diff mbox series

[bpf,v2,2/2] bpf: add missing bpf_read_[un]lock_trace() for syscall program

Message ID 20210809060320.1176782-1-yhs@fb.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series bpf: fix a couple of issues with syscall program | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for bpf
netdev/subject_prefix success Link
netdev/cc_maintainers fail 1 blamed authors not CCed: john.fastabend@gmail.com; 7 maintainers not CCed: netdev@vger.kernel.org john.fastabend@gmail.com davem@davemloft.net kuba@kernel.org songliubraving@fb.com kpsingh@kernel.org kafai@fb.com
netdev/source_inline success Was 0 now: 0
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netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 13 this patch: 13
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 17 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 13 this patch: 13
netdev/header_inline success Link

Commit Message

Yonghong Song Aug. 9, 2021, 6:03 a.m. UTC
Commit 79a7f8bdb159d ("bpf: Introduce bpf_sys_bpf() helper and program type.")
added support for syscall program, which is a sleepable program.
But the program run missed bpf_read_lock_trace()/bpf_read_unlock_trace(),
which is needed to ensure proper rcu callback invocations.
This patch added bpf_read_[un]lock_trace() properly.

Fixes: 79a7f8bdb159d ("bpf: Introduce bpf_sys_bpf() helper and program type.")
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 net/bpf/test_run.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Andrii Nakryiko Aug. 9, 2021, 5:16 p.m. UTC | #1
On Sun, Aug 8, 2021 at 11:03 PM Yonghong Song <yhs@fb.com> wrote:
>
> Commit 79a7f8bdb159d ("bpf: Introduce bpf_sys_bpf() helper and program type.")
> added support for syscall program, which is a sleepable program.
> But the program run missed bpf_read_lock_trace()/bpf_read_unlock_trace(),
> which is needed to ensure proper rcu callback invocations.
> This patch added bpf_read_[un]lock_trace() properly.
>
> Fixes: 79a7f8bdb159d ("bpf: Introduce bpf_sys_bpf() helper and program type.")
> Signed-off-by: Yonghong Song <yhs@fb.com>
> ---

LGTM.

Acked-by: Andrii Nakryiko <andrii@kernel.org>

>  net/bpf/test_run.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
> index 1cc75c811e24..caa16bf30fb5 100644
> --- a/net/bpf/test_run.c
> +++ b/net/bpf/test_run.c
> @@ -7,6 +7,7 @@
>  #include <linux/vmalloc.h>
>  #include <linux/etherdevice.h>
>  #include <linux/filter.h>
> +#include <linux/rcupdate_trace.h>
>  #include <linux/sched/signal.h>
>  #include <net/bpf_sk_storage.h>
>  #include <net/sock.h>
> @@ -951,7 +952,10 @@ int bpf_prog_test_run_syscall(struct bpf_prog *prog,
>                         goto out;
>                 }
>         }
> +
> +       rcu_read_lock_trace();
>         retval = bpf_prog_run_pin_on_cpu(prog, ctx);
> +       rcu_read_unlock_trace();
>
>         if (copy_to_user(&uattr->test.retval, &retval, sizeof(u32))) {
>                 err = -EFAULT;
> --
> 2.30.2
>
diff mbox series

Patch

diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 1cc75c811e24..caa16bf30fb5 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -7,6 +7,7 @@ 
 #include <linux/vmalloc.h>
 #include <linux/etherdevice.h>
 #include <linux/filter.h>
+#include <linux/rcupdate_trace.h>
 #include <linux/sched/signal.h>
 #include <net/bpf_sk_storage.h>
 #include <net/sock.h>
@@ -951,7 +952,10 @@  int bpf_prog_test_run_syscall(struct bpf_prog *prog,
 			goto out;
 		}
 	}
+
+	rcu_read_lock_trace();
 	retval = bpf_prog_run_pin_on_cpu(prog, ctx);
+	rcu_read_unlock_trace();
 
 	if (copy_to_user(&uattr->test.retval, &retval, sizeof(u32))) {
 		err = -EFAULT;