diff options
| author | Andrey Ignatov <rdna@fb.com> | 2019-03-19 00:57:10 +0100 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2019-04-12 22:54:59 +0200 |
| commit | 57c3bb725a3dd97d960d7e1cd0845d88de53217f (patch) | |
| tree | dfe95f1ef2311cd1426916df144922892135c9c1 /include | |
| parent | selftests/bpf: Test file_pos field in bpf_sysctl ctx (diff) | |
| download | linux-57c3bb725a3dd97d960d7e1cd0845d88de53217f.tar.xz linux-57c3bb725a3dd97d960d7e1cd0845d88de53217f.zip | |
bpf: Introduce ARG_PTR_TO_{INT,LONG} arg types
Currently the way to pass result from BPF helper to BPF program is to
provide memory area defined by pointer and size: func(void *, size_t).
It works great for generic use-case, but for simple types, such as int,
it's overkill and consumes two arguments when it could use just one.
Introduce new argument types ARG_PTR_TO_INT and ARG_PTR_TO_LONG to be
able to pass result from helper to program via pointer to int and long
correspondingly: func(int *) or func(long *).
New argument types are similar to ARG_PTR_TO_MEM with the following
differences:
* they don't require corresponding ARG_CONST_SIZE argument, predefined
access sizes are used instead (32bit for int, 64bit for long);
* it's possible to use more than one such an argument in a helper;
* provided pointers have to be aligned.
It's easy to introduce similar ARG_PTR_TO_CHAR and ARG_PTR_TO_SHORT
argument types. It's not done due to lack of use-case though.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/bpf.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index e4d4c1771ab0..fd06ada941ad 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -202,6 +202,8 @@ enum bpf_arg_type { ARG_ANYTHING, /* any (initialized) argument is ok */ ARG_PTR_TO_SPIN_LOCK, /* pointer to bpf_spin_lock */ ARG_PTR_TO_SOCK_COMMON, /* pointer to sock_common */ + ARG_PTR_TO_INT, /* pointer to int */ + ARG_PTR_TO_LONG, /* pointer to long */ }; /* type of values returned from helper functions */ |