[PATCH v5 4/8] LSM: lsm_get_self_attr syscall for LSM self attributes

[Mickaël Salaün]

On 09/01/2023 19:07, Casey Schaufler wrote:
> Create a system call lsm_get_self_attr() to provide the security
> module maintained attributes of the current process. Historically
> these attributes have been exposed to user space via entries in
> procfs under /proc/self/attr.
> 
> Attributes are provided as a collection of lsm_ctx structures
> which are placed into a user supplied buffer. Each structure
> identifys the size of the attribute, and the attribute value.
> The format of the attribute value is defined by the security
> module, but will always be \0 terminated. The ctx_len value
> will always be strlen(ctx)+1.
> 
>          ---------------------------
>          | __u32 id                |
>          ---------------------------
>          | __u64 flags             |
>          ---------------------------
>          | __kernel_size_t ctx_len |
>          ---------------------------
>          | __u8 ctx[ctx_len]       |
>          ---------------------------
>          | __u32 id                |
>          ---------------------------
>          | __u64 flags             |
>          ---------------------------
>          | __kernel_size_t ctx_len |
>          ---------------------------
>          | __u8 ctx[ctx_len]       |
>          ---------------------------
> 
> Signed-off-by: Casey Schaufler <casey at schaufler-ca.com>
> ---
>   Documentation/userspace-api/lsm.rst |   9 ++
>   include/linux/syscalls.h            |   3 +
>   include/uapi/linux/lsm.h            |  21 ++++
>   kernel/sys_ni.c                     |   3 +
>   security/Makefile                   |   1 +
>   security/lsm_syscalls.c             | 182 ++++++++++++++++++++++++++++
>   6 files changed, 219 insertions(+)
>   create mode 100644 security/lsm_syscalls.c

For new files (e.g. lsm_syscalls.c), it would be nice to auto-format 
them with clang-format. It helps maintenance by keeping a consistent 
style across commits, which should also help backports, and it avoids 
nitpicking on style issues.