panic_qr: use new #[export] macro

This validates at compile time that the signatures match what is in the
header file. It highlights one annoyance with the compile-time check,
which is that it can o

panic_qr: use new #[export] macro

This validates at compile time that the signatures match what is in the
header file. It highlights one annoyance with the compile-time check,
which is that it can only be used with functions marked unsafe.

If the function is not unsafe, then this error is emitted:

error[E0308]: `if` and `else` have incompatible types
--> <linux>/drivers/gpu/drm/drm_panic_qr.rs:987:19
|
986 | #[export]
| --------- expected because of this
987 | pub extern "C" fn drm_panic_qr_max_data_size(version: u8, url_len: usize) -> usize {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ expected unsafe fn, found safe fn
|
= note: expected fn item `unsafe extern "C" fn(_, _) -> _ {kernel::bindings::drm_panic_qr_max_data_size}`
found fn item `extern "C" fn(_, _) -> _ {drm_panic_qr_max_data_size}`

The signature declarations are moved to a header file so it can be
included in the Rust bindings helper, and the extern keyword is removed
as it is unnecessary.

Reviewed-by: Andreas Hindborg <[email protected]>
Reviewed-by: Tamir Duberstein <[email protected]>
Acked-by: Simona Vetter <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Alice Ryhl <[email protected]>
Reviewed-by: Jocelyn Falempe <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Fixed `rustfmt`. Moved on top the unsafe requirement comment to follow
the usual style, and slightly reworded it for clarity. Formatted
bindings helper comment. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

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drm/panic: Better binary encoding in QR code

The current encoding, is done by converting 13bits of input into 4
decimal digits, that are then encoded efficiently using the numeric
encoding of the QR

drm/panic: Better binary encoding in QR code

The current encoding, is done by converting 13bits of input into 4
decimal digits, that are then encoded efficiently using the numeric
encoding of the QR code specification.
The Fido v2.2 specification [1] uses a similar approach for its
QR-initiated authentication. The only difference is that it converts
7 bytes (56bits) of input into 17 decimal digits. The benefit is that
the algorithm doesn't require to split input bytes into 13bits chunk,
and the ratio is a bit better.
This improvement was proposed by Jó Ágila Bitsch in [2].
drm_panic is still young, and the QR code feature is not widely used,
so it's still time to switch to a common algorithm, shared with a
widely used standard.
I also changed the name of the url parameter, from zl= to z=, so the
website can keep backward compatibility if needed.

[1] https://fidoalliance.org/specs/fido-v2.2-rd-20230321/fido-client-to-authenticator-protocol-v2.2-rd-20230321.html#hybrid-qr-initiated
[2] https://github.com/kdj0c/panic_report/issues/2

Signed-off-by: Jocelyn Falempe <[email protected]>
Acked-by: Maxime Ripard <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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drm/panic: Move drawing functions to drm_draw

Move the color conversions, blit and fill functions to drm_draw.c,
so that they can be re-used by drm_log.
drm_draw is internal to the drm subsystem, an

drm/panic: Move drawing functions to drm_draw

Move the color conversions, blit and fill functions to drm_draw.c,
so that they can be re-used by drm_log.
drm_draw is internal to the drm subsystem, and shouldn't be used by
gpu drivers.

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

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drm/panic: Add ABGR2101010 support

Add support for ABGR2101010, used by the nouveau driver.

Signed-off-by: Jocelyn Falempe <[email protected]>
Reviewed-by: Javier Martinez Canillas <javierm@redha

drm/panic: Add ABGR2101010 support

Add support for ABGR2101010, used by the nouveau driver.

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

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drm/panic: Add a QR code panic screen

This patch adds a new panic screen, with a QR code and the kmsg data
embedded.
If DRM_PANIC_SCREEN_QR_CODE_URL is set, then the kmsg data will be
compressed wit

drm/panic: Add a QR code panic screen

This patch adds a new panic screen, with a QR code and the kmsg data
embedded.
If DRM_PANIC_SCREEN_QR_CODE_URL is set, then the kmsg data will be
compressed with zlib and encoded as a numerical segment, and appended
to the URL as a URL parameter. This allows to save space, and put
about ~7500 bytes of kmsg data, in a V40 QR code.
Linux distributions can customize the URL, and put a web frontend to
directly open a bug report with the kmsg data.

Otherwise the kmsg data will be encoded as a binary segment (ie raw
ascii) and only a maximum of 2953 bytes of kmsg data will be
available in the QR code.

You can also limit the QR code size with DRM_PANIC_SCREEN_QR_VERSION.

Signed-off-by: Jocelyn Falempe <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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drm/panic: Simplify logo handling

Move logo rectangle initialisation, and logo drawing in separate
functions, so they can be re-used by different panic screens.
It prepares the introduction of the Q

drm/panic: Simplify logo handling

Move logo rectangle initialisation, and logo drawing in separate
functions, so they can be re-used by different panic screens.
It prepares the introduction of the QR code panic screen.

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

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drm/rect: Add drm_rect_overlap()

Check if two rectangles overlap.
It's a bit similar to drm_rect_intersect() but this won't modify
the rectangle.
Simplifies a bit drm_panic.

Signed-off-by: Jocelyn

drm/rect: Add drm_rect_overlap()

Check if two rectangles overlap.
It's a bit similar to drm_rect_intersect() but this won't modify
the rectangle.
Simplifies a bit drm_panic.

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

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drm/panic: Add integer scaling to blit()

Add a parameter to the blit function, to upscale the image.
This is necessary to draw a QR code, otherwise, the pixels are
usually too small to be readable b

drm/panic: Add integer scaling to blit()

Add a parameter to the blit function, to upscale the image.
This is necessary to draw a QR code, otherwise, the pixels are
usually too small to be readable by most QR code reader.
It can also be used later for drawing fonts on high DPI display.

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

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drm/panic: Add panic description

Now that kmsg dump callback has the description parameter, use it in
the user panic screen.
This is the string passed to panic(), like "VFS: Unable to mount root
fs

drm/panic: Add panic description

Now that kmsg dump callback has the description parameter, use it in
the user panic screen.
This is the string passed to panic(), like "VFS: Unable to mount root
fs on xxx" or "Attempted to kill init! exitcode=0xxxx".
It gives a hint on why the panic occurred, without being too cryptic.

Signed-off-by: Jocelyn Falempe <[email protected]>
Reviewed-by: Thomas Zimmermann <[email protected]>
Reviewed-by: Daniel Vetter <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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drm/panic: Remove useless export symbols

drm_panic_[un]register() are called only from the core drm, so there
is no need to export them.

Suggested-by: Daniel Vetter <[email protected]>
Signed-

drm/panic: Remove useless export symbols

drm_panic_[un]register() are called only from the core drm, so there
is no need to export them.

Suggested-by: Daniel Vetter <[email protected]>
Signed-off-by: Jocelyn Falempe <[email protected]>
Reviewed-by: Daniel Vetter <[email protected]>
Reviewed-by: Thomas Zimmermann <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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drm/panic: Remove space before "!" in panic message

There is no space between the last word, and the punctuation mark in
English.

Suggested-by: Diego Viola <[email protected]>
Signed-off-by: Jo

drm/panic: Remove space before "!" in panic message

There is no space between the last word, and the punctuation mark in
English.

Suggested-by: Diego Viola <[email protected]>
Signed-off-by: Jocelyn Falempe <[email protected]>
Reviewed-by: Daniel Vetter <[email protected]>
Reviewed-by: Thomas Zimmermann <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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drm/panic: Add missing static inline to drm_panic_is_enabled()

This breaks build if DRM_PANIC is not enabled.
Also add the missing include drm_crtc_internal.h in drm_panic.c

Fixes: 9f774c42a908 ("d

drm/panic: Add missing static inline to drm_panic_is_enabled()

This breaks build if DRM_PANIC is not enabled.
Also add the missing include drm_crtc_internal.h in drm_panic.c

Fixes: 9f774c42a908 ("drm/panic: Add drm_panic_is_enabled()")
Signed-off-by: Jocelyn Falempe <[email protected]>
Reviewed-by: Michal Wajdeczko <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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drm/panic: Add drm_panic_is_enabled()

It allows to check if the drm device supports drm_panic.
Prepare the work to have better integration with fbcon and vtconsole.

Signed-off-by: Jocelyn Falempe <

drm/panic: Add drm_panic_is_enabled()

It allows to check if the drm device supports drm_panic.
Prepare the work to have better integration with fbcon and vtconsole.

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

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printk: Add a short description string to kmsg_dump()

kmsg_dump doesn't forward the panic reason string to the kmsg_dumper
callback.
This patch adds a new struct kmsg_dump_detail, that will hold the

printk: Add a short description string to kmsg_dump()

kmsg_dump doesn't forward the panic reason string to the kmsg_dumper
callback.
This patch adds a new struct kmsg_dump_detail, that will hold the
reason and description, and pass it to the dump() callback.

To avoid updating all kmsg_dump() call, it adds a kmsg_dump_desc()
function and a macro for backward compatibility.

I've written this for drm_panic, but it can be useful for other
kmsg_dumper.
It allows to see the panic reason, like "sysrq triggered crash"
or "VFS: Unable to mount root fs on xxxx" on the drm panic screen.

v2:
* Use a struct kmsg_dump_detail to hold the reason and description
pointer, for more flexibility if we want to add other parameters.
(Kees Cook)
* Fix powerpc/nvram_64 build, as I didn't update the forward
declaration of oops_to_nvram()

Signed-off-by: Jocelyn Falempe <[email protected]>
Acked-by: Petr Mladek <[email protected]>
Acked-by: Michael Ellerman <[email protected]> (powerpc)
Acked-by: Kees Cook <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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drm/panic: Restrict graphical logo handling to built-in

When CONFIG_DRM_PANIC=y, but CONFIG_DRM=m:

ld: drivers/gpu/drm/drm_panic.o: in function `drm_panic_setup_logo':
drivers/gpu/drm/drm_p

drm/panic: Restrict graphical logo handling to built-in

When CONFIG_DRM_PANIC=y, but CONFIG_DRM=m:

ld: drivers/gpu/drm/drm_panic.o: in function `drm_panic_setup_logo':
drivers/gpu/drm/drm_panic.c:99: multiple definition of `init_module'; drivers/gpu/drm/drm_drv.o:drivers/gpu/drm/drm_drv.c:1079: first defined here

Fix this by restricting the graphical logo handling and its
device_initcall() to the built-in case. Logos are freed during late
kernel initialization, so they are no longer available at module load
time anyway.

Fixes: 294bbd1f2697 ("drm/panic: Add support for drawing a monochrome graphical logo")
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Signed-off-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Jocelyn Falempe <[email protected]>
Signed-off-by: Jocelyn Falempe <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/4009fca99a7c05f617cc9899c6d0a5748415595d.1719391132.git.geert+renesas@glider.be

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drm/panic: Do not select DRM_KMS_HELPER

DRM core code cannot call into DRM helper code, as this would lead to
circular references in the modular case. Hence drop the selection of
DRM_KMS_HELPER. I

drm/panic: Do not select DRM_KMS_HELPER

DRM core code cannot call into DRM helper code, as this would lead to
circular references in the modular case. Hence drop the selection of
DRM_KMS_HELPER. It was unused anyway, as v10 switched from using
the DRM format helpers to its own color format conversion, cfr. commit
9544309775c3 ("drm/panic: Add support for color format conversion").

Remove the unneeded include of <drm/drm_format_helper.h>.

Fixes: bf9fb17c6672 ("drm/panic: Add a drm panic handler")
Signed-off-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Jocelyn Falempe <[email protected]>
Signed-off-by: Jocelyn Falempe <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/60155f8c939ed286e324a7c12a1daa69fe49fcf6.1719391132.git.geert+renesas@glider.be

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drm/panic: Add support for drawing a monochrome graphical logo

Re-use the existing support for boot-up logos to draw a monochrome
graphical logo in the DRM panic handler. When no suitable graphical

drm/panic: Add support for drawing a monochrome graphical logo

Re-use the existing support for boot-up logos to draw a monochrome
graphical logo in the DRM panic handler. When no suitable graphical
logo is available, the code falls back to the ASCII art penguin logo.

Note that all graphical boot-up logos are freed during late kernel
initialization, hence a copy must be made for later use.

Signed-off-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Jocelyn Falempe <[email protected]>
Signed-off-by: Jocelyn Falempe <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/3f1a5f56213f3e4584773eb2813e212b2dff6d14.1718305355.git.geert+renesas@glider.be

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drm/panic: Rename logo to logo_ascii

Rename variables related to the ASCII logo, to prepare for the advent of
support for graphical logos.

Signed-off-by: Geert Uytterhoeven <[email protected]

drm/panic: Rename logo to logo_ascii

Rename variables related to the ASCII logo, to prepare for the advent of
support for graphical logos.

Signed-off-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Jocelyn Falempe <[email protected]>
Signed-off-by: Jocelyn Falempe <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/df77372c16153655c321a290b5a3191ee2dcbc6b.1718305355.git.geert+renesas@glider.be

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drm/panic: Fix off-by-one logo size checks

Logos that are either just as wide or just as high as the display work
fine.

Fixes: bf9fb17c6672868d ("drm/panic: Add a drm panic handler")
Signed-off-by:

drm/panic: Fix off-by-one logo size checks

Logos that are either just as wide or just as high as the display work
fine.

Fixes: bf9fb17c6672868d ("drm/panic: Add a drm panic handler")
Signed-off-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Jocelyn Falempe <[email protected]>
Signed-off-by: Jocelyn Falempe <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/1c9d02463cef3eac22cfac3ac6d1adad369f367b.1718305355.git.geert+renesas@glider.be

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drm/panic: Fix uninitialized drm_scanout_buffer.set_pixel() crash

No implementations of drm_plane_helper_funcs.get_scanout_buffer() fill
in the optional drm_scanout_buffer.set_pixel() member. Hence

drm/panic: Fix uninitialized drm_scanout_buffer.set_pixel() crash

No implementations of drm_plane_helper_funcs.get_scanout_buffer() fill
in the optional drm_scanout_buffer.set_pixel() member. Hence the member
may contain non-zero garbage, causing a crash when deferencing it during
drm panic.

Fix this by pre-initializing the drm_scanout_buffer object before
calling drm_plane_helper_funcs.get_scanout_buffer().

Fixes: 24d07f114e4ec760 ("drm/panic: Add a set_pixel() callback to drm_scanout_buffer")
Signed-off-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Jocelyn Falempe <[email protected]>
Signed-off-by: Jocelyn Falempe <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/4c250d21880ca0b97e41da7b6a101bdf07e9d015.1718305355.git.geert+renesas@glider.be

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drm/panic: Add a kmsg panic screen

Add a kmsg option, which will display the last lines of kmsg,
and should be similar to fbcon.
Add a drm.panic_screen module parameter, so you can choose between
th

drm/panic: Add a kmsg panic screen

Add a kmsg option, which will display the last lines of kmsg,
and should be similar to fbcon.
Add a drm.panic_screen module parameter, so you can choose between
the different panic screens available.
two options currently, but more will be added later:
* "user": a short message telling the user to reboot the machine.
* "kmsg": fill the screen with the last lines of kmsg.

You can even change it at runtime by writing to
/sys/module/drm/parameters/panic_screen

v2:
* Use module parameter instead of Kconfig choice
(Javier Martinez Canillas)

v3:
* Add help for module parameter usage in Kconfig
(Javier Martivez Canillas)
* Fix use of font->height before checking it isn't null.
(kernel test robot, Dan Carpenter)

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

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drm/panic: Add a set_pixel() callback to drm_scanout_buffer

This allows drivers to draw the pixel, and handle tiling, or specific
color formats.

v2:
* Use fg_color for blit() functions (Javier Mar

drm/panic: Add a set_pixel() callback to drm_scanout_buffer

This allows drivers to draw the pixel, and handle tiling, or specific
color formats.

v2:
* Use fg_color for blit() functions (Javier Martinez Canillas)

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

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drm/panic: only draw the foreground color in drm_panic_blit()

The whole framebuffer is cleared, so it's useless to rewrite the
background colored pixels. It allows to simplify the drawing
functions,

drm/panic: only draw the foreground color in drm_panic_blit()

The whole framebuffer is cleared, so it's useless to rewrite the
background colored pixels. It allows to simplify the drawing
functions, and prepare the work for the set_pixel() callback.

v2:
* keep fg16/fg24/fg32 as variable name for the blit function.
* add drm_panic_is_pixel_fg() to avoid code duplication.
both suggested by Javier Martinez Canillas

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

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drm/panic: Add debugfs entry to test without triggering panic.

Add a debugfs file, so you can test drm_panic without freezing
your machine. This is unsafe, and should be enabled only for
developer o

drm/panic: Add debugfs entry to test without triggering panic.

Add a debugfs file, so you can test drm_panic without freezing
your machine. This is unsafe, and should be enabled only for
developer or tester.

To display the drm_panic screen on the device 0:
echo 1 > /sys/kernel/debug/dri/0/drm_panic_plane_0

v9:
* Create a debugfs file for each plane in the device's debugfs
directory. This allows to test for each plane of each GPU
independently.

Signed-off-by: Jocelyn Falempe <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Acked-by: Daniel Vetter <[email protected]>

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drm/panic: Add support for color format conversion

Add support for the following formats:
DRM_FORMAT_RGB565
DRM_FORMAT_RGBA5551
DRM_FORMAT_XRGB1555
DRM_FORMAT_ARGB1555
DRM_FORMAT_RGB888
DRM_FORMAT_X

drm/panic: Add support for color format conversion

Add support for the following formats:
DRM_FORMAT_RGB565
DRM_FORMAT_RGBA5551
DRM_FORMAT_XRGB1555
DRM_FORMAT_ARGB1555
DRM_FORMAT_RGB888
DRM_FORMAT_XRGB8888
DRM_FORMAT_ARGB8888
DRM_FORMAT_XBGR8888
DRM_FORMAT_XRGB2101010
DRM_FORMAT_ARGB2101010

v10:
* move and simplify the functions from the drm format helper to drm_panic

v12:
* Use array for map and pitch in struct drm_scanout_buffer
to support multi-planar format later. (Thomas Zimmermann)

Signed-off-by: Jocelyn Falempe <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Acked-by: Daniel Vetter <[email protected]>

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