modules changes for v6.2-rc1

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
This commit is contained in:
Linus Torvalds 2022-12-13 14:05:39 -08:00
commit 3ba2c3ff98
16 changed files with 841 additions and 44 deletions

View File

@ -66,9 +66,12 @@ static inline void *dereference_symbol_descriptor(void *ptr)
}
#ifdef CONFIG_KALLSYMS
unsigned long kallsyms_sym_address(int idx);
int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
unsigned long),
void *data);
int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long),
const char *name, void *data);
/* Lookup the address for a symbol. Returns 0 if not found. */
unsigned long kallsyms_lookup_name(const char *name);
@ -168,6 +171,12 @@ static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct
{
return -EOPNOTSUPP;
}
static inline int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long),
const char *name, void *data)
{
return -EOPNOTSUPP;
}
#endif /*CONFIG_KALLSYMS*/
static inline void print_ip_sym(const char *loglvl, unsigned long ip)

View File

@ -827,7 +827,6 @@ void *dereference_module_function_descriptor(struct module *mod, void *ptr)
#ifdef CONFIG_SYSFS
extern struct kset *module_kset;
extern struct kobj_type module_ktype;
extern int module_sysfs_initialized;
#endif /* CONFIG_SYSFS */
#define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)

View File

@ -1723,6 +1723,19 @@ config KALLSYMS
symbolic stack backtraces. This increases the size of the kernel
somewhat, as all symbols have to be loaded into the kernel image.
config KALLSYMS_SELFTEST
bool "Test the basic functions and performance of kallsyms"
depends on KALLSYMS
default n
help
Test the basic functions and performance of some interfaces, such as
kallsyms_lookup_name. It also calculates the compression rate of the
kallsyms compression algorithm for the current symbol set.
Start self-test automatically after system startup. Suggest executing
"dmesg | grep kallsyms_selftest" to collect test results. "finish" is
displayed in the last line, indicating that the test is complete.
config KALLSYMS_ALL
bool "Include all symbols in kallsyms"
depends on DEBUG_KERNEL && KALLSYMS

View File

@ -69,6 +69,7 @@ endif
obj-$(CONFIG_UID16) += uid16.o
obj-$(CONFIG_MODULE_SIG_FORMAT) += module_signature.o
obj-$(CONFIG_KALLSYMS) += kallsyms.o
obj-$(CONFIG_KALLSYMS_SELFTEST) += kallsyms_selftest.o
obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
obj-$(CONFIG_CRASH_CORE) += crash_core.o
obj-$(CONFIG_KEXEC_CORE) += kexec_core.o

View File

@ -146,7 +146,7 @@ static unsigned int get_symbol_offset(unsigned long pos)
return name - kallsyms_names;
}
static unsigned long kallsyms_sym_address(int idx)
unsigned long kallsyms_sym_address(int idx)
{
if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE))
return kallsyms_addresses[idx];
@ -187,26 +187,100 @@ static bool cleanup_symbol_name(char *s)
return false;
}
static int compare_symbol_name(const char *name, char *namebuf)
{
int ret;
ret = strcmp(name, namebuf);
if (!ret)
return ret;
if (cleanup_symbol_name(namebuf) && !strcmp(name, namebuf))
return 0;
return ret;
}
static unsigned int get_symbol_seq(int index)
{
unsigned int i, seq = 0;
for (i = 0; i < 3; i++)
seq = (seq << 8) | kallsyms_seqs_of_names[3 * index + i];
return seq;
}
static int kallsyms_lookup_names(const char *name,
unsigned int *start,
unsigned int *end)
{
int ret;
int low, mid, high;
unsigned int seq, off;
char namebuf[KSYM_NAME_LEN];
low = 0;
high = kallsyms_num_syms - 1;
while (low <= high) {
mid = low + (high - low) / 2;
seq = get_symbol_seq(mid);
off = get_symbol_offset(seq);
kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
ret = compare_symbol_name(name, namebuf);
if (ret > 0)
low = mid + 1;
else if (ret < 0)
high = mid - 1;
else
break;
}
if (low > high)
return -ESRCH;
low = mid;
while (low) {
seq = get_symbol_seq(low - 1);
off = get_symbol_offset(seq);
kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
if (compare_symbol_name(name, namebuf))
break;
low--;
}
*start = low;
if (end) {
high = mid;
while (high < kallsyms_num_syms - 1) {
seq = get_symbol_seq(high + 1);
off = get_symbol_offset(seq);
kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
if (compare_symbol_name(name, namebuf))
break;
high++;
}
*end = high;
}
return 0;
}
/* Lookup the address for this symbol. Returns 0 if not found. */
unsigned long kallsyms_lookup_name(const char *name)
{
char namebuf[KSYM_NAME_LEN];
unsigned long i;
unsigned int off;
int ret;
unsigned int i;
/* Skip the search for empty string. */
if (!*name)
return 0;
for (i = 0, off = 0; i < kallsyms_num_syms; i++) {
off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
ret = kallsyms_lookup_names(name, &i, NULL);
if (!ret)
return kallsyms_sym_address(get_symbol_seq(i));
if (strcmp(namebuf, name) == 0)
return kallsyms_sym_address(i);
if (cleanup_symbol_name(namebuf) && strcmp(namebuf, name) == 0)
return kallsyms_sym_address(i);
}
return module_kallsyms_lookup_name(name);
}
@ -233,6 +307,24 @@ int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
return 0;
}
int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long),
const char *name, void *data)
{
int ret;
unsigned int i, start, end;
ret = kallsyms_lookup_names(name, &start, &end);
if (ret)
return 0;
for (i = start; !ret && i <= end; i++) {
ret = fn(data, kallsyms_sym_address(get_symbol_seq(i)));
cond_resched();
}
return ret;
}
static unsigned long get_symbol_pos(unsigned long addr,
unsigned long *symbolsize,
unsigned long *offset)

View File

@ -26,5 +26,6 @@ extern const char kallsyms_token_table[] __weak;
extern const u16 kallsyms_token_index[] __weak;
extern const unsigned int kallsyms_markers[] __weak;
extern const u8 kallsyms_seqs_of_names[] __weak;
#endif // LINUX_KALLSYMS_INTERNAL_H_

485
kernel/kallsyms_selftest.c Normal file
View File

@ -0,0 +1,485 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Test the function and performance of kallsyms
*
* Copyright (C) Huawei Technologies Co., Ltd., 2022
*
* Authors: Zhen Lei <thunder.leizhen@huawei.com> Huawei
*/
#define pr_fmt(fmt) "kallsyms_selftest: " fmt
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/random.h>
#include <linux/sched/clock.h>
#include <linux/kthread.h>
#include <linux/vmalloc.h>
#include "kallsyms_internal.h"
#include "kallsyms_selftest.h"
#define MAX_NUM_OF_RECORDS 64
struct test_stat {
int min;
int max;
int save_cnt;
int real_cnt;
int perf;
u64 sum;
char *name;
unsigned long addr;
unsigned long addrs[MAX_NUM_OF_RECORDS];
};
struct test_item {
char *name;
unsigned long addr;
};
#define ITEM_FUNC(s) \
{ \
.name = #s, \
.addr = (unsigned long)s, \
}
#define ITEM_DATA(s) \
{ \
.name = #s, \
.addr = (unsigned long)&s, \
}
static int kallsyms_test_var_bss_static;
static int kallsyms_test_var_data_static = 1;
int kallsyms_test_var_bss;
int kallsyms_test_var_data = 1;
static int kallsyms_test_func_static(void)
{
kallsyms_test_var_bss_static++;
kallsyms_test_var_data_static++;
return 0;
}
int kallsyms_test_func(void)
{
return kallsyms_test_func_static();
}
__weak int kallsyms_test_func_weak(void)
{
kallsyms_test_var_bss++;
kallsyms_test_var_data++;
return 0;
}
static struct test_item test_items[] = {
ITEM_FUNC(kallsyms_test_func_static),
ITEM_FUNC(kallsyms_test_func),
ITEM_FUNC(kallsyms_test_func_weak),
ITEM_FUNC(vmalloc),
ITEM_FUNC(vfree),
#ifdef CONFIG_KALLSYMS_ALL
ITEM_DATA(kallsyms_test_var_bss_static),
ITEM_DATA(kallsyms_test_var_data_static),
ITEM_DATA(kallsyms_test_var_bss),
ITEM_DATA(kallsyms_test_var_data),
ITEM_DATA(vmap_area_list),
#endif
};
static char stub_name[KSYM_NAME_LEN];
static int stat_symbol_len(void *data, const char *name, struct module *mod, unsigned long addr)
{
*(u32 *)data += strlen(name);
return 0;
}
static void test_kallsyms_compression_ratio(void)
{
u32 pos, off, len, num;
u32 ratio, total_size, total_len = 0;
kallsyms_on_each_symbol(stat_symbol_len, &total_len);
/*
* A symbol name cannot start with a number. This stub name helps us
* traverse the entire symbol table without finding a match. It's used
* for subsequent performance tests, and its length is the average
* length of all symbol names.
*/
memset(stub_name, '4', sizeof(stub_name));
pos = total_len / kallsyms_num_syms;
stub_name[pos] = 0;
pos = 0;
num = 0;
off = 0;
while (pos < kallsyms_num_syms) {
len = kallsyms_names[off];
num++;
off++;
pos++;
if ((len & 0x80) != 0) {
len = (len & 0x7f) | (kallsyms_names[off] << 7);
num++;
off++;
}
off += len;
}
/*
* 1. The length fields is not counted
* 2. The memory occupied by array kallsyms_token_table[] and
* kallsyms_token_index[] needs to be counted.
*/
total_size = off - num;
pos = kallsyms_token_index[0xff];
total_size += pos + strlen(&kallsyms_token_table[pos]) + 1;
total_size += 0x100 * sizeof(u16);
pr_info(" ---------------------------------------------------------\n");
pr_info("| nr_symbols | compressed size | original size | ratio(%%) |\n");
pr_info("|---------------------------------------------------------|\n");
ratio = (u32)div_u64(10000ULL * total_size, total_len);
pr_info("| %10d | %10d | %10d | %2d.%-2d |\n",
kallsyms_num_syms, total_size, total_len, ratio / 100, ratio % 100);
pr_info(" ---------------------------------------------------------\n");
}
static int lookup_name(void *data, const char *name, struct module *mod, unsigned long addr)
{
u64 t0, t1, t;
unsigned long flags;
struct test_stat *stat = (struct test_stat *)data;
local_irq_save(flags);
t0 = sched_clock();
(void)kallsyms_lookup_name(name);
t1 = sched_clock();
local_irq_restore(flags);
t = t1 - t0;
if (t < stat->min)
stat->min = t;
if (t > stat->max)
stat->max = t;
stat->real_cnt++;
stat->sum += t;
return 0;
}
static void test_perf_kallsyms_lookup_name(void)
{
struct test_stat stat;
memset(&stat, 0, sizeof(stat));
stat.min = INT_MAX;
kallsyms_on_each_symbol(lookup_name, &stat);
pr_info("kallsyms_lookup_name() looked up %d symbols\n", stat.real_cnt);
pr_info("The time spent on each symbol is (ns): min=%d, max=%d, avg=%lld\n",
stat.min, stat.max, div_u64(stat.sum, stat.real_cnt));
}
static bool match_cleanup_name(const char *s, const char *name)
{
char *p;
int len;
if (!IS_ENABLED(CONFIG_LTO_CLANG))
return false;
p = strchr(s, '.');
if (!p)
return false;
len = strlen(name);
if (p - s != len)
return false;
return !strncmp(s, name, len);
}
static int find_symbol(void *data, const char *name, struct module *mod, unsigned long addr)
{
struct test_stat *stat = (struct test_stat *)data;
if (strcmp(name, stat->name) == 0 ||
(!stat->perf && match_cleanup_name(name, stat->name))) {
stat->real_cnt++;
stat->addr = addr;
if (stat->save_cnt < MAX_NUM_OF_RECORDS) {
stat->addrs[stat->save_cnt] = addr;
stat->save_cnt++;
}
if (stat->real_cnt == stat->max)
return 1;
}
return 0;
}
static void test_perf_kallsyms_on_each_symbol(void)
{
u64 t0, t1;
unsigned long flags;
struct test_stat stat;
memset(&stat, 0, sizeof(stat));
stat.max = INT_MAX;
stat.name = stub_name;
stat.perf = 1;
local_irq_save(flags);
t0 = sched_clock();
kallsyms_on_each_symbol(find_symbol, &stat);
t1 = sched_clock();
local_irq_restore(flags);
pr_info("kallsyms_on_each_symbol() traverse all: %lld ns\n", t1 - t0);
}
static int match_symbol(void *data, unsigned long addr)
{
struct test_stat *stat = (struct test_stat *)data;
stat->real_cnt++;
stat->addr = addr;
if (stat->save_cnt < MAX_NUM_OF_RECORDS) {
stat->addrs[stat->save_cnt] = addr;
stat->save_cnt++;
}
if (stat->real_cnt == stat->max)
return 1;
return 0;
}
static void test_perf_kallsyms_on_each_match_symbol(void)
{
u64 t0, t1;
unsigned long flags;
struct test_stat stat;
memset(&stat, 0, sizeof(stat));
stat.max = INT_MAX;
stat.name = stub_name;
local_irq_save(flags);
t0 = sched_clock();
kallsyms_on_each_match_symbol(match_symbol, stat.name, &stat);
t1 = sched_clock();
local_irq_restore(flags);
pr_info("kallsyms_on_each_match_symbol() traverse all: %lld ns\n", t1 - t0);
}
static int test_kallsyms_basic_function(void)
{
int i, j, ret;
int next = 0, nr_failed = 0;
char *prefix;
unsigned short rand;
unsigned long addr, lookup_addr;
char namebuf[KSYM_NAME_LEN];
struct test_stat *stat, *stat2;
stat = kmalloc(sizeof(*stat) * 2, GFP_KERNEL);
if (!stat)
return -ENOMEM;
stat2 = stat + 1;
prefix = "kallsyms_lookup_name() for";
for (i = 0; i < ARRAY_SIZE(test_items); i++) {
addr = kallsyms_lookup_name(test_items[i].name);
if (addr != test_items[i].addr) {
nr_failed++;
pr_info("%s %s failed: addr=%lx, expect %lx\n",
prefix, test_items[i].name, addr, test_items[i].addr);
}
}
prefix = "kallsyms_on_each_symbol() for";
for (i = 0; i < ARRAY_SIZE(test_items); i++) {
memset(stat, 0, sizeof(*stat));
stat->max = INT_MAX;
stat->name = test_items[i].name;
kallsyms_on_each_symbol(find_symbol, stat);
if (stat->addr != test_items[i].addr || stat->real_cnt != 1) {
nr_failed++;
pr_info("%s %s failed: count=%d, addr=%lx, expect %lx\n",
prefix, test_items[i].name,
stat->real_cnt, stat->addr, test_items[i].addr);
}
}
prefix = "kallsyms_on_each_match_symbol() for";
for (i = 0; i < ARRAY_SIZE(test_items); i++) {
memset(stat, 0, sizeof(*stat));
stat->max = INT_MAX;
stat->name = test_items[i].name;
kallsyms_on_each_match_symbol(match_symbol, test_items[i].name, stat);
if (stat->addr != test_items[i].addr || stat->real_cnt != 1) {
nr_failed++;
pr_info("%s %s failed: count=%d, addr=%lx, expect %lx\n",
prefix, test_items[i].name,
stat->real_cnt, stat->addr, test_items[i].addr);
}
}
if (nr_failed) {
kfree(stat);
return -ESRCH;
}
for (i = 0; i < kallsyms_num_syms; i++) {
addr = kallsyms_sym_address(i);
if (!is_ksym_addr(addr))
continue;
ret = lookup_symbol_name(addr, namebuf);
if (unlikely(ret)) {
namebuf[0] = 0;
goto failed;
}
/*
* The first '.' may be the initial letter, in which case the
* entire symbol name will be truncated to an empty string in
* cleanup_symbol_name(). Do not test these symbols.
*
* For example:
* cat /proc/kallsyms | awk '{print $3}' | grep -E "^\." | head
* .E_read_words
* .E_leading_bytes
* .E_trailing_bytes
* .E_write_words
* .E_copy
* .str.292.llvm.12122243386960820698
* .str.24.llvm.12122243386960820698
* .str.29.llvm.12122243386960820698
* .str.75.llvm.12122243386960820698
* .str.99.llvm.12122243386960820698
*/
if (IS_ENABLED(CONFIG_LTO_CLANG) && !namebuf[0])
continue;
lookup_addr = kallsyms_lookup_name(namebuf);
memset(stat, 0, sizeof(*stat));
stat->max = INT_MAX;
kallsyms_on_each_match_symbol(match_symbol, namebuf, stat);
/*
* kallsyms_on_each_symbol() is too slow, randomly select some
* symbols for test.
*/
if (i >= next) {
memset(stat2, 0, sizeof(*stat2));
stat2->max = INT_MAX;
stat2->name = namebuf;
kallsyms_on_each_symbol(find_symbol, stat2);
/*
* kallsyms_on_each_symbol() and kallsyms_on_each_match_symbol()
* need to get the same traversal result.
*/
if (stat->addr != stat2->addr ||
stat->real_cnt != stat2->real_cnt ||
memcmp(stat->addrs, stat2->addrs,
stat->save_cnt * sizeof(stat->addrs[0])))
goto failed;
/*
* The average of random increments is 128, that is, one of
* them is tested every 128 symbols.
*/
get_random_bytes(&rand, sizeof(rand));
next = i + (rand & 0xff) + 1;
}
/* Need to be found at least once */
if (!stat->real_cnt)
goto failed;
/*
* kallsyms_lookup_name() returns the address of the first
* symbol found and cannot be NULL.
*/
if (!lookup_addr || lookup_addr != stat->addrs[0])
goto failed;
/*
* If the addresses of all matching symbols are recorded, the
* target address needs to be exist.
*/
if (stat->real_cnt <= MAX_NUM_OF_RECORDS) {
for (j = 0; j < stat->save_cnt; j++) {
if (stat->addrs[j] == addr)
break;
}
if (j == stat->save_cnt)
goto failed;
}
}
kfree(stat);
return 0;
failed:
pr_info("Test for %dth symbol failed: (%s) addr=%lx", i, namebuf, addr);
kfree(stat);
return -ESRCH;
}
static int test_entry(void *p)
{
int ret;
do {
schedule_timeout(5 * HZ);
} while (system_state != SYSTEM_RUNNING);
pr_info("start\n");
ret = test_kallsyms_basic_function();
if (ret) {
pr_info("abort\n");
return 0;
}
test_kallsyms_compression_ratio();
test_perf_kallsyms_lookup_name();
test_perf_kallsyms_on_each_symbol();
test_perf_kallsyms_on_each_match_symbol();
pr_info("finish\n");
return 0;
}
static int __init kallsyms_test_init(void)
{
struct task_struct *t;
t = kthread_create(test_entry, NULL, "kallsyms_test");
if (IS_ERR(t)) {
pr_info("Create kallsyms selftest task failed\n");
return PTR_ERR(t);
}
kthread_bind(t, 0);
wake_up_process(t);
return 0;
}
late_initcall(kallsyms_test_init);

View File

@ -0,0 +1,13 @@
/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef LINUX_KALLSYMS_SELFTEST_H_
#define LINUX_KALLSYMS_SELFTEST_H_
#include <linux/types.h>
extern int kallsyms_test_var_bss;
extern int kallsyms_test_var_data;
extern int kallsyms_test_func(void);
extern int kallsyms_test_func_weak(void);
#endif // LINUX_KALLSYMS_SELFTEST_H_

View File

@ -125,6 +125,24 @@ struct klp_find_arg {
unsigned long pos;
};
static int klp_match_callback(void *data, unsigned long addr)
{
struct klp_find_arg *args = data;
args->addr = addr;
args->count++;
/*
* Finish the search when the symbol is found for the desired position
* or the position is not defined for a non-unique symbol.
*/
if ((args->pos && (args->count == args->pos)) ||
(!args->pos && (args->count > 1)))
return 1;
return 0;
}
static int klp_find_callback(void *data, const char *name,
struct module *mod, unsigned long addr)
{
@ -139,18 +157,7 @@ static int klp_find_callback(void *data, const char *name,
if (args->objname && strcmp(args->objname, mod->name))
return 0;
args->addr = addr;
args->count++;
/*
* Finish the search when the symbol is found for the desired position
* or the position is not defined for a non-unique symbol.
*/
if ((args->pos && (args->count == args->pos)) ||
(!args->pos && (args->count > 1)))
return 1;
return 0;
return klp_match_callback(data, addr);
}
static int klp_find_object_symbol(const char *objname, const char *name,
@ -167,7 +174,7 @@ static int klp_find_object_symbol(const char *objname, const char *name,
if (objname)
module_kallsyms_on_each_symbol(klp_find_callback, &args);
else
kallsyms_on_each_symbol(klp_find_callback, &args);
kallsyms_on_each_match_symbol(klp_match_callback, name, &args);
/*
* Ensure an address was found. If sympos is 0, ensure symbol is unique;

View File

@ -221,9 +221,10 @@ endchoice
config MODULE_DECOMPRESS
bool "Support in-kernel module decompression"
depends on MODULE_COMPRESS_GZIP || MODULE_COMPRESS_XZ
depends on MODULE_COMPRESS_GZIP || MODULE_COMPRESS_XZ || MODULE_COMPRESS_ZSTD
select ZLIB_INFLATE if MODULE_COMPRESS_GZIP
select XZ_DEC if MODULE_COMPRESS_XZ
select ZSTD_DECOMPRESS if MODULE_COMPRESS_ZSTD
help
Support for decompressing kernel modules by the kernel itself

View File

@ -50,7 +50,7 @@ static struct page *module_get_next_page(struct load_info *info)
return page;
}
#ifdef CONFIG_MODULE_COMPRESS_GZIP
#if defined(CONFIG_MODULE_COMPRESS_GZIP)
#include <linux/zlib.h>
#define MODULE_COMPRESSION gzip
#define MODULE_DECOMPRESS_FN module_gzip_decompress
@ -114,8 +114,8 @@ static ssize_t module_gzip_decompress(struct load_info *info,
do {
struct page *page = module_get_next_page(info);
if (!page) {
retval = -ENOMEM;
if (IS_ERR(page)) {
retval = PTR_ERR(page);
goto out_inflate_end;
}
@ -141,7 +141,7 @@ out:
kfree(s.workspace);
return retval;
}
#elif CONFIG_MODULE_COMPRESS_XZ
#elif defined(CONFIG_MODULE_COMPRESS_XZ)
#include <linux/xz.h>
#define MODULE_COMPRESSION xz
#define MODULE_DECOMPRESS_FN module_xz_decompress
@ -173,8 +173,8 @@ static ssize_t module_xz_decompress(struct load_info *info,
do {
struct page *page = module_get_next_page(info);
if (!page) {
retval = -ENOMEM;
if (IS_ERR(page)) {
retval = PTR_ERR(page);
goto out;
}
@ -199,6 +199,94 @@ static ssize_t module_xz_decompress(struct load_info *info,
xz_dec_end(xz_dec);
return retval;
}
#elif defined(CONFIG_MODULE_COMPRESS_ZSTD)
#include <linux/zstd.h>
#define MODULE_COMPRESSION zstd
#define MODULE_DECOMPRESS_FN module_zstd_decompress
static ssize_t module_zstd_decompress(struct load_info *info,
const void *buf, size_t size)
{
static const u8 signature[] = { 0x28, 0xb5, 0x2f, 0xfd };
ZSTD_outBuffer zstd_dec;
ZSTD_inBuffer zstd_buf;
zstd_frame_header header;
size_t wksp_size;
void *wksp = NULL;
ZSTD_DStream *dstream;
size_t ret;
size_t new_size = 0;
int retval;
if (size < sizeof(signature) ||
memcmp(buf, signature, sizeof(signature))) {
pr_err("not a zstd compressed module\n");
return -EINVAL;
}
zstd_buf.src = buf;
zstd_buf.pos = 0;
zstd_buf.size = size;
ret = zstd_get_frame_header(&header, zstd_buf.src, zstd_buf.size);
if (ret != 0) {
pr_err("ZSTD-compressed data has an incomplete frame header\n");
retval = -EINVAL;
goto out;
}
if (header.windowSize > (1 << ZSTD_WINDOWLOG_MAX)) {
pr_err("ZSTD-compressed data has too large a window size\n");
retval = -EINVAL;
goto out;
}
wksp_size = zstd_dstream_workspace_bound(header.windowSize);
wksp = kmalloc(wksp_size, GFP_KERNEL);
if (!wksp) {
retval = -ENOMEM;
goto out;
}
dstream = zstd_init_dstream(header.windowSize, wksp, wksp_size);
if (!dstream) {
pr_err("Can't initialize ZSTD stream\n");
retval = -ENOMEM;
goto out;
}
do {
struct page *page = module_get_next_page(info);
if (!IS_ERR(page)) {
retval = PTR_ERR(page);
goto out;
}
zstd_dec.dst = kmap_local_page(page);
zstd_dec.pos = 0;
zstd_dec.size = PAGE_SIZE;
ret = zstd_decompress_stream(dstream, &zstd_dec, &zstd_buf);
kunmap(page);
retval = zstd_get_error_code(ret);
if (retval)
break;
new_size += zstd_dec.pos;
} while (zstd_dec.pos == PAGE_SIZE && ret != 0);
if (retval) {
pr_err("ZSTD-decompression failed with status %d\n", retval);
retval = -EINVAL;
goto out;
}
retval = new_size;
out:
kfree(wksp);
return retval;
}
#else
#error "Unexpected configuration for CONFIG_MODULE_DECOMPRESS"
#endif

View File

@ -85,9 +85,6 @@ struct mod_tree_root mod_data_tree __cacheline_aligned = {
};
#endif
#define module_addr_min mod_tree.addr_min
#define module_addr_max mod_tree.addr_max
struct symsearch {
const struct kernel_symbol *start, *stop;
const s32 *crcs;

View File

@ -340,7 +340,7 @@ static int mod_sysfs_init(struct module *mod)
int err;
struct kobject *kobj;
if (!module_sysfs_initialized) {
if (!module_kset) {
pr_err("%s: module sysfs not initialized\n", mod->name);
err = -EINVAL;
goto out;

View File

@ -940,7 +940,6 @@ static const struct kset_uevent_ops module_uevent_ops = {
};
struct kset *module_kset;
int module_sysfs_initialized;
static void module_kobj_release(struct kobject *kobj)
{
@ -954,7 +953,11 @@ struct kobj_type module_ktype = {
};
/*
* param_sysfs_init - wrapper for built-in params support
* param_sysfs_init - create "module" kset
*
* This must be done before the initramfs is unpacked and
* request_module() thus becomes possible, because otherwise the
* module load would fail in mod_sysfs_init.
*/
static int __init param_sysfs_init(void)
{
@ -964,13 +967,25 @@ static int __init param_sysfs_init(void)
__FILE__, __LINE__);
return -ENOMEM;
}
module_sysfs_initialized = 1;
return 0;
}
subsys_initcall(param_sysfs_init);
/*
* param_sysfs_builtin_init - add sysfs version and parameter
* attributes for built-in modules
*/
static int __init param_sysfs_builtin_init(void)
{
if (!module_kset)
return -ENOMEM;
version_sysfs_builtin();
param_sysfs_builtin();
return 0;
}
subsys_initcall(param_sysfs_init);
late_initcall(param_sysfs_builtin_init);
#endif /* CONFIG_SYSFS */

View File

@ -49,6 +49,7 @@ _Static_assert(
struct sym_entry {
unsigned long long addr;
unsigned int len;
unsigned int seq;
unsigned int start_pos;
unsigned int percpu_absolute;
unsigned char sym[];
@ -77,6 +78,7 @@ static unsigned int table_size, table_cnt;
static int all_symbols;
static int absolute_percpu;
static int base_relative;
static int lto_clang;
static int token_profit[0x10000];
@ -88,7 +90,7 @@ static unsigned char best_table_len[256];
static void usage(void)
{
fprintf(stderr, "Usage: kallsyms [--all-symbols] [--absolute-percpu] "
"[--base-relative] in.map > out.S\n");
"[--base-relative] [--lto-clang] in.map > out.S\n");
exit(1);
}
@ -410,6 +412,65 @@ static int symbol_absolute(const struct sym_entry *s)
return s->percpu_absolute;
}
static char * s_name(char *buf)
{
/* Skip the symbol type */
return buf + 1;
}
static void cleanup_symbol_name(char *s)
{
char *p;
if (!lto_clang)
return;
/*
* ASCII[.] = 2e
* ASCII[0-9] = 30,39
* ASCII[A-Z] = 41,5a
* ASCII[_] = 5f
* ASCII[a-z] = 61,7a
*
* As above, replacing '.' with '\0' does not affect the main sorting,
* but it helps us with subsorting.
*/
p = strchr(s, '.');
if (p)
*p = '\0';
}
static int compare_names(const void *a, const void *b)
{
int ret;
char sa_namebuf[KSYM_NAME_LEN];
char sb_namebuf[KSYM_NAME_LEN];
const struct sym_entry *sa = *(const struct sym_entry **)a;
const struct sym_entry *sb = *(const struct sym_entry **)b;
expand_symbol(sa->sym, sa->len, sa_namebuf);
expand_symbol(sb->sym, sb->len, sb_namebuf);
cleanup_symbol_name(s_name(sa_namebuf));
cleanup_symbol_name(s_name(sb_namebuf));
ret = strcmp(s_name(sa_namebuf), s_name(sb_namebuf));
if (!ret) {
if (sa->addr > sb->addr)
return 1;
else if (sa->addr < sb->addr)
return -1;
/* keep old order */
return (int)(sa->seq - sb->seq);
}
return ret;
}
static void sort_symbols_by_name(void)
{
qsort(table, table_cnt, sizeof(table[0]), compare_names);
}
static void write_src(void)
{
unsigned int i, k, off;
@ -495,6 +556,7 @@ static void write_src(void)
for (i = 0; i < table_cnt; i++) {
if ((i & 0xFF) == 0)
markers[i >> 8] = off;
table[i]->seq = i;
/* There cannot be any symbol of length zero. */
if (table[i]->len == 0) {
@ -535,6 +597,15 @@ static void write_src(void)
free(markers);
sort_symbols_by_name();
output_label("kallsyms_seqs_of_names");
for (i = 0; i < table_cnt; i++)
printf("\t.byte 0x%02x, 0x%02x, 0x%02x\n",
(unsigned char)(table[i]->seq >> 16),
(unsigned char)(table[i]->seq >> 8),
(unsigned char)(table[i]->seq >> 0));
printf("\n");
output_label("kallsyms_token_table");
off = 0;
for (i = 0; i < 256; i++) {
@ -573,7 +644,7 @@ static void forget_symbol(const unsigned char *symbol, int len)
}
/* do the initial token count */
static void build_initial_tok_table(void)
static void build_initial_token_table(void)
{
unsigned int i;
@ -698,7 +769,7 @@ static void insert_real_symbols_in_table(void)
static void optimize_token_table(void)
{
build_initial_tok_table();
build_initial_token_table();
insert_real_symbols_in_table();
@ -818,6 +889,7 @@ int main(int argc, char **argv)
{"all-symbols", no_argument, &all_symbols, 1},
{"absolute-percpu", no_argument, &absolute_percpu, 1},
{"base-relative", no_argument, &base_relative, 1},
{"lto-clang", no_argument, &lto_clang, 1},
{},
};

View File

@ -156,6 +156,10 @@ kallsyms()
kallsymopt="${kallsymopt} --base-relative"
fi
if is_enabled CONFIG_LTO_CLANG; then
kallsymopt="${kallsymopt} --lto-clang"
fi
info KSYMS ${2}
scripts/kallsyms ${kallsymopt} ${1} > ${2}
}