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SubjectRe: [bpf-next v3 09/12] bpf: Split out some helper functions
On Mon, Jul 8, 2019 at 6:31 PM Krzesimir Nowak <krzesimir@kinvolk.io> wrote:
>
> The moved functions are generally useful for implementing
> bpf_prog_test_run for other types of BPF programs - they don't have
> any network-specific stuff in them, so I can use them in a test run
> implementation for perf event BPF program too.
>
> Signed-off-by: Krzesimir Nowak <krzesimir@kinvolk.io>

This patch has some whitespace issues (indentation with spaces instead
of tabs in some places), will fix them for v4. Sorry about that.

> ---
> include/linux/bpf.h | 28 +++++
> kernel/bpf/Makefile | 1 +
> kernel/bpf/test_run.c | 212 ++++++++++++++++++++++++++++++++++
> net/bpf/test_run.c | 263 +++++++++++-------------------------------
> 4 files changed, 308 insertions(+), 196 deletions(-)
> create mode 100644 kernel/bpf/test_run.c
>
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index 18f4cc2c6acd..28db8ba57bc3 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -1143,4 +1143,32 @@ static inline u32 bpf_xdp_sock_convert_ctx_access(enum bpf_access_type type,
> }
> #endif /* CONFIG_INET */
>
> +/* Helper functions for bpf_prog_test_run implementations */
> +typedef u32 bpf_prog_run_helper_t(struct bpf_prog *prog, void *ctx,
> + void *private_data);
> +
> +enum bpf_test_run_flags {
> + BPF_TEST_RUN_PLAIN = 0,
> + BPF_TEST_RUN_SETUP_CGROUP_STORAGE = 1 << 0,
> +};
> +
> +int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat, u32 flags,
> + u32 *retval, u32 *duration);
> +
> +int bpf_test_run_cb(struct bpf_prog *prog, void *ctx, u32 repeat, u32 flags,
> + bpf_prog_run_helper_t run_prog, void *private_data,
> + u32 *retval, u32 *duration);
> +
> +int bpf_test_finish(union bpf_attr __user *uattr, u32 retval, u32 duration);
> +
> +void *bpf_receive_ctx(const union bpf_attr *kattr, u32 max_size);
> +
> +int bpf_send_ctx(const union bpf_attr *kattr, union bpf_attr __user *uattr,
> + const void *data, u32 size);
> +
> +void *bpf_receive_data(const union bpf_attr *kattr, u32 max_size);
> +
> +int bpf_send_data(const union bpf_attr *kattr, union bpf_attr __user *uattr,
> + const void *data, u32 size);
> +
> #endif /* _LINUX_BPF_H */
> diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile
> index 29d781061cd5..570fd40288f4 100644
> --- a/kernel/bpf/Makefile
> +++ b/kernel/bpf/Makefile
> @@ -22,3 +22,4 @@ obj-$(CONFIG_CGROUP_BPF) += cgroup.o
> ifeq ($(CONFIG_INET),y)
> obj-$(CONFIG_BPF_SYSCALL) += reuseport_array.o
> endif
> +obj-$(CONFIG_BPF_SYSCALL) += test_run.o
> diff --git a/kernel/bpf/test_run.c b/kernel/bpf/test_run.c
> new file mode 100644
> index 000000000000..0481373da8be
> --- /dev/null
> +++ b/kernel/bpf/test_run.c
> @@ -0,0 +1,212 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/* Copyright (c) 2017 Facebook
> + * Copyright (c) 2019 Tigera, Inc
> + */
> +
> +#include <asm/div64.h>
> +
> +#include <linux/bpf-cgroup.h>
> +#include <linux/bpf.h>
> +#include <linux/err.h>
> +#include <linux/errno.h>
> +#include <linux/filter.h>
> +#include <linux/gfp.h>
> +#include <linux/kernel.h>
> +#include <linux/limits.h>
> +#include <linux/preempt.h>
> +#include <linux/rcupdate.h>
> +#include <linux/sched.h>
> +#include <linux/sched/signal.h>
> +#include <linux/slab.h>
> +#include <linux/timekeeping.h>
> +#include <linux/uaccess.h>
> +
> +static void teardown_cgroup_storage(struct bpf_cgroup_storage **storage)
> +{
> + enum bpf_cgroup_storage_type stype;
> +
> + if (!storage)
> + return;
> + for_each_cgroup_storage_type(stype)
> + bpf_cgroup_storage_free(storage[stype]);
> + kfree(storage);
> +}
> +
> +static struct bpf_cgroup_storage **setup_cgroup_storage(struct bpf_prog *prog)
> +{
> + enum bpf_cgroup_storage_type stype;
> + struct bpf_cgroup_storage **storage;
> + size_t size = MAX_BPF_CGROUP_STORAGE_TYPE;
> +
> + size *= sizeof(struct bpf_cgroup_storage *);
> + storage = kzalloc(size, GFP_KERNEL);
> + for_each_cgroup_storage_type(stype) {
> + storage[stype] = bpf_cgroup_storage_alloc(prog, stype);
> + if (IS_ERR(storage[stype])) {
> + storage[stype] = NULL;
> + teardown_cgroup_storage(storage);
> + return ERR_PTR(-ENOMEM);
> + }
> + }
> + return storage;
> +}
> +
> +static u32 run_bpf_prog(struct bpf_prog *prog, void *ctx, void *private_data)
> +{
> + return BPF_PROG_RUN(prog, ctx);
> +}
> +
> +int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat, u32 flags,
> + u32 *retval, u32 *duration)
> +{
> + return bpf_test_run_cb(prog, ctx, repeat, flags, run_bpf_prog, NULL,
> + retval, duration);
> +}
> +
> +int bpf_test_run_cb(struct bpf_prog *prog, void *ctx, u32 repeat, u32 flags,
> + bpf_prog_run_helper_t run_prog, void *private_data,
> + u32 *retval, u32 *duration)
> +{
> + struct bpf_cgroup_storage **storage = NULL;
> + u64 time_start, time_spent = 0;
> + int ret = 0;
> + u32 i;
> +
> + if (flags & BPF_TEST_RUN_SETUP_CGROUP_STORAGE) {
> + storage = setup_cgroup_storage(prog);
> + if (IS_ERR(storage))
> + return PTR_ERR(storage);
> + }
> +
> + if (!repeat)
> + repeat = 1;
> +
> + rcu_read_lock();
> + preempt_disable();
> + time_start = ktime_get_ns();
> + for (i = 0; i < repeat; i++) {
> + if (storage)
> + bpf_cgroup_storage_set(storage);
> + *retval = run_prog(prog, ctx, private_data);
> +
> + if (signal_pending(current)) {
> + preempt_enable();
> + rcu_read_unlock();
> + teardown_cgroup_storage(storage);
> + return -EINTR;
> + }
> +
> + 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;
> +
> + teardown_cgroup_storage(storage);
> +
> + return ret;
> +}
> +
> +int bpf_test_finish(union bpf_attr __user *uattr, u32 retval, u32 duration)
> +{
> + if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
> + return -EFAULT;
> + if (copy_to_user(&uattr->test.duration, &duration, sizeof(duration)))
> + return -EFAULT;
> + return 0;
> +}
> +
> +static void *bpf_receive_mem(u64 in, u32 in_size, u32 max_size)
> +{
> + void __user *data_in = u64_to_user_ptr(in);
> + void *data;
> + int err;
> +
> + if (!data_in && in_size)
> + return ERR_PTR(-EINVAL);
> + data = kzalloc(max_size, GFP_USER);
> + if (!data)
> + return ERR_PTR(-ENOMEM);
> +
> + if (data_in) {
> + err = bpf_check_uarg_tail_zero(data_in, max_size, in_size);
> + if (err) {
> + kfree(data);
> + return ERR_PTR(err);
> + }
> +
> + in_size = min_t(u32, max_size, in_size);
> + if (copy_from_user(data, data_in, in_size)) {
> + kfree(data);
> + return ERR_PTR(-EFAULT);
> + }
> + }
> + return data;
> +}
> +
> +static int bpf_send_mem(u64 out, u32 out_size, u32 *out_size_write,
> + const void *data, u32 data_size)
> +{
> + void __user *data_out = u64_to_user_ptr(out);
> + int err = -EFAULT;
> + u32 copy_size = data_size;
> +
> + if (!data_out && out_size)
> + return -EINVAL;
> +
> + if (!data || !data_out)
> + return 0;
> +
> + if (copy_size > out_size) {
> + copy_size = out_size;
> + err = -ENOSPC;
> + }
> +
> + if (copy_to_user(data_out, data, copy_size))
> + goto out;
> + if (copy_to_user(out_size_write, &data_size, sizeof(data_size)))
> + goto out;
> + if (err != -ENOSPC)
> + err = 0;
> +out:
> + return err;
> +}
> +
> +void *bpf_receive_data(const union bpf_attr *kattr, u32 max_size)
> +{
> + return bpf_receive_mem(kattr->test.data_in, kattr->test.data_size_in,
> + max_size);
> +}
> +
> +int bpf_send_data(const union bpf_attr *kattr, union bpf_attr __user *uattr,
> + const void *data, u32 size)
> +{
> + return bpf_send_mem(kattr->test.data_out, kattr->test.data_size_out,
> + &uattr->test.data_size_out, data, size);
> +}
> +
> +void *bpf_receive_ctx(const union bpf_attr *kattr, u32 max_size)
> +{
> + return bpf_receive_mem(kattr->test.ctx_in, kattr->test.ctx_size_in,
> + max_size);
> +}
> +
> +int bpf_send_ctx(const union bpf_attr *kattr, union bpf_attr __user *uattr,
> + const void *data, u32 size)
> +{
> + return bpf_send_mem(kattr->test.ctx_out, kattr->test.ctx_size_out,
> + &uattr->test.ctx_size_out, data, size);
> +}
> diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
> index 80e6f3a6864d..fe6b7b1af0cc 100644
> --- a/net/bpf/test_run.c
> +++ b/net/bpf/test_run.c
> @@ -14,97 +14,6 @@
> #define CREATE_TRACE_POINTS
> #include <trace/events/bpf_test_run.h>
>
> -static int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat,
> - u32 *retval, u32 *time)
> -{
> - struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = { NULL };
> - enum bpf_cgroup_storage_type stype;
> - u64 time_start, time_spent = 0;
> - int ret = 0;
> - u32 i;
> -
> - for_each_cgroup_storage_type(stype) {
> - storage[stype] = bpf_cgroup_storage_alloc(prog, stype);
> - if (IS_ERR(storage[stype])) {
> - storage[stype] = NULL;
> - for_each_cgroup_storage_type(stype)
> - bpf_cgroup_storage_free(storage[stype]);
> - return -ENOMEM;
> - }
> - }
> -
> - if (!repeat)
> - repeat = 1;
> -
> - rcu_read_lock();
> - preempt_disable();
> - time_start = ktime_get_ns();
> - for (i = 0; i < repeat; i++) {
> - bpf_cgroup_storage_set(storage);
> - *retval = BPF_PROG_RUN(prog, ctx);
> -
> - if (signal_pending(current)) {
> - ret = -EINTR;
> - break;
> - }
> -
> - 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);
> - *time = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
> -
> - for_each_cgroup_storage_type(stype)
> - bpf_cgroup_storage_free(storage[stype]);
> -
> - return ret;
> -}
> -
> -static int bpf_test_finish(const union bpf_attr *kattr,
> - union bpf_attr __user *uattr, const void *data,
> - u32 size, u32 retval, u32 duration)
> -{
> - void __user *data_out = u64_to_user_ptr(kattr->test.data_out);
> - int err = -EFAULT;
> - u32 copy_size = size;
> -
> - /* Clamp copy if the user has provided a size hint, but copy the full
> - * buffer if not to retain old behaviour.
> - */
> - if (kattr->test.data_size_out &&
> - copy_size > kattr->test.data_size_out) {
> - copy_size = kattr->test.data_size_out;
> - err = -ENOSPC;
> - }
> -
> - if (data_out && copy_to_user(data_out, data, copy_size))
> - goto out;
> - if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size)))
> - goto out;
> - if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
> - goto out;
> - if (copy_to_user(&uattr->test.duration, &duration, sizeof(duration)))
> - goto out;
> - if (err != -ENOSPC)
> - err = 0;
> -out:
> - trace_bpf_test_finish(&err);
> - return err;
> -}
> -
> static void *bpf_test_init(const union bpf_attr *kattr, u32 size,
> u32 headroom, u32 tailroom)
> {
> @@ -125,63 +34,6 @@ static void *bpf_test_init(const union bpf_attr *kattr, u32 size,
> return data;
> }
>
> -static void *bpf_ctx_init(const union bpf_attr *kattr, u32 max_size)
> -{
> - void __user *data_in = u64_to_user_ptr(kattr->test.ctx_in);
> - void __user *data_out = u64_to_user_ptr(kattr->test.ctx_out);
> - u32 size = kattr->test.ctx_size_in;
> - void *data;
> - int err;
> -
> - if (!data_in && !data_out)
> - return NULL;
> -
> - data = kzalloc(max_size, GFP_USER);
> - if (!data)
> - return ERR_PTR(-ENOMEM);
> -
> - if (data_in) {
> - err = bpf_check_uarg_tail_zero(data_in, max_size, size);
> - if (err) {
> - kfree(data);
> - return ERR_PTR(err);
> - }
> -
> - size = min_t(u32, max_size, size);
> - if (copy_from_user(data, data_in, size)) {
> - kfree(data);
> - return ERR_PTR(-EFAULT);
> - }
> - }
> - return data;
> -}
> -
> -static int bpf_ctx_finish(const union bpf_attr *kattr,
> - union bpf_attr __user *uattr, const void *data,
> - u32 size)
> -{
> - void __user *data_out = u64_to_user_ptr(kattr->test.ctx_out);
> - int err = -EFAULT;
> - u32 copy_size = size;
> -
> - if (!data || !data_out)
> - return 0;
> -
> - if (copy_size > kattr->test.ctx_size_out) {
> - copy_size = kattr->test.ctx_size_out;
> - err = -ENOSPC;
> - }
> -
> - if (copy_to_user(data_out, data, copy_size))
> - goto out;
> - if (copy_to_user(&uattr->test.ctx_size_out, &size, sizeof(size)))
> - goto out;
> - if (err != -ENOSPC)
> - err = 0;
> -out:
> - return err;
> -}
> -
> /**
> * range_is_zero - test whether buffer is initialized
> * @buf: buffer to check
> @@ -238,6 +90,36 @@ static void convert_skb_to___skb(struct sk_buff *skb, struct __sk_buff *__skb)
> memcpy(__skb->cb, &cb->data, QDISC_CB_PRIV_LEN);
> }
>
> +static int bpf_net_prog_test_run_finish(const union bpf_attr *kattr,
> + union bpf_attr __user *uattr,
> + const void *data, u32 data_size,
> + const void *ctx, u32 ctx_size,
> + u32 retval, u32 duration)
> +{
> + int ret;
> + union bpf_attr fixed_kattr;
> + const union bpf_attr *kattr_ptr = kattr;
> +
> + /* Clamp copy (in bpf_send_mem) if the user has provided a
> + * size hint, but copy the full buffer if not to retain old
> + * behaviour.
> + */
> + if (!kattr->test.data_size_out && kattr->test.data_out) {
> + fixed_kattr = *kattr;
> + fixed_kattr.test.data_size_out = U32_MAX;
> + kattr_ptr = &fixed_kattr;
> + }
> +
> + ret = bpf_send_data(kattr_ptr, uattr, data, data_size);
> + if (!ret) {
> + ret = bpf_test_finish(uattr, retval, duration);
> + if (!ret && ctx)
> + ret = bpf_send_ctx(kattr_ptr, uattr, ctx, ctx_size);
> + }
> + trace_bpf_test_finish(&ret);
> + return ret;
> +}
> +
> int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
> union bpf_attr __user *uattr)
> {
> @@ -257,7 +139,7 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
> if (IS_ERR(data))
> return PTR_ERR(data);
>
> - ctx = bpf_ctx_init(kattr, sizeof(struct __sk_buff));
> + ctx = bpf_receive_ctx(kattr, sizeof(struct __sk_buff));
> if (IS_ERR(ctx)) {
> kfree(data);
> return PTR_ERR(ctx);
> @@ -307,7 +189,8 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
> ret = convert___skb_to_skb(skb, ctx);
> if (ret)
> goto out;
> - ret = bpf_test_run(prog, skb, repeat, &retval, &duration);
> + ret = bpf_test_run(prog, skb, repeat, BPF_TEST_RUN_SETUP_CGROUP_STORAGE,
> + &retval, &duration);
> if (ret)
> goto out;
> if (!is_l2) {
> @@ -327,10 +210,9 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
> /* bpf program can never convert linear skb to non-linear */
> if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
> size = skb_headlen(skb);
> - ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration);
> - if (!ret)
> - ret = bpf_ctx_finish(kattr, uattr, ctx,
> - sizeof(struct __sk_buff));
> + ret = bpf_net_prog_test_run_finish(kattr, uattr, skb->data, size,
> + ctx, sizeof(struct __sk_buff),
> + retval, duration);
> out:
> kfree_skb(skb);
> bpf_sk_storage_free(sk);
> @@ -365,32 +247,48 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
> rxqueue = __netif_get_rx_queue(current->nsproxy->net_ns->loopback_dev, 0);
> xdp.rxq = &rxqueue->xdp_rxq;
>
> - ret = bpf_test_run(prog, &xdp, repeat, &retval, &duration);
> + ret = bpf_test_run(prog, &xdp, repeat,
> + BPF_TEST_RUN_SETUP_CGROUP_STORAGE,
> + &retval, &duration);
> if (ret)
> goto out;
> if (xdp.data != data + XDP_PACKET_HEADROOM + NET_IP_ALIGN ||
> xdp.data_end != xdp.data + size)
> size = xdp.data_end - xdp.data;
> - ret = bpf_test_finish(kattr, uattr, xdp.data, size, retval, duration);
> + ret = bpf_net_prog_test_run_finish(kattr, uattr, xdp.data, size,
> + NULL, 0, retval, duration);
> out:
> kfree(data);
> return ret;
> }
>
> +struct bpf_flow_dissect_run_data {
> + __be16 proto;
> + int nhoff;
> + int hlen;
> +};
> +
> +static u32 bpf_flow_dissect_run(struct bpf_prog *prog, void *ctx,
> + void *private_data)
> +{
> + struct bpf_flow_dissect_run_data *data = private_data;
> +
> + return bpf_flow_dissect(prog, ctx, data->proto, data->nhoff, data->hlen);
> +}
> +
> int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
> const union bpf_attr *kattr,
> union bpf_attr __user *uattr)
> {
> + struct bpf_flow_dissect_run_data run_data = {};
> u32 size = kattr->test.data_size_in;
> struct bpf_flow_dissector ctx = {};
> u32 repeat = kattr->test.repeat;
> struct bpf_flow_keys flow_keys;
> - u64 time_start, time_spent = 0;
> const struct ethhdr *eth;
> u32 retval, duration;
> void *data;
> int ret;
> - u32 i;
>
> if (prog->type != BPF_PROG_TYPE_FLOW_DISSECTOR)
> return -EINVAL;
> @@ -407,49 +305,22 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
>
> eth = (struct ethhdr *)data;
>
> - if (!repeat)
> - repeat = 1;
> -
> ctx.flow_keys = &flow_keys;
> 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++) {
> - retval = bpf_flow_dissect(prog, &ctx, eth->h_proto, ETH_HLEN,
> - size);
> -
> - 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;
> + run_data.proto = eth->h_proto;
> + run_data.nhoff = ETH_HLEN;
> + run_data.hlen = size;
> + ret = bpf_test_run_cb(prog, &ctx, repeat, BPF_TEST_RUN_PLAIN,
> + bpf_flow_dissect_run, &run_data,
> + &retval, &duration);
> + if (!ret)
> + goto out;
>
> - ret = bpf_test_finish(kattr, uattr, &flow_keys, sizeof(flow_keys),
> - retval, duration);
> + ret = bpf_net_prog_test_run_finish(kattr, uattr, &flow_keys,
> + sizeof(flow_keys), NULL, 0,
> + retval, duration);
>
> out:
> kfree(data);
> --
> 2.20.1
>


--
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Geschäftsführer/Directors: Alban Crequy, Chris Kühl, Iago López Galeiras
Registergericht/Court of registration: Amtsgericht Charlottenburg
Registernummer/Registration number: HRB 171414 B
Ust-ID-Nummer/VAT ID number: DE302207000

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