[PATCH V4 1/3] kallsyms: Simplify update_iter_mod()

[Adrian Hunter]

The logic in update_iter_mod() is overcomplicated and gets worse every time
another get_ksymbol_* function is added.

In preparation for adding another get_ksymbol_* function, simplify logic in
update_iter_mod().

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Acked-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
---
 kernel/kallsyms.c | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index a23e21ada81b..aa31aa07f2ef 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -506,27 +506,24 @@ static void reset_iter(struct kallsym_iter *iter, loff_t new_pos)
 	}
 }
 
+/*
+ * The end position (last + 1) of each additional kallsyms section is recorded
+ * in iter->pos_..._end as each section is added, and so can be used to
+ * determine which get_ksymbol_...() function to call next.
+ */
 static int update_iter_mod(struct kallsym_iter *iter, loff_t pos)
 {
 	iter->pos = pos;
 
-	if (iter->pos_ftrace_mod_end > 0 &&
-	    iter->pos_ftrace_mod_end < iter->pos)
-		return get_ksymbol_bpf(iter);
-
-	if (iter->pos_mod_end > 0 &&
-	    iter->pos_mod_end < iter->pos) {
-		if (!get_ksymbol_ftrace_mod(iter))
-			return get_ksymbol_bpf(iter);
+	if ((!iter->pos_mod_end || iter->pos_mod_end > pos) &&
+	    get_ksymbol_mod(iter))
 		return 1;
-	}
 
-	if (!get_ksymbol_mod(iter)) {
-		if (!get_ksymbol_ftrace_mod(iter))
-			return get_ksymbol_bpf(iter);
-	}
+	if ((!iter->pos_ftrace_mod_end || iter->pos_ftrace_mod_end > pos) &&
+	    get_ksymbol_ftrace_mod(iter))
+		return 1;
 
-	return 1;
+	return get_ksymbol_bpf(iter);
 }
 
 /* Returns false if pos at or past end of file. */
-- 
1.9.1