09 Jan, 2020
1 commit
-
[ Upstream commit 0b8d616fb5a8ffa307b1d3af37f55c15dae14f28 ]
When assiging and testing taskstats in taskstats_exit() there's a race
when setting up and reading sig->stats when a thread-group with more
than one thread exits:write to 0xffff8881157bbe10 of 8 bytes by task 7951 on cpu 0:
taskstats_tgid_alloc kernel/taskstats.c:567 [inline]
taskstats_exit+0x6b7/0x717 kernel/taskstats.c:596
do_exit+0x2c2/0x18e0 kernel/exit.c:864
do_group_exit+0xb4/0x1c0 kernel/exit.c:983
get_signal+0x2a2/0x1320 kernel/signal.c:2734
do_signal+0x3b/0xc00 arch/x86/kernel/signal.c:815
exit_to_usermode_loop+0x250/0x2c0 arch/x86/entry/common.c:159
prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
do_syscall_64+0x2d7/0x2f0 arch/x86/entry/common.c:299
entry_SYSCALL_64_after_hwframe+0x44/0xa9read to 0xffff8881157bbe10 of 8 bytes by task 7949 on cpu 1:
taskstats_tgid_alloc kernel/taskstats.c:559 [inline]
taskstats_exit+0xb2/0x717 kernel/taskstats.c:596
do_exit+0x2c2/0x18e0 kernel/exit.c:864
do_group_exit+0xb4/0x1c0 kernel/exit.c:983
__do_sys_exit_group kernel/exit.c:994 [inline]
__se_sys_exit_group kernel/exit.c:992 [inline]
__x64_sys_exit_group+0x2e/0x30 kernel/exit.c:992
do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x44/0xa9Fix this by using smp_load_acquire() and smp_store_release().
Reported-by: syzbot+c5d03165a1bd1dead0c1@syzkaller.appspotmail.com
Fixes: 34ec12349c8a ("taskstats: cleanup ->signal->stats allocation")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Brauner
Acked-by: Marco Elver
Reviewed-by: Will Deacon
Reviewed-by: Andrea Parri
Reviewed-by: Dmitry Vyukov
Link: https://lore.kernel.org/r/20191009114809.8643-1-christian.brauner@ubuntu.com
Signed-off-by: Sasha Levin
31 May, 2019
1 commit
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Based on 3 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more detailsthis program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [kishon] [vijay] [abraham]
[i] [kishon]@[ti] [com] this program is distributed in the hope that
it will be useful but without any warranty without even the implied
warranty of merchantability or fitness for a particular purpose see
the gnu general public license for more detailsthis program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [graeme] [gregory]
[gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
[kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
[hk] [hemahk]@[ti] [com] this program is distributed in the hope
that it will be useful but without any warranty without even the
implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more detailsextracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 1105 file(s).
Signed-off-by: Thomas Gleixner
Reviewed-by: Allison Randal
Reviewed-by: Richard Fontana
Reviewed-by: Kate Stewart
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman
28 Apr, 2019
3 commits
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Add options to strictly validate messages and dump messages,
sometimes perhaps validating dump messages non-strictly may
be required, so add an option for that as well.Since none of this can really be applied to existing commands,
set the options everwhere using the following spatch:@@
identifier ops;
expression X;
@@
struct genl_ops ops[] = {
...,
{
.cmd = X,
+ .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
...
},
...
};For new commands one should just not copy the .validate 'opt-out'
flags and thus get strict validation.Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller -
We currently have two levels of strict validation:
1) liberal (default)
- undefined (type >= max) & NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
- garbage at end of message accepted
2) strict (opt-in)
- NLA_UNSPEC attributes accepted
- attribute length >= expected acceptedSplit out parsing strictness into four different options:
* TRAILING - check that there's no trailing data after parsing
attributes (in message or nested)
* MAXTYPE - reject attrs > max known type
* UNSPEC - reject attributes with NLA_UNSPEC policy entries
* STRICT_ATTRS - strictly validate attribute sizeThe default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.We end up with the following renames:
* nla_parse -> nla_parse_deprecated
* nla_parse_strict -> nla_parse_deprecated_strict
* nlmsg_parse -> nlmsg_parse_deprecated
* nlmsg_parse_strict -> nlmsg_parse_deprecated_strict
* nla_parse_nested -> nla_parse_nested_deprecated
* nla_validate_nested -> nla_validate_nested_deprecatedUsing spatch, of course:
@@
expression TB, MAX, HEAD, LEN, POL, EXT;
@@
-nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
+nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)@@
expression TB, MAX, NLA, POL, EXT;
@@
-nla_parse_nested(TB, MAX, NLA, POL, EXT)
+nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)@@
expression START, MAX, POL, EXT;
@@
-nla_validate_nested(START, MAX, POL, EXT)
+nla_validate_nested_deprecated(START, MAX, POL, EXT)@@
expression NLH, HDRLEN, MAX, POL, EXT;
@@
-nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
+nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.In effect then, this adds fully strict validation for any new command.
Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller -
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
netlink based interfaces (including recently added ones) are still not
setting it in kernel generated messages. Without the flag, message parsers
not aware of attribute semantics (e.g. wireshark dissector or libmnl's
mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
the structure of their contents.Unfortunately we cannot just add the flag everywhere as there may be
userspace applications which check nlattr::nla_type directly rather than
through a helper masking out the flags. Therefore the patch renames
nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
are rewritten to use nla_nest_start().Except for changes in include/net/netlink.h, the patch was generated using
this semantic patch:@@ expression E1, E2; @@
-nla_nest_start(E1, E2)
+nla_nest_start_noflag(E1, E2)@@ expression E1, E2; @@
-nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
+nla_nest_start(E1, E2)Signed-off-by: Michal Kubecek
Acked-by: Jiri Pirko
Acked-by: David Ahern
Signed-off-by: David S. Miller
22 Mar, 2019
1 commit
-
Since maxattr is common, the policy can't really differ sanely,
so make it common as well.The only user that did in fact manage to make a non-common policy
is taskstats, which has to be really careful about it (since it's
still using a common maxattr!). This is no longer supported, but
we can fake it using pre_doit.This reduces the size of e.g. nl80211.o (which has lots of commands):
text data bss dec hex filename
398745 14323 2240 415308 6564c net/wireless/nl80211.o (before)
397913 14331 2240 414484 65314 net/wireless/nl80211.o (after)
--------------------------------
-832 +8 0 -824Which is obviously just 8 bytes for each command, and an added 8
bytes for the new policy pointer. I'm not sure why the ops list is
counted as .text though.Most of the code transformations were done using the following spatch:
@ops@
identifier OPS;
expression POLICY;
@@
struct genl_ops OPS[] = {
...,
{
- .policy = POLICY,
},
...
};@@
identifier ops.OPS;
expression ops.POLICY;
identifier fam;
expression M;
@@
struct genl_family fam = {
.ops = OPS,
.maxattr = M,
+ .policy = POLICY,
...
};This also gets rid of devlink_nl_cmd_region_read_dumpit() accessing
the cb->data as ops, which we want to change in a later genl patch.Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller
07 Feb, 2018
1 commit
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There are several functions that do find_task_by_vpid() followed by
get_task_struct(). We can use a helper function instead.Link: http://lkml.kernel.org/r/1509602027-11337-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport
Acked-by: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 May, 2017
1 commit
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The elapsed time, user CPU time and system CPU time for the thread group
status request are presently left at zero. Fill these in.[akpm@linux-foundation.org: run ktime_get_ns() a single time]
[akpm@linux-foundation.org: include linux/sched/cputime.h for task_cputime()]
Link: http://lkml.kernel.org/r/1488508424-12322-1-git-send-email-xiao.zhang@windriver.com
Signed-off-by: Zhang Xiao
Cc: Balbir Singh
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Nov, 2016
1 commit
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Several cases of bug fixes in 'net' overlapping other changes in
'net-next-.Signed-off-by: David S. Miller
04 Nov, 2016
1 commit
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cgroupstats_cmd_get_policy is [CGROUPSTATS_CMD_ATTR_MAX+1],
taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1],
but their family.maxattr is TASKSTATS_CMD_ATTR_MAX.
CGROUPSTATS_CMD_ATTR_MAX is less than TASKSTATS_CMD_ATTR_MAX,
so we could end up accessing out-of-bound.Change cgroupstats_cmd_get_policy to TASKSTATS_CMD_ATTR_MAX+1,
this is safe because the rest are initialized to 0's.Reported-by: Andrey Konovalov
Tested-by: Andrey Konovalov
Signed-off-by: Cong Wang
Signed-off-by: David S. Miller
28 Oct, 2016
3 commits
-
Now genl_register_family() is the only thing (other than the
users themselves, perhaps, but I didn't find any doing that)
writing to the family struct.In all families that I found, genl_register_family() is only
called from __init functions (some indirectly, in which case
I've add __init annotations to clarifly things), so all can
actually be marked __ro_after_init.This protects the data structure from accidental corruption.
Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller -
Instead of providing macros/inline functions to initialize
the families, make all users initialize them statically and
get rid of the macros.This reduces the kernel code size by about 1.6k on x86-64
(with allyesconfig).Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller -
Static family IDs have never really been used, the only
use case was the workaround I introduced for those users
that assumed their family ID was also their multicast
group ID.Additionally, because static family IDs would never be
reserved by the generic netlink code, using a relatively
low ID would only work for built-in families that can be
registered immediately after generic netlink is started,
which is basically only the control family (apart from
the workaround code, which I also had to add code for so
it would reserve those IDs)Thus, anything other than GENL_ID_GENERATE is flawed and
luckily not used except in the cases I mentioned. Move
those workarounds into a few lines of code, and then get
rid of GENL_ID_GENERATE entirely, making it more robust.Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller
24 Apr, 2016
1 commit
-
Goal of this patch is to use the new libnl API to align netlink attribute
when needed.
The layout of the netlink message will be a bit different after the patch,
because the padattr (TASKSTATS_TYPE_STATS) will be inside the nested
attribute instead of before it.Signed-off-by: Nicolas Dichtel
Signed-off-by: David S. Miller
18 Jan, 2015
1 commit
-
Contrary to common expectations for an "int" return, these functions
return only a positive value -- if used correctly they cannot even
return 0 because the message header will necessarily be in the skb.This makes the very common pattern of
if (genlmsg_end(...) < 0) { ... }
be a whole bunch of dead code. Many places also simply do
return nlmsg_end(...);
and the caller is expected to deal with it.
This also commonly (at least for me) causes errors, because it is very
common to writeif (my_function(...))
/* error condition */and if my_function() does "return nlmsg_end()" this is of course wrong.
Additionally, there's not a single place in the kernel that actually
needs the message length returned, and if anyone needs it later then
it'll be very easy to just use skb->len there.Remove this, and make the functions void. This removes a bunch of dead
code as described above. The patch adds lines because I did- return nlmsg_end(...);
+ nlmsg_end(...);
+ return 0;I could have preserved all the function's return values by returning
skb->len, but instead I've audited all the places calling the affected
functions and found that none cared. A few places actually compared
the return value with < 0 with no change in behaviour, so I opted for the more
efficient version.One instance of the error I've made numerous times now is also present
in net/phonet/pn_netlink.c in the route_dumpit() function - it didn't
check for
Signed-off-by: David S. Miller
20 Nov, 2014
1 commit
-
Signed-off-by: Al Viro
27 Aug, 2014
1 commit
-
Convert all uses of __get_cpu_var for address calculation to use
this_cpu_ptr instead.[Uses of __get_cpu_var with cpumask_var_t are no longer
handled by this patch]Cc: Peter Zijlstra
Acked-by: Ingo Molnar
Signed-off-by: Christoph Lameter
Signed-off-by: Tejun Heo
20 Nov, 2013
1 commit
-
As suggested by David Miller, make genl_register_family_with_ops()
a macro and pass only the array, evaluating ARRAY_SIZE() in the
macro, this is a little safer.The openvswitch has some indirection, assing ops/n_ops directly in
that code. This might ultimately just assign the pointers in the
family initializations, saving the struct genl_family_and_ops and
code (once mcast groups are handled differently.)Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller
15 Nov, 2013
2 commits
-
Now that genl_ops are no longer modified in place when
registering, they can be made const. This patch was done
mostly with spatch:@@
identifier ops;
@@
+const
struct genl_ops ops[] = {
...
};(except the struct thing in net/openvswitch/datapath.c)
Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller -
This simplifies the code since there's no longer a
need to have error handling in the registration.Signed-off-by: Johannes Berg
Signed-off-by: David S. Miller
13 Nov, 2013
2 commits
-
For registering in add_del_listener(), when kmalloc_node() fails, need
return -ENOMEM instead of success code, and cmd_attr_register_cpumask()
wants to know about it.After modification, give a simple common test "build -> boot up ->
kernel/controllers/cgroup/getdelays by LTP tools".Signed-off-by: Chen Gang
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
…t_start() and nla_nest_end()
When failure occurs between nla_nest_start() and nla_nest_end(), we should
call nla_nest_cancel() to clean up related things.Signed-off-by: Chen Gang <gang.chen@asianux.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
06 Oct, 2012
1 commit
-
If prepare_reply() succeeds we have allocated memory for 'rep_skb'. If
nla_reserve() then subsequently fails and returns NULL we fail to release
the memory we allocated, thus causing a leak.Signed-off-by: Jesper Juhl
Cc: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Oct, 2012
2 commits
-
Pull vfs update from Al Viro:
- big one - consolidation of descriptor-related logics; almost all of
that is moved to fs/file.c(BTW, I'm seriously tempted to rename the result to fd.c. As it is,
we have a situation when file_table.c is about handling of struct
file and file.c is about handling of descriptor tables; the reasons
are historical - file_table.c used to be about a static array of
struct file we used to have way back).A lot of stray ends got cleaned up and converted to saner primitives,
disgusting mess in android/binder.c is still disgusting, but at least
doesn't poke so much in descriptor table guts anymore. A bunch of
relatively minor races got fixed in process, plus an ext4 struct file
leak.- related thing - fget_light() partially unuglified; see fdget() in
there (and yes, it generates the code as good as we used to have).- also related - bits of Cyrill's procfs stuff that got entangled into
that work; _not_ all of it, just the initial move to fs/proc/fd.c and
switch of fdinfo to seq_file.- Alex's fs/coredump.c spiltoff - the same story, had been easier to
take that commit than mess with conflicts. The rest is a separate
pile, this was just a mechanical code movement.- a few misc patches all over the place. Not all for this cycle,
there'll be more (and quite a few currently sit in akpm's tree)."Fix up trivial conflicts in the android binder driver, and some fairly
simple conflicts due to two different changes to the sock_alloc_file()
interface ("take descriptor handling from sock_alloc_file() to callers"
vs "net: Providing protocol type via system.sockprotoname xattr of
/proc/PID/fd entries" adding a dentry name to the socket)* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (72 commits)
MAX_LFS_FILESIZE should be a loff_t
compat: fs: Generic compat_sys_sendfile implementation
fs: push rcu_barrier() from deactivate_locked_super() to filesystems
btrfs: reada_extent doesn't need kref for refcount
coredump: move core dump functionality into its own file
coredump: prevent double-free on an error path in core dumper
usb/gadget: fix misannotations
fcntl: fix misannotations
ceph: don't abuse d_delete() on failure exits
hypfs: ->d_parent is never NULL or negative
vfs: delete surplus inode NULL check
switch simple cases of fget_light to fdget
new helpers: fdget()/fdput()
switch o2hb_region_dev_write() to fget_light()
proc_map_files_readdir(): don't bother with grabbing files
make get_file() return its argument
vhost_set_vring(): turn pollstart/pollstop into bool
switch prctl_set_mm_exe_file() to fget_light()
switch xfs_find_handle() to fget_light()
switch xfs_swapext() to fget_light()
... -
Pull networking changes from David Miller:
1) GRE now works over ipv6, from Dmitry Kozlov.
2) Make SCTP more network namespace aware, from Eric Biederman.
3) TEAM driver now works with non-ethernet devices, from Jiri Pirko.
4) Make openvswitch network namespace aware, from Pravin B Shelar.
5) IPV6 NAT implementation, from Patrick McHardy.
6) Server side support for TCP Fast Open, from Jerry Chu and others.
7) Packet BPF filter supports MOD and XOR, from Eric Dumazet and Daniel
Borkmann.8) Increate the loopback default MTU to 64K, from Eric Dumazet.
9) Use a per-task rather than per-socket page fragment allocator for
outgoing networking traffic. This benefits processes that have very
many mostly idle sockets, which is quite common.From Eric Dumazet.
10) Use up to 32K for page fragment allocations, with fallbacks to
smaller sizes when higher order page allocations fail. Benefits are
a) less segments for driver to process b) less calls to page
allocator c) less waste of space.From Eric Dumazet.
11) Allow GRO to be used on GRE tunnels, from Eric Dumazet.
12) VXLAN device driver, one way to handle VLAN issues such as the
limitation of 4096 VLAN IDs yet still have some level of isolation.
From Stephen Hemminger.13) As usual there is a large boatload of driver changes, with the scale
perhaps tilted towards the wireless side this time around.Fix up various fairly trivial conflicts, mostly caused by the user
namespace changes.* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1012 commits)
hyperv: Add buffer for extended info after the RNDIS response message.
hyperv: Report actual status in receive completion packet
hyperv: Remove extra allocated space for recv_pkt_list elements
hyperv: Fix page buffer handling in rndis_filter_send_request()
hyperv: Fix the missing return value in rndis_filter_set_packet_filter()
hyperv: Fix the max_xfer_size in RNDIS initialization
vxlan: put UDP socket in correct namespace
vxlan: Depend on CONFIG_INET
sfc: Fix the reported priorities of different filter types
sfc: Remove EFX_FILTER_FLAG_RX_OVERRIDE_IP
sfc: Fix loopback self-test with separate_tx_channels=1
sfc: Fix MCDI structure field lookup
sfc: Add parentheses around use of bitfield macro arguments
sfc: Fix null function pointer in efx_sriov_channel_type
vxlan: virtual extensible lan
igmp: export symbol ip_mc_leave_group
netlink: add attributes to fdb interface
tg3: unconditionally select HWMON support when tg3 is enabled.
Revert "net: ti cpsw ethernet: allow reading phy interface mode from DT"
gre: fix sparse warning
...
27 Sep, 2012
1 commit
-
Signed-off-by: Al Viro
18 Sep, 2012
1 commit
-
- Explicitly limit exit task stat broadcast to the initial user and
pid namespaces, as it is already limited to the initial network
namespace.- For broadcast task stats explicitly generate all of the idenitiers
in terms of the initial user namespace and the initial pid
namespace.- For request stats report them in terms of the current user namespace
and the current pid namespace. Netlink messages are delivered
syncrhonously to the kernel allowing us to get the user namespace
and the pid namespace from the current task.- Pass the namespaces for representing pids and uids and gids
into bacct_add_task.Cc: Balbir Singh
Signed-off-by: Eric W. Biederman
11 Sep, 2012
1 commit
-
It is a frequent mistake to confuse the netlink port identifier with a
process identifier. Try to reduce this confusion by renaming fields
that hold port identifiers portid instead of pid.I have carefully avoided changing the structures exported to
userspace to avoid changing the userspace API.I have successfully built an allyesconfig kernel with this change.
Signed-off-by: "Eric W. Biederman"
Acked-by: Stephen Hemminger
Signed-off-by: David S. Miller
31 Jul, 2012
1 commit
-
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=44621
Reported-by:
Signed-off-by: Alan Cox
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
20 Sep, 2011
1 commit
-
Ok, this isn't optimal, since it means that 'iotop' needs admin
capabilities, and we may have to work on this some more. But at the
same time it is very much not acceptable to let anybody just read
anybody elses IO statistics quite at this level.Use of the GENL_ADMIN_PERM suggested by Johannes Berg as an alternative
to checking the capabilities by hand.Reported-by: Vasiliy Kulikov
Cc: Johannes Berg
Acked-by: Balbir Singh
Signed-off-by: Linus Torvalds
04 Aug, 2011
2 commits
-
When send_cpu_listeners() finds the orphaned listener it marks it as
!valid and drops listeners->sem. Before it takes this sem for writing,
s->pid can be reused and add_del_listener() can wrongly try to re-use
this entry.Change add_del_listener() to check ->valid = T.
Signed-off-by: Oleg Nesterov
Reviewed-by: Vasiliy Kulikov
Acked-by: Balbir Singh
Cc: Jerome Marchand
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
1. Commit 26c4caea9d69 "don't allow duplicate entries in listener mode"
changed add_del_listener(REGISTER) so that "next_cpu:" can reuse the
listener allocated for the previous cpu, this doesn't look exactly
right even if minor.Change the code to kfree() in the already-registered case, this case
is unlikely anyway so the extra kmalloc_node() shouldn't hurt but
looke more correct and clean.2. use the plain list_for_each_entry() instead of _safe() to scan
listeners->list.3. Remove the unneeded INIT_LIST_HEAD(&s->list), we are going to
list_add(&s->list).Signed-off-by: Oleg Nesterov
Reviewed-by: Vasiliy Kulikov
Cc: Balbir Singh
Reviewed-by: Jerome Marchand
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Jul, 2011
1 commit
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This allows us to move duplicated code in
(atomic_inc_not_zero() for now) toSigned-off-by: Arun Sharma
Reviewed-by: Eric Dumazet
Cc: Ingo Molnar
Cc: David Miller
Cc: Eric Dumazet
Acked-by: Mike Frysinger
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
28 Jun, 2011
1 commit
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Currently a single process may register exit handlers unlimited times.
It may lead to a bloated listeners chain and very slow process
terminations.Eg after 10KK sent TASKSTATS_CMD_ATTR_REGISTER_CPUMASKs ~300 Mb of
kernel memory is stolen for the handlers chain and "time id" shows 2-7
seconds instead of normal 0.003. It makes it possible to exhaust all
kernel memory and to eat much of CPU time by triggerring numerous exits
on a single CPU.The patch limits the number of times a single process may register
itself on a single CPU to one.One little issue is kept unfixed - as taskstats_exit() is called before
exit_files() in do_exit(), the orphaned listener entry (if it was not
explicitly deregistered) is kept until the next someone's exit() and
implicit deregistration in send_cpu_listeners(). So, if a process
registered itself as a listener exits and the next spawned process gets
the same pid, it would inherit taskstats attributes.Signed-off-by: Vasiliy Kulikov
Cc: Balbir Singh
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 Mar, 2011
1 commit
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printk()s without a priority level default to KERN_WARNING. To reduce
noise at KERN_WARNING, this patch set the priority level appriopriately
for unleveled printks()s. This should be useful to folks that look at
dmesg warnings closely.Signed-off-by: Mandeep Singh Baines
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
14 Jan, 2011
1 commit
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Commit 4be2c95d ("taskstats: pad taskstats netlink response for aligment
issues on ia64") added a null field to align the taskstats structure but
the discussion centered around ia64. The issue exists on other platforms
with inefficient unaligned access and adding them piecemeal would be an
unmaintainable mess.This patch uses Dave Miller's suggestion of using a combination of
CONFIG_64BIT && !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS to determine
whether alignment is needed.Note that this will cause breakage on those platforms with applications
like iotop which had hard-coded offsets into the packet to access the
taskstats structure.The message seen on systems without the alignment fixes looks like: kernel
unaligned access to 0xe000023879dca9bc, ip=0xa000000100133d10The addresses may vary but resolve to locations inside __delayacct_add_tsk.
iotop makes what I'd call unreasonable assumptions about the contents of a
netlink genetlink packet containing generic attributes. They're typed and
have headers that specify value lengths, so the client can (should)
identify and skip the ones the client doesn't understand.The kernel, as of version 2.6.36, presented a packet like so:
+--------------------------------+
| genlmsghdr - 4 bytes |
+--------------------------------+
| NLA header - 4 bytes | /* Aggregate header */
+-+------------------------------+
| | NLA header - 4 bytes | /* PID header */
| +------------------------------+
| | pid/tgid - 4 bytes |
| +------------------------------+
| | NLA header - 4 bytes | /* stats header */
| + -----------------------------+
Reported-by: David S. Miller
Acked-by: David S. Miller
Cc: Dan Carpenter
Cc: Balbir Singh
Cc: Florian Mickler
Cc: Guillaume Chazarain
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Jan, 2011
1 commit
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* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (30 commits)
gameport: use this_cpu_read instead of lookup
x86: udelay: Use this_cpu_read to avoid address calculation
x86: Use this_cpu_inc_return for nmi counter
x86: Replace uses of current_cpu_data with this_cpu ops
x86: Use this_cpu_ops to optimize code
vmstat: User per cpu atomics to avoid interrupt disable / enable
irq_work: Use per cpu atomics instead of regular atomics
cpuops: Use cmpxchg for xchg to avoid lock semantics
x86: this_cpu_cmpxchg and this_cpu_xchg operations
percpu: Generic this_cpu_cmpxchg() and this_cpu_xchg support
percpu,x86: relocate this_cpu_add_return() and friends
connector: Use this_cpu operations
xen: Use this_cpu_inc_return
taskstats: Use this_cpu_ops
random: Use this_cpu_inc_return
fs: Use this_cpu_inc_return in buffer.c
highmem: Use this_cpu_xx_return() operations
vmstat: Use this_cpu_inc_return for vm statistics
x86: Support for this_cpu_add, sub, dec, inc_return
percpu: Generic support for this_cpu_add, sub, dec, inc_return
...Fixed up conflicts: in arch/x86/kernel/{apic/nmi.c, apic/x2apic_uv_x.c, process.c}
as per Tejun.
23 Dec, 2010
1 commit
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The taskstats structure is internally aligned on 8 byte boundaries but the
layout of the aggregrate reply, with two NLA headers and the pid (each 4
bytes), actually force the entire structure to be unaligned. This causes
the kernel to issue unaligned access warnings on some architectures like
ia64. Unfortunately, some software out there doesn't properly unroll the
NLA packet and assumes that the start of the taskstats structure will
always be 20 bytes from the start of the netlink payload. Aligning the
start of the taskstats structure breaks this software, which we don't
want. So, for now the alignment only happens on architectures that
require it and those users will have to update to fixed versions of those
packages. Space is reserved in the packet only when needed. This ifdef
should be removed in several years e.g. 2012 once we can be confident
that fixed versions are installed on most systems. We add the padding
before the aggregate since the aggregate is already a defined type.Commit 85893120 ("delayacct: align to 8 byte boundary on 64-bit systems")
previously addressed the alignment issues by padding out the pid field.
This was supposed to be a compatible change but the circumstances
described above mean that it wasn't. This patch backs out that change,
since it was a hack, and introduces a new NULL attribute type to provide
the padding. Padding the response with 4 bytes avoids allocating an
aligned taskstats structure and copying it back. Since the structure
weighs in at 328 bytes, it's too big to do it on the stack.Signed-off-by: Jeff Mahoney
Reported-by: Brian Rogers
Cc: Jeff Mahoney
Cc: Guillaume Chazarain
Cc: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Dec, 2010
1 commit
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Use this_cpu_inc_return in one place and avoid ugly __raw_get_cpu in
another.V3->V4:
- Fix off by one.V4-V4f:
- Use &listener_arrayCc: Michael Holzheu
Acked-by: H. Peter Anvin
Signed-off-by: Christoph Lameter
Signed-off-by: Tejun Heo
28 Oct, 2010
1 commit
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Separate the finding of a task_struct by pid or tgid from filling the
taskstats data. This makes the code more readable.Signed-off-by: Michael Holzheu
Acked-by: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
