[Klone-users] klone segfaults

[Mark Richards]

thomas fossati wrote:
> Hi Mark,
> 
> On Feb 10, 2008, at 8:23 PM, Mark Richards wrote:
>>
>> When my index.kl1 starts and hits this code it segfaults:
>>
>> # kloned (pid 792) segfaults for page address 00082000 at pc 00097198
> 
> could you please take a look at what's actually happening at pc 00097198 
> (via objdump) ?  Perhaps it's just a matter of uninitialized memory.
> 
> In this regard you could also do something like "struct _sysinfo 
> *sysinfo = NULL;" in the library code and then request explicit 
> initialization by the callers - i.e. "if 
sysinfo == NULL) dbg_err_if
> (_sysinfo_init(&sysinfo));" or similar ...
> 
> ciao, t.
> 
> 
Hi Thomas,

This may quickly devolve into a discussion best put to lang.c :)


It's been quite some time since I've debugged assembler ):}  but I 
managed to get a dump (opposed to taking one).

If you might suggest a method of linking in with symbols, I can then see 
what source is involved.

Here's where it blows:

   kloned (pid 834) segfaults for page address 00000000 at pc 000973ac

97308:	6f9e b4bf 0d00      	move.d 0xdbfb4,$r9
    9730e:	ee9b                	move.d $r9,[$sp]
    97310:	4f9c 6f00           	movu.b 0x6f,$r9
    97314:	04e1 e99b           	move.d $r9,[$sp+4]
    97318:	6f9e f0bf 0d00      	move.d 0xdbff0,$r9
    9731e:	08e1 e99b           	move.d $r9,[$sp+8]
    97322:	6f9e fcbf 0d00      	move.d 0xdbffc,$r9
    97328:	0ce1 e99b           	move.d $r9,[$sp+12]
    9732c:	6f9e e8c0 0d00      	move.d 0xdc0e8,$r9
    97332:	10e1 e99b           	move.d $r9,[$sp+16]
    97336:	7f0d 6c77 0e00 6aaa 	move.d [0xe776c],$r10
    9733e:	47b2                	moveq 7,$r11
    97340:	41c2                	moveq 1,$r12
    97342:	7d86                	clear.d $r13
    97344:	3fbd 6cc6 0b00      	jsr 0xbc66c
    9734a:	7f0d 8c7f 0e00 6aaa 	move.d [0xe7f8c],$r10
    97352:	6fbe 20c1 0d00      	move.d 0xdc120,$r11
    97358:	3fbd 3a4f 0900      	jsr 0x94f3a
    9735e:	7f0d 8c7f 0e00 6aaa 	move.d [0xe7f8c],$r10
    97366:	3fbd 5c6c 0b00      	jsr 0xb6c5c
    9736c:	4192                	moveq 1,$r9
    9736e:	5f8d 76df e99b      	move.d $r9,[$r8-8330]
    97374:	4fac 3200           	movu.b 0x32,$r10
    97378:	3fbd 141c 0800      	jsr 0x81c14
    9737e:	6a96                	move.d $r10,$r9
    97380:	5f8d 06df e99b      	move.d $r9,[$r8-8442]
    97386:	5f8d 06df 6aaa      	move.d [$r8-8442],$r10
    9738c:	4fbc 3200           	movu.b 0x32,$r11
    97390:	6fce fcbf 0d00      	move.d 0xdbffc,$r12
    97396:	6fde 2cc1 0d00      	move.d 0xdc12c,$r13
    9739c:	3fbd b822 0800      	jsr 0x822b8
    973a2:	5f8d 0adf 699a      	move.d [$r8-8438],$r9
    973a8:	1491 a00b           	test.d [$r9+20]
-->>   973ac:	3430                	beq 0x973e2	<<--
    973ae:	0f05                	nop
    973b0:	7f0d 8c7f 0e00 6aaa 	move.d [0xe7f8c],$r10
    973b8:	6fbe 38c1 0d00      	move.d 0xdc138,$r11
    973be:	3fbd 3a4f 0900      	jsr 0x94f3a
    973c4:	6fae 2cc1 0d00      	move.d 0xdc12c,$r10
    973ca:	47b2                	moveq 7,$r11
    973cc:	3fbd 0823 0800      	jsr 0x82308
    973d2:	6fae 48c1 0d00      	move.d 0xdc148,$r10
    973d8:	3fbd ac1f 0800      	jsr 0x81fac
    973de:	24e0                	ba 0x97404
    973e0:	0f05                	nop
    973e2:	7f0d 8c7f 0e00 6aaa 	move.d [0xe7f8c],$r10
    973ea:	6fbe 38c1 0d00      	move.d 0xdc138,$r11
    973f0:	3fbd 3a4f 0900      	jsr 0x94f3a
    973f6:	6fae 2cc1 0d00      	move.d 0xdc12c,$r10
    973fc:	46b2                	moveq 6,$r11

All this said... I managed to solve the problem (although I still don't 
know exactly what's going on) by doing this in my master shared library:

	struct _sysinfo
	{
	  ...
	} sysinfo;

rather than

	struct _sysinfo sysinfo;

This assures me that sysinfo will be global (it's instantiated at the 
top of my master shared library code).

I was incorrect when I stated that the code wasn't breaking in my other 
apps.  Actually, in my other apps, I am not directly accessing a member 
of the structure (only in my Klone app was I attempting this).  Instead, 
I use public functions in the master shared library to do the job.

Is it correct that, should two apps run and each accesses sysinfo, they 
will have separate copies of memory containing the structure and 
therefore not clobber one another?  Seems to me there's a way to 
establish shared memory between apps (never had a need for this) and 
perhaps I have stumbled into this hole?

/m