fbdev: Warn on incorrect framebuffer access

Test in framebuffer read, write and drawing helpers if FBINFO_VIRTFB
has been set correctly. Framebuffers in I/O memory should only be
accessed with the a

fbdev: Warn on incorrect framebuffer access

Test in framebuffer read, write and drawing helpers if FBINFO_VIRTFB
has been set correctly. Framebuffers in I/O memory should only be
accessed with the architecture's respective helpers. Framebuffers
in system memory should be accessed with the regular load and
store operations. Presumably not all drivers get this right, so we
now warn about it.

Signed-off-by: Thomas Zimmermann <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

fbdev: Validate info->screen_{base, buffer} in fb_ops implementations

Push the test for info->screen_base from fb_read() and fb_write() into
the implementations of struct fb_ops.{fb_read,fb_write}.

fbdev: Validate info->screen_{base, buffer} in fb_ops implementations

Push the test for info->screen_base from fb_read() and fb_write() into
the implementations of struct fb_ops.{fb_read,fb_write}. In cases where
the driver operates on info->screen_buffer, test this field instead.

While bothi fields, screen_base and screen_buffer, are stored in the
same location, they refer to different address spaces. For correctness,
we want to test each field in exactly the code that uses it.

v2:
* also test screen_base in pvr2fb (Geert)
* also test screen_buffer in ivtvfb, arcfb, broadsheetfb,
hecubafb, metronomefb and ssd1307fb (Geert)
* give a rational for the change (Geert)

Signed-off-by: Thomas Zimmermann <[email protected]>
Tested-by: Sui Jingfeng <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Acked-by: Helge Deller <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

fbdev: Don't re-validate info->state in fb_ops implementations

The file-op entry points fb_read() and fb_write() verify that
info->state has been set to FBINFO_STATE_RUNNING. Remove the same
test fr

fbdev: Don't re-validate info->state in fb_ops implementations

The file-op entry points fb_read() and fb_write() verify that
info->state has been set to FBINFO_STATE_RUNNING. Remove the same
test from the implementations of struct fb_ops.{fb_read,fb_write}.

v2:
* also remove test from ivtvfb, braodsheetfb, hecubafb and
metronomefb (Geert)

Signed-off-by: Thomas Zimmermann <[email protected]>
Tested-by: Sui Jingfeng <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Acked-by: Helge Deller <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

fbdev: Use screen_buffer in fb_sys_{read,write}()

Use info->screen_buffer when reading and writing framebuffers in
system memory. It's the correct pointer for this address space.

The struct fb_info

fbdev: Use screen_buffer in fb_sys_{read,write}()

Use info->screen_buffer when reading and writing framebuffers in
system memory. It's the correct pointer for this address space.

The struct fb_info has a union to store the framebuffer memory. This can
either be info->screen_base if the framebuffer is stored in I/O memory,
or info->screen_buffer if the framebuffer is stored in system memory.

Since the fb_sys_{read,write}() functions operate on the latter address
space, it is wrong to use .screen_base and .screen_buffer must be used
instead. This also gets rid of all the casting needed due to not using
the correct data type.

v2:
* add detailed commit message (Javier)

Signed-off-by: Thomas Zimmermann <[email protected]>
Tested-by: Sui Jingfeng <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Acked-by: Helge Deller <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

fbdev: Return number of bytes read or written

Always return the number of bytes read or written within the
framebuffer. Only return an errno code if framebuffer memory
was not touched. This is the s

fbdev: Return number of bytes read or written

Always return the number of bytes read or written within the
framebuffer. Only return an errno code if framebuffer memory
was not touched. This is the semantics required by POSIX and
makes fb_read() and fb_write() compatible with IGT tests. [1]

This bug has been fixed for fb_write() long ago by
commit 6a2a88668e90 ("[PATCH] fbdev: Fix return error of
fb_write"). The code in fb_read() and the corresponding fb_sys_()
helpers was forgotten.

It can happen that copy_{from, to}_user() only partially copies
the given buffer. Take this into account when calculating the
number of bytes.

v2:
* consider return value from copy_{from,to}_user() (Geert)

Signed-off-by: Thomas Zimmermann <[email protected]>
Tested-by: Sui Jingfeng <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Acked-by: Helge Deller <[email protected]>
Link: https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/blob/master/tests/fbdev.c # 1
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

fbdev: move fbdev core files to separate directory

Instead of having fbdev framework core files at the root fbdev
directory, mixed with random fbdev device drivers, move the fbdev core
files to a se

fbdev: move fbdev core files to separate directory

Instead of having fbdev framework core files at the root fbdev
directory, mixed with random fbdev device drivers, move the fbdev core
files to a separate core directory. This makes it much clearer which of
the files are actually part of the fbdev framework, and which are part
of device drivers.

Signed-off-by: Tomi Valkeinen <[email protected]>
Acked-by: Laurent Pinchart <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Acked-by: Rob Clark <[email protected]>
Acked-by: Jingoo Han <[email protected]>
Acked-by: Daniel Vetter <[email protected]>

show more ...