Youling Tang dbcd7f5faf LoongArch: BPF: Add BPF exception tables ... Inspired by commit 800834285361("bpf, arm64: Add BPF exception tables"), do similar to LoongArch to add BPF exception tables. When a tracing BPF program attempts to read memory without using the bpf_probe_read() helper, the verifier marks the load instruction with the BPF_PROBE_MEM flag. Since the LoongArch JIT does not currently recognize this flag it falls back to the interpreter. Add support for BPF_PROBE_MEM, by appending an exception table to the BPF program. If the load instruction causes a data abort, the fixup infrastructure finds the exception table and fixes up the fault, by clearing the destination register and jumping over the faulting instruction. To keep the compact exception table entry format, inspect the pc in fixup_exception(). A more generic solution would add a "handler" field to the table entry, like on x86, s390 and arm64, etc. Signed-off-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>		2022-12-14 08:36:11 +08:00
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bpf_jit.c	LoongArch: BPF: Add BPF exception tables	2022-12-14 08:36:11 +08:00
bpf_jit.h	LoongArch: BPF: Add BPF exception tables	2022-12-14 08:36:11 +08:00
Makefile