21 Jun, 2018
1 commit
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[ Upstream commit b5bf9a90bbebffba888c9144c5a8a10317b04064 ]
Gaurav reported a perceived problem with TASK_PARKED, which turned out
to be a broken wait-loop pattern in __kthread_parkme(), but the
reported issue can (and does) in fact happen for states that do not do
condition based sleeps.When the 'current->state = TASK_RUNNING' store of a previous
(concurrent) try_to_wake_up() collides with the setting of a 'special'
sleep state, we can loose the sleep state.Normal condition based wait-loops are immune to this problem, but for
sleep states that are not condition based are subject to this problem.There already is a fix for TASK_DEAD. Abstract that and also apply it
to TASK_STOPPED and TASK_TRACED, both of which are also without
condition based wait-loop.Reported-by: Gaurav Kohli
Signed-off-by: Peter Zijlstra (Intel)
Reviewed-by: Oleg Nesterov
Cc: Linus Torvalds
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Signed-off-by: Ingo Molnar
Signed-off-by: Sasha Levin
Signed-off-by: Greg Kroah-Hartman
22 Feb, 2018
1 commit
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commit 75f296d93bcebcfe375884ddac79e30263a31766 upstream.
Convert all allocations that used a NOTRACK flag to stop using it.
Link: http://lkml.kernel.org/r/20171007030159.22241-3-alexander.levin@verizon.com
Signed-off-by: Sasha Levin
Cc: Alexander Potapenko
Cc: Eric W. Biederman
Cc: Michal Hocko
Cc: Pekka Enberg
Cc: Steven Rostedt
Cc: Tim Hansen
Cc: Vegard Nossum
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
Signed-off-by: Greg Kroah-Hartman
10 Jan, 2018
3 commits
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commit 426915796ccaf9c2bd9bb06dc5702225957bc2e5 upstream.
complete_signal() checks SIGNAL_UNKILLABLE before it starts to destroy
the thread group, today this is wrong in many ways.If nothing else, fatal_signal_pending() should always imply that the
whole thread group (except ->group_exit_task if it is not NULL) is
killed, this check breaks the rule.After the previous changes we can rely on sig_task_ignored();
sig_fatal(sig) && SIGNAL_UNKILLABLE can only be true if we actually want
to kill this task and sig == SIGKILL OR it is traced and debugger can
intercept the signal.This should hopefully fix the problem reported by Dmitry. This
test-casestatic int init(void *arg)
{
for (;;)
pause();
}int main(void)
{
char stack[16 * 1024];for (;;) {
int pid = clone(init, stack + sizeof(stack)/2,
CLONE_NEWPID | SIGCHLD, NULL);
assert(pid > 0);assert(ptrace(PTRACE_ATTACH, pid, 0, 0) == 0);
assert(waitpid(-1, NULL, WSTOPPED) == pid);assert(ptrace(PTRACE_DETACH, pid, 0, SIGSTOP) == 0);
assert(syscall(__NR_tkill, pid, SIGKILL) == 0);
assert(pid == wait(NULL));
}
}triggers the WARN_ON_ONCE(!(task->jobctl & JOBCTL_STOP_PENDING)) in
task_participate_group_stop(). do_signal_stop()->signal_group_exit()
checks SIGNAL_GROUP_EXIT and return false, but task_set_jobctl_pending()
checks fatal_signal_pending() and does not set JOBCTL_STOP_PENDING.And his should fix the minor security problem reported by Kyle,
SECCOMP_RET_TRACE can miss fatal_signal_pending() the same way if the
task is the root of a pid namespace.Link: http://lkml.kernel.org/r/20171103184246.GD21036@redhat.com
Signed-off-by: Oleg Nesterov
Reported-by: Dmitry Vyukov
Reported-by: Kyle Huey
Reviewed-by: Kees Cook
Tested-by: Kyle Huey
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
Signed-off-by: Greg Kroah-Hartman -
commit ac25385089f673560867eb5179228a44ade0cfc1 upstream.
Change sig_task_ignored() to drop the SIG_DFL && !sig_kernel_only()
signals even if force == T. This simplifies the next change and this
matches the same check in get_signal() which will drop these signals
anyway.Link: http://lkml.kernel.org/r/20171103184227.GC21036@redhat.com
Signed-off-by: Oleg Nesterov
Tested-by: Kyle Huey
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
Signed-off-by: Greg Kroah-Hartman -
commit 628c1bcba204052d19b686b5bac149a644cdb72e upstream.
The comment in sig_ignored() says "Tracers may want to know about even
ignored signals" but SIGKILL can not be reported to debugger and it is
just wrong to return 0 in this case: SIGKILL should only kill the
SIGNAL_UNKILLABLE task if it comes from the parent ns.Change sig_ignored() to ignore ->ptrace if sig == SIGKILL and rely on
sig_task_ignored().SISGTOP coming from within the namespace is not really right too but at
least debugger can intercept it, and we can't drop it here because this
will break "gdb -p 1": ptrace_attach() won't work. Perhaps we will add
another ->ptrace check later, we will see.Link: http://lkml.kernel.org/r/20171103184206.GB21036@redhat.com
Signed-off-by: Oleg Nesterov
Tested-by: Kyle Huey
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
Signed-off-by: Greg Kroah-Hartman
02 Nov, 2017
1 commit
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Commit cc731525f26a ("signal: Remove kernel interal si_code magic")
added a check for SIGMET and NSIGEMT being defined. That SIGMET should
in fact be SIGEMT, with SIGEMT being defined in
arch/{alpha,mips,sparc}/include/uapi/asm/signal.hThis was actually pointed out by BenHutchings in a lwn.net comment
here https://lwn.net/Comments/734608/Fixes: cc731525f26a ("signal: Remove kernel interal si_code magic")
Signed-off-by: Andrew Clayton
Signed-off-by: "Eric W. Biederman"
12 Sep, 2017
1 commit
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Pull namespace updates from Eric Biederman:
"Life has been busy and I have not gotten half as much done this round
as I would have liked. I delayed it so that a minor conflict
resolution with the mips tree could spend a little time in linux-next
before I sent this pull request.This includes two long delayed user namespace changes from Kirill
Tkhai. It also includes a very useful change from Serge Hallyn that
allows the security capability attribute to be used inside of user
namespaces. The practical effect of this is people can now untar
tarballs and install rpms in user namespaces. It had been suggested to
generalize this and encode some of the namespace information
information in the xattr name. Upon close inspection that makes the
things that should be hard easy and the things that should be easy
more expensive.Then there is my bugfix/cleanup for signal injection that removes the
magic encoding of the siginfo union member from the kernel internal
si_code. The mips folks reported the case where I had used FPE_FIXME
me is impossible so I have remove FPE_FIXME from mips, while at the
same time including a return statement in that case to keep gcc from
complaining about unitialized variables.I almost finished the work to get make copy_siginfo_to_user a trivial
copy to user. The code is available at:git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git neuter-copy_siginfo_to_user-v3
But I did not have time/energy to get the code posted and reviewed
before the merge window opened.I was able to see that the security excuse for just copying fields
that we know are initialized doesn't work in practice there are buggy
initializations that don't initialize the proper fields in siginfo. So
we still sometimes copy unitialized data to userspace"* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
Introduce v3 namespaced file capabilities
mips/signal: In force_fcr31_sig return in the impossible case
signal: Remove kernel interal si_code magic
fcntl: Don't use ambiguous SIG_POLL si_codes
prctl: Allow local CAP_SYS_ADMIN changing exe_file
security: Use user_namespace::level to avoid redundant iterations in cap_capable()
userns,pidns: Verify the userns for new pid namespaces
signal/testing: Don't look for __SI_FAULT in userspace
signal/mips: Document a conflict with SI_USER with SIGFPE
signal/sparc: Document a conflict with SI_USER with SIGFPE
signal/ia64: Document a conflict with SI_USER with SIGFPE
signal/alpha: Document a conflict with SI_USER for SIGTRAP
19 Aug, 2017
1 commit
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When forcing a signal, SIGNAL_UNKILLABLE is removed to prevent recursive
faults, but this is undesirable when tracing. For example, debugging an
init process (whether global or namespace), hitting a breakpoint and
SIGTRAP will force SIGTRAP and then remove SIGNAL_UNKILLABLE.
Everything continues fine, but then once debugging has finished, the
init process is left killable which is unlikely what the user expects,
resulting in either an accidentally killed init or an init that stops
reaping zombies.Link: http://lkml.kernel.org/r/20170815112806.10728-1-jamie.iles@oracle.com
Signed-off-by: Jamie Iles
Acked-by: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Aug, 2017
1 commit
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The latest change of compat_sys_sigpending in commit 8f13621abced
("sigpending(): move compat to native") has broken it in two ways.First, it tries to write 4 bytes more than userspace expects:
sizeof(old_sigset_t) == sizeof(long) == 8 instead of
sizeof(compat_old_sigset_t) == sizeof(u32) == 4.Second, on big endian architectures these bytes are being written in the
wrong order.This bug was found by strace test suite.
Reported-by: Anatoly Pugachev
Inspired-by: Eugene Syromyatnikov
Fixes: 8f13621abced ("sigpending(): move compat to native")
Signed-off-by: Dmitry V. Levin
Acked-by: Al Viro
Signed-off-by: Linus Torvalds
25 Jul, 2017
1 commit
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struct siginfo is a union and the kernel since 2.4 has been hiding a union
tag in the high 16bits of si_code using the values:
__SI_KILL
__SI_TIMER
__SI_POLL
__SI_FAULT
__SI_CHLD
__SI_RT
__SI_MESGQ
__SI_SYSWhile this looks plausible on the surface, in practice this situation has
not worked well.- Injected positive signals are not copied to user space properly
unless they have these magic high bits set.- Injected positive signals are not reported properly by signalfd
unless they have these magic high bits set.- These kernel internal values leaked to userspace via ptrace_peek_siginfo
- It was possible to inject these kernel internal values and cause the
the kernel to misbehave.- Kernel developers got confused and expected these kernel internal values
in userspace in kernel self tests.- Kernel developers got confused and set si_code to __SI_FAULT which
is SI_USER in userspace which causes userspace to think an ordinary user
sent the signal and that it was not kernel generated.- The values make it impossible to reorganize the code to transform
siginfo_copy_to_user into a plain copy_to_user. As si_code must
be massaged before being passed to userspace.So remove these kernel internal si codes and make the kernel code simpler
and more maintainable.To replace these kernel internal magic si_codes introduce the helper
function siginfo_layout, that takes a signal number and an si_code and
computes which union member of siginfo is being used. Have
siginfo_layout return an enumeration so that gcc will have enough
information to warn if a switch statement does not handle all of union
members.A couple of architectures have a messed up ABI that defines signal
specific duplications of SI_USER which causes more special cases in
siginfo_layout than I would like. The good news is only problem
architectures pay the cost.Update all of the code that used the previous magic __SI_ values to
use the new SIL_ values and to call siginfo_layout to get those
values. Escept where not all of the cases are handled remove the
defaults in the switch statements so that if a new case is missed in
the future the lack will show up at compile time.Modify the code that copies siginfo si_code to userspace to just copy
the value and not cast si_code to a short first. The high bits are no
longer used to hold a magic union member.Fixup the siginfo header files to stop including the __SI_ values in
their constants and for the headers that were missing it to properly
update the number of si_codes for each signal type.The fixes to copy_siginfo_from_user32 implementations has the
interesting property that several of them perviously should never have
worked as the __SI_ values they depended up where kernel internal.
With that dependency gone those implementations should work much
better.The idea of not passing the __SI_ values out to userspace and then
not reinserting them has been tested with criu and criu worked without
changes.Ref: 2.4.0-test1
Signed-off-by: "Eric W. Biederman"
11 Jul, 2017
1 commit
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When running kill(72057458746458112, 0) in userspace I hit the following
issue.UBSAN: Undefined behaviour in kernel/signal.c:1462:11
negation of -2147483648 cannot be represented in type 'int':
CPU: 226 PID: 9849 Comm: test Tainted: G B ---- ------- 3.10.0-327.53.58.70.x86_64_ubsan+ #116
Hardware name: Huawei Technologies Co., Ltd. RH8100 V3/BC61PBIA, BIOS BLHSV028 11/11/2014
Call Trace:
dump_stack+0x19/0x1b
ubsan_epilogue+0xd/0x50
__ubsan_handle_negate_overflow+0x109/0x14e
SYSC_kill+0x43e/0x4d0
SyS_kill+0xe/0x10
system_call_fastpath+0x16/0x1bAdd code to avoid the UBSAN detection.
[akpm@linux-foundation.org: tweak comment]
Link: http://lkml.kernel.org/r/1496670008-59084-1-git-send-email-zhongjiang@huawei.com
Signed-off-by: zhongjiang
Cc: Oleg Nesterov
Cc: Michal Hocko
Cc: Vlastimil Babka
Cc: Xishi Qiu
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Jul, 2017
1 commit
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Pull misc compat stuff updates from Al Viro:
"This part is basically untangling various compat stuff. Compat
syscalls moved to their native counterparts, getting rid of quite a
bit of double-copying and/or set_fs() uses. A lot of field-by-field
copyin/copyout killed off.- kernel/compat.c is much closer to containing just the
copyin/copyout of compat structs. Not all compat syscalls are gone
from it yet, but it's getting there.- ipc/compat_mq.c killed off completely.
- block/compat_ioctl.c cleaned up; floppy compat ioctls moved to
drivers/block/floppy.c where they belong. Yes, there are several
drivers that implement some of the same ioctls. Some are m68k and
one is 32bit-only pmac. drivers/block/floppy.c is the only one in
that bunch that can be built on biarch"* 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
mqueue: move compat syscalls to native ones
usbdevfs: get rid of field-by-field copyin
compat_hdio_ioctl: get rid of set_fs()
take floppy compat ioctls to sodding floppy.c
ipmi: get rid of field-by-field __get_user()
ipmi: get COMPAT_IPMICTL_RECEIVE_MSG in sync with the native one
rt_sigtimedwait(): move compat to native
select: switch compat_{get,put}_fd_set() to compat_{get,put}_bitmap()
put_compat_rusage(): switch to copy_to_user()
sigpending(): move compat to native
getrlimit()/setrlimit(): move compat to native
times(2): move compat to native
compat_{get,put}_bitmap(): use unsafe_{get,put}_user()
fb_get_fscreeninfo(): don't bother with do_fb_ioctl()
do_sigaltstack(): lift copying to/from userland into callers
take compat_sys_old_getrlimit() to native syscall
trim __ARCH_WANT_SYS_OLD_GETRLIMIT
04 Jul, 2017
2 commits
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Pull timer updates from Thomas Gleixner:
"A rather large update for timers/timekeeping:- compat syscall consolidation (Al Viro)
- Posix timer consolidation (Christoph Helwig / Thomas Gleixner)
- Cleanup of the device tree based initialization for clockevents and
clocksources (Daniel Lezcano)- Consolidation of the FTTMR010 clocksource/event driver (Linus
Walleij)- The usual set of small fixes and updates all over the place"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (93 commits)
timers: Make the cpu base lock raw
clocksource/drivers/mips-gic-timer: Fix an error code in 'gic_clocksource_of_init()'
clocksource/drivers/fsl_ftm_timer: Unmap region obtained by of_iomap
clocksource/drivers/tcb_clksrc: Make IO endian agnostic
clocksource/drivers/sun4i: Switch to the timer-of common init
clocksource/drivers/timer-of: Fix invalid iomap check
Revert "ktime: Simplify ktime_compare implementation"
clocksource/drivers: Fix uninitialized variable use in timer_of_init
kselftests: timers: Add test for frequency step
kselftests: timers: Fix inconsistency-check to not ignore first timestamp
time: Add warning about imminent deprecation of CONFIG_GENERIC_TIME_VSYSCALL_OLD
time: Clean up CLOCK_MONOTONIC_RAW time handling
posix-cpu-timers: Make timespec to nsec conversion safe
itimer: Make timeval to nsec conversion range limited
timers: Fix parameter description of try_to_del_timer_sync()
ktime: Simplify ktime_compare implementation
clocksource/drivers/fttmr010: Factor out clock read code
clocksource/drivers/fttmr010: Implement delay timer
clocksource/drivers: Add timer-of common init routine
clocksource/drivers/tcb_clksrc: Save timer context on suspend/resume
... -
Pull m68k updates from Geert Uytterhoeven:
- NuBus improvements and cleanups
- defconfig updates
- Fix debugger syscall restart interactions, leading to the global
removal of ptrace_signal_deliver()* tag 'm68k-for-v4.13-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
m68k: Remove ptrace_signal_deliver
m68k/defconfig: Update defconfigs for v4.12-rc1
nubus: Fix pointer validation
nubus: Remove slot zero probe
20 Jun, 2017
1 commit
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This fixes debugger syscall restart interactions. A debugger that
modifies the tracee's program counter is expected to set the orig_d0
pseudo register to -1, to disable a possible syscall restart.This removes the last user of the ptrace_signal_deliver hook in the ptrace
signal handling, so remove that as well.Signed-off-by: Andreas Schwab
Signed-off-by: Geert Uytterhoeven
18 Jun, 2017
1 commit
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Thomas Gleixner wrote:
> The CRIU support added a 'feature' which allows a user space task to send
> arbitrary (kernel) signals to itself. The changelog says:
>
> The kernel prevents sending of siginfo with positive si_code, because
> these codes are reserved for kernel. I think we can allow a task to
> send such a siginfo to itself. This operation should not be dangerous.
>
> Quite contrary to that claim, it turns out that it is outright dangerous
> for signals with info->si_code == SI_TIMER. The following code sequence in
> a user space task allows to crash the kernel:
>
> id = timer_create(CLOCK_XXX, ..... signo = SIGX);
> timer_set(id, ....);
> info->si_signo = SIGX;
> info->si_code = SI_TIMER:
> info->_sifields._timer._tid = id;
> info->_sifields._timer._sys_private = 2;
> rt_[tg]sigqueueinfo(..., SIGX, info);
> sigemptyset(&sigset);
> sigaddset(&sigset, SIGX);
> rt_sigtimedwait(sigset, info);
>
> For timers based on CLOCK_PROCESS_CPUTIME_ID, CLOCK_THREAD_CPUTIME_ID this
> results in a kernel crash because sigwait() dequeues the signal and the
> dequeue code observes:
>
> info->si_code == SI_TIMER && info->_sifields._timer._sys_private != 0
>
> which triggers the following callchain:
>
> do_schedule_next_timer() -> posix_cpu_timer_schedule() -> arm_timer()
>
> arm_timer() executes a list_add() on the timer, which is already armed via
> the timer_set() syscall. That's a double list add which corrupts the posix
> cpu timer list. As a consequence the kernel crashes on the next operation
> touching the posix cpu timer list.
>
> Posix clocks which are internally implemented based on hrtimers are not
> affected by this because hrtimer_start() can handle already armed timers
> nicely, but it's a reliable way to trigger the WARN_ON() in
> hrtimer_forward(), which complains about calling that function on an
> already armed timer.This problem has existed since the posix timer code was merged into
2.5.63. A few releases earlier in 2.5.60 ptrace gained the ability to
inject not just a signal (which linux has supported since 1.0) but the
full siginfo of a signal.The core problem is that the code will reschedule in response to
signals getting dequeued not just for signals the timers sent but
for other signals that happen to a si_code of SI_TIMER.Avoid this confusion by testing to see if the queued signal was
preallocated as all timer signals are preallocated, and so far
only the timer code preallocates signals.Move the check for if a timer needs to be rescheduled up into
collect_signal where the preallocation check must be performed,
and pass the result back to dequeue_signal where the code reschedules
timers. This makes it clear why the code cares about preallocated
timers.Cc: stable@vger.kernel.org
Reported-by: Thomas Gleixner
History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Reference: 66dd34ad31e5 ("signal: allow to send any siginfo to itself")
Reference: 1669ce53e2ff ("Add PTRACE_GETSIGINFO and PTRACE_SETSIGINFO")
Fixes: db8b50ba75f2 ("[PATCH] POSIX clocks & timers")
Signed-off-by: "Eric W. Biederman"
10 Jun, 2017
2 commits
-
Signed-off-by: Al Viro
-
... and kill set_fs() use
Signed-off-by: Al Viro
04 Jun, 2017
2 commits
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That function is a misnomer. Rename it with a proper prefix to
posixtimer_rearm().Signed-off-by: Thomas Gleixner
Cc: Peter Zijlstra
Cc: John Stultz
Link: http://lkml.kernel.org/r/20170530211656.811362578@linutronix.de -
Having it in asm-generic/siginfo.h doesn't make any sense as it is in no way
architecture specific. Move it to posix-timers.h instead.Signed-off-by: Christoph Hellwig
Signed-off-by: Thomas Gleixner
Cc: linux-arch@vger.kernel.org
Cc: Fenghua Yu
Cc: Tony Luck
Cc: linux-ia64@vger.kernel.org
Cc: Arnd Bergmann
Cc: sparclinux@vger.kernel.org
Cc: "David S. Miller"
Link: http://lkml.kernel.org/r/20170603190102.28866-4-hch@lst.de
28 May, 2017
1 commit
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Signed-off-by: Al Viro
11 May, 2017
1 commit
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Pull RCU updates from Ingo Molnar:
"The main changes are:- Debloat RCU headers
- Parallelize SRCU callback handling (plus overlapping patches)
- Improve the performance of Tree SRCU on a CPU-hotplug stress test
- Documentation updates
- Miscellaneous fixes"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (74 commits)
rcu: Open-code the rcu_cblist_n_lazy_cbs() function
rcu: Open-code the rcu_cblist_n_cbs() function
rcu: Open-code the rcu_cblist_empty() function
rcu: Separately compile large rcu_segcblist functions
srcu: Debloat the header
srcu: Adjust default auto-expediting holdoff
srcu: Specify auto-expedite holdoff time
srcu: Expedite first synchronize_srcu() when idle
srcu: Expedited grace periods with reduced memory contention
srcu: Make rcutorture writer stalls print SRCU GP state
srcu: Exact tracking of srcu_data structures containing callbacks
srcu: Make SRCU be built by default
srcu: Fix Kconfig botch when SRCU not selected
rcu: Make non-preemptive schedule be Tasks RCU quiescent state
srcu: Expedite srcu_schedule_cbs_snp() callback invocation
srcu: Parallelize callback handling
kvm: Move srcu_struct fields to end of struct kvm
rcu: Fix typo in PER_RCU_NODE_PERIOD header comment
rcu: Use true/false in assignment to bool
rcu: Use bool value directly
...
22 Apr, 2017
1 commit
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There are no users outside of signal.c so make the function static so
the compiler and other developers have that information.Signed-off-by: "Eric W. Biederman"
19 Apr, 2017
1 commit
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A group of Linux kernel hackers reported chasing a bug that resulted
from their assumption that SLAB_DESTROY_BY_RCU provided an existence
guarantee, that is, that no block from such a slab would be reallocated
during an RCU read-side critical section. Of course, that is not the
case. Instead, SLAB_DESTROY_BY_RCU only prevents freeing of an entire
slab of blocks.However, there is a phrase for this, namely "type safety". This commit
therefore renames SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU in order
to avoid future instances of this sort of confusion.Signed-off-by: Paul E. McKenney
Cc: Christoph Lameter
Cc: Pekka Enberg
Cc: David Rientjes
Cc: Joonsoo Kim
Cc: Andrew Morton
Cc:
Acked-by: Johannes Weiner
Acked-by: Vlastimil Babka
[ paulmck: Add comments mentioning the old name, as requested by Eric
Dumazet, in order to help people familiar with the old name find
the new one. ]
Acked-by: David Rientjes
02 Mar, 2017
7 commits
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…linux/sched/cputime.h>
Introduce a trivial, mostly empty <linux/sched/cputime.h> header
to prepare for the moving of cputime functionality out of sched.h.Update all code that relies on these facilities.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org> -
Update code that relied on sched.h including various MM types for them.
This will allow us to remove the include from .
Acked-by: Linus Torvalds
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar -
We are going to split out of , which
will have to be picked up from other headers and a couple of .c files.Create a trivial placeholder file that just
maps to to make this patch obviously correct and
bisectable.Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar -
We are going to split out of , which
will have to be picked up from other headers and a couple of .c files.Create a trivial placeholder file that just
maps to to make this patch obviously correct and
bisectable.Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar -
We are going to split out of , which
will have to be picked up from other headers and a couple of .c files.Create a trivial placeholder file that just
maps to to make this patch obviously correct and
bisectable.Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar -
We are going to split out of , which
will have to be picked up from other headers and a couple of .c files.Create a trivial placeholder file that just
maps to to make this patch obviously correct and
bisectable.Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar -
threadgroup_change_begin()/end() is a pointless wrapper around
cgroup_threadgroup_change_begin()/end(), minus a might_sleep()
in the !CONFIG_CGROUPS=y case.Remove the wrappery, move the might_sleep() (the down_read()
already has a might_sleep() check).This debloats a bit and simplifies this API.
Update all call sites.
No change in functionality.
Acked-by: Linus Torvalds
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar
28 Feb, 2017
1 commit
-
Currently SS_AUTODISARM is not supported in compatibility mode, but does
not return -EINVAL either. This makes dosemu built with -m32 on x86_64
to crash. Also the kernel's sigaltstack selftest fails if compiled with
-m32.This patch adds the needed support.
Link: http://lkml.kernel.org/r/20170205101213.8163-2-stsp@list.ru
Signed-off-by: Stas Sergeev
Cc: Milosz Tanski
Cc: Andy Lutomirski
Cc: Al Viro
Cc: Arnd Bergmann
Cc: Thomas Gleixner
Cc: Ingo Molnar
Cc: Oleg Nesterov
Cc: Nicolas Pitre
Cc: Waiman Long
Cc: Dave Hansen
Cc: Dmitry Safonov
Cc: Wang Xiaoqiang
Cc: Oleg Nesterov
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Feb, 2017
3 commits
-
Use the new nsec based cputime accessors as part of the whole cputime
conversion from cputime_t to nsecs.Signed-off-by: Frederic Weisbecker
Cc: Benjamin Herrenschmidt
Cc: Fenghua Yu
Cc: Heiko Carstens
Cc: Linus Torvalds
Cc: Martin Schwidefsky
Cc: Michael Ellerman
Cc: Paul Mackerras
Cc: Peter Zijlstra
Cc: Rik van Riel
Cc: Stanislaw Gruszka
Cc: Thomas Gleixner
Cc: Tony Luck
Cc: Wanpeng Li
Link: http://lkml.kernel.org/r/1485832191-26889-16-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar -
Now that most cputime readers use the transition API which return the
task cputime in old style cputime_t, we can safely store the cputime in
nsecs. This will eventually make cputime statistics less opaque and more
granular. Back and forth convertions between cputime_t and nsecs in order
to deal with cputime_t random granularity won't be needed anymore.Signed-off-by: Frederic Weisbecker
Cc: Benjamin Herrenschmidt
Cc: Fenghua Yu
Cc: Heiko Carstens
Cc: Linus Torvalds
Cc: Martin Schwidefsky
Cc: Michael Ellerman
Cc: Paul Mackerras
Cc: Peter Zijlstra
Cc: Rik van Riel
Cc: Stanislaw Gruszka
Cc: Thomas Gleixner
Cc: Tony Luck
Cc: Wanpeng Li
Link: http://lkml.kernel.org/r/1485832191-26889-8-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar -
This API returns a task's cputime in cputime_t in order to ease the
conversion of cputime internals to use nsecs units instead. Blindly
converting all cputime readers to use this API now will later let us
convert more smoothly and step by step all these places to use the
new nsec based cputime.Signed-off-by: Frederic Weisbecker
Cc: Benjamin Herrenschmidt
Cc: Fenghua Yu
Cc: Heiko Carstens
Cc: Linus Torvalds
Cc: Martin Schwidefsky
Cc: Michael Ellerman
Cc: Paul Mackerras
Cc: Peter Zijlstra
Cc: Rik van Riel
Cc: Stanislaw Gruszka
Cc: Thomas Gleixner
Cc: Tony Luck
Cc: Wanpeng Li
Link: http://lkml.kernel.org/r/1485832191-26889-7-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar
11 Jan, 2017
1 commit
-
Since commit 00cd5c37afd5 ("ptrace: permit ptracing of /sbin/init") we
can now trace init processes. init is initially protected with
SIGNAL_UNKILLABLE which will prevent fatal signals such as SIGSTOP, but
there are a number of paths during tracing where SIGNAL_UNKILLABLE can
be implicitly cleared.This can result in init becoming stoppable/killable after tracing. For
example, running:while true; do kill -STOP 1; done &
strace -p 1and then stopping strace and the kill loop will result in init being
left in state TASK_STOPPED. Sending SIGCONT to init will resume it, but
init will now respond to future SIGSTOP signals rather than ignoring
them.Make sure that when setting SIGNAL_STOP_CONTINUED/SIGNAL_STOP_STOPPED
that we don't clear SIGNAL_UNKILLABLE.Link: http://lkml.kernel.org/r/20170104122017.25047-1-jamie.iles@oracle.com
Signed-off-by: Jamie Iles
Acked-by: Oleg Nesterov
Cc: Alexander Viro
Cc: Ingo Molnar
Cc: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
26 Dec, 2016
1 commit
-
ktime is a union because the initial implementation stored the time in
scalar nanoseconds on 64 bit machine and in a endianess optimized timespec
variant for 32bit machines. The Y2038 cleanup removed the timespec variant
and switched everything to scalar nanoseconds. The union remained, but
become completely pointless.Get rid of the union and just keep ktime_t as simple typedef of type s64.
The conversion was done with coccinelle and some manual mopping up.
Signed-off-by: Thomas Gleixner
Cc: Peter Zijlstra
25 Dec, 2016
1 commit
-
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*'
sed -i -e "s!$PATT!#include !" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)to do the replacement at the end of the merge window.
Requested-by: Al Viro
Signed-off-by: Linus Torvalds
15 Dec, 2016
1 commit
-
When running certain database workload on a high-end system with many
CPUs, it was found that spinlock contention in the sigprocmask syscalls
became a significant portion of the overall CPU cycles as shown below.9.30% 9.30% 905387 dataserver /proc/kcore 0x7fff8163f4d2
[k] _raw_spin_lock_irq
|
---_raw_spin_lock_irq
|
|--99.34%-- __set_current_blocked
| sigprocmask
| sys_rt_sigprocmask
| system_call_fastpath
| |
| |--50.63%-- __swapcontext
| | |
| | |--99.91%-- upsleepgeneric
| |
| |--49.36%-- __setcontext
| | ktskRunLooking further into the swapcontext function in glibc, it was found that
the function always call sigprocmask() without checking if there are
changes in the signal mask.A check was added to the __set_current_blocked() function to avoid taking
the sighand->siglock spinlock if there is no change in the signal mask.
This will prevent unneeded spinlock contention when many threads are
trying to call sigprocmask().With this patch applied, the spinlock contention in sigprocmask() was
gone.Link: http://lkml.kernel.org/r/1474979209-11867-1-git-send-email-Waiman.Long@hpe.com
Signed-off-by: Waiman Long
Acked-by: Oleg Nesterov
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: Stas Sergeev
Cc: Scott J Norton
Cc: Douglas Hatch
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
16 Nov, 2016
1 commit
-
Some embedded systems have no use for them. This removes about
25KB from the kernel binary size when configured out.Corresponding syscalls are routed to a stub logging the attempt to
use those syscalls which should be enough of a clue if they were
disabled without proper consideration. They are: timer_create,
timer_gettime: timer_getoverrun, timer_settime, timer_delete,
clock_adjtime, setitimer, getitimer, alarm.The clock_settime, clock_gettime, clock_getres and clock_nanosleep
syscalls are replaced by simple wrappers compatible with CLOCK_REALTIME,
CLOCK_MONOTONIC and CLOCK_BOOTTIME only which should cover the vast
majority of use cases with very little code.Signed-off-by: Nicolas Pitre
Acked-by: Richard Cochran
Acked-by: Thomas Gleixner
Acked-by: John Stultz
Reviewed-by: Josh Triplett
Cc: Paul Bolle
Cc: linux-kbuild@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: Michal Marek
Cc: Edward Cree
Link: http://lkml.kernel.org/r/1478841010-28605-7-git-send-email-nicolas.pitre@linaro.org
Signed-off-by: Thomas Gleixner
