[PATCH] fs: move FMODE_UNSIGNED_OFFSET to fop_flags

[PATCH] fs: move FMODE_UNSIGNED_OFFSET to fop_flags

[Christian Brauner]

This is another flag that is statically set and doesn't need to use up
an FMODE_* bit. Move it to ->fop_flags and free up another FMODE_* bit.

(1) mem_open() used from proc_mem_operations
(2) adi_open() used from adi_fops
(3) drm_open_helper():
    (3.1) accel_open() used from DRM_ACCEL_FOPS
    (3.2) drm_open() used from
    (3.2.1) amdgpu_driver_kms_fops
    (3.2.2) psb_gem_fops
    (3.2.3) i915_driver_fops
    (3.2.4) nouveau_driver_fops
    (3.2.5) panthor_drm_driver_fops
    (3.2.6) radeon_driver_kms_fops
    (3.2.7) tegra_drm_fops
    (3.2.8) vmwgfx_driver_fops
    (3.2.9) xe_driver_fops
    (3.2.10) DRM_GEM_FOPS
    (3.2.11) DEFINE_DRM_GEM_DMA_FOPS
(4) struct memdev sets fmode flags based on type of device opened. For
    devices using struct mem_fops unsigned offset is used.

Mark all these file operations as FOP_UNSIGNED_OFFSET and add asserts
into the open helper to ensure that the flag is always set.

Signed-off-by: Christian Brauner <brauner@kernel.org>
---
---
 drivers/char/adi.c                      |  8 +-------
 drivers/char/mem.c                      |  3 ++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c |  1 +
 drivers/gpu/drm/drm_file.c              |  3 ++-
 drivers/gpu/drm/gma500/psb_drv.c        |  1 +
 drivers/gpu/drm/i915/i915_driver.c      |  1 +
 drivers/gpu/drm/nouveau/nouveau_drm.c   |  1 +
 drivers/gpu/drm/radeon/radeon_drv.c     |  1 +
 drivers/gpu/drm/tegra/drm.c             |  1 +
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.c     |  1 +
 drivers/gpu/drm/xe/xe_device.c          |  1 +
 fs/proc/base.c                          | 10 ++++------
 fs/read_write.c                         |  2 +-
 include/drm/drm_accel.h                 |  3 ++-
 include/drm/drm_gem.h                   |  3 ++-
 include/drm/drm_gem_dma_helper.h        |  1 +
 include/linux/fs.h                      |  5 +++--
 mm/mmap.c                               |  2 +-
 18 files changed, 27 insertions(+), 21 deletions(-)

diff --git a/drivers/char/adi.c b/drivers/char/adi.c
index 751d7cc0da1b..1c76c8758f0f 100644
--- a/drivers/char/adi.c
+++ b/drivers/char/adi.c
@@ -14,12 +14,6 @@
 
 #define MAX_BUF_SZ	PAGE_SIZE
 
-static int adi_open(struct inode *inode, struct file *file)
-{
-	file->f_mode |= FMODE_UNSIGNED_OFFSET;
-	return 0;
-}
-
 static int read_mcd_tag(unsigned long addr)
 {
 	long err;
@@ -206,9 +200,9 @@ static loff_t adi_llseek(struct file *file, loff_t offset, int whence)
 static const struct file_operations adi_fops = {
 	.owner		= THIS_MODULE,
 	.llseek		= adi_llseek,
-	.open		= adi_open,
 	.read		= adi_read,
 	.write		= adi_write,
+	.fop_flags	= FOP_UNSIGNED_OFFSET,
 };
 
 static struct miscdevice adi_miscdev = {
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 7c359cc406d5..169eed162a7f 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -643,6 +643,7 @@ static const struct file_operations __maybe_unused mem_fops = {
 	.get_unmapped_area = get_unmapped_area_mem,
 	.mmap_capabilities = memory_mmap_capabilities,
 #endif
+	.fop_flags	= FOP_UNSIGNED_OFFSET,
 };
 
 static const struct file_operations null_fops = {
@@ -693,7 +694,7 @@ static const struct memdev {
 	umode_t mode;
 } devlist[] = {
 #ifdef CONFIG_DEVMEM
-	[DEVMEM_MINOR] = { "mem", &mem_fops, FMODE_UNSIGNED_OFFSET, 0 },
+	[DEVMEM_MINOR] = { "mem", &mem_fops, 0, 0 },
 #endif
 	[3] = { "null", &null_fops, FMODE_NOWAIT, 0666 },
 #ifdef CONFIG_DEVPORT
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index 094498a0964b..d7ef8cbecf6c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -2908,6 +2908,7 @@ static const struct file_operations amdgpu_driver_kms_fops = {
 #ifdef CONFIG_PROC_FS
 	.show_fdinfo = drm_show_fdinfo,
 #endif
+	.fop_flags = FOP_UNSIGNED_OFFSET,
 };
 
 int amdgpu_file_to_fpriv(struct file *filp, struct amdgpu_fpriv **fpriv)
diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
index 714e42b05108..f8de3cba1a08 100644
--- a/drivers/gpu/drm/drm_file.c
+++ b/drivers/gpu/drm/drm_file.c
@@ -318,6 +318,8 @@ int drm_open_helper(struct file *filp, struct drm_minor *minor)
 	if (dev->switch_power_state != DRM_SWITCH_POWER_ON &&
 	    dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
 		return -EINVAL;
+	if (WARN_ON_ONCE(!(filp->f_op->fop_flags & FOP_UNSIGNED_OFFSET)))
+		return -EINVAL;
 
 	drm_dbg_core(dev, "comm=\"%s\", pid=%d, minor=%d\n",
 		     current->comm, task_pid_nr(current), minor->index);
@@ -335,7 +337,6 @@ int drm_open_helper(struct file *filp, struct drm_minor *minor)
 	}
 
 	filp->private_data = priv;
-	filp->f_mode |= FMODE_UNSIGNED_OFFSET;
 	priv->filp = filp;
 
 	mutex_lock(&dev->filelist_mutex);
diff --git a/drivers/gpu/drm/gma500/psb_drv.c b/drivers/gpu/drm/gma500/psb_drv.c
index 8b64f61ffaf9..d67c2b3ad901 100644
--- a/drivers/gpu/drm/gma500/psb_drv.c
+++ b/drivers/gpu/drm/gma500/psb_drv.c
@@ -498,6 +498,7 @@ static const struct file_operations psb_gem_fops = {
 	.mmap = drm_gem_mmap,
 	.poll = drm_poll,
 	.read = drm_read,
+	.fop_flags = FOP_UNSIGNED_OFFSET,
 };
 
 static const struct drm_driver driver = {
diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
index fb8e9c2fcea5..cf276299bccb 100644
--- a/drivers/gpu/drm/i915/i915_driver.c
+++ b/drivers/gpu/drm/i915/i915_driver.c
@@ -1671,6 +1671,7 @@ static const struct file_operations i915_driver_fops = {
 #ifdef CONFIG_PROC_FS
 	.show_fdinfo = drm_show_fdinfo,
 #endif
+	.fop_flags = FOP_UNSIGNED_OFFSET,
 };
 
 static int
diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
index a58c31089613..e243b42f8582 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
@@ -1274,6 +1274,7 @@ nouveau_driver_fops = {
 	.compat_ioctl = nouveau_compat_ioctl,
 #endif
 	.llseek = noop_llseek,
+	.fop_flags = FOP_UNSIGNED_OFFSET,
 };
 
 static struct drm_driver
diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c
index 7bf08164140e..ac49779ed03d 100644
--- a/drivers/gpu/drm/radeon/radeon_drv.c
+++ b/drivers/gpu/drm/radeon/radeon_drv.c
@@ -520,6 +520,7 @@ static const struct file_operations radeon_driver_kms_fops = {
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = radeon_kms_compat_ioctl,
 #endif
+	.fop_flags = FOP_UNSIGNED_OFFSET,
 };
 
 static const struct drm_ioctl_desc radeon_ioctls_kms[] = {
diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index 03d1c76aec2d..108c26a33edb 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -801,6 +801,7 @@ static const struct file_operations tegra_drm_fops = {
 	.read = drm_read,
 	.compat_ioctl = drm_compat_ioctl,
 	.llseek = noop_llseek,
+	.fop_flags = FOP_UNSIGNED_OFFSET,
 };
 
 static int tegra_drm_context_cleanup(int id, void *p, void *data)
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index 50ad3105c16e..2825dd3149ed 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -1609,6 +1609,7 @@ static const struct file_operations vmwgfx_driver_fops = {
 	.compat_ioctl = vmw_compat_ioctl,
 #endif
 	.llseek = noop_llseek,
+	.fop_flags = FOP_UNSIGNED_OFFSET,
 };
 
 static const struct drm_driver driver = {
diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
index 76109415eba6..ea7e3ff6feba 100644
--- a/drivers/gpu/drm/xe/xe_device.c
+++ b/drivers/gpu/drm/xe/xe_device.c
@@ -197,6 +197,7 @@ static const struct file_operations xe_driver_fops = {
 #ifdef CONFIG_PROC_FS
 	.show_fdinfo = drm_show_fdinfo,
 #endif
+	.fop_flags = FOP_UNSIGNED_OFFSET,
 };
 
 static struct drm_driver driver = {
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 72a1acd03675..1409d1003101 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -827,12 +827,9 @@ static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
 
 static int mem_open(struct inode *inode, struct file *file)
 {
-	int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
-
-	/* OK to pass negative loff_t, we can catch out-of-range */
-	file->f_mode |= FMODE_UNSIGNED_OFFSET;
-
-	return ret;
+	if (WARN_ON_ONCE(!(file->f_op->fop_flags & FOP_UNSIGNED_OFFSET)))
+		return -EINVAL;
+	return __mem_open(inode, file, PTRACE_MODE_ATTACH);
 }
 
 static ssize_t mem_rw(struct file *file, char __user *buf,
@@ -932,6 +929,7 @@ static const struct file_operations proc_mem_operations = {
 	.write		= mem_write,
 	.open		= mem_open,
 	.release	= mem_release,
+	.fop_flags	= FOP_UNSIGNED_OFFSET,
 };
 
 static int environ_open(struct inode *inode, struct file *file)
diff --git a/fs/read_write.c b/fs/read_write.c
index 90e283b31ca1..89d4af0e3b93 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -36,7 +36,7 @@ EXPORT_SYMBOL(generic_ro_fops);
 
 static inline bool unsigned_offsets(struct file *file)
 {
-	return file->f_mode & FMODE_UNSIGNED_OFFSET;
+	return file->f_op->fop_flags & FOP_UNSIGNED_OFFSET;
 }
 
 /**
diff --git a/include/drm/drm_accel.h b/include/drm/drm_accel.h
index f4d3784b1dce..41c78b7d712c 100644
--- a/include/drm/drm_accel.h
+++ b/include/drm/drm_accel.h
@@ -28,7 +28,8 @@
 	.poll		= drm_poll,\
 	.read		= drm_read,\
 	.llseek		= noop_llseek, \
-	.mmap		= drm_gem_mmap
+	.mmap		= drm_gem_mmap, \
+	.fop_flags	= FOP_UNSIGNED_OFFSET
 
 /**
  * DEFINE_DRM_ACCEL_FOPS() - macro to generate file operations for accelerators drivers
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index bae4865b2101..d8b86df2ec0d 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -447,7 +447,8 @@ struct drm_gem_object {
 	.poll		= drm_poll,\
 	.read		= drm_read,\
 	.llseek		= noop_llseek,\
-	.mmap		= drm_gem_mmap
+	.mmap		= drm_gem_mmap, \
+	.fop_flags	= FOP_UNSIGNED_OFFSET
 
 /**
  * DEFINE_DRM_GEM_FOPS() - macro to generate file operations for GEM drivers
diff --git a/include/drm/drm_gem_dma_helper.h b/include/drm/drm_gem_dma_helper.h
index a827bde494f6..f2678e7ecb98 100644
--- a/include/drm/drm_gem_dma_helper.h
+++ b/include/drm/drm_gem_dma_helper.h
@@ -267,6 +267,7 @@ unsigned long drm_gem_dma_get_unmapped_area(struct file *filp,
 		.read		= drm_read,\
 		.llseek		= noop_llseek,\
 		.mmap		= drm_gem_mmap,\
+		.fop_flags = FOP_UNSIGNED_OFFSET, \
 		DRM_GEM_DMA_UNMAPPED_AREA_FOPS \
 	}
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index fd34b5755c0b..40ebfa09112c 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -146,8 +146,7 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
 /* Expect random access pattern */
 #define FMODE_RANDOM		((__force fmode_t)(1 << 12))
 
-/* File is huge (eg. /dev/mem): treat loff_t as unsigned */
-#define FMODE_UNSIGNED_OFFSET	((__force fmode_t)(1 << 13))
+/* FMODE_* bit 13 */
 
 /* File is opened with O_PATH; almost nothing can be done with it */
 #define FMODE_PATH		((__force fmode_t)(1 << 14))
@@ -2073,6 +2072,8 @@ struct file_operations {
 #define FOP_DIO_PARALLEL_WRITE	((__force fop_flags_t)(1 << 3))
 /* Contains huge pages */
 #define FOP_HUGE_PAGES		((__force fop_flags_t)(1 << 4))
+/* Treat loff_t as unsigned (e.g., /dev/mem) */
+#define FOP_UNSIGNED_OFFSET	((__force fop_flags_t)(1 << 5))
 
 /* Wrap a directory iterator that needs exclusive inode access */
 int wrap_directory_iterator(struct file *, struct dir_context *,
diff --git a/mm/mmap.c b/mm/mmap.c
index d0dfc85b209b..6ddb278a5ee8 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1229,7 +1229,7 @@ static inline u64 file_mmap_size_max(struct file *file, struct inode *inode)
 		return MAX_LFS_FILESIZE;
 
 	/* Special "we do even unsigned file positions" case */
-	if (file->f_mode & FMODE_UNSIGNED_OFFSET)
+	if (file->f_op->fop_flags & FOP_UNSIGNED_OFFSET)
 		return 0;
 
 	/* Yes, random drivers might want more. But I'm tired of buggy drivers */

---
base-commit: 8400291e289ee6b2bf9779ff1c83a291501f017b
change-id: 20240809-work-fop_unsigned-5f6f7734cb7b

Re: [PATCH] fs: move FMODE_UNSIGNED_OFFSET to fop_flags

[Jeff Layton]

On Fri, 2024-08-09 at 12:38 +0200, Christian Brauner wrote:
> This is another flag that is statically set and doesn't need to use up
> an FMODE_* bit. Move it to ->fop_flags and free up another FMODE_* bit.
> 
> (1) mem_open() used from proc_mem_operations
> (2) adi_open() used from adi_fops
> (3) drm_open_helper():
>     (3.1) accel_open() used from DRM_ACCEL_FOPS
>     (3.2) drm_open() used from
>     (3.2.1) amdgpu_driver_kms_fops
>     (3.2.2) psb_gem_fops
>     (3.2.3) i915_driver_fops
>     (3.2.4) nouveau_driver_fops
>     (3.2.5) panthor_drm_driver_fops
>     (3.2.6) radeon_driver_kms_fops
>     (3.2.7) tegra_drm_fops
>     (3.2.8) vmwgfx_driver_fops
>     (3.2.9) xe_driver_fops
>     (3.2.10) DRM_GEM_FOPS
>     (3.2.11) DEFINE_DRM_GEM_DMA_FOPS
> (4) struct memdev sets fmode flags based on type of device opened. For
>     devices using struct mem_fops unsigned offset is used.
> 
> Mark all these file operations as FOP_UNSIGNED_OFFSET and add asserts
> into the open helper to ensure that the flag is always set.
> 
> Signed-off-by: Christian Brauner <brauner@kernel.org>
> ---
> ---
>  drivers/char/adi.c                      |  8 +-------
>  drivers/char/mem.c                      |  3 ++-
>  drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c |  1 +
>  drivers/gpu/drm/drm_file.c              |  3 ++-
>  drivers/gpu/drm/gma500/psb_drv.c        |  1 +
>  drivers/gpu/drm/i915/i915_driver.c      |  1 +
>  drivers/gpu/drm/nouveau/nouveau_drm.c   |  1 +
>  drivers/gpu/drm/radeon/radeon_drv.c     |  1 +
>  drivers/gpu/drm/tegra/drm.c             |  1 +
>  drivers/gpu/drm/vmwgfx/vmwgfx_drv.c     |  1 +
>  drivers/gpu/drm/xe/xe_device.c          |  1 +
>  fs/proc/base.c                          | 10 ++++------
>  fs/read_write.c                         |  2 +-
>  include/drm/drm_accel.h                 |  3 ++-
>  include/drm/drm_gem.h                   |  3 ++-
>  include/drm/drm_gem_dma_helper.h        |  1 +
>  include/linux/fs.h                      |  5 +++--
>  mm/mmap.c                               |  2 +-
>  18 files changed, 27 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/char/adi.c b/drivers/char/adi.c
> index 751d7cc0da1b..1c76c8758f0f 100644
> --- a/drivers/char/adi.c
> +++ b/drivers/char/adi.c
> @@ -14,12 +14,6 @@
>  
>  #define MAX_BUF_SZ	PAGE_SIZE
>  
> -static int adi_open(struct inode *inode, struct file *file)
> -{
> -	file->f_mode |= FMODE_UNSIGNED_OFFSET;
> -	return 0;
> -}
> -
>  static int read_mcd_tag(unsigned long addr)
>  {
>  	long err;
> @@ -206,9 +200,9 @@ static loff_t adi_llseek(struct file *file, loff_t offset, int whence)
>  static const struct file_operations adi_fops = {
>  	.owner		= THIS_MODULE,
>  	.llseek		= adi_llseek,
> -	.open		= adi_open,
>  	.read		= adi_read,
>  	.write		= adi_write,
> +	.fop_flags	= FOP_UNSIGNED_OFFSET,
>  };
>  
>  static struct miscdevice adi_miscdev = {
> diff --git a/drivers/char/mem.c b/drivers/char/mem.c
> index 7c359cc406d5..169eed162a7f 100644
> --- a/drivers/char/mem.c
> +++ b/drivers/char/mem.c
> @@ -643,6 +643,7 @@ static const struct file_operations __maybe_unused mem_fops = {
>  	.get_unmapped_area = get_unmapped_area_mem,
>  	.mmap_capabilities = memory_mmap_capabilities,
>  #endif
> +	.fop_flags	= FOP_UNSIGNED_OFFSET,
>  };
>  
>  static const struct file_operations null_fops = {
> @@ -693,7 +694,7 @@ static const struct memdev {
>  	umode_t mode;
>  } devlist[] = {
>  #ifdef CONFIG_DEVMEM
> -	[DEVMEM_MINOR] = { "mem", &mem_fops, FMODE_UNSIGNED_OFFSET, 0 },
> +	[DEVMEM_MINOR] = { "mem", &mem_fops, 0, 0 },
>  #endif
>  	[3] = { "null", &null_fops, FMODE_NOWAIT, 0666 },
>  #ifdef CONFIG_DEVPORT
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> index 094498a0964b..d7ef8cbecf6c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> @@ -2908,6 +2908,7 @@ static const struct file_operations amdgpu_driver_kms_fops = {
>  #ifdef CONFIG_PROC_FS
>  	.show_fdinfo = drm_show_fdinfo,
>  #endif
> +	.fop_flags = FOP_UNSIGNED_OFFSET,
>  };
>  
>  int amdgpu_file_to_fpriv(struct file *filp, struct amdgpu_fpriv **fpriv)
> diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
> index 714e42b05108..f8de3cba1a08 100644
> --- a/drivers/gpu/drm/drm_file.c
> +++ b/drivers/gpu/drm/drm_file.c
> @@ -318,6 +318,8 @@ int drm_open_helper(struct file *filp, struct drm_minor *minor)
>  	if (dev->switch_power_state != DRM_SWITCH_POWER_ON &&
>  	    dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
>  		return -EINVAL;
> +	if (WARN_ON_ONCE(!(filp->f_op->fop_flags & FOP_UNSIGNED_OFFSET)))
> +		return -EINVAL;
>  
>  	drm_dbg_core(dev, "comm=\"%s\", pid=%d, minor=%d\n",
>  		     current->comm, task_pid_nr(current), minor->index);
> @@ -335,7 +337,6 @@ int drm_open_helper(struct file *filp, struct drm_minor *minor)
>  	}
>  
>  	filp->private_data = priv;
> -	filp->f_mode |= FMODE_UNSIGNED_OFFSET;
>  	priv->filp = filp;
>  
>  	mutex_lock(&dev->filelist_mutex);
> diff --git a/drivers/gpu/drm/gma500/psb_drv.c b/drivers/gpu/drm/gma500/psb_drv.c
> index 8b64f61ffaf9..d67c2b3ad901 100644
> --- a/drivers/gpu/drm/gma500/psb_drv.c
> +++ b/drivers/gpu/drm/gma500/psb_drv.c
> @@ -498,6 +498,7 @@ static const struct file_operations psb_gem_fops = {
>  	.mmap = drm_gem_mmap,
>  	.poll = drm_poll,
>  	.read = drm_read,
> +	.fop_flags = FOP_UNSIGNED_OFFSET,
>  };
>  
>  static const struct drm_driver driver = {
> diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
> index fb8e9c2fcea5..cf276299bccb 100644
> --- a/drivers/gpu/drm/i915/i915_driver.c
> +++ b/drivers/gpu/drm/i915/i915_driver.c
> @@ -1671,6 +1671,7 @@ static const struct file_operations i915_driver_fops = {
>  #ifdef CONFIG_PROC_FS
>  	.show_fdinfo = drm_show_fdinfo,
>  #endif
> +	.fop_flags = FOP_UNSIGNED_OFFSET,
>  };
>  
>  static int
> diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
> index a58c31089613..e243b42f8582 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_drm.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
> @@ -1274,6 +1274,7 @@ nouveau_driver_fops = {
>  	.compat_ioctl = nouveau_compat_ioctl,
>  #endif
>  	.llseek = noop_llseek,
> +	.fop_flags = FOP_UNSIGNED_OFFSET,
>  };
>  
>  static struct drm_driver
> diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c
> index 7bf08164140e..ac49779ed03d 100644
> --- a/drivers/gpu/drm/radeon/radeon_drv.c
> +++ b/drivers/gpu/drm/radeon/radeon_drv.c
> @@ -520,6 +520,7 @@ static const struct file_operations radeon_driver_kms_fops = {
>  #ifdef CONFIG_COMPAT
>  	.compat_ioctl = radeon_kms_compat_ioctl,
>  #endif
> +	.fop_flags = FOP_UNSIGNED_OFFSET,
>  };
>  
>  static const struct drm_ioctl_desc radeon_ioctls_kms[] = {
> diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
> index 03d1c76aec2d..108c26a33edb 100644
> --- a/drivers/gpu/drm/tegra/drm.c
> +++ b/drivers/gpu/drm/tegra/drm.c
> @@ -801,6 +801,7 @@ static const struct file_operations tegra_drm_fops = {
>  	.read = drm_read,
>  	.compat_ioctl = drm_compat_ioctl,
>  	.llseek = noop_llseek,
> +	.fop_flags = FOP_UNSIGNED_OFFSET,
>  };
>  
>  static int tegra_drm_context_cleanup(int id, void *p, void *data)
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> index 50ad3105c16e..2825dd3149ed 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> @@ -1609,6 +1609,7 @@ static const struct file_operations vmwgfx_driver_fops = {
>  	.compat_ioctl = vmw_compat_ioctl,
>  #endif
>  	.llseek = noop_llseek,
> +	.fop_flags = FOP_UNSIGNED_OFFSET,
>  };
>  
>  static const struct drm_driver driver = {
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index 76109415eba6..ea7e3ff6feba 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -197,6 +197,7 @@ static const struct file_operations xe_driver_fops = {
>  #ifdef CONFIG_PROC_FS
>  	.show_fdinfo = drm_show_fdinfo,
>  #endif
> +	.fop_flags = FOP_UNSIGNED_OFFSET,
>  };
>  
>  static struct drm_driver driver = {
> diff --git a/fs/proc/base.c b/fs/proc/base.c
> index 72a1acd03675..1409d1003101 100644
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -827,12 +827,9 @@ static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
>  
>  static int mem_open(struct inode *inode, struct file *file)
>  {
> -	int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
> -
> -	/* OK to pass negative loff_t, we can catch out-of-range */
> -	file->f_mode |= FMODE_UNSIGNED_OFFSET;
> -
> -	return ret;
> +	if (WARN_ON_ONCE(!(file->f_op->fop_flags & FOP_UNSIGNED_OFFSET)))
> +		return -EINVAL;
> +	return __mem_open(inode, file, PTRACE_MODE_ATTACH);
>  }
>  
>  static ssize_t mem_rw(struct file *file, char __user *buf,
> @@ -932,6 +929,7 @@ static const struct file_operations proc_mem_operations = {
>  	.write		= mem_write,
>  	.open		= mem_open,
>  	.release	= mem_release,
> +	.fop_flags	= FOP_UNSIGNED_OFFSET,
>  };
>  
>  static int environ_open(struct inode *inode, struct file *file)
> diff --git a/fs/read_write.c b/fs/read_write.c
> index 90e283b31ca1..89d4af0e3b93 100644
> --- a/fs/read_write.c
> +++ b/fs/read_write.c
> @@ -36,7 +36,7 @@ EXPORT_SYMBOL(generic_ro_fops);
>  
>  static inline bool unsigned_offsets(struct file *file)
>  {
> -	return file->f_mode & FMODE_UNSIGNED_OFFSET;
> +	return file->f_op->fop_flags & FOP_UNSIGNED_OFFSET;
>  }
>  
>  /**
> diff --git a/include/drm/drm_accel.h b/include/drm/drm_accel.h
> index f4d3784b1dce..41c78b7d712c 100644
> --- a/include/drm/drm_accel.h
> +++ b/include/drm/drm_accel.h
> @@ -28,7 +28,8 @@
>  	.poll		= drm_poll,\
>  	.read		= drm_read,\
>  	.llseek		= noop_llseek, \
> -	.mmap		= drm_gem_mmap
> +	.mmap		= drm_gem_mmap, \
> +	.fop_flags	= FOP_UNSIGNED_OFFSET
>  
>  /**
>   * DEFINE_DRM_ACCEL_FOPS() - macro to generate file operations for accelerators drivers
> diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
> index bae4865b2101..d8b86df2ec0d 100644
> --- a/include/drm/drm_gem.h
> +++ b/include/drm/drm_gem.h
> @@ -447,7 +447,8 @@ struct drm_gem_object {
>  	.poll		= drm_poll,\
>  	.read		= drm_read,\
>  	.llseek		= noop_llseek,\
> -	.mmap		= drm_gem_mmap
> +	.mmap		= drm_gem_mmap, \
> +	.fop_flags	= FOP_UNSIGNED_OFFSET
>  
>  /**
>   * DEFINE_DRM_GEM_FOPS() - macro to generate file operations for GEM drivers
> diff --git a/include/drm/drm_gem_dma_helper.h b/include/drm/drm_gem_dma_helper.h
> index a827bde494f6..f2678e7ecb98 100644
> --- a/include/drm/drm_gem_dma_helper.h
> +++ b/include/drm/drm_gem_dma_helper.h
> @@ -267,6 +267,7 @@ unsigned long drm_gem_dma_get_unmapped_area(struct file *filp,
>  		.read		= drm_read,\
>  		.llseek		= noop_llseek,\
>  		.mmap		= drm_gem_mmap,\
> +		.fop_flags = FOP_UNSIGNED_OFFSET, \
>  		DRM_GEM_DMA_UNMAPPED_AREA_FOPS \
>  	}
>  
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index fd34b5755c0b..40ebfa09112c 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -146,8 +146,7 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
>  /* Expect random access pattern */
>  #define FMODE_RANDOM		((__force fmode_t)(1 << 12))
>  
> -/* File is huge (eg. /dev/mem): treat loff_t as unsigned */
> -#define FMODE_UNSIGNED_OFFSET	((__force fmode_t)(1 << 13))
> +/* FMODE_* bit 13 */
>  
>  /* File is opened with O_PATH; almost nothing can be done with it */
>  #define FMODE_PATH		((__force fmode_t)(1 << 14))
> @@ -2073,6 +2072,8 @@ struct file_operations {
>  #define FOP_DIO_PARALLEL_WRITE	((__force fop_flags_t)(1 << 3))
>  /* Contains huge pages */
>  #define FOP_HUGE_PAGES		((__force fop_flags_t)(1 << 4))
> +/* Treat loff_t as unsigned (e.g., /dev/mem) */
> +#define FOP_UNSIGNED_OFFSET	((__force fop_flags_t)(1 << 5))
>  
>  /* Wrap a directory iterator that needs exclusive inode access */
>  int wrap_directory_iterator(struct file *, struct dir_context *,
> diff --git a/mm/mmap.c b/mm/mmap.c
> index d0dfc85b209b..6ddb278a5ee8 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -1229,7 +1229,7 @@ static inline u64 file_mmap_size_max(struct file *file, struct inode *inode)
>  		return MAX_LFS_FILESIZE;
>  
>  	/* Special "we do even unsigned file positions" case */
> -	if (file->f_mode & FMODE_UNSIGNED_OFFSET)
> +	if (file->f_op->fop_flags & FOP_UNSIGNED_OFFSET)
>  		return 0;
>  
>  	/* Yes, random drivers might want more. But I'm tired of buggy drivers */
> 
> ---
> base-commit: 8400291e289ee6b2bf9779ff1c83a291501f017b
> change-id: 20240809-work-fop_unsigned-5f6f7734cb7b
> 

Nice.

Reviewed-by: Jeff Layton <jlayton@kernel.org>

Re: [PATCH] fs: move FMODE_UNSIGNED_OFFSET to fop_flags

[Jan Kara]

On Fri 09-08-24 12:38:56, Christian Brauner wrote:
> This is another flag that is statically set and doesn't need to use up
> an FMODE_* bit. Move it to ->fop_flags and free up another FMODE_* bit.
> 
> (1) mem_open() used from proc_mem_operations
> (2) adi_open() used from adi_fops
> (3) drm_open_helper():
>     (3.1) accel_open() used from DRM_ACCEL_FOPS
>     (3.2) drm_open() used from
>     (3.2.1) amdgpu_driver_kms_fops
>     (3.2.2) psb_gem_fops
>     (3.2.3) i915_driver_fops
>     (3.2.4) nouveau_driver_fops
>     (3.2.5) panthor_drm_driver_fops
>     (3.2.6) radeon_driver_kms_fops
>     (3.2.7) tegra_drm_fops
>     (3.2.8) vmwgfx_driver_fops
>     (3.2.9) xe_driver_fops
>     (3.2.10) DRM_GEM_FOPS
>     (3.2.11) DEFINE_DRM_GEM_DMA_FOPS
> (4) struct memdev sets fmode flags based on type of device opened. For
>     devices using struct mem_fops unsigned offset is used.
> 
> Mark all these file operations as FOP_UNSIGNED_OFFSET and add asserts
> into the open helper to ensure that the flag is always set.
> 
> Signed-off-by: Christian Brauner <brauner@kernel.org>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
> ---
>  drivers/char/adi.c                      |  8 +-------
>  drivers/char/mem.c                      |  3 ++-
>  drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c |  1 +
>  drivers/gpu/drm/drm_file.c              |  3 ++-
>  drivers/gpu/drm/gma500/psb_drv.c        |  1 +
>  drivers/gpu/drm/i915/i915_driver.c      |  1 +
>  drivers/gpu/drm/nouveau/nouveau_drm.c   |  1 +
>  drivers/gpu/drm/radeon/radeon_drv.c     |  1 +
>  drivers/gpu/drm/tegra/drm.c             |  1 +
>  drivers/gpu/drm/vmwgfx/vmwgfx_drv.c     |  1 +
>  drivers/gpu/drm/xe/xe_device.c          |  1 +
>  fs/proc/base.c                          | 10 ++++------
>  fs/read_write.c                         |  2 +-
>  include/drm/drm_accel.h                 |  3 ++-
>  include/drm/drm_gem.h                   |  3 ++-
>  include/drm/drm_gem_dma_helper.h        |  1 +
>  include/linux/fs.h                      |  5 +++--
>  mm/mmap.c                               |  2 +-
>  18 files changed, 27 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/char/adi.c b/drivers/char/adi.c
> index 751d7cc0da1b..1c76c8758f0f 100644
> --- a/drivers/char/adi.c
> +++ b/drivers/char/adi.c
> @@ -14,12 +14,6 @@
>  
>  #define MAX_BUF_SZ	PAGE_SIZE
>  
> -static int adi_open(struct inode *inode, struct file *file)
> -{
> -	file->f_mode |= FMODE_UNSIGNED_OFFSET;
> -	return 0;
> -}
> -
>  static int read_mcd_tag(unsigned long addr)
>  {
>  	long err;
> @@ -206,9 +200,9 @@ static loff_t adi_llseek(struct file *file, loff_t offset, int whence)
>  static const struct file_operations adi_fops = {
>  	.owner		= THIS_MODULE,
>  	.llseek		= adi_llseek,
> -	.open		= adi_open,
>  	.read		= adi_read,
>  	.write		= adi_write,
> +	.fop_flags	= FOP_UNSIGNED_OFFSET,
>  };
>  
>  static struct miscdevice adi_miscdev = {
> diff --git a/drivers/char/mem.c b/drivers/char/mem.c
> index 7c359cc406d5..169eed162a7f 100644
> --- a/drivers/char/mem.c
> +++ b/drivers/char/mem.c
> @@ -643,6 +643,7 @@ static const struct file_operations __maybe_unused mem_fops = {
>  	.get_unmapped_area = get_unmapped_area_mem,
>  	.mmap_capabilities = memory_mmap_capabilities,
>  #endif
> +	.fop_flags	= FOP_UNSIGNED_OFFSET,
>  };
>  
>  static const struct file_operations null_fops = {
> @@ -693,7 +694,7 @@ static const struct memdev {
>  	umode_t mode;
>  } devlist[] = {
>  #ifdef CONFIG_DEVMEM
> -	[DEVMEM_MINOR] = { "mem", &mem_fops, FMODE_UNSIGNED_OFFSET, 0 },
> +	[DEVMEM_MINOR] = { "mem", &mem_fops, 0, 0 },
>  #endif
>  	[3] = { "null", &null_fops, FMODE_NOWAIT, 0666 },
>  #ifdef CONFIG_DEVPORT
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> index 094498a0964b..d7ef8cbecf6c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> @@ -2908,6 +2908,7 @@ static const struct file_operations amdgpu_driver_kms_fops = {
>  #ifdef CONFIG_PROC_FS
>  	.show_fdinfo = drm_show_fdinfo,
>  #endif
> +	.fop_flags = FOP_UNSIGNED_OFFSET,
>  };
>  
>  int amdgpu_file_to_fpriv(struct file *filp, struct amdgpu_fpriv **fpriv)
> diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
> index 714e42b05108..f8de3cba1a08 100644
> --- a/drivers/gpu/drm/drm_file.c
> +++ b/drivers/gpu/drm/drm_file.c
> @@ -318,6 +318,8 @@ int drm_open_helper(struct file *filp, struct drm_minor *minor)
>  	if (dev->switch_power_state != DRM_SWITCH_POWER_ON &&
>  	    dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
>  		return -EINVAL;
> +	if (WARN_ON_ONCE(!(filp->f_op->fop_flags & FOP_UNSIGNED_OFFSET)))
> +		return -EINVAL;
>  
>  	drm_dbg_core(dev, "comm=\"%s\", pid=%d, minor=%d\n",
>  		     current->comm, task_pid_nr(current), minor->index);
> @@ -335,7 +337,6 @@ int drm_open_helper(struct file *filp, struct drm_minor *minor)
>  	}
>  
>  	filp->private_data = priv;
> -	filp->f_mode |= FMODE_UNSIGNED_OFFSET;
>  	priv->filp = filp;
>  
>  	mutex_lock(&dev->filelist_mutex);
> diff --git a/drivers/gpu/drm/gma500/psb_drv.c b/drivers/gpu/drm/gma500/psb_drv.c
> index 8b64f61ffaf9..d67c2b3ad901 100644
> --- a/drivers/gpu/drm/gma500/psb_drv.c
> +++ b/drivers/gpu/drm/gma500/psb_drv.c
> @@ -498,6 +498,7 @@ static const struct file_operations psb_gem_fops = {
>  	.mmap = drm_gem_mmap,
>  	.poll = drm_poll,
>  	.read = drm_read,
> +	.fop_flags = FOP_UNSIGNED_OFFSET,
>  };
>  
>  static const struct drm_driver driver = {
> diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
> index fb8e9c2fcea5..cf276299bccb 100644
> --- a/drivers/gpu/drm/i915/i915_driver.c
> +++ b/drivers/gpu/drm/i915/i915_driver.c
> @@ -1671,6 +1671,7 @@ static const struct file_operations i915_driver_fops = {
>  #ifdef CONFIG_PROC_FS
>  	.show_fdinfo = drm_show_fdinfo,
>  #endif
> +	.fop_flags = FOP_UNSIGNED_OFFSET,
>  };
>  
>  static int
> diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
> index a58c31089613..e243b42f8582 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_drm.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
> @@ -1274,6 +1274,7 @@ nouveau_driver_fops = {
>  	.compat_ioctl = nouveau_compat_ioctl,
>  #endif
>  	.llseek = noop_llseek,
> +	.fop_flags = FOP_UNSIGNED_OFFSET,
>  };
>  
>  static struct drm_driver
> diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c
> index 7bf08164140e..ac49779ed03d 100644
> --- a/drivers/gpu/drm/radeon/radeon_drv.c
> +++ b/drivers/gpu/drm/radeon/radeon_drv.c
> @@ -520,6 +520,7 @@ static const struct file_operations radeon_driver_kms_fops = {
>  #ifdef CONFIG_COMPAT
>  	.compat_ioctl = radeon_kms_compat_ioctl,
>  #endif
> +	.fop_flags = FOP_UNSIGNED_OFFSET,
>  };
>  
>  static const struct drm_ioctl_desc radeon_ioctls_kms[] = {
> diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
> index 03d1c76aec2d..108c26a33edb 100644
> --- a/drivers/gpu/drm/tegra/drm.c
> +++ b/drivers/gpu/drm/tegra/drm.c
> @@ -801,6 +801,7 @@ static const struct file_operations tegra_drm_fops = {
>  	.read = drm_read,
>  	.compat_ioctl = drm_compat_ioctl,
>  	.llseek = noop_llseek,
> +	.fop_flags = FOP_UNSIGNED_OFFSET,
>  };
>  
>  static int tegra_drm_context_cleanup(int id, void *p, void *data)
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> index 50ad3105c16e..2825dd3149ed 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> @@ -1609,6 +1609,7 @@ static const struct file_operations vmwgfx_driver_fops = {
>  	.compat_ioctl = vmw_compat_ioctl,
>  #endif
>  	.llseek = noop_llseek,
> +	.fop_flags = FOP_UNSIGNED_OFFSET,
>  };
>  
>  static const struct drm_driver driver = {
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index 76109415eba6..ea7e3ff6feba 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -197,6 +197,7 @@ static const struct file_operations xe_driver_fops = {
>  #ifdef CONFIG_PROC_FS
>  	.show_fdinfo = drm_show_fdinfo,
>  #endif
> +	.fop_flags = FOP_UNSIGNED_OFFSET,
>  };
>  
>  static struct drm_driver driver = {
> diff --git a/fs/proc/base.c b/fs/proc/base.c
> index 72a1acd03675..1409d1003101 100644
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -827,12 +827,9 @@ static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
>  
>  static int mem_open(struct inode *inode, struct file *file)
>  {
> -	int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
> -
> -	/* OK to pass negative loff_t, we can catch out-of-range */
> -	file->f_mode |= FMODE_UNSIGNED_OFFSET;
> -
> -	return ret;
> +	if (WARN_ON_ONCE(!(file->f_op->fop_flags & FOP_UNSIGNED_OFFSET)))
> +		return -EINVAL;
> +	return __mem_open(inode, file, PTRACE_MODE_ATTACH);
>  }
>  
>  static ssize_t mem_rw(struct file *file, char __user *buf,
> @@ -932,6 +929,7 @@ static const struct file_operations proc_mem_operations = {
>  	.write		= mem_write,
>  	.open		= mem_open,
>  	.release	= mem_release,
> +	.fop_flags	= FOP_UNSIGNED_OFFSET,
>  };
>  
>  static int environ_open(struct inode *inode, struct file *file)
> diff --git a/fs/read_write.c b/fs/read_write.c
> index 90e283b31ca1..89d4af0e3b93 100644
> --- a/fs/read_write.c
> +++ b/fs/read_write.c
> @@ -36,7 +36,7 @@ EXPORT_SYMBOL(generic_ro_fops);
>  
>  static inline bool unsigned_offsets(struct file *file)
>  {
> -	return file->f_mode & FMODE_UNSIGNED_OFFSET;
> +	return file->f_op->fop_flags & FOP_UNSIGNED_OFFSET;
>  }
>  
>  /**
> diff --git a/include/drm/drm_accel.h b/include/drm/drm_accel.h
> index f4d3784b1dce..41c78b7d712c 100644
> --- a/include/drm/drm_accel.h
> +++ b/include/drm/drm_accel.h
> @@ -28,7 +28,8 @@
>  	.poll		= drm_poll,\
>  	.read		= drm_read,\
>  	.llseek		= noop_llseek, \
> -	.mmap		= drm_gem_mmap
> +	.mmap		= drm_gem_mmap, \
> +	.fop_flags	= FOP_UNSIGNED_OFFSET
>  
>  /**
>   * DEFINE_DRM_ACCEL_FOPS() - macro to generate file operations for accelerators drivers
> diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
> index bae4865b2101..d8b86df2ec0d 100644
> --- a/include/drm/drm_gem.h
> +++ b/include/drm/drm_gem.h
> @@ -447,7 +447,8 @@ struct drm_gem_object {
>  	.poll		= drm_poll,\
>  	.read		= drm_read,\
>  	.llseek		= noop_llseek,\
> -	.mmap		= drm_gem_mmap
> +	.mmap		= drm_gem_mmap, \
> +	.fop_flags	= FOP_UNSIGNED_OFFSET
>  
>  /**
>   * DEFINE_DRM_GEM_FOPS() - macro to generate file operations for GEM drivers
> diff --git a/include/drm/drm_gem_dma_helper.h b/include/drm/drm_gem_dma_helper.h
> index a827bde494f6..f2678e7ecb98 100644
> --- a/include/drm/drm_gem_dma_helper.h
> +++ b/include/drm/drm_gem_dma_helper.h
> @@ -267,6 +267,7 @@ unsigned long drm_gem_dma_get_unmapped_area(struct file *filp,
>  		.read		= drm_read,\
>  		.llseek		= noop_llseek,\
>  		.mmap		= drm_gem_mmap,\
> +		.fop_flags = FOP_UNSIGNED_OFFSET, \
>  		DRM_GEM_DMA_UNMAPPED_AREA_FOPS \
>  	}
>  
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index fd34b5755c0b..40ebfa09112c 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -146,8 +146,7 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
>  /* Expect random access pattern */
>  #define FMODE_RANDOM		((__force fmode_t)(1 << 12))
>  
> -/* File is huge (eg. /dev/mem): treat loff_t as unsigned */
> -#define FMODE_UNSIGNED_OFFSET	((__force fmode_t)(1 << 13))
> +/* FMODE_* bit 13 */
>  
>  /* File is opened with O_PATH; almost nothing can be done with it */
>  #define FMODE_PATH		((__force fmode_t)(1 << 14))
> @@ -2073,6 +2072,8 @@ struct file_operations {
>  #define FOP_DIO_PARALLEL_WRITE	((__force fop_flags_t)(1 << 3))
>  /* Contains huge pages */
>  #define FOP_HUGE_PAGES		((__force fop_flags_t)(1 << 4))
> +/* Treat loff_t as unsigned (e.g., /dev/mem) */
> +#define FOP_UNSIGNED_OFFSET	((__force fop_flags_t)(1 << 5))
>  
>  /* Wrap a directory iterator that needs exclusive inode access */
>  int wrap_directory_iterator(struct file *, struct dir_context *,
> diff --git a/mm/mmap.c b/mm/mmap.c
> index d0dfc85b209b..6ddb278a5ee8 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -1229,7 +1229,7 @@ static inline u64 file_mmap_size_max(struct file *file, struct inode *inode)
>  		return MAX_LFS_FILESIZE;
>  
>  	/* Special "we do even unsigned file positions" case */
> -	if (file->f_mode & FMODE_UNSIGNED_OFFSET)
> +	if (file->f_op->fop_flags & FOP_UNSIGNED_OFFSET)
>  		return 0;
>  
>  	/* Yes, random drivers might want more. But I'm tired of buggy drivers */
> 
> ---
> base-commit: 8400291e289ee6b2bf9779ff1c83a291501f017b
> change-id: 20240809-work-fop_unsigned-5f6f7734cb7b
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Re: [PATCH] fs: move FMODE_UNSIGNED_OFFSET to fop_flags

[Liviu Dudau]

Hi Christian,

> This is another flag that is statically set and doesn't need to use up
> an FMODE_* bit. Move it to ->fop_flags and free up another FMODE_* bit.
> 
> (1) mem_open() used from proc_mem_operations
> (2) adi_open() used from adi_fops
> (3) drm_open_helper():
>     (3.1) accel_open() used from DRM_ACCEL_FOPS
>     (3.2) drm_open() used from
>     (3.2.1) amdgpu_driver_kms_fops
>     (3.2.2) psb_gem_fops
>     (3.2.3) i915_driver_fops
>     (3.2.4) nouveau_driver_fops
>     (3.2.5) panthor_drm_driver_fops
>     (3.2.6) radeon_driver_kms_fops
>     (3.2.7) tegra_drm_fops
>     (3.2.8) vmwgfx_driver_fops
>     (3.2.9) xe_driver_fops
>     (3.2.10) DRM_GEM_FOPS
>     (3.2.11) DEFINE_DRM_GEM_DMA_FOPS
> (4) struct memdev sets fmode flags based on type of device opened. For
>     devices using struct mem_fops unsigned offset is used.
> 
> Mark all these file operations as FOP_UNSIGNED_OFFSET and add asserts
> into the open helper to ensure that the flag is always set.
> 
> Signed-off-by: Christian Brauner <brauner@kernel.org>

Your patch seems to be missing the panthor_drm_driver_fops changes. I've
discovered that on linux-next your patch triggers a WARN() during my testing.

I've added the following change to my local tree to fix the warning.

-- 8< -------------------------------------------
diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
index 34182f67136c1..c520f156e2d73 100644
--- a/drivers/gpu/drm/panthor/panthor_drv.c
+++ b/drivers/gpu/drm/panthor/panthor_drv.c
@@ -1383,6 +1383,7 @@ static const struct file_operations panthor_drm_driver_fops = {
 	.read = drm_read,
 	.llseek = noop_llseek,
 	.mmap = panthor_mmap,
+	.fop_flags = FOP_UNSIGNED_OFFSET,
 };
 
 #ifdef CONFIG_DEBUG_FS
-- 8< -------------------------------------------

Best regards,
Liviu

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯

Re: [PATCH] fs: move FMODE_UNSIGNED_OFFSET to fop_flags

[Christian Brauner]

On Wed, Sep 18, 2024 at 02:40:46PM GMT, Liviu Dudau wrote:
> Hi Christian,
> 
> > This is another flag that is statically set and doesn't need to use up
> > an FMODE_* bit. Move it to ->fop_flags and free up another FMODE_* bit.
> > 
> > (1) mem_open() used from proc_mem_operations
> > (2) adi_open() used from adi_fops
> > (3) drm_open_helper():
> >     (3.1) accel_open() used from DRM_ACCEL_FOPS
> >     (3.2) drm_open() used from
> >     (3.2.1) amdgpu_driver_kms_fops
> >     (3.2.2) psb_gem_fops
> >     (3.2.3) i915_driver_fops
> >     (3.2.4) nouveau_driver_fops
> >     (3.2.5) panthor_drm_driver_fops
> >     (3.2.6) radeon_driver_kms_fops
> >     (3.2.7) tegra_drm_fops
> >     (3.2.8) vmwgfx_driver_fops
> >     (3.2.9) xe_driver_fops
> >     (3.2.10) DRM_GEM_FOPS
> >     (3.2.11) DEFINE_DRM_GEM_DMA_FOPS
> > (4) struct memdev sets fmode flags based on type of device opened. For
> >     devices using struct mem_fops unsigned offset is used.
> > 
> > Mark all these file operations as FOP_UNSIGNED_OFFSET and add asserts
> > into the open helper to ensure that the flag is always set.
> > 
> > Signed-off-by: Christian Brauner <brauner@kernel.org>
> 
> Your patch seems to be missing the panthor_drm_driver_fops changes. I've
> discovered that on linux-next your patch triggers a WARN() during my testing.

Yeah, I've added a WARN_ON_ONCE() to catch such cases. Good that it worked.

> 
> I've added the following change to my local tree to fix the warning.

I would send a fixes PR soon. Do you want me to send a fix for this
along with this or are you taking this upstream soon yourself?

Re: [PATCH] fs: move FMODE_UNSIGNED_OFFSET to fop_flags

[Liviu Dudau]

On Thu, Sep 19, 2024 at 03:03:19PM +0200, Christian Brauner wrote:
> On Wed, Sep 18, 2024 at 02:40:46PM GMT, Liviu Dudau wrote:
> > Hi Christian,
> > 
> > > This is another flag that is statically set and doesn't need to use up
> > > an FMODE_* bit. Move it to ->fop_flags and free up another FMODE_* bit.
> > > 
> > > (1) mem_open() used from proc_mem_operations
> > > (2) adi_open() used from adi_fops
> > > (3) drm_open_helper():
> > >     (3.1) accel_open() used from DRM_ACCEL_FOPS
> > >     (3.2) drm_open() used from
> > >     (3.2.1) amdgpu_driver_kms_fops
> > >     (3.2.2) psb_gem_fops
> > >     (3.2.3) i915_driver_fops
> > >     (3.2.4) nouveau_driver_fops
> > >     (3.2.5) panthor_drm_driver_fops
> > >     (3.2.6) radeon_driver_kms_fops
> > >     (3.2.7) tegra_drm_fops
> > >     (3.2.8) vmwgfx_driver_fops
> > >     (3.2.9) xe_driver_fops
> > >     (3.2.10) DRM_GEM_FOPS
> > >     (3.2.11) DEFINE_DRM_GEM_DMA_FOPS
> > > (4) struct memdev sets fmode flags based on type of device opened. For
> > >     devices using struct mem_fops unsigned offset is used.
> > > 
> > > Mark all these file operations as FOP_UNSIGNED_OFFSET and add asserts
> > > into the open helper to ensure that the flag is always set.
> > > 
> > > Signed-off-by: Christian Brauner <brauner@kernel.org>
> > 
> > Your patch seems to be missing the panthor_drm_driver_fops changes. I've
> > discovered that on linux-next your patch triggers a WARN() during my testing.
> 
> Yeah, I've added a WARN_ON_ONCE() to catch such cases. Good that it worked.
> 
> > 
> > I've added the following change to my local tree to fix the warning.
> 
> I would send a fixes PR soon. Do you want me to send a fix for this
> along with this or are you taking this upstream soon yourself?

Was your series pulled into v6.12?

I will send a patch and once reviewed I will push it into the relevant drm-misc branch.

Best regards,
Liviu

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯