linux-toradex.git/include/linux/signal.h, branch v4.5-rc2

kernel/signal.c: unexport sigsuspend()

2015-11-21T00:17:32+00:00

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: 68f3f16d9ad0f1 ("new helper: sigsuspend()")
Signed-off-by: Richard Weinberger 
Reported-by: Vegard Nossum 
Tested-by: Vegard Nossum 
Acked-by: Oleg Nesterov 
Cc: 	[3.5+]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

signal: use BUILD_BUG() instead of _NSIG_WORDS_is_unsupported_size()

2014-10-14T00:18:20+00:00

Kill _NSIG_WORDS_is_unsupported_size(), use BUILD_BUG() instead.  This
simplifies the code, avoids the nested-externs warnings, and this way we
do not defer the problem to linker.

Also, fix the indentation in _SIG_SET_BINOP() and _SIG_SET_OP().

Note: this patch assumes that the code like "if (0) BUILD_BUG();" is
valid.  If not (say __compiletime_error() is not defined and thus
__compiletime_error_fallback() uses a negative array) we should fix
BUILD_BUG() and/or BUILD_BUG_ON_MSG().  This code should be fine by
definition, this is the documented purpose of BUILD_BUG().

[sfr@canb.auug.org.au: fix powerpc build failures]
Signed-off-by: Oleg Nesterov 
Reported-by: Jeff Kirsher 
Reviewed-by: Josh Triplett 
Signed-off-by: Stephen Rothwell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Rip out get_signal_to_deliver()

2014-08-06T11:03:44+00:00

Now we can turn get_signal() to the main function.

Signed-off-by: Richard Weinberger

Clean up signal_delivered()

2014-08-06T11:03:43+00:00

 - 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

signals: introduce kernel_sigaction()

2014-06-06T23:08:12+00:00

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 
Cc: Peter Zijlstra 
Cc: Al Viro 
Cc: David Woodhouse 
Cc: Frederic Weisbecker 
Cc: Geert Uytterhoeven 
Cc: Ingo Molnar 
Cc: Mathieu Desnoyers 
Cc: Richard Weinberger 
Cc: Steven Rostedt 
Cc: Tejun Heo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

signals: mv {dis,}allow_signal() from sched.h/exit.c to signal.[ch]

2014-06-06T23:08:11+00:00

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 
Cc: Peter Zijlstra 
Cc: Al Viro 
Cc: David Woodhouse 
Cc: Frederic Weisbecker 
Cc: Geert Uytterhoeven 
Cc: Ingo Molnar 
Cc: Mathieu Desnoyers 
Cc: Richard Weinberger 
Cc: Steven Rostedt 
Cc: Tejun Heo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

signals: kill sigfindinword()

2014-06-06T23:08:11+00:00

It has no users and it doesn't look useful.  I do not know why/when it was
introduced, I can't even find any user in the git history.

Signed-off-by: Oleg Nesterov 
Acked-by: Geert Uytterhoeven 
Cc: Peter Zijlstra 
Cc: Al Viro 
Cc: David Woodhouse 
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Mathieu Desnoyers 
Cc: Richard Weinberger 
Cc: Steven Rostedt 
Cc: Tejun Heo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Introduce [compat_]save_altstack_ex() to unbreak x86 SMAP

2013-09-01T21:16:33+00:00

For performance reasons, when SMAP is in use, SMAP is left open for an
entire put_user_try { ... } put_user_catch(); block, however, calling
__put_user() in the middle of that block will close SMAP as the
STAC..CLAC constructs intentionally do not nest.

Furthermore, using __put_user() rather than put_user_ex() here is bad
for performance.

Thus, introduce new [compat_]save_altstack_ex() helpers that replace
__[compat_]save_altstack() for x86, being currently the only
architecture which supports put_user_try { ... } put_user_catch().

Reported-by: H. Peter Anvin 
Signed-off-by: Al Viro 
Signed-off-by: H. Peter Anvin 
Cc:  # v3.8+
Link: http://lkml.kernel.org/n/tip-es5p6y64if71k8p5u08agv9n@git.kernel.org

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2013-05-02T00:51:54+00:00

Pull VFS updates from Al Viro,

Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).

7kloc removed.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
  don't bother with deferred freeing of fdtables
  proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
  proc: Make the PROC_I() and PDE() macros internal to procfs
  proc: Supply a function to remove a proc entry by PDE
  take cgroup_open() and cpuset_open() to fs/proc/base.c
  ppc: Clean up scanlog
  ppc: Clean up rtas_flash driver somewhat
  hostap: proc: Use remove_proc_subtree()
  drm: proc: Use remove_proc_subtree()
  drm: proc: Use minor->index to label things, not PDE->name
  drm: Constify drm_proc_list[]
  zoran: Don't print proc_dir_entry data in debug
  reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
  proc: Supply an accessor for getting the data from a PDE's parent
  airo: Use remove_proc_subtree()
  rtl8192u: Don't need to save device proc dir PDE
  rtl8187se: Use a dir under /proc/net/r8180/
  proc: Add proc_mkdir_data()
  proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
  proc: Move PDE_NET() to fs/proc/proc_net.c
  ...

proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}

2013-05-01T21:29:40+00:00

Move some bits from linux/proc_fs.h to linux/of.h, signal.h and tty.h.

Also move proc_tty_init() and proc_device_tree_init() to fs/proc/internal.h as
they're internal to procfs.

Signed-off-by: David Howells 
Acked-by: Greg Kroah-Hartman 
Acked-by: Grant Likely 
cc: devicetree-discuss@lists.ozlabs.org
cc: linux-arch@vger.kernel.org
cc: Greg Kroah-Hartman 
cc: Jri Slaby 
Signed-off-by: Al Viro