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>
We have nice method simple_strtoul() to convert string to numbers which
could be used here.
Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch prevents the code from calling parport_release and
parport_unregister_device twice with the same arguments - and thus fixes an oops.
Rationale:
After the first call the parport is already released and the
handle isn't valid anymore and calling parport_release and
parport_unregister_device twice isn't a good idea.
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Cc: stable <stable@kernel.org>
Acked-by: Willy Tarreau <w@1wt.eu>
Fixed coding convention issues as reported by checkpatch.pl tool
on the file `panel.c'. Moved LCD special code handling from the
function `lcd_write' into function `handle_lcd_special_code'. Also
moved the handling of INPUT_ST_HIGH and INPUT_ST_FALLING states from
the function `panel_process_input' into functions `input_state_high'
and `input_state_falling'.
Signed-off-by: Henri Häkkinen <henuxd@gmail.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use kcalloc or kzalloc rather than the combination of kmalloc and memset.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression x,y,flags;
statement S;
type T;
@@
x =
- kmalloc
+ kcalloc
(
- y * sizeof(T),
+ y, sizeof(T),
flags);
if (x == NULL) S
-memset(x, 0, y * sizeof(T));
@@
expression x,size,flags;
statement S;
@@
-x = kmalloc(size,flags);
+x = kzalloc(size,flags);
if (x == NULL) S
-memset(x, 0, size);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
This patch replaces <asm/uaccess.h> with <linux/uaccess.h> to comply with
the checkpatch.pl hint.
Signed-off-by: Takanori Suzuki <mail.tks@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
BKL isn't anymore present into these files thus it is no necessary still include smp_lock.h.
Signed-off-by: Alessio Igor Bogani <abogani@texware.it>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In panel.c there are only the values 0-3 defined. So 4 is invalid:
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When compiling panel.c with a DEFAULT_LCD_CHARSET it fails to compile
with the following error message:
drivers/staging/panel/panel.c: In function >>lcd_init<<:
drivers/staging/panel/panel.c:1396: error: expected expression before
>>;<< token
drivers/staging/panel/panel.c:1475: error: expected expression before
>>;<< token
make[3]: *** [drivers/staging/panel/panel.o] error 1
make[2]: *** [drivers/staging/panel] error 2
make[1]: *** [drivers/staging] error 2
The config used was:
CONFIG_PANEL=m
CONFIG_PANEL_PARPORT=0
CONFIG_PANEL_PROFILE=0
CONFIG_PANEL_KEYPAD=0
CONFIG_PANEL_LCD=1
CONFIG_PANEL_LCD_HEIGHT=2
CONFIG_PANEL_LCD_WIDTH=20
CONFIG_PANEL_LCD_BWIDTH=40
CONFIG_PANEL_LCD_HWIDTH=64
CONFIG_PANEL_LCD_CHARSET=0
CONFIG_PANEL_LCD_PROTO=0
CONFIG_PANEL_LCD_PIN_E=14
CONFIG_PANEL_LCD_PIN_RS=17
CONFIG_PANEL_LCD_PIN_RW=16
CONFIG_PANEL_LCD_PIN_BL=0
This patch fixes both errors, as it fixes the define
Patch against current linux-next tree at Tue Dec 15 06:07:01 2009 +0100
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch prevents the driver from calling misc_deregister twice on the same
ressouce when unloading the driver.
Unloading the driver without this patch results in a Kernel BUG like this:
Panel driver version 0.9.5 registered on parport0 (io=0x378).
BUG: unable to handle kernel paging request at 0000000000100108
IP: [<ffffffff803c02ee>] misc_deregister+0x2d/0x90
PGD 6caff067 PUD 762b7067 PMD 0
Oops: 0002 [#1] PREEMPT SMP
last sysfs file: /sys/devices/platform/w83627hf.656/in8_input
...
This patch fixes this issue, although maybe not in the best way possible :)
linux version v2.6.32-rc1 - linus git tree, Di 29. Sep 01:10:18 CEST 2009
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On TI DA850/OMAP-L138 EVM, HD44780 (24x2) LCD panel is being
used[1], but it is interfaced through the SoC specific LCD
interface and not through parallel port. A parallel port
driver has been developed which interfaces to the panel driver
through the SoC specific LCD interface.
Basically, both the serial and parallel interfaces supported
by the panel driver do not suit the specific interface SoC is
supporting so, a new interface type has been introduced.
Ideally the panel driver should be de-coupled from parallel
and serial port related items but this patch is something
that can be merged in the meantime.
[1]Specification of the character LCD interface on TI DA850/OMAP-L138:
http://www.ti.com/litv/pdf/sprufm0a.
Signed-off-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Smartcard support was more like a proof-of-concept than a completed
work. It was only able to read serial numbers from a few smartcards,
and the goal was to be able to secure keypad access with a smartcard.
Given how the concept was limited, this was never used beyond demos,
and it's better to remove this code so that nobody tries to use it
for security purposes.
The function panel_bind_callback() was ifdef'ed out, as its only user
was smartcard. However, it would be a waste to remove it because many
variations made on this driver will need it.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Cc: Frank Menne <frank.menne@hsm.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The code began 8 years ago with kernel 2.0 or 2.1, and kernels 2.2 and
2.4 were still supported. These old version need no longer be supported
if the code gets merged in mainline.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Cc: Frank Menne <frank.menne@hsm.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
All of the 401 errors, and 108 of the 235 warnings reported by checkpatch
were cleared. The only remanining warnings left concern lines larger than
80 characters. This cleanup will be performed last.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Cc: Frank Menne <frank.menne@hsm.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This adds the lcd-panel parallel port driver to the staging tree.
See the file, drivers/staging/panel/TODO for what needs to be fixed up
in order for this to be properly merged into the rest of the kernel
tree.
Cc: Willy Tarreau <w@1wt.eu>
Cc: Frank Menne <frank.menne@hsm.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
