Re: cgdstrategy: divide fault in supervisor mode

[Alexander Nasonov <alnsn%yandex.ru@localhost>]

Michael van Elst wrote:
> Right. This needs to be written differently. Instead of GETCGD_SOFTC()
> use:
> 
> 	cs = getcgd_softc(bp->b_dev);
> 	if (!cs) {
> 		bp->b_error = ENXIO;
> 		biodone(bp);
> 		return;
>     }

I enabled DEBUG in the config and changed cgdstrategy. Same crash:

Stopped in pid 10.1 (mount_ffs) at	netbsd:cgdstrategy+0x2d:	divl
4
0(%r12),%eax

ffffffff808edcd8 <cgdstrategy>:
ffffffff808edcd8:	55                   	push   %rbp
ffffffff808edcd9:	48 89 e5             	mov    %rsp,%rbp
ffffffff808edcdc:	53                   	push   %rbx
ffffffff808edcdd:	48 83 ec 08          	sub    $0x8,%rsp
ffffffff808edce1:	48 89 fb             	mov    %rdi,%rbx
ffffffff808edce4:	f6 05 d5 d0 8e 00 01 	testb  $0x1,0x8ed0d5(%rip)        # ffffffff811dadc0 <cgddebug>
ffffffff808edceb:	75 52                	jne    ffffffff808edd3f <cgdstrategy+0x67>
ffffffff808edced:	48 8b 7b 38          	mov    0x38(%rbx),%rdi
ffffffff808edcf1:	e8 e5 fd ff ff       	callq  ffffffff808edadb <getcgd_softc>
ffffffff808edcf6:	48 89 c7             	mov    %rax,%rdi
ffffffff808edcf9:	48 85 c0             	test   %rax,%rax
ffffffff808edcfc:	74 58                	je     ffffffff808edd56 <cgdstrategy+0x7e>
ffffffff808edcfe:	48 83 7b 48 00       	cmpq   $0x0,0x48(%rbx)
ffffffff808edd03:	8b 4b 34             	mov    0x34(%rbx),%ecx
ffffffff808edd06:	78 11                	js     ffffffff808edd19 <cgdstrategy+0x41>
ffffffff808edd08:	89 c8                	mov    %ecx,%eax
ffffffff808edd0a:	31 d2                	xor    %edx,%edx
ffffffff808edd0c:	f7 77 40             	divl   0x40(%rdi)
ffffffff808edd0f:	85 d2                	test   %edx,%edx
ffffffff808edd11:	75 06                	jne    ffffffff808edd19 <cgdstrategy+0x41>
ffffffff808edd13:	f6 43 40 03          	testb  $0x3,0x40(%rbx)
ffffffff808edd17:	74 18                	je     ffffffff808edd31 <cgdstrategy+0x59>
ffffffff808edd19:	c7 43 20 16 00 00 00 	movl   $0x16,0x20(%rbx)
ffffffff808edd20:	89 4b 24             	mov    %ecx,0x24(%rbx)
ffffffff808edd23:	48 89 df             	mov    %rbx,%rdi
ffffffff808edd26:	48 83 c4 08          	add    $0x8,%rsp
ffffffff808edd2a:	5b                   	pop    %rbx
ffffffff808edd2b:	5d                   	pop    %rbp
ffffffff808edd2c:	e9 f0 c3 fc ff       	jmpq   ffffffff808ba121 <biodone>
ffffffff808edd31:	48 89 de             	mov    %rbx,%rsi
ffffffff808edd34:	48 83 c4 08          	add    $0x8,%rsp
ffffffff808edd38:	5b                   	pop    %rbx
ffffffff808edd39:	5d                   	pop    %rbp
ffffffff808edd3a:	e9 a1 2e 00 00       	jmpq   ffffffff808f0be0 <dk_strategy>
ffffffff808edd3f:	48 63 57 34          	movslq 0x34(%rdi),%rdx
ffffffff808edd43:	48 89 fe             	mov    %rdi,%rsi
ffffffff808edd46:	48 c7 c7 18 15 f9 80 	mov    $0xffffffff80f91518,%rdi
ffffffff808edd4d:	31 c0                	xor    %eax,%eax
ffffffff808edd4f:	e8 4f d8 f8 ff       	callq  ffffffff8087b5a3 <printf>
ffffffff808edd54:	eb 97                	jmp    ffffffff808edced <cgdstrategy+0x15>
ffffffff808edd56:	c7 43 20 06 00 00 00 	movl   $0x6,0x20(%rbx)
ffffffff808edd5d:	eb c4                	jmp    ffffffff808edd23 <cgdstrategy+0x4b>

ffffffff808eeb2e:	48 c7 c7 d8 dc 8e 80 	mov    $0xffffffff808edcd8,%rdi
ffffffff808eeb35:	5b                   	pop    %rbx
ffffffff808eeb36:	41 5c                	pop    %r12
ffffffff808eeb38:	5d                   	pop    %rbp
ffffffff808eeb39:	e9 4f db f4 ff       	jmpq   ffffffff8083c68d <physio>

ffffffff808eeb9d:	48 c7 c7 d8 dc 8e 80 	mov    $0xffffffff808edcd8,%rdi
ffffffff808eeba4:	5b                   	pop    %rbx
ffffffff808eeba5:	41 5c                	pop    %r12
ffffffff808eeba7:	5d                   	pop    %rbp
ffffffff808eeba8:	e9 e0 da f4 ff       	jmpq   ffffffff8083c68d <physio>

Alex