From mboxrd@z Thu Jan  1 00:00:00 1970
Message-Id: <1B2326AB-19A1-4C73-9BA6-0033FA0191F8@ar.aichi-u.ac.jp>
From: Kenji Arisawa <arisawa@ar.aichi-u.ac.jp>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
In-Reply-To: <dd6fe68a0908110827t5b32ef44r2b8f3645ae8f12de@mail.gmail.com>
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Date: Wed, 12 Aug 2009 15:48:40 +0900
References: <db54ced81720f4ae901ffb396e8c9fb3@quanstro.net>
	<7ED1969C-3B1B-4FE4-8E2D-5B486E636E26@ar.aichi-u.ac.jp>
	<dd6fe68a0908110827t5b32ef44r2b8f3645ae8f12de@mail.gmail.com>
Subject: Re: [9fans] validateaddress
Topicbox-Message-UUID: 43ddad08-ead5-11e9-9d60-3106f5b1d025


Thanks Russ,

ar% ps
...
none        1236297 49979:50   0:00      172K Running  validateaddress
...
ar% acid 1236297
/proc/1236297/text:386 plan 9 executable
/sys/lib/acid/port
/sys/lib/acid/386
acid: bpset(strcmp)
Waiting...
1236297: exception 50	klook+0x7a	MOVL	0x8(DX),DX
acid: loop 1,20 do { cont(); print("strcmp '", *(*strcmp:s1\s), "'
'",*(*strcmp:s2\s), "'\n"); }
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

1236297: breakpoint	strcmp+0x3	MOVL	s1+0x0(FP),BP
1236297: breakpoint	strcmp	SUBL	$0xc,SP
strcmp 'in' 'prompt'

acid: acid: bpdel(strcmp)
acid: bpset(klook)
acid: cont();
<stdin>:5: (error) msg: pid=1236297 startstop: interrupted
acid: bpdel(klook)


Kenji Arisawa


On 2009/08/12, at 0:27, Russ Cox wrote:

> acid pid
>
> bpset(strcmp)
> loop 1,20 do { cont(); print("strcmp '", *(*strcmp:s1\s), "' '",
> *(*strcmp:s2\s), "'\n"); }
> bpdel(strcmp)
>
> also
>
> bpset(klook)
> cont();
> # wait a while, see if you hit the breakpoint, probably not
> DEL (to stop acid if it didn't hit the breakpoint)
> bpdel(klook)
>
> if you do hit the klook breakpoint then try
> the same sequence but with yyparse instead
> of klook.
>
> the goal is to find some function that isn't being
> repeatedly called.  that helps narrow down the
> source of the infinite loop to code inside that
> function or the ones it calls.
>
> russ
>