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| author | Alexei Starovoitov <ast@plumgrid.com> | 2014-09-26 00:17:04 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-09-26 15:05:15 -0400 |
| commit | 0246e64d9a5fcd4805198de59b9b5cf1f974eb41 (patch) | |
| tree | 3a7b78d9f3dcfb255d0ac9ce5350cef1e195eddf /include/linux/filter.h | |
| parent | cbd357008604925355ae7b54a09137dabb81b580 (diff) | |
| download | lwn-0246e64d9a5fcd4805198de59b9b5cf1f974eb41.tar.gz lwn-0246e64d9a5fcd4805198de59b9b5cf1f974eb41.zip | |
bpf: handle pseudo BPF_LD_IMM64 insn
eBPF programs passed from userspace are using pseudo BPF_LD_IMM64 instructions
to refer to process-local map_fd. Scan the program for such instructions and
if FDs are valid, convert them to 'struct bpf_map' pointers which will be used
by verifier to check access to maps in bpf_map_lookup/update() calls.
If program passes verifier, convert pseudo BPF_LD_IMM64 into generic by dropping
BPF_PSEUDO_MAP_FD flag.
Note that eBPF interpreter is generic and knows nothing about pseudo insns.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/filter.h')
| -rw-r--r-- | include/linux/filter.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h index 4ffc0958d85e..ca95abd2bed1 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -145,6 +145,12 @@ struct bpf_prog_aux; .off = 0, \ .imm = ((__u64) (IMM)) >> 32 }) +#define BPF_PSEUDO_MAP_FD 1 + +/* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */ +#define BPF_LD_MAP_FD(DST, MAP_FD) \ + BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD) + /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */ #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \ |