Alexander Duyck a3f25d614b bpf, arm64: Fix BTI type used for freplace attached functions ... When running an freplace attached bpf program on an arm64 system w were seeing the following issue: Unhandled 64-bit el1h sync exception on CPU47, ESR 0x0000000036000003 -- BTI After a bit of work to track it down I determined that what appeared to be happening is that the 'bti c' at the start of the program was somehow being reached after a 'br' instruction. Further digging pointed me toward the fact that the function was attached via freplace. This in turn led me to build_plt which I believe is invoking the long jump which is triggering this error. To resolve it we can replace the 'bti c' with 'bti jc' and add a comment explaining why this has to be modified as such. Fixes: b2ad54e153 ("bpf, arm64: Implement bpf_arch_text_poke() for arm64") Signed-off-by: Alexander Duyck <alexanderduyck@fb.com> Acked-by: Xu Kuohai <xukuohai@huawei.com> Link: https://lore.kernel.org/r/168926677665.316237.9953845318337455525.stgit@ahduyck-xeon-server.home.arpa Signed-off-by: Alexei Starovoitov <ast@kernel.org>		2023-07-18 15:28:19 -07:00
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bpf_jit_comp.c	bpf, arm64: Fix BTI type used for freplace attached functions	2023-07-18 15:28:19 -07:00
bpf_jit.h	bpf, arm64: Fixed a BTI error on returning to patched function	2023-04-03 17:44:03 +02:00
Makefile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00