Files
linux/include
Xu Kuohai 7c3e54cb82 bpf: Eliminate dup/restore of insn_aux_data
The dup/restore of insn_aux_data was introduced to resolve the
inconsistency between insnsi and insn_aux_data arrays, which occurs
on the failure path where insnsi was rolled back to the original
state before constants blinding, while insn_aux_data was not.

After JIT failure, there is only one user, bpf_clear_insn_aux_data(),
that requires insnsi and insn_aux_data to be synchronized. It accesses
both insnsi and insn_aux_data using the same array size and index.

However, the access to insnsi in bpf_clear_insn_aux_data() is not
necessary. It is checked to skip the second slot of an ldimm64 instruction,
whose jt is never set and can be absorbed into the jt check itself.

So remove the access to insnsi from bpf_clear_insn_aux_data(), and add a
specific length field for insn_aux_data to allow it to have a different
length from the insnsi array. Then remove dup/restore of insn_aux_data.

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/5a4528f019c8d2638c019a2f37475cccc16a9503.1785240296.git.xukuohai@huawei.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
2026-08-13 04:36:30 +02:00
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