diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-12-13 14:05:39 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-12-13 14:05:39 -0800 |
commit | 3ba2c3ff98ea8bfb219288dbacf2a23a902c751b (patch) | |
tree | 90165b304a5b0cf50bc88883ca7a61f1cec65b8c /scripts | |
parent | 0015edd6f66172f93aa720192020138ca13ba0a6 (diff) | |
parent | 4f1354d5c6a3264c91238962d1597eef40c40419 (diff) | |
download | lwn-3ba2c3ff98ea8bfb219288dbacf2a23a902c751b.tar.gz lwn-3ba2c3ff98ea8bfb219288dbacf2a23a902c751b.zip |
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
Diffstat (limited to 'scripts')
-rw-r--r-- | scripts/kallsyms.c | 78 | ||||
-rwxr-xr-x | scripts/link-vmlinux.sh | 4 |
2 files changed, 79 insertions, 3 deletions
diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c index 03fa07ad45d9..04e04fbd9625 100644 --- a/scripts/kallsyms.c +++ b/scripts/kallsyms.c @@ -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, <o_clang, 1}, {}, }; diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 918470d768e9..32e573943cf0 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -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} } |