On Friday 22 August 2008, Boris Petkov wrote: > On Fri, Aug 22, 2008 at 6:45 PM, Nishanth Aravamudan <nacc@xxxxxxxxxx> wrote: > > On 22.08.2008 [12:55:25 +0200], Boris Petkov wrote: > >> On Fri, Aug 22, 2008 at 12:15 PM, Bartlomiej Zolnierkiewicz > >> <bzolnier@xxxxxxxxx> wrote: > >> > On Friday 22 August 2008, Nishanth Aravamudan wrote: > >> >> On 21.08.2008 [16:54:26 -0500], Robin Holt wrote: > >> >> > > [ 32.597792] outsl(496, e000000644678466, 3) > >> >> > ^^^^^^^^^^^^^^^^ > >> >> > > >> >> > This is expected to be an unsigned int * and typecast to that in outsl. > >> >> > Looks like the buffer being passed in is not properly aligned. Time to > >> >> > go look at the caller. Make sure buf is defined as an array of at least > >> >> > int size. That should make this aligned on a 4 byte boundary instead of > >> >> > the 2 byte boundary it is on now. > >> >> > > >> >> > You can cheat at finding the callers by putting > >> >> > WARN_ON(buf & 0x3); > >> >> > printk... > >> >> > >> >> So I tried this and it gets quite hairy quickly (I think) because what's > >> >> unaligned is an IDE command buffer? There is a lot of pointer passing > >> >> and I get lost since I don't know the IDE/elevator code very well. > >> >> > >> >> Here's the stack trace I'm looking at: > >> >> > >> >> [ 5.018347] [<a000000100015420>] show_stack+0x80/0xa0 > >> >> [ 5.018348] sp=e00000130307f930 bsp=e0000013030793b8 > >> >> [ 5.031782] [<a000000100015470>] dump_stack+0x30/0x60 > >> >> [ 5.031783] sp=e00000130307fb00 bsp=e0000013030793a0 > >> >> [ 5.045223] [<a000000100094ff0>] warn_on_slowpath+0x90/0xe0 > >> >> [ 5.045225] sp=e00000130307fb00 bsp=e000001303079378 > >> >> [ 5.059201] [<a000000100517480>] ide_output_data+0x3c0/0x540 > >> >> [ 5.059204] sp=e00000130307fbf0 bsp=e000001303079310 > >> >> [ 5.073248] [<a0000001005309e0>] cdrom_transfer_packet_command+0x2c0/0x340 > >> >> [ 5.073249] sp=e00000130307fbf0 bsp=e0000013030792d0 > >> >> [ 5.088519] [<a000000100530ac0>] cdrom_do_newpc_cont+0x60/0x80 > >> >> [ 5.088522] sp=e00000130307fc00 bsp=e0000013030792b0 > >> >> [ 5.102739] [<a00000010052f1a0>] ide_cd_do_request+0x980/0x1420 > >> >> [ 5.102742] sp=e00000130307fc00 bsp=e000001303079238 > >> >> [ 5.117064] [<a00000010050fe00>] ide_do_request+0xca0/0x1d00 > >> >> [ 5.117066] sp=e00000130307fc00 bsp=e0000013030791a0 > >> >> [ 5.131105] [<a000000100511580>] do_ide_request+0x40/0x60 > >> >> [ 5.131107] sp=e00000130307fc30 bsp=e000001303079180 > >> >> [ 5.144897] [<a000000100384780>] elv_insert+0x280/0x5c0 > >> >> [ 5.144900] sp=e00000130307fc30 bsp=e000001303079148 > >> >> [ 5.158507] [<a000000100384c40>] __elv_add_request+0x180/0x240 > >> >> [ 5.158509] sp=e00000130307fc30 bsp=e000001303079110 > >> >> [ 5.172733] [<a000000100391730>] blk_execute_rq_nowait+0xd0/0x1e0 > >> >> [ 5.172734] sp=e00000130307fc30 bsp=e0000013030790d0 > >> >> [ 5.187220] [<a000000100391910>] blk_execute_rq+0xd0/0x240 > >> >> [ 5.187221] sp=e00000130307fc30 bsp=e000001303079090 > >> >> [ 5.201091] [<a000000100531f70>] ide_cd_queue_pc+0x130/0x2e0 > >> >> [ 5.201093] sp=e00000130307fcc0 bsp=e000001303078fd0 > >> >> [ 5.215137] [<a0000001005342f0>] ide_cdrom_packet+0x130/0x180 > >> >> [ 5.215139] sp=e00000130307fd00 bsp=e000001303078f78 > >> >> [ 5.229281] [<a000000100593080>] cdrom_mode_sense+0xc0/0xe0 > >> >> [ 5.229283] sp=e00000130307fd10 bsp=e000001303078f40 > >> >> [ 5.243239] [<a00000010052d9c0>] ide_cdrom_get_capabilities+0x80/0xc0 > >> >> [ 5.243240] sp=e00000130307fd10 bsp=e000001303078f10 > >> >> [ 5.258084] [<a000000100533890>] ide_cd_probe+0x810/0xf40 > >> >> [ 5.258086] sp=e00000130307fd50 bsp=e000001303078e90 > >> >> [ 5.273709] [<a00000010050a510>] generic_ide_probe+0x70/0xa0 > >> >> [ 5.273711] sp=e00000130307fdc0 bsp=e000001303078e70 > >> >> [ 5.287774] [<a0000001004bdaf0>] driver_probe_device+0x190/0x3a0 > >> >> [ 5.287775] sp=e00000130307fdc0 bsp=e000001303078e28 > >> >> [ 5.302163] [<a0000001004bdd80>] __driver_attach+0x80/0xe0 > >> >> [ 5.302164] sp=e00000130307fdc0 bsp=e000001303078de8 > >> >> [ 5.316032] [<a0000001004bc5a0>] bus_for_each_dev+0xc0/0x140 > >> >> [ 5.316034] sp=e00000130307fdc0 bsp=e000001303078db0 > >> >> [ 5.330072] [<a0000001004bd700>] driver_attach+0x40/0x60 > >> >> [ 5.330074] sp=e00000130307fde0 bsp=e000001303078d90 > >> >> [ 5.343761] [<a0000001004bd290>] bus_add_driver+0x370/0x4a0 > >> >> [ 5.343763] sp=e00000130307fde0 bsp=e000001303078d48 > >> >> [ 5.357720] [<a0000001004be3d0>] driver_register+0xd0/0x340 > >> >> [ 5.357721] sp=e00000130307fde0 bsp=e000001303078d00 > >> >> [ 5.371693] [<a0000001009a3ea0>] ide_cdrom_init+0x20/0x40 > >> >> [ 5.371695] sp=e00000130307fde0 bsp=e000001303078ce8 > >> >> [ 5.385475] [<a00000010000a5a0>] do_one_initcall+0x60/0x380 > >> >> [ 5.385477] sp=e00000130307fde0 bsp=e000001303078ca8 > >> >> [ 5.399445] [<a0000001009645b0>] kernel_init+0x370/0x420 > >> >> [ 5.399447] sp=e00000130307fe20 bsp=e000001303078c68 > >> >> [ 5.413148] [<a000000100013590>] kernel_thread_helper+0xd0/0x100 > >> >> [ 5.413149] sp=e00000130307fe30 bsp=e000001303078c40 > >> >> [ 5.427547] [<a00000010000a4c0>] start_kernel_thread+0x20/0x40 > >> >> [ 5.427548] sp=e00000130307fe30 bsp=e000001303078c40 > >> >> > >> >> We are trying to send a sense command to the device and the buffer we > >> >> use (which is rq->cmd) is what is unaligned, I believe. I'm not sure how > >> >> useful I can be going forward... > >> > > >> > Borislav/Fujita, any ideas what is going wrong with ide-cd? > >> > > >> > >> I think its the following: > >> > >> ide_cdrom_get_capabilities() allocates a struct packet_command cgc on > >> the stack in order to do cdrom_mode_sense() later on. Since that cmd > >> is not 4byte aligned as we've seen above and we don't do the alignment > >> check in ide_cd_queue_pc() similar to cdrom_do_block_pc() (see > >> 0b6abc17700a7843b165c677da0ac94522f83083), we bust the transfer later. > >> > >> I'll cook up something later when I have the time... > > > > I'm happy to test any patches (and it should be relatively quick to > > test). > > Sure, however, the problem is more hairy than I expected - the rq->cmd buffer > is received through blk_get_request() and it is sometimes 2 bytes aligned and > not 4. Bart, is it a sensible approach to do an ia64 ifdef that checks the > alignment of the buffer and turns off drive->io_32bit which is checked in > ide_output_data() thus doing only out(w|b) accesses on ia64 with misaligned > buffers? Well, it sounds kind of like a hack if I have to answer honestly. ;-) Why not just make rq->cmd always properly aligned in the block layer i.e. by allocating BLK_MAX_CDB + 2 instead of BLK_MAX_CDB for rq->__cmd and then doing ALIGN() when setting rq->cmd in blk_rq_init()? [ I'm sure there exists even better solution... ] Thanks, Bart -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
