Re: [PATCH v3 08/26] kernel/fork: Annotate static information into meminspect

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] Invalid physical address translation for kernel symbol in meminspect.
--

--- Patch [8]: [PATCH v3 08/26] kernel/fork: Annotate static information into meminspect ---
commit 1636f69c14cba35cc52768f137946c4cd0a44fdc
Author: Eugen Hristev <ehristev@kernel.org>

kernel/fork: Annotate static information into meminspect

This commit annotates the vital static variable nr_threads into the
meminspect inspection table. The annotated information is stored in a
dedicated meminspect section for later retrieval.

> diff --git a/kernel/fork.c b/kernel/fork.c
> index 175c73bbe2bfc..ec99066eedd24 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c

[ ... ]

> @@ -142,6 +144,7 @@
>   */
>  unsigned long total_forks;	/* Handle normal Linux uptimes. */
>  int nr_threads;			/* The idle threads do not count.. */
> +MEMINSPECT_SIMPLE_ENTRY(nr_threads);
 
[Severity: High]
This is a pre-existing issue, but adding this annotation exposes a bug in the
meminspect framework.

When MEMINSPECT_SIMPLE_ENTRY(nr_threads) is evaluated, the kernel symbol
nr_threads is passed to the framework. During boot, the framework processes
these entries and attempts a physical address translation:

kernel/meminspect/meminspect.c:meminspect_prepare_table() {
    ...
    inspect_entries[e->id].pa = virt_to_phys(inspect_entries[e->id].va);
    ...
}

Does this translation work correctly for kernel symbols? Using virt_to_phys()
on a kernel symbol (which resides in the kernel text/data mapping rather than
the linear map) can return an invalid physical address or trigger a panic on
architectures like x86_64 and arm64 when CONFIG_DEBUG_VIRTUAL is enabled.

Could the underlying framework be updated to use __pa_symbol() for these
statically registered entries instead?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260708-meminspect-v3-v3-0-7aa5a0a74d5c@oss.qualcomm.com?part=8