ktest: Sort config keys before writing config files

apply_min_config(), save_config(), and make_min_config() write CONFIG_*
lines by iterating "keys %hash" with no sort. Perl randomizes hash
iteration order per process by default, so the line order of the resulting
config files is not reproducible across otherwise identical invocations.

When two of those lines are mutually exclusive members of the same Kconfig
"choice", this can change which one "make olddefconfig" keeps,
nondeterministically, from run to run. Observed with
CONFIG_DEBUG_INFO_DWARF5 vs CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT: five
consecutive "-C" builds from identical ADD_CONFIG/MIN_CONFIG inputs
alternated between the two, which is enough to force a near-complete
rebuild each time since CONFIG_DEBUG_INFO_* affects every object's compile
flags.

Sort the keys before writing so the same inputs always produce the same
config output.

Link: https://patch.msgid.link/20261014-ktest-kconfig-perl-hash-v1-1-66201a2dee82@marliere.net
Signed-off-by: Ricardo B. Marlière (SUSE) <ricardo@marliere.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

0 files changed, 0 insertions, 0 deletions