Follow the docs at Documentation/bpf/kfuncs.rst:
- declare the function with `__bpf_kfunc`
- disables missing prototype warnings, which allows to remove them from
include/linux/hid-bpf.h
Removing the prototypes is not an issue because we currently have to
redeclare them when writing the BPF program. They will eventually be
generated by bpftool directly AFAIU.
Signed-off-by: Benjamin Tissoires <bentiss@xxxxxxxxxx>
---
drivers/hid/bpf/hid_bpf_dispatch.c | 22 +++++++++++++++++-----
include/linux/hid_bpf.h | 11 -----------
2 files changed, 17 insertions(+), 16 deletions(-)
diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c
index 5111d1fef0d3..119e4f03df55 100644
--- a/drivers/hid/bpf/hid_bpf_dispatch.c
+++ b/drivers/hid/bpf/hid_bpf_dispatch.c
@@ -143,6 +143,11 @@ u8 *call_hid_bpf_rdesc_fixup(struct hid_device *hdev, u8 *rdesc, unsigned int *s
}
EXPORT_SYMBOL_GPL(call_hid_bpf_rdesc_fixup);
+/* Disables missing prototype warnings */
+__diag_push();
+__diag_ignore_all("-Wmissing-prototypes",
+ "Global kfuncs as their definitions will be in BTF");
+
/**
* hid_bpf_get_data - Get the kernel memory pointer associated with the context @ctx
*
@@ -152,7 +157,7 @@ EXPORT_SYMBOL_GPL(call_hid_bpf_rdesc_fixup);
*
* @returns %NULL on error, an %__u8 memory pointer on success
*/
-noinline __u8 *
+__bpf_kfunc __u8 *
hid_bpf_get_data(struct hid_bpf_ctx *ctx, unsigned int offset, const size_t rdwr_buf_size)
{
struct hid_bpf_ctx_kern *ctx_kern;
@@ -167,6 +172,7 @@ hid_bpf_get_data(struct hid_bpf_ctx *ctx, unsigned int offset, const size_t rdwr
return ctx_kern->data + offset;
}
+__diag_pop(); /* missing prototype warnings */
/*
* The following set contains all functions we agree BPF programs
@@ -274,6 +280,11 @@ static int do_hid_bpf_attach_prog(struct hid_device *hdev, int prog_fd, struct b
return fd;
}
+/* Disables missing prototype warnings */
+__diag_push();
+__diag_ignore_all("-Wmissing-prototypes",
+ "Global kfuncs as their definitions will be in BTF");
+
/**
* hid_bpf_attach_prog - Attach the given @prog_fd to the given HID device
*
@@ -286,7 +297,7 @@ static int do_hid_bpf_attach_prog(struct hid_device *hdev, int prog_fd, struct b
* is pinned to the BPF file system).
*/
/* called from syscall */
-noinline int
+__bpf_kfunc int
hid_bpf_attach_prog(unsigned int hid_id, int prog_fd, __u32 flags)
{
struct hid_device *hdev;
@@ -328,7 +339,7 @@ hid_bpf_attach_prog(unsigned int hid_id, int prog_fd, __u32 flags)
*
* @returns A pointer to &struct hid_bpf_ctx on success, %NULL on error.
*/
-noinline struct hid_bpf_ctx *
+__bpf_kfunc struct hid_bpf_ctx *
hid_bpf_allocate_context(unsigned int hid_id)
{
struct hid_device *hdev;
@@ -359,7 +370,7 @@ hid_bpf_allocate_context(unsigned int hid_id)
* @ctx: the HID-BPF context to release
*
*/
-noinline void
+__bpf_kfunc void
hid_bpf_release_context(struct hid_bpf_ctx *ctx)
{
struct hid_bpf_ctx_kern *ctx_kern;
@@ -380,7 +391,7 @@ hid_bpf_release_context(struct hid_bpf_ctx *ctx)
*
* @returns %0 on success, a negative error code otherwise.
*/
-noinline int
+__bpf_kfunc int
hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz,
enum hid_report_type rtype, enum hid_class_request reqtype)
{
@@ -448,6 +459,7 @@ hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz,
kfree(dma_data);
return ret;
}
+__diag_pop(); /* missing prototype warnings */
/* our HID-BPF entrypoints */
BTF_SET8_START(hid_bpf_fmodret_ids)
diff --git a/include/linux/hid_bpf.h b/include/linux/hid_bpf.h
index 840cd254172d..7118ac28d468 100644
--- a/include/linux/hid_bpf.h
+++ b/include/linux/hid_bpf.h
@@ -77,17 +77,6 @@ enum hid_bpf_attach_flags {
int hid_bpf_device_event(struct hid_bpf_ctx *ctx);
int hid_bpf_rdesc_fixup(struct hid_bpf_ctx *ctx);
-/* Following functions are kfunc that we export to BPF programs */
-/* available everywhere in HID-BPF */
-__u8 *hid_bpf_get_data(struct hid_bpf_ctx *ctx, unsigned int offset, const size_t __sz);
-
-/* only available in syscall */
-int hid_bpf_attach_prog(unsigned int hid_id, int prog_fd, __u32 flags);
-int hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz,
- enum hid_report_type rtype, enum hid_class_request reqtype);
-struct hid_bpf_ctx *hid_bpf_allocate_context(unsigned int hid_id);
-void hid_bpf_release_context(struct hid_bpf_ctx *ctx);
-
/*
* Below is HID internal
*/
--
2.43.0
