Currently when portio_list MemoryRegions are freed using portio_list_destroy() the RCU
thread segfaults generating a backtrace similar to that below:
#0 0x5555599a34b6 in phys_section_destroy ../softmmu/physmem.c:996
#1 0x5555599a37a3 in phys_sections_free ../softmmu/physmem.c:1011
#2 0x5555599b24aa in address_space_dispatch_free ../softmmu/physmem.c:2430
#3 0x55555996a283 in flatview_destroy ../softmmu/memory.c:292
#4 0x55555a2cb9fb in call_rcu_thread ../util/rcu.c:284
#5 0x55555a29b71d in qemu_thread_start ../util/qemu-thread-posix.c:541
#6 0x7ffff4a0cea6 in start_thread nptl/pthread_create.c:477
#7 0x7ffff492ca2e in __clone (/lib/x86_64-linux-gnu/libc.so.6+0xfca2e)
The problem here is that portio_list_destroy() unparents the portio_list
MemoryRegions causing them to be freed immediately, however the flatview
still has a reference to the MemoryRegion and so causes a use-after-free
segfault when the RCU thread next updates the flatview.
Solve the lifetime issue by making MemoryRegionPortioList the owner of the
portio_list MemoryRegions, and then reparenting them to the portio_list
owner. This ensures that they can be accessed as QOM children via the
portio_list owner, yet the MemoryRegionPortioList owns the refcount.
Update portio_list_destroy() to unparent the MemoryRegion from the
portio_list owner (while keeping mrpio->mr live until finalization of the
MemoryRegionPortioList), so that the portio_list MemoryRegions remain
allocated until flatview_destroy() removes the final refcount upon the
next flatview update.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230419151652.362717-4-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The aim of QOMification is so that the lifetime of the MemoryRegionPortioList
structure can be managed using QOM's in-built refcounting instead of having to
handle this manually.
Due to the use of an opaque pointer it isn't possible to model the new
TYPE_MEMORY_REGION_PORTIO_LIST directly using QOM properties, however since
use of the new object is restricted to the portio API we can simply set the
opaque pointer (and the heap-allocated port list) internally.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230419151652.362717-3-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In order to facilitate a conversion of MemoryRegionPortioList to a QOM object
move the allocation of MemoryRegionPortioList ports to the heap instead of
using a variable-length member at the end of the MemoryRegionPortioList
structure.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230419151652.362717-2-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit c7f419f584 moved softmmu-only files out of the root
directory, but forgot to move the trace events, which should
no longer be generated to "trace-root.h". Fix that by adding
softmmu/trace-events.
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Claudio Fontana <cfontana@suse.de>
Message-id: 20200805130221.24487-1-philmd@redhat.com
[Rebased onto meson.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Meson doesn't enjoy the same flexibility we have with Make in choosing
the include path. In particular the tracing headers are using
$(build_root)/$(<D).
In order to keep the include directives unchanged,
the simplest solution is to generate headers with patterns like
"trace/trace-audio.h" and place forwarding headers in the source tree
such that for example "audio/trace.h" includes "trace/trace-audio.h".
This patch is too ugly to be applied to the Makefiles now. It's only
a way to separate the changes to the tracing header files from the
Meson rewrite of the tracing logic.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
move arch_init, balloon, cpus, ioport, memory, memory_mapping, qtest.
They are all specific to CONFIG_SOFTMMU.
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20200629093504.3228-2-cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
