Re: [9fans] a question on APE

["ron minnich" <rminnich@gmail.com>]

On Dec 17, 2007 11:54 PM, Kernel Panic <cinap_lenrek@gmx.de> wrote:

> Ahh... just looked at the code...
> Ok, as i expected... recv() calls a different read() from
> /sys/src/libc/9sys/read.c. It will all work if
> recv() would call the thing from this one:
> /sys/src/ape/lib/ap/plan9/read.c.

I'm not seeing that. I would be happy if you are right but I can't confirm it.

I run acid on the binary:
recv 0x000cd7b6	SUBL	$0x10,SP
recv+0x3 0x000cd7b9	MOVL	flags+0xc(FP),AX
recv+0x7 0x000cd7bd	ANDL	$0x1,AX
recv+0xa 0x000cd7c0	CMPL	AX,$0x0
recv+0xd 0x000cd7c3	JEQ	recv+0x22(SB)
recv+0xf 0x000cd7c5	MOVL	$0x29,errno(SB)
recv+0x19 0x000cd7cf	MOVL	$0xffffffff,AX
recv+0x1e 0x000cd7d4	ADDL	$0x10,SP
recv+0x21 0x000cd7d7	RET
recv+0x22 0x000cd7d8	MOVL	fd+0x0(FP),CX
recv+0x26 0x000cd7dc	MOVL	CX,0x0(SP)
recv+0x29 0x000cd7df	MOVL	a+0x4(FP),CX
recv+0x2d 0x000cd7e3	MOVL	CX,0x4(SP)
recv+0x31 0x000cd7e7	MOVL	n+0x8(FP),CX
recv+0x35 0x000cd7eb	MOVL	CX,0x8(SP)
recv+0x39 0x000cd7ef	CALL	read(SB)
recv+0x3e 0x000cd7f4	ADDL	$0x10,SP
recv+0x41 0x000cd7f7	RET

so it calls read.

Read is this:
read 0x000c3834	SUBL	$0x28,SP
read+0x3 0x000c3837	MOVL	nbytes+0x8(FP),DI
read+0x7 0x000c383b	MOVL	buf+0x4(FP),SI
read+0xb 0x000c383f	MOVL	d+0x0(FP),BX
read+0xf 0x000c3843	CMPL	BX,$0x0
read+0x12 0x000c3846	JLT	read+0x19(SB)
read+0x14 0x000c3848	CMPL	BX,$0x60
read+0x17 0x000c384b	JLT	read+0x2c(SB)
read+0x19 0x000c384d	MOVL	$0x4,errno(SB)
read+0x23 0x000c3857	MOVL	$0xffffffff,AX
read+0x28 0x000c385c	ADDL	$0x28,SP
read+0x2b 0x000c385f	RET
read+0x2c 0x000c3860	LEAL	0x0(BX)(BX*4),CX
read+0x2f 0x000c3863	SHLL	$0x2,CX
read+0x32 0x000c3866	LEAL	_fdinfo(SB)(CX*1),AX
read+0x39 0x000c386d	MOVL	0x0(AX),AX
read+0x3b 0x000c386f	ANDL	$0x2,AX
read+0x3e 0x000c3872	CMPL	AX,$0x0
read+0x41 0x000c3875	JEQ	read+0x19(SB)
read+0x43 0x000c3877	CMPL	DI,$0x0
read+0x46 0x000c387a	JHI	read+0x4e(SB)
read+0x48 0x000c387c	XORL	AX,AX
read+0x4a 0x000c387e	ADDL	$0x28,SP
read+0x4d 0x000c3881	RET
read+0x4e 0x000c3882	CMPL	SI,$0x0
read+0x51 0x000c3885	JNE	read+0x66(SB)
read+0x53 0x000c3887	MOVL	$0x9,errno(SB)
read+0x5d 0x000c3891	MOVL	$0xffffffff,AX
read+0x62 0x000c3896	ADDL	$0x28,SP
read+0x65 0x000c3899	RET

which is the ape version. There is only one read symbol in the binary,
and it's a T.

So I am not convinced the recv is calling the wrong thing. That said,
I'm still going to change it in source to see what happens :-)

ron