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

From: Adrian Hunter
Date: Wed Jun 06 2018 - 08:55:47 EST


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