[PATCH] Include Aliases in kallsyms

From: Rusty Russell <rusty@rustcorp.com.au>

Kallsyms discards symbols with the same address, but these are sometimes
useful.  Skip this minor optimization and make kallsyms_lookup deal with
aliases

kernel/kallsyms.c

@@ -88,14 +88,20 @@ const char *kallsyms_lookup(unsigned long addr,
 			name += strlen(name) + 1;
 		}
 
-		/* Base symbol size on next symbol. */
-		if (best + 1 < kallsyms_num_syms)
-			symbol_end = kallsyms_addresses[best + 1];
-		else if (is_kernel_inittext(addr))
+		/* At worst, symbol ends at end of section. */
+		if (is_kernel_inittext(addr))
 			symbol_end = (unsigned long)_einittext;
 		else
 			symbol_end = (unsigned long)_etext;
 
+		/* Search for next non-aliased symbol */
+		for (i = best+1; i < kallsyms_num_syms; i++) {
+			if (kallsyms_addresses[i] > kallsyms_addresses[best]) {
+				symbol_end = kallsyms_addresses[i];
+				break;
+			}
+		}
+
 		*symbolsize = symbol_end - kallsyms_addresses[best];
 		*modname = NULL;
 		*offset = addr - kallsyms_addresses[best];

scripts/kallsyms.c

@@ -93,7 +93,6 @@ read_map(FILE *in)
 static void
 write_src(void)
 {
-	unsigned long long last_addr;
 	int i, valid = 0;
 	char *prev;
 
@@ -111,16 +110,12 @@ write_src(void)
 	printf(".globl kallsyms_addresses\n");
 	printf("\tALGN\n");
 	printf("kallsyms_addresses:\n");
-	for (i = 0, last_addr = 0; i < cnt; i++) {
+	for (i = 0; i < cnt; i++) {
 		if (!symbol_valid(&table[i]))
 			continue;
 
-		if (table[i].addr == last_addr)
-			continue;
-
 		printf("\tPTR\t%#llx\n", table[i].addr);
 		valid++;
-		last_addr = table[i].addr;
 	}
 	printf("\n");
 
@@ -134,20 +129,16 @@ write_src(void)
 	printf("\tALGN\n");
 	printf("kallsyms_names:\n");
 	prev = ""; 
-	for (i = 0, last_addr = 0; i < cnt; i++) {
+	for (i = 0; i < cnt; i++) {
 		int k;
 
 		if (!symbol_valid(&table[i]))
 			continue;
 
-		if (table[i].addr == last_addr)
-			continue;
-
 		for (k = 0; table[i].sym[k] && table[i].sym[k] == prev[k]; ++k)
 			; 
 
 		printf("\t.byte 0x%02x\n\t.asciz\t\"%s\"\n", k, table[i].sym + k);
-		last_addr = table[i].addr;
 		prev = table[i].sym;
 	}
 	printf("\n");