[PATCH v2 0/1] fix dumpdtb crash with ARM machines

[Daniel Henrique Barboza]

Hi,

In this version I fixed a mem leak that was happening if the user inputs
a fdt via '-dtb'. In that case we would assign the updated FDT on top of
the existing board FDT that was already assigned to ms->fdt.

Tested as follows:

$ ./qemu-system-aarch64 -S -M virt -display none -qmp stdio
{"QMP": {"version": {"qemu": {"micro": 91, "minor": 2, "major": 7}, "package": 
"v8.0.0-rc1-37-ge573ef31e7-dirty"}, "capabilities": ["oob"]}}
{"execute": "qmp_capabilities", "arguments": {"enable": ["oob"]}}
{"return": {}}

{"execute": "dumpdtb", "arguments": {"filename": "fdt.dtb"}}
{"return": {}}

^Cqemu-system-aarch64: terminating on signal 2
{"timestamp": {"seconds": 1679603324, "microseconds": 62159}, "event": 
"SHUTDOWN", "data": {"guest": false, "reason": "host-signal"}}
$ 


$ ./qemu-system-aarch64 -S -M virt -display none -qmp stdio -dtb fdt.dtb 
{"QMP": {"version": {"qemu": {"micro": 91, "minor": 2, "major": 7}, "package": 
"v8.0.0-rc1-37-ge573ef31e7-dirty"}, "capabilities": ["oob"]}}
{"execute": "qmp_capabilities", "arguments": {"enable": ["oob"]}}
{"return": {}}

{"execute": "dumpdtb", "arguments": {"filename": "fdt.dtb"}}
{"return": {}}
^Cqemu-system-aarch64: terminating on signal 2
{"timestamp": {"seconds": 1679603344, "microseconds": 145748}, "event": 
"SHUTDOWN", "data": {"guest": false, "reason": "host-signal"}}
$ 


First we use 'dumpdtb' to dump the board FDT in fdt.dtb, then we use it as
an argument to '-dtb' and do the test again. This covers both code paths.


Changes from v1:
- g_free(ms->fdt) before load_device_tree()
- v1 link: https://lists.gnu.org/archive/html/qemu-devel/2023-03/msg05930.html

Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: qemu-arm@nongnu.org

Daniel Henrique Barboza (1):
  hw/arm: do not free machine->fdt in arm_load_dtb()

 hw/arm/boot.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

-- 
2.39.2