08 Dec, 2018
1 commit
-
commit 77d2a24b6107bd9b3bf2403a65c1428a9da83dd0 upstream.
gcc 8.1.0 complains:
lib/kobject.c:128:3: warning:
'strncpy' output truncated before terminating nul copying as many
bytes from a string as its length [-Wstringop-truncation]
lib/kobject.c: In function 'kobject_get_path':
lib/kobject.c:125:13: note: length computed hereUsing strncpy() is indeed less than perfect since the length of data to
be copied has already been determined with strlen(). Replace strncpy()
with memcpy() to address the warning and optimize the code a little.Signed-off-by: Guenter Roeck
Signed-off-by: Greg Kroah-Hartman
Signed-off-by: Greg Kroah-Hartman
02 May, 2018
1 commit
-
commit 3e14c6abbfb5c94506edda9d8e2c145d79375798 upstream.
This WARNING proved to be noisy. The function still returns an error
and callers should handle it. That's how most of kernel code works.
Downgrade the WARNING to pr_err() and leave WARNINGs for kernel bugs.Signed-off-by: Dmitry Vyukov
Reported-by: syzbot+209c0f67f99fec8eb14b@syzkaller.appspotmail.com
Reported-by: syzbot+7fb6d9525a4528104e05@syzkaller.appspotmail.com
Reported-by: syzbot+2e63711063e2d8f9ea27@syzkaller.appspotmail.com
Reported-by: syzbot+de73361ee4971b6e6f75@syzkaller.appspotmail.com
Cc: stable
Signed-off-by: Greg Kroah-Hartman
23 Mar, 2017
1 commit
-
Make the function available for outside use and fortify it against NULL
kobject.CC: Greg Kroah-Hartman
Reviewed-by: Bart Van Assche
Acked-by: Tejun Heo
Signed-off-by: Jan Kara
Signed-off-by: Jens Axboe
10 Feb, 2016
1 commit
-
Signed-off-by: Gabriel Somlo
Signed-off-by: Greg Kroah-Hartman
07 Nov, 2015
1 commit
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Sometimes kobject_set_name_vargs is called with a format string conaining
no %, or a format string of precisely "%s", where the single vararg
happens to point to .rodata. kvasprintf_const detects these cases for us
and returns a copy of that pointer instead of duplicating the string, thus
saving some run-time memory. Otherwise, it falls back to kvasprintf. We
just need to always deallocate ->name using kfree_const.Unfortunately, the dance we need to do to perform the '/' -> '!'
sanitization makes the resulting code rather ugly.I instrumented kstrdup_const to provide some statistics on the memory
saved, and for me this gave an additional ~14KB after boot (306KB was
already saved; this patch bumped that to 320KB). I have
KMALLOC_SHIFT_LOW==3, and since 80% of the kvasprintf_const hits were
satisfied by an 8-byte allocation, the 14K would roughly be quadrupled
when KMALLOC_SHIFT_LOW==5. Whether these numbers are sufficient to
justify the ugliness I'll leave to others to decide.Signed-off-by: Rasmus Villemoes
Cc: Greg KH
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Oct, 2015
1 commit
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Move EXPORT_SYMBOL() macros in kobject.c from the end of the file
next to the function definitions to which they belong.Signed-off-by: Gabriel Somlo
Signed-off-by: Greg Kroah-Hartman
18 Jul, 2015
1 commit
-
Using __printf attributes helps to detect several format string issues
at compile time (even though -Wformat-security is currently disabled in
Makefile). For example it can detect when formatting a pointer as a
number, like the issue fixed in commit a3fa71c40f18 ("wl18xx: show
rx_frames_per_rates as an array as it really is"), or when the arguments
do not match the format string, c.f. for example commit 5ce1aca81435
("reiserfs: fix __RASSERT format string").To prevent similar bugs in the future, add a __printf attribute to every
function prototype which needs one in include/linux/ and lib/. These
functions were mostly found by using gcc's -Wsuggest-attribute=format
flag.Signed-off-by: Nicolas Iooss
Cc: Greg Kroah-Hartman
Cc: Felipe Balbi
Cc: Joel Becker
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Jul, 2015
1 commit
-
Pull btrfs updates from Chris Mason:
"Outside of our usual batch of fixes, this integrates the subvolume
quota updates that Qu Wenruo from Fujitsu has been working on for a
few releases now. He gets an extra gold star for making btrfs smaller
this time, and fixing a number of quota corners in the process.Dave Sterba tested and integrated Anand Jain's sysfs improvements.
Outside of exporting a symbol (ack'd by Greg) these are all internal
to btrfs and it's mostly cleanups and fixes. Anand also attached some
of our sysfs objects to our internal device management structs instead
of an object off the super block. It will make device management
easier overall and it's a better fit for how the sysfs files are used.
None of the existing sysfs files are moved around.Thanks for all the fixes everyone"
* 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (87 commits)
btrfs: delayed-ref: double free in btrfs_add_delayed_tree_ref()
Btrfs: Check if kobject is initialized before put
lib: export symbol kobject_move()
Btrfs: sysfs: add support to show replacing target in the sysfs
Btrfs: free the stale device
Btrfs: use received_uuid of parent during send
Btrfs: fix use-after-free in btrfs_replay_log
btrfs: wait for delayed iputs on no space
btrfs: qgroup: Make snapshot accounting work with new extent-oriented qgroup.
btrfs: qgroup: Add the ability to skip given qgroup for old/new_roots.
btrfs: ulist: Add ulist_del() function.
btrfs: qgroup: Cleanup the old ref_node-oriented mechanism.
btrfs: qgroup: Switch self test to extent-oriented qgroup mechanism.
btrfs: qgroup: Switch to new extent-oriented qgroup mechanism.
btrfs: qgroup: Switch rescan to new mechanism.
btrfs: qgroup: Add new qgroup calculation function btrfs_qgroup_account_extents().
btrfs: backref: Add special time_seq == (u64)-1 case for btrfs_find_all_roots().
btrfs: qgroup: Add new function to record old_roots.
btrfs: qgroup: Record possible quota-related extent for qgroup.
btrfs: qgroup: Add function qgroup_update_counters().
...
26 Jun, 2015
1 commit
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There's probably not many slashes in the name, but starting over when
we see one feels wrong.Signed-off-by: Rasmus Villemoes
Cc: Greg Kroah-Hartman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
19 Jun, 2015
1 commit
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drivers/cpufreq/cpufreq.c is already using this function. And now btrfs
needs it as well. Export symbol kobject_move().Signed-off-by: Anand Jain
Acked-by: Greg Kroah-Hartman
Signed-off-by: David Sterba
25 Mar, 2015
1 commit
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call kobject_get() to kojbect that is not initalized or released will only
leave following like call trace to us:-----------[ cut here ]------------
[ 54.545816] WARNING: CPU: 0 PID: 213 at include/linux/kref.h:47
kobject_get+0x41/0x50()
[ 54.642595] Modules linked in: i2c_i801(+) mfd_core shpchp(+)
acpi_cpufreq(+) edac_core ioatdma(+) xfs libcrc32c ast syscopyarea ixgbe
sysfillrect sysimgblt sr_mod sd_mod drm_kms_helper igb mdio cdrom e1000e ahci
dca ttm libahci uas drm i2c_algo_bit ptp megaraid_sas libata usb_storage
i2c_core pps_core dm_mirror dm_region_hash dm_log dm_mod
[ 55.007264] CPU: 0 PID: 213 Comm: kworker/0:2 Not tainted
3.18.5
[ 55.099970] Hardware name: Oracle Corporation SUN FIRE X4170 M2 SERVER
/ASSY,MOTHERBOARD,X4170, BIOS 08120104 05/08/2012
[ 55.239736] Workqueue: kacpi_notify acpi_os_execute_deferred
[ 55.308598] 0000000000000000 00000000bd730b61 ffff88046742baf8
ffffffff816b7edb
[ 55.398305] 0000000000000000 0000000000000000 ffff88046742bb38
ffffffff81078ae1
[ 55.488040] ffff88046742bbd8 ffff8806706b3000 0000000000000292
0000000000000000
[ 55.577776] Call Trace:
[ 55.608228] [] dump_stack+0x46/0x58
[ 55.670895] [] warn_slowpath_common+0x81/0xa0
[ 55.743952] [] warn_slowpath_null+0x1a/0x20
[ 55.814929] [] kobject_get+0x41/0x50
[ 55.878654] [] cpufreq_cpu_get+0x75/0xc0
[ 55.946528] [] cpufreq_update_policy+0x2e/0x1f0The above issue was casued by a race condition, if there is a WARN in
kobject_get() of the kobject is not initialized, that would save us much
time to debug it.Signed-off-by: Ethan Zhao
Signed-off-by: Greg Kroah-Hartman
08 Nov, 2014
1 commit
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We will hit NULL pointer dereference if we call
platform_device_register_simple or platform_device_add at very early
stage. I have observed following crash when called platform_device_add
from "init_irq" hook of machine_desc. This patch fixes this issue and
let system handle this case gracefully instead of kernel panic.[0.000000] Unable to handle kernel NULL pointer dereference at
virtual address 0000000c
[0.000000] pgd = c0004000
[0.000000] [0000000c] *pgd=00000000
[0.000000] Internal error: Oops: 5 [#1] PREEMPT ARM
[0.000000] Modules linked in:
[0.000000] CPU: 0 PID: 0 Comm: swapper Tainted: G W 3.17.0-rc6-00198-ga1603f1-dirty #319
[0.000000] task: c05b23f0 ti: c05a8000 task.ti: c05a8000
[0.000000] PC is at kobject_namespace+0x18/0x58
[0.000000] LR is at kobject_add_internal+0x90/0x2ec
[snip]
[0.000000] [] (kobject_namespace) from [] (kobject_add_internal+0x90/0x2ec)
[0.000000] [] (kobject_add_internal) from [] (kobject_add+0x4c/0x98)
[0.000000] [] (kobject_add) from [] (device_add+0xe8/0x51c)
[0.000000] [] (device_add) from [] (platform_device_add+0xb4/0x214)
[0.000000] [] (platform_device_add) from [] (platform_device_register_full+0xb8/0xdc)
[0.000000] [] (platform_device_register_full) from [] (exynos_init_irq+0x90/0x9c)
[0.000000] [] (exynos_init_irq) from [] (init_IRQ+0x2c/0x78)
[0.000000] [] (init_IRQ) from [] (start_kernel+0x22c/0x378)
[0.000000] [] (start_kernel) from [] (0x40008070)
[0.000000] Code: e590000c e3500000 0a00000e e5903014 (e593300c)Signed-off-by: Pankaj Dubey
Signed-off-by: Greg Kroah-Hartman
08 Feb, 2014
1 commit
-
Currently, kobject is invoking kernfs_enable_ns() directly. This is
fine now as sysfs and kernfs are enabled and disabled together. If
sysfs is disabled, kernfs_enable_ns() is switched to dummy
implementation too and everything is fine; however, kernfs will soon
have its own config option CONFIG_KERNFS and !SYSFS && KERNFS will be
possible, which can make kobject call into non-dummy
kernfs_enable_ns() with NULL kernfs_node pointers leading to an oops.Introduce sysfs_enable_ns() which is a wrapper around
kernfs_enable_ns() so that it can be made a noop depending only on
CONFIG_SYSFS regardless of the planned CONFIG_KERNFS.Signed-off-by: Tejun Heo
Reported-by: Fengguang Wu
Signed-off-by: Greg Kroah-Hartman
31 Jan, 2014
1 commit
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Pull btrfs updates from Chris Mason:
"This is a pretty big pull, and most of these changes have been
floating in btrfs-next for a long time. Filipe's properties work is a
cool building block for inheriting attributes like compression down on
a per inode basis.Jeff Mahoney kicked in code to export filesystem info into sysfs.
Otherwise, lots of performance improvements, cleanups and bug fixes.
Looks like there are still a few other small pending incrementals, but
I wanted to get the bulk of this in first"* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (149 commits)
Btrfs: fix spin_unlock in check_ref_cleanup
Btrfs: setup inode location during btrfs_init_inode_locked
Btrfs: don't use ram_bytes for uncompressed inline items
Btrfs: fix btrfs_search_slot_for_read backwards iteration
Btrfs: do not export ulist functions
Btrfs: rework ulist with list+rb_tree
Btrfs: fix memory leaks on walking backrefs failure
Btrfs: fix send file hole detection leading to data corruption
Btrfs: add a reschedule point in btrfs_find_all_roots()
Btrfs: make send's file extent item search more efficient
Btrfs: fix to catch all errors when resolving indirect ref
Btrfs: fix protection between walking backrefs and root deletion
btrfs: fix warning while merging two adjacent extents
Btrfs: fix infinite path build loops in incremental send
btrfs: undo sysfs when open_ctree() fails
Btrfs: fix snprintf usage by send's gen_unique_name
btrfs: fix defrag 32-bit integer overflow
btrfs: sysfs: list the NO_HOLES feature
btrfs: sysfs: don't show reserved incompat feature
btrfs: call permission checks earlier in ioctls and return EPERM
...
29 Jan, 2014
1 commit
-
struct kobj_attribute implements the baseline attribute functionality
that can be used all over the place. We should export the ops associated
with it.Signed-off-by: Jeff Mahoney
Signed-off-by: Greg Kroah-Hartman
Signed-off-by: Josef Bacik
Signed-off-by: Chris Mason
09 Jan, 2014
1 commit
-
Signed-off-by: Bart Van Assche
Signed-off-by: Greg Kroah-Hartman
05 Jan, 2014
1 commit
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This reverts commit eee031649707db3c9920d9498f8d03819b74fc23.
Jeff writes:
I have no objections to reverting it. There were concerns from
Al Viro that it'd be tough to get right by callers and I had
assumed it got dropped after that. I had planned on using it in
my btrfs sysfs exports patchset but came up with a better way.Cc: Jeff Mahoney
Cc: Al Viro
Signed-off-by: Greg Kroah-Hartman
12 Dec, 2013
1 commit
-
kernfs has just been separated out from sysfs and we're already in
full conflict mode. Nothing can make the situation any worse. Let's
take the chance to name things properly.This patch performs the following renames.
* s/sysfs_elem_dir/kernfs_elem_dir/
* s/sysfs_elem_symlink/kernfs_elem_symlink/
* s/sysfs_elem_attr/kernfs_elem_file/
* s/sysfs_dirent/kernfs_node/
* s/sd/kn/ in kernfs proper
* s/parent_sd/parent/
* s/target_sd/target/
* s/dir_sd/parent/
* s/to_sysfs_dirent()/rb_to_kn()/
* misc renames of local vars when they conflict with the aboveBecause md, mic and gpio dig into sysfs details, this patch ends up
modifying them. All are sysfs_dirent renames and trivial. While we
can avoid these by introducing a dummy wrapping struct sysfs_dirent
around kernfs_node, given the limited usage outside kernfs and sysfs
proper, I don't think such workaround is called for.This patch is strictly rename only and doesn't introduce any
functional difference.- mic / gpio renames were missing. Spotted by kbuild test robot.
Signed-off-by: Tejun Heo
Cc: Neil Brown
Cc: Linus Walleij
Cc: Ashutosh Dixit
Cc: kbuild test robot
Signed-off-by: Greg Kroah-Hartman
09 Dec, 2013
1 commit
-
If the call to kvasprintf fails then the old name of the object will be leaked,
this patch fixes the bug by restoring the old name before returning ENOMEM.Signed-off-by: Maurizio Lombardi
Signed-off-by: Greg Kroah-Hartman
08 Dec, 2013
2 commits
-
There's no "unlink from sysfs" interface for ksets, so I think callers of
kset_unregister() expect the kset to be removed from sysfs immediately,
without waiting for the last reference to be released.This patch makes the sysfs removal happen immediately, so the caller may
create a new kset with the same name as soon as kset_unregister() returns.
Without this, every caller has to call "kobject_del(&kset->kobj)" first
unless it knows it will never create a new kset with the same name.This sometimes shows up on module unload and reload, where the reload fails
because it tries to create a kobject with the same name as one from the
original load that still exists. CONFIG_DEBUG_KOBJECT_RELEASE=y makes this
problem easier to hit.Signed-off-by: Bjorn Helgaas
Signed-off-by: Greg Kroah-Hartman -
When CONFIG_DEBUG_KOBJECT_RELEASE=y, delay kobject release functions for a
random time between 1 and 8 seconds, which effectively changes the order in
which they're called.Signed-off-by: Bjorn Helgaas
Signed-off-by: Greg Kroah-Hartman
30 Nov, 2013
1 commit
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Introduce kernfs interface to manipulate a directory which takes and
returns sysfs_dirents.create_dir() is renamed to kernfs_create_dir_ns() and its argumantes
and return value are updated. create_dir() usages are replaced with
kernfs_create_dir_ns() and sysfs_create_subdir() usages are replaced
with kernfs_create_dir(). Dup warnings are handled explicitly by
sysfs users of the kernfs interface.sysfs_enable_ns() is renamed to kernfs_enable_ns().
This patch doesn't introduce any behavior changes.
v2: Dummy implementation for !CONFIG_SYSFS updated to return -ENOSYS.
v3: kernfs_enable_ns() added.
v4: Refreshed on top of "sysfs: drop kobj_ns_type handling, take #2"
so that this patch removes sysfs_enable_ns().Signed-off-by: Tejun Heo
Signed-off-by: Greg Kroah-Hartman
28 Nov, 2013
1 commit
-
The way namespace tags are implemented in sysfs is more complicated
than necessary. As each tag is a pointer value and required to be
non-NULL under a namespace enabled parent, there's no need to record
separately what type each tag is. If multiple namespace types are
needed, which currently aren't, we can simply compare the tag to a set
of allowed tags in the superblock assuming that the tags, being
pointers, won't have the same value across multiple types.This patch rips out kobj_ns_type handling from sysfs. sysfs now has
an enable switch to turn on namespace under a node. If enabled, all
children are required to have non-NULL namespace tags and filtered
against the super_block's tag.kobject namespace determination is now performed in
lib/kobject.c::create_dir() making sysfs_read_ns_type() unnecessary.
The sanity checks are also moved. create_dir() is restructured to
ease such addition. This removes most kobject namespace knowledge
from sysfs proper which will enable proper separation and layering of
sysfs.This is the second try. The first one was cb26a311578e ("sysfs: drop
kobj_ns_type handling") which tried to automatically enable namespace
if there are children with non-NULL namespace tags; however, it was
broken for symlinks as they should inherit the target's tag iff
namespace is enabled in the parent. This led to namespace filtering
enabled incorrectly for wireless net class devices through phy80211
symlinks and thus network configuration failure. a1212d278c05
("Revert "sysfs: drop kobj_ns_type handling"") reverted the commit.This shouldn't introduce any behavior changes, for real.
v2: Dummy implementation of sysfs_enable_ns() for !CONFIG_SYSFS was
missing and caused build failure. Reported by kbuild test robot.Signed-off-by: Tejun Heo
Reported-by: Linus Torvalds
Cc: Eric W. Biederman
Cc: Kay Sievers
Cc: Greg Kroah-Hartman
Cc: kbuild test robot
Signed-off-by: Greg Kroah-Hartman
07 Nov, 2013
1 commit
-
This reverts commit cb26a311578e67769e92a39a0a63476533cb7e12.
It mysteriously causes NetworkManager to not find the wireless device
for me. As far as I can tell, Tejun *meant* for this commit to not make
any semantic changes, but there clearly are some. So revert it, taking
into account some of the calling convention changes that happened in
this area in subsequent commits.Cc: Tejun Heo
Cc: Greg Kroah-Hartman
Signed-off-by: Linus Torvalds
12 Oct, 2013
1 commit
-
Useful for locating buggy drivers on kernel oops.
It may add dozens of new lines to boot dmesg. DEBUG_KOBJECT_RELEASE is
hopefully only enabled in debug kernels (like maybe the Fedora rawhide
one, or at developers), so being a bit more verbose is likely ok.Signed-off-by: Fengguang Wu
Acked-by: Russell King
Signed-off-by: Greg Kroah-Hartman
04 Oct, 2013
1 commit
-
sysfs currently has a rather weird behavior regarding removals. A
directory removal would delete all files directly under it but
wouldn't recurse into subdirectories, which, while a bit inconsistent,
seems to make sense at the first glance as each directory is
supposedly associated with a kobject and each kobject can take care of
the directory deletion; however, this doesn't really hold as we have
groups which can be directories without a kobject associated with it
and require explicit deletions.We're in the process of separating out sysfs from kboject / driver
core and want a consistent behavior. A removal should delete either
only the specified node or everything under it. I think it is helpful
to support recursive atomic removal and later patches will implement
it.Such change means that a sysfs_dirent associated with kobject may be
deleted before the kobject itself is removed if one of its ancestor
gets removed before it. As sysfs_remove_dir() puts the base ref, we
may end up with dangling pointer on descendants. This can be solved
by holding an extra reference on the sd from kobject.Acquire an extra reference on the associated sysfs_dirent on directory
creation and put it after removal.Signed-off-by: Tejun Heo
Signed-off-by: Greg Kroah-Hartman
30 Sep, 2013
1 commit
-
We want the driver core and sysfs fixes in here to make merges and
development easier.Signed-off-by: Greg Kroah-Hartman
28 Sep, 2013
1 commit
-
In kobj_ns_current_may_mount the default should be to allow the mount.
The test is only for a single kobj_ns_type at a time, and unless there
is a reason to prevent it the mounting sysfs should be allowed.
Subsystems that are not registered can't have are not involved so can't
have a reason to prevent mounting sysfs.This is a bug-fix to commit 7dc5dbc879bd ("sysfs: Restrict mounting
sysfs") that came in via the userns tree during the 3.12 merge window.Reported-and-tested-by: James Hogan
Signed-off-by: "Eric W. Biederman"
Signed-off-by: Linus Torvalds
27 Sep, 2013
3 commits
-
A common way to handle kobject lifetimes in embedded in objects with
different lifetime rules is to pair the kobject with a struct completion.This introduces a kobj_completion structure that can be used in place
of the pairing, along with several convenience functions for
initialization, release, and put-and-wait.Signed-off-by: Jeff Mahoney
Signed-off-by: Greg Kroah-Hartman -
The way namespace tags are implemented in sysfs is more complicated
than necessary. As each tag is a pointer value and required to be
non-NULL under a namespace enabled parent, there's no need to record
separately what type each tag is or where namespace is enabled.If multiple namespace types are needed, which currently aren't, we can
simply compare the tag to a set of allowed tags in the superblock
assuming that the tags, being pointers, won't have the same value
across multiple types. Also, whether to filter by namespace tag or
not can be trivially determined by whether the node has any tagged
children or not.This patch rips out kobj_ns_type handling from sysfs. sysfs no longer
cares whether specific type of namespace is enabled or not. If a
sysfs_dirent has a non-NULL tag, the parent is marked as needing
namespace filtering and the value is tested against the allowed set of
tags for the superblock (currently only one but increasing this number
isn't difficult) and the sysfs_dirent is ignored if it doesn't match.This removes most kobject namespace knowledge from sysfs proper which
will enable proper separation and layering of sysfs. The namespace
sanity checks in fs/sysfs/dir.c are replaced by the new sanity check
in kobject_namespace(). As this is the only place ktype->namespace()
is called for sysfs, this doesn't weaken the sanity check
significantly. I omitted converting the sanity check in
sysfs_do_create_link_sd(). While the check can be shifted to upper
layer, mistakes there are well contained and should be easily visible
anyway.Signed-off-by: Tejun Heo
Cc: Eric W. Biederman
Cc: Kay Sievers
Signed-off-by: Greg Kroah-Hartman -
For some unrecognizable reason, namespace information is communicated
to sysfs through ktype->namespace() callback when there's *nothing*
which needs the use of a callback. The whole sequence of operations
is completely synchronous and sysfs operations simply end up calling
back into the layer which just invoked it in order to find out the
namespace information, which is completely backwards, obfuscates
what's going on and unnecessarily tangles two separate layers.This patch doesn't remove ktype->namespace() but shifts its handling
to kobject layer. We probably want to get rid of the callback in the
long term.This patch adds an explicit param to sysfs_{create|rename|move}_dir()
and renames them to sysfs_{create|rename|move}_dir_ns(), respectively.
ktype->namespace() invocations are moved to the calling sites of the
above functions. A new helper kboject_namespace() is introduced which
directly tests kobj_ns_type_operations->type which should give the
same result as testing sysfs_fs_type(parent_sd) and returns @kobj's
namespace tag as necessary. kobject_namespace() is extern as it will
be used from another file in the following patches.This patch should be an equivalent conversion without any functional
difference.Signed-off-by: Tejun Heo
Cc: Eric W. Biederman
Cc: Kay Sievers
Signed-off-by: Greg Kroah-Hartman
08 Sep, 2013
1 commit
-
Pull namespace changes from Eric Biederman:
"This is an assorted mishmash of small cleanups, enhancements and bug
fixes.The major theme is user namespace mount restrictions. nsown_capable
is killed as it encourages not thinking about details that need to be
considered. A very hard to hit pid namespace exiting bug was finally
tracked and fixed. A couple of cleanups to the basic namespace
infrastructure.Finally there is an enhancement that makes per user namespace
capabilities usable as capabilities, and an enhancement that allows
the per userns root to nice other processes in the user namespace"* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
userns: Kill nsown_capable it makes the wrong thing easy
capabilities: allow nice if we are privileged
pidns: Don't have unshare(CLONE_NEWPID) imply CLONE_THREAD
userns: Allow PR_CAPBSET_DROP in a user namespace.
namespaces: Simplify copy_namespaces so it is clear what is going on.
pidns: Fix hang in zap_pid_ns_processes by sending a potentially extra wakeup
sysfs: Restrict mounting sysfs
userns: Better restrictions on when proc and sysfs can be mounted
vfs: Don't copy mount bind mounts of /proc//ns/mnt between namespaces
kernel/nsproxy.c: Improving a snippet of code.
proc: Restrict mounting the proc filesystem
vfs: Lock in place mounts from more privileged users
29 Aug, 2013
1 commit
-
Don't allow mounting sysfs unless the caller has CAP_SYS_ADMIN rights
over the net namespace. The principle here is if you create or have
capabilities over it you can mount it, otherwise you get to live with
what other people have mounted.Instead of testing this with a straight forward ns_capable call,
perform this check the long and torturous way with kobject helpers,
this keeps direct knowledge of namespaces out of sysfs, and preserves
the existing sysfs abstractions.Acked-by: Greg Kroah-Hartman
Signed-off-by: "Eric W. Biederman"
26 Jul, 2013
1 commit
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Implement debugging for kobject release functions. kobjects are
reference counted, so the drop of the last reference to them is not
predictable. However, the common case is for the last reference to be
the kobject's removal from a subsystem, which results in the release
function being immediately called.This can hide subtle bugs, which can occur when another thread holds a
reference to the kobject at the same time that a kobject is removed.
This results in the release method being delayed.In order to make these kinds of problems more visible, the following
patch implements a delayed release; this has the effect that the
release function will be out of order with respect to the removal of
the kobject in the same manner that it would be if a reference was
being held.This provides us with an easy way to allow driver writers to debug
their drivers and fix otherwise hidden problems.Signed-off-by: Russell King
Signed-off-by: Greg Kroah-Hartman
08 Jun, 2013
1 commit
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Unlike kobject_set_name(), the kset_create_and_add() interface does not
provide a way to use format strings, so make sure that the interface
cannot be abused accidentally. It looks like all current callers use
static strings, so there's no existing flaw.Signed-off-by: Kees Cook
Signed-off-by: Greg Kroah-Hartman
08 May, 2013
1 commit
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- make warning smp-safe
- result of atomic _unless_zero functions should be checked by caller
to avoid use-after-free error
- trivial whitespace fix.Link: https://lkml.org/lkml/2013/4/12/391
Tested: compile x86, boot machine and run xfstests
Signed-off-by: Anatol Pomozov
[ Removed line-break, changed to use WARN_ON_ONCE() - Linus ]
Signed-off-by: Linus Torvalds
14 Apr, 2013
1 commit
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Anatol Pomozov identified a race condition that hits module unloading
and re-loading. To quote Anatol:"This is a race codition that exists between kset_find_obj() and
kobject_put(). kset_find_obj() might return kobject that has refcount
equal to 0 if this kobject is freeing by kobject_put() in other
thread.Here is timeline for the crash in case if kset_find_obj() searches for
an object tht nobody holds and other thread is doing kobject_put() on
the same kobject:THREAD A (calls kset_find_obj()) THREAD B (calls kobject_put())
splin_lock()
atomic_dec_return(kobj->kref), counter gets zero here
... starts kobject cleanup ....
spin_lock() // WAIT thread A in kobj_kset_leave()
iterate over kset->list
atomic_inc(kobj->kref) (counter becomes 1)
spin_unlock()
spin_lock() // taken
// it does not know that thread A increased counter so it
remove obj from list
spin_unlock()
vfree(module) // frees module object with containing kobj// kobj points to freed memory area!!
kobject_put(kobj) // OOPS!!!!The race above happens because module.c tries to use kset_find_obj()
when somebody unloads module. The module.c code was introduced in
commit 6494a93d55fa"Anatol supplied a patch specific for module.c that worked around the
problem by simply not using kset_find_obj() at all, but rather than make
a local band-aid, this just fixes kset_find_obj() to be thread-safe
using the proper model of refusing the get a new reference if the
refcount has already dropped to zero.See examples of this proper refcount handling not only in the kref
documentation, but in various other equivalent uses of this pattern by
grepping for atomic_inc_not_zero().[ Side note: the module race does indicate that module loading and
unloading is not properly serialized wrt sysfs information using the
module mutex. That may require further thought, but this is the
correct fix at the kobject layer regardless. ]Reported-analyzed-and-tested-by: Anatol Pomozov
Cc: Greg Kroah-Hartman
Cc: Al Viro
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds
08 May, 2012
1 commit
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Signed-off-by: Zhi Yong Wu
Signed-off-by: Greg Kroah-Hartman
03 May, 2012
1 commit
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This was done to resolve a merge issue with the init/main.c file.
Reported-by: Stephen Rothwell
Signed-off-by: Greg Kroah-Hartman
24 Apr, 2012
1 commit
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create_dir is a static function used only in kobject_add_internal.
There's no need to do check here, for kobject_add_internal will
reject kobject with invalid name.Signed-off-by: Yan Hong
Signed-off-by: Greg Kroah-Hartman
