On Wed, 27 Aug 2025 at 17:37, Puranjay Mohan <puranjay@xxxxxxxxxx> wrote: > > BPF loads with BPF_PROBE_MEM(SX) can load from unsafe pointers and the > JIT adds an exception table entry for the JITed instruction which allows > the exeption handler to set the destination register of the load to zero > and continue execution from the next instruction. > > As all arm64 instructions are AARCH64_INSN_SIZE size, the exception > handler can just increment the pc by AARCH64_INSN_SIZE without needing > the exact address of the instruction following the the faulting > instruction. > > Simplify the exception table usage in arm64 JIT by only saving the > destination register in ex->fixup and drop everything related to > the fixup_offset. The fault handler is modified to add AARCH64_INSN_SIZE > to the pc. > > Signed-off-by: Puranjay Mohan <puranjay@xxxxxxxxxx> > Acked-by: Yonghong Song <yonghong.song@xxxxxxxxx> > --- Acked-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
