Commit Graph

34 Commits

Author SHA1 Message Date
Arnd Bergmann 6038f373a3 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>
2010-10-15 15:53:27 +02:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
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>
2010-03-30 22:02:32 +09:00
Ralf Baechle 8facefd090 MIPS: Don't include <linux/smp_lock.h> unnecessarily.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-02-27 12:52:57 +01:00
Ralf Baechle 1bbfc20d01 MIPS: VPE: Get rid of BKL.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-09-30 21:47:02 +02:00
Ralf Baechle 982f6ffeee MIPS: Remove useless zero initializations.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-09-17 20:07:51 +02:00
Greg Kroah-Hartman a9b12619f7 device create: misc: convert device_create_drvdata to device_create
Now that device_create() has been audited, rename things back to the
original call to be sane.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-16 09:24:43 -07:00
Greg Kroah-Hartman 43f98747d4 device create: mips: convert device_create to device_create_drvdata
device_create() is race-prone, so use the race-free
device_create_drvdata() instead as device_create() is going away.

Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-21 21:54:43 -07:00
Jonathan Corbet 7558da942e mips: cdev lock_kernel() pushdown
Push the cdev lock_kernel() call into MIPS-specific drivers.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2008-05-18 15:43:40 -06:00
Kevin D. Kissell 1928cc84a0 [MIPS] MT: Functional fixes and a little reformatting of APRP support
Signed-off-by: Kevin D. Kissell <kevink@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-05-12 16:46:51 +01:00
Lucas Woods adfb899866 [MIPS] Remove duplicate includes.
Signed-off-by: Lucas Woods <woodzy@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-01-29 10:14:56 +00:00
Ralf Baechle 4d24c8f955 [MIPS] rtlx: Fix build error.
CC      arch/mips/kernel/rtlx.o
cc1: warnings being treated as errors
arch/mips/kernel/rtlx.c:59: warning: 'irq' defined but not used
arch/mips/kernel/rtlx.c:60: warning: 'irq_num' defined but not used

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-09-14 19:08:42 +01:00
Ralf Baechle e606c109c4 [MIPS] rtlx: fix int vs. long bug.
CC      arch/mips/kernel/rtlx.o
arch/mips/kernel/rtlx.c: In function 'rtlx_init':
arch/mips/kernel/rtlx.c:114: warning: format '%x' expects type 'unsigned int', but argument 3 has type 'long unsigned int'

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-09-14 19:08:42 +01:00
Ralf Baechle 9d5a3f5fa3 [MIPS] rtlx: Fix modpost warning
WARNING: vmlinux.o(.text+0x11504): Section mismatch: reference to .init.data:register_chrdev_failed (between 'rtlx_module_init' and 'rtlx_dispatch')

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-07-31 21:35:26 +01:00
Ralf Baechle 07cc0c9e65 [MIPS] MT: Enable coexistence of AP/SP with VSMP and SMTC.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-07-31 21:35:24 +01:00
David Rientjes f5dbeaf5ed [MIPS] Replace __attribute_used__ with __used
Replaces the deprecated __attribute_used__ with __used.  Also makes some
style adjustments to abide by the kernel coding conventions.

Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-07-24 16:02:47 +01:00
Ralf Baechle 7f5a7716dc [MIPS] Fix AP/SP to work in the reality of modern kernels.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-04-27 16:20:23 +01:00
Ralf Baechle 46230aa6ea [MIPS] RTLX: Handle copy_*_user return values.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-03-17 01:03:29 +00:00
Ralf Baechle bc4809e939 [MIPS] RTLX: Protect rtlx_{read,write} with mutex.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-03-17 01:03:28 +00:00
Ralf Baechle 61dcc6f4d9 [MIPS] RTLX: Harden against compiler reordering and optimization.
RTLX communication is based on lock-free shared memory buffers.  It
happened to be working by luck so far but relies on the optimizer doing
certain optimizations but no reordering.

Fixed by inserting proper barriers in rtlx_read and rtlx_write, and careful
pointer dereferencing.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-03-17 01:03:27 +00:00
Ralf Baechle 9e34682026 [MIPS] RTLX: Don't use volatile; it's fragile.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-03-17 01:03:27 +00:00
Ralf Baechle 3dac2561e2 [MIPS] RTLX: Delete multiple definition of ret shaddowing each other.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-02-26 23:06:06 +00:00
Ralf Baechle c4c4018b04 [MIPS] RTLX, VPE: Make open actually atomic.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-02-26 23:06:06 +00:00
Ralf Baechle 67e2cccec6 [MIPS] RTLX: Handle signals when sleeping.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-02-26 23:06:05 +00:00
Arjan van de Ven 5dfe4c964a [PATCH] mark struct file_operations const 2
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.

[akpm@osdl.org: sparc64 fix]
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>
2007-02-12 09:48:44 -08:00
Ralf Baechle bb3d7c7ff1 [MIPS] RTLX: Sprinkle device model code into code to make udev happier.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-02-10 22:38:43 +00:00
Atsushi Nemoto 97dcb82de6 [MIPS] Define MIPS_CPU_IRQ_BASE in generic header
The irq_base for {mips,rm7k,rm9k}_cpu_irq_init() are constant on all
platforms and are same value on most platforms (0 or 16, depends on
CONFIG_I8259).  Define them in asm-mips/mach-generic/irq.h and make
them customizable.  This will save a few cycle on each CPU interrupt.

A good side effect is removing some dependencies to MALTA in generic
SMTC code.

Although MIPS_CPU_IRQ_BASE is customizable, this patch changes irq
mappings on DDB5477, EMMA2RH and MIPS_SIM, since really customizing
them might cause some header dependency problem and there seems no
good reason to customize it.  So currently only VR41XX is using custom
MIPS_CPU_IRQ_BASE value, which is 0 regardless of CONFIG_I8259.

Testing this patch on those platforms is greatly appreciated.  Thank
you.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-02-06 16:53:08 +00:00
Josef Sipek 1b04fe9a8e [PATCH] struct path: convert mips
Signed-off-by: Josef Sipek <jsipek@fsl.cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:47 -08:00
Ralf Baechle 937a801576 [MIPS] Complete fixes after removal of pt_regs argument to int handlers.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-08 02:38:28 +01:00
Thomas Gleixner f40298fddc [PATCH] irq-flags: MIPS: Use the new IRQF_ constants
Use the new IRQF_ constants and remove the SA_INTERRUPT define

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-02 13:58:47 -07:00
Ralf Baechle 79e55bcf24 [MIPS] Cleanup inode->r_dev usage.
imajor()/iminor() should be used instead of accessing r_dev directly.

Based on patch from Eric Sesterhenn (snakebyte@gmx.de).
    
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-04-27 15:13:50 +01:00
Ralf Baechle 2600990e64 [MIPS] kpsd and other AP/SP improvements.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-04-19 04:14:27 +02:00
Ralf Baechle a84c96e202 [MIPS] RTLX compile fixes.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-02-07 13:30:21 +00:00
Ralf Baechle afc4841d8a Turn rtlx upside down.
o Coding style
 o Race condition on open
 o Switch to dynamic major
 o Header file cleanup
    
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-11-07 18:05:33 +00:00
Ralf Baechle e01402b115 More AP / SP bits for the 34K, the Malta bits and things. Still wants
a little polishing.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-10-29 19:31:53 +01:00