diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 7315f643817ae1021f1e4b3dd27b424f49e3f761..b5929721fc639df3db7819b5bcad50d71f13442f 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2903,6 +2903,111 @@ config TEST_KMOD If unsure, say N. +config TEST_RUNTIME + bool + +config TEST_RUNTIME_MODULE + bool + +config TEST_KALLSYMS + tristate "module kallsyms find_symbol() test" + depends on m + select TEST_RUNTIME + select TEST_RUNTIME_MODULE + select TEST_KALLSYMS_A + select TEST_KALLSYMS_B + select TEST_KALLSYMS_C + select TEST_KALLSYMS_D + help + This allows us to stress test find_symbol() through the kallsyms + used to place symbols on the kernel ELF kallsyms and modules kallsyms + where we place kernel symbols such as exported symbols. + + We have four test modules: + + A: has KALLSYSMS_NUMSYMS exported symbols + B: uses one of A's symbols + C: adds KALLSYMS_SCALE_FACTOR * KALLSYSMS_NUMSYMS exported + D: adds 2 * the symbols than C + + We stress test find_symbol() through two means: + + 1) Upon load of B it will trigger simplify_symbols() to look for the + one symbol it uses from the module A with tons of symbols. This is an + indirect way for us to have B call resolve_symbol_wait() upon module + load. This will eventually call find_symbol() which will eventually + try to find the symbols used with find_exported_symbol_in_section(). + find_exported_symbol_in_section() uses bsearch() so a binary search + for each symbol. Binary search will at worst be O(log(n)) so the + larger TEST_MODULE_KALLSYSMS the worse the search. + + 2) The selftests should load C first, before B. Upon B's load towards + the end right before we call module B's init routine we get + complete_formation() called on the module. That will first check + for duplicate symbols with the call to verify_exported_symbols(). + That is when we'll force iteration on module C's insane symbol list. + Since it has 10 * KALLSYMS_NUMSYMS it means we can first test + just loading B without C. The amount of time it takes to load C Vs + B can give us an idea of the impact growth of the symbol space and + give us projection. Module A only uses one symbol from B so to allow + this scaling in module C to be proportional, if it used more symbols + then the first test would be doing more and increasing just the + search space would be slightly different. The last module, module D + will just increase the search space by twice the number of symbols in + C so to allow for full projects. + + tools/testing/selftests/module/find_symbol.sh + + The current defaults will incur a build delay of about 7 minutes + on an x86_64 with only 8 cores. Enable this only if you want to + stress test find_symbol() with thousands of symbols. At the same + time this is also useful to test building modules with thousands of + symbols, and if BTF is enabled this also stress tests adding BTF + information for each module. Currently enabling many more symbols + will segfault the build system. + + If unsure, say N. + +if TEST_KALLSYMS + +config TEST_KALLSYMS_A + tristate + depends on m + +config TEST_KALLSYMS_B + tristate + depends on m + +config TEST_KALLSYMS_C + tristate + depends on m + +config TEST_KALLSYMS_D + tristate + depends on m + +config TEST_KALLSYMS_NUMSYMS + int "test kallsyms number of symbols" + default 100 + help + The number of symbols to create on TEST_KALLSYMS_A, only one of which + module TEST_KALLSYMS_B will use. This also will be used + for how many symbols TEST_KALLSYMS_C will have, scaled up by + TEST_KALLSYMS_SCALE_FACTOR. Note that setting this to 10,000 will + trigger a segfault today, don't use anything close to it unless + you are aware that this should not be used for automated build tests. + +config TEST_KALLSYMS_SCALE_FACTOR + int "test kallsyms scale factor" + default 8 + help + How many more unusued symbols will TEST_KALLSYSMS_C have than + TEST_KALLSYMS_A. If 8, then module C will have 8 * syms + than module A. Then TEST_KALLSYMS_D will have double the amount + of symbols than C so to allow projections. + +endif # TEST_KALLSYMS + config TEST_DEBUG_VIRTUAL tristate "Test CONFIG_DEBUG_VIRTUAL feature" depends on DEBUG_VIRTUAL diff --git a/lib/Makefile b/lib/Makefile index 773adf88af41665b2419202e5427e0513c6becae..ae720c7eb996bbc4606a1e35b25d1c4c1f64b654 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -96,6 +96,7 @@ obj-$(CONFIG_TEST_XARRAY) += test_xarray.o obj-$(CONFIG_TEST_MAPLE_TREE) += test_maple_tree.o obj-$(CONFIG_TEST_PARMAN) += test_parman.o obj-$(CONFIG_TEST_KMOD) += test_kmod.o +obj-$(CONFIG_TEST_RUNTIME) += tests/ obj-$(CONFIG_TEST_DEBUG_VIRTUAL) += test_debug_virtual.o obj-$(CONFIG_TEST_MEMCAT_P) += test_memcat_p.o obj-$(CONFIG_TEST_OBJAGG) += test_objagg.o diff --git a/lib/tests/Makefile b/lib/tests/Makefile new file mode 100644 index 0000000000000000000000000000000000000000..8e4f42cb9c54f7e62a8ce3a9015363ec169457ac --- /dev/null +++ b/lib/tests/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_TEST_RUNTIME_MODULE) += module/ diff --git a/lib/tests/module/.gitignore b/lib/tests/module/.gitignore new file mode 100644 index 0000000000000000000000000000000000000000..8be7891b250fe4cee83bbda4b54a2a4283f6631d --- /dev/null +++ b/lib/tests/module/.gitignore @@ -0,0 +1,4 @@ +test_kallsyms_a.c +test_kallsyms_b.c +test_kallsyms_c.c +test_kallsyms_d.c diff --git a/lib/tests/module/Makefile b/lib/tests/module/Makefile new file mode 100644 index 0000000000000000000000000000000000000000..af5c27b996cb15d2f48218755b3ea3d81ffd7280 --- /dev/null +++ b/lib/tests/module/Makefile @@ -0,0 +1,15 @@ +obj-$(CONFIG_TEST_KALLSYMS_A) += test_kallsyms_a.o +obj-$(CONFIG_TEST_KALLSYMS_B) += test_kallsyms_b.o +obj-$(CONFIG_TEST_KALLSYMS_C) += test_kallsyms_c.o +obj-$(CONFIG_TEST_KALLSYMS_D) += test_kallsyms_d.o + +$(obj)/%.c: FORCE + @$(kecho) " GEN $@" + $(Q)$(srctree)/lib/tests/module/gen_test_kallsyms.sh $@\ + $(CONFIG_TEST_KALLSYMS_NUMSYMS) \ + $(CONFIG_TEST_KALLSYMS_SCALE_FACTOR) + +clean-files += test_kallsyms_a.c +clean-files += test_kallsyms_b.c +clean-files += test_kallsyms_c.c +clean-files += test_kallsyms_d.c diff --git a/lib/tests/module/gen_test_kallsyms.sh b/lib/tests/module/gen_test_kallsyms.sh new file mode 100755 index 0000000000000000000000000000000000000000..e85f10dc11bdf5d725335ba9cffd9279ec8e6bf1 --- /dev/null +++ b/lib/tests/module/gen_test_kallsyms.sh @@ -0,0 +1,128 @@ +#!/bin/bash + +TARGET=$(basename $1) +DIR=lib/tests/module +TARGET="$DIR/$TARGET" +NUM_SYMS=$2 +SCALE_FACTOR=$3 +TEST_TYPE=$(echo $TARGET | sed -e 's|lib/tests/module/test_kallsyms_||g') +TEST_TYPE=$(echo $TEST_TYPE | sed -e 's|.c||g') + +gen_template_module_header() +{ + cat <<____END_MODULE +// SPDX-License-Identifier: GPL-2.0-or-later OR copyleft-next-0.3.1 +/* + * Copyright (C) 2023 Luis Chamberlain <mcgrof@kernel.org> + * + * Automatically generated code for testing, do not edit manually. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/printk.h> + +____END_MODULE +} + +gen_num_syms() +{ + PREFIX=$1 + NUM=$2 + for i in $(seq 1 $NUM); do + printf "int auto_test_%s_%010d = 0xff;\n" $PREFIX $i + printf "EXPORT_SYMBOL_GPL(auto_test_%s_%010d);\n" $PREFIX $i + done + echo +} + +gen_template_module_data_a() +{ + gen_num_syms a $1 + cat <<____END_MODULE +static int auto_runtime_test(void) +{ + return 0; +} + +____END_MODULE +} + +gen_template_module_data_b() +{ + printf "\nextern int auto_test_a_%010d;\n\n" 28 + echo "static int auto_runtime_test(void)" + echo "{" + printf "\nreturn auto_test_a_%010d;\n" 28 + echo "}" +} + +gen_template_module_data_c() +{ + gen_num_syms c $1 + cat <<____END_MODULE +static int auto_runtime_test(void) +{ + return 0; +} + +____END_MODULE +} + +gen_template_module_data_d() +{ + gen_num_syms d $1 + cat <<____END_MODULE +static int auto_runtime_test(void) +{ + return 0; +} + +____END_MODULE +} + +gen_template_module_exit() +{ + cat <<____END_MODULE +static int __init auto_test_module_init(void) +{ + return auto_runtime_test(); +} +module_init(auto_test_module_init); + +static void __exit auto_test_module_exit(void) +{ +} +module_exit(auto_test_module_exit); + +MODULE_AUTHOR("Luis Chamberlain <mcgrof@kernel.org>"); +MODULE_LICENSE("GPL"); +____END_MODULE +} + +case $TEST_TYPE in + a) + gen_template_module_header > $TARGET + gen_template_module_data_a $NUM_SYMS >> $TARGET + gen_template_module_exit >> $TARGET + ;; + b) + gen_template_module_header > $TARGET + gen_template_module_data_b >> $TARGET + gen_template_module_exit >> $TARGET + ;; + c) + gen_template_module_header > $TARGET + gen_template_module_data_c $((NUM_SYMS * SCALE_FACTOR)) >> $TARGET + gen_template_module_exit >> $TARGET + ;; + d) + gen_template_module_header > $TARGET + gen_template_module_data_d $((NUM_SYMS * SCALE_FACTOR * 2)) >> $TARGET + gen_template_module_exit >> $TARGET + ;; + *) + ;; +esac diff --git a/tools/testing/selftests/module/Makefile b/tools/testing/selftests/module/Makefile new file mode 100644 index 0000000000000000000000000000000000000000..6132d7ddb08b0e37279ee26de10a22f5fd37d73d --- /dev/null +++ b/tools/testing/selftests/module/Makefile @@ -0,0 +1,12 @@ +# SPDX-License-Identifier: GPL-2.0-only +# Makefile for module loading selftests + +# No binaries, but make sure arg-less "make" doesn't trigger "run_tests" +all: + +TEST_PROGS := find_symbol.sh + +include ../lib.mk + +# Nothing to clean up. +clean: diff --git a/tools/testing/selftests/module/config b/tools/testing/selftests/module/config new file mode 100644 index 0000000000000000000000000000000000000000..b0c206b1ad47d7e2231205390b3b116c6c7f6cef --- /dev/null +++ b/tools/testing/selftests/module/config @@ -0,0 +1,3 @@ +CONFIG_TEST_RUNTIME=y +CONFIG_TEST_RUNTIME_MODULE=y +CONFIG_TEST_KALLSYMS=m diff --git a/tools/testing/selftests/module/find_symbol.sh b/tools/testing/selftests/module/find_symbol.sh new file mode 100755 index 0000000000000000000000000000000000000000..140364d3c49fc912eb6846b512e65cb419f6c1ba --- /dev/null +++ b/tools/testing/selftests/module/find_symbol.sh @@ -0,0 +1,81 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0-or-later OR copyleft-next-0.3.1 +# Copyright (C) 2023 Luis Chamberlain <mcgrof@kernel.org> +# +# This is a stress test script for kallsyms through find_symbol() + +set -e + +# Kselftest framework requirement - SKIP code is 4. +ksft_skip=4 + +test_reqs() +{ + if ! which modprobe 2> /dev/null > /dev/null; then + echo "$0: You need modprobe installed" >&2 + exit $ksft_skip + fi + + if ! which kmod 2> /dev/null > /dev/null; then + echo "$0: You need kmod installed" >&2 + exit $ksft_skip + fi + + if ! which perf 2> /dev/null > /dev/null; then + echo "$0: You need perf installed" >&2 + exit $ksft_skip + fi + + uid=$(id -u) + if [ $uid -ne 0 ]; then + echo $msg must be run as root >&2 + exit $ksft_skip + fi +} + +load_mod() +{ + local STATS="-e duration_time" + STATS="$STATS -e user_time" + STATS="$STATS -e system_time" + STATS="$STATS -e page-faults" + local MOD=$1 + + local ARCH="$(uname -m)" + case "${ARCH}" in + x86_64) + perf stat $STATS $MODPROBE test_kallsyms_b + ;; + *) + time $MODPROBE test_kallsyms_b + exit 1 + ;; + esac +} + +remove_all() +{ + $MODPROBE -r test_kallsyms_b + for i in a b c d; do + $MODPROBE -r test_kallsyms_$i + done +} +test_reqs + +MODPROBE=$(</proc/sys/kernel/modprobe) + +remove_all +load_mod test_kallsyms_b +remove_all + +# Now pollute the namespace +$MODPROBE test_kallsyms_c +load_mod test_kallsyms_b + +# Now pollute the namespace with twice the number of symbols than the last time +remove_all +$MODPROBE test_kallsyms_c +$MODPROBE test_kallsyms_d +load_mod test_kallsyms_b + +exit 0