Sleepable BPF programs on cgroup {get,set}sockopt #5546
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Enable sleepable cgroup/{get,set}sockopt hooks.
The sleepable BPF programs attached to cgroup/{get,set}sockopt hooks may
received a pointer to the optval in user space instead of a kernel
copy. ctx->optval and ctx->optval_end are the pointers to the
begin and end of the user space buffer if receiving a user space
buffer. No matter where the buffer is, sleepable programs can not
access the content from the pointers directly. They are supposed
to access the buffer through dynptr functions.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Enable libbpf users to define sleepable programs attached on
{get,set}sockopt(). The sleepable programs should be defined with
SEC("cgroup/getsockopt.s") and SEC("cgroup/setsockopt.s") respectively.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Since the buffer pointed by ctx->optval can be in user space, BPF programs in kernel space should not access it directly. They should use kfuncs provided later to access data. Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
The new dynptr type (BPF_DYNPTR_TYPE_CGROUP_SOCKOPT) will be used by BPF programs to create a buffer that can be installed on ctx to replace exisiting optval or user_optval. Installation is only allowed if ctx->flags & BPF_SOCKOPT_FLAG_OPTVAL_REPLACE is true. It is enabled only for sleepable programs on the cgroup/setsockopt hook. BPF programs can install a new buffer holding by a dynptr to increase the size of optval passed to setsockopt(). Installation is not enabled for cgroup/getsockopt since you can not increased a buffer created, by user program, to return data from getsockopt(). Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
…P_SOCKOPT type Do the same test as non-sleepable ones. Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
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Upstream branch: 0a55264 |
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At least one diff in series https://patchwork.kernel.org/project/netdevbpf/list/?series=777577 expired. Closing PR. |
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Pull request for series with
subject: Sleepable BPF programs on cgroup {get,set}sockopt
version: 4
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=777577