[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Bug#604627: linux-image-2.6.32-5-amd64: megasas: Failed to alloc kernel SGL buffer for IOCTL



Marc-Christian Petersen <m.c.p@gmx.de> writes:

> I am unable to do short and long tests initiated with smartd/smartctl.
>
> calling 'smartctl -d megaraid,0 /dev/sda -t short' gives:
>
> smartctl 5.40 2010-07-12 r3124 [x86_64-unknown-linux-gnu] (local build)
> Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net
> Short offline self test failed [Cannot allocate memory]
> megasas: Failed to alloc kernel SGL buffer for IOCTL

Please see if this is fixed by the patch I recently posted to the
linux-scsi list: http://permalink.gmane.org/gmane.linux.ide/47847

I believe you are seeing another symptom of the same bug: The driver
happily forwards a 0 length from userspace to dma_alloc_coherent().
smartctl will trigger this when trying to enable the self tests.

I've attached the patch for simplicity.  Note that I haven't yet
received any ack on this, but it did fix the problems for the other user
reporting similar issues.



Bjørn


--- Begin Message ---
The ioc->sgl[i].iov_len value is supplied by the ioctl caller, and can be
zero in some cases.  Assume that's valid and continue without error.

Fixes:

[   69.162538] ------------[ cut here ]------------
[   69.162806] kernel BUG at /build/buildd/linux-2.6.32/lib/swiotlb.c:368!
[   69.163134] invalid opcode: 0000 [#1] SMP
[   69.163570] last sysfs file: /sys/devices/system/cpu/cpu3/cache/index2/shared_cpu_map
[   69.163975] CPU 0
[   69.164227] Modules linked in: fbcon tileblit font bitblit softcursor vga16fb vgastate ioatdma radeon ttm drm_kms_helper shpchp drm i2c_algo_bit lp parport floppy pata_jmicron megaraid_sas igb dca
[   69.167419] Pid: 1206, comm: smartctl Tainted: G        W  2.6.32-25-server #45-Ubuntu X8DTN
[   69.167843] RIP: 0010:[<ffffffff812c4dc5>]  [<ffffffff812c4dc5>] map_single+0x255/0x260
[   69.168370] RSP: 0018:ffff88081c0ebc58  EFLAGS: 00010246
[   69.168655] RAX: 000000000003bffc RBX: 00000000ffffffff RCX: 0000000000000002
[   69.169000] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88001dffe000
[   69.169346] RBP: ffff88081c0ebcb8 R08: 0000000000000000 R09: ffff880000030840
[   69.169691] R10: 0000000000100000 R11: 0000000000000000 R12: 0000000000000000
[   69.170036] R13: 00000000ffffffff R14: 0000000000000001 R15: 0000000000200000
[   69.170382] FS:  00007fb8de189720(0000) GS:ffff88001de00000(0000) knlGS:0000000000000000
[   69.170794] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   69.171094] CR2: 00007fb8dd59237c CR3: 000000081a790000 CR4: 00000000000006f0
[   69.171439] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   69.171784] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[   69.172130] Process smartctl (pid: 1206, threadinfo ffff88081c0ea000, task ffff88081a760000)
[   69.194513] Stack:
[   69.205788]  0000000000000034 00000002817e3390 0000000000000000 ffff88081c0ebe00
[   69.217739] <0> 0000000000000000 000000000003bffc 0000000000000000 0000000000000000
[   69.241250] <0> 0000000000000000 00000000ffffffff ffff88081c5b4080 ffff88081c0ebe00
[   69.277310] Call Trace:
[   69.289278]  [<ffffffff812c52ac>] swiotlb_alloc_coherent+0xec/0x130
[   69.301118]  [<ffffffff81038b31>] x86_swiotlb_alloc_coherent+0x61/0x70
[   69.313045]  [<ffffffffa002d0ce>] megasas_mgmt_fw_ioctl+0x1ae/0x690 [megaraid_sas]
[   69.336399]  [<ffffffffa002d748>] megasas_mgmt_ioctl_fw+0x198/0x240 [megaraid_sas]
[   69.359346]  [<ffffffffa002f695>] megasas_mgmt_ioctl+0x35/0x50 [megaraid_sas]
[   69.370902]  [<ffffffff81153b12>] vfs_ioctl+0x22/0xa0
[   69.382322]  [<ffffffff8115da2a>] ? alloc_fd+0x10a/0x150
[   69.393622]  [<ffffffff81153cb1>] do_vfs_ioctl+0x81/0x410
[   69.404696]  [<ffffffff8155cc13>] ? do_page_fault+0x153/0x3b0
[   69.415761]  [<ffffffff811540c1>] sys_ioctl+0x81/0xa0
[   69.426640]  [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b
[   69.437491] Code: fe ff ff 48 8b 3d 74 38 76 00 41 bf 00 00 20 00 e8 51 f5 d7 ff 83 e0 ff 48 05 ff 07 00 00 48 c1 e8 0b 48 89 45 c8 e9 13 fe ff ff <0f> 0b eb fe 0f 1f 80 00 00 00 00 55 48 89 e5 48 83 ec 20 4c 89
[   69.478216] RIP  [<ffffffff812c4dc5>] map_single+0x255/0x260
[   69.489668]  RSP <ffff88081c0ebc58>
[   69.500975] ---[ end trace 6a2181b634e2abc7 ]---

Reported-by: Bokhan Artem <aptem@ngs.ru>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Cc: stable@kernel.org
---
 drivers/scsi/megaraid/megaraid_sas.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/drivers/scsi/megaraid/megaraid_sas.c b/drivers/scsi/megaraid/megaraid_sas.c
index eb29d50..72713c5 100644
--- a/drivers/scsi/megaraid/megaraid_sas.c
+++ b/drivers/scsi/megaraid/megaraid_sas.c
@@ -4359,6 +4359,11 @@ megasas_mgmt_fw_ioctl(struct megasas_instance *instance,
 	 * For each user buffer, create a mirror buffer and copy in
 	 */
 	for (i = 0; i < ioc->sge_count; i++) {
+		if (ioc->sgl[i].iov_len == 0) {
+			kbuff_arr[i] = NULL;
+			continue;
+		}
+
 		kbuff_arr[i] = dma_alloc_coherent(&instance->pdev->dev,
 						    ioc->sgl[i].iov_len,
 						    &buf_handle, GFP_KERNEL);
-- 
1.7.2.3


--- End Message ---

Reply to: