[PATCH v2] riscv: module: use a plain variable for list_head instead of a pointer

From: Clément Léger
Date: Wed Nov 27 2024 - 09:25:40 EST


rel_head's list_head member, rel_entry, doesn't need to be allocated,
its storage can just be part of the allocated rel_head. Remove the
pointer which allows to get rid of the allocation as well as an existing
memory leak found by Kai Zang using kmemleak.

Reported-by: Kai Zhang <zhangkai@xxxxxxxxxxx>
Signed-off-by: Clément Léger <cleger@xxxxxxxxxxxx>
Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
---

V2:
- Add Kai Reported-by
- Reword the commit description (Andrew)

---
arch/riscv/kernel/module.c | 18 ++++--------------
1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
index 1cd461f3d872..47d0ebeec93c 100644
--- a/arch/riscv/kernel/module.c
+++ b/arch/riscv/kernel/module.c
@@ -23,7 +23,7 @@ struct used_bucket {

struct relocation_head {
struct hlist_node node;
- struct list_head *rel_entry;
+ struct list_head rel_entry;
void *location;
};

@@ -634,7 +634,7 @@ process_accumulated_relocations(struct module *me,
location = rel_head_iter->location;
list_for_each_entry_safe(rel_entry_iter,
rel_entry_iter_tmp,
- rel_head_iter->rel_entry,
+ &rel_head_iter->rel_entry,
head) {
curr_type = rel_entry_iter->type;
reloc_handlers[curr_type].reloc_handler(
@@ -704,16 +704,7 @@ static int add_relocation_to_accumulate(struct module *me, int type,
return -ENOMEM;
}

- rel_head->rel_entry =
- kmalloc(sizeof(struct list_head), GFP_KERNEL);
-
- if (!rel_head->rel_entry) {
- kfree(entry);
- kfree(rel_head);
- return -ENOMEM;
- }
-
- INIT_LIST_HEAD(rel_head->rel_entry);
+ INIT_LIST_HEAD(&rel_head->rel_entry);
rel_head->location = location;
INIT_HLIST_NODE(&rel_head->node);
if (!current_head->first) {
@@ -722,7 +713,6 @@ static int add_relocation_to_accumulate(struct module *me, int type,

if (!bucket) {
kfree(entry);
- kfree(rel_head->rel_entry);
kfree(rel_head);
return -ENOMEM;
}
@@ -735,7 +725,7 @@ static int add_relocation_to_accumulate(struct module *me, int type,
}

/* Add relocation to head of discovered rel_head */
- list_add_tail(&entry->head, rel_head->rel_entry);
+ list_add_tail(&entry->head, &rel_head->rel_entry);

return 0;
}
--
2.45.2