1 files changed, 77 insertions, 4 deletions

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 03fa07ad45d9..8a68179a98a3 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -5,7 +5,8 @@
  * This software may be used and distributed according to the terms
  * of the GNU General Public License, incorporated herein by reference.
  *
- * Usage: nm -n vmlinux | scripts/kallsyms [--all-symbols] > symbols.S
+ * Usage: kallsyms [--all-symbols] [--absolute-percpu]
+ *                         [--base-relative] in.map > out.S
  *
  *      Table compression uses all the unused char codes on the symbols and
  *  maps these to the most used substrings (tokens). For instance, it might
@@ -49,6 +50,7 @@ _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 +79,7 @@ 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 +91,7 @@ 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 +413,65 @@ 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 +557,7 @@ 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 +598,15 @@ 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 +645,7 @@ 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 +770,7 @@ 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 +890,7 @@ 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},
 			{},
 		};