Tux gets for xmass improving the average lookup performance of
kallsyms_lookup_name() by 715x thanks to the work by Zhen Lei, which
upgraded our old implementation from being O(n) to O(log(n)), while also
retaining the old implementation support on /proc/kallsyms. The only
penalty was increasing the memory footprint by 3 * kallsyms_num_syms.
Folks who want to improve this further now also have a dedicated selftest
facility through KALLSYMS_SELFTEST. Since I had to start reviewing other
future kallsyms / modules enhancements by Nick Alcock (his stuff is not
merged, it requires more work) I carefully reviewed and merged Zhen Lei's
kallsyms changes through modules-next tree a bit less than a month ago.
So this has been exposed on linux-next for about a month now with no
reported regressions.
Stephen Boyd added zstd in-kernel decompression support, but the only
users of this would be folks using the load-pin LSM because otherwise
we do module docompression in userspace. This is the newest code and
was merged last week on modules-next.
We spent a lot of time analyzing and coming to grips with a proper
fix to an old modules regression which only recently came to light
(since v5.3-rc1, May 2019) but even though I merged that fix onto
modules-next last week I'm having second thoughts about it now as I was
writing about that fix in this git tag message for you, as I found a few
things we cannot quite justify there yet. So I'm going to push back to the
drawing board again there until all i's are properly dotted. Yes, it's a
regression but the issue has been there for 2 years now and it came up
because of high end CPU count, it can wait a *tiny* bit more for a proper
fix.
The only other thing with mentioning is a minor boot time optimization by
Rasmus Villemoes which deferes param_sysfs_init() to late init. The rest
is cleanups and minor fixes.
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Merge tag 'modules-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull modules updates from Luis Chamberlain:
"Tux gets for xmas an improvement to the average lookup performance of
kallsyms_lookup_name() by 715x thanks to the work by Zhen Lei, which
upgraded our old implementation from being O(n) to O(log(n)), while
also retaining the old implementation support on /proc/kallsyms.
The only penalty was increasing the memory footprint by 3 *
kallsyms_num_syms. Folks who want to improve this further now also
have a dedicated selftest facility through KALLSYMS_SELFTEST.
Stephen Boyd added zstd in-kernel decompression support, but the only
users of this would be folks using the load-pin LSM because otherwise
we do module decompression in userspace.
The only other thing with mentioning is a minor boot time optimization
by Rasmus Villemoes which deferes param_sysfs_init() to late init. The
rest is cleanups and minor fixes"
* tag 'modules-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
livepatch: Call klp_match_callback() in klp_find_callback() to avoid code duplication
module/decompress: Support zstd in-kernel decompression
kallsyms: Remove unneeded semicolon
kallsyms: Add self-test facility
livepatch: Use kallsyms_on_each_match_symbol() to improve performance
kallsyms: Add helper kallsyms_on_each_match_symbol()
kallsyms: Reduce the memory occupied by kallsyms_seqs_of_names[]
kallsyms: Correctly sequence symbols when CONFIG_LTO_CLANG=y
kallsyms: Improve the performance of kallsyms_lookup_name()
scripts/kallsyms: rename build_initial_tok_table()
module: Fix NULL vs IS_ERR checking for module_get_next_page
kernel/params.c: defer most of param_sysfs_init() to late_initcall time
module: Remove unused macros module_addr_min/max
module: remove redundant module_sysfs_initialized variable
3ba2c3ff98