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
16 changed files with 841 additions and 44 deletions

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}
}