If a user has set an invalid CONFIG_DRM_PANIC_SCREEN value (such as
"qr_code" without CONFIG_DRM_PANIC_SCREEN_QR_CODE=y due to missing or
incorrect Rust dependencies), there is a panic when accessing
/sys/module/drm/parameters/panic_screen:
[ 12.218375] BUG: unable to handle page fault for address: 0000000796dd8818
[ 12.219737] #PF: supervisor read access in kernel mode
...
[ 12.227167] RIP: 0010:drm_panic_type_get+0x1b/0x30
If drm_panic_type_set() does not find a valid drm_panic_type enumeration
in drm_panic_type_map based on the provided value, it does not change
drm_panic_type from the default -1 value, which is not a valid index for
accessing drm_panic_type_map in drm_panic_type_get(), resulting in the
crash.
Validate the value of CONFIG_DRM_PANIC_SCREEN at boot time via the
return value of drm_panic_type_set() in drm_panic_init() and explicitly
fall back to the default of "user" with a message to the user so that
they can adjust their configuration or fix missing dependencies.
[ 0.800697] Unsupported value for CONFIG_DRM_PANIC_SCREEN ('qr_code'), falling back to 'user'...
Fixes: e85e9ccf3f ("drm/panic: Report invalid or unsupported panic modes")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Signed-off-by: Tvrtko Ursulin <tursulin@ursulin.net>
Link: https://lore.kernel.org/r/20260105-drm_panic-handle-invalid-drm_panic_screen-v1-1-55228bd4b0f8@kernel.org
Currently the user can write anything into the drm.panic_screen modparam,
either at runtime via sysfs, or as a kernel boot time argument. Invalid
strings will be silently accepted and ignored at use time by defaulting to
the 'user' panic mode.
Let instead add some validation in order to have immediate feedback when
something has been mistyped, or not compiled in.
For example during kernel boot:
Booting kernel: `bsod' invalid for parameter `drm.panic_screen'
Or at runtime:
# echo -n bsod > /sys/module/drm/parameters/panic_screen
-bash: echo: write error: Invalid argument
Change of behavior is that when invalid mode is attempted to be
configured, currently the code will default to the 'user' mode, while with
this change the code will ignore it, and default to the mode set at kernel
build time via CONFIG_DRM_PANIC_SCREEN.
While at it lets also fix the module parameter description to include all
compiled in modes.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: Jocelyn Falempe <jfalempe@redhat.com>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Signed-off-by: Tvrtko Ursulin <tursulin@ursulin.net>
Link: https://lore.kernel.org/r/20251127090349.92717-1-tvrtko.ursulin@igalia.com
When using page list framebuffer, and using RGB888 format, some
pixels can cross the page boundaries, and this case was not handled,
leading to writing 1 or 2 bytes on the next virtual address.
Add a check and a specific function to handle this case.
Fixes: c9ff280879 ("drm/panic: Add support to scanout buffer as array of pages")
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20251009122955.562888-7-jfalempe@redhat.com
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
In the unlikely case that the screen is tiny, and smaller than the
font width, it leads to a divide by 0:
draw_line_with_wrap()
chars_per_row = sb->width / font->width = 0
line_wrap.len = line->len % chars_per_row;
This will trigger a divide by 0
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20251009122955.562888-6-jfalempe@redhat.com
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Fix the compile-time warnings
drivers/gpu/drm/drm_atomic.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_atomic_helper.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_atomic_state_helper.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_atomic_uapi.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_auth.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_buddy.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_color_mgmt.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_connector.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_damage_helper.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_debugfs_crc.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_drv.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_edid.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_exec.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_fb_dma_helper.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_file.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_flip_work.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_format_helper.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_gpusvm.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_gpuvm.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_managed.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_mipi_dbi.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_mipi_dsi.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_mode_config.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_modeset_helper.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_modeset_lock.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_panic.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_plane.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_plane_helper.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_print.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_privacy_screen.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_self_refresh_helper.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_simple_kms_helper.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_suballoc.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_syncobj.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_vblank_work.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_vma_manager.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/drm_writeback.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/lib/drm_random.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
drivers/gpu/drm/tests/drm_kunit_helpers.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: a934a57a42 ("scripts/misc-check: check missing #include <linux/export.h> when W=1")
Reviewed-by: André Almeida <andrealmeid@igalia.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20250612121633.229222-3-tzimmermann@suse.de
Pull Rust updates from Miguel Ojeda:
"Toolchain and infrastructure:
- Extract the 'pin-init' API from the 'kernel' crate and make it into
a standalone crate.
In order to do this, the contents are rearranged so that they can
easily be kept in sync with the version maintained out-of-tree that
other projects have started to use too (or plan to, like QEMU).
This will reduce the maintenance burden for Benno, who will now
have his own sub-tree, and will simplify future expected changes
like the move to use 'syn' to simplify the implementation.
- Add '#[test]'-like support based on KUnit.
We already had doctests support based on KUnit, which takes the
examples in our Rust documentation and runs them under KUnit.
Now, we are adding the beginning of the support for "normal" tests,
similar to those the '#[test]' tests in userspace Rust. For
instance:
#[kunit_tests(my_suite)]
mod tests {
#[test]
fn my_test() {
assert_eq!(1 + 1, 2);
}
}
Unlike with doctests, the 'assert*!'s do not map to the KUnit
assertion APIs yet.
- Check Rust signatures at compile time for functions called from C
by name.
In particular, introduce a new '#[export]' macro that can be placed
in the Rust function definition. It will ensure that the function
declaration on the C side matches the signature on the Rust
function:
#[export]
pub unsafe extern "C" fn my_function(a: u8, b: i32) -> usize {
// ...
}
The macro essentially forces the compiler to compare the types of
the actual Rust function and the 'bindgen'-processed C signature.
These cases are rare so far. In the future, we may consider
introducing another tool, 'cbindgen', to generate C headers
automatically. Even then, having these functions explicitly marked
may be a good idea anyway.
- Enable the 'raw_ref_op' Rust feature: it is already stable, and
allows us to use the new '&raw' syntax, avoiding a couple macros.
After everyone has migrated, we will disallow the macros.
- Pass the correct target to 'bindgen' on Usermode Linux.
- Fix 'rusttest' build in macOS.
'kernel' crate:
- New 'hrtimer' module: add support for setting up intrusive timers
without allocating when starting the timer. Add support for
'Pin<Box<_>>', 'Arc<_>', 'Pin<&_>' and 'Pin<&mut _>' as pointer
types for use with timer callbacks. Add support for setting clock
source and timer mode.
- New 'dma' module: add a simple DMA coherent allocator abstraction
and a test sample driver.
- 'list' module: make the linked list 'Cursor' point between
elements, rather than at an element, which is more convenient to us
and allows for cursors to empty lists; and document it with
examples of how to perform common operations with the provided
methods.
- 'str' module: implement a few traits for 'BStr' as well as the
'strip_prefix()' method.
- 'sync' module: add 'Arc::as_ptr'.
- 'alloc' module: add 'Box::into_pin'.
- 'error' module: extend the 'Result' documentation, including a few
examples on different ways of handling errors, a warning about
using methods that may panic, and links to external documentation.
'macros' crate:
- 'module' macro: add the 'authors' key to support multiple authors.
The original key will be kept until everyone has migrated.
Documentation:
- Add error handling sections.
MAINTAINERS:
- Add Danilo Krummrich as reviewer of the Rust "subsystem".
- Add 'RUST [PIN-INIT]' entry with Benno Lossin as maintainer. It has
its own sub-tree.
- Add sub-tree for 'RUST [ALLOC]'.
- Add 'DMA MAPPING HELPERS DEVICE DRIVER API [RUST]' entry with
Abdiel Janulgue as primary maintainer. It will go through the
sub-tree of the 'RUST [ALLOC]' entry.
- Add 'HIGH-RESOLUTION TIMERS [RUST]' entry with Andreas Hindborg as
maintainer. It has its own sub-tree.
And a few other cleanups and improvements"
* tag 'rust-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (71 commits)
rust: dma: add `Send` implementation for `CoherentAllocation`
rust: macros: fix `make rusttest` build on macOS
rust: block: refactor to use `&raw mut`
rust: enable `raw_ref_op` feature
rust: uaccess: name the correct function
rust: rbtree: fix comments referring to Box instead of KBox
rust: hrtimer: add maintainer entry
rust: hrtimer: add clocksource selection through `ClockId`
rust: hrtimer: add `HrTimerMode`
rust: hrtimer: implement `HrTimerPointer` for `Pin<Box<T>>`
rust: alloc: add `Box::into_pin`
rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&mut T>`
rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&T>`
rust: hrtimer: add `hrtimer::ScopedHrTimerPointer`
rust: hrtimer: add `UnsafeHrTimerPointer`
rust: hrtimer: allow timer restart from timer handler
rust: str: implement `strip_prefix` for `BStr`
rust: str: implement `AsRef<BStr>` for `[u8]` and `BStr`
rust: str: implement `Index` for `BStr`
rust: str: implement `PartialEq` for `BStr`
...
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 <a.hindborg@kernel.org>
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Simona Vetter <simona.vetter@ffwll.ch>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20250303-export-macro-v3-5-41fbad85a27f@google.com
[ 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 <ojeda@kernel.org>
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 <jfalempe@redhat.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240822073852.562286-5-jfalempe@redhat.com
Nathan ChancellorandTvrtko Ursulin
Jocelyn Falempe
Francesco VallaandJocelyn Falempe
Maxime Ripard
Tvrtko UrsulinandTvrtko Ursulin
Thomas Zimmermann
Linus Torvalds
Alice RyhlandMiguel Ojeda