Note that at this point there is no CONFIG_ZCACHE_DEBUG
option in the Kconfig. So in effect all of the counters
are nop until that option gets re-introduced in:
zcache/debug: Coalesce all debug under CONFIG_ZCACHE_DEBUG
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
[v1: Fixed conflicts due to rebase]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
as if you are debugging this driver you would be using 'debug'
on the command line anyhow - and this would dump the debug
data on the proper loglevel.
While at it also remove the unconditional #define ZCACHE_DEBUG.
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
And now we can move the code ([inc|dec]_zcache_[*]) to their own file
with a header to make them nops or feed in debugfs.
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This way we can have all wrapped with these functions and
can disable/enable this with CONFIG_DEBUG_FS.
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
[v2: Rebase on top of staging/zcache: Fix/improve zcache writeback code, tie to a config option]
[v3: Rebase on top of zcache: Fix compile warnings due to usage of debugfs_create_size_t]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is the first step in moving the debugfs code out of the
main file in-to another file. And also allow the code to run
without CONFIG_DEBUG_FS defined.
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
[v2: Rebase on top staging/zcache: Fix/improve zcache writeback code, tie to a config option]
[v3: Rebase on top of zcache: Fix compile warnings due to usage of debugfs_create_size_t]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are so many, but this allows us to at least have them
right in as bool.
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
[v1: Rebase on ramster->zcache move]
[v2: Rebase on staging/zcache: Fix/improve zcache writeback code, tie to a config option]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Modify the kernel logger to record the UID associated with
the log entries. Always allow the same UID which generated a
log message to read the log message.
Allow anyone in the logs group, or anyone with CAP_SYSLOG, to
read all log entries.
In addition, allow the client to upgrade log formats, so they
can get additional information from the kernel.
Cc: Android Kernel Team <kernel-team@android.com>
Cc: Nick Kralevich <nnk@google.com>
Signed-off-by: Nick Kralevich <nnk@google.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Problem:
There exists a path in ashmem driver that could lead to acquistion
of mm->mmap_sem, ashmem_mutex in reverse order. This could lead
to deadlock in the system.
For Example, assume that mmap is called on a ashmem region
in the context of a thread say T1.
sys_mmap_pgoff (1. acquires mm->mmap_sem)
|
--> mmap_region
|
----> ashmem_mmap (2. acquires asmem_mutex)
Now if there is a context switch after 1 and before 2,
and if another thread T2 (that shares the mm struct) invokes an
ioctl say ASHMEM_GET_NAME, this can lead to the following path
ashmem_ioctl
|
-->get_name (3. acquires ashmem_mutex)
|
---> copy_to_user (4. acquires the mm->mmap_sem)
Note that the copy_to_user could lead to a valid fault if no
physical page is allocated yet for the user address passed.
Now T1 has mmap_sem and is waiting for ashmem_mutex.
and T2 has the ashmem_mutex and is waiting for mmap_sem
Thus leading to deadlock.
Solution:
Do not call copy_to_user or copy_from_user while holding the
ahsmem_mutex. Instead copy this to a local buffer that lives
in the stack while holding this lock. This will maintain data
integrity as well never reverse the lock order.
Testing:
Created a unit test case to reproduce the problem.
Used the same to test this fix on kernel version 3.4.0
Ported the same patch to 3.8
Signed-off-by: Shankar Brahadeeswaran <shankoo77@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull fbdev UAPI disintegration from David Howells:
"You'll be glad to here that the end is nigh for the UAPI patches.
Only the fbdev/framebuffer piece remains now that the SCSI stuff has
gone in.
Here are the UAPI disintegration bits for the fbdev drivers. It
appears that Florian hasn't had time to deal with my patch, but back
in December he did say he didn't mind if I pushed it forward."
Yay. No more uapi movement. And hopefully no more big header file
cleanups coming up either, it just tends to be very painful.
* tag 'disintegrate-fbdev-20121220' of git://git.infradead.org/users/dhowells/linux-headers:
UAPI: (Scripted) Disintegrate include/video
Pull Xen bug-fixes from Konrad Rzeszutek Wilk:
- Update the Xen ACPI memory and CPU hotplug locking mechanism.
- Fix PAT issues wherein various applications would not start
- Fix handling of multiple MSI as AHCI now does it.
- Fix ARM compile failures.
* tag 'stable/for-linus-3.9-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xenbus: fix compile failure on ARM with Xen enabled
xen/pci: We don't do multiple MSI's.
xen/pat: Disable PAT using pat_enabled value.
xen/acpi: xen cpu hotplug minor updates
xen/acpi: xen memory hotplug minor updates
Pull more VFS bits from Al Viro:
"Unfortunately, it looks like xattr series will have to wait until the
next cycle ;-/
This pile contains 9p cleanups and fixes (races in v9fs_fid_add()
etc), fixup for nommu breakage in shmem.c, several cleanups and a bit
more file_inode() work"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
constify path_get/path_put and fs_struct.c stuff
fix nommu breakage in shmem.c
cache the value of file_inode() in struct file
9p: if v9fs_fid_lookup() gets to asking server, it'd better have hashed dentry
9p: make sure ->lookup() adds fid to the right dentry
9p: untangle ->lookup() a bit
9p: double iput() in ->lookup() if d_materialise_unique() fails
9p: v9fs_fid_add() can't fail now
v9fs: get rid of v9fs_dentry
9p: turn fid->dlist into hlist
9p: don't bother with private lock in ->d_fsdata; dentry->d_lock will do just fine
more file_inode() open-coded instances
selinux: opened file can't have NULL or negative ->f_path.dentry
(In the meantime, the hlist traversal macros have changed, so this
required a semantic conflict fixup for the newly hlistified fid->dlist)
Pull btrfs fixup from Chris Mason:
"Geert and James both sent this one in, sorry guys"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
btrfs/raid56: Add missing #include <linux/vmalloc.h>
Pull second set of s390 patches from Martin Schwidefsky:
"The main part of this merge are Heikos uaccess patches. Together with
commit 0988496433 ("mm: do not grow the stack vma just because of an
overrun on preceding vma") the user string access is hopefully fixed
for good.
In addition some bug fixes and two cleanup patches."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/module: fix compile warning
qdio: remove unused parameters
s390/uaccess: fix kernel ds access for page table walk
s390/uaccess: fix strncpy_from_user string length check
input: disable i8042 PC Keyboard controller for s390
s390/dis: Fix invalid array size
s390/uaccess: remove pointless access_ok() checks
s390/uaccess: fix strncpy_from_user/strnlen_user zero maxlen case
s390/uaccess: shorten strncpy_from_user/strnlen_user
s390/dasd: fix unresponsive device after all channel paths were lost
s390/mm: ignore change bit for vmemmap
s390/page table dumper: add support for change-recording override bit
Pull second round of PARISC updates from Helge Deller:
"The most important fix in this branch is the switch of io_setup,
io_getevents and io_submit syscalls to use the available compat
syscalls when running 32bit userspace on 64bit kernel. Other than
that it's mostly removal of compile warnings."
* 'fixes-for-3.9-latest' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: fix redefinition of SET_PERSONALITY
parisc: do not install modules when installing kernel
parisc: fix compile warnings triggered by atomic_sub(sizeof(),v)
parisc: check return value of down_interruptible() in hp_sdc_rtc.c
parisc: avoid unitialized variable warning in pa_memcpy()
parisc: remove unused variable 'compat_val'
parisc: switch to compat_functions of io_setup, io_getevents and io_submit
parisc: select ARCH_WANT_FRAME_POINTERS
