Use atomic operations consistently while writing to kubsan_slot.
Otherwise, reports might go by unnoticed.

Prodded by and ok visa@

Regularly poll and report kubsan findings using the timeout(9) API
instead of task(9). Undefined behavior can potentially be present in any
context and calling task_add() isn't always safe.

ok visa@

rework kubsan_state into simpler boolean named kubsan_cold

add missing handler for float cast overflow; caused by code in
sys/dev/pci/drm/amd/display/dc/calcs/dcn_calc_auto.c

Undefined behavior (UB) can potentially be present anywhere in the
kernel. kubsan reports findings using printf() and assuming that calling
printf() is safe in all contexts can be problematic. Instead, defer
reporting of findings to the systq task queue.

Storage for findings is allocated early in the boot process in order to
catch potential UB during boot. The same findings are reported once the
task queue subsystem has been initialized.

Feedback from kettenis@ and ok mpi@

sort struct declarations

rename struct for consistency

fix incorrect order of arguments

A source location in kubsan is an absolute path making reports quite
long. Instead, use everything after the first /sys/ segment as the path.

The latest inteldrm update brought along code making use of
__attribute__((nonnull)); which the undefined behavior sanitizer in
clang is aware of. A new handler is therefore needed in order to compile
a kernel with kubsan enabled.

ok visa@

correct LOCATION_REPORTED mask

Add kubsan(4), a undefined behavior sanitizer for the kernel. It's
capable of detecting undefined behavior at runtime and all findings are
printed to the system console, including the offending line in the
source code.

kubsan is limited to architectures using Clang as their default compiler
and is not enabled by default.

Derived from the NetBSD implementation.

ok kettenis@ visa@

Regularly poll and report kubsan findings using the timeout(9) API
instead of task(9). Undefined behavior can potentially be present in any
context and calling task_add() isn't always safe.

ok visa@

rework kubsan_state into simpler boolean named kubsan_cold

add missing handler for float cast overflow; caused by code in
sys/dev/pci/drm/amd/display/dc/calcs/dcn_calc_auto.c

Undefined behavior (UB) can potentially be present anywhere in the
kernel. kubsan reports findings using printf() and assuming that calling
printf() is safe in all contexts can be problematic. Instead, defer
reporting of findings to the systq task queue.

Storage for findings is allocated early in the boot process in order to
catch potential UB during boot. The same findings are reported once the
task queue subsystem has been initialized.

Feedback from kettenis@ and ok mpi@

sort struct declarations

rename struct for consistency

fix incorrect order of arguments

A source location in kubsan is an absolute path making reports quite
long. Instead, use everything after the first /sys/ segment as the path.

The latest inteldrm update brought along code making use of
__attribute__((nonnull)); which the undefined behavior sanitizer in
clang is aware of. A new handler is therefore needed in order to compile
a kernel with kubsan enabled.

ok visa@

correct LOCATION_REPORTED mask

Add kubsan(4), a undefined behavior sanitizer for the kernel. It's
capable of detecting undefined behavior at runtime and all findings are
printed to the system console, including the offending line in the
source code.

kubsan is limited to architectures using Clang as their default compiler
and is not enabled by default.

Derived from the NetBSD implementation.

ok kettenis@ visa@

rework kubsan_state into simpler boolean named kubsan_cold

add missing handler for float cast overflow; caused by code in
sys/dev/pci/drm/amd/display/dc/calcs/dcn_calc_auto.c

Undefined behavior (UB) can potentially be present anywhere in the
kernel. kubsan reports findings using printf() and assuming that calling
printf() is safe in all contexts can be problematic. Instead, defer
reporting of findings to the systq task queue.

Storage for findings is allocated early in the boot process in order to
catch potential UB during boot. The same findings are reported once the
task queue subsystem has been initialized.

Feedback from kettenis@ and ok mpi@

sort struct declarations

rename struct for consistency

fix incorrect order of arguments

A source location in kubsan is an absolute path making reports quite
long. Instead, use everything after the first /sys/ segment as the path.

The latest inteldrm update brought along code making use of
__attribute__((nonnull)); which the undefined behavior sanitizer in
clang is aware of. A new handler is therefore needed in order to compile
a kernel with kubsan enabled.

ok visa@

correct LOCATION_REPORTED mask

Add kubsan(4), a undefined behavior sanitizer for the kernel. It's
capable of detecting undefined behavior at runtime and all findings are
printed to the system console, including the offending line in the
source code.

kubsan is limited to architectures using Clang as their default compiler
and is not enabled by default.

Derived from the NetBSD implementation.

ok kettenis@ visa@

Undefined behavior (UB) can potentially be present anywhere in the
kernel. kubsan reports findings using printf() and assuming that calling
printf() is safe in all contexts can be problematic. Instead, defer
reporting of findings to the systq task queue.

Storage for findings is allocated early in the boot process in order to
catch potential UB during boot. The same findings are reported once the
task queue subsystem has been initialized.

Feedback from kettenis@ and ok mpi@

sort struct declarations

rename struct for consistency

fix incorrect order of arguments

A source location in kubsan is an absolute path making reports quite
long. Instead, use everything after the first /sys/ segment as the path.

The latest inteldrm update brought along code making use of
__attribute__((nonnull)); which the undefined behavior sanitizer in
clang is aware of. A new handler is therefore needed in order to compile
a kernel with kubsan enabled.

ok visa@

correct LOCATION_REPORTED mask

Add kubsan(4), a undefined behavior sanitizer for the kernel. It's
capable of detecting undefined behavior at runtime and all findings are
printed to the system console, including the offending line in the
source code.

kubsan is limited to architectures using Clang as their default compiler
and is not enabled by default.

Derived from the NetBSD implementation.

ok kettenis@ visa@

sort struct declarations

rename struct for consistency

fix incorrect order of arguments

A source location in kubsan is an absolute path making reports quite
long. Instead, use everything after the first /sys/ segment as the path.

The latest inteldrm update brought along code making use of
__attribute__((nonnull)); which the undefined behavior sanitizer in
clang is aware of. A new handler is therefore needed in order to compile
a kernel with kubsan enabled.

ok visa@

correct LOCATION_REPORTED mask

Add kubsan(4), a undefined behavior sanitizer for the kernel. It's
capable of detecting undefined behavior at runtime and all findings are
printed to the system console, including the offending line in the
source code.

kubsan is limited to architectures using Clang as their default compiler
and is not enabled by default.

Derived from the NetBSD implementation.

ok kettenis@ visa@

rename struct for consistency

fix incorrect order of arguments

A source location in kubsan is an absolute path making reports quite
long. Instead, use everything after the first /sys/ segment as the path.

The latest inteldrm update brought along code making use of
__attribute__((nonnull)); which the undefined behavior sanitizer in
clang is aware of. A new handler is therefore needed in order to compile
a kernel with kubsan enabled.

ok visa@

correct LOCATION_REPORTED mask

Add kubsan(4), a undefined behavior sanitizer for the kernel. It's
capable of detecting undefined behavior at runtime and all findings are
printed to the system console, including the offending line in the
source code.

kubsan is limited to architectures using Clang as their default compiler
and is not enabled by default.

Derived from the NetBSD implementation.

ok kettenis@ visa@

correct LOCATION_REPORTED mask

Add kubsan(4), a undefined behavior sanitizer for the kernel. It's
capable of detecting undefined behavior at runtime and all findings are
printed to the system console, including the offending line in the
source code.

kubsan is limited to architectures using Clang as their default compiler
and is not enabled by default.

Derived from the NetBSD implementation.

ok kettenis@ visa@