Re: [PATCH bpf-next v2 15/28] bpf/hid: add new BPF type to trigger commands from userspace
flat view
From: Song Liu <song@kernel.org>
Date: 2022-03-11 00:46:38
Also in:
bpf, linux-kselftest, lkml, netdev
On Fri, Mar 4, 2022 at 9:33 AM Benjamin Tissoires [off-list ref] wrote:
Given that we can not call bpf_hid_raw_request() from within an IRQ, userspace needs to have a way to communicate with the device when it needs. Implement a new type that the caller can run at will without being in an IRQ context. Signed-off-by: Benjamin Tissoires <redacted> ---
[...]
quoted hunk ↗ jump to hunk
+ if (user_size_out && data_out) { + user_size_out = min3(user_size_out, (u32)ctx->size, (u32)ctx->allocated_size); + + if (copy_to_user(data_out, ctx->data, user_size_out)) { + ret = -EFAULT; + goto unlock; + } + + if (copy_to_user(&uattr->test.data_size_out, + &user_size_out, + sizeof(user_size_out))) { + ret = -EFAULT; + goto unlock; + } + } + + if (copy_to_user(&uattr->test.retval, &ctx->u.user.retval, sizeof(ctx->u.user.retval))) { + ret = -EFAULT; + goto unlock;
nit: this goto is not really needed.
quoted hunk ↗ jump to hunk
+ } + +unlock: + kfree(ctx); + + mutex_unlock(&bpf_hid_mutex); + return ret; +}
[...]