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Chen Pei
0ffaa1bc65
fdt_cpu_fixup() reserves a hardcoded 32 extra bytes, plus 16 more per
HART inside the "zicntr" loop. Those 32 bytes also have to cover every
"status" property rewritten to "disabled", so once more than a handful
of HARTs are disabled the fixups fail with FDT_ERR_NOSPACE (-3).
Bumping the reservation to a fixed worst case is not safe either:
fdt_open_into() cannot know how much space the caller's buffer really
has, it just trusts the requested size. As OpenSBI does not own the
memory following a device tree passed in by the previous booting stage,
over-declaring the blob risks corrupting whatever follows it.
Walk the HART nodes once without modifying them instead, and reserve
exactly what the fixups need. The read-only decision logic is factored
into fdt_cpu_fixup_needed() so the sizing and fixup passes cannot drift
apart, which also makes the per-HART fdt_open_into() redundant. Check
the return values of fdt_setprop_string() and fdt_appendprop_string()
as well, as running out of space used to fail silently.
Fixes: dd9439fbac ("lib: utils: Add a fdt_cpu_fixup() helper")
Signed-off-by: Chen Pei <cp0613@linux.alibaba.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260817084303.1232-1-cp0613@linux.alibaba.com
Signed-off-by: Anup Patel <anup@brainfault.org>