Re: [PATCH 2/5] driver core: make struct class.devnode() take a const *

Sumit Semwal
2022-11-25T12:41:16Z

Hello Greg,

On Fri, 25 Nov 2022 at 17:25, Mauro Carvalho Chehab <mchehab@kernel.org> wrote:
>
> Em Wed, 23 Nov 2022 13:25:20 +0100
> Greg Kroah-Hartman <gregkh@linuxfoundation.org> escreveu:
>
> > The devnode() in struct class should not be modifying the device that is
> > passed into it, so mark it as a const * and propagate the function
> > signature changes out into all relevant subsystems that use this
> > callback.
>
> Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org>
> >
Please feel free to add my
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
for the dma-buf portion.

Best,
Sumit.
> > Cc: Fenghua Yu <fenghua.yu@intel.com>
> > Cc: Reinette Chatre <reinette.chatre@intel.com>
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > Cc: Ingo Molnar <mingo@redhat.com>
> > Cc: Borislav Petkov <bp@alien8.de>
> > Cc: Dave Hansen <dave.hansen@linux.intel.com>
> > Cc: x86@kernel.org
> > Cc: "H. Peter Anvin" <hpa@zytor.com>
> > Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
> > Cc: Jens Axboe <axboe@kernel.dk>
> > Cc: Justin Sanders <justin@coraid.com>
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > Cc: Sumit Semwal <sumit.semwal@linaro.org>
> > Cc: Benjamin Gaignard <benjamin.gaignard@collabora.com>
> > Cc: Liam Mark <lmark@codeaurora.org>
> > Cc: Laura Abbott <labbott@redhat.com>
> > Cc: Brian Starkey <Brian.Starkey@arm.com>
> > Cc: John Stultz <jstultz@google.com>
> > Cc: "Christian König" <christian.koenig@amd.com>
> > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> > Cc: Maxime Ripard <mripard@kernel.org>
> > Cc: Thomas Zimmermann <tzimmermann@suse.de>
> > Cc: David Airlie <airlied@gmail.com>
> > Cc: Daniel Vetter <daniel@ffwll.ch>
> > Cc: Jason Gunthorpe <jgg@ziepe.ca>
> > Cc: Leon Romanovsky <leon@kernel.org>
> > Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
> > Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> > Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
> > Cc: Sean Young <sean@mess.org>
> > Cc: Frank Haverkamp <haver@linux.ibm.com>
> > Cc: Jiri Slaby <jirislaby@kernel.org>
> > Cc: "Michael S. Tsirkin" <mst@redhat.com>
> > Cc: Jason Wang <jasowang@redhat.com>
> > Cc: Alex Williamson <alex.williamson@redhat.com>
> > Cc: Cornelia Huck <cohuck@redhat.com>
> > Cc: Kees Cook <keescook@chromium.org>
> > Cc: Anton Vorontsov <anton@enomsg.org>
> > Cc: Colin Cross <ccross@android.com>
> > Cc: Tony Luck <tony.luck@intel.com>
> > Cc: Jaroslav Kysela <perex@perex.cz>
> > Cc: Takashi Iwai <tiwai@suse.com>
> > Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
> > Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> > Cc: Xie Yongji <xieyongji@bytedance.com>
> > Cc: Gautam Dawar <gautam.dawar@xilinx.com>
> > Cc: Dan Carpenter <error27@gmail.com>
> > Cc: Eli Cohen <elic@nvidia.com>
> > Cc: Parav Pandit <parav@nvidia.com>
> > Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
> > Cc: alsa-devel@alsa-project.org
> > Cc: dri-devel@lists.freedesktop.org
> > Cc: kvm@vger.kernel.org
> > Cc: linaro-mm-sig@lists.linaro.org
> > Cc: linux-block@vger.kernel.org
> > Cc: linux-input@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > Cc: linux-media@vger.kernel.org
> > Cc: linux-rdma@vger.kernel.org
> > Cc: linux-scsi@vger.kernel.org
> > Cc: linux-usb@vger.kernel.org
> > Cc: virtualization@lists.linux-foundation.org
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > ---
> > arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 4 ++--
> > arch/x86/kernel/cpuid.c | 2 +-
> > arch/x86/kernel/msr.c | 2 +-
> > block/bsg.c | 2 +-
> > drivers/block/aoe/aoechr.c | 2 +-
> > drivers/char/mem.c | 2 +-
> > drivers/char/misc.c | 4 ++--
> > drivers/dma-buf/dma-heap.c | 2 +-
> > drivers/gpu/drm/drm_sysfs.c | 2 +-
> > drivers/infiniband/core/user_mad.c | 2 +-
> > drivers/infiniband/core/uverbs_main.c | 2 +-
> > drivers/infiniband/hw/hfi1/device.c | 4 ++--
> > drivers/input/input.c | 2 +-
> > drivers/media/dvb-core/dvbdev.c | 4 ++--
> > drivers/media/pci/ddbridge/ddbridge-core.c | 4 ++--
> > drivers/media/rc/rc-main.c | 2 +-
> > drivers/misc/genwqe/card_base.c | 2 +-
> > drivers/tty/tty_io.c | 2 +-
> > drivers/usb/core/file.c | 2 +-
> > drivers/vdpa/vdpa_user/vduse_dev.c | 2 +-
> > drivers/vfio/vfio_main.c | 2 +-
> > fs/pstore/pmsg.c | 2 +-
> > include/linux/device/class.h | 2 +-
> > sound/sound_core.c | 2 +-
> > 24 files changed, 29 insertions(+), 29 deletions(-)
> >
> > diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
> > index d961ae3ed96e..4e4231a58f38 100644
> > --- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
> > +++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
> > @@ -1560,9 +1560,9 @@ static const struct file_operations pseudo_lock_dev_fops = {
> > .mmap = pseudo_lock_dev_mmap,
> > };
> >
> > -static char *pseudo_lock_devnode(struct device *dev, umode_t *mode)
> > +static char *pseudo_lock_devnode(const struct device *dev, umode_t *mode)
> > {
> > - struct rdtgroup *rdtgrp;
> > + const struct rdtgroup *rdtgrp;
> >
> > rdtgrp = dev_get_drvdata(dev);
> > if (mode)
> > diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c
> > index 6f7b8cc1bc9f..621ba9c0f17a 100644
> > --- a/arch/x86/kernel/cpuid.c
> > +++ b/arch/x86/kernel/cpuid.c
> > @@ -139,7 +139,7 @@ static int cpuid_device_destroy(unsigned int cpu)
> > return 0;
> > }
> >
> > -static char *cpuid_devnode(struct device *dev, umode_t *mode)
> > +static char *cpuid_devnode(const struct device *dev, umode_t *mode)
> > {
> > return kasprintf(GFP_KERNEL, "cpu/%u/cpuid", MINOR(dev->devt));
> > }
> > diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c
> > index ed8ac6bcbafb..708751311786 100644
> > --- a/arch/x86/kernel/msr.c
> > +++ b/arch/x86/kernel/msr.c
> > @@ -250,7 +250,7 @@ static int msr_device_destroy(unsigned int cpu)
> > return 0;
> > }
> >
> > -static char *msr_devnode(struct device *dev, umode_t *mode)
> > +static char *msr_devnode(const struct device *dev, umode_t *mode)
> > {
> > return kasprintf(GFP_KERNEL, "cpu/%u/msr", MINOR(dev->devt));
> > }
> > diff --git a/block/bsg.c b/block/bsg.c
> > index 2ab1351eb082..08046bd9207d 100644
> > --- a/block/bsg.c
> > +++ b/block/bsg.c
> > @@ -232,7 +232,7 @@ struct bsg_device *bsg_register_queue(struct request_queue *q,
> > }
> > EXPORT_SYMBOL_GPL(bsg_register_queue);
> >
> > -static char *bsg_devnode(struct device *dev, umode_t *mode)
> > +static char *bsg_devnode(const struct device *dev, umode_t *mode)
> > {
> > return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev));
> > }
> > diff --git a/drivers/block/aoe/aoechr.c b/drivers/block/aoe/aoechr.c
> > index 8eea2529da20..7a368c90467d 100644
> > --- a/drivers/block/aoe/aoechr.c
> > +++ b/drivers/block/aoe/aoechr.c
> > @@ -273,7 +273,7 @@ static const struct file_operations aoe_fops = {
> > .llseek = noop_llseek,
> > };
> >
> > -static char *aoe_devnode(struct device *dev, umode_t *mode)
> > +static char *aoe_devnode(const struct device *dev, umode_t *mode)
> > {
> > return kasprintf(GFP_KERNEL, "etherd/%s", dev_name(dev));
> > }
> > diff --git a/drivers/char/mem.c b/drivers/char/mem.c
> > index 5611d127363e..83bf2a4dcb57 100644
> > --- a/drivers/char/mem.c
> > +++ b/drivers/char/mem.c
> > @@ -746,7 +746,7 @@ static const struct file_operations memory_fops = {
> > .llseek = noop_llseek,
> > };
> >
> > -static char *mem_devnode(struct device *dev, umode_t *mode)
> > +static char *mem_devnode(const struct device *dev, umode_t *mode)
> > {
> > if (mode && devlist[MINOR(dev->devt)].mode)
> > *mode = devlist[MINOR(dev->devt)].mode;
> > diff --git a/drivers/char/misc.c b/drivers/char/misc.c
> > index cba19bfdc44d..88c6995b9a3d 100644
> > --- a/drivers/char/misc.c
> > +++ b/drivers/char/misc.c
> > @@ -254,9 +254,9 @@ void misc_deregister(struct miscdevice *misc)
> > }
> > EXPORT_SYMBOL(misc_deregister);
> >
> > -static char *misc_devnode(struct device *dev, umode_t *mode)
> > +static char *misc_devnode(const struct device *dev, umode_t *mode)
> > {
> > - struct miscdevice *c = dev_get_drvdata(dev);
> > + const struct miscdevice *c = dev_get_drvdata(dev);
> >
> > if (mode && c->mode)
> > *mode = c->mode;
> > diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c
> > index 8f5848aa144f..4d7150791315 100644
> > --- a/drivers/dma-buf/dma-heap.c
> > +++ b/drivers/dma-buf/dma-heap.c
> > @@ -299,7 +299,7 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info)
> > return err_ret;
> > }
> >
> > -static char *dma_heap_devnode(struct device *dev, umode_t *mode)
> > +static char *dma_heap_devnode(const struct device *dev, umode_t *mode)
> > {
> > return kasprintf(GFP_KERNEL, "dma_heap/%s", dev_name(dev));
> > }
> > diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
> > index 430e00b16eec..14bf156b3f1b 100644
> > --- a/drivers/gpu/drm/drm_sysfs.c
> > +++ b/drivers/gpu/drm/drm_sysfs.c
> > @@ -90,7 +90,7 @@ static void drm_sysfs_acpi_register(void) { }
> > static void drm_sysfs_acpi_unregister(void) { }
> > #endif
> >
> > -static char *drm_devnode(struct device *dev, umode_t *mode)
> > +static char *drm_devnode(const struct device *dev, umode_t *mode)
> > {
> > return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
> > }
> > diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
> > index 98cb594cd9a6..f83954180a33 100644
> > --- a/drivers/infiniband/core/user_mad.c
> > +++ b/drivers/infiniband/core/user_mad.c
> > @@ -1224,7 +1224,7 @@ static struct attribute *umad_class_dev_attrs[] = {
> > };
> > ATTRIBUTE_GROUPS(umad_class_dev);
> >
> > -static char *umad_devnode(struct device *dev, umode_t *mode)
> > +static char *umad_devnode(const struct device *dev, umode_t *mode)
> > {
> > return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
> > }
> > diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
> > index d54434088727..bdb179a09d77 100644
> > --- a/drivers/infiniband/core/uverbs_main.c
> > +++ b/drivers/infiniband/core/uverbs_main.c
> > @@ -1237,7 +1237,7 @@ static void ib_uverbs_remove_one(struct ib_device *device, void *client_data)
> > put_device(&uverbs_dev->dev);
> > }
> >
> > -static char *uverbs_devnode(struct device *dev, umode_t *mode)
> > +static char *uverbs_devnode(const struct device *dev, umode_t *mode)
> > {
> > if (mode)
> > *mode = 0666;
> > diff --git a/drivers/infiniband/hw/hfi1/device.c b/drivers/infiniband/hw/hfi1/device.c
> > index 8ceff7141baf..1f4496032170 100644
> > --- a/drivers/infiniband/hw/hfi1/device.c
> > +++ b/drivers/infiniband/hw/hfi1/device.c
> > @@ -72,7 +72,7 @@ const char *class_name(void)
> > return hfi1_class_name;
> > }
> >
> > -static char *hfi1_devnode(struct device *dev, umode_t *mode)
> > +static char *hfi1_devnode(const struct device *dev, umode_t *mode)
> > {
> > if (mode)
> > *mode = 0600;
> > @@ -85,7 +85,7 @@ static const char *class_name_user(void)
> > return hfi1_class_name_user;
> > }
> >
> > -static char *hfi1_user_devnode(struct device *dev, umode_t *mode)
> > +static char *hfi1_user_devnode(const struct device *dev, umode_t *mode)
> > {
> > if (mode)
> > *mode = 0666;
> > diff --git a/drivers/input/input.c b/drivers/input/input.c
> > index ebb2b7f0f8ff..50597165dc54 100644
> > --- a/drivers/input/input.c
> > +++ b/drivers/input/input.c
> > @@ -1913,7 +1913,7 @@ static const struct device_type input_dev_type = {
> > #endif
> > };
> >
> > -static char *input_devnode(struct device *dev, umode_t *mode)
> > +static char *input_devnode(const struct device *dev, umode_t *mode)
> > {
> > return kasprintf(GFP_KERNEL, "input/%s", dev_name(dev));
> > }
> > diff --git a/drivers/media/dvb-core/dvbdev.c b/drivers/media/dvb-core/dvbdev.c
> > index 6ef18bab9648..e73f5240cc2c 100644
> > --- a/drivers/media/dvb-core/dvbdev.c
> > +++ b/drivers/media/dvb-core/dvbdev.c
> > @@ -1018,9 +1018,9 @@ static int dvb_uevent(const struct device *dev, struct kobj_uevent_env *env)
> > return 0;
> > }
> >
> > -static char *dvb_devnode(struct device *dev, umode_t *mode)
> > +static char *dvb_devnode(const struct device *dev, umode_t *mode)
> > {
> > - struct dvb_device *dvbdev = dev_get_drvdata(dev);
> > + const struct dvb_device *dvbdev = dev_get_drvdata(dev);
> >
> > return kasprintf(GFP_KERNEL, "dvb/adapter%d/%s%d",
> > dvbdev->adapter->num, dnames[dvbdev->type], dvbdev->id);
> > diff --git a/drivers/media/pci/ddbridge/ddbridge-core.c b/drivers/media/pci/ddbridge/ddbridge-core.c
> > index fe833f39698a..ee8087f29b2c 100644
> > --- a/drivers/media/pci/ddbridge/ddbridge-core.c
> > +++ b/drivers/media/pci/ddbridge/ddbridge-core.c
> > @@ -2716,9 +2716,9 @@ static const struct file_operations ddb_fops = {
> > .release = ddb_release,
> > };
> >
> > -static char *ddb_devnode(struct device *device, umode_t *mode)
> > +static char *ddb_devnode(const struct device *device, umode_t *mode)
> > {
> > - struct ddb *dev = dev_get_drvdata(device);
> > + const struct ddb *dev = dev_get_drvdata(device);
> >
> > return kasprintf(GFP_KERNEL, "ddbridge/card%d", dev->nr);
> > }
> > diff --git a/drivers/media/rc/rc-main.c b/drivers/media/rc/rc-main.c
> > index eba0cd30e314..527d9324742b 100644
> > --- a/drivers/media/rc/rc-main.c
> > +++ b/drivers/media/rc/rc-main.c
> > @@ -1017,7 +1017,7 @@ static void ir_close(struct input_dev *idev)
> > }
> >
> > /* class for /sys/class/rc */
> > -static char *rc_devnode(struct device *dev, umode_t *mode)
> > +static char *rc_devnode(const struct device *dev, umode_t *mode)
> > {
> > return kasprintf(GFP_KERNEL, "rc/%s", dev_name(dev));
> > }
> > diff --git a/drivers/misc/genwqe/card_base.c b/drivers/misc/genwqe/card_base.c
> > index 693981891870..0f00687f72d4 100644
> > --- a/drivers/misc/genwqe/card_base.c
> > +++ b/drivers/misc/genwqe/card_base.c
> > @@ -1349,7 +1349,7 @@ static struct pci_driver genwqe_driver = {
> > * Default mode should be rw for everybody. Do not change default
> > * device name.
> > */
> > -static char *genwqe_devnode(struct device *dev, umode_t *mode)
> > +static char *genwqe_devnode(const struct device *dev, umode_t *mode)
> > {
> > if (mode)
> > *mode = 0666;
> > diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
> > index de06c3c2ff70..aad8171f6c21 100644
> > --- a/drivers/tty/tty_io.c
> > +++ b/drivers/tty/tty_io.c
> > @@ -3494,7 +3494,7 @@ void tty_default_fops(struct file_operations *fops)
> > *fops = tty_fops;
> > }
> >
> > -static char *tty_devnode(struct device *dev, umode_t *mode)
> > +static char *tty_devnode(const struct device *dev, umode_t *mode)
> > {
> > if (!mode)
> > return NULL;
> > diff --git a/drivers/usb/core/file.c b/drivers/usb/core/file.c
> > index 558890ada0e5..da7d88e069e6 100644
> > --- a/drivers/usb/core/file.c
> > +++ b/drivers/usb/core/file.c
> > @@ -62,7 +62,7 @@ static struct usb_class {
> > struct class *class;
> > } *usb_class;
> >
> > -static char *usb_devnode(struct device *dev, umode_t *mode)
> > +static char *usb_devnode(const struct device *dev, umode_t *mode)
> > {
> > struct usb_class_driver *drv;
> >
> > diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
> > index 35dceee3ed56..0dd3c1f291da 100644
> > --- a/drivers/vdpa/vdpa_user/vduse_dev.c
> > +++ b/drivers/vdpa/vdpa_user/vduse_dev.c
> > @@ -1656,7 +1656,7 @@ static const struct file_operations vduse_ctrl_fops = {
> > .llseek = noop_llseek,
> > };
> >
> > -static char *vduse_devnode(struct device *dev, umode_t *mode)
> > +static char *vduse_devnode(const struct device *dev, umode_t *mode)
> > {
> > return kasprintf(GFP_KERNEL, "vduse/%s", dev_name(dev));
> > }
> > diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> > index 6e8804fe0095..5bf4b3454918 100644
> > --- a/drivers/vfio/vfio_main.c
> > +++ b/drivers/vfio/vfio_main.c
> > @@ -1812,7 +1812,7 @@ EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
> > /*
> > * Module/class support
> > */
> > -static char *vfio_devnode(struct device *dev, umode_t *mode)
> > +static char *vfio_devnode(const struct device *dev, umode_t *mode)
> > {
> > return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev));
> > }
> > diff --git a/fs/pstore/pmsg.c b/fs/pstore/pmsg.c
> > index d8542ec2f38c..b31c9c72d90b 100644
> > --- a/fs/pstore/pmsg.c
> > +++ b/fs/pstore/pmsg.c
> > @@ -46,7 +46,7 @@ static int pmsg_major;
> > #undef pr_fmt
> > #define pr_fmt(fmt) PMSG_NAME ": " fmt
> >
> > -static char *pmsg_devnode(struct device *dev, umode_t *mode)
> > +static char *pmsg_devnode(const struct device *dev, umode_t *mode)
> > {
> > if (mode)
> > *mode = 0220;
> > diff --git a/include/linux/device/class.h b/include/linux/device/class.h
> > index 94b1107258e5..42cc3fb44a84 100644
> > --- a/include/linux/device/class.h
> > +++ b/include/linux/device/class.h
> > @@ -60,7 +60,7 @@ struct class {
> > struct kobject *dev_kobj;
> >
> > int (*dev_uevent)(const struct device *dev, struct kobj_uevent_env *env);
> > - char *(*devnode)(struct device *dev, umode_t *mode);
> > + char *(*devnode)(const struct device *dev, umode_t *mode);
> >
> > void (*class_release)(struct class *class);
> > void (*dev_release)(struct device *dev);
> > diff --git a/sound/sound_core.c b/sound/sound_core.c
> > index 3332fe321737..3e7dd6fcb7cf 100644
> > --- a/sound/sound_core.c
> > +++ b/sound/sound_core.c
> > @@ -30,7 +30,7 @@ MODULE_DESCRIPTION("Core sound module");
> > MODULE_AUTHOR("Alan Cox");
> > MODULE_LICENSE("GPL");
> >
> > -static char *sound_devnode(struct device *dev, umode_t *mode)
> > +static char *sound_devnode(const struct device *dev, umode_t *mode)
> > {
> > if (MAJOR(dev->devt) == SOUND_MAJOR)
> > return NULL;

--
Thanks and regards,

Sumit Semwal (he / him)
Tech Lead - LCG, Vertical Technologies
Linaro.org │ Open source software for ARM SoCs