On Thu, Jun 13, 2024 at 10:55 PM Zac Ecob <zacecob@xxxxxxxxxxxxxx> wrote: > > Hi, > > I am receiving an error from the RCU stall detector when using ebpf. Thanks for the report. I reduced the reproducer to the following: 0: R1=ctx() R10=fp0 0: (71) r3 = *(u8 *)(r10 -387) ; R3_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=255,var_off=(0x0; 0xff)) R10=fp0 1: (bc) w7 = (s8)w3 ; R3_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=255,var_off=(0x0; 0xff)) R7_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=127,var_off=(0x0; 0x7f)) 2: (36) if w7 >= 0x2533823b goto pc-3 mark_precise: frame0: last_idx 2 first_idx 0 subseq_idx -1 mark_precise: frame0: regs=r7 stack= before 1: (bc) w7 = (s8)w3 mark_precise: frame0: regs=r3 stack= before 0: (71) r3 = *(u8 *)(r10 -387) 2: R7_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=127,var_off=(0x0; 0x7f)) 3: (b4) w0 = 0 ; R0_w=0 4: (95) exit processed 5 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0 The verifier doesn't process (s8) insn correctly. Yonghong, please take a look.
