Public bug reported:
SRU Justification: This patch has been accepted into the upstream 2.6.27.4
stable kernel.
It should be pulled into the Ubuntu kernel as well.
TEST CASE: TBD
commit a2d18f62f58e8b5128c4ac7173ac15a8fa559b9c
Author: David Brownell <[EMAIL PROTECTED]>
Date: Mon Oct 20 16:50:10 2008 +0000
gpiolib: fix oops in gpio_get_value_cansleep()
commit 978ccaa8ea5d8c7bf6b676209f2fc126eae6355b upstream
We can get the following oops from gpio_get_value_cansleep() when a GPIO
controller doesn't provide a get() callback:
Unable to handle kernel paging request for instruction fetch
Faulting instruction address: 0x00000000
Oops: Kernel access of bad area, sig: 11 [#1]
[...]
NIP [00000000] 0x0
LR [c0182fb0] gpio_get_value_cansleep+0x40/0x50
Call Trace:
[c7b79e80] [c0183f28] gpio_value_show+0x5c/0x94
[c7b79ea0] [c01a584c] dev_attr_show+0x30/0x7c
[c7b79eb0] [c00d6b48] fill_read_buffer+0x68/0xe0
[c7b79ed0] [c00d6c54] sysfs_read_file+0x94/0xbc
[c7b79ef0] [c008f24c] vfs_read+0xb4/0x16c
[c7b79f10] [c008f580] sys_read+0x4c/0x90
[c7b79f40] [c0013a14] ret_from_syscall+0x0/0x38
It's OK to request the value of *any* GPIO; most GPIOs are bidirectional,
so configuring them as outputs just enables an output driver and doesn't
disable the input logic.
So the problem is that gpio_get_value_cansleep() isn't making the same
sanity check that gpio_get_value() does: making sure this GPIO isn't one
of the atypical "no input logic" cases.
Reported-by: Anton Vorontsov <[EMAIL PROTECTED]>
Signed-off-by: David Brownell <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
Signed-off-by: Greg Kroah-Hartman <[EMAIL PROTECTED]>
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
--
gpiolib: fix oops in gpio_get_value_cansleep()
https://bugs.launchpad.net/bugs/294018
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
--
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
