Hi, Song reported that a patch he wrote was causing kernel panics on s390. The disassembly printed by the kernel indicated that the stored backchain was not a valid pointer; setting a watchpoint in GDB has shown the culprit: the trampoline. Currently it's implemented without regard for backchain: it clobbers the caller's backchain and causes the issue reported by Song, and also doesn't store its own, making it impossible to unwind past itself. This series fixes both problems. Best regards, Ilya [1] https://lore.kernel.org/bpf/20231004004350.533234-1-song@xxxxxxxxxx/ Ilya Leoshkevich (2): s390/bpf: Fix clobbering the caller's backchain in the trampoline s390/bpf: Fix unwinding past the trampoline arch/s390/net/bpf_jit_comp.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) -- 2.41.0
