From: Kenny Yu <kennyyu@fb.com>
To: <kennyyu@fb.com>
Cc: <andrii@kernel.org>, <ast@kernel.org>, <bpf@vger.kernel.org>,
<daniel@iogearbox.net>, <yhs@fb.com>,
<alexei.starovoitov@gmail.com>, <andrii.nakryiko@gmail.com>,
<phoenix1987@gmail.com>
Subject: [PATCH v7 bpf-next 1/4] bpf: Add support for bpf iterator programs to use sleepable helpers
Date: Mon, 24 Jan 2022 10:54:00 -0800 [thread overview]
Message-ID: <20220124185403.468466-2-kennyyu@fb.com> (raw)
In-Reply-To: <20220124185403.468466-1-kennyyu@fb.com>
This patch allows bpf iterator programs to use sleepable helpers by
changing `bpf_iter_run_prog` to use the appropriate synchronization.
With sleepable bpf iterator programs, we can no longer use
`rcu_read_lock()` and must use `rcu_read_lock_trace()` instead
to protect the bpf program.
Signed-off-by: Kenny Yu <kennyyu@fb.com>
---
kernel/bpf/bpf_iter.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c
index b7aef5b3416d..110029ede71e 100644
--- a/kernel/bpf/bpf_iter.c
+++ b/kernel/bpf/bpf_iter.c
@@ -5,6 +5,7 @@
#include <linux/anon_inodes.h>
#include <linux/filter.h>
#include <linux/bpf.h>
+#include <linux/rcupdate_trace.h>
struct bpf_iter_target_info {
struct list_head list;
@@ -684,11 +685,20 @@ int bpf_iter_run_prog(struct bpf_prog *prog, void *ctx)
{
int ret;
- rcu_read_lock();
- migrate_disable();
- ret = bpf_prog_run(prog, ctx);
- migrate_enable();
- rcu_read_unlock();
+ if (prog->aux->sleepable) {
+ rcu_read_lock_trace();
+ migrate_disable();
+ might_fault();
+ ret = bpf_prog_run(prog, ctx);
+ migrate_enable();
+ rcu_read_unlock_trace();
+ } else {
+ rcu_read_lock();
+ migrate_disable();
+ ret = bpf_prog_run(prog, ctx);
+ migrate_enable();
+ rcu_read_unlock();
+ }
/* bpf program can only return 0 or 1:
* 0 : okay
--
2.30.2
next prev parent reply other threads:[~2022-01-24 18:57 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-13 23:31 [PATCH bpf-next 0/3] Add bpf_access_process_vm helper and sleepable bpf iterator programs Kenny Yu
2022-01-13 23:31 ` [PATCH bpf-next 1/3] bpf: Add bpf_access_process_vm() helper Kenny Yu
2022-01-13 23:31 ` [PATCH bpf-next 2/3] libbpf: Add "iter.s" section for sleepable bpf iterator programs Kenny Yu
2022-01-13 23:31 ` [PATCH bpf-next 3/3] selftests/bpf: Add test " Kenny Yu
2022-01-14 0:48 ` [PATCH v2 bpf-next 0/4] Add bpf_access_process_vm helper and " Kenny Yu
2022-01-14 0:48 ` [PATCH v2 bpf-next 1/4] bpf: Add bpf_access_process_vm() helper Kenny Yu
2022-01-14 0:48 ` [PATCH v2 bpf-next 2/4] bpf: Add support for sleepable programs in bpf_iter_run_prog Kenny Yu
2022-01-14 2:50 ` Alexei Starovoitov
2022-01-14 23:15 ` Kenny Yu
2022-01-14 0:48 ` [PATCH v2 bpf-next 3/4] libbpf: Add "iter.s" section for sleepable bpf iterator programs Kenny Yu
2022-01-14 0:49 ` [PATCH v2 bpf-next 4/4] selftests/bpf: Add test " Kenny Yu
2022-01-14 2:39 ` Alexei Starovoitov
2022-01-14 23:14 ` Kenny Yu
2022-01-15 1:38 ` Andrii Nakryiko
2022-01-15 4:30 ` Kenny Yu
2022-01-15 16:27 ` Gabriele
2022-01-19 16:56 ` Kenny Yu
2022-01-19 18:02 ` [PATCH v3 bpf-next 0/3] Add bpf_access_process_vm helper and " Kenny Yu
2022-01-19 18:02 ` [PATCH v3 bpf-next 1/3] bpf: Add bpf_access_process_vm() helper Kenny Yu
2022-01-19 20:16 ` Alexei Starovoitov
2022-01-19 22:51 ` Kenny Yu
2022-01-19 18:02 ` [PATCH v3 bpf-next 2/3] libbpf: Add "iter.s" section for sleepable bpf iterator programs Kenny Yu
2022-01-19 18:02 ` [PATCH v3 bpf-next 3/3] selftests/bpf: Add test " Kenny Yu
2022-01-19 22:59 ` [PATCH v4 bpf-next 0/3] Add bpf_access_process_vm helper and " Kenny Yu
2022-01-19 22:59 ` [PATCH v4 bpf-next 1/3] bpf: Add bpf_access_process_vm() helper Kenny Yu
2022-01-20 3:45 ` Yonghong Song
2022-01-20 17:11 ` Kenny Yu
2022-01-19 22:59 ` [PATCH v4 bpf-next 2/3] libbpf: Add "iter.s" section for sleepable bpf iterator programs Kenny Yu
2022-01-19 22:59 ` [PATCH v4 bpf-next 3/3] selftests/bpf: Add test " Kenny Yu
2022-01-20 17:29 ` [PATCH v5 bpf-next 0/3] Add bpf_access_process_vm helper and " Kenny Yu
2022-01-20 17:29 ` [PATCH v5 bpf-next 1/3] bpf: Add bpf_access_process_vm() helper Kenny Yu
2022-01-20 22:45 ` Andrii Nakryiko
2022-01-21 2:27 ` Alexei Starovoitov
2022-01-21 17:20 ` Andrii Nakryiko
2022-01-21 17:41 ` Kenny Yu
2022-01-21 17:47 ` Alexei Starovoitov
2022-01-21 18:30 ` Kenny Yu
2022-01-20 17:29 ` [PATCH v5 bpf-next 2/3] libbpf: Add "iter.s" section for sleepable bpf iterator programs Kenny Yu
2022-01-20 17:29 ` [PATCH v5 bpf-next 3/3] selftests/bpf: Add test " Kenny Yu
2022-01-20 22:48 ` Andrii Nakryiko
2022-01-21 19:30 ` [PATCH v6 bpf-next 0/3] Add bpf_copy_from_user_task helper and " Kenny Yu
2022-01-21 19:30 ` [PATCH v6 bpf-next 1/3] bpf: Add bpf_copy_from_user_task() helper Kenny Yu
2022-01-21 19:53 ` Andrii Nakryiko
2022-01-21 20:04 ` Yonghong Song
2022-01-21 20:07 ` Andrii Nakryiko
2022-01-21 21:15 ` Yonghong Song
2022-01-24 17:30 ` Kenny Yu
2022-01-22 9:58 ` Gabriele
2022-01-22 10:08 ` Gabriele
2022-01-21 19:30 ` [PATCH v6 bpf-next 2/3] libbpf: Add "iter.s" section for sleepable bpf iterator programs Kenny Yu
2022-01-21 19:54 ` Andrii Nakryiko
2022-01-21 19:30 ` [PATCH v6 bpf-next 3/3] selftests/bpf: Add test " Kenny Yu
2022-01-21 19:55 ` Andrii Nakryiko
2022-01-24 18:53 ` [PATCH v7 bpf-next 0/4] Add bpf_copy_from_user_task helper and " Kenny Yu
2022-01-24 18:54 ` Kenny Yu [this message]
2022-01-24 22:19 ` [PATCH v7 bpf-next 1/4] bpf: Add support for bpf iterator programs to use sleepable helpers Andrii Nakryiko
2022-01-24 18:54 ` [PATCH v7 bpf-next 2/4] bpf: Add bpf_copy_from_user_task() helper Kenny Yu
2022-01-24 22:18 ` Andrii Nakryiko
2022-01-25 4:06 ` Alexei Starovoitov
2022-01-24 18:54 ` [PATCH v7 bpf-next 3/4] libbpf: Add "iter.s" section for sleepable bpf iterator programs Kenny Yu
2022-01-24 18:54 ` [PATCH v7 bpf-next 4/4] selftests/bpf: Add test " Kenny Yu
2022-01-25 4:10 ` [PATCH v7 bpf-next 0/4] Add bpf_copy_from_user_task helper and " patchwork-bot+netdevbpf
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