Helge Deller had written a series of patches to fix a few
misalignemnt annotations in the kernel [0]. Three of these
patches were tagged as being stable candidates. Because of these
annotation I suggested proof of the imapact, however we did not
easily have a way to verify the value / impact of fixing a few
misaligment changes in the kernel for modules.
For the more hotpath alignment fix Helge had I suggested we could
easily test this by stress testing find_symbol() with a few set of
modules. This adds such tests to allow us to both allow us to test
the impact of such possible fix, and also while at it, let's us
test future improvements on the find_symbol() path.
Changes on this v2:
- Adds new selftest for kallsyms
- Drops patch #1 as Masahiro Yamada already applied it to linux-kbuild/fixes
- Removes stable tags
- Drops patch #3 as it was not needed
- Adds a new patch with the issues noted by Helge as a fix
to commit f3304ecd7f06 ("linux/export: use inline assembler to
populate symbol CRCs") as noted by Masahiro Yamada
- Adds selftest impact on x86_64 for patch #2, this really should
be tested on parisc though as that's an example architecture
where we could see perhaps more improvement
[0] https://lkml.kernel.org/r/20231122221814.139916-1-deller@xxxxxxxxxx
Masahiro, if there no issues feel free to take this or I can take them in
too via the modules-next tree. Lemme know!
Helge Deller (2):
modules: Ensure 64-bit alignment on __ksymtab_* sections
modules: Add missing entry for __ex_table
Luis Chamberlain (2):
selftests: add new kallsyms selftests
vmlinux.lds.h: add missing alignment for symbol CRCs
include/linux/export-internal.h | 1 +
lib/Kconfig.debug | 103 ++++++++++++++
lib/Makefile | 1 +
lib/tests/Makefile | 1 +
lib/tests/module/.gitignore | 4 +
lib/tests/module/Makefile | 15 ++
lib/tests/module/gen_test_kallsyms.sh | 128 ++++++++++++++++++
scripts/module.lds.S | 9 +-
tools/testing/selftests/module/Makefile | 12 ++
tools/testing/selftests/module/config | 3 +
tools/testing/selftests/module/find_symbol.sh | 81 +++++++++++
11 files changed, 354 insertions(+), 4 deletions(-)
create mode 100644 lib/tests/Makefile
create mode 100644 lib/tests/module/.gitignore
create mode 100644 lib/tests/module/Makefile
create mode 100755 lib/tests/module/gen_test_kallsyms.sh
create mode 100644 tools/testing/selftests/module/Makefile
create mode 100644 tools/testing/selftests/module/config
create mode 100755 tools/testing/selftests/module/find_symbol.sh
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2.42.0
