arm64: kexec_file: Avoid temp buffer for RNG seed

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After using get_random_bytes(), you want to wipe the buffer
afterward so the seed remains secret.

In this case, we can eliminate the temporary buffer entirely.
fdt_setprop_placeholder() returns a pointer to the property value
buffer, allowing us to put the random data directly in there without
using a temporary buffer at all.  Faster and less stack all in one.

Signed-off-by: George Spelvin <lkml@sdf.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20200330173801.GA9199@SDF.ORG
Signed-off-by: Will Deacon <will@kernel.org>

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George Spelvin 2020-03-30 17:38:01 +00:00 • committed by Will Deacon

parent 348a625dee

commit 99ee28d996

1 changed files with 4 additions and 4 deletions

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arch/arm64/kernel/machine_kexec_file.c

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