelists in Zone order, mobility grouping on. Total pages: 13405
Kernel command line: ubda=root.img root=98:0
PID hash table entries: 256 (order: -1, 2048 bytes)
Dentry cache hash table entries: 8192 (order: 4, 65536 bytes)
Inode-cache hash table entries: 4096 (order: 3, 32768 bytes)
Memory: 27880k available
NR_IRQS:15
------------------------
| Locking API testsuite:
----------------------------------------------------------------------------
| spin |wlock |rlock |mutex | wsem | rsem |
--------------------------------------------------------------------------
A-A deadlock:failed|failed| ok |failed|failed|failed|
A-B-B-A deadlock:failed|failed| ok |failed|failed|failed|
A-B-B-C-C-A deadlock:failed|failed| ok |failed|failed|failed|
A-B-C-A-B-C deadlock:failed|failed| ok |failed|failed|failed|
A-B-B-C-C-D-D-A deadlock:failed|failed| ok |failed|failed|failed|
A-B-C-D-B-D-D-A deadlock:failed|failed| ok |failed|failed|failed|
A-B-C-D-B-C-D-A deadlock:failed|failed| ok |failed|failed|failed|
double unlock:failed|failed|failed| ok |failed|failed|
initialize held:failed|failed|failed|failed|failed|failed|
bad unlock order: ok | ok | ok | ok | ok | ok |
--------------------------------------------------------------------------
recursive read-lock: | ok | |failed|
recursive read-lock #2: | ok | |failed|
mixed read-write-lock: |failed| |failed|
mixed write-read-lock: |failed| |failed|
--------------------------------------------------------------------------
hard-irqs-on + irq-safe-A/12:failed|failed| ok |
soft-irqs-on + irq-safe-A/12:failed|failed| ok |
hard-irqs-on + irq-safe-A/21:failed|failed| ok |
soft-irqs-on + irq-safe-A/21:failed|failed| ok |
sirq-safe-A => hirqs-on/12:failed|failed| ok |
sirq-safe-A => hirqs-on/21:failed|failed| ok |
hard-safe-A + irqs-on/12:failed|failed| ok |
soft-safe-A + irqs-on/12:failed|failed| ok |
hard-safe-A + irqs-on/21:failed|failed| ok |
soft-safe-A + irqs-on/21:failed|failed| ok |
hard-safe-A + unsafe-B #1/123:failed|failed| ok |
soft-safe-A + unsafe-B #1/123:failed|failed| ok |
hard-safe-A + unsafe-B #1/132:failed|failed| ok |
soft-safe-A + unsafe-B #1/132:failed|failed| ok |
hard-safe-A + unsafe-B #1/213:failed|failed| ok |
soft-safe-A + unsafe-B #1/213:failed|failed| ok |
hard-safe-A + unsafe-B #1/231:failed|failed| ok |
soft-safe-A + unsafe-B #1/231:failed|failed| ok |
hard-safe-A + unsafe-B #1/312:failed|failed| ok |
soft-safe-A + unsafe-B #1/312:failed|failed| ok |
hard-safe-A + unsafe-B #1/321:failed|failed| ok |
soft-safe-A + unsafe-B #1/321:failed|failed| ok |
hard-safe-A + unsafe-B #2/123:failed|failed| ok |
soft-safe-A + unsafe-B #2/123:failed|failed| ok |
hard-safe-A + unsafe-B #2/132:failed|failed| ok |
soft-safe-A + unsafe-B #2/132:failed|failed| ok |
hard-safe-A + unsafe-B #2/213:failed|failed| ok |
soft-safe-A + unsafe-B #2/213:failed|failed| ok |
hard-safe-A + unsafe-B #2/231:failed|failed| ok |
soft-safe-A + unsafe-B #2/231:failed|failed| ok |
hard-safe-A + unsafe-B #2/312:failed|failed| ok |
soft-safe-A + unsafe-B #2/312:failed|failed| ok |
hard-safe-A + unsafe-B #2/321:failed|failed| ok |
soft-safe-A + unsafe-B #2/321:failed|failed| ok |
hard-irq lock-inversion/123:failed|failed| ok |
soft-irq lock-inversion/123:failed|failed| ok |
hard-irq lock-inversion/132:failed|failed| ok |
soft-irq lock-inversion/132:failed|failed| ok |
hard-irq lock-inversion/213:failed|failed| ok |
soft-irq lock-inversion/213:failed|failed| ok |
hard-irq lock-inversion/231:failed|failed| ok |
soft-irq lock-inversion/231:failed|failed| ok |
hard-irq lock-inversion/312:failed|failed| ok |
soft-irq lock-inversion/312:failed|failed| ok |
hard-irq lock-inversion/321:failed|failed| ok |
soft-irq lock-inversion/321:failed|failed| ok |
hard-irq read-recursion/123: ok |
soft-irq read-recursion/123: ok |
hard-irq read-recursion/132: ok |
soft-irq read-recursion/132: ok |
hard-irq read-recursion/213: ok |
soft-irq read-recursion/213: ok |
hard-irq read-recursion/231: ok |
soft-irq read-recursion/231: ok |
hard-irq read-recursion/312: ok |
soft-irq read-recursion/312: ok |
hard-irq read-recursion/321: ok |
soft-irq read-recursion/321: ok |
--------------------------------------------------------
144 out of 218 testcases failed, as expected. |
----------------------------------------------------
Calibrating delay loop... 967.47 BogoMIPS (lpj=4837376)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 256
Initializing cgroup subsys blkio
Checking that host ptys support output SIGIO...Yes
Checking that host ptys support SIGIO on close...No, enabling workaround
Using 2.6 host AIO
NET: Registered protocol family 16
bio: create slab <bio-0> at 0
Switching to clocksource itimer
NET: Registered protocol family 1
mconsole (version 2) initialized on /home/michi/.uml/CkIDmD/mconsole
Checking host MADV_REMOVE support...
MADV_REMOVE failed, err = -38
Can't release memory to the host - memory hotplug won't be supported
VFS: Disk quotas dquot_6.5.2
Dquot-cache hash table entries: 512 (order 0, 4096 bytes)
msgmni has been set to 55
io scheduler noop registered
io scheduler deadline registered
io scheduler cfq registered (default)
loop: module loaded
tun: Universal TUN/TAP device driver, 1.6
tun: (C) 1999-2004 Max Krasnyansky <maxk(a)qualcomm.com>
NET: Registered protocol family 17
Initialized stdio console driver
Console initialized on /dev/tty0
Switched to NOHz mode on CPU #0
console [tty0] enabled
Initializing software serial port version 1
console [mc-1] enabled
ubda: unknown partition table
kjournald starting. Commit interval 5 seconds
EXT3-fs (ubda): mounted filesystem with writeback data mode
VFS: Mounted root (ext3 filesystem) readonly on device 98:0.
Program received signal SIGSEGV, Segmentation fault.
bio_list_add (bio=0x61c5ba40) at include/linux/bio.h:414
414 if (bl->tail)
(gdb) backtrace
#0 bio_list_add (bio=0x61c5ba40) at include/linux/bio.h:414
#1 generic_make_request (bio=0x61c5ba40) at block/blk-core.c:1574
#2 0x000000006015c27d in submit_bio (rw=2, bio=0x61c5ba40) at block/blk-core.c:1645
#3 0x00000000600ccff3 in submit_bh (rw=0, bh=0x61808130) at fs/buffer.c:2946
#4 0x00000000600d0e83 in __bread_slow (bdev=<value optimized out>, block=<value optimized out>, size=<value optimized out>)
at fs/buffer.c:1220
#5 __bread (bdev=<value optimized out>, block=<value optimized out>, size=<value optimized out>) at fs/buffer.c:1413
#6 0x000000006012a0c0 in sb_bread (inode=<value optimized out>, depth=1, offsets=0x61c224d0, chain=0x61c22470, err=0x61c224fc)
at include/linux/buffer_head.h:289
#7 ext3_get_branch (inode=<value optimized out>, depth=1, offsets=0x61c224d0, chain=0x61c22470, err=0x61c224fc) at fs/ext3/inode.c:428
#8 0x000000006012affc in ext3_get_blocks_handle (handle=<value optimized out>, inode=0x6180d740, iblock=<value optimized out>,
maxblocks=<value optimized out>, bh_result=<value optimized out>, create=0) at fs/ext3/inode.c:880
#9 0x000000006012b5f4 in ext3_get_block (inode=0x6180d740, iblock=14, bh_result=0x61c226b0, create=16843009) at fs/ext3/inode.c:1038
#10 0x00000000600d729d in do_mpage_readpage (bio=0x61808198, page=<value optimized out>, nr_pages=<value optimized out>,
last_block_in_bio=<value optimized out>, map_bh=0x61c226b0, first_logical_block=0x101010101010101, get_block=0x6012b530 <ext3_get_block>)
at fs/mpage.c:219
#11 0x00000000600d773a in mpage_readpages (mapping=0x6180d878, pages=0x61c22880, nr_pages=18, get_block=<value optimized out>)
at fs/mpage.c:387
#12 0x000000006012a986 in ext3_readpages (file=<value optimized out>, mapping=0x61c5ba40, pages=0x61c5ba40, nr_pages=0)
at fs/ext3/inode.c:1804
#13 0x0000000060081996 in read_pages (mapping=0x6180d878, filp=<value optimized out>, pages=0x61c22880, nr_pages=18) at mm/readahead.c:119
#14 0x0000000060081b94 in __do_page_cache_readahead (mapping=<value optimized out>, filp=<value optimized out>, offset=14,
nr_to_read=<value optimized out>, lookahead_size=<value optimized out>) at mm/readahead.c:199
#15 0x0000000060081bfc in ra_submit (ra=<value optimized out>, mapping=0x2, filp=0x61c5ba40) at mm/readahead.c:256
#16 0x0000000060079869 in do_sync_mmap_readahead (vma=0x61d0b720, vmf=<value optimized out>) at mm/filemap.c:1616
#17 filemap_fault (vma=0x61d0b720, vmf=<value optimized out>) at mm/filemap.c:1681
#18 0x000000006008ebc9 in __do_fault (mm=0x61d08b80, vma=0x61d0b720, address=0, pmd=0x0, pgoff=104, flags=16843009, orig_pte=...)
at mm/memory.c:3185
#19 0x000000006008fde6 in do_linear_fault (mm=0x61c5ba40, vma=0x61d0b720, address=1075965856, pte=<value optimized out>, pmd=0x0,
flags=16843009) at mm/memory.c:3338
#20 handle_pte_fault (mm=0x61c5ba40, vma=0x61d0b720, address=1075965856, pte=<value optimized out>, pmd=0x0, flags=16843009)
at mm/memory.c:3398
#21 0x00000000600909f8 in handle_mm_fault (mm=0x61d08b80, vma=0x61d0b720, address=1075965856, flags=16843009) at mm/memory.c:3503
#22 0x00000000600164f2 in handle_page_fault (address=1075965856, ip=<value optimized out>, is_write=<value optimized out>,
is_user=<value optimized out>, code_out=0x68) at arch/um/kernel/trap.c:68
#23 0x0000000060017321 in maybe_map (addr=<value optimized out>, len=<value optimized out>, is_write=1, op=<value optimized out>,
arg=<value optimized out>) at arch/um/kernel/skas/uaccess.c:47
#24 do_op_one_page (addr=<value optimized out>, len=<value optimized out>, is_write=1, op=<value optimized out>, arg=<value optimized out>)
at arch/um/kernel/skas/uaccess.c:66
#25 0x00000000600174de in buffer_op (addr=1640348224, len=2, is_write=0, op=0, arg=0x68) at arch/um/kernel/skas/uaccess.c:97
#26 0x0000000060017674 in clear_user (mem=0x61c5ba40, len=2) at arch/um/kernel/skas/uaccess.c:227
#27 0x00000000600e5015 in padzero (elf_bss=1640348224) at fs/binfmt_elf.c:106
#28 0x00000000600e57c7 in load_elf_interp (interp_elf_ex=0x61ce5200, interpreter=<value optimized out>,
interp_map_addr=<value optimized out>, no_base=2218976) at fs/binfmt_elf.c:507
---Type <return> to continue, or q <return> to quit---
#29 0x00000000600e6636 in load_elf_binary (bprm=0x61c04280, regs=0x61c20c20) at fs/binfmt_elf.c:883
#30 0x00000000600ab8e9 in search_binary_handler (bprm=0x61c04280, regs=0x61c20c20) at fs/exec.c:1396
#31 0x00000000600ad3f7 in do_execve_common (filename=0x60227e0b "/sbin/init", argv=..., envp=..., regs=0x61c20c20) at fs/exec.c:1522
#32 0x00000000600ad4e9 in do_execve (filename=0x61c5ba40 "\340\\\016", __argv=0x61c5ba40, __envp=0x0, regs=0x0) at fs/exec.c:1569
#33 0x00000000600129b9 in execve1 (file=0x61c5ba40 "\340\\\016", argv=0x61c5ba40, env=0x0) at arch/um/kernel/exec.c:51
#34 0x0000000060012a4d in um_execve (file=0x61c5ba40 "\340\\\016", argv=0x61c5ba40, env=0x0) at arch/um/kernel/exec.c:67
#35 0x0000000060014eab in kernel_execve (filename=0x61c5ba40 "\340\\\016", argv=0x61c5ba40, envp=0x0) at arch/um/kernel/syscall.c:63
#36 0x000000006001256a in run_init_process (init_filename=0x61c5ba40 "\340\\\016") at init/main.c:739
#37 0x00000000600125ca in init_post () at init/main.c:774
#38 0x0000000060001251 in kernel_init (unused=<value optimized out>) at init/main.c:835
#39 0x0000000060024d65 in run_kernel_thread (fn=<value optimized out>, arg=<value optimized out>, jmp_ptr=<value optimized out>)
at arch/um/os-Linux/process.c:268
#40 0x0000000060013f98 in new_thread_handler () at arch/um/kernel/process.c:153
#41 0x0000000000000000 in ?? ()
(gdb) print bl->tail
Cannot access memory at address 0x8
(gdb) list
409
410 static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
411 {
412 bio->bi_next = NULL;
413
414 if (bl->tail)
415 bl->tail->bi_next = bio;
416 else
417 bl->head = bio;
418
(gdb) frame 1
#1 generic_make_request (bio=0x61c5ba40) at block/blk-core.c:1574
1574 bio_list_add(current->bio_list, bio);
(gdb) list
1569 {
1570 struct bio_list bio_list_on_stack;
1571
1572 if (current->bio_list) {
1573 /* make_request is active */
1574 bio_list_add(current->bio_list, bio);
1575 return;
1576 }
1577 /* following loop may be a bit non-obvious, and so deserves some
1578 * explanation.
(gdb)
