[PATCH] riscv: module: use a plain variable for list_head instead of a pointer
Clément Léger
cleger at rivosinc.com
Wed Nov 27 06:18:25 PST 2024
On 27/11/2024 15:02, Andrew Jones wrote:
> On Wed, Nov 27, 2024 at 11:30:14AM +0100, Clément Léger wrote:
>> list_head does not need to be allocated, it can be a plain variable.
>
> 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.
>
> It'd be nice to add how the memory leak was found. Inspection or some
> tool?
Yeah sure, it was actually found by Kai Zang, I have added him as Cc but
I can surely give him credit for finding the memleak, I'll add him with
a Reported-by.
Thanks,
Clément
>
>>
>> Signed-off-by: Clément Léger <cleger at rivosinc.com>
>>
>> ---
>> 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
>>
>>
>
> Other than the commit message change suggestions,
>
> Reviewed-by: Andrew Jones <ajones at ventanamicro.com>
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