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 <schwab@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
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 <tglx@linutronix.de>
History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Reference: 66dd34ad31 ("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" <ebiederm@xmission.com>
That function is a misnomer. Rename it with a proper prefix to
posixtimer_rearm().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.811362578@linutronix.de
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 <linux/rcu_segcblist.h> 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
...
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" <ebiederm@xmission.com>
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 <paulmck@linux.vnet.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <linux-mm@kvack.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
[ 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 <rientjes@google.com>
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 <linux/mm_types.h> include from <linux/sched.h>.
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>
We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/task_stack.h> file that just
maps to <linux/sched.h> 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 <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>
We are going to split <linux/sched/task.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/task.h> file that just
maps to <linux/sched.h> 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 <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>
We are going to split <linux/sched/debug.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/debug.h> file that just
maps to <linux/sched.h> 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 <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>
We are going to split <linux/sched/user.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/user.h> file that just
maps to <linux/sched.h> 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 <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>
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 <linux/sched.h> a bit and simplifies this API.
Update all call sites.
No change in functionality.
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>
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 <stsp@users.sourceforge.net>
Cc: Milosz Tanski <milosz@adfin.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Waiman Long <Waiman.Long@hpe.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Wang Xiaoqiang <wangxq10@lzu.edu.cn>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the new nsec based cputime accessors as part of the whole cputime
conversion from cputime_t to nsecs.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Link: http://lkml.kernel.org/r/1485832191-26889-16-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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 <fweisbec@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Link: http://lkml.kernel.org/r/1485832191-26889-8-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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 <fweisbec@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Link: http://lkml.kernel.org/r/1485832191-26889-7-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Since commit 00cd5c37af ("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 1
and 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 <jamie.iles@oracle.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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
| | ktskRun
Looking 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 <Waiman.Long@hpe.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Stas Sergeev <stsp@list.ru>
Cc: Scott J Norton <scott.norton@hpe.com>
Cc: Douglas Hatch <doug.hatch@hpe.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 <nico@linaro.org>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: linux-kbuild@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: Michal Marek <mmarek@suse.com>
Cc: Edward Cree <ecree@solarflare.com>
Link: http://lkml.kernel.org/r/1478841010-28605-7-git-send-email-nicolas.pitre@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Introduce new flags that defines which ABI to use on creating sigframe.
Those flags kernel will set according to sigaction syscall ABI,
which set handler for the signal being delivered.
So that will drop the dependency on TIF_IA32/TIF_X32 flags on signal deliver.
Those flags will be used only under CONFIG_COMPAT.
Similar way ARM uses sa_flags to differ in which mode deliver signal
for 26-bit applications (look at SA_THIRYTWO).
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: 0x7f454c46@gmail.com
Cc: oleg@redhat.com
Cc: linux-mm@kvack.org
Cc: gorcunov@openvz.org
Cc: xemul@virtuozzo.com
Link: http://lkml.kernel.org/r/20160905133308.28234-7-dsafonov@virtuozzo.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We've converted most timeout related syscalls to hrtimers, but
sigtimedwait() did not get this treatment.
Convert it so we get a reasonable accuracy and remove the
user space exposure to the timer wheel properties.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Chris Mason <clm@fb.com>
Cc: Cyril Hrubis <chrubis@suse.cz>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160704094341.787164909@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Use pr_<level> instead of printk(KERN_<LEVEL> ).
Signed-off-by: Wang Xiaoqiang <wangxq10@lzu.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sigaltstack()'s reported previous state uses a somewhat odd
convention, but the concept of flag bits is new, and we can do the
flag bits sensibly. Specifically, let's just report them directly.
This will allow saving and restoring the sigaltstack state using
sigaltstack() to work correctly.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Amanieu d'Antras <amanieu@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Stas Sergeev <stsp@list.ru>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: linux-api@vger.kernel.org
Link: http://lkml.kernel.org/r/94b291ec9fd47741a9264851e316e158ded0b00d.1462296606.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch implements the SS_AUTODISARM flag that can be OR-ed with
SS_ONSTACK when forming ss_flags.
When this flag is set, sigaltstack will be disabled when entering
the signal handler; more precisely, after saving sas to uc_stack.
When leaving the signal handler, the sigaltstack is restored by
uc_stack.
When this flag is used, it is safe to switch from sighandler with
swapcontext(). Without this flag, the subsequent signal will corrupt
the state of the switched-away sighandler.
To detect the support of this functionality, one can do:
err = sigaltstack(SS_DISABLE | SS_AUTODISARM);
if (err && errno == EINVAL)
unsupported();
Signed-off-by: Stas Sergeev <stsp@list.ru>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Amanieu d'Antras <amanieu@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Jason Low <jason.low2@hp.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <pmoore@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: linux-api@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1460665206-13646-4-git-send-email-stsp@list.ru
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch adds SS_FLAG_BITS - the mask that splits sigaltstack
mode values and bit-flags. Since there is no bit-flags yet, the
mask is defined to 0. The flags are added by subsequent patches.
With every new flag, the mask should have the appropriate bit cleared.
This makes sure if some flag is tried on a kernel that doesn't
support it, the -EINVAL error will be returned, because such a
flag will be treated as an invalid mode rather than the bit-flag.
That way the existence of the particular features can be probed
at run-time.
This change was suggested by Andy Lutomirski:
https://lkml.org/lkml/2016/3/6/158
Signed-off-by: Stas Sergeev <stsp@list.ru>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Amanieu d'Antras <amanieu@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: linux-api@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1460665206-13646-3-git-send-email-stsp@list.ru
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The value of __ARCH_SI_PREAMBLE_SIZE defines the size (including
padding) of the part of the struct siginfo that is before the union, and
it is then used to calculate the needed padding (SI_PAD_SIZE) to make
the size of struct siginfo equal to 128 (SI_MAX_SIZE) bytes.
Depending on the target architecture and word width it equals to either
3 or 4 times sizeof int.
Since the very beginning we had __ARCH_SI_PREAMBLE_SIZE wrong on the
parisc architecture for the 64bit kernel build. It's even more
frustrating, because it can easily be checked at compile time if the
value was defined correctly.
This patch adds such a check for the correctness of
__ARCH_SI_PREAMBLE_SIZE in the hope that it will prevent existing and
future architectures from running into the same problem.
I refrained from replacing __ARCH_SI_PREAMBLE_SIZE by offsetof() in
copy_siginfo() in include/asm-generic/siginfo.h, because a) it doesn't
make any difference and b) it's used in the Documentation/kmemcheck.txt
example.
I ran this patch through the 0-DAY kernel test infrastructure and only
the parisc architecture triggered as expected. That means that this
patch should be OK for all major architectures.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A protection key fault is very similar to any other access error.
There must be a VMA, etc... We even want to take the same action
(SIGSEGV) that we do with a normal access fault.
However, we do need to let userspace know that something is
different. We do this the same way what we did with SEGV_BNDERR
with Memory Protection eXtensions (MPX): define a new SEGV code:
SEGV_PKUERR.
We add a siginfo field: si_pkey that reveals to userspace which
protection key was set on the PTE that we faulted on. There is
no other easy way for userspace to figure this out. They could
parse smaps but that would be a bit cruel.
We share space with in siginfo with _addr_bnd. #BR faults from
MPX are completely separate from page faults (#PF) that trigger
from protection key violations, so we never need both at the same
time.
Note that _pkey is a 64-bit value. The current hardware only
supports 4-bit protection keys. We do this because there is
_plenty_ of space in _sigfault and it is possible that future
processors would support more than 4 bits of protection keys.
The x86 code to actually fill in the siginfo is in the next
patch.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Amanieu d'Antras <amanieu@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210212.3A9B83AC@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
A random wakeup can get us out of sigsuspend() without TIF_SIGPENDING
being set.
Avoid that by making sure we were signaled, like sys_pause() does.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sigsuspend() is nowhere used except in signal.c itself, so we can mark it
static do not pollute the global namespace.
But this patch is more than a boring cleanup patch, it fixes a real issue
on UserModeLinux. UML has a special console driver to display ttys using
xterm, or other terminal emulators, on the host side. Vegard reported
that sometimes UML is unable to spawn a xterm and he's facing the
following warning:
WARNING: CPU: 0 PID: 908 at include/linux/thread_info.h:128 sigsuspend+0xab/0xc0()
It turned out that this warning makes absolutely no sense as the UML
xterm code calls sigsuspend() on the host side, at least it tries. But
as the kernel itself offers a sigsuspend() symbol the linker choose this
one instead of the glibc wrapper. Interestingly this code used to work
since ever but always blocked signals on the wrong side. Some recent
kernel change made the WARN_ON() trigger and uncovered the bug.
It is a wonderful example of how much works by chance on computers. :-)
Fixes: 68f3f16d9a ("new helper: sigsuspend()")
Signed-off-by: Richard Weinberger <richard@nod.at>
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Tested-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org> [3.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
task_will_free_mem() is wrong in many ways, and in particular the
SIGNAL_GROUP_COREDUMP check is not reliable: a task can participate in the
coredumping without SIGNAL_GROUP_COREDUMP bit set.
change zap_threads() paths to always set SIGNAL_GROUP_COREDUMP even if
other CLONE_VM processes can't react to SIGKILL. Fortunately, at least
oom-kill case if fine; it kills all tasks sharing the same mm, so it
should also kill the process which actually dumps the core.
The change in prepare_signal() is not strictly necessary, it just ensures
that the patch does not bring another subtle behavioural change. But it
reminds us that this SIGNAL_GROUP_EXIT/COREDUMP case needs more changes.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Kyle Walker <kwalker@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Stanislav Kozina <skozina@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is hardly possible to enumerate all problems with block_all_signals()
and unblock_all_signals(). Just for example,
1. block_all_signals(SIGSTOP/etc) simply can't help if the caller is
multithreaded. Another thread can dequeue the signal and force the
group stop.
2. Even is the caller is single-threaded, it will "stop" anyway. It
will not sleep, but it will spin in kernel space until SIGCONT or
SIGKILL.
And a lot more. In short, this interface doesn't work at all, at least
the last 10+ years.
Daniel said:
Yeah the only times I played around with the DRM_LOCK stuff was when
old drivers accidentally deadlocked - my impression is that the entire
DRM_LOCK thing was never really tested properly ;-) Hence I'm all for
purging where this leaks out of the drm subsystem.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Dave Airlie <airlied@redhat.com>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This function may copy the si_addr_lsb, si_lower and si_upper fields to
user mode when they haven't been initialized, which can leak kernel
stack data to user mode.
Just checking the value of si_code is insufficient because the same
si_code value is shared between multiple signals. This is solved by
checking the value of si_signo in addition to si_code.
Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This function can leak kernel stack data when the user siginfo_t has a
positive si_code value. The top 16 bits of si_code descibe which fields
in the siginfo_t union are active, but they are treated inconsistently
between copy_siginfo_from_user32, copy_siginfo_to_user32 and
copy_siginfo_to_user.
copy_siginfo_from_user32 is called from rt_sigqueueinfo and
rt_tgsigqueueinfo in which the user has full control overthe top 16 bits
of si_code.
This fixes the following information leaks:
x86: 8 bytes leaked when sending a signal from a 32-bit process to
itself. This leak grows to 16 bytes if the process uses x32.
(si_code = __SI_CHLD)
x86: 100 bytes leaked when sending a signal from a 32-bit process to
a 64-bit process. (si_code = -1)
sparc: 4 bytes leaked when sending a signal from a 32-bit process to a
64-bit process. (si_code = any)
parsic and s390 have similar bugs, but they are not vulnerable because
rt_[tg]sigqueueinfo have checks that prevent sending a positive si_code
to a different process. These bugs are also fixed for consistency.
Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull security subsystem updates from James Morris:
"The main change in this kernel is Casey's generalized LSM stacking
work, which removes the hard-coding of Capabilities and Yama stacking,
allowing multiple arbitrary "small" LSMs to be stacked with a default
monolithic module (e.g. SELinux, Smack, AppArmor).
See
https://lwn.net/Articles/636056/
This will allow smaller, simpler LSMs to be incorporated into the
mainline kernel and arbitrarily stacked by users. Also, this is a
useful cleanup of the LSM code in its own right"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (38 commits)
tpm, tpm_crb: fix le64_to_cpu conversions in crb_acpi_add()
vTPM: set virtual device before passing to ibmvtpm_reset_crq
tpm_ibmvtpm: remove unneccessary message level.
ima: update builtin policies
ima: extend "mask" policy matching support
ima: add support for new "euid" policy condition
ima: fix ima_show_template_data_ascii()
Smack: freeing an error pointer in smk_write_revoke_subj()
selinux: fix setting of security labels on NFS
selinux: Remove unused permission definitions
selinux: enable genfscon labeling for sysfs and pstore files
selinux: enable per-file labeling for debugfs files.
selinux: update netlink socket classes
signals: don't abuse __flush_signals() in selinux_bprm_committed_creds()
selinux: Print 'sclass' as string when unrecognized netlink message occurs
Smack: allow multiple labels in onlycap
Smack: fix seq operations in smackfs
ima: pass iint to ima_add_violation()
ima: wrap event related data to the new ima_event_data structure
integrity: add validity checks for 'path' parameter
...
selinux_bprm_committed_creds()->__flush_signals() is not right, we
shouldn't clear TIF_SIGPENDING unconditionally. There can be other
reasons for signal_pending(): freezing(), JOBCTL_PENDING_MASK, and
potentially more.
Also change this code to check fatal_signal_pending() rather than
SIGNAL_GROUP_EXIT, it looks a bit better.
Now we can kill __flush_signals() before it finds another buggy user.
Note: this code looks racy, we can flush a signal which was sent after
the task SID has been updated.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
c56fb6564dcd ("Fix a misaligned load inside ptrace_attach()") makes
jobctl an "unsigned long". It makes sense to have the masks applied
to it match that type. This is currently just a cosmetic change, but
it will prevent the mask from being unexpectedly truncated if we ever
end up with masks with more bits.
One instance of "signr" is an int, but I left this alone because the
mask ensures that it will never overflow.
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bobby.prani@gmail.com
Cc: oleg@redhat.com
Cc: paulmck@linux.vnet.ibm.com
Cc: richard@nod.at
Cc: vdavydov@parallels.com
Link: http://lkml.kernel.org/r/1430453997-32459-4-git-send-email-palmer@dabbelt.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Sending SI_TKILL from rt_[tg]sigqueueinfo was deprecated, so now we issue
a warning on the first attempt of doing it. We use WARN_ON_ONCE, which is
not informative and, what is worse, taints the kernel, making the trinity
syscall fuzzer complain false-positively from time to time.
It does not look like we need this warning at all, because the behaviour
changed quite a long time ago (2.6.39), and if an application relies on
the old API, it gets EPERM anyway and can issue a warning by itself.
So let us zap the warning in kernel.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Call __set_current_state() instead of assigning the new state directly.
These interfaces also aid CONFIG_DEBUG_ATOMIC_SLEEP environments, keeping
track of who changed the state.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If an attacker can cause a controlled kernel stack overflow, overwriting
the restart block is a very juicy exploit target. This is because the
restart_block is held in the same memory allocation as the kernel stack.
Moving the restart block to struct task_struct prevents this exploit by
making the restart_block harder to locate.
Note that there are other fields in thread_info that are also easy
targets, at least on some architectures.
It's also a decent simplification, since the restart code is more or less
identical on all architectures.
[james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Miller <davem@davemloft.net>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 MPX support from Thomas Gleixner:
"This enables support for x86 MPX.
MPX is a new debug feature for bound checking in user space. It
requires kernel support to handle the bound tables and decode the
bound violating instruction in the trap handler"
* 'x86-mpx-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
asm-generic: Remove asm-generic arch_bprm_mm_init()
mm: Make arch_unmap()/bprm_mm_init() available to all architectures
x86: Cleanly separate use of asm-generic/mm_hooks.h
x86 mpx: Change return type of get_reg_offset()
fs: Do not include mpx.h in exec.c
x86, mpx: Add documentation on Intel MPX
x86, mpx: Cleanup unused bound tables
x86, mpx: On-demand kernel allocation of bounds tables
x86, mpx: Decode MPX instruction to get bound violation information
x86, mpx: Add MPX-specific mmap interface
x86, mpx: Introduce VM_MPX to indicate that a VMA is MPX specific
x86, mpx: Add MPX to disabled features
ia64: Sync struct siginfo with general version
mips: Sync struct siginfo with general version
mpx: Extend siginfo structure to include bound violation information
x86, mpx: Rename cfg_reg_u and status_reg
x86: mpx: Give bndX registers actual names
x86: Remove arbitrary instruction size limit in instruction decoder
This patch adds new fields about bound violation into siginfo
structure. si_lower and si_upper are respectively lower bound
and upper bound when bound violation is caused.
Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-mm@kvack.org
Cc: linux-mips@linux-mips.org
Cc: Dave Hansen <dave@sr71.net>
Link: http://lkml.kernel.org/r/20141114151819.1908C900@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
__cleanup_sighand() frees sighand without RCU grace period. This is
correct but this looks "obviously buggy" and constantly confuses the
readers, add the comments to explain how this works.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
The kill_pid_info() can potentially loop indefinitely if tasks are created
and deleted sufficiently quickly, and if this happens, this function
will remain in a single RCU read-side critical section indefinitely.
This commit therefore exits the RCU read-side critical section on each
pass through the loop. Because a race must happen to retry the loop,
this should have no performance impact in the common case.
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
Pull arch signal handling cleanup from Richard Weinberger:
"This patch series moves all remaining archs to the get_signal(),
signal_setup_done() and sigsp() functions.
Currently these archs use open coded variants of the said functions.
Further, unused parameters get removed from get_signal_to_deliver(),
tracehook_signal_handler() and signal_delivered().
At the end of the day we save around 500 lines of code."
* 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc: (43 commits)
powerpc: Use sigsp()
openrisc: Use sigsp()
mn10300: Use sigsp()
mips: Use sigsp()
microblaze: Use sigsp()
metag: Use sigsp()
m68k: Use sigsp()
m32r: Use sigsp()
hexagon: Use sigsp()
frv: Use sigsp()
cris: Use sigsp()
c6x: Use sigsp()
blackfin: Use sigsp()
avr32: Use sigsp()
arm64: Use sigsp()
arc: Use sigsp()
sas_ss_flags: Remove nested ternary if
Rip out get_signal_to_deliver()
Clean up signal_delivered()
tracehook_signal_handler: Remove sig, info, ka and regs
...
- Pass a ksignal struct to it
- Remove unused regs parameter
- Make it private as it's nowhere outside of kernel/signal.c is used
Signed-off-by: Richard Weinberger <richard@nod.at>
The explicit local_irq_save() in __lock_task_sighand() is needed to avoid
a potential deadlock condition, as noted in a841796f11 (signal:
align __lock_task_sighand() irq disabling and RCU). However, someone
reading the code might be forgiven for concluding that this separate
local_irq_save() was completely unnecessary. This commit therefore adds
a comment referencing the shiny new block comment on rcu_read_unlock().
Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Now that allow_signal() is really trivial we can unify it with
disallow_signal(). Add the new helper, kernel_sigaction(), and
reimplement allow_signal/disallow_signal as a trivial wrappers.
This saves one EXPORT_SYMBOL() and the new helper can have more users.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
disallow_signal() simply sets SIG_IGN, this is not enough and
recalc_sigpending() is simply pointless because in can never change the
state of TIF_SIGPENDING.
If we ignore a signal, we also need to do flush_sigqueue_mask() for the
case when this signal is pending, this way recalc_sigpending() can
actually clear TIF_SIGPENDING and we do not "leak" the allocated
siginfo's.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
allow_signal() does sigdelset(current->blocked) due to historic reason,
previously it could be called by a daemonize()'ed kthread, and
daemonize() played with current->blocked.
Now that daemonize() has gone away we can remove sigdelset() and
recalc_sigpending(). If a user really wants to unblock a signal, it
must use sigprocmask() or set_current_block() explicitely.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move the declaration/definition of allow_signal/disallow_signal to
signal.h/signal.c. The new place is more logical and allows to use the
static helpers in signal.c (see the next changes).
While at it, make them return void and remove the valid_signal() check.
Nobody checks the returned value, and in-kernel users must not pass the
wrong signal number.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The usage of "task_struct *t" and "current" in do_sigaction() looks really
annoying and chaotic. Initially "t" is used as a cached value of current
but not consistently, then it is reused as a loop variable and we have to
use "current" again.
Clean up this mess and also convert the code to use for_each_thread().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
"rm_from_queue_full" looks ugly and misleading, especially now that
rm_from_queue() has gone away. Rename it to flush_sigqueue_mask(), this
matches flush_sigqueue() we already have.
Also remove the obsolete comment which explains the difference with
rm_from_queue() we already killed.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rm_from_queue() doesn't make sense. The only caller, prepare_signal(),
can use rm_from_queue_full() with the same effect.
While at it, change prepare_signal() to use for_each_thread() instead of
do/while_each_thread.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To increase compiler portability there is <linux/compiler.h> which
provides convenience macros for various gcc constructs. Eg: __weak for
__attribute__((weak)). I've replaced all instances of gcc attributes
with the right macro in the kernel subsystem.
Signed-off-by: Gideon Israel Dsouza <gidisrael@gmail.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fix spelling typo in Documentation/DocBook.
It is because .html and .xml files are generated by make htmldocs,
I have to fix a typo within the source files.
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
I found the following pattern that leads in to interesting findings:
grep -r "ret.*|=.*__put_user" *
grep -r "ret.*|=.*__get_user" *
grep -r "ret.*|=.*__copy" *
The __put_user() calls in compat_ioctl.c, ptrace compat, signal compat,
since those appear in compat code, we could probably expect the kernel
addresses not to be reachable in the lower 32-bit range, so I think they
might not be exploitable.
For the "__get_user" cases, I don't think those are exploitable: the worse
that can happen is that the kernel will copy kernel memory into in-kernel
buffers, and will fail immediately afterward.
The alpha csum_partial_copy_from_user() seems to be missing the
access_ok() check entirely. The fix is inspired from x86. This could
lead to information leak on alpha. I also noticed that many architectures
map csum_partial_copy_from_user() to csum_partial_copy_generic(), but I
wonder if the latter is performing the access checks on every
architectures.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Avoid waking up every thread sleeping in a sigtimedwait call during
suspend and resume by calling a freezable blocking call. Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.
This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull networking updates from David Miller:
"Highlights (1721 non-merge commits, this has to be a record of some
sort):
1) Add 'random' mode to team driver, from Jiri Pirko and Eric
Dumazet.
2) Make it so that any driver that supports configuration of multiple
MAC addresses can provide the forwarding database add and del
calls by providing a default implementation and hooking that up if
the driver doesn't have an explicit set of handlers. From Vlad
Yasevich.
3) Support GSO segmentation over tunnels and other encapsulating
devices such as VXLAN, from Pravin B Shelar.
4) Support L2 GRE tunnels in the flow dissector, from Michael Dalton.
5) Implement Tail Loss Probe (TLP) detection in TCP, from Nandita
Dukkipati.
6) In the PHY layer, allow supporting wake-on-lan in situations where
the PHY registers have to be written for it to be configured.
Use it to support wake-on-lan in mv643xx_eth.
From Michael Stapelberg.
7) Significantly improve firewire IPV6 support, from YOSHIFUJI
Hideaki.
8) Allow multiple packets to be sent in a single transmission using
network coding in batman-adv, from Martin Hundebøll.
9) Add support for T5 cxgb4 chips, from Santosh Rastapur.
10) Generalize the VXLAN forwarding tables so that there is more
flexibility in configurating various aspects of the endpoints.
From David Stevens.
11) Support RSS and TSO in hardware over GRE tunnels in bxn2x driver,
from Dmitry Kravkov.
12) Zero copy support in nfnelink_queue, from Eric Dumazet and Pablo
Neira Ayuso.
13) Start adding networking selftests.
14) In situations of overload on the same AF_PACKET fanout socket, or
per-cpu packet receive queue, minimize drop by distributing the
load to other cpus/fanouts. From Willem de Bruijn and Eric
Dumazet.
15) Add support for new payload offset BPF instruction, from Daniel
Borkmann.
16) Convert several drivers over to mdoule_platform_driver(), from
Sachin Kamat.
17) Provide a minimal BPF JIT image disassembler userspace tool, from
Daniel Borkmann.
18) Rewrite F-RTO implementation in TCP to match the final
specification of it in RFC4138 and RFC5682. From Yuchung Cheng.
19) Provide netlink socket diag of netlink sockets ("Yo dawg, I hear
you like netlink, so I implemented netlink dumping of netlink
sockets.") From Andrey Vagin.
20) Remove ugly passing of rtnetlink attributes into rtnl_doit
functions, from Thomas Graf.
21) Allow userspace to be able to see if a configuration change occurs
in the middle of an address or device list dump, from Nicolas
Dichtel.
22) Support RFC3168 ECN protection for ipv6 fragments, from Hannes
Frederic Sowa.
23) Increase accuracy of packet length used by packet scheduler, from
Jason Wang.
24) Beginning set of changes to make ipv4/ipv6 fragment handling more
scalable and less susceptible to overload and locking contention,
from Jesper Dangaard Brouer.
25) Get rid of using non-type-safe NLMSG_* macros and use nlmsg_*()
instead. From Hong Zhiguo.
26) Optimize route usage in IPVS by avoiding reference counting where
possible, from Julian Anastasov.
27) Convert IPVS schedulers to RCU, also from Julian Anastasov.
28) Support cpu fanouts in xt_NFQUEUE netfilter target, from Holger
Eitzenberger.
29) Network namespace support for nf_log, ebt_log, xt_LOG, ipt_ULOG,
nfnetlink_log, and nfnetlink_queue. From Gao feng.
30) Implement RFC3168 ECN protection, from Hannes Frederic Sowa.
31) Support several new r8169 chips, from Hayes Wang.
32) Support tokenized interface identifiers in ipv6, from Daniel
Borkmann.
33) Use usbnet_link_change() helper in USB net driver, from Ming Lei.
34) Add 802.1ad vlan offload support, from Patrick McHardy.
35) Support mmap() based netlink communication, also from Patrick
McHardy.
36) Support HW timestamping in mlx4 driver, from Amir Vadai.
37) Rationalize AF_PACKET packet timestamping when transmitting, from
Willem de Bruijn and Daniel Borkmann.
38) Bring parity to what's provided by /proc/net/packet socket dumping
and the info provided by netlink socket dumping of AF_PACKET
sockets. From Nicolas Dichtel.
39) Fix peeking beyond zero sized SKBs in AF_UNIX, from Benjamin
Poirier"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1722 commits)
filter: fix va_list build error
af_unix: fix a fatal race with bit fields
bnx2x: Prevent memory leak when cnic is absent
bnx2x: correct reading of speed capabilities
net: sctp: attribute printl with __printf for gcc fmt checks
netlink: kconfig: move mmap i/o into netlink kconfig
netpoll: convert mutex into a semaphore
netlink: Fix skb ref counting.
net_sched: act_ipt forward compat with xtables
mlx4_en: fix a build error on 32bit arches
Revert "bnx2x: allow nvram test to run when device is down"
bridge: avoid OOPS if root port not found
drivers: net: cpsw: fix kernel warn on cpsw irq enable
sh_eth: use random MAC address if no valid one supplied
3c509.c: call SET_NETDEV_DEV for all device types (ISA/ISAPnP/EISA)
tg3: fix to append hardware time stamping flags
unix/stream: fix peeking with an offset larger than data in queue
unix/dgram: fix peeking with an offset larger than data in queue
unix/dgram: peek beyond 0-sized skbs
openvswitch: Remove unneeded ovs_netdev_get_ifindex()
...
There are 2 well known and ancient problems with coredump/signals, and a
lot of related bug reports:
- do_coredump() clears TIF_SIGPENDING but of course this can't help
if, say, SIGCHLD comes after that.
In this case the coredump can fail unexpectedly. See for example
wait_for_dump_helper()->signal_pending() check but there are other
reasons.
- At the same time, dumping a huge core on the slow media can take a
lot of time/resources and there is no way to kill the coredumping
task reliably. In particular this is not oom_kill-friendly.
This patch tries to fix the 1st problem, and makes the preparation for the
next changes.
We add the new SIGNAL_GROUP_COREDUMP flag set by zap_threads() to indicate
that this process dumps the core. prepare_signal() checks this flag and
nacks any signal except SIGKILL.
Note that this check tries to be conservative, in the long term we should
probably treat the SIGNAL_GROUP_EXIT case equally but this needs more
discussion. See marc.info/?l=linux-kernel&m=120508897917439
Notes:
- recalc_sigpending() doesn't check SIGNAL_GROUP_COREDUMP.
The patch assumes that dump_write/etc paths should never
call it, but we can change it as well.
- There is another source of TIF_SIGPENDING, freezer. This
will be addressed separately.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Neil Horman <nhorman@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
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>
Conflicts:
drivers/net/ethernet/emulex/benet/be_main.c
drivers/net/ethernet/intel/igb/igb_main.c
drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c
include/net/scm.h
net/batman-adv/routing.c
net/ipv4/tcp_input.c
The e{uid,gid} --> {uid,gid} credentials fix conflicted with the
cleanup in net-next to now pass cred structs around.
The be2net driver had a bug fix in 'net' that overlapped with the VLAN
interface changes by Patrick McHardy in net-next.
An IGB conflict existed because in 'net' the build_skb() support was
reverted, and in 'net-next' there was a comment style fix within that
code.
Several batman-adv conflicts were resolved by making sure that all
calls to batadv_is_my_mac() are changed to have a new bat_priv first
argument.
Eric Dumazet's TS ECR fix in TCP in 'net' conflicted with the F-RTO
rewrite in 'net-next', mostly overlapping changes.
Thanks to Stephen Rothwell and Antonio Quartulli for help with several
of these merge resolutions.
Signed-off-by: David S. Miller <davem@davemloft.net>
This fixes a kernel memory contents leak via the tkill and tgkill syscalls
for compat processes.
This is visible in the siginfo_t->_sifields._rt.si_sigval.sival_ptr field
when handling signals delivered from tkill.
The place of the infoleak:
int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
{
...
put_user_ex(ptr_to_compat(from->si_ptr), &to->si_ptr);
...
}
Signed-off-by: Emese Revfy <re.emese@gmail.com>
Reviewed-by: PaX Team <pageexec@freemail.hu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Process connector can now also detect coredumping events.
Main aim of patch is get notified at start of coredumping, instead of
having to wait for it to finish and then being notified through EXIT
event.
Could be used for instance by process-managers that want to get
notified as soon as possible about process failures, and not
necessarily beeing notified after coredump, which could be in the
order of minutes depending on size of coredump, piping and so on.
Signed-off-by: Jesper Derehag <jderehag@hotmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
__ARCH_HAS_SA_RESTORER is the preferred conditional for use in 3.9 and
later kernels, per Kees.
Cc: Emese Revfy <re.emese@gmail.com>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: Julien Tinnes <jln@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When the new signal handlers are set up, the location of sa_restorer is
not cleared, leaking a parent process's address space location to
children. This allows for a potential bypass of the parent's ASLR by
examining the sa_restorer value returned when calling sigaction().
Based on what should be considered "secret" about addresses, it only
matters across the exec not the fork (since the VMAs haven't changed
until the exec). But since exec sets SIG_DFL and keeps sa_restorer,
this is where it should be fixed.
Given the few uses of sa_restorer, a "set" function was not written
since this would be the only use. Instead, we use
__ARCH_HAS_SA_RESTORER, as already done in other places.
Example of the leak before applying this patch:
$ cat /proc/$$/maps
...
7fb9f3083000-7fb9f3238000 r-xp 00000000 fd:01 404469 .../libc-2.15.so
...
$ ./leak
...
7f278bc74000-7f278be29000 r-xp 00000000 fd:01 404469 .../libc-2.15.so
...
1 0 (nil) 0x7fb9f30b94a0
2 4000000 (nil) 0x7f278bcaa4a0
3 4000000 (nil) 0x7f278bcaa4a0
4 0 (nil) 0x7fb9f30b94a0
...
[akpm@linux-foundation.org: use SA_RESTORER for backportability]
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Emese Revfy <re.emese@gmail.com>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: Julien Tinnes <jln@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix new kernel-doc warnings in kernel/signal.c:
Warning(kernel/signal.c:2689): No description found for parameter 'uset'
Warning(kernel/signal.c:2689): Excess function parameter 'set' description in 'sys_rt_sigpending'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull sigprocmask compat fix from Al Viro:
"generic compat_sys_rt_sigprocmask() had a very dumb braino; I'd spent
quite a while staring at the offending commit before finally managing
to spot the idiocy ;-/"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
fix compat_sys_rt_sigprocmask()
Converting bitmask to 32bit granularity is fine, but we'd better
_do_ something with the result. Such as "copy it to userland"...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Several printk's were missing KERN_INFO and KERN_CONT flags. In
addition, a printk that was outside a #if/#endif should have been
inside, which would result in stray blank line on non-x86 boxes.
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The idea is simple. We need to get the siginfo for each signal on
checkpointing dump, and then return it back on restore.
The first problem is that the kernel doesn't report complete siginfos to
userspace. In a signal handler the kernel strips SI_CODE from siginfo.
When a siginfo is received from signalfd, it has a different format with
fixed sizes of fields. The interface of signalfd was extended. If a
signalfd is created with the flag SFD_RAW, it returns siginfo in a raw
format.
rt_sigqueueinfo looks suitable for restoring signals, but it can't send
siginfo with a positive si_code, because these codes are reserved for
the kernel. In the real world each person has right to do anything with
himself, so I think a process should able to send any siginfo to itself.
This patch:
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.
This functionality is required for restoring signals in
checkpoint/restart.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull signal handling cleanups from Al Viro:
"This is the first pile; another one will come a bit later and will
contain SYSCALL_DEFINE-related patches.
- a bunch of signal-related syscalls (both native and compat)
unified.
- a bunch of compat syscalls switched to COMPAT_SYSCALL_DEFINE
(fixing several potential problems with missing argument
validation, while we are at it)
- a lot of now-pointless wrappers killed
- a couple of architectures (cris and hexagon) forgot to save
altstack settings into sigframe, even though they used the
(uninitialized) values in sigreturn; fixed.
- microblaze fixes for delivery of multiple signals arriving at once
- saner set of helpers for signal delivery introduced, several
architectures switched to using those."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (143 commits)
x86: convert to ksignal
sparc: convert to ksignal
arm: switch to struct ksignal * passing
alpha: pass k_sigaction and siginfo_t using ksignal pointer
burying unused conditionals
make do_sigaltstack() static
arm64: switch to generic old sigaction() (compat-only)
arm64: switch to generic compat rt_sigaction()
arm64: switch compat to generic old sigsuspend
arm64: switch to generic compat rt_sigqueueinfo()
arm64: switch to generic compat rt_sigpending()
arm64: switch to generic compat rt_sigprocmask()
arm64: switch to generic sigaltstack
sparc: switch to generic old sigsuspend
sparc: COMPAT_SYSCALL_DEFINE does all sign-extension as well as SYSCALL_DEFINE
sparc: kill sign-extending wrappers for native syscalls
kill sparc32_open()
sparc: switch to use of generic old sigaction
sparc: switch sys_compat_rt_sigaction() to COMPAT_SYSCALL_DEFINE
mips: switch to generic sys_fork() and sys_clone()
...
__ARCH_WANT_SYS_RT_SIGACTION,
__ARCH_WANT_SYS_RT_SIGSUSPEND,
__ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND,
__ARCH_WANT_COMPAT_SYS_SCHED_RR_GET_INTERVAL - not used anymore
CONFIG_GENERIC_{SIGALTSTACK,COMPAT_RT_SIG{ACTION,QUEUEINFO,PENDING,PROCMASK}} -
can be assumed always set.
Typical cputime stats infrastructure relies on the timer tick and
its periodic polling on the CPU to account the amount of time
spent by the CPUs and the tasks per high level domains such as
userspace, kernelspace, guest, ...
Now we are preparing to implement full dynticks capability on
Linux for Real Time and HPC users who want full CPU isolation.
This feature requires a cputime accounting that doesn't depend
on the timer tick.
To implement it, this new cputime infrastructure plugs into
kernel/user/guest boundaries to take snapshots of cputime and
flush these to the stats when needed. This performs pretty
much like CONFIG_VIRT_CPU_ACCOUNTING except that context location
and cputime snaphots are synchronized between write and read
side such that the latter can safely retrieve the pending tickless
cputime of a task and add it to its latest cputime snapshot to
return the correct result to the user.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
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Merge tag 'full-dynticks-cputime-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into sched/core
Pull full-dynticks (user-space execution is undisturbed and
receives no timer IRQs) preparation changes that convert the
cputime accounting code to be full-dynticks ready,
from Frederic Weisbecker:
"This implements the cputime accounting on full dynticks CPUs.
Typical cputime stats infrastructure relies on the timer tick and
its periodic polling on the CPU to account the amount of time
spent by the CPUs and the tasks per high level domains such as
userspace, kernelspace, guest, ...
Now we are preparing to implement full dynticks capability on
Linux for Real Time and HPC users who want full CPU isolation.
This feature requires a cputime accounting that doesn't depend
on the timer tick.
To implement it, this new cputime infrastructure plugs into
kernel/user/guest boundaries to take snapshots of cputime and
flush these to the stats when needed. This performs pretty
much like CONFIG_VIRT_CPU_ACCOUNTING except that context location
and cputime snaphots are synchronized between write and read
side such that the latter can safely retrieve the pending tickless
cputime of a task and add it to its latest cputime snapshot to
return the correct result to the user."
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
mips was the last architecture not using the generic variant.
Both native and compat variants switched to generic, which is
made unconditional now.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
usual "call force_sigsegv or signal_delivered" logics. Takes
ksignal instead of separate siginfo/k_sigaction.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Again, protected by a temporary config symbol (GENERIC_COMPAT_RT_SIGACTION);
will be gone by the end of series.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
conditional on GENERIC_COMPAT_RT_SIGQUEUEINFO; by the end of that series
it will become the same thing as COMPAT and conditional will die out.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
conditional on GENERIC_COMPAT_RT_SIGPENDING; by the end of that series
it will become the same thing as COMPAT and conditional will die out.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
conditional on GENERIC_COMPAT_RT_SIGPROCMASK; by the end of that series
it will become the same thing as COMPAT and conditional will die out.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* pull compat version alongside with the native one
* make little-endian compat variant just call the native
* don't bother with separate conditional for compat (both native and
compat are going to become unconditional very soon).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Switch from __ARCH_WANT_SYS_RT_SIGACTION to opposite
(!CONFIG_ODD_RT_SIGACTION); the only two architectures that
need it are alpha and sparc. The reason for use of CONFIG_...
instead of __ARCH_... is that it's needed only kernel-side
and doing it that way avoids a mess with include order on many
architectures.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This is in preparation for the full dynticks feature. While
remotely reading the cputime of a task running in a full
dynticks CPU, we'll need to do some extra-computation. This
way we can account the time it spent tickless in userspace
since its last cputime snapshot.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
putreg() assumes that the tracee is not running and pt_regs_access() can
safely play with its stack. However a killed tracee can return from
ptrace_stop() to the low-level asm code and do RESTORE_REST, this means
that debugger can actually read/modify the kernel stack until the tracee
does SAVE_REST again.
set_task_blockstep() can race with SIGKILL too and in some sense this
race is even worse, the very fact the tracee can be woken up breaks the
logic.
As Linus suggested we can clear TASK_WAKEKILL around the arch_ptrace()
call, this ensures that nobody can ever wakeup the tracee while the
debugger looks at it. Not only this fixes the mentioned problems, we
can do some cleanups/simplifications in arch_ptrace() paths.
Probably ptrace_unfreeze_traced() needs more callers, for example it
makes sense to make the tracee killable for oom-killer before
access_process_vm().
While at it, add the comment into may_ptrace_stop() to explain why
ptrace_stop() still can't rely on SIGKILL and signal_pending_state().
Reported-by: Salman Qazi <sqazi@google.com>
Reported-by: Suleiman Souhlal <suleiman@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cleanup and preparation for the next change.
signal_wake_up(resume => true) is overused. None of ptrace/jctl callers
actually want to wakeup a TASK_WAKEKILL task, but they can't specify the
necessary mask.
Turn signal_wake_up() into signal_wake_up_state(state), reintroduce
signal_wake_up() as a trivial helper, and add ptrace_signal_wake_up()
which adds __TASK_TRACED.
This way ptrace_signal_wake_up() can work "inside" ptrace_request()
even if the tracee doesn't have the TASK_WAKEKILL bit set.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull misc syscall fixes from Al Viro:
- compat syscall fixes (discussed back in December)
- a couple of "make life easier for sigaltstack stuff by reducing
inter-tree dependencies"
- fix up compiler/asmlinkage calling convention disagreement of
sys_clone()
- misc
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
sys_clone() needs asmlinkage_protect
make sure that /linuxrc has std{in,out,err}
x32: fix sigtimedwait
x32: fix waitid()
switch compat_sys_wait4() and compat_sys_waitid() to COMPAT_SYSCALL_DEFINE
switch compat_sys_sigaltstack() to COMPAT_SYSCALL_DEFINE
CONFIG_GENERIC_SIGALTSTACK build breakage with asm-generic/syscalls.h
Ensure that kernel_init_freeable() is not inlined into non __init code
Cleanup. And I think we need more cleanups, in particular
__set_current_blocked() and sigprocmask() should die. Nobody should
ever block SIGKILL or SIGSTOP.
- Change set_current_blocked() to use __set_current_blocked()
- Change sys_sigprocmask() to use set_current_blocked(), this way it
should not worry about SIGKILL/SIGSTOP.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull signal handling cleanups from Al Viro:
"sigaltstack infrastructure + conversion for x86, alpha and um,
COMPAT_SYSCALL_DEFINE infrastructure.
Note that there are several conflicts between "unify
SS_ONSTACK/SS_DISABLE definitions" and UAPI patches in mainline;
resolution is trivial - just remove definitions of SS_ONSTACK and
SS_DISABLED from arch/*/uapi/asm/signal.h; they are all identical and
include/uapi/linux/signal.h contains the unified variant."
Fixed up conflicts as per Al.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
alpha: switch to generic sigaltstack
new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to those
generic compat_sys_sigaltstack()
introduce generic sys_sigaltstack(), switch x86 and um to it
new helper: compat_user_stack_pointer()
new helper: restore_altstack()
unify SS_ONSTACK/SS_DISABLE definitions
new helper: current_user_stack_pointer()
missing user_stack_pointer() instances
Bury the conditionals from kernel_thread/kernel_execve series
COMPAT_SYSCALL_DEFINE: infrastructure
Conditional on CONFIG_GENERIC_SIGALTSTACK; architectures that do not
select it are completely unaffected
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull user namespace changes from Eric Biederman:
"While small this set of changes is very significant with respect to
containers in general and user namespaces in particular. The user
space interface is now complete.
This set of changes adds support for unprivileged users to create user
namespaces and as a user namespace root to create other namespaces.
The tyranny of supporting suid root preventing unprivileged users from
using cool new kernel features is broken.
This set of changes completes the work on setns, adding support for
the pid, user, mount namespaces.
This set of changes includes a bunch of basic pid namespace
cleanups/simplifications. Of particular significance is the rework of
the pid namespace cleanup so it no longer requires sending out
tendrils into all kinds of unexpected cleanup paths for operation. At
least one case of broken error handling is fixed by this cleanup.
The files under /proc/<pid>/ns/ have been converted from regular files
to magic symlinks which prevents incorrect caching by the VFS,
ensuring the files always refer to the namespace the process is
currently using and ensuring that the ptrace_mayaccess permission
checks are always applied.
The files under /proc/<pid>/ns/ have been given stable inode numbers
so it is now possible to see if different processes share the same
namespaces.
Through the David Miller's net tree are changes to relax many of the
permission checks in the networking stack to allowing the user
namespace root to usefully use the networking stack. Similar changes
for the mount namespace and the pid namespace are coming through my
tree.
Two small changes to add user namespace support were commited here adn
in David Miller's -net tree so that I could complete the work on the
/proc/<pid>/ns/ files in this tree.
Work remains to make it safe to build user namespaces and 9p, afs,
ceph, cifs, coda, gfs2, ncpfs, nfs, nfsd, ocfs2, and xfs so the
Kconfig guard remains in place preventing that user namespaces from
being built when any of those filesystems are enabled.
Future design work remains to allow root users outside of the initial
user namespace to mount more than just /proc and /sys."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (38 commits)
proc: Usable inode numbers for the namespace file descriptors.
proc: Fix the namespace inode permission checks.
proc: Generalize proc inode allocation
userns: Allow unprivilged mounts of proc and sysfs
userns: For /proc/self/{uid,gid}_map derive the lower userns from the struct file
procfs: Print task uids and gids in the userns that opened the proc file
userns: Implement unshare of the user namespace
userns: Implent proc namespace operations
userns: Kill task_user_ns
userns: Make create_new_namespaces take a user_ns parameter
userns: Allow unprivileged use of setns.
userns: Allow unprivileged users to create new namespaces
userns: Allow setting a userns mapping to your current uid.
userns: Allow chown and setgid preservation
userns: Allow unprivileged users to create user namespaces.
userns: Ignore suid and sgid on binaries if the uid or gid can not be mapped
userns: fix return value on mntns_install() failure
vfs: Allow unprivileged manipulation of the mount namespace.
vfs: Only support slave subtrees across different user namespaces
vfs: Add a user namespace reference from struct mnt_namespace
...
Pull big execve/kernel_thread/fork unification series from Al Viro:
"All architectures are converted to new model. Quite a bit of that
stuff is actually shared with architecture trees; in such cases it's
literally shared branch pulled by both, not a cherry-pick.
A lot of ugliness and black magic is gone (-3KLoC total in this one):
- kernel_thread()/kernel_execve()/sys_execve() redesign.
We don't do syscalls from kernel anymore for either kernel_thread()
or kernel_execve():
kernel_thread() is essentially clone(2) with callback run before we
return to userland, the callbacks either never return or do
successful do_execve() before returning.
kernel_execve() is a wrapper for do_execve() - it doesn't need to
do transition to user mode anymore.
As a result kernel_thread() and kernel_execve() are
arch-independent now - they live in kernel/fork.c and fs/exec.c
resp. sys_execve() is also in fs/exec.c and it's completely
architecture-independent.
- daemonize() is gone, along with its parts in fs/*.c
- struct pt_regs * is no longer passed to do_fork/copy_process/
copy_thread/do_execve/search_binary_handler/->load_binary/do_coredump.
- sys_fork()/sys_vfork()/sys_clone() unified; some architectures
still need wrappers (ones with callee-saved registers not saved in
pt_regs on syscall entry), but the main part of those suckers is in
kernel/fork.c now."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (113 commits)
do_coredump(): get rid of pt_regs argument
print_fatal_signal(): get rid of pt_regs argument
ptrace_signal(): get rid of unused arguments
get rid of ptrace_signal_deliver() arguments
new helper: signal_pt_regs()
unify default ptrace_signal_deliver
flagday: kill pt_regs argument of do_fork()
death to idle_regs()
don't pass regs to copy_process()
flagday: don't pass regs to copy_thread()
bfin: switch to generic vfork, get rid of pointless wrappers
xtensa: switch to generic clone()
openrisc: switch to use of generic fork and clone
unicore32: switch to generic clone(2)
score: switch to generic fork/vfork/clone
c6x: sanitize copy_thread(), get rid of clone(2) wrapper, switch to generic clone()
take sys_fork/sys_vfork/sys_clone prototypes to linux/syscalls.h
mn10300: switch to generic fork/vfork/clone
h8300: switch to generic fork/vfork/clone
tile: switch to generic clone()
...
Conflicts:
arch/microblaze/include/asm/Kbuild
the first one is equal to signal_pt_regs(), the second is never used
(and always NULL, while we are at it).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The expressions tsk->nsproxy->pid_ns and task_active_pid_ns
aka ns_of_pid(task_pid(tsk)) should have the same number of
cache line misses with the practical difference that
ns_of_pid(task_pid(tsk)) is released later in a processes life.
Furthermore by using task_active_pid_ns it becomes trivial
to write an unshare implementation for the the pid namespace.
So I have used task_active_pid_ns everywhere I can.
In fork since the pid has not yet been attached to the
process I use ns_of_pid, to achieve the same effect.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
try_to_freeze_tasks() and cgroup_freezer rely on scheduler locks
to ensure that a task doing STOPPED/TRACED -> RUNNING transition
can't escape freezing. This mostly works, but ptrace_stop() does
not necessarily call schedule(), it can change task->state back to
RUNNING and check freezing() without any lock/barrier in between.
We could add the necessary barrier, but this patch changes
ptrace_stop() and do_signal_stop() to use freezable_schedule().
This fixes the race, freezer_count() and freezer_should_skip()
carefully avoid the race.
And this simplifies the code, try_to_freeze_tasks/update_if_frozen
no longer need to use task_is_stopped_or_traced() checks with the
non trivial assumptions. We can rely on the mechanism which was
specially designed to mark the sleeping task as "frozen enough".
v2: As Tejun pointed out, we can also change get_signal_to_deliver()
and move try_to_freeze() up before 'relock' label.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This is a preparatory patch for the introduction of NT_SIGINFO elf note.
With this patch we pass "siginfo_t *siginfo" instead of "int signr" to
do_coredump() and put it into coredump_params. It will be used by the
next patch. Most changes are simple s/signr/siginfo->si_signo/.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: "Jonathan M. Foote" <jmfoote@cert.org>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Create a new header file, fs/coredump.h, which contains functions only
used by the new coredump.c. It also moves do_coredump to the
include/linux/coredump.h header file, for consistency.
Signed-off-by: Alex Kelly <alex.page.kelly@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ptrace_notify() and get_signal_to_deliver() do unnecessary things
before task_work_run():
1. smp_mb__after_clear_bit() is not needed, test_and_clear_bit()
implies mb().
2. And we do not need the barrier at all, in this case we only
care about the "synchronous" works added by the task itself.
3. No need to clear TIF_NOTIFY_RESUME, and we should not assume
task_works is the only user of this flag.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20120826191217.GA4238@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Does block_sigmask() + tracehook_signal_handler(); called when
sigframe has been successfully built. All architectures converted
to it; block_sigmask() itself is gone now (merged into this one).
I'm still not too happy with the signature, but that's a separate
story (IMO we need a structure that would contain signal number +
siginfo + k_sigaction, so that get_signal_to_deliver() would fill one,
signal_delivered(), handle_signal() and probably setup...frame() -
take one).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Only 3 out of 63 do not. Renamed the current variant to __set_current_blocked(),
added set_current_blocked() that will exclude unblockable signals, switched
open-coded instances to it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Everyone either defines it in arch thread_info.h or has TIF_RESTORE_SIGMASK
and picks default set_restore_sigmask() in linux/thread_info.h. Kill the
ifdefs, slap #error in linux/thread_info.h to catch breakage when new ones
get merged.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Using task_active_pid_ns is more robust because it works even after we
have called exit_namespaces. This change allows us to have parent
processes that are zombies. Normally a zombie parent processes is crazy
and the last thing you would want to have but in the case of not letting
the init process of a pid namespace be reaped until all of it's children
are dead and reaped a zombie parent process is exactly what we want.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Louis Rilling <louis.rilling@kerlabs.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull user-space probe instrumentation from Ingo Molnar:
"The uprobes code originates from SystemTap and has been used for years
in Fedora and RHEL kernels. This version is much rewritten, reviews
from PeterZ, Oleg and myself shaped the end result.
This tree includes uprobes support in 'perf probe' - but SystemTap
(and other tools) can take advantage of user probe points as well.
Sample usage of uprobes via perf, for example to profile malloc()
calls without modifying user-space binaries.
First boot a new kernel with CONFIG_UPROBE_EVENT=y enabled.
If you don't know which function you want to probe you can pick one
from 'perf top' or can get a list all functions that can be probed
within libc (binaries can be specified as well):
$ perf probe -F -x /lib/libc.so.6
To probe libc's malloc():
$ perf probe -x /lib64/libc.so.6 malloc
Added new event:
probe_libc:malloc (on 0x7eac0)
You can now use it in all perf tools, such as:
perf record -e probe_libc:malloc -aR sleep 1
Make use of it to create a call graph (as the flat profile is going to
look very boring):
$ perf record -e probe_libc:malloc -gR make
[ perf record: Woken up 173 times to write data ]
[ perf record: Captured and wrote 44.190 MB perf.data (~1930712
$ perf report | less
32.03% git libc-2.15.so [.] malloc
|
--- malloc
29.49% cc1 libc-2.15.so [.] malloc
|
--- malloc
|
|--0.95%-- 0x208eb1000000000
|
|--0.63%-- htab_traverse_noresize
11.04% as libc-2.15.so [.] malloc
|
--- malloc
|
7.15% ld libc-2.15.so [.] malloc
|
--- malloc
|
5.07% sh libc-2.15.so [.] malloc
|
--- malloc
|
4.99% python-config libc-2.15.so [.] malloc
|
--- malloc
|
4.54% make libc-2.15.so [.] malloc
|
--- malloc
|
|--7.34%-- glob
| |
| |--93.18%-- 0x41588f
| |
| --6.82%-- glob
| 0x41588f
...
Or:
$ perf report -g flat | less
# Overhead Command Shared Object Symbol
# ........ ............. ............. ..........
#
32.03% git libc-2.15.so [.] malloc
27.19%
malloc
29.49% cc1 libc-2.15.so [.] malloc
24.77%
malloc
11.04% as libc-2.15.so [.] malloc
11.02%
malloc
7.15% ld libc-2.15.so [.] malloc
6.57%
malloc
...
The core uprobes design is fairly straightforward: uprobes probe
points register themselves at (inode:offset) addresses of
libraries/binaries, after which all existing (or new) vmas that map
that address will have a software breakpoint injected at that address.
vmas are COW-ed to preserve original content. The probe points are
kept in an rbtree.
If user-space executes the probed inode:offset instruction address
then an event is generated which can be recovered from the regular
perf event channels and mmap-ed ring-buffer.
Multiple probes at the same address are supported, they create a
dynamic callback list of event consumers.
The basic model is further complicated by the XOL speedup: the
original instruction that is probed is copied (in an architecture
specific fashion) and executed out of line when the probe triggers.
The XOL area is a single vma per process, with a fixed number of
entries (which limits probe execution parallelism).
The API: uprobes are installed/removed via
/sys/kernel/debug/tracing/uprobe_events, the API is integrated to
align with the kprobes interface as much as possible, but is separate
to it.
Injecting a probe point is privileged operation, which can be relaxed
by setting perf_paranoid to -1.
You can use multiple probes as well and mix them with kprobes and
regular PMU events or tracepoints, when instrumenting a task."
Fix up trivial conflicts in mm/memory.c due to previous cleanup of
unmap_single_vma().
* 'perf-uprobes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
perf probe: Detect probe target when m/x options are absent
perf probe: Provide perf interface for uprobes
tracing: Fix kconfig warning due to a typo
tracing: Provide trace events interface for uprobes
tracing: Extract out common code for kprobes/uprobes trace events
tracing: Modify is_delete, is_return from int to bool
uprobes/core: Decrement uprobe count before the pages are unmapped
uprobes/core: Make background page replacement logic account for rss_stat counters
uprobes/core: Optimize probe hits with the help of a counter
uprobes/core: Allocate XOL slots for uprobes use
uprobes/core: Handle breakpoint and singlestep exceptions
uprobes/core: Rename bkpt to swbp
uprobes/core: Make order of function parameters consistent across functions
uprobes/core: Make macro names consistent
uprobes: Update copyright notices
uprobes/core: Move insn to arch specific structure
uprobes/core: Remove uprobe_opcode_sz
uprobes/core: Make instruction tables volatile
uprobes: Move to kernel/events/
uprobes/core: Clean up, refactor and improve the code
...
Pull first series of signal handling cleanups from Al Viro:
"This is just the first part of the queue (about a half of it);
assorted fixes all over the place in signal handling.
This one ends with all sigsuspend() implementations switched to
generic one (->saved_sigmask-based).
With this, a bunch of assorted old buglets are fixed and most of the
missing bits of NOTIFY_RESUME hookup are in place. Two more fixes sit
in arm and um trees respectively, and there's a couple of broken ones
that need obvious fixes - parisc and avr32 check TIF_NOTIFY_RESUME
only on one of two codepaths; fixes for that will happen in the next
series"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (55 commits)
unicore32: if there's no handler we need to restore sigmask, syscall or no syscall
xtensa: add handling of TIF_NOTIFY_RESUME
microblaze: drop 'oldset' argument of do_notify_resume()
microblaze: handle TIF_NOTIFY_RESUME
score: add handling of NOTIFY_RESUME to do_notify_resume()
m68k: add TIF_NOTIFY_RESUME and handle it.
sparc: kill ancient comment in sparc_sigaction()
h8300: missing checks of __get_user()/__put_user() return values
frv: missing checks of __get_user()/__put_user() return values
cris: missing checks of __get_user()/__put_user() return values
powerpc: missing checks of __get_user()/__put_user() return values
sh: missing checks of __get_user()/__put_user() return values
sparc: missing checks of __get_user()/__put_user() return values
avr32: struct old_sigaction is never used
m32r: struct old_sigaction is never used
xtensa: xtensa_sigaction doesn't exist
alpha: tidy signal delivery up
score: don't open-code force_sigsegv()
cris: don't open-code force_sigsegv()
blackfin: don't open-code force_sigsegv()
...
Pull user namespace enhancements from Eric Biederman:
"This is a course correction for the user namespace, so that we can
reach an inexpensive, maintainable, and reasonably complete
implementation.
Highlights:
- Config guards make it impossible to enable the user namespace and
code that has not been converted to be user namespace safe.
- Use of the new kuid_t type ensures the if you somehow get past the
config guards the kernel will encounter type errors if you enable
user namespaces and attempt to compile in code whose permission
checks have not been updated to be user namespace safe.
- All uids from child user namespaces are mapped into the initial
user namespace before they are processed. Removing the need to add
an additional check to see if the user namespace of the compared
uids remains the same.
- With the user namespaces compiled out the performance is as good or
better than it is today.
- For most operations absolutely nothing changes performance or
operationally with the user namespace enabled.
- The worst case performance I could come up with was timing 1
billion cache cold stat operations with the user namespace code
enabled. This went from 156s to 164s on my laptop (or 156ns to
164ns per stat operation).
- (uid_t)-1 and (gid_t)-1 are reserved as an internal error value.
Most uid/gid setting system calls treat these value specially
anyway so attempting to use -1 as a uid would likely cause
entertaining failures in userspace.
- If setuid is called with a uid that can not be mapped setuid fails.
I have looked at sendmail, login, ssh and every other program I
could think of that would call setuid and they all check for and
handle the case where setuid fails.
- If stat or a similar system call is called from a context in which
we can not map a uid we lie and return overflowuid. The LFS
experience suggests not lying and returning an error code might be
better, but the historical precedent with uids is different and I
can not think of anything that would break by lying about a uid we
can't map.
- Capabilities are localized to the current user namespace making it
safe to give the initial user in a user namespace all capabilities.
My git tree covers all of the modifications needed to convert the core
kernel and enough changes to make a system bootable to runlevel 1."
Fix up trivial conflicts due to nearby independent changes in fs/stat.c
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits)
userns: Silence silly gcc warning.
cred: use correct cred accessor with regards to rcu read lock
userns: Convert the move_pages, and migrate_pages permission checks to use uid_eq
userns: Convert cgroup permission checks to use uid_eq
userns: Convert tmpfs to use kuid and kgid where appropriate
userns: Convert sysfs to use kgid/kuid where appropriate
userns: Convert sysctl permission checks to use kuid and kgids.
userns: Convert proc to use kuid/kgid where appropriate
userns: Convert ext4 to user kuid/kgid where appropriate
userns: Convert ext3 to use kuid/kgid where appropriate
userns: Convert ext2 to use kuid/kgid where appropriate.
userns: Convert devpts to use kuid/kgid where appropriate
userns: Convert binary formats to use kuid/kgid where appropriate
userns: Add negative depends on entries to avoid building code that is userns unsafe
userns: signal remove unnecessary map_cred_ns
userns: Teach inode_capable to understand inodes whose uids map to other namespaces.
userns: Fail exec for suid and sgid binaries with ids outside our user namespace.
userns: Convert stat to return values mapped from kuids and kgids
userns: Convert user specfied uids and gids in chown into kuids and kgid
userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs
...
guts of saved_sigmask-based sigsuspend/rt_sigsuspend. Takes
kernel sigset_t *.
Open-coded instances replaced with calling it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
map_cred_ns is a light wrapper around from_kuid with the order of the arguments
reversed. Replace map_cred_ns with from_kuid and remove map_cred_ns.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Update the permission checks to use the new uid_eq and gid_eq helpers
and remove the now unnecessary user_ns equality comparison.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
These function are no longer needed replace them with their more useful equivalents.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
cred.h and a few trivial users of struct cred are changed. The rest of the users
of struct cred are left for other patches as there are too many changes to make
in one go and leave the change reviewable. If the user namespace is disabled and
CONFIG_UIDGID_STRICT_TYPE_CHECKS are disabled the code will contiue to compile
and behave correctly.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This change enables SIGSYS, defines _sigfields._sigsys, and adds
x86 (compat) arch support. _sigsys defines fields which allow
a signal handler to receive the triggering system call number,
the relevant AUDIT_ARCH_* value for that number, and the address
of the callsite.
SIGSYS is added to the SYNCHRONOUS_MASK because it is desirable for it
to have setup_frame() called for it. The goal is to ensure that
ucontext_t reflects the machine state from the time-of-syscall and not
from another signal handler.
The first consumer of SIGSYS would be seccomp filter. In particular,
a filter program could specify a new return value, SECCOMP_RET_TRAP,
which would result in the system call being denied and the calling
thread signaled. This also means that implementing arch-specific
support can be dependent upon HAVE_ARCH_SECCOMP_FILTER.
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Will Drewry <wad@chromium.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Eric Paris <eparis@redhat.com>
v18: - added acked by, rebase
v17: - rebase and reviewed-by addition
v14: - rebase/nochanges
v13: - rebase on to 88ebdda615
v12: - reworded changelog (oleg@redhat.com)
v11: - fix dropped words in the change description
- added fallback copy_siginfo support.
- added __ARCH_SIGSYS define to allow stepped arch support.
v10: - first version based on suggestion
Signed-off-by: James Morris <james.l.morris@oracle.com>
Optimize performance and prepare for the removal of the user_ns reference
from user_struct. Remove the slow long walk through cred->user->user_ns and
instead go straight to cred->user_ns.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system
Pull "Disintegrate and delete asm/system.h" from David Howells:
"Here are a bunch of patches to disintegrate asm/system.h into a set of
separate bits to relieve the problem of circular inclusion
dependencies.
I've built all the working defconfigs from all the arches that I can
and made sure that they don't break.
The reason for these patches is that I recently encountered a circular
dependency problem that came about when I produced some patches to
optimise get_order() by rewriting it to use ilog2().
This uses bitops - and on the SH arch asm/bitops.h drags in
asm-generic/get_order.h by a circuituous route involving asm/system.h.
The main difficulty seems to be asm/system.h. It holds a number of
low level bits with no/few dependencies that are commonly used (eg.
memory barriers) and a number of bits with more dependencies that
aren't used in many places (eg. switch_to()).
These patches break asm/system.h up into the following core pieces:
(1) asm/barrier.h
Move memory barriers here. This already done for MIPS and Alpha.
(2) asm/switch_to.h
Move switch_to() and related stuff here.
(3) asm/exec.h
Move arch_align_stack() here. Other process execution related bits
could perhaps go here from asm/processor.h.
(4) asm/cmpxchg.h
Move xchg() and cmpxchg() here as they're full word atomic ops and
frequently used by atomic_xchg() and atomic_cmpxchg().
(5) asm/bug.h
Move die() and related bits.
(6) asm/auxvec.h
Move AT_VECTOR_SIZE_ARCH here.
Other arch headers are created as needed on a per-arch basis."
Fixed up some conflicts from other header file cleanups and moving code
around that has happened in the meantime, so David's testing is somewhat
weakened by that. We'll find out anything that got broken and fix it..
* tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
Delete all instances of asm/system.h
Remove all #inclusions of asm/system.h
Add #includes needed to permit the removal of asm/system.h
Move all declarations of free_initmem() to linux/mm.h
Disintegrate asm/system.h for OpenRISC
Split arch_align_stack() out from asm-generic/system.h
Split the switch_to() wrapper out of asm-generic/system.h
Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
Create asm-generic/barrier.h
Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
Disintegrate asm/system.h for Xtensa
Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
Disintegrate asm/system.h for Tile
Disintegrate asm/system.h for Sparc
Disintegrate asm/system.h for SH
Disintegrate asm/system.h for Score
Disintegrate asm/system.h for S390
Disintegrate asm/system.h for PowerPC
Disintegrate asm/system.h for PA-RISC
Disintegrate asm/system.h for MN10300
...
Cosmetic, rename the from_ancestor_ns argument in prepare_signal()
paths. After the previous change it doesn't match the reality.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Anton Vorontsov <anton.vorontsov@linaro.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
force_sig_info() and friends have the special semantics for synchronous
signals, this interface should not be used if the target is not current.
And it needs the fixes, in particular the clearing of SIGNAL_UNKILLABLE
is not exactly right.
However there are callers which have to use force_ exactly because it
clears SIGNAL_UNKILLABLE and thus it can kill the CLONE_NEWPID tasks,
although this is almost always is wrong by various reasons.
With this patch SEND_SIG_FORCED ignores SIGNAL_UNKILLABLE, like we do if
the signal comes from the ancestor namespace.
This makes the naming in prepare_signal() paths insane, fixed by the
next cleanup.
Note: this only affects SIGKILL/SIGSTOP, but this is enough for
force_sig() abusers.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Anton Vorontsov <anton.vorontsov@linaro.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
exit_notify() changes ->exit_signal if the parent already did exec.
This doesn't really work, we are not going to send the signal now
if there is another live thread or the exiting task is traced. The
parent can exec before the last dies or the tracer detaches.
Move this check into do_notify_parent() which actually sends the
signal.
The user-visible change is that we do not change ->exit_signal,
and thus the exiting task is still "clone children" for
do_wait()->eligible_child(__WCLONE). Hopefully this is fine, the
current logic is racy anyway.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Uprobes uses exception notifiers to get to know if a thread hit
a breakpoint or a singlestep exception.
When a thread hits a uprobe or is singlestepping post a uprobe
hit, the uprobe exception notifier sets its TIF_UPROBE bit,
which will then be checked on its return to userspace path
(do_notify_resume() ->uprobe_notify_resume()), where the
consumers handlers are run (in task context) based on the
defined filters.
Uprobe hits are thread specific and hence we need to maintain
information about if a task hit a uprobe, what uprobe was hit,
the slot where the original instruction was copied for xol so
that it can be singlestepped with appropriate fixups.
In some cases, special care is needed for instructions that are
executed out of line (xol). These are architecture specific
artefacts, such as handling RIP relative instructions on x86_64.
Since the instruction at which the uprobe was inserted is
executed out of line, architecture specific fixups are added so
that the thread continues normal execution in the presence of a
uprobe.
Postpone the signals until we execute the probed insn.
post_xol() path does a recalc_sigpending() before return to
user-mode, this ensures the signal can't be lost.
Uprobes relies on DIE_DEBUG notification to notify if a
singlestep is complete.
Adds x86 specific uprobe exception notifiers and appropriate
hooks needed to determine a uprobe hit and subsequent post
processing.
Add requisite x86 fixups for xol for uprobes. Specific cases
needing fixups include relative jumps (x86_64), calls, etc.
Where possible, we check and skip singlestepping the
breakpointed instructions. For now we skip single byte as well
as few multibyte nop instructions. However this can be extended
to other instructions too.
Credits to Oleg Nesterov for suggestions/patches related to
signal, breakpoint, singlestep handling code.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com>
Cc: Linux-mm <linux-mm@kvack.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120313180011.29771.89027.sendpatchset@srdronam.in.ibm.com
[ Performed various cleanliness edits ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add trace_signal_generate() into send_sigqueue().
send_sigqueue() is very similar to __send_signal(), just it uses
the preallocated info. It should do the same wrt tracing.
Reported-by: Seiji Aguchi <saguchi@redhat.com>
Reviewed-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
__send_signal()->trace_signal_generate() doesn't report enough info.
The users want to know was the signal actually delivered or not, and
they also need the shared/private info.
The patch moves trace_signal_generate() at the end of __send_signal()
and adds the 2 additional arguments.
This also allows us to kill trace_signal_overflow_fail/lose_info, we
can simply add the appropriate TRACE_SIGNAL_ "result" codes.
Reported-by: Seiji Aguchi <saguchi@redhat.com>
Reviewed-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
ipc/mqueue.c: for __SI_MESQ, convert the uid being sent to recipient's
user namespace. (new, thanks Oleg)
__send_signal: convert current's uid to the recipient's user namespace
for any siginfo which is not SI_FROMKERNEL (patch from Oleg, thanks
again :)
do_notify_parent and do_notify_parent_cldstop: map task's uid to parent's
user namespace
ptrace_signal maps parent's uid into current's user namespace before
including in signal to current. IIUC Oleg has argued that this shouldn't
matter as the debugger will play with it, but it seems like not converting
the value currently being set is misleading.
Changelog:
Sep 20: Inspired by Oleg's suggestion, define map_cred_ns() helper to
simplify callers and help make clear what we are translating
(which uid into which namespace). Passing the target task would
make callers even easier to read, but we pass in user_ns because
current_user_ns() != task_cred_xxx(current, user_ns).
Sep 20: As recommended by Oleg, also put task_pid_vnr() under rcu_read_lock
in ptrace_signal().
Sep 23: In send_signal(), detect when (user) signal is coming from an
ancestor or unrelated user namespace. Pass that on to __send_signal,
which sets si_uid to 0 or overflowuid if needed.
Oct 12: Base on Oleg's fixup_uid() patch. On top of that, handle all
SI_FROMKERNEL cases at callers, because we can't assume sender is
current in those cases.
Nov 10: (mhelsley) rename fixup_uid to more meaningful usern_fixup_signal_uid
Nov 10: (akpm) make the !CONFIG_USER_NS case clearer
Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
From: Serge Hallyn <serge.hallyn@canonical.com>
Subject: __send_signal: pass q->info, not info, to userns_fixup_signal_uid (v2)
Eric Biederman pointed out that passing info is a bug and could lead to a
NULL pointer deref to boot.
A collection of signal, securebits, filecaps, cap_bounds, and a few other
ltp tests passed with this kernel.
Changelog:
Nov 18: previous patch missed a leading '&'
Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
From: Dan Carpenter <dan.carpenter@oracle.com>
Subject: ipc/mqueue: lock() => unlock() typo
There was a double lock typo introduced in b085f4bd6b21 "user namespace:
make signal.c respect user namespaces"
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Abstract the code sequence for adding a signal handler's sa_mask to
current->blocked because the sequence is identical for all architectures.
Furthermore, in the past some architectures actually got this code wrong,
so introduce a wrapper that all architectures can use.
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andreas Schwab