2022-08-01 07:31:28

by Tianchen Ding

[permalink] [raw]
Subject: [PATCH 5.10 0/3] fix build error in bpf selftests

We found a compile error when building tools/testing/selftests/bpf/ on 5.10.y.
tools/testing/selftests/bpf/prog_tests/sk_lookup.c:1092:15: error: 'struct bpf_sk_lookup' has no member named 'cookie'
1092 | if (CHECK(ctx.cookie == 0, "ctx.cookie", "no socket selected\n"))
| ^

To fix this bug, this patchset backports three patches from upstream:
https://lore.kernel.org/bpf/[email protected]/

Patch 1 and 2 are necessary for bpf selftests build pass on 5.10.y.
Patch 3 does not impact building stage, but can avoid a test case
failure (by skipping it).

Lorenz Bauer (3):
bpf: Consolidate shared test timing code
bpf: Add PROG_TEST_RUN support for sk_lookup programs
selftests: bpf: Don't run sk_lookup in verifier tests

include/linux/bpf.h | 10 +
include/uapi/linux/bpf.h | 5 +-
net/bpf/test_run.c | 243 +++++++++++++-----
net/core/filter.c | 1 +
tools/include/uapi/linux/bpf.h | 5 +-
tools/testing/selftests/bpf/test_verifier.c | 4 +-
.../selftests/bpf/verifier/ctx_sk_lookup.c | 1 +
7 files changed, 204 insertions(+), 65 deletions(-)

--
2.27.0



2022-08-01 07:31:37

by Tianchen Ding

[permalink] [raw]
Subject: [PATCH 5.10 3/3] selftests: bpf: Don't run sk_lookup in verifier tests

From: Lorenz Bauer <[email protected]>

commit b4f894633fa14d7d46ba7676f950b90a401504bb upstream.

sk_lookup doesn't allow setting data_in for bpf_prog_run. This doesn't
play well with the verifier tests, since they always set a 64 byte
input buffer. Allow not running verifier tests by setting
bpf_test.runs to a negative value and don't run the ctx access case
for sk_lookup. We have dedicated ctx access tests so skipping here
doesn't reduce coverage.

Signed-off-by: Lorenz Bauer <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Signed-off-by: Tianchen Ding <[email protected]>
---
tools/testing/selftests/bpf/test_verifier.c | 4 ++--
tools/testing/selftests/bpf/verifier/ctx_sk_lookup.c | 1 +
2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index a4c55fcb0e7b..0fb92d9a319b 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -100,7 +100,7 @@ struct bpf_test {
enum bpf_prog_type prog_type;
uint8_t flags;
void (*fill_helper)(struct bpf_test *self);
- uint8_t runs;
+ int runs;
#define bpf_testdata_struct_t \
struct { \
uint32_t retval, retval_unpriv; \
@@ -1054,7 +1054,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv,

run_errs = 0;
run_successes = 0;
- if (!alignment_prevented_execution && fd_prog >= 0) {
+ if (!alignment_prevented_execution && fd_prog >= 0 && test->runs >= 0) {
uint32_t expected_val;
int i;

diff --git a/tools/testing/selftests/bpf/verifier/ctx_sk_lookup.c b/tools/testing/selftests/bpf/verifier/ctx_sk_lookup.c
index 2ad5f974451c..fd3b62a084b9 100644
--- a/tools/testing/selftests/bpf/verifier/ctx_sk_lookup.c
+++ b/tools/testing/selftests/bpf/verifier/ctx_sk_lookup.c
@@ -239,6 +239,7 @@
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_SK_LOOKUP,
.expected_attach_type = BPF_SK_LOOKUP,
+ .runs = -1,
},
/* invalid 8-byte reads from a 4-byte fields in bpf_sk_lookup */
{
--
2.27.0


2022-08-01 07:38:02

by Tianchen Ding

[permalink] [raw]
Subject: [PATCH 5.10 2/3] bpf: Add PROG_TEST_RUN support for sk_lookup programs

From: Lorenz Bauer <[email protected]>

commit 7c32e8f8bc33a5f4b113a630857e46634e3e143b upstream.

Allow to pass sk_lookup programs to PROG_TEST_RUN. User space
provides the full bpf_sk_lookup struct as context. Since the
context includes a socket pointer that can't be exposed
to user space we define that PROG_TEST_RUN returns the cookie
of the selected socket or zero in place of the socket pointer.

We don't support testing programs that select a reuseport socket,
since this would mean running another (unrelated) BPF program
from the sk_lookup test handler.

Signed-off-by: Lorenz Bauer <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Signed-off-by: Tianchen Ding <[email protected]>
---
include/linux/bpf.h | 10 ++++
include/uapi/linux/bpf.h | 5 +-
net/bpf/test_run.c | 105 +++++++++++++++++++++++++++++++++
net/core/filter.c | 1 +
tools/include/uapi/linux/bpf.h | 5 +-
5 files changed, 124 insertions(+), 2 deletions(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index f21bc441e3fa..b010d45a1ecd 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1457,6 +1457,9 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
int bpf_prog_test_run_raw_tp(struct bpf_prog *prog,
const union bpf_attr *kattr,
union bpf_attr __user *uattr);
+int bpf_prog_test_run_sk_lookup(struct bpf_prog *prog,
+ const union bpf_attr *kattr,
+ union bpf_attr __user *uattr);
bool btf_ctx_access(int off, int size, enum bpf_access_type type,
const struct bpf_prog *prog,
struct bpf_insn_access_aux *info);
@@ -1671,6 +1674,13 @@ static inline int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
return -ENOTSUPP;
}

+static inline int bpf_prog_test_run_sk_lookup(struct bpf_prog *prog,
+ const union bpf_attr *kattr,
+ union bpf_attr __user *uattr)
+{
+ return -ENOTSUPP;
+}
+
static inline void bpf_map_put(struct bpf_map *map)
{
}
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 0f39fdcb2273..2a234023821e 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -5007,7 +5007,10 @@ struct bpf_pidns_info {

/* User accessible data for SK_LOOKUP programs. Add new fields at the end. */
struct bpf_sk_lookup {
- __bpf_md_ptr(struct bpf_sock *, sk); /* Selected socket */
+ union {
+ __bpf_md_ptr(struct bpf_sock *, sk); /* Selected socket */
+ __u64 cookie; /* Non-zero if socket was selected in PROG_TEST_RUN */
+ };

__u32 family; /* Protocol family (AF_INET, AF_INET6) */
__u32 protocol; /* IP protocol (IPPROTO_TCP, IPPROTO_UDP) */
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index d2a4f04df1da..f8b231bbbe38 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -10,8 +10,10 @@
#include <net/bpf_sk_storage.h>
#include <net/sock.h>
#include <net/tcp.h>
+#include <net/net_namespace.h>
#include <linux/error-injection.h>
#include <linux/smp.h>
+#include <linux/sock_diag.h>

#define CREATE_TRACE_POINTS
#include <trace/events/bpf_test_run.h>
@@ -796,3 +798,106 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
kfree(data);
return ret;
}
+
+int bpf_prog_test_run_sk_lookup(struct bpf_prog *prog, const union bpf_attr *kattr,
+ union bpf_attr __user *uattr)
+{
+ struct bpf_test_timer t = { NO_PREEMPT };
+ struct bpf_prog_array *progs = NULL;
+ struct bpf_sk_lookup_kern ctx = {};
+ u32 repeat = kattr->test.repeat;
+ struct bpf_sk_lookup *user_ctx;
+ u32 retval, duration;
+ int ret = -EINVAL;
+
+ if (prog->type != BPF_PROG_TYPE_SK_LOOKUP)
+ return -EINVAL;
+
+ if (kattr->test.flags || kattr->test.cpu)
+ return -EINVAL;
+
+ if (kattr->test.data_in || kattr->test.data_size_in || kattr->test.data_out ||
+ kattr->test.data_size_out)
+ return -EINVAL;
+
+ if (!repeat)
+ repeat = 1;
+
+ user_ctx = bpf_ctx_init(kattr, sizeof(*user_ctx));
+ if (IS_ERR(user_ctx))
+ return PTR_ERR(user_ctx);
+
+ if (!user_ctx)
+ return -EINVAL;
+
+ if (user_ctx->sk)
+ goto out;
+
+ if (!range_is_zero(user_ctx, offsetofend(typeof(*user_ctx), local_port), sizeof(*user_ctx)))
+ goto out;
+
+ if (user_ctx->local_port > U16_MAX || user_ctx->remote_port > U16_MAX) {
+ ret = -ERANGE;
+ goto out;
+ }
+
+ ctx.family = (u16)user_ctx->family;
+ ctx.protocol = (u16)user_ctx->protocol;
+ ctx.dport = (u16)user_ctx->local_port;
+ ctx.sport = (__force __be16)user_ctx->remote_port;
+
+ switch (ctx.family) {
+ case AF_INET:
+ ctx.v4.daddr = (__force __be32)user_ctx->local_ip4;
+ ctx.v4.saddr = (__force __be32)user_ctx->remote_ip4;
+ break;
+
+#if IS_ENABLED(CONFIG_IPV6)
+ case AF_INET6:
+ ctx.v6.daddr = (struct in6_addr *)user_ctx->local_ip6;
+ ctx.v6.saddr = (struct in6_addr *)user_ctx->remote_ip6;
+ break;
+#endif
+
+ default:
+ ret = -EAFNOSUPPORT;
+ goto out;
+ }
+
+ progs = bpf_prog_array_alloc(1, GFP_KERNEL);
+ if (!progs) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ progs->items[0].prog = prog;
+
+ bpf_test_timer_enter(&t);
+ do {
+ ctx.selected_sk = NULL;
+ retval = BPF_PROG_SK_LOOKUP_RUN_ARRAY(progs, ctx, BPF_PROG_RUN);
+ } while (bpf_test_timer_continue(&t, repeat, &ret, &duration));
+ bpf_test_timer_leave(&t);
+
+ if (ret < 0)
+ goto out;
+
+ user_ctx->cookie = 0;
+ if (ctx.selected_sk) {
+ if (ctx.selected_sk->sk_reuseport && !ctx.no_reuseport) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+
+ user_ctx->cookie = sock_gen_cookie(ctx.selected_sk);
+ }
+
+ ret = bpf_test_finish(kattr, uattr, NULL, 0, retval, duration);
+ if (!ret)
+ ret = bpf_ctx_finish(kattr, uattr, user_ctx, sizeof(*user_ctx));
+
+out:
+ bpf_prog_array_free(progs);
+ kfree(user_ctx);
+ return ret;
+}
diff --git a/net/core/filter.c b/net/core/filter.c
index e2b491665775..815edf7bc439 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -10334,6 +10334,7 @@ static u32 sk_lookup_convert_ctx_access(enum bpf_access_type type,
}

const struct bpf_prog_ops sk_lookup_prog_ops = {
+ .test_run = bpf_prog_test_run_sk_lookup,
};

const struct bpf_verifier_ops sk_lookup_verifier_ops = {
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index e440cd7f32a6..b9ee2ded381a 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -5006,7 +5006,10 @@ struct bpf_pidns_info {

/* User accessible data for SK_LOOKUP programs. Add new fields at the end. */
struct bpf_sk_lookup {
- __bpf_md_ptr(struct bpf_sock *, sk); /* Selected socket */
+ union {
+ __bpf_md_ptr(struct bpf_sock *, sk); /* Selected socket */
+ __u64 cookie; /* Non-zero if socket was selected in PROG_TEST_RUN */
+ };

__u32 family; /* Protocol family (AF_INET, AF_INET6) */
__u32 protocol; /* IP protocol (IPPROTO_TCP, IPPROTO_UDP) */
--
2.27.0


2022-08-01 07:38:02

by Tianchen Ding

[permalink] [raw]
Subject: [PATCH 5.10 1/3] bpf: Consolidate shared test timing code

From: Lorenz Bauer <[email protected]>

commit 607b9cc92bd7208338d714a22b8082fe83bcb177 upstream.

Share the timing / signal interruption logic between different
implementations of PROG_TEST_RUN. There is a change in behaviour
as well. We check the loop exit condition before checking for
pending signals. This resolves an edge case where a signal
arrives during the last iteration. Instead of aborting with
EINTR we return the successful result to user space.

Signed-off-by: Lorenz Bauer <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
[dtcccc: fix conflicts in bpf_test_run()]
Signed-off-by: Tianchen Ding <[email protected]>
---
net/bpf/test_run.c | 140 +++++++++++++++++++++++++--------------------
1 file changed, 78 insertions(+), 62 deletions(-)

diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index eb684f31fd69..d2a4f04df1da 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -16,14 +16,78 @@
#define CREATE_TRACE_POINTS
#include <trace/events/bpf_test_run.h>

+struct bpf_test_timer {
+ enum { NO_PREEMPT, NO_MIGRATE } mode;
+ u32 i;
+ u64 time_start, time_spent;
+};
+
+static void bpf_test_timer_enter(struct bpf_test_timer *t)
+ __acquires(rcu)
+{
+ rcu_read_lock();
+ if (t->mode == NO_PREEMPT)
+ preempt_disable();
+ else
+ migrate_disable();
+
+ t->time_start = ktime_get_ns();
+}
+
+static void bpf_test_timer_leave(struct bpf_test_timer *t)
+ __releases(rcu)
+{
+ t->time_start = 0;
+
+ if (t->mode == NO_PREEMPT)
+ preempt_enable();
+ else
+ migrate_enable();
+ rcu_read_unlock();
+}
+
+static bool bpf_test_timer_continue(struct bpf_test_timer *t, u32 repeat, int *err, u32 *duration)
+ __must_hold(rcu)
+{
+ t->i++;
+ if (t->i >= repeat) {
+ /* We're done. */
+ t->time_spent += ktime_get_ns() - t->time_start;
+ do_div(t->time_spent, t->i);
+ *duration = t->time_spent > U32_MAX ? U32_MAX : (u32)t->time_spent;
+ *err = 0;
+ goto reset;
+ }
+
+ if (signal_pending(current)) {
+ /* During iteration: we've been cancelled, abort. */
+ *err = -EINTR;
+ goto reset;
+ }
+
+ if (need_resched()) {
+ /* During iteration: we need to reschedule between runs. */
+ t->time_spent += ktime_get_ns() - t->time_start;
+ bpf_test_timer_leave(t);
+ cond_resched();
+ bpf_test_timer_enter(t);
+ }
+
+ /* Do another round. */
+ return true;
+
+reset:
+ t->i = 0;
+ return false;
+}
+
static int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat,
u32 *retval, u32 *time, bool xdp)
{
struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = { NULL };
+ struct bpf_test_timer t = { NO_MIGRATE };
enum bpf_cgroup_storage_type stype;
- u64 time_start, time_spent = 0;
- int ret = 0;
- u32 i;
+ int ret;

for_each_cgroup_storage_type(stype) {
storage[stype] = bpf_cgroup_storage_alloc(prog, stype);
@@ -38,10 +102,8 @@ static int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat,
if (!repeat)
repeat = 1;

- rcu_read_lock();
- migrate_disable();
- time_start = ktime_get_ns();
- for (i = 0; i < repeat; i++) {
+ bpf_test_timer_enter(&t);
+ do {
ret = bpf_cgroup_storage_set(storage);
if (ret)
break;
@@ -53,29 +115,8 @@ static int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat,

bpf_cgroup_storage_unset();

- if (signal_pending(current)) {
- ret = -EINTR;
- break;
- }
-
- if (need_resched()) {
- time_spent += ktime_get_ns() - time_start;
- migrate_enable();
- rcu_read_unlock();
-
- cond_resched();
-
- rcu_read_lock();
- migrate_disable();
- time_start = ktime_get_ns();
- }
- }
- time_spent += ktime_get_ns() - time_start;
- migrate_enable();
- rcu_read_unlock();
-
- do_div(time_spent, repeat);
- *time = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
+ } while (bpf_test_timer_continue(&t, repeat, &ret, time));
+ bpf_test_timer_leave(&t);

for_each_cgroup_storage_type(stype)
bpf_cgroup_storage_free(storage[stype]);
@@ -688,18 +729,17 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
const union bpf_attr *kattr,
union bpf_attr __user *uattr)
{
+ struct bpf_test_timer t = { NO_PREEMPT };
u32 size = kattr->test.data_size_in;
struct bpf_flow_dissector ctx = {};
u32 repeat = kattr->test.repeat;
struct bpf_flow_keys *user_ctx;
struct bpf_flow_keys flow_keys;
- u64 time_start, time_spent = 0;
const struct ethhdr *eth;
unsigned int flags = 0;
u32 retval, duration;
void *data;
int ret;
- u32 i;

if (prog->type != BPF_PROG_TYPE_FLOW_DISSECTOR)
return -EINVAL;
@@ -735,39 +775,15 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
ctx.data = data;
ctx.data_end = (__u8 *)data + size;

- rcu_read_lock();
- preempt_disable();
- time_start = ktime_get_ns();
- for (i = 0; i < repeat; i++) {
+ bpf_test_timer_enter(&t);
+ do {
retval = bpf_flow_dissect(prog, &ctx, eth->h_proto, ETH_HLEN,
size, flags);
+ } while (bpf_test_timer_continue(&t, repeat, &ret, &duration));
+ bpf_test_timer_leave(&t);

- if (signal_pending(current)) {
- preempt_enable();
- rcu_read_unlock();
-
- ret = -EINTR;
- goto out;
- }
-
- if (need_resched()) {
- time_spent += ktime_get_ns() - time_start;
- preempt_enable();
- rcu_read_unlock();
-
- cond_resched();
-
- rcu_read_lock();
- preempt_disable();
- time_start = ktime_get_ns();
- }
- }
- time_spent += ktime_get_ns() - time_start;
- preempt_enable();
- rcu_read_unlock();
-
- do_div(time_spent, repeat);
- duration = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
+ if (ret < 0)
+ goto out;

ret = bpf_test_finish(kattr, uattr, &flow_keys, sizeof(flow_keys),
retval, duration);
--
2.27.0


2022-08-01 09:08:47

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH 5.10 0/3] fix build error in bpf selftests

On Mon, Aug 01, 2022 at 03:29:13PM +0800, Tianchen Ding wrote:
> We found a compile error when building tools/testing/selftests/bpf/ on 5.10.y.
> tools/testing/selftests/bpf/prog_tests/sk_lookup.c:1092:15: error: 'struct bpf_sk_lookup' has no member named 'cookie'
> 1092 | if (CHECK(ctx.cookie == 0, "ctx.cookie", "no socket selected\n"))
> | ^
>
> To fix this bug, this patchset backports three patches from upstream:
> https://lore.kernel.org/bpf/[email protected]/
>
> Patch 1 and 2 are necessary for bpf selftests build pass on 5.10.y.
> Patch 3 does not impact building stage, but can avoid a test case
> failure (by skipping it).

Now queued up, thanks.

greg k-h