This Patch adds kfuncs bpf_iter_css_{pre,post}_{new,next,destroy} which
allow creation and manipulation of struct bpf_iter_css in open-coded
iterator style. These kfuncs actually wrapps css_next_descendant_{pre,
post}. BPF programs can use these kfuncs through bpf_for_each macro for
iteration of all descendant css under a root css.
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
---
include/uapi/linux/bpf.h | 8 +++++
kernel/bpf/helpers.c | 6 ++++
kernel/bpf/task_iter.c | 53 ++++++++++++++++++++++++++++++++++
tools/include/uapi/linux/bpf.h | 8 +++++
tools/lib/bpf/bpf_helpers.h | 12 ++++++++
5 files changed, 87 insertions(+)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index befa55b52e29..57760afc13d0 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -7326,4 +7326,12 @@ struct bpf_iter_process {
__u64 __opaque[1];
} __attribute__((aligned(8)));
+struct bpf_iter_css_pre {
+ __u64 __opaque[2];
+} __attribute__((aligned(8)));
+
+struct bpf_iter_css_post {
+ __u64 __opaque[2];
+} __attribute__((aligned(8)));
+
#endif /* _UAPI__LINUX_BPF_H__ */
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 9b7d2c6f99d1..ca1f6404af9e 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -2510,6 +2510,12 @@ BTF_ID_FLAGS(func, bpf_iter_css_task_destroy, KF_ITER_DESTROY)
BTF_ID_FLAGS(func, bpf_iter_process_new, KF_ITER_NEW)
BTF_ID_FLAGS(func, bpf_iter_process_next, KF_ITER_NEXT | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_iter_process_destroy, KF_ITER_DESTROY)
+BTF_ID_FLAGS(func, bpf_iter_css_pre_new, KF_ITER_NEW)
+BTF_ID_FLAGS(func, bpf_iter_css_pre_next, KF_ITER_NEXT | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_iter_css_pre_destroy, KF_ITER_DESTROY)
+BTF_ID_FLAGS(func, bpf_iter_css_post_new, KF_ITER_NEW)
+BTF_ID_FLAGS(func, bpf_iter_css_post_next, KF_ITER_NEXT | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_iter_css_post_destroy, KF_ITER_DESTROY)
BTF_ID_FLAGS(func, bpf_dynptr_adjust)
BTF_ID_FLAGS(func, bpf_dynptr_is_null)
BTF_ID_FLAGS(func, bpf_dynptr_is_rdonly)
diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c
index 9d1927dc3a06..8963fc779b87 100644
--- a/kernel/bpf/task_iter.c
+++ b/kernel/bpf/task_iter.c
@@ -880,6 +880,59 @@ __bpf_kfunc void bpf_iter_process_destroy(struct bpf_iter_process *it)
{
}
+struct bpf_iter_css_kern {
+ struct cgroup_subsys_state *root;
+ struct cgroup_subsys_state *pos;
+} __attribute__((aligned(8)));
+
+__bpf_kfunc int bpf_iter_css_pre_new(struct bpf_iter_css_pre *it,
+ struct cgroup_subsys_state *root)
+{
+ struct bpf_iter_css_kern *kit = (void *)it;
+
+ BUILD_BUG_ON(sizeof(struct bpf_iter_css_kern) != sizeof(struct bpf_iter_css_pre));
+ BUILD_BUG_ON(__alignof__(struct bpf_iter_css_kern) != __alignof__(struct bpf_iter_css_pre));
+ kit->root = root;
+ kit->pos = NULL;
+ return 0;
+}
+
+__bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_pre_next(struct bpf_iter_css_pre *it)
+{
+ struct bpf_iter_css_kern *kit = (void *)it;
+
+ kit->pos = css_next_descendant_pre(kit->pos, kit->root);
+ return kit->pos;
+}
+
+__bpf_kfunc void bpf_iter_css_pre_destroy(struct bpf_iter_css_pre *it)
+{
+}
+
+__bpf_kfunc int bpf_iter_css_post_new(struct bpf_iter_css_post *it,
+ struct cgroup_subsys_state *root)
+{
+ struct bpf_iter_css_kern *kit = (void *)it;
+
+ BUILD_BUG_ON(sizeof(struct bpf_iter_css_kern) != sizeof(struct bpf_iter_css_post));
+ BUILD_BUG_ON(__alignof__(struct bpf_iter_css_kern) != __alignof__(struct bpf_iter_css_post));
+ kit->root = root;
+ kit->pos = NULL;
+ return 0;
+}
+
+__bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_post_next(struct bpf_iter_css_post *it)
+{
+ struct bpf_iter_css_kern *kit = (void *)it;
+
+ kit->pos = css_next_descendant_post(kit->pos, kit->root);
+ return kit->pos;
+}
+
+__bpf_kfunc void bpf_iter_css_post_destroy(struct bpf_iter_css_post *it)
+{
+}
+
DEFINE_PER_CPU(struct mmap_unlock_irq_work, mmap_unlock_work);
static void do_mmap_read_unlock(struct irq_work *entry)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index befa55b52e29..57760afc13d0 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -7326,4 +7326,12 @@ struct bpf_iter_process {
__u64 __opaque[1];
} __attribute__((aligned(8)));
+struct bpf_iter_css_pre {
+ __u64 __opaque[2];
+} __attribute__((aligned(8)));
+
+struct bpf_iter_css_post {
+ __u64 __opaque[2];
+} __attribute__((aligned(8)));
+
#endif /* _UAPI__LINUX_BPF_H__ */
diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index 858252c2641c..6e5bd9ef14d6 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -315,6 +315,18 @@ extern int bpf_iter_process_new(struct bpf_iter_process *it) __weak __ksym;
extern struct task_struct *bpf_iter_process_next(struct bpf_iter_process *it) __weak __ksym;
extern void bpf_iter_process_destroy(struct bpf_iter_process *it) __weak __ksym;
+struct bpf_iter_css_pre;
+extern int bpf_iter_css_pre_new(struct bpf_iter_css_pre *it,
+ struct cgroup_subsys_state *root) __weak __ksym;
+extern struct cgroup_subsys_state *bpf_iter_css_pre_next(struct bpf_iter_css_pre *it) __weak __ksym;
+extern void bpf_iter_css_pre_destroy(struct bpf_iter_css_pre *it) __weak __ksym;
+
+struct bpf_iter_css_post;
+extern int bpf_iter_css_post_new(struct bpf_iter_css_post *it,
+ struct cgroup_subsys_state *root) __weak __ksym;
+extern struct cgroup_subsys_state *bpf_iter_css_post_next(struct bpf_iter_css_post *it) __weak __ksym;
+extern void bpf_iter_css_post_destroy(struct bpf_iter_css_post *it) __weak __ksym;
+
#ifndef bpf_for_each
/* bpf_for_each(iter_type, cur_elem, args...) provides generic construct for
* using BPF open-coded iterators without having to write mundane explicit
--
2.20.1On Tue, Sep 12, 2023 at 12:02 AM Chuyi Zhou <zhouchuyi@bytedance.com> wrote:
>
> This Patch adds kfuncs bpf_iter_css_{pre,post}_{new,next,destroy} which
> allow creation and manipulation of struct bpf_iter_css in open-coded
> iterator style. These kfuncs actually wrapps css_next_descendant_{pre,
> post}. BPF programs can use these kfuncs through bpf_for_each macro for
> iteration of all descendant css under a root css.
>
> Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
> ---
> include/uapi/linux/bpf.h | 8 +++++
> kernel/bpf/helpers.c | 6 ++++
> kernel/bpf/task_iter.c | 53 ++++++++++++++++++++++++++++++++++
> tools/include/uapi/linux/bpf.h | 8 +++++
> tools/lib/bpf/bpf_helpers.h | 12 ++++++++
> 5 files changed, 87 insertions(+)
>
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index befa55b52e29..57760afc13d0 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -7326,4 +7326,12 @@ struct bpf_iter_process {
> __u64 __opaque[1];
> } __attribute__((aligned(8)));
>
> +struct bpf_iter_css_pre {
> + __u64 __opaque[2];
> +} __attribute__((aligned(8)));
> +
> +struct bpf_iter_css_post {
> + __u64 __opaque[2];
> +} __attribute__((aligned(8)));
> +
> #endif /* _UAPI__LINUX_BPF_H__ */
> diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
> index 9b7d2c6f99d1..ca1f6404af9e 100644
> --- a/kernel/bpf/helpers.c
> +++ b/kernel/bpf/helpers.c
> @@ -2510,6 +2510,12 @@ BTF_ID_FLAGS(func, bpf_iter_css_task_destroy, KF_ITER_DESTROY)
> BTF_ID_FLAGS(func, bpf_iter_process_new, KF_ITER_NEW)
> BTF_ID_FLAGS(func, bpf_iter_process_next, KF_ITER_NEXT | KF_RET_NULL)
> BTF_ID_FLAGS(func, bpf_iter_process_destroy, KF_ITER_DESTROY)
> +BTF_ID_FLAGS(func, bpf_iter_css_pre_new, KF_ITER_NEW)
> +BTF_ID_FLAGS(func, bpf_iter_css_pre_next, KF_ITER_NEXT | KF_RET_NULL)
> +BTF_ID_FLAGS(func, bpf_iter_css_pre_destroy, KF_ITER_DESTROY)
> +BTF_ID_FLAGS(func, bpf_iter_css_post_new, KF_ITER_NEW)
> +BTF_ID_FLAGS(func, bpf_iter_css_post_next, KF_ITER_NEXT | KF_RET_NULL)
> +BTF_ID_FLAGS(func, bpf_iter_css_post_destroy, KF_ITER_DESTROY)
> BTF_ID_FLAGS(func, bpf_dynptr_adjust)
> BTF_ID_FLAGS(func, bpf_dynptr_is_null)
> BTF_ID_FLAGS(func, bpf_dynptr_is_rdonly)
> diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c
> index 9d1927dc3a06..8963fc779b87 100644
> --- a/kernel/bpf/task_iter.c
> +++ b/kernel/bpf/task_iter.c
> @@ -880,6 +880,59 @@ __bpf_kfunc void bpf_iter_process_destroy(struct bpf_iter_process *it)
> {
> }
>
> +struct bpf_iter_css_kern {
> + struct cgroup_subsys_state *root;
> + struct cgroup_subsys_state *pos;
> +} __attribute__((aligned(8)));
> +
> +__bpf_kfunc int bpf_iter_css_pre_new(struct bpf_iter_css_pre *it,
> + struct cgroup_subsys_state *root)
similar to my comment on previous patches, please see
kernel/bpf/cgroup_iter.c for iter/cgroup iterator program. Let's stay
consistent. We have one iterator that accepts parameters defining
iteration order and starting cgroup. Unless there are some technical
reasons we can't follow similar approach with this open-coded iter,
let's use the same approach. We can even reuse
BPF_CGROUP_ITER_DESCENDANTS_PRE, BPF_CGROUP_ITER_DESCENDANTS_POST,
BPF_CGROUP_ITER_ANCESTORS_UP enums.
> +{
> + struct bpf_iter_css_kern *kit = (void *)it;
> +
> + BUILD_BUG_ON(sizeof(struct bpf_iter_css_kern) != sizeof(struct bpf_iter_css_pre));
> + BUILD_BUG_ON(__alignof__(struct bpf_iter_css_kern) != __alignof__(struct bpf_iter_css_pre));
> + kit->root = root;
> + kit->pos = NULL;
> + return 0;
> +}
> +
> +__bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_pre_next(struct bpf_iter_css_pre *it)
> +{
> + struct bpf_iter_css_kern *kit = (void *)it;
> +
> + kit->pos = css_next_descendant_pre(kit->pos, kit->root);
> + return kit->pos;
> +}
> +
> +__bpf_kfunc void bpf_iter_css_pre_destroy(struct bpf_iter_css_pre *it)
> +{
> +}
> +
> +__bpf_kfunc int bpf_iter_css_post_new(struct bpf_iter_css_post *it,
> + struct cgroup_subsys_state *root)
> +{
> + struct bpf_iter_css_kern *kit = (void *)it;
> +
> + BUILD_BUG_ON(sizeof(struct bpf_iter_css_kern) != sizeof(struct bpf_iter_css_post));
> + BUILD_BUG_ON(__alignof__(struct bpf_iter_css_kern) != __alignof__(struct bpf_iter_css_post));
> + kit->root = root;
> + kit->pos = NULL;
> + return 0;
> +}
> +
> +__bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_post_next(struct bpf_iter_css_post *it)
> +{
> + struct bpf_iter_css_kern *kit = (void *)it;
> +
> + kit->pos = css_next_descendant_post(kit->pos, kit->root);
> + return kit->pos;
> +}
> +
> +__bpf_kfunc void bpf_iter_css_post_destroy(struct bpf_iter_css_post *it)
> +{
> +}
> +
> DEFINE_PER_CPU(struct mmap_unlock_irq_work, mmap_unlock_work);
>
> static void do_mmap_read_unlock(struct irq_work *entry)
> diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
> index befa55b52e29..57760afc13d0 100644
> --- a/tools/include/uapi/linux/bpf.h
> +++ b/tools/include/uapi/linux/bpf.h
> @@ -7326,4 +7326,12 @@ struct bpf_iter_process {
> __u64 __opaque[1];
> } __attribute__((aligned(8)));
>
> +struct bpf_iter_css_pre {
> + __u64 __opaque[2];
> +} __attribute__((aligned(8)));
> +
> +struct bpf_iter_css_post {
> + __u64 __opaque[2];
> +} __attribute__((aligned(8)));
> +
> #endif /* _UAPI__LINUX_BPF_H__ */
> diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
> index 858252c2641c..6e5bd9ef14d6 100644
> --- a/tools/lib/bpf/bpf_helpers.h
> +++ b/tools/lib/bpf/bpf_helpers.h
> @@ -315,6 +315,18 @@ extern int bpf_iter_process_new(struct bpf_iter_process *it) __weak __ksym;
> extern struct task_struct *bpf_iter_process_next(struct bpf_iter_process *it) __weak __ksym;
> extern void bpf_iter_process_destroy(struct bpf_iter_process *it) __weak __ksym;
>
> +struct bpf_iter_css_pre;
> +extern int bpf_iter_css_pre_new(struct bpf_iter_css_pre *it,
> + struct cgroup_subsys_state *root) __weak __ksym;
> +extern struct cgroup_subsys_state *bpf_iter_css_pre_next(struct bpf_iter_css_pre *it) __weak __ksym;
> +extern void bpf_iter_css_pre_destroy(struct bpf_iter_css_pre *it) __weak __ksym;
> +
> +struct bpf_iter_css_post;
> +extern int bpf_iter_css_post_new(struct bpf_iter_css_post *it,
> + struct cgroup_subsys_state *root) __weak __ksym;
> +extern struct cgroup_subsys_state *bpf_iter_css_post_next(struct bpf_iter_css_post *it) __weak __ksym;
> +extern void bpf_iter_css_post_destroy(struct bpf_iter_css_post *it) __weak __ksym;
> +
> #ifndef bpf_for_each
> /* bpf_for_each(iter_type, cur_elem, args...) provides generic construct for
> * using BPF open-coded iterators without having to write mundane explicit
> --
> 2.20.1
>
Hello.
在 2023/9/15 07:26, Andrii Nakryiko 写道:
> On Tue, Sep 12, 2023 at 12:02 AM Chuyi Zhou <zhouchuyi@bytedance.com> wrote:
>>
>> This Patch adds kfuncs bpf_iter_css_{pre,post}_{new,next,destroy} which
>> allow creation and manipulation of struct bpf_iter_css in open-coded
>> iterator style. These kfuncs actually wrapps css_next_descendant_{pre,
>> post}. BPF programs can use these kfuncs through bpf_for_each macro for
>> iteration of all descendant css under a root css.
>>
>> Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
>> ---
>> include/uapi/linux/bpf.h | 8 +++++
>> kernel/bpf/helpers.c | 6 ++++
>> kernel/bpf/task_iter.c | 53 ++++++++++++++++++++++++++++++++++
>> tools/include/uapi/linux/bpf.h | 8 +++++
>> tools/lib/bpf/bpf_helpers.h | 12 ++++++++
>> 5 files changed, 87 insertions(+)
>>
>> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
>> index befa55b52e29..57760afc13d0 100644
>> --- a/include/uapi/linux/bpf.h
>> +++ b/include/uapi/linux/bpf.h
>> @@ -7326,4 +7326,12 @@ struct bpf_iter_process {
>> __u64 __opaque[1];
>> } __attribute__((aligned(8)));
>>
>> +struct bpf_iter_css_pre {
>> + __u64 __opaque[2];
>> +} __attribute__((aligned(8)));
>> +
>> +struct bpf_iter_css_post {
>> + __u64 __opaque[2];
>> +} __attribute__((aligned(8)));
>> +
>> #endif /* _UAPI__LINUX_BPF_H__ */
>> diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
>> index 9b7d2c6f99d1..ca1f6404af9e 100644
>> --- a/kernel/bpf/helpers.c
>> +++ b/kernel/bpf/helpers.c
>> @@ -2510,6 +2510,12 @@ BTF_ID_FLAGS(func, bpf_iter_css_task_destroy, KF_ITER_DESTROY)
>> BTF_ID_FLAGS(func, bpf_iter_process_new, KF_ITER_NEW)
>> BTF_ID_FLAGS(func, bpf_iter_process_next, KF_ITER_NEXT | KF_RET_NULL)
>> BTF_ID_FLAGS(func, bpf_iter_process_destroy, KF_ITER_DESTROY)
>> +BTF_ID_FLAGS(func, bpf_iter_css_pre_new, KF_ITER_NEW)
>> +BTF_ID_FLAGS(func, bpf_iter_css_pre_next, KF_ITER_NEXT | KF_RET_NULL)
>> +BTF_ID_FLAGS(func, bpf_iter_css_pre_destroy, KF_ITER_DESTROY)
>> +BTF_ID_FLAGS(func, bpf_iter_css_post_new, KF_ITER_NEW)
>> +BTF_ID_FLAGS(func, bpf_iter_css_post_next, KF_ITER_NEXT | KF_RET_NULL)
>> +BTF_ID_FLAGS(func, bpf_iter_css_post_destroy, KF_ITER_DESTROY)
>> BTF_ID_FLAGS(func, bpf_dynptr_adjust)
>> BTF_ID_FLAGS(func, bpf_dynptr_is_null)
>> BTF_ID_FLAGS(func, bpf_dynptr_is_rdonly)
>> diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c
>> index 9d1927dc3a06..8963fc779b87 100644
>> --- a/kernel/bpf/task_iter.c
>> +++ b/kernel/bpf/task_iter.c
>> @@ -880,6 +880,59 @@ __bpf_kfunc void bpf_iter_process_destroy(struct bpf_iter_process *it)
>> {
>> }
>>
>> +struct bpf_iter_css_kern {
>> + struct cgroup_subsys_state *root;
>> + struct cgroup_subsys_state *pos;
>> +} __attribute__((aligned(8)));
>> +
>> +__bpf_kfunc int bpf_iter_css_pre_new(struct bpf_iter_css_pre *it,
>> + struct cgroup_subsys_state *root)
>
> similar to my comment on previous patches, please see
> kernel/bpf/cgroup_iter.c for iter/cgroup iterator program. Let's stay
> consistent. We have one iterator that accepts parameters defining
> iteration order and starting cgroup. Unless there are some technical
> reasons we can't follow similar approach with this open-coded iter,
> let's use the same approach. We can even reuse
> BPF_CGROUP_ITER_DESCENDANTS_PRE, BPF_CGROUP_ITER_DESCENDANTS_POST,
> BPF_CGROUP_ITER_ANCESTORS_UP enums.
>
I know your concern. It would be nice if we keep consistent with
kernel/bpf/cgroup_iter.c
But this patch actually want to support iterating css
(cgroup_subsys_state) not cgroup (css is more low lever).
With css_iter we can do something like
"for_each_mem_cgroup_tree/cpuset_for_each_descendant_pre"
in BPF Progs which is hard for cgroup_iter. In the future we can use
this iterator to plug some customizable policy in other resource control
system.
BTW, what I did in RFC actually very similar with the approach of
cgroup_iter.
(https://lore.kernel.org/all/20230827072057.1591929-4-zhouchuyi@bytedance.com/).
Thanks.
On Fri, Sep 15, 2023 at 4:57 AM Chuyi Zhou <zhouchuyi@bytedance.com> wrote:
>
> Hello.
>
> 在 2023/9/15 07:26, Andrii Nakryiko 写道:
> > On Tue, Sep 12, 2023 at 12:02 AM Chuyi Zhou <zhouchuyi@bytedance.com> wrote:
> >>
> >> This Patch adds kfuncs bpf_iter_css_{pre,post}_{new,next,destroy} which
> >> allow creation and manipulation of struct bpf_iter_css in open-coded
> >> iterator style. These kfuncs actually wrapps css_next_descendant_{pre,
> >> post}. BPF programs can use these kfuncs through bpf_for_each macro for
> >> iteration of all descendant css under a root css.
> >>
> >> Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
> >> ---
> >> include/uapi/linux/bpf.h | 8 +++++
> >> kernel/bpf/helpers.c | 6 ++++
> >> kernel/bpf/task_iter.c | 53 ++++++++++++++++++++++++++++++++++
> >> tools/include/uapi/linux/bpf.h | 8 +++++
> >> tools/lib/bpf/bpf_helpers.h | 12 ++++++++
> >> 5 files changed, 87 insertions(+)
> >>
> >> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> >> index befa55b52e29..57760afc13d0 100644
> >> --- a/include/uapi/linux/bpf.h
> >> +++ b/include/uapi/linux/bpf.h
> >> @@ -7326,4 +7326,12 @@ struct bpf_iter_process {
> >> __u64 __opaque[1];
> >> } __attribute__((aligned(8)));
> >>
> >> +struct bpf_iter_css_pre {
> >> + __u64 __opaque[2];
> >> +} __attribute__((aligned(8)));
> >> +
> >> +struct bpf_iter_css_post {
> >> + __u64 __opaque[2];
> >> +} __attribute__((aligned(8)));
> >> +
> >> #endif /* _UAPI__LINUX_BPF_H__ */
> >> diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
> >> index 9b7d2c6f99d1..ca1f6404af9e 100644
> >> --- a/kernel/bpf/helpers.c
> >> +++ b/kernel/bpf/helpers.c
> >> @@ -2510,6 +2510,12 @@ BTF_ID_FLAGS(func, bpf_iter_css_task_destroy, KF_ITER_DESTROY)
> >> BTF_ID_FLAGS(func, bpf_iter_process_new, KF_ITER_NEW)
> >> BTF_ID_FLAGS(func, bpf_iter_process_next, KF_ITER_NEXT | KF_RET_NULL)
> >> BTF_ID_FLAGS(func, bpf_iter_process_destroy, KF_ITER_DESTROY)
> >> +BTF_ID_FLAGS(func, bpf_iter_css_pre_new, KF_ITER_NEW)
> >> +BTF_ID_FLAGS(func, bpf_iter_css_pre_next, KF_ITER_NEXT | KF_RET_NULL)
> >> +BTF_ID_FLAGS(func, bpf_iter_css_pre_destroy, KF_ITER_DESTROY)
> >> +BTF_ID_FLAGS(func, bpf_iter_css_post_new, KF_ITER_NEW)
> >> +BTF_ID_FLAGS(func, bpf_iter_css_post_next, KF_ITER_NEXT | KF_RET_NULL)
> >> +BTF_ID_FLAGS(func, bpf_iter_css_post_destroy, KF_ITER_DESTROY)
> >> BTF_ID_FLAGS(func, bpf_dynptr_adjust)
> >> BTF_ID_FLAGS(func, bpf_dynptr_is_null)
> >> BTF_ID_FLAGS(func, bpf_dynptr_is_rdonly)
> >> diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c
> >> index 9d1927dc3a06..8963fc779b87 100644
> >> --- a/kernel/bpf/task_iter.c
> >> +++ b/kernel/bpf/task_iter.c
> >> @@ -880,6 +880,59 @@ __bpf_kfunc void bpf_iter_process_destroy(struct bpf_iter_process *it)
> >> {
> >> }
> >>
> >> +struct bpf_iter_css_kern {
> >> + struct cgroup_subsys_state *root;
> >> + struct cgroup_subsys_state *pos;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +__bpf_kfunc int bpf_iter_css_pre_new(struct bpf_iter_css_pre *it,
> >> + struct cgroup_subsys_state *root)
> >
> > similar to my comment on previous patches, please see
> > kernel/bpf/cgroup_iter.c for iter/cgroup iterator program. Let's stay
> > consistent. We have one iterator that accepts parameters defining
> > iteration order and starting cgroup. Unless there are some technical
> > reasons we can't follow similar approach with this open-coded iter,
> > let's use the same approach. We can even reuse
> > BPF_CGROUP_ITER_DESCENDANTS_PRE, BPF_CGROUP_ITER_DESCENDANTS_POST,
> > BPF_CGROUP_ITER_ANCESTORS_UP enums.
> >
>
> I know your concern. It would be nice if we keep consistent with
> kernel/bpf/cgroup_iter.c
>
> But this patch actually want to support iterating css
> (cgroup_subsys_state) not cgroup (css is more low lever).
> With css_iter we can do something like
> "for_each_mem_cgroup_tree/cpuset_for_each_descendant_pre"
> in BPF Progs which is hard for cgroup_iter. In the future we can use
> this iterator to plug some customizable policy in other resource control
> system.
That's fine if it's not exactly cgroup iter and returns a different
kernel object. But let's at least consistently use
BPF_CGROUP_ITER_DESCENDANTS_PRE/BPF_CGROUP_ITER_DESCENDANTS_POST/BPF_CGROUP_ITER_ANCESTORS_UP
approach as a way to specify iteration order?
>
> BTW, what I did in RFC actually very similar with the approach of
> cgroup_iter.
> (https://lore.kernel.org/all/20230827072057.1591929-4-zhouchuyi@bytedance.com/).
>
> Thanks.
Hi Chuyi,
kernel test robot noticed the following build errors:
[auto build test ERROR on bpf-next/master]
url: https://github.com/intel-lab-lkp/linux/commits/Chuyi-Zhou/cgroup-Prepare-for-using-css_task_iter_-in-BPF/20230912-150454
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link: https://lore.kernel.org/r/20230912070149.969939-5-zhouchuyi%40bytedance.com
patch subject: [PATCH bpf-next v2 4/6] bpf: Introduce css_descendant open-coded iterator kfuncs
config: arm-randconfig-r032-20230913 (https://download.01.org/0day-ci/archive/20230913/202309131634.hJlxw7NA-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230913/202309131634.hJlxw7NA-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202309131634.hJlxw7NA-lkp@intel.com/
All errors (new ones prefixed by >>):
kernel/bpf/task_iter.c:810:17: warning: no previous prototype for function 'bpf_iter_css_task_new' [-Wmissing-prototypes]
810 | __bpf_kfunc int bpf_iter_css_task_new(struct bpf_iter_css_task *it,
| ^
kernel/bpf/task_iter.c:810:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
810 | __bpf_kfunc int bpf_iter_css_task_new(struct bpf_iter_css_task *it,
| ^
| static
kernel/bpf/task_iter.c:835:33: warning: no previous prototype for function 'bpf_iter_css_task_next' [-Wmissing-prototypes]
835 | __bpf_kfunc struct task_struct *bpf_iter_css_task_next(struct bpf_iter_css_task *it)
| ^
kernel/bpf/task_iter.c:835:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
835 | __bpf_kfunc struct task_struct *bpf_iter_css_task_next(struct bpf_iter_css_task *it)
| ^
| static
kernel/bpf/task_iter.c:844:18: warning: no previous prototype for function 'bpf_iter_css_task_destroy' [-Wmissing-prototypes]
844 | __bpf_kfunc void bpf_iter_css_task_destroy(struct bpf_iter_css_task *it)
| ^
kernel/bpf/task_iter.c:844:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
844 | __bpf_kfunc void bpf_iter_css_task_destroy(struct bpf_iter_css_task *it)
| ^
| static
kernel/bpf/task_iter.c:858:17: warning: no previous prototype for function 'bpf_iter_process_new' [-Wmissing-prototypes]
858 | __bpf_kfunc int bpf_iter_process_new(struct bpf_iter_process *it)
| ^
kernel/bpf/task_iter.c:858:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
858 | __bpf_kfunc int bpf_iter_process_new(struct bpf_iter_process *it)
| ^
| static
kernel/bpf/task_iter.c:870:33: warning: no previous prototype for function 'bpf_iter_process_next' [-Wmissing-prototypes]
870 | __bpf_kfunc struct task_struct *bpf_iter_process_next(struct bpf_iter_process *it)
| ^
kernel/bpf/task_iter.c:870:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
870 | __bpf_kfunc struct task_struct *bpf_iter_process_next(struct bpf_iter_process *it)
| ^
| static
kernel/bpf/task_iter.c:879:18: warning: no previous prototype for function 'bpf_iter_process_destroy' [-Wmissing-prototypes]
879 | __bpf_kfunc void bpf_iter_process_destroy(struct bpf_iter_process *it)
| ^
kernel/bpf/task_iter.c:879:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
879 | __bpf_kfunc void bpf_iter_process_destroy(struct bpf_iter_process *it)
| ^
| static
kernel/bpf/task_iter.c:888:17: warning: no previous prototype for function 'bpf_iter_css_pre_new' [-Wmissing-prototypes]
888 | __bpf_kfunc int bpf_iter_css_pre_new(struct bpf_iter_css_pre *it,
| ^
kernel/bpf/task_iter.c:888:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
888 | __bpf_kfunc int bpf_iter_css_pre_new(struct bpf_iter_css_pre *it,
| ^
| static
kernel/bpf/task_iter.c:900:41: warning: no previous prototype for function 'bpf_iter_css_pre_next' [-Wmissing-prototypes]
900 | __bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_pre_next(struct bpf_iter_css_pre *it)
| ^
kernel/bpf/task_iter.c:900:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
900 | __bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_pre_next(struct bpf_iter_css_pre *it)
| ^
| static
kernel/bpf/task_iter.c:908:18: warning: no previous prototype for function 'bpf_iter_css_pre_destroy' [-Wmissing-prototypes]
908 | __bpf_kfunc void bpf_iter_css_pre_destroy(struct bpf_iter_css_pre *it)
| ^
kernel/bpf/task_iter.c:908:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
908 | __bpf_kfunc void bpf_iter_css_pre_destroy(struct bpf_iter_css_pre *it)
| ^
| static
kernel/bpf/task_iter.c:912:17: warning: no previous prototype for function 'bpf_iter_css_post_new' [-Wmissing-prototypes]
912 | __bpf_kfunc int bpf_iter_css_post_new(struct bpf_iter_css_post *it,
| ^
kernel/bpf/task_iter.c:912:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
912 | __bpf_kfunc int bpf_iter_css_post_new(struct bpf_iter_css_post *it,
| ^
| static
kernel/bpf/task_iter.c:924:41: warning: no previous prototype for function 'bpf_iter_css_post_next' [-Wmissing-prototypes]
924 | __bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_post_next(struct bpf_iter_css_post *it)
| ^
kernel/bpf/task_iter.c:924:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
924 | __bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_post_next(struct bpf_iter_css_post *it)
| ^
| static
kernel/bpf/task_iter.c:932:18: warning: no previous prototype for function 'bpf_iter_css_post_destroy' [-Wmissing-prototypes]
932 | __bpf_kfunc void bpf_iter_css_post_destroy(struct bpf_iter_css_post *it)
| ^
kernel/bpf/task_iter.c:932:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
932 | __bpf_kfunc void bpf_iter_css_post_destroy(struct bpf_iter_css_post *it)
| ^
| static
>> kernel/bpf/task_iter.c:893:2: error: call to '__compiletime_assert_389' declared with 'error' attribute: BUILD_BUG_ON failed: sizeof(struct bpf_iter_css_kern) != sizeof(struct bpf_iter_css_pre)
893 | BUILD_BUG_ON(sizeof(struct bpf_iter_css_kern) != sizeof(struct bpf_iter_css_pre));
| ^
include/linux/build_bug.h:50:2: note: expanded from macro 'BUILD_BUG_ON'
50 | BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
| ^
include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG'
39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
| ^
include/linux/compiler_types.h:425:2: note: expanded from macro 'compiletime_assert'
425 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
| ^
include/linux/compiler_types.h:413:2: note: expanded from macro '_compiletime_assert'
413 | __compiletime_assert(condition, msg, prefix, suffix)
| ^
include/linux/compiler_types.h:406:4: note: expanded from macro '__compiletime_assert'
406 | prefix ## suffix(); \
| ^
<scratch space>:6:1: note: expanded from here
6 | __compiletime_assert_389
| ^
>> kernel/bpf/task_iter.c:917:2: error: call to '__compiletime_assert_391' declared with 'error' attribute: BUILD_BUG_ON failed: sizeof(struct bpf_iter_css_kern) != sizeof(struct bpf_iter_css_post)
917 | BUILD_BUG_ON(sizeof(struct bpf_iter_css_kern) != sizeof(struct bpf_iter_css_post));
| ^
include/linux/build_bug.h:50:2: note: expanded from macro 'BUILD_BUG_ON'
50 | BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
| ^
include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG'
39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
| ^
include/linux/compiler_types.h:425:2: note: expanded from macro 'compiletime_assert'
425 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
| ^
include/linux/compiler_types.h:413:2: note: expanded from macro '_compiletime_assert'
413 | __compiletime_assert(condition, msg, prefix, suffix)
| ^
include/linux/compiler_types.h:406:4: note: expanded from macro '__compiletime_assert'
406 | prefix ## suffix(); \
| ^
<scratch space>:14:1: note: expanded from here
14 | __compiletime_assert_391
| ^
12 warnings and 2 errors generated.
vim +893 kernel/bpf/task_iter.c
887
888 __bpf_kfunc int bpf_iter_css_pre_new(struct bpf_iter_css_pre *it,
889 struct cgroup_subsys_state *root)
890 {
891 struct bpf_iter_css_kern *kit = (void *)it;
892
> 893 BUILD_BUG_ON(sizeof(struct bpf_iter_css_kern) != sizeof(struct bpf_iter_css_pre));
894 BUILD_BUG_ON(__alignof__(struct bpf_iter_css_kern) != __alignof__(struct bpf_iter_css_pre));
895 kit->root = root;
896 kit->pos = NULL;
897 return 0;
898 }
899
900 __bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_pre_next(struct bpf_iter_css_pre *it)
901 {
902 struct bpf_iter_css_kern *kit = (void *)it;
903
904 kit->pos = css_next_descendant_pre(kit->pos, kit->root);
905 return kit->pos;
906 }
907
908 __bpf_kfunc void bpf_iter_css_pre_destroy(struct bpf_iter_css_pre *it)
909 {
910 }
911
912 __bpf_kfunc int bpf_iter_css_post_new(struct bpf_iter_css_post *it,
913 struct cgroup_subsys_state *root)
914 {
915 struct bpf_iter_css_kern *kit = (void *)it;
916
> 917 BUILD_BUG_ON(sizeof(struct bpf_iter_css_kern) != sizeof(struct bpf_iter_css_post));
918 BUILD_BUG_ON(__alignof__(struct bpf_iter_css_kern) != __alignof__(struct bpf_iter_css_post));
919 kit->root = root;
920 kit->pos = NULL;
921 return 0;
922 }
923
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Hi Chuyi,
kernel test robot noticed the following build warnings:
[auto build test WARNING on bpf-next/master]
url: https://github.com/intel-lab-lkp/linux/commits/Chuyi-Zhou/cgroup-Prepare-for-using-css_task_iter_-in-BPF/20230912-150454
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link: https://lore.kernel.org/r/20230912070149.969939-5-zhouchuyi%40bytedance.com
patch subject: [PATCH bpf-next v2 4/6] bpf: Introduce css_descendant open-coded iterator kfuncs
config: hexagon-randconfig-r032-20230913 (https://download.01.org/0day-ci/archive/20230913/202309131621.h5ogfV0Z-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230913/202309131621.h5ogfV0Z-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202309131621.h5ogfV0Z-lkp@intel.com/
All warnings (new ones prefixed by >>):
573 | val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
| ~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
35 | #define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
| ^
In file included from kernel/bpf/task_iter.c:9:
In file included from include/linux/filter.h:9:
In file included from include/linux/bpf.h:31:
In file included from include/linux/memcontrol.h:13:
In file included from include/linux/cgroup.h:26:
In file included from include/linux/kernel_stat.h:9:
In file included from include/linux/interrupt.h:11:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/hexagon/include/asm/io.h:337:
include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
584 | __raw_writeb(value, PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
594 | __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
604 | __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
kernel/bpf/task_iter.c:820:7: error: use of undeclared identifier 'CSS_TASK_ITER_PROCS'
820 | case CSS_TASK_ITER_PROCS | CSS_TASK_ITER_THREADED:
| ^
kernel/bpf/task_iter.c:820:29: error: use of undeclared identifier 'CSS_TASK_ITER_THREADED'
820 | case CSS_TASK_ITER_PROCS | CSS_TASK_ITER_THREADED:
| ^
kernel/bpf/task_iter.c:821:7: error: use of undeclared identifier 'CSS_TASK_ITER_PROCS'
821 | case CSS_TASK_ITER_PROCS:
| ^
kernel/bpf/task_iter.c:828:24: error: invalid application of 'sizeof' to an incomplete type 'struct css_task_iter'
828 | kit->css_it = kzalloc(sizeof(struct css_task_iter), GFP_KERNEL);
| ^ ~~~~~~~~~~~~~~~~~~~~~~
kernel/bpf/task_iter.c:807:9: note: forward declaration of 'struct css_task_iter'
807 | struct css_task_iter *css_it;
| ^
kernel/bpf/task_iter.c:831:2: error: call to undeclared function 'css_task_iter_start'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
831 | css_task_iter_start(css, flags, kit->css_it);
| ^
kernel/bpf/task_iter.c:831:2: note: did you mean '__sg_page_iter_start'?
include/linux/scatterlist.h:573:6: note: '__sg_page_iter_start' declared here
573 | void __sg_page_iter_start(struct sg_page_iter *piter,
| ^
kernel/bpf/task_iter.c:810:17: warning: no previous prototype for function 'bpf_iter_css_task_new' [-Wmissing-prototypes]
810 | __bpf_kfunc int bpf_iter_css_task_new(struct bpf_iter_css_task *it,
| ^
kernel/bpf/task_iter.c:810:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
810 | __bpf_kfunc int bpf_iter_css_task_new(struct bpf_iter_css_task *it,
| ^
| static
kernel/bpf/task_iter.c:841:9: error: call to undeclared function 'css_task_iter_next'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
841 | return css_task_iter_next(kit->css_it);
| ^
kernel/bpf/task_iter.c:841:9: error: incompatible integer to pointer conversion returning 'int' from a function with result type 'struct task_struct *' [-Wint-conversion]
841 | return css_task_iter_next(kit->css_it);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
kernel/bpf/task_iter.c:835:33: warning: no previous prototype for function 'bpf_iter_css_task_next' [-Wmissing-prototypes]
835 | __bpf_kfunc struct task_struct *bpf_iter_css_task_next(struct bpf_iter_css_task *it)
| ^
kernel/bpf/task_iter.c:835:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
835 | __bpf_kfunc struct task_struct *bpf_iter_css_task_next(struct bpf_iter_css_task *it)
| ^
| static
kernel/bpf/task_iter.c:850:2: error: call to undeclared function 'css_task_iter_end'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
850 | css_task_iter_end(kit->css_it);
| ^
kernel/bpf/task_iter.c:844:18: warning: no previous prototype for function 'bpf_iter_css_task_destroy' [-Wmissing-prototypes]
844 | __bpf_kfunc void bpf_iter_css_task_destroy(struct bpf_iter_css_task *it)
| ^
kernel/bpf/task_iter.c:844:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
844 | __bpf_kfunc void bpf_iter_css_task_destroy(struct bpf_iter_css_task *it)
| ^
| static
kernel/bpf/task_iter.c:858:17: warning: no previous prototype for function 'bpf_iter_process_new' [-Wmissing-prototypes]
858 | __bpf_kfunc int bpf_iter_process_new(struct bpf_iter_process *it)
| ^
kernel/bpf/task_iter.c:858:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
858 | __bpf_kfunc int bpf_iter_process_new(struct bpf_iter_process *it)
| ^
| static
kernel/bpf/task_iter.c:870:33: warning: no previous prototype for function 'bpf_iter_process_next' [-Wmissing-prototypes]
870 | __bpf_kfunc struct task_struct *bpf_iter_process_next(struct bpf_iter_process *it)
| ^
kernel/bpf/task_iter.c:870:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
870 | __bpf_kfunc struct task_struct *bpf_iter_process_next(struct bpf_iter_process *it)
| ^
| static
kernel/bpf/task_iter.c:879:18: warning: no previous prototype for function 'bpf_iter_process_destroy' [-Wmissing-prototypes]
879 | __bpf_kfunc void bpf_iter_process_destroy(struct bpf_iter_process *it)
| ^
kernel/bpf/task_iter.c:879:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
879 | __bpf_kfunc void bpf_iter_process_destroy(struct bpf_iter_process *it)
| ^
| static
>> kernel/bpf/task_iter.c:888:17: warning: no previous prototype for function 'bpf_iter_css_pre_new' [-Wmissing-prototypes]
888 | __bpf_kfunc int bpf_iter_css_pre_new(struct bpf_iter_css_pre *it,
| ^
kernel/bpf/task_iter.c:888:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
888 | __bpf_kfunc int bpf_iter_css_pre_new(struct bpf_iter_css_pre *it,
| ^
| static
kernel/bpf/task_iter.c:904:13: error: call to undeclared function 'css_next_descendant_pre'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
904 | kit->pos = css_next_descendant_pre(kit->pos, kit->root);
| ^
kernel/bpf/task_iter.c:904:11: error: incompatible integer to pointer conversion assigning to 'struct cgroup_subsys_state *' from 'int' [-Wint-conversion]
904 | kit->pos = css_next_descendant_pre(kit->pos, kit->root);
| ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> kernel/bpf/task_iter.c:900:41: warning: no previous prototype for function 'bpf_iter_css_pre_next' [-Wmissing-prototypes]
900 | __bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_pre_next(struct bpf_iter_css_pre *it)
| ^
kernel/bpf/task_iter.c:900:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
900 | __bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_pre_next(struct bpf_iter_css_pre *it)
| ^
| static
>> kernel/bpf/task_iter.c:908:18: warning: no previous prototype for function 'bpf_iter_css_pre_destroy' [-Wmissing-prototypes]
908 | __bpf_kfunc void bpf_iter_css_pre_destroy(struct bpf_iter_css_pre *it)
| ^
kernel/bpf/task_iter.c:908:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
908 | __bpf_kfunc void bpf_iter_css_pre_destroy(struct bpf_iter_css_pre *it)
| ^
| static
>> kernel/bpf/task_iter.c:912:17: warning: no previous prototype for function 'bpf_iter_css_post_new' [-Wmissing-prototypes]
912 | __bpf_kfunc int bpf_iter_css_post_new(struct bpf_iter_css_post *it,
| ^
kernel/bpf/task_iter.c:912:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
912 | __bpf_kfunc int bpf_iter_css_post_new(struct bpf_iter_css_post *it,
| ^
| static
kernel/bpf/task_iter.c:928:13: error: call to undeclared function 'css_next_descendant_post'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
928 | kit->pos = css_next_descendant_post(kit->pos, kit->root);
| ^
kernel/bpf/task_iter.c:928:11: error: incompatible integer to pointer conversion assigning to 'struct cgroup_subsys_state *' from 'int' [-Wint-conversion]
928 | kit->pos = css_next_descendant_post(kit->pos, kit->root);
| ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> kernel/bpf/task_iter.c:924:41: warning: no previous prototype for function 'bpf_iter_css_post_next' [-Wmissing-prototypes]
924 | __bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_post_next(struct bpf_iter_css_post *it)
| ^
kernel/bpf/task_iter.c:924:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
924 | __bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_post_next(struct bpf_iter_css_post *it)
| ^
| static
>> kernel/bpf/task_iter.c:932:18: warning: no previous prototype for function 'bpf_iter_css_post_destroy' [-Wmissing-prototypes]
932 | __bpf_kfunc void bpf_iter_css_post_destroy(struct bpf_iter_css_post *it)
| ^
kernel/bpf/task_iter.c:932:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
932 | __bpf_kfunc void bpf_iter_css_post_destroy(struct bpf_iter_css_post *it)
| ^
| static
18 warnings and 12 errors generated.
vim +/bpf_iter_css_pre_new +888 kernel/bpf/task_iter.c
878
> 879 __bpf_kfunc void bpf_iter_process_destroy(struct bpf_iter_process *it)
880 {
881 }
882
883 struct bpf_iter_css_kern {
884 struct cgroup_subsys_state *root;
885 struct cgroup_subsys_state *pos;
886 } __attribute__((aligned(8)));
887
> 888 __bpf_kfunc int bpf_iter_css_pre_new(struct bpf_iter_css_pre *it,
889 struct cgroup_subsys_state *root)
890 {
891 struct bpf_iter_css_kern *kit = (void *)it;
892
893 BUILD_BUG_ON(sizeof(struct bpf_iter_css_kern) != sizeof(struct bpf_iter_css_pre));
894 BUILD_BUG_ON(__alignof__(struct bpf_iter_css_kern) != __alignof__(struct bpf_iter_css_pre));
895 kit->root = root;
896 kit->pos = NULL;
897 return 0;
898 }
899
> 900 __bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_pre_next(struct bpf_iter_css_pre *it)
901 {
902 struct bpf_iter_css_kern *kit = (void *)it;
903
> 904 kit->pos = css_next_descendant_pre(kit->pos, kit->root);
905 return kit->pos;
906 }
907
> 908 __bpf_kfunc void bpf_iter_css_pre_destroy(struct bpf_iter_css_pre *it)
909 {
910 }
911
> 912 __bpf_kfunc int bpf_iter_css_post_new(struct bpf_iter_css_post *it,
913 struct cgroup_subsys_state *root)
914 {
915 struct bpf_iter_css_kern *kit = (void *)it;
916
917 BUILD_BUG_ON(sizeof(struct bpf_iter_css_kern) != sizeof(struct bpf_iter_css_post));
918 BUILD_BUG_ON(__alignof__(struct bpf_iter_css_kern) != __alignof__(struct bpf_iter_css_post));
919 kit->root = root;
920 kit->pos = NULL;
921 return 0;
922 }
923
> 924 __bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_post_next(struct bpf_iter_css_post *it)
925 {
926 struct bpf_iter_css_kern *kit = (void *)it;
927
> 928 kit->pos = css_next_descendant_post(kit->pos, kit->root);
929 return kit->pos;
930 }
931
> 932 __bpf_kfunc void bpf_iter_css_post_destroy(struct bpf_iter_css_post *it)
933 {
934 }
935
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Hi Chuyi,
kernel test robot noticed the following build warnings:
[auto build test WARNING on bpf-next/master]
url: https://github.com/intel-lab-lkp/linux/commits/Chuyi-Zhou/cgroup-Prepare-for-using-css_task_iter_-in-BPF/20230912-150454
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link: https://lore.kernel.org/r/20230912070149.969939-5-zhouchuyi%40bytedance.com
patch subject: [PATCH bpf-next v2 4/6] bpf: Introduce css_descendant open-coded iterator kfuncs
config: s390-defconfig (https://download.01.org/0day-ci/archive/20230913/202309131500.J19z0Dil-lkp@intel.com/config)
compiler: s390-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230913/202309131500.J19z0Dil-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202309131500.J19z0Dil-lkp@intel.com/
All warnings (new ones prefixed by >>):
kernel/bpf/task_iter.c:810:17: warning: no previous prototype for 'bpf_iter_css_task_new' [-Wmissing-prototypes]
810 | __bpf_kfunc int bpf_iter_css_task_new(struct bpf_iter_css_task *it,
| ^~~~~~~~~~~~~~~~~~~~~
kernel/bpf/task_iter.c:835:33: warning: no previous prototype for 'bpf_iter_css_task_next' [-Wmissing-prototypes]
835 | __bpf_kfunc struct task_struct *bpf_iter_css_task_next(struct bpf_iter_css_task *it)
| ^~~~~~~~~~~~~~~~~~~~~~
kernel/bpf/task_iter.c:844:18: warning: no previous prototype for 'bpf_iter_css_task_destroy' [-Wmissing-prototypes]
844 | __bpf_kfunc void bpf_iter_css_task_destroy(struct bpf_iter_css_task *it)
| ^~~~~~~~~~~~~~~~~~~~~~~~~
kernel/bpf/task_iter.c:858:17: warning: no previous prototype for 'bpf_iter_process_new' [-Wmissing-prototypes]
858 | __bpf_kfunc int bpf_iter_process_new(struct bpf_iter_process *it)
| ^~~~~~~~~~~~~~~~~~~~
kernel/bpf/task_iter.c:870:33: warning: no previous prototype for 'bpf_iter_process_next' [-Wmissing-prototypes]
870 | __bpf_kfunc struct task_struct *bpf_iter_process_next(struct bpf_iter_process *it)
| ^~~~~~~~~~~~~~~~~~~~~
kernel/bpf/task_iter.c:879:18: warning: no previous prototype for 'bpf_iter_process_destroy' [-Wmissing-prototypes]
879 | __bpf_kfunc void bpf_iter_process_destroy(struct bpf_iter_process *it)
| ^~~~~~~~~~~~~~~~~~~~~~~~
>> kernel/bpf/task_iter.c:888:17: warning: no previous prototype for 'bpf_iter_css_pre_new' [-Wmissing-prototypes]
888 | __bpf_kfunc int bpf_iter_css_pre_new(struct bpf_iter_css_pre *it,
| ^~~~~~~~~~~~~~~~~~~~
>> kernel/bpf/task_iter.c:900:41: warning: no previous prototype for 'bpf_iter_css_pre_next' [-Wmissing-prototypes]
900 | __bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_pre_next(struct bpf_iter_css_pre *it)
| ^~~~~~~~~~~~~~~~~~~~~
>> kernel/bpf/task_iter.c:908:18: warning: no previous prototype for 'bpf_iter_css_pre_destroy' [-Wmissing-prototypes]
908 | __bpf_kfunc void bpf_iter_css_pre_destroy(struct bpf_iter_css_pre *it)
| ^~~~~~~~~~~~~~~~~~~~~~~~
>> kernel/bpf/task_iter.c:912:17: warning: no previous prototype for 'bpf_iter_css_post_new' [-Wmissing-prototypes]
912 | __bpf_kfunc int bpf_iter_css_post_new(struct bpf_iter_css_post *it,
| ^~~~~~~~~~~~~~~~~~~~~
>> kernel/bpf/task_iter.c:924:41: warning: no previous prototype for 'bpf_iter_css_post_next' [-Wmissing-prototypes]
924 | __bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_post_next(struct bpf_iter_css_post *it)
| ^~~~~~~~~~~~~~~~~~~~~~
>> kernel/bpf/task_iter.c:932:18: warning: no previous prototype for 'bpf_iter_css_post_destroy' [-Wmissing-prototypes]
932 | __bpf_kfunc void bpf_iter_css_post_destroy(struct bpf_iter_css_post *it)
| ^~~~~~~~~~~~~~~~~~~~~~~~~
vim +/bpf_iter_css_pre_new +888 kernel/bpf/task_iter.c
887
> 888 __bpf_kfunc int bpf_iter_css_pre_new(struct bpf_iter_css_pre *it,
889 struct cgroup_subsys_state *root)
890 {
891 struct bpf_iter_css_kern *kit = (void *)it;
892
893 BUILD_BUG_ON(sizeof(struct bpf_iter_css_kern) != sizeof(struct bpf_iter_css_pre));
894 BUILD_BUG_ON(__alignof__(struct bpf_iter_css_kern) != __alignof__(struct bpf_iter_css_pre));
895 kit->root = root;
896 kit->pos = NULL;
897 return 0;
898 }
899
> 900 __bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_pre_next(struct bpf_iter_css_pre *it)
901 {
902 struct bpf_iter_css_kern *kit = (void *)it;
903
904 kit->pos = css_next_descendant_pre(kit->pos, kit->root);
905 return kit->pos;
906 }
907
> 908 __bpf_kfunc void bpf_iter_css_pre_destroy(struct bpf_iter_css_pre *it)
909 {
910 }
911
> 912 __bpf_kfunc int bpf_iter_css_post_new(struct bpf_iter_css_post *it,
913 struct cgroup_subsys_state *root)
914 {
915 struct bpf_iter_css_kern *kit = (void *)it;
916
917 BUILD_BUG_ON(sizeof(struct bpf_iter_css_kern) != sizeof(struct bpf_iter_css_post));
918 BUILD_BUG_ON(__alignof__(struct bpf_iter_css_kern) != __alignof__(struct bpf_iter_css_post));
919 kit->root = root;
920 kit->pos = NULL;
921 return 0;
922 }
923
> 924 __bpf_kfunc struct cgroup_subsys_state *bpf_iter_css_post_next(struct bpf_iter_css_post *it)
925 {
926 struct bpf_iter_css_kern *kit = (void *)it;
927
928 kit->pos = css_next_descendant_post(kit->pos, kit->root);
929 return kit->pos;
930 }
931
> 932 __bpf_kfunc void bpf_iter_css_post_destroy(struct bpf_iter_css_post *it)
933 {
934 }
935
--
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