Commit 06507c75 authored by Alexei Starovoitov's avatar Alexei Starovoitov
Browse files

Merge branch 'small-api-fix-for-bpf_wq' 



Benjamin Tissoires says:

====================
Small API fix for bpf_wq

I realized this while having a map containing both a struct bpf_timer and
a struct bpf_wq: the third argument provided to the bpf_wq callback is
not the struct bpf_wq pointer itself, but the pointer to the value in
the map.

Which means that the users need to double cast the provided "value" as
this is not a struct bpf_wq *.

This is a change of API, but there doesn't seem to be much users of bpf_wq
right now, so we should be able to go with this right now.

Signed-off-by: default avatarBenjamin Tissoires <bentiss@kernel.org>
---
Changes in v2:
- amended the selftests to retrieve something from the third argument of
  the callback
- Link to v1: https://lore.kernel.org/r/20240705-fix-wq-v1-0-91b4d82cd825@kernel.org

---
====================

Link: https://lore.kernel.org/r/20240708-fix-wq-v2-0-667e5c9fbd99@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parents cedc12c5 16e86f2e

kernel/bpf/helpers.c

+1 −1
Original line number Diff line number Diff line
@@ -2734,7 +2734,7 @@ __bpf_kfunc int bpf_wq_start(struct bpf_wq *wq, unsigned int flags) 
}



__bpf_kfunc int bpf_wq_set_callback_impl(struct bpf_wq *wq,

					 int (callback_fn)(void *map, int *key, struct bpf_wq *wq),

					 int (callback_fn)(void *map, int *key, void *value),

					 unsigned int flags,

					 void *aux__ign)

{

tools/testing/selftests/bpf/bpf_experimental.h

+1 −1
Original line number Diff line number Diff line
@@ -552,7 +552,7 @@ extern void bpf_iter_css_destroy(struct bpf_iter_css *it) __weak __ksym; 
extern int bpf_wq_init(struct bpf_wq *wq, void *p__map, unsigned int flags) __weak __ksym;

extern int bpf_wq_start(struct bpf_wq *wq, unsigned int flags) __weak __ksym;

extern int bpf_wq_set_callback_impl(struct bpf_wq *wq,

		int (callback_fn)(void *map, int *key, struct bpf_wq *wq),

		int (callback_fn)(void *map, int *key, void *value),

		unsigned int flags__k, void *aux__ign) __ksym;

#define bpf_wq_set_callback(timer, cb, flags) \

	bpf_wq_set_callback_impl(timer, cb, flags, NULL)

tools/testing/selftests/bpf/progs/wq.c

+14 −5
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ struct { 
} hmap_malloc SEC(".maps");



struct elem {

	int ok_offset;

	struct bpf_wq w;

};
@@ -53,7 +54,7 @@ __u32 ok; 
__u32 ok_sleepable;



static int test_elem_callback(void *map, int *key,

		int (callback_fn)(void *map, int *key, struct bpf_wq *wq))

		int (callback_fn)(void *map, int *key, void *value))

{

	struct elem init = {}, *val;

	struct bpf_wq *wq;
@@ -70,6 +71,8 @@ static int test_elem_callback(void *map, int *key, 
	if (!val)

		return -2;



	val->ok_offset = *key;



	wq = &val->w;

	if (bpf_wq_init(wq, map, 0) != 0)

		return -3;
@@ -84,7 +87,7 @@ static int test_elem_callback(void *map, int *key, 
}



static int test_hmap_elem_callback(void *map, int *key,

		int (callback_fn)(void *map, int *key, struct bpf_wq *wq))

		int (callback_fn)(void *map, int *key, void *value))

{

	struct hmap_elem init = {}, *val;

	struct bpf_wq *wq;
@@ -114,7 +117,7 @@ static int test_hmap_elem_callback(void *map, int *key, 
}



/* callback for non sleepable workqueue */

static int wq_callback(void *map, int *key, struct bpf_wq *work)

static int wq_callback(void *map, int *key, void *value)

{

	bpf_kfunc_common_test();

	ok |= (1 << *key);
@@ -122,10 +125,16 @@ static int wq_callback(void *map, int *key, struct bpf_wq *work) 
}



/* callback for sleepable workqueue */

static int wq_cb_sleepable(void *map, int *key, struct bpf_wq *work)

static int wq_cb_sleepable(void *map, int *key, void *value)

{

	struct elem *data = (struct elem *)value;

	int offset = data->ok_offset;



	if (*key != offset)

		return 0;



	bpf_kfunc_call_test_sleepable();

	ok_sleepable |= (1 << *key);

	ok_sleepable |= (1 << offset);

	return 0;

}

tools/testing/selftests/bpf/progs/wq_failures.c

+2 −2
Original line number Diff line number Diff line
@@ -28,14 +28,14 @@ struct { 
} lru SEC(".maps");



/* callback for non sleepable workqueue */

static int wq_callback(void *map, int *key, struct bpf_wq *work)

static int wq_callback(void *map, int *key, void *value)

{

	bpf_kfunc_common_test();

	return 0;

}



/* callback for sleepable workqueue */

static int wq_cb_sleepable(void *map, int *key, struct bpf_wq *work)

static int wq_cb_sleepable(void *map, int *key, void *value)

{

	bpf_kfunc_call_test_sleepable();

	return 0;