Instead of using a special bitfield use a compound of boolean
values for the generic page attributes. To reduce copy overhead,
change the corresponding functions, where Page_flags are used as
arguments, to use references.
Within the central security unit of the i.MX53 SoC, one can set protection
level of various DMA bus master requests, distinguishing them between normal,
and secure access. Although, the access level was meant to be set correctly,
the enumeration values that denoted the kind of access were incorrect. Thereby,
until now every DMA requests was set as being secure. This commit corrects
the enumeration values, and sets all DMA operations as being unsecure, accept
from the graphical subsystem which is controlled by the secure world only.
Thanks to Andrea Barisani and Andrej Rosano from Inverse Path for discovering
this bug, as well as the hardware limitation!
For a main thread a thread object is created by the CRT0 before _main gets
called so that _main can already run in a generic environment that, e.g.,
catches stack overflows as a page-fault instead of corrupting the BSS.
Additionally dynamic programs have only one CRT0 - the one of the LDSO -
which does the initialization for both LDSO and program.
ref #989
Use a bit allocator for the allocation management of thread contexts,
instead of holding allocation information within the Thread_base objects,
which lead to race conditions in the past.
Moreover, extend the Thread_base class interface with the ability to
to add additional stacks to a thread, and associate the context they're
located in with the corresponding Thread_base object. Additional stacks
can be used to do user-level scheduling with stack switching, without breaking
Genode's API.
Fixes#1024Fixes#1036
As synchronization of signal contexts is now the users business instead of
cores and the signal framework ensures that every context of a receiver gets
synchronously destructed before the destruction of the receiver itself
synchronization and thus blocking at the destruction of a kernel
receiver-object isn't necessary anymore.
ref #989
Kernel::signal_context_kill can be used by any program to halt the processing
of a signal context synchronously to prevent broken refs when core destructs
the according kernel object. In turn, Kernel::bin_signal_context doesn't block
anymore and destructs a signal context no matter if there are unacknowledged
signals. This way, cores entrypoint doesn't depend on signal acks of a
untrustworthy client anymore.
ref #989
In the future bin_* means the direct destruction of a kernel object
without any blocking. kill_* in contrast is used for bringing a
kernel object such as signal contexts synchronized into a sleeping
state from where they can be destructed without the risk of getting
broken refs in userland.
ref #989
To remap its UTCB to its context area later, a main thread needs
to know the according dataspace capability. This is done through
the start-info it receives from its creator at startup.
ref #989
