2023-07-25 12:06:28

by Jinjie Ruan

Subject: [PATCH -next] kernel: kprobes: Use struct_size()

Use struct_size() instead of hand-writing it, when allocating a structure
with a flex array.

This is less verbose.

Signed-off-by: Ruan Jinjie <[email protected]>
---
kernel/kprobes.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 1fc6095d502d..1d749a917b59 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -2220,8 +2220,7 @@ int register_kretprobe(struct kretprobe *rp)
return -ENOMEM;

for (i = 0; i < rp->maxactive; i++) {
- inst = kzalloc(sizeof(struct kretprobe_instance) +
- rp->data_size, GFP_KERNEL);
+ inst = kzalloc(struct_size(inst, data, rp->data_size), GFP_KERNEL);
if (inst == NULL) {
rethook_free(rp->rh);
rp->rh = NULL;
@@ -2244,8 +2243,7 @@ int register_kretprobe(struct kretprobe *rp)

rp->rph->rp = rp;
for (i = 0; i < rp->maxactive; i++) {
- inst = kzalloc(sizeof(struct kretprobe_instance) +
- rp->data_size, GFP_KERNEL);
+ inst = kzalloc(struct_size(inst, data, rp->data_size), GFP_KERNEL);
if (inst == NULL) {
refcount_set(&rp->rph->ref, i);
free_rp_inst(rp);
--
2.34.1

2023-07-25 13:22:28

by Masami Hiramatsu

Subject: Re: [PATCH -next] kernel: kprobes: Use struct_size()

On Tue, 25 Jul 2023 19:54:24 +0000
Ruan Jinjie <[email protected]> wrote:

> Use struct_size() instead of hand-writing it, when allocating a structure
> with a flex array.
>
> This is less verbose.
>

Looks goo to me.

Acked-by: Masami Hiramatsu (Google) <[email protected]>

Thanks!

> Signed-off-by: Ruan Jinjie <[email protected]>
> ---
> kernel/kprobes.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index 1fc6095d502d..1d749a917b59 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -2220,8 +2220,7 @@ int register_kretprobe(struct kretprobe *rp)
> return -ENOMEM;
>
> for (i = 0; i < rp->maxactive; i++) {
> - inst = kzalloc(sizeof(struct kretprobe_instance) +
> - rp->data_size, GFP_KERNEL);
> + inst = kzalloc(struct_size(inst, data, rp->data_size), GFP_KERNEL);
> if (inst == NULL) {
> rethook_free(rp->rh);
> rp->rh = NULL;
> @@ -2244,8 +2243,7 @@ int register_kretprobe(struct kretprobe *rp)
>
> rp->rph->rp = rp;
> for (i = 0; i < rp->maxactive; i++) {
> - inst = kzalloc(sizeof(struct kretprobe_instance) +
> - rp->data_size, GFP_KERNEL);
> + inst = kzalloc(struct_size(inst, data, rp->data_size), GFP_KERNEL);
> if (inst == NULL) {
> refcount_set(&rp->rph->ref, i);
> free_rp_inst(rp);
> --
> 2.34.1
>


--
Masami Hiramatsu (Google) <[email protected]>