The patch titled
saa7134-tvaudio: convert to kthread API
has been added to the -mm tree. Its filename is
mm-only-saa7134-tvaudio-convert-to-kthread-api.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: saa7134-tvaudio: convert to kthread API
From: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
It is my goal to replace all kernel code that handles signals from user
space, calls kernel_thread or calls daemonize. All of which the
kthread_api makes unncessary. Handling signals from user space is a
maintenance problem becuase using a kernel thread is an implementation
detail and if user space cares it does not allow us to change the
implementation. Calling daemonize is a problem because it has to undo a
continually changing set of state generated by user space, requiring the
implemetation to change continually. kernel_thread is a problem because it
returns a pid_t value. Numeric pids are inherently racy and in the
presence of a pid namespace they are no longer global making them useless
for general use in the kernel.
So this patch renames the pid member of struct saa7134_thread started and
changes it's type from pid_t to int. All it has ever been used for is to
detect if the kernel thread is has been started so this works.
allow_signal(SIGTERM) and the calls to signal_pending have been removed
they are needed for the driver to operation.
The startup of tvaudio_thread and tvaudio_thread_dep have been modified to
use kthread_run instead of a combination of kernel_thread and daemonize.
The result is code that is slightly simpler and more maintainable.
Cc: Hartmut Hackmann <hartmut.hackmann@xxxxxxxxxxx>
Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxx>
Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/media/video/saa7134/saa7134-tvaudio.c | 27 +++++++---------
drivers/media/video/saa7134/saa7134.h | 2 -
2 files changed, 14 insertions(+), 15 deletions(-)
diff -puN drivers/media/video/saa7134/saa7134-tvaudio.c~mm-only-saa7134-tvaudio-convert-to-kthread-api drivers/media/video/saa7134/saa7134-tvaudio.c
--- a/drivers/media/video/saa7134/saa7134-tvaudio.c~mm-only-saa7134-tvaudio-convert-to-kthread-api
+++ a/drivers/media/video/saa7134/saa7134-tvaudio.c
@@ -27,6 +27,7 @@
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/delay.h>
+#include <linux/kthread.h>
#include <asm/div64.h>
#include "saa7134-reg.h"
@@ -505,11 +506,9 @@ static int tvaudio_thread(void *data)
unsigned int i, audio, nscan;
int max1,max2,carrier,rx,mode,lastmode,default_carrier;
- daemonize("%s", dev->name);
- allow_signal(SIGTERM);
for (;;) {
tvaudio_sleep(dev,-1);
- if (dev->thread.shutdown || signal_pending(current))
+ if (dev->thread.shutdown)
goto done;
restart:
@@ -618,7 +617,7 @@ static int tvaudio_thread(void *data)
for (;;) {
if (tvaudio_sleep(dev,5000))
goto restart;
- if (dev->thread.shutdown || signal_pending(current))
+ if (dev->thread.shutdown)
break;
if (UNSET == dev->thread.mode) {
rx = tvaudio_getstereo(dev,&tvaudio[i]);
@@ -782,9 +781,6 @@ static int tvaudio_thread_ddep(void *dat
struct saa7134_dev *dev = data;
u32 value, norms, clock;
- daemonize("%s", dev->name);
- allow_signal(SIGTERM);
-
clock = saa7134_boards[dev->board].audio_clock;
if (UNSET != audio_clock_override)
clock = audio_clock_override;
@@ -796,7 +792,7 @@ static int tvaudio_thread_ddep(void *dat
for (;;) {
tvaudio_sleep(dev,-1);
- if (dev->thread.shutdown || signal_pending(current))
+ if (dev->thread.shutdown)
goto done;
restart:
@@ -986,14 +982,17 @@ int saa7134_tvaudio_init2(struct saa7134
break;
}
- dev->thread.pid = -1;
+ dev->thread.started = 0;
if (my_thread) {
+ struct task_struct *task;
/* start tvaudio thread */
init_waitqueue_head(&dev->thread.wq);
init_completion(&dev->thread.exit);
- dev->thread.pid = kernel_thread(my_thread,dev,0);
- if (dev->thread.pid < 0)
- printk(KERN_WARNING "%s: kernel_thread() failed\n",
+ task = kthread_run(my_thread, dev, "%s", dev->name);
+ if (!IS_ERR(task))
+ dev->thread.started = 1;
+ else
+ printk(KERN_WARNING "%s: kthread_create() failed\n",
dev->name);
saa7134_tvaudio_do_scan(dev);
}
@@ -1005,7 +1004,7 @@ int saa7134_tvaudio_init2(struct saa7134
int saa7134_tvaudio_fini(struct saa7134_dev *dev)
{
/* shutdown tvaudio thread */
- if (dev->thread.pid >= 0) {
+ if (dev->thread.started) {
dev->thread.shutdown = 1;
wake_up_interruptible(&dev->thread.wq);
wait_for_completion(&dev->thread.exit);
@@ -1020,7 +1019,7 @@ int saa7134_tvaudio_do_scan(struct saa71
dprintk("sound IF not in use, skipping scan\n");
dev->automute = 0;
saa7134_tvaudio_setmute(dev);
- } else if (dev->thread.pid >= 0) {
+ } else if (dev->thread.started) {
dev->thread.mode = UNSET;
dev->thread.scan2++;
wake_up_interruptible(&dev->thread.wq);
diff -puN drivers/media/video/saa7134/saa7134.h~mm-only-saa7134-tvaudio-convert-to-kthread-api drivers/media/video/saa7134/saa7134.h
--- a/drivers/media/video/saa7134/saa7134.h~mm-only-saa7134-tvaudio-convert-to-kthread-api
+++ a/drivers/media/video/saa7134/saa7134.h
@@ -324,7 +324,7 @@ struct saa7134_pgtable {
/* tvaudio thread status */
struct saa7134_thread {
- pid_t pid;
+ int started;
struct completion exit;
wait_queue_head_t wq;
unsigned int shutdown;
_
Patches currently in -mm which might be from ebiederm@xxxxxxxxxxxx are
powerpc-rtas-msi-support.patch
mm-only-dvb_en_50221-convert-to-kthread-api.patch
mm-only-saa7134-tvaudio-convert-to-kthread-api.patch
fix-i-oat-for-kexec.patch
i386-irq-kill-irq-compression.patch
i386-map-enough-initial-memory-to-create-lowmem-mappings.patch
i386-map-enough-initial-memory-to-create-lowmem-mappings-fix.patch
clone-flag-clone_parent_tidptr-leaves-invalid-results-in-memory.patch
allow-access-to-proc-pid-fd-after-setuid.patch
merge-sys_clone-sys_unshare-nsproxy-and-namespace.patch
fix-race-between-proc_get_inode-and-remove_proc_entry.patch
fix-race-between-proc_readdir-and-remove_proc_entry.patch
procfs-reorder-struct-pid_dentry-to-save-space-on-64bit-archs-and-constify-them.patch
tty-remove-unnecessary-export-of-proc_clear_tty.patch
tty-simplify-calling-of-put_pid.patch
tty-introduce-no_tty-and-use-it-in-selinux.patch
tty-in-tiocsctty-when-we-steal-a-tty-hang-it-up.patch
tty-in-tiocsctty-when-we-steal-a-tty-hang-it-up-fix.patch
clean-up-elf-note-generation.patch
remove-hardcoding-of-hard_smp_processor_id-on-up.patch
use-the-apic-to-determine-the-hardware-processor-id-i386.patch
use-the-apic-to-determine-the-hardware-processor-id-x86_64.patch
always-ask-the-hardware-to-obtain-hardware-processor-id-ia64.patch
proc-cleanup-use-seq_release_private-where-appropriate.patch
smbfs-remove-unnecessary-allow_signal.patch
kthread-dont-depend-on-work-queues-take-2.patch
kthread-dont-depend-on-work-queues-take-2-fix.patch
change-reparent_to_init-to-reparent_to_kthreadd.patch
wait_for_helper-remove-unneeded-do_sigaction.patch
worker_thread-dont-play-with-sigchld-and-numa-policy.patch
change-kernel-threads-to-ignore-signals-instead-of-blocking-them.patch
fix-kthread_create-vs-freezer-theoretical-race.patch
edac-k8-driver-coding-tidy.patch
nfsd-nfs4state-remove-unnecessary-daemonize-call.patch
statically-initialize-struct-pid-for-swapper.patch
explicitly-set-pgid-and-sid-of-init-process.patch
use-struct-pid-parameter-in-copy_process.patch
use-task_pgrp-task_session-in-copy_process.patch
kill-unused-sesssion-and-group-values-in-rocket-driver.patch
fix-some-coding-style-errors-in-autofs.patch
replace-pid_t-in-autofs-with-struct-pid-reference.patch
dont-init-pgrp-and-__session-in-init_signals.patch
md-remove-broken-sigkill-support.patch
mutex-subsystem-synchro-test-module-convert-to-the-kthread-api.patch
vdso-print-fatal-signals-use-ctl_unnumbered.patch
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