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>
Some devices poke the hid core in a way that causes hid_debug_event to
be called, while never calling hid_dump_input. Without this wakeup
addition, tasks reading for hid events through debugfs may never see any
events. It may be that a well written driver doesn't cause this, but
then what's the point of debugfs?
Signed-off-by: Chase Douglas <chase.douglas@canonical.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The path around the loop ends with the lock held, so the call to mutex_lock
is moved before the beginning of the loop.
A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@locked@
expression E1;
position p;
@@
read_lock(E1@p,...);
@r exists@
expression x <= locked.E1;
expression locked.E1;
expression E2;
identifier lock;
position locked.p,p1,p2;
@@
*lock@p1 (E1@p,...);
... when != E1
when != \(x = E2\|&x\)
*lock@p2 (E1,...);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
When dumping /sys/kernel/debug/hid/$device/events '\0' characters show up
(invisible if cat to console but shown by less or while looking at a dump
file). These are due to hid_debug_event() adding strlen()+1 bytes to the ring
buffer (e.g. including the trailing '\0'). Any roll-over causes a '\0' as well
as hid_debug_event() handles the ring buffers with HID_DEBUG_BUFSIZE-1 size
while hid_debug_events_read() handles it with full HID_DEBUG_BUFSIZE size.
Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
hid-debug.c: make local symbols static
The symbols hid_resolv_event and hid_dump_input_mapping
are only used locally in this file. Make them static to prevent
the following sparse warnings:
warning: symbol 'hid_resolv_event' was not declared. Should it be static?
warning: symbol 'hid_dump_input_mapping' was not declared. Should it be static?
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This is a followup patch to the one implemeting rdesc representation in debugfs
rather than being dependent on compile-time CONFIG_HID_DEBUG setting.
The API of the appropriate formatting functions is slightly modified -- if
they are passed seq_file pointer, the one-shot output for 'rdesc' file mode
is used, and therefore the message is formatted into the corresponding seq_file
immediately.
Otherwise the called function allocated a new buffer, formats the text into the
buffer and returns the pointer to it, so that it can be queued into the ring-buffer
of the processess blocked waiting on input on 'events' file in debugfs.
'debug' parameter to the 'hid' module is now used solely for the prupose of inetrnal
driver state debugging (parser, transport, etc).
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
It is a little bit inconvenient for people who have some non-standard
HID hardware (usually violating the HID specification) to have to
recompile kernel with CONFIG_HID_DEBUG to be able to see kernel's perspective
of the HID report descriptor and observe the parsed events. Plus the messages
are then mixed up inconveniently with the rest of the dmesg stuff.
This patch implements /sys/kernel/debug/hid/<device>/rdesc file, which
represents the kernel's view of report descriptor (both the raw report
descriptor data and parsed contents).
With all the device-specific debug data being available through debugfs, there
is no need for keeping CONFIG_HID_DEBUG, as the 'debug' parameter to the
hid module will now only output only driver-specific debugging options, which has
absolutely minimal memory footprint, just a few error messages and one global
flag (hid_debug).
We use the current set of output formatting functions. The ones that need to be
used both for one-shot rdesc seq_file and also for continuous flow of data
(individual reports, as being sent by the device) distinguish according to the
passed seq_file parameter, and if it is NULL, it still output to kernel ringbuffer,
otherwise the corresponding seq_file is used for output.
The format of the output is preserved.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Added constants to hid.h for all digitizer usages (including the new multitouch
ones that are not yet in the official USB spec but are being pushed by Microsft
as described in their paper "Digitizer Drivers for Windows Touch and Pen-Based
Computers"). Updated hid-debug.c to support the new MT input constants such as
ABS_MT_POSITION_X.
Signed-off-by: Stephane Chatty <chatty@enac.fr>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This patch removes CVS keywords that weren't updated for a long time
from comments.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Currently using debug=1 with hid module prints out all sent and received
reports to the kernel log, while in many cases we only want to see the
report descriptors and hid-input mappings that are printed when a device
is probed.
Add new level debug=2, and only dump the report traffic with that level.
Signed-off-by: Anssi Hannula <anssi.hannula@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
HUT 1.12 defines Logoff usage 0x19c in Consumer page. There are
keyboards out there emitting this usage code (for example Microsoft
Wireless Laser Keyboard 6000). Add this key so that HID code could
map usages to it.
Signed-off-by: Khelben Blackstaff <eye.of.the.8eholder@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
- added KERN_DEBUG to output lines
- fixed preffered -> preferred typo
- added const to char *'s
Also, exported symbol hid_resolv_event is unused by the current
kernel tree and perhaps should be removed.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This keyboard emits a few usages that are not handled properly by
hid-input.
The usages from MSVENDOR page are colliding with Chicony Tactical
Pad device, so we have to distinguish in runtime. Ugly ...
Also, the buttons 1-5 have to be handled in a non-standard way,
as they are emitted by the keyboard in a bitfield-like fashion, but
the field is not presented as bit-field by the keyboard. The keys can't
be pressed simultaneously, so the handling we have is correct.
This patch also extends hid_keyboard[] with KPLeftParenthesis and
KPRightParenthesis as defined by Keyboard page in HUT 1.12. The
corresponding usages are also emitted by this keyboard.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
There have been many reports recently about broken HID devices, the
diagnosis of which required users to recompile their kernels in order
to be able to provide debugging output needed for coding a quirk for
a particular device.
This patch makes CONFIG_HID_DEBUG default y if !EMBEDDED and makes it
possible to control debugging output produced by HID code by supplying
'debug=1' module parameter.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Every file should include the headers containing the prototypes for
it's global functions.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
CONFIG_INPUT_DEBUG is non-existent option, so remove anything depending
on it.
Also, as we have new CONFIG_HID_DEBUG, this should be used on places
where ifdef DEBUG was used before.
Suggested by Adrian Bunk.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
hid-debug.h contains a lot of code, and should not therefore
be a header.
This patch moves the code to generic hid layer as .c source, and
introduces CONFIG_HID_DEBUG to conditionally compile it, instead
of playing with #define DEBUG and including hid-debug.h.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Jiri Kosina
Arnd Bergmann
Chase Douglas
Julia Lawall
Daniel Mack
Tejun Heo
Bruno Prémont
H Hartley Sweeten
Stephane Chatty
Adrian Bunk
Anssi Hannula
Khelben Blackstaff
Joe Perches
Adrian Bunk