Clean asm/system.h from docs as nothing should refer to that header anymore.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus 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: NGideon Israel Dsouza <gidisrael@gmail.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If the renamed symbol is defined lib/iomap.c implements ioport_map and
ioport_unmap and currently (nearly) all platforms define the port
accessor functions outb/inb and friend unconditionally.  So
HAS_IOPORT_MAP is the better name for this.

Consequently NO_IOPORT is renamed to NO_IOPORT_MAP.

The motivation for this change is to reintroduce a symbol HAS_IOPORT
that signals if outb/int et al are available.  I will address that at
least one merge window later though to keep surprises to a minimum and
catch new introductions of (HAS|NO)_IOPORT.

The changes in this commit were done using:

	$ git grep -l -E '(NO|HAS)_IOPORT' | xargs perl -p -i -e 's/\b((?:CONFIG_)?(?:NO|HAS)_IOPORT)\b/$1_MAP/'
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

... since __initcall is now deprecated.
Signed-off-by: NDavidlohr Bueso <davidlohr@hp.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This macro appears to have been introduced back in the 2.5 era for
semtimedop32 backward compatibility on ia32:

  https://lkml.org/lkml/2003/4/28/78

Nowadays, this syscall in compat just defaults back to the code found in
sem.c, so it is no longer used and can thus be removed:

long compat_sys_semtimedop(int semid, struct sembuf __user *tsems,
		unsigned nsops, const struct compat_timespec __user *timeout)
{
	struct timespec __user *ts64;
	if (compat_convert_timespec(&ts64, timeout))
		return -EFAULT;
	return sys_semtimedop(semid, tsems, nsops, ts64);
}

Furthermore, there are no users in compat.c.  After this change, kernel
builds just fine with both CONFIG_SYSVIPC_COMPAT and CONFIG_SYSVIPC.
Signed-off-by: NDavidlohr Bueso <davidlohr@hp.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This can greatly aid in narrowing down the real source of initramfs
problems such as failures related to the compression of the in-kernel
initramfs when an external initramfs is in use as well.  Existing errors
are ambiguous as to which initramfs is a problem and why.

[akpm@linux-foundation.org: use pr_debug()]
Signed-off-by: NDaniel M. Weeks <dan@danweeks.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

/proc/self/make-it-fail is a boolean, but accepts any number, including
negative ones.  Change variable to unsigned, and cap upper bound at 1.

[akpm@linux-foundation.org: don't make make_it_fail unsigned]
Signed-off-by: NDave Jones <davej@fedoraproject.org>
Reviewed-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This ensures that BUG() always has a definition that causes a trap (via
an undefined instruction), and that the compiler still recognizes the
code following BUG() as unreachable, avoiding warnings that would
otherwise appear (such as on non-void functions that don't return a
value after BUG()).

In addition to saving a few bytes over the generic infinite-loop
implementation, this implementation traps rather than looping, which
potentially allows for better error-recovery behavior (such as by
rebooting).
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Reported-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When !CONFIG_BUG and !HAVE_ARCH_BUG, define the generic BUG() as an
infinite loop rather than a no-op.  This avoids undefined behavior if
execution ever actually reaches BUG(), and avoids warnings about code
after BUG() (such as on non-void functions calling BUG() and then not
returning).

bloat-o-meter results:

  add/remove: 0/0 grow/shrink: 43/10 up/down: 235/-98 (137)
  function                             old     new   delta
  umount_collect                       119     138     +19
  notify_change                        306     324     +18
  xstate_enable_boot_cpu               252     269     +17
  kunmap                                54      70     +16
  balloon_page_dequeue                 112     126     +14
  mm_take_all_locks                    223     233     +10
  list_lru_walk_node                   143     152      +9
  vma_adjust                          1059    1067      +8
  pcpu_setup_first_chunk              1130    1138      +8
  mm_drop_all_locks                    143     151      +8
  ns_capable                            55      62      +7
  anon_transport_class_unregister        8      15      +7
  srcu_init_notifier_head               35      41      +6
  shrink_dcache_for_umount             174     180      +6
  kunmap_high                           99     105      +6
  end_page_writeback                    43      49      +6
  do_exit                             1339    1345      +6
  __kfifo_dma_out_prepare_r             86      92      +6
  __kfifo_dma_in_prepare_r              90      96      +6
  fixup_user_fault                     120     125      +5
  repair_env_string                     73      77      +4
  read_cache_pages_invalidate_page      56      60      +4
  isolate_lru_pages.isra               142     146      +4
  do_notify_parent_cldstop             255     259      +4
  cpu_init                             370     374      +4
  utimes_common                        270     272      +2
  tasklet_hi_action                     91      93      +2
  tasklet_action                        91      93      +2
  set_pte_vaddr                         46      48      +2
  find_get_pages_tag                   202     204      +2
  early_iounmap                        185     187      +2
  __native_set_fixmap                   36      38      +2
  __get_user_pages                     822     824      +2
  __early_ioremap                      299     301      +2
  yield_task_stop                        1       2      +1
  tick_resume                           37      38      +1
  switched_to_stop                       1       2      +1
  switched_to_idle                       1       2      +1
  prio_changed_stop                      1       2      +1
  prio_changed_idle                      1       2      +1
  pm_qos_power_read                    111     112      +1
  arch_cpu_idle_dead                     1       2      +1
  __insert_vmap_area                   140     141      +1
  sys_renameat                         614     612      -2
  mm_fault_error                       297     295      -2
  SyS_renameat                         614     612      -2
  sys_linkat                           416     413      -3
  SyS_linkat                           416     413      -3
  chmod_common                         129     122      -7
  proc_cap_handler                     240     225     -15
  __schedule                           849     831     -18
  sys_madvise                         1077    1054     -23
  SyS_madvise                         1077    1054     -23
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Reported-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The stub version of WARN for !CONFIG_BUG completely ignored its format
string and subsequent arguments; make it check them instead, using
no_printk.
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Reported-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Reported-by: NRandy Dunlap <rdunlap@infradead.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When !CONFIG_BUG, WARN_ON and family become simple passthroughs of their
condition argument; however, WARN_ON_ONCE and family still have conditions
and a boolean to detect one-time invocation, even though the warning
they'd emit doesn't exist.  Make the existing definitions conditional on
CONFIG_BUG, and add definitions for !CONFIG_BUG that map to the
passthrough versions of WARN and WARN_ON.

This saves 4.4k on a minimized configuration (smaller than allnoconfig),
and 20.6k with defconfig plus CONFIG_BUG=n.
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

"make allnoconfig" exists to ease testing of minimal configurations.
Documentation/SubmitChecklist includes a note to test with allnoconfig.
This helps catch missing dependencies on common-but-not-required
functionality, which might otherwise go unnoticed.

However, allnoconfig still leaves many symbols enabled, because they're
hidden behind CONFIG_EMBEDDED or CONFIG_EXPERT.  For instance, allnoconfig
still has CONFIG_PRINTK and CONFIG_BLOCK enabled, so drivers don't
typically get build-tested with those disabled.

To address this, introduce a new Kconfig option "allnoconfig_y", used on
symbols which only exist to hide other symbols.  Set it on CONFIG_EMBEDDED
(which then selects CONFIG_EXPERT).  allnoconfig will then disable all the
symbols hidden behind those.
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Tested-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix breakage which will be exposed by the patch "kconfig: make allnoconfig
disable options behind EMBEDDED and EXPERT".

arch/powerpc/kernel/mce.c, compiled in for PPC_BOOK3S_64, calls
functions only built when IRQ_WORK, so select it.  Fixes the following
build error:

  arch/powerpc/kernel/built-in.o: In function `.machine_check_queue_event':
  (.text+0x11260): undefined reference to `.irq_work_queue'
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix breakage which will be exposed by the patch "kconfig: make allnoconfig
disable options behind EMBEDDED and EXPERT".

arch/ia64/kernel/unaligned.c uses tty_write_message to print an
unaligned access exception to the TTY of the current user process.
Enable TTY to prevent a build error.

Minimal fix, on the basis that few people on ia64 will care deeply about
kernel size enough to turn off TTY.  Ideally, I'd instead suggest
dropping the tty_write_message entirely, and just leaving the printk.
Bonus: no need to sprintf first.
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix breakage which will be exposed by the patch "kconfig: make allnoconfig
disable options behind EMBEDDED and EXPERT".

Now allnoconfig started disabling CONFIG_PROC_FS:

    arch/cris/kernel/built-in.o:(.rodata+0xc): undefined reference to `show_cpuinfo'
    make: *** [vmlinux] Error 1
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix breakage which will be exposed by the patch "kconfig: make allnoconfig
disable options behind EMBEDDED and EXPERT".

arch/cris/arch-v10/kernel/debugport.c, compiled in unconditionally with
ETRAX_ARCH_V10, requires TTY, so select TTY to avoid a build failure.
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

"ret" is zero here so we can remove the "!ret" part of the condition.
"uhdr" is alread a __user pointer so we can remove the cast.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NDimitri Sivanich <sivanich@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently, booting without initrd specified on 80x25 screen gives a call
trace followed by atkbd : Spurious ACK.  Original message ("VFS: Unable
to mount root fs") is not available.  Of course this could happen in
other situations...

This patch displays panic reason after call trace which could help lot
of people even if it's not the very last line on screen.

Also, convert all panic.c printk(KERN_EMERG to pr_emerg(

[akpm@linux-foundation.org: missed a couple of pr_ conversions]
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

init_inodecache is only called by __init init_bfs_fs
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Normal behavior for filenames exceeding specific filesystem limits is to
refuse operation.

AFFS standard name length being only 30 characters against 255 for usual
Linux filesystems, original implementation does filename truncate by
default with a define value AFFS_NO_TRUNCATE which can be enabled but
needs module compilation.

This patch adds 'nofilenametruncate' mount option so that user can
easily activate that feature and avoid a lot of problems (eg overwrite
files ...)
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 0edf977d ("[readdir] convert affs") returns directly -EIO
without unlocking dir inode and releasing dir bh when second affs_bread
sequence fails.  This patch restores initial behaviour.  It also fixes
pr_debug and affs_error to fit in 80 columns + removes reference to
filldir (replaced by dir_emit in the commit above).
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

init_inodecache is only called by __init init_affs_fs
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

init_inodecache is only called by __init init_adfs_fs.
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As sysctl_hung_task_timeout_sec is unsigned long, when this value is
larger then LONG_MAX/HZ, the function schedule_timeout_interruptible in
watchdog will return immediately without sleep and with print :

  schedule_timeout: wrong timeout value ffffffffffffff83

and then the funtion watchdog will call schedule_timeout_interruptible
again and again.  The screen will be filled with

	"schedule_timeout: wrong timeout value ffffffffffffff83"

This patch does some check and correction in sysctl, to let the function
schedule_timeout_interruptible allways get the valid parameter.
Signed-off-by: NLiu Hua <sdu.liu@huawei.com>
Tested-by: NSatoru Takeuchi <satoru.takeuchi@gmail.com>
Cc: <stable@vger.kernel.org>	[3.4+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch removes an artificial RapidIO bus root device and establishes
actual device hierarchy by providing reference to real parent devices.
It also introduces device class for RapidIO controller devices (on-chip
or an eternal bridge, known as "mport").

Existing implementation was sufficient for SoC-based platforms that have
a single RapidIO controller.  With introduction of devices using
multiple RapidIO controllers and PCIe-to-RapidIO bridges the old scheme
is very limiting or does not work at all.  The implemented changes allow
to properly reference platform's local RapidIO mport devices and provide
device details needed for upper layers.

This change to RapidIO device hierarchy does not break any known
existing kernel or user space interfaces.
Signed-off-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com>
Cc: Stef van Os <stef.van.os@prodrive-technologies.com>
Cc: Jerry Jacobs <jerry.jacobs@prodrive-technologies.com>
Cc: Arno Tiemersma <arno.tiemersma@prodrive-technologies.com>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Combine SG entries describing single contiguous memory block into one
Tsi721 BDMA descriptor.  This reduces number of hardware descriptors
required for large data transfers and improves performance on the PCIe
side by reducing number of descriptor fetch requests.
Signed-off-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, NULL)

The rcu_assign_pointer() ensures that the initialization of a structure
is carried out before storing a pointer to that structure.  And in the
case of the NULL pointer, there is no structure to initialize.

So, rcu_assign_pointer(p, NULL) can be safely converted to
RCU_INIT_POINTER(p, NULL)
Signed-off-by: NMonam Agarwal <monamagarwal123@gmail.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove no longer used deprecated code, and make local functions
static.
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Acked-by: NJean Delvare <jdelvare@suse.de>
Acked-by: NTejun Heo <tj@kernel.org>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: George Spelvin <linux@horizon.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently when an empty PT_NOTE is detected, vmcore initialization
fails.  It sounds too harsh.  Because PT_NOTE could be empty, for
example, one offlined a cpu but never restarted kdump service, and after
crash, PT_NOTE program header is there but no data contains.  It's
better to warn about the empty PT_NOTE and continue to initialise
vmcore.

And ultimately the multiple PT_NOTE are merged into a single one, all
empty PT_NOTE are discarded naturally during the merge.  So empty
PT_NOTE is not visible to user space and vmcore is as good as expected.
Signed-off-by: NWANG Chao <chaowang@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Greg Pearson <greg.pearson@hp.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Eliminate the following warning in proc/vmcore.c:

  fs/proc/vmcore.c:1088:6: warning: no previous prototype for `vmcore_cleanup' [-Wmissing-prototypes]

[akpm@linux-foundation.org: clean up powerpc, remove unneeded EXPORT_SYMBOL]
Signed-off-by: NRashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Even if the main thread is dead the process still can stop/continue.
However, if the leader is ptraced wait_consider_task(ptrace => false)
always skips wait_task_stopped/wait_task_continued, so WSTOPPED or
WCONTINUED can never work for the natural parent in this case.

Move the "A zombie ptracee is only visible to its ptracer" check into the
"if (!delay_group_leader(p))" block.  ->notask_error is cleared by the
"fall through" code below.

This depends on the previous change, wait_task_stopped/continued must be
avoided if !delay_group_leader() and the tracer is ->real_parent.
Otherwise WSTOPPED|WEXITED could wrongly report "stopped" when the child
is already dead (single-threaded or not).  If it is traced by another task
then the "stopped" state is fine until the debugger detaches and reveals a
zombie state.

Stupid test-case:

	void *tfunc(void *arg)
	{
		sleep(1);	// wait for zombie leader
		raise(SIGSTOP);
		exit(0x13);
		return NULL;
	}

	int run_child(void)
	{
		pthread_t thread;

		if (!fork()) {
			int tracee = getppid();

			assert(ptrace(PTRACE_ATTACH, tracee, 0,0) == 0);
			do
				ptrace(PTRACE_CONT, tracee, 0,0);
			while (wait(NULL) > 0);

			return 0;
		}

		sleep(1);	// wait for PTRACE_ATTACH
		assert(pthread_create(&thread, NULL, tfunc, NULL) == 0);
		pthread_exit(NULL);
	}

	int main(void)
	{
		int child, stat;

		child = fork();
		if (!child)
			return run_child();

		assert(child == waitpid(-1, &stat, WSTOPPED));
		assert(stat == 0x137f);

		kill(child, SIGCONT);

		assert(child == waitpid(-1, &stat, WCONTINUED));
		assert(stat == 0xffff);

		assert(child == waitpid(-1, &stat, 0));
		assert(stat == 0x1300);

		return 0;
	}

Without this patch it hangs in waitpid(WSTOPPED), wait_task_stopped() is
never called.

Note: this doesn't fix all problems with a zombie delay_group_leader(),
WCONTINUED | WEXITED check is not exactly right.  debugger can't assume it
will be notified if another thread reaps the whole thread group.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Michal Schmidt <mschmidt@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

"A zombie is only visible to its ptracer" logic in wait_consider_task()
is very wrong. Trivial test-case:

	#include <unistd.h>
	#include <sys/ptrace.h>
	#include <sys/wait.h>
	#include <assert.h>

	int main(void)
	{
		int child = fork();

		if (!child) {
			assert(ptrace(PTRACE_TRACEME, 0,0,0) == 0);
			return 0x23;
		}

		assert(waitid(P_ALL, child, NULL, WEXITED | WNOWAIT) == 0);
		assert(waitid(P_ALL, 0, NULL, WSTOPPED) == -1);
		return 0;
	}

it hangs in waitpid(WSTOPPED) despite the fact it has a single zombie
child.  This is because wait_consider_task(ptrace => 0) sees p->ptrace and
cleares ->notask_error assuming that the debugger should detach and notify
us.

Change wait_consider_task(ptrace => 0) to pretend that ptrace == T if the
child is traced by us.  This really simplifies the logic and allows us to
do more fixes, see the next changes.  This also hides the unwanted group
stop state automatically, we can remove another ptrace_reparented() check.

Unfortunately, this adds the following behavioural changes:

	1. Before this patch wait(WEXITED | __WNOTHREAD) does not reap
	   a natural child if it is traced by the caller's sub-thread.

	   Hopefully nobody will ever notice this change, and I think
	   that nobody should rely on this behaviour anyway.

	2. SIGNAL_STOP_CONTINUED is no longer hidden from debugger if
	   it is real parent.

	   While this change comes as a side effect, I think it is good
	   by itself. The group continued state can not be consumed by
	   another process in this case, it doesn't depend on ptrace,
	   it doesn't make sense to hide it from real parent.

	   Perhaps we should add the thread_group_leader() check before
	   wait_task_continued()? May be, but this shouldn't depend on
	   ptrace_reparented().
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Michal Schmidt <mschmidt@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

get_task_state() uses the most significant bit to report the state to
user-space, this means that EXIT_ZOMBIE->EXIT_TRACE->EXIT_DEAD transition
can be noticed via /proc as Z -> X -> Z change.  Note that this was
possible even before EXIT_TRACE was introduced.

This is not really bad but imho it make sense to hide EXIT_TRACE from
user-space completely.  So the patch simply swaps EXIT_ZOMBIE and
EXIT_DEAD, this way EXIT_TRACE will be seen as EXIT_ZOMBIE by user-space.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Michal Schmidt <mschmidt@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that EXIT_DEAD is the terminal state it doesn't make sense to call
eligible_child() or security_task_wait() if the task is really dead.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Tested-by: NMichal Schmidt <mschmidt@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

wait_task_zombie() always uses EXIT_TRACE/ptrace_unlink() if
ptrace_reparented().  This is suboptimal and a bit confusing: we do not
need do_notify_parent(p) if !thread_group_leader(p) and in this case we
also do not need ptrace_unlink(), we can rely on ptrace_release_task().

Change wait_task_zombie() to check thread_group_leader() along with
ptrace_reparented() and simplify the final p->exit_state transition.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Tested-by: NMichal Schmidt <mschmidt@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

wait_task_zombie() first does EXIT_ZOMBIE->EXIT_DEAD transition and
drops tasklist_lock.  If this task is not the natural child and it is
traced, we change its state back to EXIT_ZOMBIE for ->real_parent.

The last transition is racy, this is even documented in 50b8d257
"ptrace: partially fix the do_wait(WEXITED) vs EXIT_DEAD->EXIT_ZOMBIE
race".  wait_consider_task() tries to detect this transition and clear
->notask_error but we can't rely on ptrace_reparented(), debugger can
exit and do ptrace_unlink() before its sub-thread sets EXIT_ZOMBIE.

And there is another problem which were missed before: this transition
can also race with reparent_leader() which doesn't reset >exit_signal if
EXIT_DEAD, assuming that this task must be reaped by someone else.  So
the tracee can be re-parented with ->exit_signal != SIGCHLD, and if
/sbin/init doesn't use __WALL it becomes unreapable.  This was fixed by
the previous commit, but it was the temporary hack.

1. Add the new exit_state, EXIT_TRACE. It means that the task is the
   traced zombie, debugger is going to detach and notify its natural
   parent.

   This new state is actually EXIT_ZOMBIE | EXIT_DEAD. This way we
   can avoid the changes in proc/kgdb code, get_task_state() still
   reports "X (dead)" in this case.

   Note: with or without this change userspace can see Z -> X -> Z
   transition. Not really bad, but probably makes sense to fix.

2. Change wait_task_zombie() to use EXIT_TRACE instead of EXIT_DEAD
   if we need to notify the ->real_parent.

3. Revert the previous hack in reparent_leader(), now that EXIT_DEAD
   is always the final state we can safely ignore such a task.

4. Change wait_consider_task() to check EXIT_TRACE separately and kill
   the racy and no longer needed ptrace_reparented() case.

   If ptrace == T an EXIT_TRACE thread should be simply ignored, the
   owner of this state is going to ptrace_unlink() this task. We can
   pretend that it was already removed from ->ptraced list.

   Otherwise we should skip this thread too but clear ->notask_error,
   we must be the natural parent and debugger is going to untrace and
   notify us. IOW, this doesn't differ from "EXIT_ZOMBIE && p->ptrace"
   even if the task was already untraced.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Reported-by: NJan Kratochvil <jan.kratochvil@redhat.com>
Reported-by: NMichal Schmidt <mschmidt@redhat.com>
Tested-by: NMichal Schmidt <mschmidt@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

wait_task_zombie() first does EXIT_ZOMBIE->EXIT_DEAD transition and
drops tasklist_lock.  If this task is not the natural child and it is
traced, we change its state back to EXIT_ZOMBIE for ->real_parent.

The last transition is racy, this is even documented in 50b8d257
"ptrace: partially fix the do_wait(WEXITED) vs EXIT_DEAD->EXIT_ZOMBIE
race".  wait_consider_task() tries to detect this transition and clear
->notask_error but we can't rely on ptrace_reparented(), debugger can
exit and do ptrace_unlink() before its sub-thread sets EXIT_ZOMBIE.

And there is another problem which were missed before: this transition
can also race with reparent_leader() which doesn't reset >exit_signal if
EXIT_DEAD, assuming that this task must be reaped by someone else.  So
the tracee can be re-parented with ->exit_signal != SIGCHLD, and if
/sbin/init doesn't use __WALL it becomes unreapable.

Change reparent_leader() to update ->exit_signal even if EXIT_DEAD.
Note: this is the simple temporary hack for -stable, it doesn't try to
solve all problems, it will be reverted by the next changes.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Reported-by: NJan Kratochvil <jan.kratochvil@redhat.com>
Reported-by: NMichal Schmidt <mschmidt@redhat.com>
Tested-by: NMichal Schmidt <mschmidt@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Starting from commit c4ad8f98 ("execve: use 'struct filename *' for
executable name passing") bprm->filename can not go away after
flush_old_exec(), so we do not need to save the binary name in
bprm->tcomm[] added by 96e02d15 ("exec: fix use-after-free bug in
setup_new_exec()").

And there was never need for filename_to_taskname-like code, we can
simply do set_task_comm(kbasename(filename).

This patch has to change set_task_comm() and trace_task_rename() to
accept "const char *", but I think this change is also good.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The /proc/*/pagemap contain sensitive information and currently its mode
is 0444.  Change this to 0400, so the VFS will prevent unprivileged
processes from getting file descriptors on arbitrary privileged
/proc/*/pagemap files.

This reduces the scope of address space leaking and bypasses by protecting
already running processes.
Signed-off-by: NDjalal Harouni <tixxdz@opendz.org>
Acked-by: NKees Cook <keescook@chromium.org>
Acked-by: NAndy Lutomirski <luto@amacapital.net>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>