On Sat, Jan 25, 2025 at 12:30 AM Levi Zim via B4 Relay
<devnull+rsworktech.outlook.com@xxxxxxxxxx> wrote:
>
> From: Levi Zim <rsworktech@xxxxxxxxxxx>
>
> This update brings the new bpf_probe_read_{kernel,user} helpers
>
> Signed-off-by: Levi Zim <rsworktech@xxxxxxxxxxx>
> ---
> tools/include/uapi/linux/bpf.h | 49 ++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 49 insertions(+)
>
> diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
> index 2acf9b33637174bd16b1d12ccc6410c5f55a7ea9..f92cf809b50bc393d54eb0e8de2e1ce2a39e95d0 100644
> --- a/tools/include/uapi/linux/bpf.h
> +++ b/tools/include/uapi/linux/bpf.h
> @@ -5805,6 +5805,52 @@ union bpf_attr {
> * 0 on success.
> *
> * **-ENOENT** if the bpf_local_storage cannot be found.
> + *
> + * long bpf_probe_read_kernel_dynptr(const struct bpf_dynptr *dst, u32 offset, u32 size, const void *unsafe_ptr, u64 flags)
> + * Description
> + * Safely attempt to read *size* bytes from kernel space address
> + * *unsafe_ptr* and store the data in *dst* starting from *offset*.
> + * *flags* is currently unused.
> + * Return
> + * 0 on success.
> + *
> + * **-E2BIG** if *offset* + *len* exceeds the length of *src*'s data
> + *
> + * **-EINVAL** if *src* is an invalid dynptr or doesn't support this
> + * support this helper, or if *flags* is not 0.
> + *
> + * Or other negative errors on failure reading kernel memory.
> + *
> + * long bpf_probe_read_user_dynptr(const struct bpf_dynptr *dst, u32 offset, u32 size, const void *unsafe_ptr, u64 flags)
> + * Description
> + * Safely attempt to read *size* bytes from user space address
> + * *unsafe_ptr* and store the data in *dst* starting from *offset*.
> + * *flags* is currently unused.
> + * Return
> + * 0 on success.
> + *
> + * **-E2BIG** if *offset* + *len* exceeds the length of *src*'s data
> + *
> + * **-EINVAL** if *src* is an invalid dynptr or doesn't support this
> + * support this helper, or if *flags* is not 0.
> + *
> + * Or other negative errors on failure reading user space memory.
> + *
> + * long bpf_copy_from_user_dynptr(const struct bpf_dynptr *dst, u32 offset, u32 size, const void *user_ptr, u64 flags)
> + * Description
> + * Read *size* bytes from user space address *user_ptr* and store
> + * the data in *dst* starting from *offset*.
> + * This is a wrapper of **copy_from_user**\ ().
> + * *flags* is currently unused.
> + * Return
> + * 0 on success.
> + *
> + * **-E2BIG** if *offset* + *len* exceeds the length of *src*'s data
> + *
> + * **-EINVAL** if *src* is an invalid dynptr or doesn't support this
> + * support this helper, or if *flags* is not 0.
> + *
> + * Or other negative errors on failure reading user space memory.
> */
> #define ___BPF_FUNC_MAPPER(FN, ctx...) \
> FN(unspec, 0, ##ctx) \
> @@ -6019,6 +6065,9 @@ union bpf_attr {
> FN(user_ringbuf_drain, 209, ##ctx) \
> FN(cgrp_storage_get, 210, ##ctx) \
> FN(cgrp_storage_delete, 211, ##ctx) \
we probably want to add some big and very noticeable comment here
suggesting kfunc route, to save people time next time. Please consider
adding it as a separate patch for v2.
> + FN(probe_read_kernel_dynptr, 212, ##ctx) \
> + FN(probe_read_user_dynptr, 213, ##ctx) \
> + FN(copy_from_user_dynptr, 214, ##ctx) \
> /* */
>
> /* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't
>
> --
> 2.48.1
>
>
