llseek: automatically add .llseek fop

All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three

llseek: automatically add .llseek fop

All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time. Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
// but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
.llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
.read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
.write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
.open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
... .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
... .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
... .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+ .llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
.write = write_f,
.read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>

show more ...

Input: uinput - setup MT usage during device creation

The input devices created by uinput do not currently handle multitouch
properly. All events will appear as if they came from slot zero, and
the

Input: uinput - setup MT usage during device creation

The input devices created by uinput do not currently handle multitouch
properly. All events will appear as if they came from slot zero, and
the input event buffers are not adjusted. This patch creates the MT
slots during setup, and sets the number of events per packet based
on the MT usage.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

show more ...

Input: uinput - add devname alias to allow module on-demand load

Recent modprobe and udev versions allow to create device nodes
for modules which are not loaded. Only the first access will cause
the

Input: uinput - add devname alias to allow module on-demand load

Recent modprobe and udev versions allow to create device nodes
for modules which are not loaded. Only the first access will cause
the in-kernel module loader to pull-in the module. Systems which
never access the device node will not needlessly load the module,
and no longer need init scripts or other facilities to unconditionally
load it.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

show more ...

Input: switch to input_abs_*() access functions

Change all call sites in drivers/input to not access the ABS axis
information directly anymore. Make them use the access helpers instead.

Also use in

Input: switch to input_abs_*() access functions

Change all call sites in drivers/input to not access the ABS axis
information directly anymore. Make them use the access helpers instead.

Also use input_set_abs_params() when possible.
Did some code refactoring as I was on it.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

show more ...

Input: use ABS_CNT rather than (ABS_MAX + 1)

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: uinput - mark as non-seekable

Seeking does not make sense for uinput so let's use nonseekable_open
to mark the device non-seekable.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: uinput - remove BKL from uinput_open function

Commit 8702965848ed4bee27486a3e3d2ae34ebba6dd83 pushed down the BKL
into uinput open function. However, there's nothing that needs locking
in the

Input: uinput - remove BKL from uinput_open function

Commit 8702965848ed4bee27486a3e3d2ae34ebba6dd83 pushed down the BKL
into uinput open function. However, there's nothing that needs locking
in there.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

show more ...

headers: remove sched.h from poll.h

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Input: uinput - flush all pending ff effects before destroying device

The destruction of a input device in uinput is triggered by an ioctl().
If a process tries to destroy an input device while othe

Input: uinput - flush all pending ff effects before destroying device

The destruction of a input device in uinput is triggered by an ioctl().
If a process tries to destroy an input device while other is uploading a
force feedback effect by evdev to the same device, they'll deadlock.
This patch fixes the problem by flushing all pending FF uploads before
destroying the device and preventing new uploads during this operation.

[dtor@mail.ru: fix logic that ensures we don't submit new requests
to the device that is being destroyed.]
Signed-off-by: Aristeu Rozanski <aris@redhat.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

show more ...

Input: refactor evdev 32bit compat to be shareable with uinput

Currently, evdev has working 32bit compatibility and uinput does not. uinput
needs the input_event code that evdev uses, so let's refac

Input: refactor evdev 32bit compat to be shareable with uinput

Currently, evdev has working 32bit compatibility and uinput does not. uinput
needs the input_event code that evdev uses, so let's refactor it so it can
be shared.

[dtor@mail.ru: add fix for force feedback compat issues]
Signed-off-by: Philip Langdale <philipl@overt.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

show more ...

Input: uinput - remove duplicate include

Remove duplicate include file <linux/smp_lock.h> in
drivers/input/misc/uinput.c.

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Dmitry To

Input: uinput - remove duplicate include

Remove duplicate include file <linux/smp_lock.h> in
drivers/input/misc/uinput.c.

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

show more ...

uinput: BKL pushdown

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Input: pull input.h into uinpit.h

uinput.h relies on structures found in input.h, so pull in the header

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.r

Input: pull input.h into uinpit.h

uinput.h relies on structures found in input.h, so pull in the header

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

show more ...

Input: drivers/input/misc - don't access dev->private directly

Use input_get_drvdata() and input_set_drvdata() instead.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

[PATCH] mark struct file_operations const 3

Many struct file_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potentia

[PATCH] mark struct file_operations const 3

Many struct file_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data. In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

Input: uinput - switch to the new FF interface

The userspace interface of the force feedback part is changed and
documentation in uinput.h is updated accordingly. MODULE_VERSION
is also incremented

Input: uinput - switch to the new FF interface

The userspace interface of the force feedback part is changed and
documentation in uinput.h is updated accordingly. MODULE_VERSION
is also incremented to reflect the revision.

Signed-off-by: Anssi Hannula <anssi.hannula@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

show more ...

Input: uinput - semaphore to mutex conversion

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: uinput - don't use "interruptible" in FF code

If thread that submitted FF request gets interrupted somehow it
will release request structure and ioctl handler will work with
freed memory. TO

Input: uinput - don't use "interruptible" in FF code

If thread that submitted FF request gets interrupted somehow it
will release request structure and ioctl handler will work with
freed memory. TO prevent that from happening switch to using
wait_for_completion instead of wait_for_completion_interruptible.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

show more ...

Input: uinput - add UI_SET_SWBIT ioctl

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: uinput - convert to dynalloc allocation

Also introduce proper locking when creating/deleting device.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

[PATCH] kfree cleanup: misc remaining drivers

This is the remaining misc drivers/ part of the big kfree cleanup patch.

Remove pointless checks for NULL prior to calling kfree() in misc files in
dri

[PATCH] kfree cleanup: misc remaining drivers

This is the remaining misc drivers/ part of the big kfree cleanup patch.

Remove pointless checks for NULL prior to calling kfree() in misc files in
drivers/.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
Acked-by: Roland Dreier <rolandd@cisco.com>
Acked-by: Pierre Ossman <drzeus@drzeus.cx>
Acked-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Len Brown <len.brown@intel.com>
Acked-by: "Antonino A. Daplas" <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

show more ...

[PATCH] uniput - fix crash on SMP

Only signal completion after marking request slot as free, otherwise other
processor can free request structure before we finish using it.

Signed-off-by: Dmitry To

[PATCH] uniput - fix crash on SMP

Only signal completion after marking request slot as free, otherwise other
processor can free request structure before we finish using it.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

show more ...

Input: make name, phys and uniq be 'const char *' because once
set noone should attempt to change them.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: uinput - use completions instead of events and manual
wakeups in force feedback code.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: clean up uinput driver (formatting, extra braces)

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>