Commit Graph

17 Commits

Author SHA1 Message Date
Wolfgang Ocker
aaacf4bb51 spi: avoid spidev crash when device is removed
I saw a kernel oops in spidev_remove() when a spidev device was registered
and I unloaded the SPI master driver:

Unable to handle kernel paging request for data at address 0x00000004
Faulting instruction address: 0xc01c0c50
Oops: Kernel access of bad area, sig: 11 [#1]
CDSPR
Modules linked in: spi_ppc4xx(-)
NIP: c01c0c50 LR: c01bf9e4 CTR: c01c0c34
REGS: cec89c30 TRAP: 0300   Not tainted  (2.6.27.3izt)
MSR: 00021000 <ME>  CR: 24000228  XER: 20000007
DEAR: 00000004, ESR: 00800000
TASK = cf889040[2070] 'rmmod' THREAD: cec88000
GPR00: 00000000 cec89ce0 cf889040 cec8e000 00000004 cec8e000 ffffffff 00000000
GPR08: 0000001c c0336380 00000000 c01c0c34 00000001 1001a338 100e0000 100df49c
GPR16: 100b54c0 100df49c 100ddd20 100f05a8 100b5340 100efd68 00000000 00000000
GPR24: 100ec008 100f0428 c0327788 c0327794 cec8e0ac cec8e000 c0336380 00000000
NIP [c01c0c50] spidev_remove+0x1c/0xe4
LR [c01bf9e4] spi_drv_remove+0x2c/0x3c
Call Trace:
[cec89d00] [c01bf9e4] spi_drv_remove+0x2c/0x3c
[cec89d10] [c01859a0] __device_release_driver+0x78/0xb4
[cec89d20] [c0185ab0] device_release_driver+0x28/0x44
[cec89d40] [c0184be8] bus_remove_device+0xac/0xd8
[cec89d60] [c0183094] device_del+0x100/0x194
[cec89d80] [c0183140] device_unregister+0x18/0x30
[cec89da0] [c01bf30c] __unregister+0x20/0x34
[cec89db0] [c0182778] device_for_each_child+0x38/0x74
[cec89de0] [c01bf2d0] spi_unregister_master+0x28/0x44
[cec89e00] [c01bfeac] spi_bitbang_stop+0x1c/0x58
[cec89e20] [d908a5e0] spi_ppc4xx_of_remove+0x24/0x7c [spi_ppc4xx]
[...]

IMHO a call to spi_set_drvdata() is missing in spidev_probe(). The patch
below helped.

Signed-off-by: Wolfgang Ocker <weo@reccoware.de>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-01 19:55:24 -08:00
Greg Kroah-Hartman
a9b12619f7 device create: misc: convert device_create_drvdata to device_create
Now that device_create() has been audited, rename things back to the
original call to be sane.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-16 09:24:43 -07:00
Alan Cox
4ef754b7d7 spidev: BKL removal
Another step to removing ->ioctl and to removing the BKL

[dbrownell@users.sourceforge.net: take final step; BKL not needed]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:30 -07:00
David Brownell
3d81252ddb device create: spi: convert device_create to device_create_drvdata
Switch over to use the shiny new device_create_drvdata() call
instead of the original device_create() calls, so this continues
to work after device_create() is  removed.

Note that this driver never had the race which motivated removing
the original call; it locked correctly.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-21 21:54:45 -07:00
Jonathan Corbet
2fceef397f Merge commit 'v2.6.26' into bkl-removal 2008-07-14 15:29:34 -06:00
Sebastian Siewior
4b1295b0df spi: fix the read path in spidev
This got broken by the recent "fix rmmod $spi_driver while spidev-user is
active".  I tested the rmmod & write path but didn't check the read path.
I am sorry.  The read logic changed and spidev_sync_read() +
spidev_sync_write() do not return zero on success anymore but the number
of bytes that has been transfered over the bus.  This patch changes the
logic and copy_to_user() gets called again.

The write path returns the number of bytes which are written to the
underlying device what may be less than the requested size.  This patch
makes the same change to the read path or else we request a read of 20
bytes, get 10, don't call copy to user and report to the user that we read
10 bytes.

[akpm@linux-foundation.org: remove test of known-to-be-zero local]
Signed-off-by: Sebastian Siewior <bigeasy@linutronix.de>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-04 10:40:08 -07:00
Jonathan Corbet
609f9e92b5 spidev: BKL pushdown
Add the BKL to spidev_open(), even though the existing locking looks
adequate.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2008-06-20 14:05:50 -06:00
David Brownell
b2c8daddcb spi: fix refcount-related spidev oops-on-rmmod
This addresses other oopsing paths in "spidev" by changing how it manages
refcounting.  It decouples the lifecycle of the per-device data from the
class device (not just the spi device):

  - Use class_{create,destroy} not class_{register,unregister}.
  - Use device_{create,destroy} not device_{register,unregister}.
  - Free the per-device data only when TWO conditions are true:
      * Driver is unbound from underlying SPI device, and
      * Device is no longer open (new)

Also, spi_{get,set}_drvdata not dev_{get,set}_drvdata for simpler code.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Sebastian Siewior <bigeasy@tglx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-06 11:29:08 -07:00
David Brownell
25d5cb4b03 spi: remove some spidev oops-on-rmmod paths
Somehow the spidev code forgot to include a critical mechanism: when the
underlying device is removed (e.g.  spi_master rmmod), open file
descriptors must be prevented from issuing new I/O requests to that
device.  On penalty of the oopsing reported by Sebastian Siewior
<bigeasy@tglx.de> ...

This is a partial fix, adding handshaking between the lower level (SPI
messaging) and the file operations using the spi_dev.  (It also fixes an
issue where reads and writes didn't return the number of bytes sent or
received.)

There's still a refcounting issue to be addressed (separately).

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Reported-by: Sebastian Siewior <bigeasy@tglx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-24 09:56:14 -07:00
Al Viro
142956af52 fix abuses of ptrdiff_t
Use of ptrdiff_t in places like

-                       if (!access_ok(VERIFY_WRITE, u_tmp->rx_buf, u_tmp->len))
+                       if (!access_ok(VERIFY_WRITE, (u8 __user *)
+                                               (ptrdiff_t) u_tmp->rx_buf,
+                                               u_tmp->len))

is wrong; for one thing, it's a bad C (it's what uintptr_t is for; in general
we are not even promised that ptrdiff_t is large enough to hold a pointer,
just enough to hold a difference between two pointers within the same object).
For another, it confuses the fsck out of sparse.

Use unsigned long or uintptr_t instead.  There are several places misusing
ptrdiff_t; fixed.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-29 07:41:33 -07:00
David Brownell
96ddbf504a spidev warning fix
Git rid of "warning: passing arg 2 of `access_ok' makes pointer from integer
without a cast" reported on SH ...  most architectures use macros in that
test, SH uses inlined functions.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-11 15:47:42 -07:00
Anton Vorontsov
6f166e3833 spidev supports more communications modes
The spidev driver doesn't currently expose all SPI communications modes to
userspace.  This passes them all through to the driver.

Two of them are potentially troublesome, in the sense that they could cause
hardware conflicts on shared busses.  It might be appropriate to add some
privilege checks for for those modes.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31 15:39:40 -07:00
David Brownell
4917d92780 spidev compiler warning gone
Get rid of annoying GCC warning on 32-bit platforms.

drivers/spi/spidev.c: In function 'spidev_message':
drivers/spi/spidev.c:184: warning: cast to pointer from integer of different size
drivers/spi/spidev.c:216: warning: cast to pointer from integer of different size

The trick is to add an extra cast using "ptrdiff_t" to convert the u64 to
the correct size integer, and only then casting it into a "void *" pointer.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:04 -07:00
Florin Malita
9bea3f29fc spi: potential memleak in spidev_ioctl
'ioc' should be deallocated if __copy_from_user fails (found by Coverity
- CID 1644).

Signed-off-by: Florin Malita <fmalita@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-23 20:14:12 -07:00
Domen Puncer
da90fa8ff6 spi/spidev: check message size before copying
Message size needs to be checked before copying, or bad things could
happen.

Signed-off-by: Domen Puncer <domen.puncer@telargo.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-23 20:14:12 -07:00
Domen Puncer
0a4dd7783d spi: fix spidev for >sizeof(long)/32 devices
find_first_zero_bit accepts number of bits, not longs.

Signed-off-by: Domen Puncer <domen.puncer@telargo.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-16 21:19:15 -07:00
Andrea Paterniani
814a8d50eb /dev/spidevB.C interface
Add a filesystem API for <linux/spi/spi.h> stack.  The initial version of
this interface is purely synchronous.

dbrownell@users.sourceforge.net:

 Cleaned up, bugfixed; much simplified; added preliminary documentation.

 Works with mdev given CONFIG_SYSFS_DEPRECATED; and presumably udev.

 Updated SPI_IOC_MESSAGE ioctl to full spi_message semantics, supporting
 groups of one or more transfers (each of which may be full duplex if
 desired).

 This is marked as EXPERIMENTAL with an explicit disclaimer that the API
 (notably the ioctls) is subject to change.

Signed-off-by: Andrea Paterniani <a.paterniani@swapp-eng.it>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:15 -07:00