Frederik Himpe reported an unkillable and un-straceable pan process.
Zero length iovecs can go into an infinite loop in writev, because the
iovec iterator does not always advance over them.
The sequence required to trigger this is not trivial. I think it
requires that a zero-length iovec be followed by a non-zero-length iovec
which causes a pagefault in the atomic usercopy. This causes the writev
code to drop back into single-segment copy mode, which then tries to
copy the 0 bytes of the zero-length iovec; a zero length copy looks like
a failure though, so it loops.
Put a test into iov_iter_advance to catch zero-length iovecs. We could
just put the test in the fallback path, but I feel it is more robust to
skip over zero-length iovecs throughout the code (iovec iterator may be
used in filesystems too, so it should be robust).
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since this is used only in idetape_blkdev_ioctl(), remove the typedef and make
the struct function-local.
Bart:
- s/sizeof(struct idetape_config)/sizeof(config)/
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
idetape_active_next_stage() was rather ambiguous wrt its purpose. Make that
more explicit and remove superfluous comment.
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
ide-tape has depended on EXPERIMENTAL for ages. Change that since the driver is
being only maintained now.
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
They seem just to sit there completely unused.
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Also, shorten function name idetape_get_blocksize_from_block_descriptor() and
move its definition up thereby getting rid of its forward declaration.
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
There should be no functional changes resulting from this patch.
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
There should be no functional changes resulting from this patch.
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
There should be no functional changes resulting from this patch.
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
All those 2-byte values denoting the different capabilities are being written to
the local copy of the caps buffer without being converted to big endian for
simplicity of usage and shorter code later. Also, we add some comments stating
which are the fields of the caps page in question in order to alleviate the
cryptic pointer casting exercises as in e.g. idetape_get_mode_sense_results().
There should be no functional changes resulting from this patch.
Bart:
- remove two needless "!!"
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
The device capabilities are probed for during device initialization so this
info is available through proc/ioctl() und it is redundant here.
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
No reason to use ide_init_hwif_ports() in ide-cs (as a nice side-effect
this makes ide-cs work on archs that don't define IDE_ARCH_OBSOLETE_INIT).
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* Move check_dma_crc() to ide-dma.c and add inline version for
CONFIG_BLK_DEV_IDEDMA=n case.
* Rename check_dma_crc() to ide_check_dma_crc().
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
SELECT_DRIVE() is called by IDE core code in start_request() before device
driver's ->do_request method. In ide-scsi case ->do_request is implemented
by idescsi_do_request() which is also the only user of idescsi_issue_pc().
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* Use __ide_set_handler() in ide_execute_command().
While at it:
* Fix whitespace damage in ide_execute_command().
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* siimage.c: use hwif->sata_scr[SATA_{ERROR,STATUS}_OFFSET] instead of
SATA_{ERROR,STATUS}_REG macros.
* Remove no longer needed SATA_*_REG macros.
While at it:
* Remove needless SATA Status register read from sil_sata_reset_poll().
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* ->nice0 and ->nice2 ide_drive_t fields are always zero so remove them.
* IDE_NICE_0 and IDE_NICE_2 defines from <linux/hdreg.h> are no longer
used by any kernel code so cover them with #ifndef/#endif __KERNEL__.
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* Cache value read from the Status register in 'stat' variable in do_probe()
and enable_nest(), then remove remove needless Status register reads.
While at it:
* Add proper KERN_* levels to printk() calls.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* Un-static create_proc_ide_drives() and call it from ide_device_add_all().
While at it:
* Rename create_proc_ide_drives() to ide_proc_port_register_devices().
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Move hwif->present check out from ide_proc_register_port() to
ide_device_add_all().
There should be no functionality changes caused by this patch.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* Factor out devices setup from ide_acpi_init() to
ide_acpi_port_init_devices().
* Call ide_acpi_port_init_devices() in ide_device_add_all().
While at it:
* Remove no longer needed 'drive' field from struct ide_acpi_drive_link.
There should be no functionality changes caused by this patch.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
