Running sg_luns on s390x with CONFIG_DEBUG_PAGEALLOC enabled fails
with EFAULT from the SG_IO ioctl. The EFAULT is the result from
copy_to_user failing in this call chain:
sg_ioctl
sg_new_read
sg_finish_rem_req
blk_rq_unmap_user
__blk_rq_unmap_user
bio_uncopy_user
__bio_copy_iov
copy_to_user
The sg driver calls sg_remove_scat to free the memory pages before
calling blk_rq_unmap_user that tries to copy the data back to
userspace. Change the order to first call blk_rq_unmap_user before
freeing the pages in sg_remove_scat.
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: stable@kernel.org
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
* mark struct vm_area_struct::vm_ops as const
* mark vm_ops in AGP code
But leave TTM code alone, something is fishy there with global vm_ops
being used.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make all seq_operations structs const, to help mitigate against
revectoring user-triggerable function pointers.
This is derived from the grsecurity patch, although generated from scratch
because it's simpler than extracting the changes from there.
Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I overlooked SG_DXFER_TO_FROM_DEV support when I converted sg to use
the block layer mapping API (2.6.28).
Douglas Gilbert explained SG_DXFER_TO_FROM_DEV:
http://www.spinics.net/lists/linux-scsi/msg37135.html
=
The semantics of SG_DXFER_TO_FROM_DEV were:
- copy user space buffer to kernel (LLD) buffer
- do SCSI command which is assumed to be of the DATA_IN
(data from device) variety. This would overwrite
some or all of the kernel buffer
- copy kernel (LLD) buffer back to the user space.
The idea was to detect short reads by filling the original
user space buffer with some marker bytes ("0xec" it would
seem in this report). The "resid" value is a better way
of detecting short reads but that was only added this century
and requires co-operation from the LLD.
=
This patch changes the block layer mapping API to support this
semantics. This simply adds another field to struct rq_map_data and
enables __bio_copy_iov() to copy data from user space even with READ
requests.
It's better to add the flags field and kills null_mapped and the new
from_user fields in struct rq_map_data but that approach makes it
difficult to send this patch to stable trees because st and osst
drivers use struct rq_map_data (they were converted to use the block
layer in 2.6.29 and 2.6.30). Well, I should clean up the block layer
mapping API.
zhou sf reported this regiression and tested this patch:
http://www.spinics.net/lists/linux-scsi/msg37128.htmlhttp://www.spinics.net/lists/linux-scsi/msg37168.html
Reported-by: zhou sf <sxzzsf@gmail.com>
Tested-by: zhou sf <sxzzsf@gmail.com>
Cc: stable@kernel.org
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Commit 5fd29d6ccb ("printk: clean up
handling of log-levels and newlines") changed printk semantics. printk
lines with multiple KERN_<level> prefixes are no longer emitted as
before the patch.
<level> is now included in the output on each additional use.
Remove all uses of multiple KERN_<level>s in formats.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The initial patches to support this through sysfs export were broken
and have been if 0'ed out in any release. So lets just kill the code
and reclaim some space in struct request_queue, if anyone would later
like to fixup the sysfs bits, the git history can easily restore
the removed bits.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block: (153 commits)
block: add request clone interface (v2)
floppy: fix hibernation
ramdisk: remove long-deprecated "ramdisk=" boot-time parameter
fs/bio.c: add missing __user annotation
block: prevent possible io_context->refcount overflow
Add serial number support for virtio_blk, V4a
block: Add missing bounce_pfn stacking and fix comments
Revert "block: Fix bounce limit setting in DM"
cciss: decode unit attention in SCSI error handling code
cciss: Remove no longer needed sendcmd reject processing code
cciss: change SCSI error handling routines to work with interrupts enabled.
cciss: separate error processing and command retrying code in sendcmd_withirq_core()
cciss: factor out fix target status processing code from sendcmd functions
cciss: simplify interface of sendcmd() and sendcmd_withirq()
cciss: factor out core of sendcmd_withirq() for use by SCSI error handling code
cciss: Use schedule_timeout_uninterruptible in SCSI error handling code
block: needs to set the residual length of a bidi request
Revert "block: implement blkdev_readpages"
block: Fix bounce limit setting in DM
Removed reference to non-existing file Documentation/PCI/PCI-DMA-mapping.txt
...
Manually fix conflicts with tracing updates in:
block/blk-sysfs.c
drivers/ide/ide-atapi.c
drivers/ide/ide-cd.c
drivers/ide/ide-floppy.c
drivers/ide/ide-tape.c
include/trace/events/block.h
kernel/trace/blktrace.c
Convert all external users of queue limits to using wrapper functions
instead of poking the request queue variables directly.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
rq->data_len served two purposes - the length of data buffer on issue
and the residual count on completion. This duality creates some
headaches.
First of all, block layer and low level drivers can't really determine
what rq->data_len contains while a request is executing. It could be
the total request length or it coulde be anything else one of the
lower layers is using to keep track of residual count. This
complicates things because blk_rq_bytes() and thus
[__]blk_end_request_all() relies on rq->data_len for PC commands.
Drivers which want to report residual count should first cache the
total request length, update rq->data_len and then complete the
request with the cached data length.
Secondly, it makes requests default to reporting full residual count,
ie. reporting that no data transfer occurred. The residual count is
an exception not the norm; however, the driver should clear
rq->data_len to zero to signify the normal cases while leaving it
alone means no data transfer occurred at all. This reverse default
behavior complicates code unnecessarily and renders block PC on some
drivers (ide-tape/floppy) unuseable.
This patch adds rq->resid_len which is used only for residual count.
While at it, remove now unnecessasry blk_rq_bytes() caching in
ide_pc_intr() as rq->data_len is not changed anymore.
Boaz : spotted missing conversion in osd
Sergei : spotted too early conversion to blk_rq_bytes() in ide-tape
[ Impact: cleanup residual count handling, report 0 resid by default ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Mike Miller <mike.miller@hp.com>
Cc: Eric Moore <Eric.Moore@lsi.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: Mike Miller <mike.miller@hp.com>
Cc: Eric Moore <Eric.Moore@lsi.com>
Cc: Darrick J. Wong <djwong@us.ibm.com>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Merge reason: tracing/core was on a .30-rc1 base and was missing out on
on a handful of tracing fixes present in .30-rc5-almost.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
blk_rq_unmap_user() returns EFAULT if a program passes an invalid
address to kernel (the kernel fails to copy data to user space). sg
needs to pass the returned value to user space instead of ignoring
it. Before the block layer conversion, sg returns EFAULT
properly. This restores the old behavior.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
sg_rq_end_io() is called via rq->end_io. In some rare cases,
sg_rq_end_io calls blk_put_request/blk_rq_unmap_user (when a program
issuing a command has gone before the command completion; e.g. by
interrupting a program issuing a command before the command
completes).
We can't call blk_put_request/blk_rq_unmap_user in interrupt so the
commit c96952ed70 uses
execute_in_process_context().
The problem is that scsi_error_handler() calls rq->end_io too. We
can't call blk_put_request/blk_rq_unmap_user too in this path (we hold
q->queue_lock).
To avoid the above problem, in these rare cases, this patch always
uses schedule_work() instead of execute_in_process_context().
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
- needs to use copy_from_user for iovec before passing it to
blk_rq_map_user_iov().
- before the block layer conversion, if ->dxfer_len and sum of iovec
disagrees, the shorter one wins. However, currently sg returns
-EINVAL. This restores the old behavior.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Most fasync implementations do something like:
return fasync_helper(...);
But fasync_helper() will return a positive value at times - a feature used
in at least one place. Thus, a number of other drivers do:
err = fasync_helper(...);
if (err < 0)
return err;
return 0;
In the interests of consistency and more concise code, it makes sense to
map positive return values onto zero where ->fasync() is called.
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This fixes the following oops:
http://marc.info/?l=linux-kernel&m=123316111415677&w=2
You can reproduce this bug by interrupting a program before a sg
response completes. This leads to the special sg state (the orphan
state), then sg calls blk_put_request in interrupt (rq->end_io).
The above bug report shows the recursive lock problem because sg calls
blk_put_request in interrupt. We could call __blk_put_request here
instead however we also need to handle blk_rq_unmap_user here, which
can't be called in interrupt too.
In the orphan state, we don't need to care about the data transfer
(the program revoked the command) so adding 'just free the resource'
mode to blk_rq_unmap_user is a possible option.
I prefer to avoid complicating the blk mapping API when possible. I
change the orphan state to call sg_finish_rem_req via
execute_in_process_context. We hold sg_fd->kref so sg_fd doesn't go
away until keventd_wq finishes our work. copy_from_user/to_user fails
so blk_rq_unmap_user just frees the resource without the data
transfer.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
sg_io_owned needs to be set before the command is sent to the midlevel;
otherwise, a quickly-completing command may cause a different CPU
to see "srp->done == 1 && !srp->sg_io_owned", which would lead to
incorrect behavior.
Check srp->done and set srp->orphan while holding rq_list_lock to
prevent races with sg_rq_end_io().
There is no need to check sfp->closed from read/write/ioctl/poll/etc.
since the kernel guarantees that this won't happen.
The usefulness of sg_srp_done() was questionable before; now it is
definitely not needed.
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
sg has the following problems related to device removal:
* opening a sg fd races with removing a device
* closing a sg fd races with removing a device
* /proc/scsi/sg/* access races with removing a device
* command completion races with removing a device
* command completion races with closing a sg fd
* can rmmod sg with active commands
These problems can cause kernel oopses, memory-use-after-free, or
double-free errors. This patch fixes these problems by using krefs
to manage the lifetime of sg_device and sg_fd.
Each command submitted to the midlevel holds a reference to sg_fd
until the completion callback. This ensures that sg_fd doesn't go
away if the fd is closed with commands still outstanding.
sg_fd gets the reference of sg_device (with scsi_device) and also
makes sure that the sg module doesn't go away.
/proc/scsi/sg/* functions don't play nicely with krefs because they
give information about sg_fds which have been closed but not yet
freed due to still having outstanding commands and sg_devices which
have been removed but not yet freed due to still being referenced
by one or more sg_fds. To deal with this safely without removing
functionality, /proc functions now access sg_device and sg_fd while
holding a lock instead of using kref_get()/kref_put().
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Hi,
we have run into an issue with blktrace being started for sg devices.
Please apply.
Thanks,
Martin
From: Martin Peschke <mpeschke@linux.vnet.ibm.com>
The device number denoting a generic SCSI devices (sg) in a blktrace
trace is broken; major and minor are always 0. It looks like
sdp->device->sdev_gendev.devt is not initialized properly.
The fix below uses other data to make up a valid device number,
similar to the way an sg device number is generated for sysfs output.
Reported-by: Stefan Raspl <raspl@linux.vnet.ibm.com>
Signed-off-by: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Christof Schmitt
Alexey Dobriyan
James Morris
Michal Schmidt
FUJITA Tomonori
Joe Perches
Jens Axboe
Linus Torvalds
Martin K. Petersen
Tejun Heo
Ingo Molnar
Shawn Du
Jonathan Corbet
Tony Battersby
Martin Peschke