Re: [PATCH v7 01/15] arm64: kexec_file: Stop using the Image text_offset

[sashiko-bot@kernel.org]

> image_load() adds text_offset to kernel_segment->mem and subtracts it
> from kernel_segment->memsz.  For CMA backed segments this breaks the
> load path: the payload is copied to page_address(cma), which is the CMA
> base, while image->start is set to the adjusted address, so kexec jumps
> into the middle of the kernel.  kimage_map_segment() has the same
> mismatch when a segment has been moved.
> 
> The adjusted memsz also breaks the release path: the CMA pages are
> freed using segment->memsz >> PAGE_SHIFT, which is fewer than were
> allocated, leaking the tail of the allocation.
> 
> Since commit 751c263bb74f ("arm64: remove TEXT_OFFSET randomization")
> TEXT_OFFSET is always zero.  This has been upstream since v5.8, so no
> LTS kernel carries a non-zero text_offset.  Drop the adjustment and
> reject images with a non-zero value instead of booting them from a
> wrong address.  With the adjustment gone, segments stay at their CMA
> base and the release size matches the allocation.
> 
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Mike Rapoport <rppt@kernel.org>
> Link: https://lore.kernel.org/all/20260921090450.807575-2-ruanjinjie@huawei.com/
> Link: https://lore.kernel.org/all/20260921090450.807575-3-ruanjinjie@huawei.com/
> Fixes: 07d24902977e ("kexec: enable CMA based contiguous allocation")
> Suggested-by: Mike Rapoport <rppt@kernel.org>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>

Sashiko has reviewed this patch and found no issues.

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