Simplify kallsyms_lookup()

Several kallsyms_lookup() pass dummy arguments but only need, say, module's name. Make kallsyms_lookup() accept NULLs where possible. Also, makes picture clearer about what interfaces are needed for all symbol resolving business. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Cc: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Simplify kallsyms_lookup()
Several kallsyms_lookup() pass dummy arguments but only need, say, module's name. Make kallsyms_lookup() accept NULLs where possible. Also, makes picture clearer about what interfaces are needed for all symbol resolving business. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Cc: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Alexey Dobriyan · Linus Torvalds
1 parent ea07890a68
Showing 10 changed files with 20 additions and 28 deletions Side-by-side Diff
arch/parisc/kernel/unwind.c
arch/powerpc/xmon/xmon.c
arch/sh64/kernel/unwind.c
fs/proc/base.c
kernel/kallsyms.c
kernel/kprobes.c
kernel/lockdep.c
kernel/module.c
kernel/time/timer_list.c
kernel/time/timer_stats.c
@@ -216,11 +216,8 @@
 		/* Handle some frequent special cases.... */
 		{
 			char symname[KSYM_NAME_LEN+1];
-			char *modname;
-			unsigned long symsize, offset;
  
-			kallsyms_lookup(info->ip, &symsize, &offset,
-					&modname, symname);
+			kallsyms_lookup(info->ip, NULL, NULL, NULL, symname);
  
 			dbg("info->ip = 0x%lx, name = %s\n", info->ip, symname);
  
@@ -1217,7 +1217,6 @@
 {
 	unsigned long size, offset;
 	const char *name;
-	char *modname;
  
 	*startp = *endp = 0;
 	if (pc == 0)
@@ -1225,7 +1224,7 @@
 	if (setjmp(bus_error_jmp) == 0) {
 		catch_memory_errors = 1;
 		sync();
-		name = kallsyms_lookup(pc, &size, &offset, &modname, tmpstr);
+		name = kallsyms_lookup(pc, &size, &offset, NULL, tmpstr);
 		if (name != NULL) {
 			*startp = pc - offset;
 			*endp = pc - offset + size;
@@ -46,15 +46,15 @@
 		      struct pt_regs *regs)
 {
 	const char *sym;
-	char *modname, namebuf[128];
-	unsigned long offset, size;
+	char namebuf[128];
+	unsigned long offset;
 	unsigned long prologue = 0;
 	unsigned long fp_displacement = 0;
 	unsigned long fp_prev = 0;
 	unsigned long offset_r14 = 0, offset_r18 = 0;
 	int i, found_prologue_end = 0;
  
-	sym = kallsyms_lookup(pc, &size, &offset, &modname, namebuf);
+	sym = kallsyms_lookup(pc, NULL, &offset, NULL, namebuf);
 	if (!sym)
 		return -EINVAL;
  
@@ -278,14 +278,13 @@
  */
 static int proc_pid_wchan(struct task_struct *task, char *buffer)
 {
-	char *modname;
 	const char *sym_name;
-	unsigned long wchan, size, offset;
+	unsigned long wchan;
 	char namebuf[KSYM_NAME_LEN+1];
  
 	wchan = get_wchan(task);
  
-	sym_name = kallsyms_lookup(wchan, &size, &offset, &modname, namebuf);
+	sym_name = kallsyms_lookup(wchan, NULL, NULL, NULL, namebuf);
 	if (sym_name)
 		return sprintf(buffer, "%s", sym_name);
 	return sprintf(buffer, "%lu", wchan);
@@ -214,8 +214,10 @@
 			symbol_end = (unsigned long)_etext;
 	}
  
-	*symbolsize = symbol_end - symbol_start;
-	*offset = addr - symbol_start;
+	if (symbolsize)
+		*symbolsize = symbol_end - symbol_start;
+	if (offset)
+		*offset = addr - symbol_start;
  
 	return low;
 }
@@ -868,13 +868,13 @@
 	struct kprobe *p, *kp;
 	const char *sym = NULL;
 	unsigned int i = *(loff_t *) v;
-	unsigned long size, offset = 0;
+	unsigned long offset = 0;
 	char *modname, namebuf[128];
  
 	head = &kprobe_table[i];
 	preempt_disable();
 	hlist_for_each_entry_rcu(p, node, head, hlist) {
-		sym = kallsyms_lookup((unsigned long)p->addr, &size,
+		sym = kallsyms_lookup((unsigned long)p->addr, NULL,
 					&offset, &modname, namebuf);
 		if (p->pre_handler == aggr_pre_handler) {
 			list_for_each_entry_rcu(kp, &p->list, list)
@@ -340,10 +340,7 @@
  
 const char * __get_key_name(struct lockdep_subclass_key *key, char *str)
 {
-	unsigned long offs, size;
-	char *modname;
-
-	return kallsyms_lookup((unsigned long)key, &size, &offs, &modname, str);
+	return kallsyms_lookup((unsigned long)key, NULL, NULL, NULL, str);
 }
  
 void
@@ -2098,8 +2098,10 @@
 	if (!best)
 		return NULL;
  
-	*size = nextval - mod->symtab[best].st_value;
-	*offset = addr - mod->symtab[best].st_value;
+	if (size)
+		*size = nextval - mod->symtab[best].st_value;
+	if (offset)
+		*offset = addr - mod->symtab[best].st_value;
 	return mod->strtab + mod->symtab[best].st_name;
 }
  
@@ -40,11 +40,9 @@
 {
 	unsigned long addr = (unsigned long)sym;
 	char namebuf[KSYM_NAME_LEN+1];
-	unsigned long size, offset;
 	const char *sym_name;
-	char *modname;
  
-	sym_name = kallsyms_lookup(addr, &size, &offset, &modname, namebuf);
+	sym_name = kallsyms_lookup(addr, NULL, NULL, NULL, namebuf);
 	if (sym_name)
 		SEQ_printf(m, "%s", sym_name);
 	else
@@ -258,11 +258,9 @@
 static void print_name_offset(struct seq_file *m, unsigned long addr)
 {
 	char namebuf[KSYM_NAME_LEN+1];
-	unsigned long size, offset;
 	const char *sym_name;
-	char *modname;
  
-	sym_name = kallsyms_lookup(addr, &size, &offset, &modname, namebuf);
+	sym_name = kallsyms_lookup(addr, NULL, NULL, NULL, namebuf);
 	if (sym_name)
 		seq_printf(m, "%s", sym_name);
 	else
...	...	@@ -216,11 +216,8 @@
216	216	/* Handle some frequent special cases.... */
217	217	{
218	218	char symname[KSYM_NAME_LEN+1];
219		- char *modname;
220		- unsigned long symsize, offset;
221	219
222		- kallsyms_lookup(info->ip, &symsize, &offset,
223		- &modname, symname);
	220	+ kallsyms_lookup(info->ip, NULL, NULL, NULL, symname);
224	221
225	222	dbg("info->ip = 0x%lx, name = %s\n", info->ip, symname);
226	223
...	...	@@ -1217,7 +1217,6 @@
1217	1217	{
1218	1218	unsigned long size, offset;
1219	1219	const char *name;
1220		- char *modname;
1221	1220
1222	1221	startp = endp = 0;
1223	1222	if (pc == 0)
...	...	@@ -1225,7 +1224,7 @@
1225	1224	if (setjmp(bus_error_jmp) == 0) {
1226	1225	catch_memory_errors = 1;
1227	1226	sync();
1228		- name = kallsyms_lookup(pc, &size, &offset, &modname, tmpstr);
	1227	+ name = kallsyms_lookup(pc, &size, &offset, NULL, tmpstr);
1229	1228	if (name != NULL) {
1230	1229	*startp = pc - offset;
1231	1230	*endp = pc - offset + size;
...	...	@@ -46,15 +46,15 @@
46	46	struct pt_regs *regs)
47	47	{
48	48	const char *sym;
49		- char *modname, namebuf[128];
50		- unsigned long offset, size;
	49	+ char namebuf[128];
	50	+ unsigned long offset;
51	51	unsigned long prologue = 0;
52	52	unsigned long fp_displacement = 0;
53	53	unsigned long fp_prev = 0;
54	54	unsigned long offset_r14 = 0, offset_r18 = 0;
55	55	int i, found_prologue_end = 0;
56	56
57		- sym = kallsyms_lookup(pc, &size, &offset, &modname, namebuf);
	57	+ sym = kallsyms_lookup(pc, NULL, &offset, NULL, namebuf);
58	58	if (!sym)
59	59	return -EINVAL;
60	60
...	...	@@ -278,14 +278,13 @@
278	278	*/
279	279	static int proc_pid_wchan(struct task_struct task, char buffer)
280	280	{
281		- char *modname;
282	281	const char *sym_name;
283		- unsigned long wchan, size, offset;
	282	+ unsigned long wchan;
284	283	char namebuf[KSYM_NAME_LEN+1];
285	284
286	285	wchan = get_wchan(task);
287	286
288		- sym_name = kallsyms_lookup(wchan, &size, &offset, &modname, namebuf);
	287	+ sym_name = kallsyms_lookup(wchan, NULL, NULL, NULL, namebuf);
289	288	if (sym_name)
290	289	return sprintf(buffer, "%s", sym_name);
291	290	return sprintf(buffer, "%lu", wchan);
...	...	@@ -214,8 +214,10 @@
214	214	symbol_end = (unsigned long)_etext;
215	215	}
216	216
217		- *symbolsize = symbol_end - symbol_start;
218		- *offset = addr - symbol_start;
	217	+ if (symbolsize)
	218	+ *symbolsize = symbol_end - symbol_start;
	219	+ if (offset)
	220	+ *offset = addr - symbol_start;
219	221
220	222	return low;
221	223	}
...	...	@@ -868,13 +868,13 @@
868	868	struct kprobe p, kp;
869	869	const char *sym = NULL;
870	870	unsigned int i = (loff_t ) v;
871		- unsigned long size, offset = 0;
	871	+ unsigned long offset = 0;
872	872	char *modname, namebuf[128];
873	873
874	874	head = &kprobe_table[i];
875	875	preempt_disable();
876	876	hlist_for_each_entry_rcu(p, node, head, hlist) {
877		- sym = kallsyms_lookup((unsigned long)p->addr, &size,
	877	+ sym = kallsyms_lookup((unsigned long)p->addr, NULL,
878	878	&offset, &modname, namebuf);
879	879	if (p->pre_handler == aggr_pre_handler) {
880	880	list_for_each_entry_rcu(kp, &p->list, list)
...	...	@@ -340,10 +340,7 @@
340	340
341	341	const char * __get_key_name(struct lockdep_subclass_key key, char str)
342	342	{
343		- unsigned long offs, size;
344		- char *modname;
345		-
346		- return kallsyms_lookup((unsigned long)key, &size, &offs, &modname, str);
	343	+ return kallsyms_lookup((unsigned long)key, NULL, NULL, NULL, str);
347	344	}
348	345
349	346	void
...	...	@@ -2098,8 +2098,10 @@
2098	2098	if (!best)
2099	2099	return NULL;
2100	2100
2101		- *size = nextval - mod->symtab[best].st_value;
2102		- *offset = addr - mod->symtab[best].st_value;
	2101	+ if (size)
	2102	+ *size = nextval - mod->symtab[best].st_value;
	2103	+ if (offset)
	2104	+ *offset = addr - mod->symtab[best].st_value;
2103	2105	return mod->strtab + mod->symtab[best].st_name;
2104	2106	}
2105	2107
...	...	@@ -40,11 +40,9 @@
40	40	{
41	41	unsigned long addr = (unsigned long)sym;
42	42	char namebuf[KSYM_NAME_LEN+1];
43		- unsigned long size, offset;
44	43	const char *sym_name;
45		- char *modname;
46	44
47		- sym_name = kallsyms_lookup(addr, &size, &offset, &modname, namebuf);
	45	+ sym_name = kallsyms_lookup(addr, NULL, NULL, NULL, namebuf);
48	46	if (sym_name)
49	47	SEQ_printf(m, "%s", sym_name);
50	48	else
...	...	@@ -258,11 +258,9 @@
258	258	static void print_name_offset(struct seq_file *m, unsigned long addr)
259	259	{
260	260	char namebuf[KSYM_NAME_LEN+1];
261		- unsigned long size, offset;
262	261	const char *sym_name;
263		- char *modname;
264	262
265		- sym_name = kallsyms_lookup(addr, &size, &offset, &modname, namebuf);
	263	+ sym_name = kallsyms_lookup(addr, NULL, NULL, NULL, namebuf);
266	264	if (sym_name)
267	265	seq_printf(m, "%s", sym_name);
268	266	else