linux/lib/tests/module/gen_test_kallsyms.sh

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#!/usr/bin/env bash
selftests: add new kallsyms selftests We lack find_symbol() selftests, so add one. This let's us stress test improvements easily on find_symbol() or optimizations. It also inherently allows us to test the limits of kallsyms on Linux today. We test a pathalogical use case for kallsyms by introducing modules which are automatically written for us with a larger number of symbols. We have 4 kallsyms 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 By using anything much larger than KALLSYSMS_NUMSYMS as 10,000 and KALLSYMS_SCALE_FACTOR of 8 we segfault today. So we're capped at around 160000 symbols somehow today. We can inpsect that issue at our leasure later, but for now the real value to this test is that this will easily allow us to test improvements on find_symbol(). We want to enable this test on allyesmodconfig builds so we can't use this combination, so instead just use a safe value for now and be informative on the Kconfig symbol documentation about where our thresholds are for testers. We default then to KALLSYSMS_NUMSYMS of just 100 and KALLSYMS_SCALE_FACTOR of 8. On x86_64 we can use perf, for other architectures we just use 'time' and allow for customizations. For example a future enhancements could be done for parisc to check for unaligned accesses which triggers a special special exception handler assembler code inside the kernel. The negative impact on performance is so large on parisc that it keeps track of its accesses on /proc/cpuinfo as UAH: IRQ: CPU0 CPU1 3: 1332 0 SuperIO ttyS0 7: 1270013 0 SuperIO pata_ns87415 64: 320023012 320021431 CPU timer 65: 17080507 20624423 CPU IPI UAH: 10948640 58104 Unaligned access handler traps While at it, this tidies up lib/ test modules to allow us to have a new directory for them. The amount of test modules under lib/ is insane. This should also hopefully showcase how to start doing basic self module writing code, which may be more useful for more complex cases later in the future. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-21 12:11:44 -07:00
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')
FIRST_B_LOOKUP=1
if [[ $NUM_SYMS -gt 2 ]]; then
FIRST_B_LOOKUP=$((NUM_SYMS/2))
fi
selftests: add new kallsyms selftests We lack find_symbol() selftests, so add one. This let's us stress test improvements easily on find_symbol() or optimizations. It also inherently allows us to test the limits of kallsyms on Linux today. We test a pathalogical use case for kallsyms by introducing modules which are automatically written for us with a larger number of symbols. We have 4 kallsyms 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 By using anything much larger than KALLSYSMS_NUMSYMS as 10,000 and KALLSYMS_SCALE_FACTOR of 8 we segfault today. So we're capped at around 160000 symbols somehow today. We can inpsect that issue at our leasure later, but for now the real value to this test is that this will easily allow us to test improvements on find_symbol(). We want to enable this test on allyesmodconfig builds so we can't use this combination, so instead just use a safe value for now and be informative on the Kconfig symbol documentation about where our thresholds are for testers. We default then to KALLSYSMS_NUMSYMS of just 100 and KALLSYMS_SCALE_FACTOR of 8. On x86_64 we can use perf, for other architectures we just use 'time' and allow for customizations. For example a future enhancements could be done for parisc to check for unaligned accesses which triggers a special special exception handler assembler code inside the kernel. The negative impact on performance is so large on parisc that it keeps track of its accesses on /proc/cpuinfo as UAH: IRQ: CPU0 CPU1 3: 1332 0 SuperIO ttyS0 7: 1270013 0 SuperIO pata_ns87415 64: 320023012 320021431 CPU timer 65: 17080507 20624423 CPU IPI UAH: 10948640 58104 Unaligned access handler traps While at it, this tidies up lib/ test modules to allow us to have a new directory for them. The amount of test modules under lib/ is insane. This should also hopefully showcase how to start doing basic self module writing code, which may be more useful for more complex cases later in the future. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-21 12:11:44 -07:00
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
tests/module/gen_test_kallsyms.sh: use 0 value for variables Use 0 for the values as we use them for the return value on init to keep the test modules simple. This fixes a splat reported do_init_module: 'test_kallsyms_b'->init suspiciously returned 255, it should follow 0/-E convention do_init_module: loading module anyway... CPU: 5 UID: 0 PID: 1873 Comm: modprobe Not tainted 6.12.0-rc3+ #4 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 2024.08-1 09/18/2024 Call Trace: <TASK> dump_stack_lvl+0x56/0x80 do_init_module.cold+0x21/0x26 init_module_from_file+0x88/0xf0 idempotent_init_module+0x108/0x300 __x64_sys_finit_module+0x5a/0xb0 do_syscall_64+0x4b/0x110 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f4f3a718839 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff> RSP: 002b:00007fff97d1a9e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 RAX: ffffffffffffffda RBX: 000055b94001ab90 RCX: 00007f4f3a718839 RDX: 0000000000000000 RSI: 000055b910e68a10 RDI: 0000000000000004 RBP: 0000000000000000 R08: 00007f4f3a7f1b20 R09: 000055b94001c5b0 R10: 0000000000000040 R11: 0000000000000246 R12: 000055b910e68a10 R13: 0000000000040000 R14: 000055b94001ad60 R15: 0000000000000000 </TASK> do_init_module: 'test_kallsyms_b'->init suspiciously returned 255, it should follow 0/-E convention do_init_module: loading module anyway... CPU: 1 UID: 0 PID: 1884 Comm: modprobe Not tainted 6.12.0-rc3+ #4 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 2024.08-1 09/18/2024 Call Trace: <TASK> dump_stack_lvl+0x56/0x80 do_init_module.cold+0x21/0x26 init_module_from_file+0x88/0xf0 idempotent_init_module+0x108/0x300 __x64_sys_finit_module+0x5a/0xb0 do_syscall_64+0x4b/0x110 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7ffaa5d18839 Reported-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-11-06 00:17:21 +00:00
printf "int auto_test_%s_%010d = 0;\n" $PREFIX $i
selftests: add new kallsyms selftests We lack find_symbol() selftests, so add one. This let's us stress test improvements easily on find_symbol() or optimizations. It also inherently allows us to test the limits of kallsyms on Linux today. We test a pathalogical use case for kallsyms by introducing modules which are automatically written for us with a larger number of symbols. We have 4 kallsyms 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 By using anything much larger than KALLSYSMS_NUMSYMS as 10,000 and KALLSYMS_SCALE_FACTOR of 8 we segfault today. So we're capped at around 160000 symbols somehow today. We can inpsect that issue at our leasure later, but for now the real value to this test is that this will easily allow us to test improvements on find_symbol(). We want to enable this test on allyesmodconfig builds so we can't use this combination, so instead just use a safe value for now and be informative on the Kconfig symbol documentation about where our thresholds are for testers. We default then to KALLSYSMS_NUMSYMS of just 100 and KALLSYMS_SCALE_FACTOR of 8. On x86_64 we can use perf, for other architectures we just use 'time' and allow for customizations. For example a future enhancements could be done for parisc to check for unaligned accesses which triggers a special special exception handler assembler code inside the kernel. The negative impact on performance is so large on parisc that it keeps track of its accesses on /proc/cpuinfo as UAH: IRQ: CPU0 CPU1 3: 1332 0 SuperIO ttyS0 7: 1270013 0 SuperIO pata_ns87415 64: 320023012 320021431 CPU timer 65: 17080507 20624423 CPU IPI UAH: 10948640 58104 Unaligned access handler traps While at it, this tidies up lib/ test modules to allow us to have a new directory for them. The amount of test modules under lib/ is insane. This should also hopefully showcase how to start doing basic self module writing code, which may be more useful for more complex cases later in the future. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-21 12:11:44 -07:00
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" $FIRST_B_LOOKUP
selftests: add new kallsyms selftests We lack find_symbol() selftests, so add one. This let's us stress test improvements easily on find_symbol() or optimizations. It also inherently allows us to test the limits of kallsyms on Linux today. We test a pathalogical use case for kallsyms by introducing modules which are automatically written for us with a larger number of symbols. We have 4 kallsyms 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 By using anything much larger than KALLSYSMS_NUMSYMS as 10,000 and KALLSYMS_SCALE_FACTOR of 8 we segfault today. So we're capped at around 160000 symbols somehow today. We can inpsect that issue at our leasure later, but for now the real value to this test is that this will easily allow us to test improvements on find_symbol(). We want to enable this test on allyesmodconfig builds so we can't use this combination, so instead just use a safe value for now and be informative on the Kconfig symbol documentation about where our thresholds are for testers. We default then to KALLSYSMS_NUMSYMS of just 100 and KALLSYMS_SCALE_FACTOR of 8. On x86_64 we can use perf, for other architectures we just use 'time' and allow for customizations. For example a future enhancements could be done for parisc to check for unaligned accesses which triggers a special special exception handler assembler code inside the kernel. The negative impact on performance is so large on parisc that it keeps track of its accesses on /proc/cpuinfo as UAH: IRQ: CPU0 CPU1 3: 1332 0 SuperIO ttyS0 7: 1270013 0 SuperIO pata_ns87415 64: 320023012 320021431 CPU timer 65: 17080507 20624423 CPU IPI UAH: 10948640 58104 Unaligned access handler traps While at it, this tidies up lib/ test modules to allow us to have a new directory for them. The amount of test modules under lib/ is insane. This should also hopefully showcase how to start doing basic self module writing code, which may be more useful for more complex cases later in the future. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-21 12:11:44 -07:00
echo "static int auto_runtime_test(void)"
echo "{"
printf "\nreturn auto_test_a_%010d;\n" $FIRST_B_LOOKUP
selftests: add new kallsyms selftests We lack find_symbol() selftests, so add one. This let's us stress test improvements easily on find_symbol() or optimizations. It also inherently allows us to test the limits of kallsyms on Linux today. We test a pathalogical use case for kallsyms by introducing modules which are automatically written for us with a larger number of symbols. We have 4 kallsyms 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 By using anything much larger than KALLSYSMS_NUMSYMS as 10,000 and KALLSYMS_SCALE_FACTOR of 8 we segfault today. So we're capped at around 160000 symbols somehow today. We can inpsect that issue at our leasure later, but for now the real value to this test is that this will easily allow us to test improvements on find_symbol(). We want to enable this test on allyesmodconfig builds so we can't use this combination, so instead just use a safe value for now and be informative on the Kconfig symbol documentation about where our thresholds are for testers. We default then to KALLSYSMS_NUMSYMS of just 100 and KALLSYMS_SCALE_FACTOR of 8. On x86_64 we can use perf, for other architectures we just use 'time' and allow for customizations. For example a future enhancements could be done for parisc to check for unaligned accesses which triggers a special special exception handler assembler code inside the kernel. The negative impact on performance is so large on parisc that it keeps track of its accesses on /proc/cpuinfo as UAH: IRQ: CPU0 CPU1 3: 1332 0 SuperIO ttyS0 7: 1270013 0 SuperIO pata_ns87415 64: 320023012 320021431 CPU timer 65: 17080507 20624423 CPU IPI UAH: 10948640 58104 Unaligned access handler traps While at it, this tidies up lib/ test modules to allow us to have a new directory for them. The amount of test modules under lib/ is insane. This should also hopefully showcase how to start doing basic self module writing code, which may be more useful for more complex cases later in the future. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-21 12:11:44 -07:00
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");
MODULE_DESCRIPTION("Test module for kallsyms");
selftests: add new kallsyms selftests We lack find_symbol() selftests, so add one. This let's us stress test improvements easily on find_symbol() or optimizations. It also inherently allows us to test the limits of kallsyms on Linux today. We test a pathalogical use case for kallsyms by introducing modules which are automatically written for us with a larger number of symbols. We have 4 kallsyms 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 By using anything much larger than KALLSYSMS_NUMSYMS as 10,000 and KALLSYMS_SCALE_FACTOR of 8 we segfault today. So we're capped at around 160000 symbols somehow today. We can inpsect that issue at our leasure later, but for now the real value to this test is that this will easily allow us to test improvements on find_symbol(). We want to enable this test on allyesmodconfig builds so we can't use this combination, so instead just use a safe value for now and be informative on the Kconfig symbol documentation about where our thresholds are for testers. We default then to KALLSYSMS_NUMSYMS of just 100 and KALLSYMS_SCALE_FACTOR of 8. On x86_64 we can use perf, for other architectures we just use 'time' and allow for customizations. For example a future enhancements could be done for parisc to check for unaligned accesses which triggers a special special exception handler assembler code inside the kernel. The negative impact on performance is so large on parisc that it keeps track of its accesses on /proc/cpuinfo as UAH: IRQ: CPU0 CPU1 3: 1332 0 SuperIO ttyS0 7: 1270013 0 SuperIO pata_ns87415 64: 320023012 320021431 CPU timer 65: 17080507 20624423 CPU IPI UAH: 10948640 58104 Unaligned access handler traps While at it, this tidies up lib/ test modules to allow us to have a new directory for them. The amount of test modules under lib/ is insane. This should also hopefully showcase how to start doing basic self module writing code, which may be more useful for more complex cases later in the future. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-21 12:11:44 -07:00
____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