[PATCH v6 02/14] kexec: Record allocated CMA pages to fix release size mismatch

[sashiko-bot at kernel.org]

> The CMA pages allocated for a kexec segment are released using the
> segment's memsz to calculate the number of pages. However, some
> architecture loaders modify the segment's memsz after allocation
> (e.g. arm64 subtracts text_offset), causing the release function to
> free fewer pages than were originally allocated, leaking the remaining
> CMA pages.
> 
> Add a per-segment `segment_cma_pages` array to store the number of
> pages actually allocated from CMA. Populate it during
> kexec_add_buffer() using the aligned memsz, and use it in
> kimage_free_cma() to accurately release all allocated pages.
> 
> This avoids relying on the potentially modified segment->memsz and
> prevents silent CMA memory leaks.
> 
> Cc: Andrew Morton <akpm at linux-foundation.org>
> Cc: Baoquan He <baoquan.he at linux.dev>
> Cc: Mike Rapoport <rppt at kernel.org>
> Cc: Pasha Tatashin <pasha.tatashin at soleen.com>
> Cc: Pratyush Yadav <pratyush at kernel.org>
> Cc: Brian Mak <makb at juniper.net>
> Cc: Pingfan Liu <piliu at redhat.com>
> Cc: Sourabh Jain <sourabhjain at linux.ibm.com>
> Cc: Justinien Bouron <jbouron at amazon.com>
> Cc: Li Chen <me at linux.beauty>
> Cc: Breno Leitao <leitao at debian.org>
> Cc: stable at vger.kernel.org
> Link: https://sashiko.dev/#/patchset/20260729031235.2840255-1-ruanjinjie%40huawei.com
> Fixes: 07d24902977e ("kexec: enable CMA based contiguous allocation")
> Signed-off-by: Jinjie Ruan <ruanjinjie at huawei.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260921090450.807575-1-ruanjinjie@huawei.com?part=2