Since the ability to swap the cpu buffers adds a small overhead to
the recording of a trace, we only want to add it when needed.
Only the irqsoff and preemptoff tracers use this feature, and both are
not recommended for production kernels. This patch disables its use
when neither irqsoff nor preemptoff is configured.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The latency tracers (irqsoff and wakeup) can swap trace buffers
on the fly. If an event is happening and has reserved data on one of
the buffers, and the latency tracer swaps the global buffer with the
max buffer, the result is that the event may commit the data to the
wrong buffer.
This patch changes the API to the trace recording to be recieve the
buffer that was used to reserve a commit. Then this buffer can be passed
in to the commit.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Device-mapper userspace logs (like the clustered log) are
identified by a universally unique identifier (UUID). This
identifier is used to associate requests from the kernel to
a specific log in userspace. The UUID must be unique everywhere,
since multiple machines may use this identifier when communicating
about a particular log, as is the case for cluster logs.
Sometimes, device-mapper/LVM may re-use a UUID. This is the
case during pvmoves, when moving from one segment of an LV
to another, or when resizing a mirror, etc. In these cases,
a new log is created with the same UUID and loaded in the
"inactive" slot. When a device-mapper "resume" is issued,
the "live" table is deactivated and the new "inactive" table
becomes "live". (The "inactive" table can also be removed
via a device-mapper 'clear' command.)
The above two issues were colliding. More than one log was being
created with the same UUID, and there was no way to distinguish
between them. So, sometimes the wrong log would be swapped
out during the exchange.
The solution is to create a locally unique identifier,
'luid', to go along with the UUID. This new identifier is used
to determine exactly which log is being referenced by the kernel
when the log exchange is made. The identifier is not
universally safe, but it does not need to be, since
create/destroy/suspend/resume operations are bound to a specific
machine; and these are the operations that make up the exchange.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Set sensible I/O hints for striped DM devices in the topology
infrastructure added for 2.6.31 for userspace tools to
obtain via sysfs.
Add .io_hints to 'struct target_type' to allow the I/O hints portion
(io_min and io_opt) of the 'struct queue_limits' to be set by each
target and implement this for dm-stripe.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
The function ring_buffer_event_discard can be used on any item in the
ring buffer, even after the item was committed. This function provides
no safety nets and is very race prone.
An item may be safely removed from the ring buffer before it is committed
with the ring_buffer_discard_commit.
Since there are currently no users of this function, and because this
function is racey and error prone, this patch removes it altogether.
Note, removing this function also allows the counters to ignore
all discarded events (patches will follow).
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Ingo Molnar reported the following kmemcheck warning when running both
kmemleak and kmemcheck enabled:
PM: Adding info for No Bus:vcsa7
WARNING: kmemcheck: Caught 32-bit read from uninitialized memory
(f6f6e1a4)
d873f9f600000000c42ae4c1005c87f70000000070665f666978656400000000
i i i i u u u u i i i i i i i i i i i i i i i i i i i i i u u u
^
Pid: 3091, comm: kmemleak Not tainted (2.6.31-rc7-tip #1303) P4DC6
EIP: 0060:[<c110301f>] EFLAGS: 00010006 CPU: 0
EIP is at scan_block+0x3f/0xe0
EAX: f40bd700 EBX: f40bd780 ECX: f16b46c0 EDX: 00000001
ESI: f6f6e1a4 EDI: 00000000 EBP: f10f3f4c ESP: c2605fcc
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
CR0: 8005003b CR2: e89a4844 CR3: 30ff1000 CR4: 000006f0
DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
DR6: ffff4ff0 DR7: 00000400
[<c110313c>] scan_object+0x7c/0xf0
[<c1103389>] kmemleak_scan+0x1d9/0x400
[<c1103a3c>] kmemleak_scan_thread+0x4c/0xb0
[<c10819d4>] kthread+0x74/0x80
[<c10257db>] kernel_thread_helper+0x7/0x3c
[<ffffffff>] 0xffffffff
kmemleak: 515 new suspected memory leaks (see
/sys/kernel/debug/kmemleak)
kmemleak: 42 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
The problem here is that kmemleak will scan partially initialized
objects that makes kmemcheck complain. Fix that up by skipping
uninitialized memory regions when kmemcheck is enabled.
Reported-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Re-organize the flag settings so that it's visible at a glance
which sched-domains flags are set and which not.
With the new balancer code we'll need to re-tune these details
anyway, so make it cleaner to make fewer mistakes down the
road ;-)
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Its a source of fail, also, now that cpu_power is dynamical,
its a waste of time.
before:
<idle>-0 [000] 132.877936: find_busiest_group: avg_load: 0 group_load: 8241 power: 1
after:
bash-1689 [001] 137.862151: find_busiest_group: avg_load: 10636288 group_load: 10387 power: 1
[ v2: build fix from From: Andreas Herrmann ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Acked-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Acked-by: Gautham R Shenoy <ego@in.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
LKML-Reference: <20090901083826.425896304@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add a keyctl to install a process's session keyring onto its parent. This
replaces the parent's session keyring. Because the COW credential code does
not permit one process to change another process's credentials directly, the
change is deferred until userspace next starts executing again. Normally this
will be after a wait*() syscall.
To support this, three new security hooks have been provided:
cred_alloc_blank() to allocate unset security creds, cred_transfer() to fill in
the blank security creds and key_session_to_parent() - which asks the LSM if
the process may replace its parent's session keyring.
The replacement may only happen if the process has the same ownership details
as its parent, and the process has LINK permission on the session keyring, and
the session keyring is owned by the process, and the LSM permits it.
Note that this requires alteration to each architecture's notify_resume path.
This has been done for all arches barring blackfin, m68k* and xtensa, all of
which need assembly alteration to support TIF_NOTIFY_RESUME. This allows the
replacement to be performed at the point the parent process resumes userspace
execution.
This allows the userspace AFS pioctl emulation to fully emulate newpag() and
the VIOCSETTOK and VIOCSETTOK2 pioctls, all of which require the ability to
alter the parent process's PAG membership. However, since kAFS doesn't use
PAGs per se, but rather dumps the keys into the session keyring, the session
keyring of the parent must be replaced if, for example, VIOCSETTOK is passed
the newpag flag.
This can be tested with the following program:
#include <stdio.h>
#include <stdlib.h>
#include <keyutils.h>
#define KEYCTL_SESSION_TO_PARENT 18
#define OSERROR(X, S) do { if ((long)(X) == -1) { perror(S); exit(1); } } while(0)
int main(int argc, char **argv)
{
key_serial_t keyring, key;
long ret;
keyring = keyctl_join_session_keyring(argv[1]);
OSERROR(keyring, "keyctl_join_session_keyring");
key = add_key("user", "a", "b", 1, keyring);
OSERROR(key, "add_key");
ret = keyctl(KEYCTL_SESSION_TO_PARENT);
OSERROR(ret, "KEYCTL_SESSION_TO_PARENT");
return 0;
}
Compiled and linked with -lkeyutils, you should see something like:
[dhowells@andromeda ~]$ keyctl show
Session Keyring
-3 --alswrv 4043 4043 keyring: _ses
355907932 --alswrv 4043 -1 \_ keyring: _uid.4043
[dhowells@andromeda ~]$ /tmp/newpag
[dhowells@andromeda ~]$ keyctl show
Session Keyring
-3 --alswrv 4043 4043 keyring: _ses
1055658746 --alswrv 4043 4043 \_ user: a
[dhowells@andromeda ~]$ /tmp/newpag hello
[dhowells@andromeda ~]$ keyctl show
Session Keyring
-3 --alswrv 4043 4043 keyring: hello
340417692 --alswrv 4043 4043 \_ user: a
Where the test program creates a new session keyring, sticks a user key named
'a' into it and then installs it on its parent.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Add garbage collection for dead, revoked and expired keys. This involved
erasing all links to such keys from keyrings that point to them. At that
point, the key will be deleted in the normal manner.
Keyrings from which garbage collection occurs are shrunk and their quota
consumption reduced as appropriate.
Dead keys (for which the key type has been removed) will be garbage collected
immediately.
Revoked and expired keys will hang around for a number of seconds, as set in
/proc/sys/kernel/keys/gc_delay before being automatically removed. The default
is 5 minutes.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Add a config option (CONFIG_DEBUG_CREDENTIALS) to turn on some debug checking
for credential management. The additional code keeps track of the number of
pointers from task_structs to any given cred struct, and checks to see that
this number never exceeds the usage count of the cred struct (which includes
all references, not just those from task_structs).
Furthermore, if SELinux is enabled, the code also checks that the security
pointer in the cred struct is never seen to be invalid.
This attempts to catch the bug whereby inode_has_perm() faults in an nfsd
kernel thread on seeing cred->security be a NULL pointer (it appears that the
credential struct has been previously released):
http://www.kerneloops.org/oops.php?number=252883
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
For counting how long an application has been waiting for
(disk) IO, there currently is only the HZ sample driven
information available, while for all other counters in this
class, a high resolution version is available via
CONFIG_SCHEDSTATS.
In order to make an improved bootchart tool possible, we also
need a higher resolution version of the iowait time.
This patch below adds this scheduler statistic to the kernel.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4A64B813.1080506@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Merge reason: bump from rc5 to rc8, but also pick up TP_perf_assign()
API, a patch will be queued that depends on it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This was a hack to give userland shutdown tools time to drop manual
spindown. All popular distros updated quite some time ago and the due
is well passed. Drop it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This patch improve libata's output for error/notification messages
to allow easier comprehension and debugging:
When ATAPI commands issued through the SCSI layer fail, use SCSI
functions to print the CDB in human-readable form instead of just
dumping out the CDB in hex.
Print out the name of the failed command (as defined by the ATA
specification) in error handling output along with the raw register
contents.
When reporting status of ACPI taskfile commands executed on resume,
also output the names of the commands being executed (or not) in
readable form.
Since the extra data for printing command names increases kernel
size slightly, a config option has been added to allow disabling
command name output (as well as some of the error register parsing)
for those highly sensitive to kernel text size.
Signed-off-by: Robert Hancock <hancockrwd@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Hopefully results in fewer on-the-wire FIS's and no breakage. We'll see!
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
My previous patch (commit 4f8ee2c9cc: "lmb: Remove __init from
lmb_end_of_DRAM()") removed __init in lmb.c but missed the fact that it
was also marked as such in the .h
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The TUN driver lacks any LSM hooks which makes it difficult for LSM modules,
such as SELinux, to enforce access controls on network traffic generated by
TUN users; this is particularly problematic for virtualization apps such as
QEMU and KVM. This patch adds three new LSM hooks designed to control the
creation and attachment of TUN devices, the hooks are:
* security_tun_dev_create()
Provides access control for the creation of new TUN devices
* security_tun_dev_post_create()
Provides the ability to create the necessary socket LSM state for newly
created TUN devices
* security_tun_dev_attach()
Provides access control for attaching to existing, persistent TUN devices
and the ability to update the TUN device's socket LSM state as necessary
Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Eric Paris <eparis@parisplace.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Morris <jmorris@namei.org>
init_preds() allocates about 5392 bytes of memory (on x86_32) for
a TRACE_EVENT. With my config, at system boot total memory occupied
is:
5392 * (642 + 15) == 3459KB
642 == cat available_events | wc -l
15 == number of dirs in events/ftrace
That's quite a lot, so we'd better defer memory allocation util
it's needed, that's when filter is used.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
LKML-Reference: <4A9B8EA5.6020700@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This buffer isn't needed after kmemleak was initialised so it can be
freed together with the .init.data section. This patch also marks
functions conditionally accessing the early log variables with __ref.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
It's problematic to allow signed element_nr's or total's to be passed as
part of the flex array API.
flex_array_alloc() allows total_nr_elements to be set to a negative
quantity, which is obviously erroneous.
flex_array_get() and flex_array_put() allows negative array indices in
dereferencing an array part, which could address memory mapped before
struct flex_array.
The fix is to convert all existing element_nr formals to be qualified as
unsigned. Existing checks to compare it to total_nr_elements or the max
array size based on element_size need not be changed.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The `parts' member of struct flex_array should evaluate to an incomplete
type so that sizeof() cannot be used and C99 does not require the
zero-length specification.
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The commit:
commit 5ac35daa93
Author: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
tracing/events: fix the include file dependencies
Moved the TRACE_EVENT out of the ifdef protection of tracepoints.h
but uses the define of TRACE_EVENT itself as protection. This patch
adds comments to explain why.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The TRACE_EVENT depends on the include/linux/tracepoint.h first
and include/trace/ftrace.h later, if we include the ftrace.h early,
a building error will occur.
Both define TRACE_EVENT in trace_a.h and trace_b.h, if we include
those in .c file, like this:
#define CREATE_TRACE_POINTS
include <trace/events/trace_a.h>
include <trace/events/trace_b.h>
The above will not work, because the TRACE_EVENT was re-defined by
the previous .h file.
Reported-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
LKML-Reference: <4A937F5E.3020802@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Usually, char * entries are dangerous in traces because the string
can be released whereas a pointer to it can still wait to be read from
the ring buffer.
But sometimes we can assume it's safe, like in case of RO data
(eg: __file__ or __line__, used in bkl trace event). If these RO data
are in a module and so is the call to the trace event, then it's safe,
because the ring buffer will be flushed once this module get unloaded.
To allow char * to be treated as a string:
TRACE_EVENT(...,
TP_STRUCT__entry(
__field_ext(const char *, name, FILTER_PTR_STRING)
...
)
...
);
The filtering will not dereference "char *" unless the developer
explicitly sets FILTER_PTR_STR in __field_ext.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4A7B9287.90205@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add __field_ext(), so a field can be assigned to a specific
filter_type, which matches a corresponding filter function.
For example, a later patch will allow this:
__field_ext(const char *, str, FILTER_PTR_STR);
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4A7B9272.6050709@cn.fujitsu.com>
[
Fixed a -1 to FILTER_OTHER
Forward ported to latest kernel.
]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
It's not strictly correct for the tracepoint reg/unreg callbacks to
occur when a client is hooking up, because the actual tracepoint may not
be present yet. This happens to be fine for syscall, since that's in
the core kernel, but it would cause problems for tracepoints defined in
a module that hasn't been loaded yet. It also means the reg/unreg has
to be EXPORTed for any modules to use the tracepoint (as in SystemTap).
This patch removes DECLARE_TRACE_WITH_CALLBACK, and instead introduces
DEFINE_TRACE_FN which stores the callbacks in struct tracepoint. The
callbacks are used now when the active state of the tracepoint changes
in set_tracepoint & disable_tracepoint.
This also introduces TRACE_EVENT_FN, so ftrace events can also provide
registration callbacks if needed.
Signed-off-by: Josh Stone <jistone@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
LKML-Reference: <1251150194-1713-4-git-send-email-jistone@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2.6.30's commit 8a0bdec194 removed
user_shm_lock() calls in hugetlb_file_setup() but left the
user_shm_unlock call in shm_destroy().
In detail:
Assume that can_do_hugetlb_shm() returns true and hence user_shm_lock()
is not called in hugetlb_file_setup(). However, user_shm_unlock() is
called in any case in shm_destroy() and in the following
atomic_dec_and_lock(&up->__count) in free_uid() is executed and if
up->__count gets zero, also cleanup_user_struct() is scheduled.
Note that sched_destroy_user() is empty if CONFIG_USER_SCHED is not set.
However, the ref counter up->__count gets unexpectedly non-positive and
the corresponding structs are freed even though there are live
references to them, resulting in a kernel oops after a lots of
shmget(SHM_HUGETLB)/shmctl(IPC_RMID) cycles and CONFIG_USER_SCHED set.
Hugh changed Stefan's suggested patch: can_do_hugetlb_shm() at the
time of shm_destroy() may give a different answer from at the time
of hugetlb_file_setup(). And fixed newseg()'s no_id error path,
which has missed user_shm_unlock() ever since it came in 2.6.9.
Reported-by: Stefan Huber <shuber2@gmail.com>
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Tested-by: Stefan Huber <shuber2@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vfs_read() offset is defined as loff_t, but kernel_read()
offset is only defined as unsigned long. Redefine
kernel_read() offset as loff_t.
Cc: stable@kernel.org
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
