Re: [RFC PATCH 1/2] firmware: qcom: scm: Add QSEECOM app loading and shutdown

[Haozhen Li]

Hi Konrad,

Thanks for pointing these out.

You were completely right about the 4 GiB claim. I probed it on
sc8280xp by OR-ing bit 32 into an otherwise valid image address handed
to APP_START: a firmware reading only the low 32 bits would have
loaded from the untouched address and succeeded, but the call came
back with an explicit error (result 0xffffffffffffffd1, mapped by the
kernel to -EINVAL) instead. There is no silent truncation on this
firmware, and the universal claim in v1 was simply wrong.

Since I am withdrawing this series in favor of Dawid's upcoming RFC
(see the cover-letter thread), all of your feedback -- the
reverse-Christmas-tree sorting, the overflow-safe comparison form you
suggested (img_len > SZ_4G - img_phys), and reframing the 4 GiB check
as defensive hardening -- will go into a PR against his tree instead
of a v2 from me.

Best regards,
Haozhen Li