Norman Feske 935bb36fe4 base: fix child destruction while close requested
This patch fixes a corner case where a child is destructed while a
asynchronous close request to a sibling server is still pending.

The child immediately discarded the session ID as the end of the
close-session processing, assuming that this ID is never to be needed
again. The session-state continues to exist to handle asynchrous close
protocol with the server.

However, if the child is destructed at this point (before the server
responded to the session request), the destruction of the child would
not cover the discharging of the session state because the session state
was no longer be part of the client's ID space. So once the asynchronous
close response from the server came in, the session state contained
stale information, in particular a stale closed_callback pointer.

The patch fixes the problem by deferring the discarding of the client ID
to the point where the session state is actually destructed. So the
session of a pending close response is covered by the child destructor.

Thanks to Pirmin Duss for reporting this issue along with a test
scenario for reproducing it!

Fixes #4039
2021-03-12 12:01:38 +01:00
..
2019-11-19 14:17:29 +01:00
2021-02-23 12:07:18 +01:00
2021-02-23 12:07:18 +01:00
2020-06-29 14:22:28 +02:00
2021-02-23 12:07:18 +01:00

This is generic part of the Genode implementation. It consists of two parts:

:_Core_: is the ultimate root of the Genode application tree
  and provides abstractions for the lowest-level hardware resources
  such as RAM, ROM, CPU, and generic device access. All generic parts of Core
  can be found here - for system-specific implementations refer to the
  appropriate 'base-<system>' directory.

:_Base libraries and protocols_: that are used by each Genode component
  to interact with other components. This is the glue that holds everything
  together.

_Core_ may export information about the hardware platform by an ROM
called 'platform_info'. Depending on the platform, e.g. ARM or x86 or riscv,
and depending on the boot mode and boot loader and kernel, some nodes may not
be populated.

!<platform_info>
! <acpi revision="2" rsdt="0x1fe93074" xsdt="0x1fe930e8"/>
! <boot>
!   <framebuffer phys="0x7300000" width="1024" height="768" bpp="32"/>
! </boot>
!</platform_info>

If the ACPI RSDT and XSDT physical pointer is reported by the used kernel
and/or bootloader, _Core_ may provide this information by the ROM.

If the graphic device is initialised and can be directly used by a framebuffer
driver, _Core_ may provide the physical pointer to the framebuffer, the
resolution and color depth in bits.