Re: Compiling ext2fs.static with pthreads

[Thomas Thomas]

> Hi!

Howdy.

>On Sun, 6 May 2012 09:25:11 -0700 (PDT), Thomas Thomas <ricinwich@yahoo.com> 
>wrote:
>> I played around and got it to compile, though how I did so is a nasty hack.

>What kind of?

I caught the output of make to get the full compile command and added
../libpthread/cancel-cond.o into it manually, and saved it as a shell script.
Barry, or someone, rewrote cancel-cond.c from cthreads into a pthreads one.
I called it nasty because it doesn't fix the makefile, which would be the clean
solution.

So, it runs as a translator. Spews out some unexpected debugging info that Barry
added, but I can add files, delete files, list directories, etc. I haven't 
tested it under
load, however. Thank you for the link on debugging translators. I tried to 
start a
sub-hurd using it, but for some reason it gets to somewhere in libc while 
trying to
create its first thread and derefs a null pointer. I don't have complete 
debugging info
for where it falls apart. Here's the backtrace:

#0 0x080d0366 in _hurd_sigstate_lock ()
#1 0x0805a570 in __pthread_sigstate ()
#2 0x080598d8 in __pthread_create_internal ()
#3 0x08059b67 in pthread_create ()
#4 0x0805b522 in diskfs_start_disk_pager (upi=0x81e0d48,
    pager_bucket=0x81e0d58, may_cache=1, notify_on_evict=1, size=268435456,
    image=0x81c1ec4) at disk-pager.c:60
#5 0x08054036 in create_disk_pager () at pager.c:1203
#6 0x0804826b in main (argc=7, argv=0x3ffe78) at ext2fs.c:186

and the offending instruction is (x/i $pc)

=> 0x80d0366 <_hurd_sigstate_lock+70>: xchg %eax,0x4(%edx)

So, with (x/i $pc-8), I find
0x80d035e <_hurd_sigstate_lock+62>: mov $0x1,%eax
This looks to me to be the mutex lock code, though I am not good at x86 
assembly,
and don't know where the previous instruction could be (but then again, no one 
can).
I want to blame cthreads dependencies in libc, because that is the easy 
solution.


Sorry for all this, I have the desire to prove that I am not Completely 
Incompetent,
Thomas D