diff options
| author | Paul Chaignon <paul@isovalent.com> | 2021-12-19 22:36:19 +0100 |
|---|---|---|
| committer | Dmitry Vyukov <dvyukov@google.com> | 2021-12-21 05:33:37 +0100 |
| commit | 761f1410d51aa921477925675bd13b6006b377ca (patch) | |
| tree | e72ba2993e073ea904e6e072690cfb9f32cc7a2b /sys/linux | |
| parent | 249a240f56f88e69fe97cdcf8fb614ade2251958 (diff) | |
sys/linux: support BPF calls to kernel functions
Commit [1] upstream introduced support for BPF calls to kernel
functions, via a new call instruction BPF_PSEUDO_KFUNC_CALL. In this new
instruction, the immediate value is the BTF ID of the function to call
in the kernel.
This commit introduces basic support for this new instruction in
syzkaller. The immediate value will point to a BTF ID, but a fair amount
of additional work would be required to ensure that BTF ID is actually
pointing to a kernel function.
1 - https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e6ac2450d6dee
Signed-off-by: Paul Chaignon <paul@isovalent.com>
Diffstat (limited to 'sys/linux')
| -rw-r--r-- | sys/linux/bpf.txt | 9 | ||||
| -rw-r--r-- | sys/linux/bpf.txt.const | 1 |
2 files changed, 10 insertions, 0 deletions
diff --git a/sys/linux/bpf.txt b/sys/linux/bpf.txt index fcf0a8f07..30fecac48 100644 --- a/sys/linux/bpf.txt +++ b/sys/linux/bpf.txt @@ -229,6 +229,7 @@ bpf_insn [ jmp bpf_insn_jmp call bpf_insn_call_helper func bpf_insn_call_func + kfunc bpf_insn_call_kfunc exit bpf_insn_exit initr0 bpf_insn_init_r0 map_fd bpf_insn_map_fd @@ -343,6 +344,14 @@ bpf_insn_call_func { func int32[-8:8] } +bpf_insn_call_kfunc { + code const[bpf_call_code, int8] + dst const[0, int8:4] + src const[BPF_PSEUDO_KFUNC_CALL, int8:4] + off const[0, int16] + kfunc btf_type_id +} + define bpf_call_code BPF_JMP | BPF_CALL bpf_insn_exit { diff --git a/sys/linux/bpf.txt.const b/sys/linux/bpf.txt.const index 5f8cf4c07..4a4462f3b 100644 --- a/sys/linux/bpf.txt.const +++ b/sys/linux/bpf.txt.const @@ -193,6 +193,7 @@ BPF_PROG_TYPE_XDP = 6 BPF_PSEUDO_BTF_ID = 3 BPF_PSEUDO_CALL = 1 BPF_PSEUDO_FUNC = 4 +BPF_PSEUDO_KFUNC_CALL = 2 BPF_PSEUDO_MAP_FD = 1 BPF_PSEUDO_MAP_IDX = 5 BPF_PSEUDO_MAP_IDX_VALUE = 6 |