Commit Graph

6 Commits

Author SHA1 Message Date
brking@us.ibm.com
521314c122 [SCSI] sg: Command completion after remove oops
A problem exists todayin the sg driver that if an SG_IO request is
outstanding to a device when it is removed from the system. The
system may oops if that command completes later in time.

1. sg_remove gets called
2. sg_remove calls sg_finish_req_req on all pending requests
   This removes the Sg_request's from the headrp list in the Sg_fd
3. The sleeping SG_IO ioctl is woken. It does nothing and returns.
4. The caller closes the fd, which invokes sg_release
5. sg_release calls sg_remove_sfp. It finds no outstanding commands
   since the headrp list is empty, so it calls __sg_remove_sfp,
   which frees the sfp.
6. Now when sg_cmd_done gets called, sg uses upper_private_data in
   the Scsi_Request, which should point to the srp, which has been
   freed, so it points to freed memory.
7. sg then dereferences the srp pointer to get the sfp, and we oops.

The fix is to NULL out the upper_private_data field in this path,
which sg_cmd_done already checks for, which will prevent the oops
from occurring.

cpu 0x1: Vector: 300 (Data Access) at [c00000000fff7aa0]
    pc: d0000000002bbea8: .sg_cmd_done+0x70/0x394 [sg]
    lr: d000000000073304: .scsi_finish_command+0x10c/0x130 [scsi_mod]
    sp: c00000000fff7d20
   msr: 8000000000009032
   dar: 2f70726f63202f78
 dsisr: 40000000
  current = 0xc0000000024589b0
  paca    = 0xc0000000003da800
    pid   = 7, comm = events/1
[c00000000fff7dc0] d000000000073304 .scsi_finish_command+0x10c/0x130 [scsi_mod]
[c00000000fff7e50] d00000000007317c .scsi_softirq+0x140/0x168 [scsi_mod]
[c00000000fff7ef0] c0000000000634dc .__do_softirq+0xa0/0x17c
[c00000000fff7f90] c000000000018430 .call_do_softirq+0x14/0x24
[c00000000ed472e0] c0000000000142e0 .do_softirq+0x74/0x9c
[c00000000ed47370] c000000000013c9c .do_IRQ+0xe8/0x100
[c00000000ed473f0] c00000000000ae34 HardwareInterrupt_entry+0x8/0x54

c00000000003df28 .smp_call_function+0
x100/0x1d0
[c00000000ed47780] c0000000000ba99c .invalidate_bh_lrus+0x30/0x70
[c00000000ed47810] c0000000000b91a0 .invalidate_bdev+0x18/0x3c
[c00000000ed478a0] c0000000000da7b8 .__invalidate_device+0x70/0x94
[c00000000ed47930] c0000000001d40bc .invalidate_partition+0x4c/0x7c
[c00000000ed479c0] c00000000010a944 .del_gendisk+0x48/0x15c
[c00000000ed47a50] d00000000003d55c .sd_remove+0x34/0xe4 [sd_mod]
[c00000000ed47ae0] c0000000001c5d30 .device_release_driver+0x90/0xb4
[c00000000ed47b70] c0000000001c6130 .bus_remove_device+0xb0/0x12c
[c00000000ed47c00] c0000000001c4378 .device_del+0x120/0x198
[c00000000ed47ca0] d00000000007dcdc .scsi_remove_device+0xb4/0x194 [scsi_mod]
[c00000000ed47d30] d0000000000a5864 .ipr_worker_thread+0x1d4/0x27c [ipr]
[c00000000ed47dd0] c0000000000734c4 .worker_thread+0x238/0x2f4
[c00000000ed47ee0] c0000000000796c0 .kthread+0xcc/0x11c
[c00000000ed47f90] c000000000018ad0 .kernel_thread+0x4c/0x6c

Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-06-03 12:25:35 -05:00
be7db055dd [PATCH] remove old scsi data direction macros
these have been wrappers for the generic dma direction bits since 2.5.x.
This patch converts the few remaining drivers and removes the macros.

Arjan noticed there's some hunk in here that shouldn't.  Updated patch
below:

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-04-18 13:49:58 -05:00
James Bottomley
c46f2ffb9e merge by hand (scsi_device.h) 2005-04-18 13:45:00 -05:00
db9dff366b [PATCH] remove outdated print_* functions
We have the scsi_print_* functions in the proper namespace for a long
time now and there weren't a lot users left.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-04-18 12:32:20 -05:00
cb59e84083 [PATCH] sg.c: update
The attachment combines the most recent patch from
Yum Rayan <yum.rayan@gmail.com> (to reduce sg stack
usage), Adrian Bunk <bunk@stusta.de> (to fix check
after use) and me (fix elapsed time calculation
(duration) on ia64 machines).

I have modified the patch from Yum Rayan so kmalloc()
in sg_read() is only called for the (rare) code paths
that need them.

Changelog:
   - reduce stack usage in sg_ioctl() and sg_read()
   - fix check after use in sg_mmap()
   - hold duration internally in milliseconds and
     check current time later than held time

Signed-off-by: Douglas Gilbert <dougg@torque.net>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-04-16 20:08:52 -05:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00