From 345ee8392dc149ca529f80e40583928977ad592e Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Wed, 14 Nov 2007 23:39:42 +0100 Subject: [PATCH 1/6] allow LEGACY_PTYS to be set to 0 The count of legacy pty devices can be set by a kernel commandline parameter. For the distro kernel, we would like to disable all pty's by default, but keep the opportunity to request devices on the kernel commandline. Signed-off-by: Kay Sievers Acked-by: Jean Delvare Signed-off-by: Greg Kroah-Hartman --- drivers/char/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index bf18d757b876..a509b8d79781 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -457,7 +457,7 @@ config LEGACY_PTYS config LEGACY_PTY_COUNT int "Maximum number of legacy PTY in use" depends on LEGACY_PTYS - range 1 256 + range 0 256 default "256" ---help--- The maximum number of legacy PTYs that can be used at any one time. From dec13c15445fec29ca9087890895718450e80b95 Mon Sep 17 00:00:00 2001 From: Daniel Drake Date: Wed, 21 Nov 2007 14:55:18 -0800 Subject: [PATCH 2/6] create /sys/.../power when CONFIG_PM is set The CONFIG_SUSPEND changes in 2.6.23 caused a regression under certain configuration conditions (SUSPEND=n, USB_AUTOSUSPEND=y) where all USB device attributes in sysfs (idVendor, idProduct, ...) silently disappeared, causing udev breakage and more. The cause of this is that the /sys/.../power subdirectory is now only created when CONFIG_PM_SLEEP is set, however, it should be created whenever CONFIG_PM is set to handle the above situation. The following patch fixes the regression. Signed-off-by: Daniel Drake Acked-by: Rafael J. Wysocki Cc: Alan Stern Cc: Kay Sievers Cc: stable Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- drivers/base/core.c | 4 +++- drivers/base/power/Makefile | 3 ++- drivers/base/power/main.c | 8 +------- drivers/base/power/power.h | 28 +++++++++++++++++++++------- 4 files changed, 27 insertions(+), 16 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index 3f4d6aa13990..2683eac30c68 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -770,9 +770,10 @@ int device_add(struct device *dev) error = device_add_attrs(dev); if (error) goto AttrsError; - error = device_pm_add(dev); + error = dpm_sysfs_add(dev); if (error) goto PMError; + device_pm_add(dev); error = bus_add_device(dev); if (error) goto BusError; @@ -797,6 +798,7 @@ int device_add(struct device *dev) return error; BusError: device_pm_remove(dev); + dpm_sysfs_remove(dev); PMError: if (dev->bus) blocking_notifier_call_chain(&dev->bus->bus_notifier, diff --git a/drivers/base/power/Makefile b/drivers/base/power/Makefile index a803733c839e..44504e6618fb 100644 --- a/drivers/base/power/Makefile +++ b/drivers/base/power/Makefile @@ -1,5 +1,6 @@ obj-y := shutdown.o -obj-$(CONFIG_PM_SLEEP) += main.o sysfs.o +obj-$(CONFIG_PM) += sysfs.o +obj-$(CONFIG_PM_SLEEP) += main.o obj-$(CONFIG_PM_TRACE) += trace.o ifeq ($(CONFIG_DEBUG_DRIVER),y) diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 0ab4ab21f564..691ffb64cc37 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -38,20 +38,14 @@ static DEFINE_MUTEX(dpm_list_mtx); int (*platform_enable_wakeup)(struct device *dev, int is_on); -int device_pm_add(struct device *dev) +void device_pm_add(struct device *dev) { - int error; - pr_debug("PM: Adding info for %s:%s\n", dev->bus ? dev->bus->name : "No Bus", kobject_name(&dev->kobj)); mutex_lock(&dpm_list_mtx); list_add_tail(&dev->power.entry, &dpm_active); - error = dpm_sysfs_add(dev); - if (error) - list_del(&dev->power.entry); mutex_unlock(&dpm_list_mtx); - return error; } void device_pm_remove(struct device *dev) diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h index 5c4efd493fa5..379da4e958e0 100644 --- a/drivers/base/power/power.h +++ b/drivers/base/power/power.h @@ -13,14 +13,29 @@ extern void device_shutdown(void); extern struct list_head dpm_active; /* The active device list */ -static inline struct device * to_device(struct list_head * entry) +static inline struct device *to_device(struct list_head *entry) { return container_of(entry, struct device, power.entry); } -extern int device_pm_add(struct device *); +extern void device_pm_add(struct device *); extern void device_pm_remove(struct device *); +#else /* CONFIG_PM_SLEEP */ + + +static inline void device_pm_add(struct device *dev) +{ +} + +static inline void device_pm_remove(struct device *dev) +{ +} + +#endif + +#ifdef CONFIG_PM + /* * sysfs.c */ @@ -28,16 +43,15 @@ extern void device_pm_remove(struct device *); extern int dpm_sysfs_add(struct device *); extern void dpm_sysfs_remove(struct device *); -#else /* CONFIG_PM_SLEEP */ +#else /* CONFIG_PM */ - -static inline int device_pm_add(struct device * dev) +static inline int dpm_sysfs_add(struct device *dev) { return 0; } -static inline void device_pm_remove(struct device * dev) -{ +static inline void dpm_sysfs_remove(struct device *dev) +{ } #endif From ed423c24a8f749e2d6207128a91c724f2f7d82ce Mon Sep 17 00:00:00 2001 From: Hans J Koch Date: Mon, 26 Nov 2007 22:03:29 +0100 Subject: [PATCH 3/6] UIO: fix up the UIO documentation Remove references to the old uio_dummy demo module from UIO documentation. Add a small paragraph to make it clearer that UIO is not a universal driver interface. Signed-off-by: Hans J Koch Signed-off-by: Greg Kroah-Hartman --- Documentation/DocBook/uio-howto.tmpl | 90 ++++++++++------------------ 1 file changed, 32 insertions(+), 58 deletions(-) diff --git a/Documentation/DocBook/uio-howto.tmpl b/Documentation/DocBook/uio-howto.tmpl index c119484258b8..fdd7f4f887b7 100644 --- a/Documentation/DocBook/uio-howto.tmpl +++ b/Documentation/DocBook/uio-howto.tmpl @@ -29,6 +29,12 @@ + + 0.4 + 2007-11-26 + hjk + Removed section about uio_dummy. + 0.3 2007-04-29 @@ -94,6 +100,26 @@ interested in translating it, please email me user space. This simplifies development and reduces the risk of serious bugs within a kernel module. + + Please note that UIO is not an universal driver interface. Devices + that are already handled well by other kernel subsystems (like + networking or serial or USB) are no candidates for an UIO driver. + Hardware that is ideally suited for an UIO driver fulfills all of + the following: + + + + The device has memory that can be mapped. The device can be + controlled completely by writing to this memory. + + + The device usually generates interrupts. + + + The device does not fit into one of the standard kernel + subsystems. + + @@ -174,8 +200,9 @@ interested in translating it, please email me For cards that don't generate interrupts but need to be polled, there is the possibility to set up a timer that triggers the interrupt handler at configurable time intervals. - See drivers/uio/uio_dummy.c for an - example of this technique. + This interrupt simulation is done by calling + uio_event_notify() + from the timer's event handler. @@ -263,63 +290,11 @@ offset = N * getpagesize(); - - -Using uio_dummy - - Well, there is no real use for uio_dummy. Its only purpose is - to test most parts of the UIO system (everything except - hardware interrupts), and to serve as an example for the - kernel module that you will have to write yourself. - - - -What uio_dummy does - - The kernel module uio_dummy.ko creates a - device that uses a timer to generate periodic interrupts. The - interrupt handler does nothing but increment a counter. The - driver adds two custom attributes, count - and freq, that appear under - /sys/devices/platform/uio_dummy/. - - - - The attribute count can be read and - written. The associated file - /sys/devices/platform/uio_dummy/count - appears as a normal text file and contains the total number of - timer interrupts. If you look at it (e.g. using - cat), you'll notice it is slowly counting - up. - - - - The attribute freq can be read and written. - The content of - /sys/devices/platform/uio_dummy/freq - represents the number of system timer ticks between two timer - interrupts. The default value of freq is - the value of the kernel variable HZ, which - gives you an interval of one second. Lower values will - increase the frequency. Try the following: - - -cd /sys/devices/platform/uio_dummy/ -echo 100 > freq - - - Use cat count to see how the interrupt - frequency changes. - - - - Writing your own kernel module - Please have a look at uio_dummy.c as an + Please have a look at uio_cif.c as an example. The following paragraphs explain the different sections of this file. @@ -354,9 +329,8 @@ See the description below for details. interrupt, it's your modules task to determine the irq number during initialization. If you don't have a hardware generated interrupt but want to trigger the interrupt handler in some other way, set -irq to UIO_IRQ_CUSTOM. The -uio_dummy module does this as it triggers the event mechanism in a timer -routine. If you had no interrupt at all, you could set +irq to UIO_IRQ_CUSTOM. +If you had no interrupt at all, you could set irq to UIO_IRQ_NONE, though this rarely makes sense. From 1f4ebbbf188805036afc915eb759f4b294815857 Mon Sep 17 00:00:00 2001 From: Hans J Koch Date: Mon, 26 Nov 2007 22:10:35 +0100 Subject: [PATCH 4/6] UIO: add UIO documentation target to DocBook Makefile Add the DocBook documentation for the Userspace I/O framework to the Makefile. Signed-off-by: Satoru Takeuchi Signed-off-by: Hans J Koch Signed-off-by: Greg Kroah-Hartman --- Documentation/DocBook/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile index 054a7ecf64c6..4953bc258729 100644 --- a/Documentation/DocBook/Makefile +++ b/Documentation/DocBook/Makefile @@ -11,7 +11,7 @@ DOCBOOKS := wanbook.xml z8530book.xml mcabook.xml videobook.xml \ procfs-guide.xml writing_usb_driver.xml \ kernel-api.xml filesystems.xml lsm.xml usb.xml \ gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \ - genericirq.xml s390-drivers.xml + genericirq.xml s390-drivers.xml uio-howto.xml ### # The build process is as follows (targets): From 71409a498e96a421bdc20e7275ebc4fab8b14cdc Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Mon, 5 Nov 2007 13:59:11 +0100 Subject: [PATCH 5/6] kobject: two typo fixes This fixes two typos from commit 34358c26a2c96b2a068dc44e0ac602106a466bce. Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- lib/kobject.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/kobject.c b/lib/kobject.c index a7e3bf4d3c70..b52e9f4ef371 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -313,8 +313,8 @@ int kobject_rename(struct kobject * kobj, const char *new_name) struct kobject *temp_kobj; temp_kobj = kset_find_obj(kobj->kset, new_name); if (temp_kobj) { - printk(KERN_WARNING "kobject '%s' can not be renamed " - "to '%s' as '%s' is already in existance.\n", + printk(KERN_WARNING "kobject '%s' cannot be renamed " + "to '%s' as '%s' is already in existence.\n", kobject_name(kobj), new_name, new_name); kobject_put(temp_kobj); return -EINVAL; From 8118a859dc7abd873193986c77a8d9bdb877adc8 Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Wed, 21 Nov 2007 14:55:19 -0800 Subject: [PATCH 6/6] sysfs: fix off-by-one error in fill_read_buffer() I found that there is a off-by-one problem in the following code. Version: 2.6.24-rc2 File: fs/sysfs/file.c:118-122 Function: fill_read_buffer -------------------------------------------------------------------- count = ops->show(kobj, attr_sd->s_attr.attr, buffer->page); sysfs_put_active_two(attr_sd); BUG_ON(count > (ssize_t)PAGE_SIZE); -------------------------------------------------------------------- Because according to the specification of the sysfs and the implement of the show methods, the show methods return the number of bytes which would be generated for the given input, excluding the trailing null.So if the return value of the show methods equals PAGE_SIZE - 1, the buffer is full in fact. And if the return value equals PAGE_SIZE, the resulting string was already truncated,or buffer overflow occurred. This patch fixes an off-by-one error in fill_read_buffer. Signed-off-by: Miao Xie Signed-off-by: Andrew Morton Acked-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 27d1785b7644..4045bdcc4b33 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -119,7 +119,11 @@ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer sysfs_put_active_two(attr_sd); - BUG_ON(count > (ssize_t)PAGE_SIZE); + /* + * The code works fine with PAGE_SIZE return but it's likely to + * indicate truncated result or overflow in normal use cases. + */ + BUG_ON(count >= (ssize_t)PAGE_SIZE); if (count >= 0) { buffer->needs_read_fill = 0; buffer->count = count;