linux.git/fs/proc/array.c, branch v4.14-rc2

fs/proc: Report eip/esp in /prod/PID/stat for coredumping

2017-09-15T21:31:16+00:00

Commit 0a1eb2d474ed ("fs/proc: Stop reporting eip and esp in
/proc/PID/stat") stopped reporting eip/esp because it is
racy and dangerous for executing tasks. The comment adds:

    As far as I know, there are no use programs that make any
    material use of these fields, so just get rid of them.

However, existing userspace core-dump-handler applications (for
example, minicoredumper) are using these fields since they
provide an excellent cross-platform interface to these valuable
pointers. So that commit introduced a user space visible
regression.

Partially revert the change and make the readout possible for
tasks with the proper permissions and only if the target task
has the PF_DUMPCORE flag set.

Fixes: 0a1eb2d474ed ("fs/proc: Stop reporting eip and esp in> /proc/PID/stat")
Reported-by: Marco Felsch 
Signed-off-by: John Ogness 
Reviewed-by: Andy Lutomirski 
Cc: Tycho Andersen 
Cc: Kees Cook 
Cc: Peter Zijlstra 
Cc: Brian Gerst 
Cc: stable@vger.kernel.org
Cc: Tetsuo Handa 
Cc: Borislav Petkov 
Cc: Al Viro 
Cc: Linux API 
Cc: Andrew Morton 
Cc: Linus Torvalds 
Link: http://lkml.kernel.org/r/87poatfwg6.fsf@linutronix.de
Signed-off-by: Thomas Gleixner

sched/headers: Prepare to move cputime functionality from into

2017-03-02T07:42:39+00:00

Introduce a trivial, mostly empty  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 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:35+00:00

We are going to split  out of , which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder  file that just
maps to  to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:30+00:00

We are going to split  out of , which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder  file that just
maps to  to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:28+00:00

We are going to split  out of , which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder  file that just
maps to  to make this patch obviously correct and
bisectable.

The APIs that are going to be moved first are:

   mm_alloc()
   __mmdrop()
   mmdrop()
   mmdrop_async_fn()
   mmdrop_async()
   mmget_not_zero()
   mmput()
   mmput_async()
   get_task_mm()
   mm_access()
   mm_release()

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

sched/cputime: Convert task/group cputime to nsecs

2017-02-01T08:13:49+00:00

Now that most cputime readers use the transition API which return the
task cputime in old style cputime_t, we can safely store the cputime in
nsecs. This will eventually make cputime statistics less opaque and more
granular. Back and forth convertions between cputime_t and nsecs in order
to deal with cputime_t random granularity won't be needed anymore.

Signed-off-by: Frederic Weisbecker 
Cc: Benjamin Herrenschmidt 
Cc: Fenghua Yu 
Cc: Heiko Carstens 
Cc: Linus Torvalds 
Cc: Martin Schwidefsky 
Cc: Michael Ellerman 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Cc: Stanislaw Gruszka 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Wanpeng Li 
Link: http://lkml.kernel.org/r/1485832191-26889-8-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar

sched/cputime: Convert guest time accounting to nsecs (u64)

2017-02-01T08:13:48+00:00

cputime_t is being obsolete and replaced by nsecs units in order to make
internal timestamps less opaque and more granular.

Signed-off-by: Frederic Weisbecker 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Michael Ellerman 
Cc: Heiko Carstens 
Cc: Martin Schwidefsky 
Cc: Tony Luck 
Cc: Fenghua Yu 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Cc: Stanislaw Gruszka 
Cc: Wanpeng Li 
Link: http://lkml.kernel.org/r/1485832191-26889-6-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar

fs/proc/array.c: slightly improve render_sigset_t

2016-12-13T02:55:09+00:00

format_decode and vsnprintf occasionally show up in perf top, so I went
looking for places that might not need the full printf power.  With the
help of kprobes, I gathered some statistics on which format strings we
mostly pass to vsnprintf.  On a trivial desktop workload, I hit "%x" 25%
of the time, so something apparently reads /proc/pid/status (which does
5*16 printf("%x") calls) a lot.

With this patch, reading /proc/pid/status is 30% faster according to
this microbenchmark:

	char buf[4096];
	int i, fd;
	for (i = 0; i < 10000; ++i) {
		fd = open("/proc/self/status", O_RDONLY);
		read(fd, buf, sizeof(buf));
		close(fd);
	}

Link: http://lkml.kernel.org/r/1474410485-1305-1-git-send-email-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes 
Acked-by: Andrei Vagin 
Acked-by: Kees Cook 
Cc: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

proc: report no_new_privs state

2016-12-13T02:55:09+00:00

Similar to being able to examine if a process has been correctly
confined with seccomp, the state of no_new_privs is equally interesting,
so this adds it to /proc/$pid/status.

Link: http://lkml.kernel.org/r/20161103214041.GA58566@beast
Signed-off-by: Kees Cook 
Reviewed-by: Jann Horn 
Cc: Jonathan Corbet 
Cc: Vlastimil Babka 
Cc: Michal Hocko 
Cc: Konstantin Khlebnikov 
Cc: Hugh Dickins 
Cc: Naoya Horiguchi 
Cc: Rodrigo Freire 
Cc: John Stultz 
Cc: Ross Zwisler 
Cc: Robert Ho 
Cc: Jerome Marchand 
Cc: Andy Lutomirski 
Cc: Johannes Weiner 
Cc: Alexey Dobriyan 
Cc: "Richard W.M. Jones" 
Cc: Joe Perches 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs/proc: Stop reporting eip and esp in /proc/PID/stat

2016-10-20T07:21:41+00:00

Reporting these fields on a non-current task is dangerous.  If the
task is in any state other than normal kernel code, they may contain
garbage or even kernel addresses on some architectures.  (x86_64
used to do this.  I bet lots of architectures still do.)  With
CONFIG_THREAD_INFO_IN_TASK=y, it can OOPS, too.

As far as I know, there are no use programs that make any material
use of these fields, so just get rid of them.

Reported-by: Jann Horn 
Signed-off-by: Andy Lutomirski 
Acked-by: Thomas Gleixner 
Cc: Al Viro 
Cc: Andrew Morton 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Kees Cook 
Cc: Linus Torvalds 
Cc: Linux API 
Cc: Peter Zijlstra 
Cc: Tetsuo Handa 
Cc: Tycho Andersen 
Link: http://lkml.kernel.org/r/a5fed4c3f4e33ed25d4bb03567e329bc5a712bcc.1475257877.git.luto@kernel.org
Signed-off-by: Ingo Molnar