Remove needless kprobe_insn_mutex unlocking during safety check
in garbage collection, because if someone releases a dirty slot
during safety check (which ensures other cpus doesn't execute
all dirty slots), the safety check must be fail. So, we need to
hold the mutex while checking safety.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
LKML-Reference: <20090630210809.17851.28781.stgit@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'kmemleak' of git://linux-arm.org/linux-2.6:
kmemleak: Inform kmemleak about pid_hash
kmemleak: Do not warn if an unknown object is freed
kmemleak: Do not report new leaked objects if the scanning was stopped
kmemleak: Slightly change the policy on newly allocated objects
kmemleak: Do not trigger a scan when reading the debug/kmemleak file
kmemleak: Simplify the reports logged by the scanning thread
kmemleak: Enable task stacks scanning by default
kmemleak: Allow the early log buffer to be configurable.
* 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (47 commits)
perf report: Add --symbols parameter
perf report: Add --comms parameter
perf report: Add --dsos parameter
perf_counter tools: Adjust only prelinked symbol's addresses
perf_counter: Provide a way to enable counters on exec
perf_counter tools: Reduce perf stat measurement overhead/skew
perf stat: Use percentages for scaling output
perf_counter, x86: Update x86_pmu after WARN()
perf stat: Micro-optimize the code: memcpy is only required if no event is selected and !null_run
perf stat: Improve output
perf stat: Fix multi-run stats
perf stat: Add -n/--null option to run without counters
perf_counter tools: Remove dead code
perf_counter: Complete counter swap
perf report: Print sorted callchains per histogram entries
perf_counter tools: Prepare a small callchain framework
perf record: Fix unhandled io return value
perf_counter tools: Add alias for 'l1d' and 'l1i'
perf-report: Add bare minimum PERF_EVENT_READ parsing
perf-report: Add modes for inherited stats and no-samples
...
The file opened in acct_on and freshly stored in the ns->bacct struct can
be closed in acct_file_reopen by a concurrent call after we release
acct_lock and before we call mntput(file->f_path.mnt).
Record file->f_path.mnt in a local variable and use this variable only.
Signed-off-by: Renaud Lottiaux <renaud.lottiaux@kerlabs.com>
Signed-off-by: Louis Rilling <louis.rilling@kerlabs.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When the 32-bit signed quantities get assigned to the u64 resource_size_t,
they are incorrectly sign-extended.
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13253
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=9905
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Reported-by: Leann Ogasawara <leann@ubuntu.com>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Reported-by: <pablomme@googlemail.com>
Tested-by: <pablomme@googlemail.com>
Cc: <stable@kernel.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This provides a way to mark a counter to be enabled on the next
exec. This is useful for measuring the total activity of a
program without including overhead from the process that
launches it.
This also changes the perf stat command to use this new
facility.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <19017.43927.838745.689203@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Kmemleak does not track alloc_bootmem calls but the pid_hash allocated
in pidhash_init() would need to be scanned as it contains pointers to
struct pid objects.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
To use boot tracer, one should pass initcall_debug as well as
ftrace=initcall to the command line.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4A48735E.9050002@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, delay: tsc based udelay should have rdtsc_barrier
x86, setup: correct include file in <asm/boot.h>
x86, setup: Fix typo "CONFIG_x86_64" in <asm/boot.h>
x86, mce: percpu mcheck_timer should be pinned
x86: Add sysctl to allow panic on IOCK NMI error
x86: Fix uv bau sending buffer initialization
x86, mce: Fix mce resume on 32bit
x86: Move init_gbpages() to setup_arch()
x86: ensure percpu lpage doesn't consume too much vmalloc space
x86: implement percpu_alloc kernel parameter
x86: fix pageattr handling for lpage percpu allocator and re-enable it
x86: reorganize cpa_process_alias()
x86: prepare setup_pcpu_lpage() for pageattr fix
x86: rename remap percpu first chunk allocator to lpage
x86: fix duplicate free in setup_pcpu_remap() failure path
percpu: fix too lazy vunmap cache flushing
x86: Set cpu_llc_id on AMD CPUs
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
timer stats: Optimize by adding quick check to avoid function calls
timers: Fix timer_migration interface which accepts any number as input
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
ftrace: Fix the output of profile
ring-buffer: Make it generally available
ftrace: Remove duplicate newline
tracing: Fix trace_buf_size boot option
ftrace: Fix t_hash_start()
ftrace: Don't manipulate @pos in t_start()
ftrace: Don't increment @pos in g_start()
tracing: Reset iterator in t_start()
trace_stat: Don't increment @pos in seq start()
tracing_bprintk: Don't increment @pos in t_start()
tracing/events: Don't increment @pos in s_start()
Some fields for struct ftrace_graph_ret are missed
when they are exported to user.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4A448FB6.5000302@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This made my machine completely frozen:
# echo 1 > /proc/sys/kernel/stack_tracer_enabled
# echo 2 > /proc/sys/kernel/stack_tracer_enabled
The cause is register_ftrace_function() was called twice.
Also fix ftrace_enabled sysctl, though seems nothing bad happened
as I tested it.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A448D17.9010305@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Complete the counter swap by indeed switching the times too and
updating the userpage after modifying the counter values.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1246014623.31755.195.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The first entry of the ftrace profile was always skipped when
reading trace_stat/functionX.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A443D59.4080307@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch introduces a new sysctl:
/proc/sys/kernel/panic_on_io_nmi
which defaults to 0 (off).
When enabled, the kernel panics when the kernel receives an NMI
caused by an IO error.
The IO error triggered NMI indicates a serious system
condition, which could result in IO data corruption. Rather
than contiuing, panicing and dumping might be a better choice,
so one can figure out what's causing the IO error.
This could be especially important to companies running IO
intensive applications where corruption must be avoided, e.g. a
bank's databases.
[ SuSE has been shipping it for a while, it was done at the
request of a large database vendor, for their users. ]
Signed-off-by: Kurt Garloff <garloff@suse.de>
Signed-off-by: Roberto Angelino <robertangelino@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
LKML-Reference: <20090624213211.GA11291@kroah.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The PERF_EVENT_READ implementation made me realize we don't
actually need the sample_type int the output sample, since
we already have that in the perf_counter_attr information.
Therefore, remove the PERF_EVENT_MISC_OVERFLOW bit and the
event->type overloading, and imply put counter overflow
samples in a PERF_EVENT_SAMPLE type.
This also fixes the issue that event->type was only 32-bit
and sample_type had 64 usable bits.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
With the introduction of PERF_EVENT_READ we have the
possibility to provide accurate counter values for
individual tasks in a task hierarchy.
However, due to the lazy context switching used for similar
counter contexts our current per task counts are way off.
In order to maintain some of the lazy switch benefits we
don't disable it out-right, but simply iterate the active
counters and flip the values between the contexts.
This only reads the counters but does not need to reprogram
the full PMU.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Provide a read() like event which can be used to log the
counter value at specific sites such as child->parent
folding on exit.
In order to be useful, we log the counter parent ID, not the
actual counter ID, since userspace can only relate parent
IDs to perf_counter_attr constructs.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Update the mmap control page with the needed information to
use the userspace RDPMC instruction for self monitoring.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add the needed time scale to the self-profile mmap information.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Yanmin noticed that fault_in_user_writeable() requests 4 pages instead
of one.
That's the result of blindly trusting Linus' proposal :) I even looked
up the prototype to verify the correctness: the argument in question
is confusingly enough named "len" while in reality it means number of
pages.
Pointed-out-by: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
In hunting down the cause for the hwlat_detector ring buffer spew in
my failed -next builds it became obvious that folks are now treating
ring_buffer as something that is generic independent of tracing and thus,
suitable for public driver consumption.
Given that there are only a few minor areas in ring_buffer that have any
reliance on CONFIG_TRACING or CONFIG_FUNCTION_TRACER, provide stubs for
those and make it generally available.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Cc: Jon Masters <jcm@jonmasters.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20090625053012.GB19944@linux-sh.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
another race fix in jfs_check_acl()
Get "no acls for this inode" right, fix shmem breakage
inline functions left without protection of ifdef (acl)
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current:
audit: inode watches depend on CONFIG_AUDIT not CONFIG_AUDIT_SYSCALL
Even though one cannot make use of the audit watch code without
CONFIG_AUDIT_SYSCALL the spaghetti nature of the audit code means that
the audit rule filtering requires that it at least be compiled.
Thus build the audit_watch code when we build auditfilter like it was
before cfcad62c74
Clearly this is a point of potential future cleanup..
Reported-by: Frans Pop <elendil@planet.nl>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
commit 64d1304a64 (futex: setup writeable mapping for futex ops which
modify user space data) did address only half of the problem of write
access faults.
The patch was made on two wrong assumptions:
1) access_ok(VERIFY_WRITE,...) would actually check write access.
On x86 it does _NOT_. It's a pure address range check.
2) a RW mapped region can not go away under us.
That's wrong as well. Nobody can prevent another thread to call
mprotect(PROT_READ) on that region where the futex resides. If that
call hits between the get_user_pages_fast() verification and the
actual write access in the atomic region we are toast again.
The solution is to not rely on access_ok and get_user() for any write
access related fault on private and shared futexes. Instead we need to
fault it in with verification of write access.
There is no generic non destructive write mechanism which would fault
the user page in trough a #PF, but as we already know that we will
fault we can as well call get_user_pages() directly and avoid the #PF
overhead.
If get_user_pages() returns -EFAULT we know that we can not fix it
anymore and need to bail out to user space.
Remove a bunch of confusing comments on this issue as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
We should be able to specify [KMG] when setting trace_buf_size
boot option, as documented in kernel-parameters.txt
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A41F2DB.4020102@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When the kernel is configured with CONFIG_TIMER_STATS but timer
stats are runtime disabled we still get calls to
__timer_stats_timer_set_start_info which initializes some
fields in the corresponding struct timer_list.
So add some quick checks in the the timer stats setup functions
to avoid function calls to __timer_stats_timer_set_start_info
when timer stats are disabled.
In an artificial workload that does nothing but playing ping
pong with a single tcp packet via loopback this decreases cpu
consumption by 1 - 1.5%.
This is part of a modified function trace output on SLES11:
perl-2497 [00] 28630647177732388 [+ 125]: sk_reset_timer <-tcp_v4_rcv
perl-2497 [00] 28630647177732513 [+ 125]: mod_timer <-sk_reset_timer
perl-2497 [00] 28630647177732638 [+ 125]: __timer_stats_timer_set_start_info <-mod_timer
perl-2497 [00] 28630647177732763 [+ 125]: __mod_timer <-mod_timer
perl-2497 [00] 28630647177732888 [+ 125]: __timer_stats_timer_set_start_info <-__mod_timer
perl-2497 [00] 28630647177733013 [+ 93]: lock_timer_base <-__mod_timer
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mustafa Mesanovic <mustafa.mesanovic@de.ibm.com>
Cc: Arjan van de Ven <arjan@infradead.org>
LKML-Reference: <20090623153811.GA4641@osiris.boeblingen.de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When the output of set_ftrace_filter is larger than PAGE_SIZE,
t_hash_start() will be called the 2nd time, and then we start
from the head of a hlist, which is wrong and causes some entries
to be outputed twice.
The worse is, if the hlist is large enough, reading set_ftrace_filter
won't stop but in a dead loop.
Reviewed-by: Liming Wang <liming.wang@windriver.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A41876E.2060407@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It's rather confusing that in t_start(), in some cases @pos is
incremented, and in some cases it's decremented and then incremented.
This patch rewrites t_start() in a much more general way.
Thus we fix a bug that if ftrace_filtered == 1, functions have tracer
hooks won't be printed, because the branch is always unreachable:
static void *t_start(...)
{
...
if (!p)
return t_hash_start(m, pos);
return p;
}
Before:
# echo 'sys_open' > /mnt/tracing/set_ftrace_filter
# echo 'sys_write:traceon:4' >> /mnt/tracing/set_ftrace_filter
sys_open
After:
# echo 'sys_open' > /mnt/tracing/set_ftrace_filter
# echo 'sys_write:traceon:4' >> /mnt/tracing/set_ftrace_filter
sys_open
sys_write:traceon:count=4
Reviewed-by: Liming Wang <liming.wang@windriver.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A41874B.4090507@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It's wrong to increment @pos in g_start(). It causes some entries
lost when reading set_graph_function, if the output of the file
is larger than PAGE_SIZE.
Reviewed-by: Liming Wang <liming.wang@windriver.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A418738.7090401@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The iterator is m->private, but it's not reset to trace_types in
t_start(). If the output is larger than PAGE_SIZE and t_start()
is called the 2nd time, things will go wrong.
Reviewed-by: Liming Wang <liming.wang@windriver.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A418728.5020506@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It's wrong to increment @pos in stat_seq_start(). It causes some
stat entries lost when reading stat file, if the output of the file
is larger than PAGE_SIZE.
Reviewed-by: Liming Wang <liming.wang@windriver.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A418716.90209@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It's wrong to increment @pos in t_start(), otherwise we'll lose
some entries when reading printk_formats, if the output is larger
than PAGE_SIZE.
Reported-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Reviewed-by: Liming Wang <liming.wang@windriver.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A4186FA.1020106@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
While testing syscall tracepoints posted by Jason, I found 3 entries
were missing when reading available_events. The output size of
available_events is < 4 pages, which means we lost 1 entry per page.
The cause is, it's wrong to increment @pos in s_start().
Actually there's another bug here -- reading avaiable_events/set_events
can race with module unload:
# cat available_events |
s_start() |
s_stop() |
| # rmmod foo.ko
s_start() |
call = list_entry(m->private) |
@call might be freed and accessing it will lead to crash.
Reviewed-by: Liming Wang <liming.wang@windriver.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A4186DD.6090405@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If syscall removes the root of subtree being watched, we
definitely do not want the rules refering that subtree
to be destroyed without the syscall in question having
a chance to match them.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
A number of places in the audit system we send an op= followed by a string
that includes spaces. Somehow this works but it's just wrong. This patch
moves all of those that I could find to be quoted.
Example:
Change From: type=CONFIG_CHANGE msg=audit(1244666690.117:31): auid=0 ses=1
subj=unconfined_u:unconfined_r:auditctl_t:s0-s0:c0.c1023 op=remove rule
key="number2" list=4 res=0
Change To: type=CONFIG_CHANGE msg=audit(1244666690.117:31): auid=0 ses=1
subj=unconfined_u:unconfined_r:auditctl_t:s0-s0:c0.c1023 op="remove rule"
key="number2" list=4 res=0
Signed-off-by: Eric Paris <eparis@redhat.com>
audit_get_nd() is only used by audit_watch and could be more cleanly
implemented by having the audit watch functions call it when needed rather
than making the generic audit rule parsing code deal with those objects.
Signed-off-by: Eric Paris <eparis@redhat.com>
In preparation for converting audit to use fsnotify instead of inotify we
seperate the inode watching code into it's own file. This is similar to
how the audit tree watching code is already seperated into audit_tree.c
Signed-off-by: Eric Paris <eparis@redhat.com>
audit_receive_skb is hard to clearly parse what it is doing to the netlink
message. Clean the function up so it is easy and clear to see what is going
on.
Signed-off-by: Eric Paris <eparis@redhat.com>
The audit handling of netlink messages is all over the place. Clean things
up, use predetermined macros, generally make it more readable.
Signed-off-by: Eric Paris <eparis@redhat.com>
audit_update_watch() runs all of the rules for a given watch and duplicates
them, attaches a new watch to them, and then when it finishes that process
and has called free on all of the old rules (ok maybe still inside the rcu
grace period) it proceeds to use the last element from list_for_each_entry_safe()
as if it were a krule rather than being the audit_watch which was anchoring
the list to output a message about audit rules changing.
This patch unfies the audit message from two different places into a helper
function and calls it from the correct location in audit_update_rules(). We
will now get an audit message about the config changing for each rule (with
each rules filterkey) rather than the previous garbage.
Signed-off-by: Eric Paris <eparis@redhat.com>
The audit execve record splitting code estimates the length of the message
generated. But it forgot to include the "" that wrap each string in its
estimation. This means that execve messages with lots of tiny (1-2 byte)
arguments could still cause records greater than 8k to be emitted. Simply
fix the estimate.
Signed-off-by: Eric Paris <eparis@redhat.com>
When an audit watch is added to a parent the temporary watch inside the
original krule from userspace is freed. Yet the original watch is used after
the real watch was created in audit_add_rules()
Signed-off-by: Eric Paris <eparis@redhat.com>
We don't need to add usage counts for swcounter and attr usage
models for inherited counters since the parent counter will
always have one, which suffices to generate the needed output.
This avoids up to 3 global atomic increments per inherited
counter.
LKML-Reference: <new-submission>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Teach perf_counter_alloc() about inheritance so that we can
optimize the inherit path in the next patch.
Remove the child_counter->atrr.inherit = 1 line because the
only way to get there is if parent_counter->attr.inherit == 1
and we copy the attrs.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Similar to tracepoints, use an enable variable to reduce
overhead when unused.
Only look for a counter of a particular event type when we know
there is at least one in the system.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
SLAB uses get/put_online_cpus() which use a mutex which is itself only
initialized when cpu_hotplug_init() is called. Currently we hang suring
boot in SLAB due to doing that too late.
Reported by James Bottomley and Sachin Sant (and possibly others).
Debugged by Benjamin Herrenschmidt.
This just removes the dynamic initialization of the data structures, and
replaces it with a static one, avoiding this dependency entirely, and
removing one unnecessary special initcall.
Tested-by: Sachin Sant <sachinp@in.ibm.com>
Tested-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
genirq, irq.h: Fix kernel-doc warnings
genirq: fix comment to say IRQ_WAKE_THREAD
* 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (49 commits)
perfcounter: Handle some IO return values
perf_counter: Push perf_sample_data through the swcounter code
perf_counter tools: Define and use our own u64, s64 etc. definitions
perf_counter: Close race in perf_lock_task_context()
perf_counter, x86: Improve interactions with fast-gup
perf_counter: Simplify and fix task migration counting
perf_counter tools: Add a data file header
perf_counter: Update userspace callchain sampling uses
perf_counter: Make callchain samples extensible
perf report: Filter to parent set by default
perf_counter tools: Handle lost events
perf_counter: Add event overlow handling
fs: Provide empty .set_page_dirty() aop for anon inodes
perf_counter: tools: Makefile tweaks for 64-bit powerpc
perf_counter: powerpc: Add processor back-end for MPC7450 family
perf_counter: powerpc: Make powerpc perf_counter code safe for 32-bit kernels
perf_counter: powerpc: Change how processor-specific back-ends get selected
perf_counter: powerpc: Use unsigned long for register and constraint values
perf_counter: powerpc: Enable use of software counters on 32-bit powerpc
perf_counter tools: Add and use isprint()
...
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Fix out of scope variable access in sched_slice()
sched: Hide runqueues from direct refer at source code level
sched: Remove unneeded __ref tag
sched, x86: Fix cpufreq + sched_clock() TSC scaling
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits)
tracing/urgent: warn in case of ftrace_start_up inbalance
tracing/urgent: fix unbalanced ftrace_start_up
function-graph: add stack frame test
function-graph: disable when both x86_32 and optimize for size are configured
ring-buffer: have benchmark test print to trace buffer
ring-buffer: do not grab locks in nmi
ring-buffer: add locks around rb_per_cpu_empty
ring-buffer: check for less than two in size allocation
ring-buffer: remove useless compile check for buffer_page size
ring-buffer: remove useless warn on check
ring-buffer: use BUF_PAGE_HDR_SIZE in calculating index
tracing: update sample event documentation
tracing/filters: fix race between filter setting and module unload
tracing/filters: free filter_string in destroy_preds()
ring-buffer: use commit counters for commit pointer accounting
ring-buffer: remove unused variable
ring-buffer: have benchmark test handle discarded events
ring-buffer: prevent adding write in discarded area
tracing/filters: strloc should be unsigned short
tracing/filters: operand can be negative
...
Fix up kmemcheck-induced conflict in kernel/trace/ring_buffer.c manually
Push the perf_sample_data further outwards to the swcounter interface,
to abstract it away some more.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Prevent from further ftrace_start_up inbalances so that we avoid
future nop patching omissions with dynamic ftrace.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Perfcounter reports the following stats for a wide system
profiling:
#
# (2364 samples)
#
# Overhead Symbol
# ........ ......
#
15.40% [k] mwait_idle_with_hints
8.29% [k] read_hpet
5.75% [k] ftrace_caller
3.60% [k] ftrace_call
[...]
This snapshot has been taken while neither the function tracer nor
the function graph tracer was running.
With dynamic ftrace, such results show a wrong ftrace behaviour
because all calls to ftrace_caller or ftrace_graph_caller (the patched
calls to mcount) are supposed to be patched into nop if none of those
tracers are running.
The problem occurs after the first run of the function tracer. Once we
launch it a second time, the callsites will never be nopped back,
unless you set custom filters.
For example it happens during the self tests at boot time.
The function tracer selftest runs, and then the dynamic tracing is
tested too. After that, the callsites are left un-nopped.
This is because the reset callback of the function tracer tries to
unregister two ftrace callbacks in once: the common function tracer
and the function tracer with stack backtrace, regardless of which
one is currently in use.
It then creates an unbalance on ftrace_start_up value which is expected
to be zero when the last ftrace callback is unregistered. When it
reaches zero, the FTRACE_DISABLE_CALLS is set on the next ftrace
command, triggering the patching into nop. But since it becomes
unbalanced, ie becomes lower than zero, if the kernel functions
are patched again (as in every further function tracer runs), they
won't ever be nopped back.
Note that ftrace_call and ftrace_graph_call are still patched back
to ftrace_stub in the off case, but not the callers of ftrace_call
and ftrace_graph_caller. It means that the tracing is well deactivated
but we waste a useless call into every kernel function.
This patch just unregisters the right ftrace_ops for the function
tracer on its reset callback and ignores the other one which is
not registered, fixing the unbalance. The problem also happens
is .30
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: stable@kernel.org
The bug is ancient.
If we trace the sub-thread of our natural child and this sub-thread exits,
we update parent->signal->cxxx fields. But we should not do this until
the whole thread-group exits, otherwise we account this thread (and all
other live threads) twice.
Add the task_detached() check. No need to check thread_group_empty(),
wait_consider_task()->delay_group_leader() already did this.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Vitaly Mayatskikh <vmayatsk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
perf_lock_task_context() is buggy because it can return a dead
context.
the RCU read lock in perf_lock_task_context() only guarantees
the memory won't get freed, it doesn't guarantee the object is
valid (in our case refcount > 0).
Therefore we can return a locked object that can get freed the
moment we release the rcu read lock.
perf_pin_task_context() then increases the refcount and does an
unlock on freed memory.
That increased refcount will cause a double free, in case it
started out with 0.
Ammend this by including the get_ctx() functionality in
perf_lock_task_context() (all users already did this later
anyway), and return a NULL context when the found one is
already dead.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The task migrations counter was causing rare and hard to decypher
memory corruptions under load. After a day of debugging and bisection
we found that the problem was introduced with:
3f731ca: perf_counter: Fix cpu migration counter
Turning them off fixes the crashes. Incidentally, the whole
perf_counter_task_migration() logic can be done simpler as well,
by injecting a proper sw-counter event.
This cleanup also fixed the crashes. The precise failure mode is
not completely clear yet, but we are clearly not unhappy about
having a fix ;-)
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In case gcc does something funny with the stack frames, or the return
from function code, we would like to detect that.
An arch may implement passing of a variable that is unique to the
function and can be saved on entering a function and can be tested
when exiting the function. Usually the frame pointer can be used for
this purpose.
This patch also implements this for x86. Where it passes in the stack
frame of the parent function, and will test that frame on exit.
There was a case in x86_32 with optimize for size (-Os) where, for a
few functions, gcc would align the stack frame and place a copy of the
return address into it. The function graph tracer modified the copy and
not the actual return address. On return from the funtion, it did not go
to the tracer hook, but returned to the parent. This broke the function
graph tracer, because the return of the parent (where gcc did not do
this funky manipulation) returned to the location that the child function
was suppose to. This caused strange kernel crashes.
This test detected the problem and pointed out where the issue was.
This modifies the parameters of one of the functions that the arch
specific code calls, so it includes changes to arch code to accommodate
the new prototype.
Note, I notice that the parsic arch implements its own push_return_trace.
This is now a generic function and the ftrace_push_return_trace should be
used instead. This patch does not touch that code.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
On x86_32, when optimize for size is set, gcc may align the frame pointer
and make a copy of the the return address inside the stack frame.
The return address that is located in the stack frame may not be
the one used to return to the calling function. This will break the
function graph tracer.
The function graph tracer replaces the return address with a jump to a hook
function that can trace the exit of the function. If it only replaces
a copy, then the hook will not be called when the function returns.
Worse yet, when the parent function returns, the function graph tracer
will return back to the location of the child function which will
easily crash the kernel with weird results.
To see the problem, when i386 is compiled with -Os we get:
c106be03: 57 push %edi
c106be04: 8d 7c 24 08 lea 0x8(%esp),%edi
c106be08: 83 e4 e0 and $0xffffffe0,%esp
c106be0b: ff 77 fc pushl 0xfffffffc(%edi)
c106be0e: 55 push %ebp
c106be0f: 89 e5 mov %esp,%ebp
c106be11: 57 push %edi
c106be12: 56 push %esi
c106be13: 53 push %ebx
c106be14: 81 ec 8c 00 00 00 sub $0x8c,%esp
c106be1a: e8 f5 57 fb ff call c1021614 <mcount>
When it is compiled with -O2 instead we get:
c10896f0: 55 push %ebp
c10896f1: 89 e5 mov %esp,%ebp
c10896f3: 83 ec 28 sub $0x28,%esp
c10896f6: 89 5d f4 mov %ebx,0xfffffff4(%ebp)
c10896f9: 89 75 f8 mov %esi,0xfffffff8(%ebp)
c10896fc: 89 7d fc mov %edi,0xfffffffc(%ebp)
c10896ff: e8 d0 08 fa ff call c1029fd4 <mcount>
The compile with -Os will align the stack pointer then set up the
frame pointer (%ebp), and it copies the return address back into
the stack frame. The change to the return address in mcount is done
to the copy and not the real place holder of the return address.
Then compile with -O2 sets up the frame pointer first, this makes
the change to the return address by mcount affect where the function
will jump on exit.
Reported-by: Jake Edge <jake@lwn.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Enable gcov profiling of the entire kernel on x86_64. Required changes
include disabling profiling for:
* arch/kernel/acpi/realmode and arch/kernel/boot/compressed:
not linked to main kernel
* arch/vdso, arch/kernel/vsyscall_64 and arch/kernel/hpet:
profiling causes segfaults during boot (incompatible context)
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Enable the use of GCC's coverage testing tool gcov [1] with the Linux
kernel. gcov may be useful for:
* debugging (has this code been reached at all?)
* test improvement (how do I change my test to cover these lines?)
* minimizing kernel configurations (do I need this option if the
associated code is never run?)
The profiling patch incorporates the following changes:
* change kbuild to include profiling flags
* provide functions needed by profiling code
* present profiling data as files in debugfs
Note that on some architectures, enabling gcc's profiling option
"-fprofile-arcs" for the entire kernel may trigger compile/link/
run-time problems, some of which are caused by toolchain bugs and
others which require adjustment of architecture code.
For this reason profiling the entire kernel is initially restricted
to those architectures for which it is known to work without changes.
This restriction can be lifted once an architecture has been tested
and found compatible with gcc's profiling. Profiling of single files
or directories is still available on all platforms (see config help
text).
[1] http://gcc.gnu.org/onlinedocs/gcc/Gcov.html
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Call constructors (gcc-generated initcall-like functions) during kernel
start and module load. Constructors are e.g. used for gcov data
initialization.
Disable constructor support for usermode Linux to prevent conflicts with
host glibc.
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
clone_nsproxy() does useless copying of old nsproxy -- every pointer will
be rewritten to new ns or to old ns. Remove copying, rename
clone_nsproxy(), create_nsproxy() will be used by C/R code to create fresh
nsproxy on restart.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
create_uts_ns() will be used by C/R to create fresh uts_ns.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
copy_pid_ns() is a perfect example of a case where unwinding leads to more
code and makes it less clear. Watch the diffstat.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Reviewed-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
create_pid_namespace() creates everything, but caller has to assign parent
pidns by hand, which is unnatural. At the moment of call new ->level has
to be taken from somewhere and parent pidns is already available.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
find_task_by_pid_type_ns is only used to implement find_task_by_vpid and
find_task_by_pid_ns, but both of them pass PIDTYPE_PID as first argument.
So just fold find_task_by_pid_type_ns into find_task_by_pid_ns and use
find_task_by_pid_ns to implement find_task_by_vpid.
While we're at it also remove the exports for find_task_by_pid_ns and
find_task_by_vpid - we don't have any modular callers left as the only
modular caller of he old pre pid namespace find_task_by_pid (gfs2) was
switched to pid_task which operates on a struct pid pointer instead of a
pid_t. Given the confusion about pid_t values vs namespace that's
generally the better option anyway and I think we're better of restricting
modules to do it that way.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remoce the unused variable 'val' from __do_proc_dointvec()
The integer has been declared and used as 'val = -val' and there is no
reference to it anywhere.
Signed-off-by: Sukanto Ghosh <sukanto.cse.iitb@gmail.com>
Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>
Cc: Sukanto Ghosh <sukanto.cse.iitb@gmail.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that kthread_stop() can be used even if the task has already exited,
we can kill the "wait_to_die:" loop in migration_thread(). But we must
pin rq->migration_thread after creation.
Actually, I don't think CPU_UP_CANCELED or CPU_DEAD should wait for
->migration_thread exit. Perhaps we can simplify this code a bit more.
migration_call() can set ->should_stop and forget about this thread. But
we need a new helper in kthred.c for that.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Vitaliy Gusev <vgusev@openvz.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Based on Eric's patch which in turn was based on my patch.
kthread_stop() has the nasty problems:
- it runs unpredictably long with the global semaphore held.
- it deadlocks if kthread itself does kthread_stop() before it obeys
the kthread_should_stop() request.
- it is not useable if kthread exits on its own, see for example the
ugly "wait_to_die:" hack in migration_thread()
- it is not possible to just tell kthread it should stop, we must always
wait for its exit.
With this patch kthread() allocates all neccesary data (struct kthread) on
its own stack, globals kthread_stop_xxx are deleted. ->vfork_done is used
as a pointer into "struct kthread", this means kthread_stop() can easily
wait for kthread's exit.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Vitaliy Gusev <vgusev@openvz.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We use two completions two create the kernel thread, this is a bit ugly.
kthread() wakes up create_kthread() via ->started, then create_kthread()
wakes up the caller kthread_create() via ->done. But kthread() does not
need to wait for kthread(), it can just return. Instead kthread() itself
can wake up the caller of kthread_create().
Kill kthread_create_info->started, ->done is enough. This improves the
scalability a bit and sijmplifies the code.
The only problem if kernel_thread() fails, in that case create_kthread()
must do complete(&create->done).
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Vitaliy Gusev <vgusev@openvz.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
do_wait:
current->state = TASK_INTERRUPTIBLE;
read_lock(&tasklist_lock);
... search for the task to reap ...
In theory, the ->state changing can leak into the critical section. Since
the child can change its status under read_lock(tasklist) in parallel
(finish_stop/ptrace_stop), we can miss the wakeup if __wake_up_parent()
sees us in TASK_RUNNING state. Add the barrier.
Also, use __set_current_state() to set TASK_RUNNING.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
do_wait() does BUG_ON(tsk->signal != current->signal), this looks like a
raher obsolete check. At least, I don't think do_wait() is the best place
to verify that all threads have the same ->signal. Remove it.
Also, change the code to use while_each_thread().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that we don't pass &retval down to other helpers we can simplify
the code more.
- kill tsk_result, just use retval
- add the "notask" label right after the main loop, and
s/got end/goto notask/ after the fastpath pid check.
This way we don't need to initialize retval before this
check and the code becomes a bit more clean, if this pid
has no attached tasks we should just skip the list search.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce "struct wait_opts" which holds the parameters for misc helpers
in do_wait() pathes.
This adds 13 lines to kernel/exit.c, but saves 256 bytes from .o and imho
makes the code much more readable.
This patch temporary uglifies rusage/siginfo code a little bit, will be
addressed by further cleanups.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
No functional changes, preparation for the next patch.
ptrace_do_wait() adds WUNTRACED to options for wait_task_stopped() which
should always accept the stopped tracee, even if do_wait() was called
without WUNTRACED.
Change wait_task_stopped() to check "ptrace || WUNTRACED" instead. This
makes the code more explicit, and "int options" argument becomes const in
do_wait() pathes.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The forked child can have TIF_SIGPENDING if it was copied from parent's
ti->flags. But this is harmless and actually almost never happens,
because copy_process() can't succeed if signal_pending() == T.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is no reason for thread_group_cputime() in wait_task_zombie(), there
must be no other threads.
This call was previously needed to collect the per-cpu data which we do
not have any longer.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Vitaly Mayatskikh <vmayatsk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change ptrace_getsiginfo/ptrace_setsiginfo to use lock_task_sighand()
without tasklist_lock. Perhaps it makes sense to make a single helper
with "bool rw" argument.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the non-traced sub-thread calls do_notify_parent_cldstop(), we send the
notification to group_leader->real_parent and we report group_leader's
pid.
But, if group_leader is traced we use the wrong ->parent->nsproxy->pid_ns,
the tracer and parent can live in different namespaces. Change the code
to use "parent" instead of tsk->parent.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change wait_task_zombie() to use ->real_parent instead of ->parent. We
could even use current afaics, but ->real_parent is more clean.
We know that the child is not ptrace_reparented() and thus they are equal.
But we should avoid using task_struct->parent, we are going to remove it.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Use rcu_read_lock() instead of tasklist_lock to find/get the task
in ptrace_get_task_struct().
- Make it static, it has no callers outside of ptrace.c.
- The comment doesn't match the reality, this helper does not do
any checks. Beacuse it is really trivial and static I removed the
whole comment.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove the "Nasty, nasty" lock dance in ptrace_attach()/ptrace_traceme() -
from now task_lock() has nothing to do with ptrace at all.
With the recent changes nobody uses task_lock() to serialize with ptrace,
but in fact it was never needed and it was never used consistently.
However ptrace_attach() calls __ptrace_may_access() and needs task_lock()
to pin task->mm for get_dumpable(). But we can call __ptrace_may_access()
before we take tasklist_lock, ->cred_exec_mutex protects us against
do_execve() path which can change creds and MMF_DUMP* flags.
(ugly, but we can't use ptrace_may_access() because it hides the error
code, so we have to take task_lock() and use __ptrace_may_access()).
NOTE: this change assumes that LSM hooks, security_ptrace_may_access() and
security_ptrace_traceme(), can be called without task_lock() held.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ptrace_attach() and ptrace_traceme() are the last functions which look as
if the untraced task can have task->ptrace != 0, this must not be
possible. Change the code to just check ->ptrace != 0 and s/|=/=/ to set
PT_PTRACED.
Also, a couple of trivial whitespace cleanups in ptrace_attach().
And move ptrace_traceme() up near ptrace_attach() to keep them close to
each other.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Add PF_KTHREAD check to prevent attaching to the kernel thread
with a borrowed ->mm.
With or without this change we can race with daemonize() which
can set PF_KTHREAD or clear ->mm after ptrace_attach() does the
check, but this doesn't matter because reparent_to_kthreadd()
does ptrace_unlink().
- Kill "!task->mm" check. We don't really care about ->mm != NULL,
and the task can call exit_mm() right after we drop task_lock().
What we need is to make sure we can't attach after exit_notify(),
check task->exit_state != 0 instead.
Also, move the "already traced" check down for cosmetic reasons.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
No functional changes.
- Nobody except ptrace.c & co should use ptrace flags directly, we have
task_ptrace() for that.
- No need to specially check PT_PTRACED, we must not have other PT_ bits
set without PT_PTRACED. And no need to know this flag exists.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
"Search in the siblings" should use ->real_parent, not ->parent. If the
task is traced then ->parent == tracer, while the task's parent is always
->real_parent.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
allow_signal() checks ->mm == NULL. Not sure why. Perhaps to make sure
current is the kernel thread. But this helper must not be used unless we
are the kernel thread, kill this check.
Also, document the fact that the CLONE_SIGHAND kthread must not use
allow_signal(), unless the caller really wants to change the parent's
->sighand->action as well.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We don't have an interface to reset mem.limit or memsw.limit now.
This patch allows to reset mem.limit or memsw.limit when they are being
set to -1.
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The 'noprefix' option was introduced for backwards-compatibility of
cpuset, but actually it can be used when mounting other subsystems.
This results in possibility of name collision, and now the collision can
really happen, because we have 'stat' file in both memory and cpuacct
subsystem:
# mount -t cgroup -o noprefix,memory,cpuacct xxx /mnt
Cgroup will happily mount the 2 subsystems, but only 'stat' file of memory
subsys can be seen.
We don't want users to use nopreifx, and also want to avoid name
collision, so we change to allow noprefix only if mounting just the cpuset
subsystem.
[akpm@linux-foundation.org: fix shift for cpuset_subsys_id >= 32]
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Statistics for softirq doesn't exist.
It will be helpful like statistics for interrupts.
This patch introduces counting the number of softirq,
which will be exported in /proc/softirqs.
When softirq handler consumes much CPU time,
/proc/stat is like the following.
$ while :; do cat /proc/stat | head -n1 ; sleep 10 ; done
cpu 88 0 408 739665 583 28 2 0 0
cpu 450 0 1090 740970 594 28 1294 0 0
^^^^
softirq
In such a situation,
/proc/softirqs shows us which softirq handler is invoked.
We can see the increase rate of softirqs.
<before>
$ cat /proc/softirqs
CPU0 CPU1 CPU2 CPU3
HI 0 0 0 0
TIMER 462850 462805 462782 462718
NET_TX 0 0 0 365
NET_RX 2472 2 2 40
BLOCK 0 0 381 1164
TASKLET 0 0 0 224
SCHED 462654 462689 462698 462427
RCU 3046 2423 3367 3173
<after>
$ cat /proc/softirqs
CPU0 CPU1 CPU2 CPU3
HI 0 0 0 0
TIMER 463361 465077 465056 464991
NET_TX 53 0 1 365
NET_RX 3757 2 2 40
BLOCK 0 0 398 1170
TASKLET 0 0 0 224
SCHED 463074 464318 464612 463330
RCU 3505 2948 3947 3673
When CPU TIME of softirq is high,
the rates of increase is the following.
TIMER : 220/sec : CPU1-3
NET_TX : 5/sec : CPU0
NET_RX : 120/sec : CPU0
SCHED : 40-200/sec : all CPU
RCU : 45-58/sec : all CPU
The rates of increase in an idle mode is the following.
TIMER : 250/sec
SCHED : 250/sec
RCU : 2/sec
It seems many softirqs for receiving packets and rcu are invoked. This
gives us help for checking system.
Signed-off-by: Keika Kobayashi <kobayashi.kk@ncos.nec.co.jp>
Reviewed-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Masami Hiramatsu