On 8/10/22 4:25 PM, Benjamin Tissoires wrote:

On Wed, Aug 10, 2022 at 3:44 PM Roberto Sassu [off-list ref] wrote:

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From: Jarkko Sakkinen [mailto:jarkko@kernel.org]
Sent: Tuesday, August 9, 2022 6:55 PM
On Tue, Aug 09, 2022 at 03:45:54PM +0200, Roberto Sassu wrote:

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From: Benjamin Tissoires <redacted>

From: Benjamin Tissoires <redacted>

This allows to declare a kfunc as sleepable and prevents its use in
a non sleepable program.

Nit: "Declare a kfunc as sleepable and prevent its use in a
non-sleepable program."

It's missing the part *how* the patch accomplishes its goals.

I will add:

If an eBPF program is going to call a kfunc declared as sleepable,
eBPF will look at the eBPF program flags. If BPF_F_SLEEPABLE is
not set, execution of that program is denied.

All those changes are looking good to me.

Thanks a lot for keeping pushing on this patch :)

This single one from the series got already applied here:

   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=fa96b24204af42274ec13dfb2f2e6990d7510e55

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Signed-off-by: Benjamin Tissoires <redacted>
Co-developed-by: Yosry Ahmed <redacted>
Signed-off-by: Yosry Ahmed <redacted>
Signed-off-by: Hao Luo <redacted>
---
  Documentation/bpf/kfuncs.rst | 6 ++++++
  include/linux/btf.h          | 1 +
  kernel/bpf/btf.c             | 9 +++++++++
  3 files changed, 16 insertions(+)

diff --git a/Documentation/bpf/kfuncs.rst b/Documentation/bpf/kfuncs.rst
index c0b7dae6dbf5..c8b21de1c772 100644
--- a/Documentation/bpf/kfuncs.rst
+++ b/Documentation/bpf/kfuncs.rst

@@ -146,6 +146,12 @@ that operate (change some property, perform some

operation) on an object that

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  was obtained using an acquire kfunc. Such kfuncs need an unchanged pointer

to

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  ensure the integrity of the operation being performed on the expected object.