1b9b69ecb3
Humans don't write C code like:
u8 *ptr = skb->data;
int imm = 4;
imm += ptr;
but from llvm backend point of view 'imm' and 'ptr' are registers and
imm += ptr may be preferred vs ptr += imm depending which register value
will be used further in the code, while verifier can only recognize ptr += imm.
That caused small unrelated changes in the C code of the bpf program to
trigger rejection by the verifier. Therefore teach the verifier to recognize
both ptr += imm and imm += ptr.
For example:
when R6=pkt(id=0,off=0,r=62) R7=imm22
after r7 += r6 instruction
will be R6=pkt(id=0,off=0,r=62) R7=pkt(id=0,off=22,r=62)
Fixes:
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|---|---|---|
| .. | ||
| Makefile | ||
| arraymap.c | ||
| core.c | ||
| hashtab.c | ||
| helpers.c | ||
| inode.c | ||
| percpu_freelist.c | ||
| percpu_freelist.h | ||
| stackmap.c | ||
| syscall.c | ||
| verifier.c | ||