[PATCH 1/4] module: Split the find_symbol_in_section function

[Alessio Igor Bogani <abogani@kernel.org>]

Split the find_symbol_in_section() in two: the first one
(that is compare_symbol_in_section()) for compare values during the search and
the second one (that is found_symbol_in_section()) executed when values will be
found. Rename each_symbol() in search_symbol() to let its' users notice
the change.

This work was supported by a hardware donation from the CE Linux Forum.

Signed-off-by: Alessio Igor Bogani <abogani@kernel.org>
---
 include/linux/module.h |    3 ++-
 kernel/module.c        |   29 ++++++++++++++++++-----------
 2 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/include/linux/module.h b/include/linux/module.h
index 5de4204..b62f0a2 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -475,7 +475,8 @@ const struct kernel_symbol *find_symbol(const char *name,
 					bool warn);
 
 /* Walk the exported symbol table */
-bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
+bool search_symbol(int (*cmp) (const void *va, const void *vb),
+				bool (*fn)(const struct symsearch *arr, struct module *owner,
 			    unsigned int symnum, void *data), void *data);
 
 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
diff --git a/kernel/module.c b/kernel/module.c
index d5938a5..8845a0b 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -238,6 +238,7 @@ extern const unsigned long __start___kcrctab_unused_gpl[];
 static bool each_symbol_in_section(const struct symsearch *arr,
 				   unsigned int arrsize,
 				   struct module *owner,
+				   int (*cmp) (const void *va, const void *vb),
 				   bool (*fn)(const struct symsearch *syms,
 					      struct module *owner,
 					      unsigned int symnum, void *data),
@@ -247,15 +248,16 @@ static bool each_symbol_in_section(const struct symsearch *arr,
 
 	for (j = 0; j < arrsize; j++) {
 		for (i = 0; i < arr[j].stop - arr[j].start; i++)
-			if (fn(&arr[j], owner, i, data))
-				return true;
+			if (cmp(data, &arr[j].start[i]) == 0)
+				return fn(&arr[j], owner, i, data);
 	}
 
 	return false;
 }
 
 /* Returns true as soon as fn returns true, otherwise false. */
-bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
+bool search_symbol(int (*cmp) (const void *va, const void *data),
+				bool (*fn)(const struct symsearch *arr, struct module *owner,
 			    unsigned int symnum, void *data), void *data)
 {
 	struct module *mod;
@@ -278,7 +280,7 @@ bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
 #endif
 	};
 
-	if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
+	if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, cmp, fn, data))
 		return true;
 
 	list_for_each_entry_rcu(mod, &modules, list) {
@@ -304,12 +306,12 @@ bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
 #endif
 		};
 
-		if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
+		if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, cmp, fn, data))
 			return true;
 	}
 	return false;
 }
-EXPORT_SYMBOL_GPL(each_symbol);
+EXPORT_SYMBOL_GPL(search_symbol);
 
 struct find_symbol_arg {
 	/* Input */
@@ -323,15 +325,20 @@ struct find_symbol_arg {
 	const struct kernel_symbol *sym;
 };
 
-static bool find_symbol_in_section(const struct symsearch *syms,
+static int compare_symbol_in_section(const void *va, const void *vb)
+{
+	const struct find_symbol_arg *a;
+	const struct kernel_symbol *b;
+	a = va; b = vb;
+	return strcmp(a->name, b->name);
+}
+
+static bool found_symbol_in_section(const struct symsearch *syms,
 				   struct module *owner,
 				   unsigned int symnum, void *data)
 {
 	struct find_symbol_arg *fsa = data;
 
-	if (strcmp(syms->start[symnum].name, fsa->name) != 0)
-		return false;
-
 	if (!fsa->gplok) {
 		if (syms->licence == GPL_ONLY)
 			return false;
@@ -379,7 +386,7 @@ const struct kernel_symbol *find_symbol(const char *name,
 	fsa.gplok = gplok;
 	fsa.warn = warn;
 
-	if (each_symbol(find_symbol_in_section, &fsa)) {
+	if (search_symbol(compare_symbol_in_section, found_symbol_in_section, &fsa)) {
 		if (owner)
 			*owner = fsa.owner;
 		if (crc)
-- 
1.7.0.4