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selftests/hid: convert the hid_bpf selftests with struct_ops

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We drop the need for the attach() bpf syscall, but we need to set up
the hid_id field before calling __load().

The .bpf.c part is mechanical: we create one struct_ops per HID-BPF
program, as all the tests are for one program at a time.

Link: https://lore.kernel.org/r/20240608-hid_bpf_struct_ops-v3-4-6ac6ade58329@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
This commit is contained in:
Benjamin Tissoires 2024-06-08 11:01:16 +02:00
parent ebc0d8093e
commit d7696738d6
3 changed files with 89 additions and 65 deletions
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59
tools/testing/selftests/hid/hid_bpf.c
View File

@ -460,7 +460,7 @@ FIXTURE(hid_bpf) {
int hid_id;
pthread_t tid;
struct hid *skel;
int hid_links[3]; /* max number of programs loaded in a single test */
struct bpf_link *hid_links[3]; /* max number of programs loaded in a single test */
};
static void detach_bpf(FIXTURE_DATA(hid_bpf) * self)
{
@ -472,7 +472,7 @@ static void detach_bpf(FIXTURE_DATA(hid_bpf) * self)
for (i = 0; i < ARRAY_SIZE(self->hid_links); i++) {
if (self->hid_links[i])
close(self->hid_links[i]);
bpf_link__destroy(self->hid_links[i]);
}
hid__destroy(self->skel);
@ -527,14 +527,7 @@ static void load_programs(const struct test_program programs[],
FIXTURE_DATA(hid_bpf) * self,
const FIXTURE_VARIANT(hid_bpf) * variant)
{
int attach_fd, err = -EINVAL;
struct attach_prog_args args = {
.retval = -1,
};
DECLARE_LIBBPF_OPTS(bpf_test_run_opts, tattr,
.ctx_in = &args,
.ctx_size_in = sizeof(args),
);
int err = -EINVAL;
ASSERT_LE(progs_count, ARRAY_SIZE(self->hid_links))
TH_LOG("too many programs are to be loaded");
@ -545,35 +538,41 @@ static void load_programs(const struct test_program programs[],
for (int i = 0; i < progs_count; i++) {
struct bpf_program *prog;
struct bpf_map *map;
int *ops_hid_id;
prog = bpf_object__find_program_by_name(*self->skel->skeleton->obj,
programs[i].name);
ASSERT_OK_PTR(prog) TH_LOG("can not find program by name '%s'", programs[i].name);
bpf_program__set_autoload(prog, true);
map = bpf_object__find_map_by_name(*self->skel->skeleton->obj,
programs[i].name + 4);
ASSERT_OK_PTR(map) TH_LOG("can not find struct_ops by name '%s'",
programs[i].name + 4);
/* hid_id is the first field of struct hid_bpf_ops */
ops_hid_id = bpf_map__initial_value(map, NULL);
ASSERT_OK_PTR(ops_hid_id) TH_LOG("unable to retrieve struct_ops data");
*ops_hid_id = self->hid_id;
}
err = hid__load(self->skel);
ASSERT_OK(err) TH_LOG("hid_skel_load failed: %d", err);
attach_fd = bpf_program__fd(self->skel->progs.attach_prog);
ASSERT_GE(attach_fd, 0) TH_LOG("locate attach_prog: %d", attach_fd);
for (int i = 0; i < progs_count; i++) {
struct bpf_program *prog;
struct bpf_map *map;
prog = bpf_object__find_program_by_name(*self->skel->skeleton->obj,
programs[i].name);
ASSERT_OK_PTR(prog) TH_LOG("can not find program by name '%s'", programs[i].name);
map = bpf_object__find_map_by_name(*self->skel->skeleton->obj,
programs[i].name + 4);
ASSERT_OK_PTR(map) TH_LOG("can not find struct_ops by name '%s'",
programs[i].name + 4);
args.prog_fd = bpf_program__fd(prog);
args.hid = self->hid_id;
args.insert_head = programs[i].insert_head;
err = bpf_prog_test_run_opts(attach_fd, &tattr);
ASSERT_GE(args.retval, 0)
TH_LOG("attach_hid(%s): %d", programs[i].name, args.retval);
self->hid_links[i] = args.retval;
self->hid_links[i] = bpf_map__attach_struct_ops(map);
ASSERT_OK_PTR(self->hid_links[i]) TH_LOG("failed to attach struct ops '%s'",
programs[i].name + 4);
}
self->hidraw_fd = open_hidraw(self->dev_id);
@ -648,13 +647,17 @@ TEST_F(hid_bpf, test_attach_detach)
{ .name = "hid_first_event" },
{ .name = "hid_second_event" },
};
struct bpf_link *link;
__u8 buf[10] = {0};
int err, link;
int err, link_fd;
LOAD_PROGRAMS(progs);
link = self->hid_links[0];
ASSERT_GT(link, 0) TH_LOG("HID-BPF link not created");
ASSERT_OK_PTR(link) TH_LOG("HID-BPF link not created");
link_fd = bpf_link__fd(link);
ASSERT_GE(link_fd, 0) TH_LOG("HID-BPF link FD not valid");
/* inject one event */
buf[0] = 1;
@ -673,7 +676,7 @@ TEST_F(hid_bpf, test_attach_detach)
/* pin the first program and immediately unpin it */
#define PIN_PATH "/sys/fs/bpf/hid_first_event"
err = bpf_obj_pin(link, PIN_PATH);
err = bpf_obj_pin(link_fd, PIN_PATH);
ASSERT_OK(err) TH_LOG("error while calling bpf_obj_pin");
remove(PIN_PATH);
#undef PIN_PATH

76
tools/testing/selftests/hid/progs/hid.c
View File

@ -14,8 +14,8 @@ struct attach_prog_args {
__u64 callback_check = 52;
__u64 callback2_check = 52;
SEC("?fmod_ret/hid_bpf_device_event")
int BPF_PROG(hid_first_event, struct hid_bpf_ctx *hid_ctx)
SEC("?struct_ops/hid_device_event")
int BPF_PROG(hid_first_event, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
{
__u8 *rw_data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 3 /* size */);
@ -29,8 +29,14 @@ int BPF_PROG(hid_first_event, struct hid_bpf_ctx *hid_ctx)
return hid_ctx->size;
}
SEC("?fmod_ret/hid_bpf_device_event")
int BPF_PROG(hid_second_event, struct hid_bpf_ctx *hid_ctx)
SEC(".struct_ops.link")
struct hid_bpf_ops first_event = {
.hid_device_event = (void *)hid_first_event,
.hid_id = 2,
};
SEC("?struct_ops/hid_device_event")
int BPF_PROG(hid_second_event, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
{
__u8 *rw_data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4 /* size */);
@ -42,8 +48,13 @@ int BPF_PROG(hid_second_event, struct hid_bpf_ctx *hid_ctx)
return hid_ctx->size;
}
SEC("?fmod_ret/hid_bpf_device_event")
int BPF_PROG(hid_change_report_id, struct hid_bpf_ctx *hid_ctx)
SEC(".struct_ops.link")
struct hid_bpf_ops second_event = {
.hid_device_event = (void *)hid_second_event,
};
SEC("?struct_ops/hid_device_event")
int BPF_PROG(hid_change_report_id, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
{
__u8 *rw_data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 3 /* size */);
@ -55,15 +66,10 @@ int BPF_PROG(hid_change_report_id, struct hid_bpf_ctx *hid_ctx)
return 9;
}
SEC("syscall")
int attach_prog(struct attach_prog_args *ctx)
{
ctx->retval = hid_bpf_attach_prog(ctx->hid,
ctx->prog_fd,
ctx->insert_head ? HID_BPF_FLAG_INSERT_HEAD :
HID_BPF_FLAG_NONE);
return 0;
}
SEC(".struct_ops.link")
struct hid_bpf_ops change_report_id = {
.hid_device_event = (void *)hid_change_report_id,
};
struct hid_hw_request_syscall_args {
/* data needs to come at offset 0 so we can use it in calls */
@ -181,7 +187,12 @@ static const __u8 rdesc[] = {
0xc0, /* END_COLLECTION */
};
SEC("?fmod_ret/hid_bpf_rdesc_fixup")
/*
* the following program is marked as sleepable (struct_ops.s).
* This is not strictly mandatory but is a nice test for
* sleepable struct_ops
*/
SEC("?struct_ops.s/hid_rdesc_fixup")
int BPF_PROG(hid_rdesc_fixup, struct hid_bpf_ctx *hid_ctx)
{
__u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4096 /* size */);
@ -200,8 +211,13 @@ int BPF_PROG(hid_rdesc_fixup, struct hid_bpf_ctx *hid_ctx)
return sizeof(rdesc) + 73;
}
SEC("?fmod_ret/hid_bpf_device_event")
int BPF_PROG(hid_test_insert1, struct hid_bpf_ctx *hid_ctx)
SEC(".struct_ops.link")
struct hid_bpf_ops rdesc_fixup = {
.hid_rdesc_fixup = (void *)hid_rdesc_fixup,
};
SEC("?struct_ops/hid_device_event")
int BPF_PROG(hid_test_insert1, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
{
__u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4 /* size */);
@ -217,8 +233,14 @@ int BPF_PROG(hid_test_insert1, struct hid_bpf_ctx *hid_ctx)
return 0;
}
SEC("?fmod_ret/hid_bpf_device_event")
int BPF_PROG(hid_test_insert2, struct hid_bpf_ctx *hid_ctx)
SEC(".struct_ops.link")
struct hid_bpf_ops test_insert1 = {
.hid_device_event = (void *)hid_test_insert1,
.flags = BPF_F_BEFORE,
};
SEC("?struct_ops/hid_device_event")
int BPF_PROG(hid_test_insert2, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
{
__u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4 /* size */);
@ -234,8 +256,13 @@ int BPF_PROG(hid_test_insert2, struct hid_bpf_ctx *hid_ctx)
return 0;
}
SEC("?fmod_ret/hid_bpf_device_event")
int BPF_PROG(hid_test_insert3, struct hid_bpf_ctx *hid_ctx)
SEC(".struct_ops.link")
struct hid_bpf_ops test_insert2 = {
.hid_device_event = (void *)hid_test_insert2,
};
SEC("?struct_ops/hid_device_event")
int BPF_PROG(hid_test_insert3, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
{
__u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4 /* size */);
@ -250,3 +277,8 @@ int BPF_PROG(hid_test_insert3, struct hid_bpf_ctx *hid_ctx)
return 0;
}
SEC(".struct_ops.link")
struct hid_bpf_ops test_insert3 = {
.hid_device_event = (void *)hid_test_insert3,
};

19
tools/testing/selftests/hid/progs/hid_bpf_helpers.h
View File

@ -20,9 +20,6 @@
#define HID_REQ_SET_REPORT HID_REQ_SET_REPORT___not_used
#define HID_REQ_SET_IDLE HID_REQ_SET_IDLE___not_used
#define HID_REQ_SET_PROTOCOL HID_REQ_SET_PROTOCOL___not_used
#define HID_BPF_FLAG_NONE HID_BPF_FLAG_NONE___not_used
#define HID_BPF_FLAG_INSERT_HEAD HID_BPF_FLAG_INSERT_HEAD___not_used
#define HID_BPF_FLAG_MAX HID_BPF_FLAG_MAX___not_used
#include "vmlinux.h"
@ -40,9 +37,6 @@
#undef HID_REQ_SET_REPORT
#undef HID_REQ_SET_IDLE
#undef HID_REQ_SET_PROTOCOL
#undef HID_BPF_FLAG_NONE
#undef HID_BPF_FLAG_INSERT_HEAD
#undef HID_BPF_FLAG_MAX
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
@ -57,10 +51,8 @@ enum hid_report_type {
};
struct hid_bpf_ctx {
__u32 index;
const struct hid_device *hid;
struct hid_device *hid;
__u32 allocated_size;
enum hid_report_type report_type;
union {
__s32 retval;
__s32 size;
@ -76,17 +68,14 @@ enum hid_class_request {
HID_REQ_SET_PROTOCOL = 0x0B,
};
enum hid_bpf_attach_flags {
HID_BPF_FLAG_NONE = 0,
HID_BPF_FLAG_INSERT_HEAD = _BITUL(0),
HID_BPF_FLAG_MAX,
};
#ifndef BPF_F_BEFORE
#define BPF_F_BEFORE (1U << 3)
#endif
/* following are kfuncs exported by HID for HID-BPF */
extern __u8 *hid_bpf_get_data(struct hid_bpf_ctx *ctx,
unsigned int offset,
const size_t __sz) __ksym;
extern int hid_bpf_attach_prog(unsigned int hid_id, int prog_fd, u32 flags) __ksym;
extern struct hid_bpf_ctx *hid_bpf_allocate_context(unsigned int hid_id) __ksym;
extern void hid_bpf_release_context(struct hid_bpf_ctx *ctx) __ksym;
extern int hid_bpf_hw_request(struct hid_bpf_ctx *ctx,